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@article{fds193299,
Author = {CA Lemmon and T Ohashi and HP Erickson},
Title = {Probing the folded state of fibronectin type III domains in
stretched fibrils by measuring buried cysteine
accessibility.},
Journal = {The Journal of biological chemistry},
Volume = {286},
Number = {30},
Pages = {26375-82},
Year = {2011},
Month = {July},
ISSN = {1083-351X},
url = {http://dx.doi.org/10.1074/jbc.M111.240028},
Keywords = {Animals • Cysteine • Elasticity •
Fibronectins • HEK293 Cells • Humans • Mice
• NIH 3T3 Cells • Protein Folding* • Protein
Structure, Tertiary • chemistry* • genetics •
metabolism},
Abstract = {Fibronectin (FN) is an extracellular matrix protein that is
assembled into fibrils by cells during tissue morphogenesis
and wound healing. FN matrix fibrils are highly elastic, but
the mechanism of elasticity has been debated: it may be
achieved by mechanical unfolding of FN-III domains or by a
conformational change of the molecule without domain
unfolding. Here, we investigate the folded state of FN-III
domains in FN fibrils by measuring the accessibility of
buried cysteines. Four of the 15 FN-III domains (III-2, -3,
-9, and -11) appear to unfold in both stretched fibrils and
in solution, suggesting that these domains spontaneously
open and close even in the absence of tension. Two FN-III
domains (III-6 and -12) appear to unfold only in fibrils and
not in solution. These results suggest that domain unfolding
can at best contribute partially to the 4-fold extensibility
of fibronectin fibrils.},
Language = {eng},
Doi = {10.1074/jbc.M111.240028},
Key = {fds193299}
}
@article{fds193310,
Author = {M Osawa and HP Erickson},
Title = {Inside-out Z rings--constriction with and without GTP
hydrolysis.},
Journal = {Molecular microbiology},
Volume = {81},
Number = {2},
Pages = {571-9},
Year = {2011},
Month = {July},
ISSN = {1365-2958},
url = {http://dx.doi.org/10.1111/j.1365-2958.2011.07716.x},
Keywords = {Bacterial Proteins • Cytoskeletal Proteins •
Guanosine Triphosphate • Hydrolysis • Liposomes
• Models, Biological • Models, Chemical •
Models, Molecular • Protein Multimerization* •
metabolism*},
Abstract = {The bacterial tubulin homologue FtsZ forms a ring-like
structure called the Z ring that drives cytokinesis. We
showed previously that FtsZ-YFP-mts, which has a short
amphipathic helix (mts) on its C terminus that inserts into
the membrane, can assemble contractile Z rings in tubular
liposomes without any other protein. Here we study
mts-FtsZ-YFP, where the membrane tether is switched to the
opposite side of the protofilament. This assembled
'inside-out' Z rings that wrapped around the outside surface
of tubular liposomes. The inside-out Z rings were highly
dynamic, and generated a constriction force that squeezed
the tubular liposomes from outside. This is consistent with
models where the constriction force is generated by curved
protofilaments bending the membrane. We used this system to
test how GTP hydrolysis by FtsZ is involved in Z-ring
constriction. Without GTP hydrolysis, Z rings could still
assemble and generate an initial constriction. However, the
constriction quickly stopped, suggesting that Z rings became
rigidly stabilized in the absence of GTP hydrolysis. We
propose that remodelling of the Z ring, mediated by GTP
hydrolysis and exchange of subunits, is necessary for the
continuous constriction.},
Language = {eng},
Doi = {10.1111/j.1365-2958.2011.07716.x},
Key = {fds193310}
}
@article{fds193306,
Author = {Y Chen and HP Erickson},
Title = {Conformational changes of FtsZ reported by tryptophan
mutants.},
Journal = {Biochemistry},
Volume = {50},
Number = {21},
Pages = {4675-84},
Year = {2011},
Month = {May},
ISSN = {1520-4995},
url = {http://dx.doi.org/10.1021/bi200106d},
Keywords = {Acrylamide • Bacterial Proteins • Cytoskeletal
Proteins • Microscopy, Electron • Models,
Molecular • Mutation • Protein Conformation •
Spectrometry, Fluorescence • Tryptophan •
chemistry • chemistry* • genetics •
genetics*},
Abstract = {E. coli FtsZ has no native tryptophan. We showed previously
that the mutant FtsZ L68W gave a 2.5-fold increase in trp
fluorescence when assembly was induced by GTP. L68 is
probably buried in the protofilament interface upon
assembly, causing the fluorescence increase. In the present
study we introduced trp residues at several other locations
and examined them for assembly-induced fluorescence changes.
L189W, located on helix H7 and buried between the N- and
C-terminal subdomains, showed a large fluorescence increase,
comparable to L68W. This may reflect a shift or rotation of
the two subdomains relative to each other. L160W showed a
smaller increase in fluorescence, and Y222W a decrease in
fluorescence, upon assembly. These two are located on the
surface of the N and C subdomains, near the domain boundary.
The changes in fluorescence may reflect movements of the
domains or of nearby side chains. We prepared a double
mutant Y222W/S151C and coupled ATTO-655 to the cys. The Cα
of trp in the C-terminal subdomain was 10 Å away from that
of the cys in the N-terminal subdomain, permitting the ATTO
to make van der Waals contact with the trp. The ATTO
fluorescence showed strong tryptophan-induced quenching. The
quenching was reduced following assembly, consistent with a
movement apart of the two subdomains. Movements of one to
several angstroms are probably sufficient to account for the
changes in trp fluorescence and trp-induced quenching of
ATTO. Assembly in GDP plus DEAE dextran produces tubular
polymers that are related to the highly curved, mini-ring
conformation. No change in trp fluorescence was observed
upon assembly of these tubes, suggesting that the mini-ring
conformation is the same as that of a relaxed, monomeric
FtsZ.},
Language = {eng},
Doi = {10.1021/bi200106d},
Key = {fds193306}
}
@article{fds193304,
Author = {HP Erickson and DE Anderson and M Osawa},
Title = {FtsZ in bacterial cytokinesis: cytoskeleton and force
generator all in one.},
Journal = {Microbiology and molecular biology reviews :
MMBR},
Volume = {74},
Number = {4},
Pages = {504-28},
Year = {2010},
Month = {December},
ISSN = {1098-5557},
url = {http://dx.doi.org/10.1128/MMBR.00021-10},
Keywords = {Bacteria • Bacterial Proteins • Cytokinesis •
Cytoskeletal Proteins • Cytoskeleton • chemistry
• cytology • metabolism* •
physiology*},
Abstract = {FtsZ, a bacterial homolog of tubulin, is well established as
forming the cytoskeletal framework for the cytokinetic ring.
Recent work has shown that purified FtsZ, in the absence of
any other division proteins, can assemble Z rings when
incorporated inside tubular liposomes. Moreover, these
artificial Z rings can generate a constriction force,
demonstrating that FtsZ is its own force generator. Here we
review light microscope observations of how Z rings assemble
in bacteria. Assembly begins with long-pitch helices that
condense into the Z ring. Once formed, the Z ring can
transition to short-pitch helices that are suggestive of its
structure. FtsZ assembles in vitro into short protofilaments
that are ∼30 subunits long. We present models for how
these protofilaments might be further assembled into the Z
ring. We discuss recent experiments on assembly dynamics of
FtsZ in vitro, with particular attention to how two
regulatory proteins, SulA and MinC, inhibit assembly. Recent
efforts to develop antibacterial drugs that target FtsZ are
reviewed. Finally, we discuss evidence of how FtsZ generates
a constriction force: by protofilament bending into a curved
conformation.},
Language = {eng},
Doi = {10.1128/MMBR.00021-10},
Key = {fds193304}
}
@article{fds193309,
Author = {HP Erickson and M Osawa},
Title = {Cell division without FtsZ--a variety of redundant
mechanisms.},
Journal = {Molecular microbiology},
Volume = {78},
Number = {2},
Pages = {267-70},
Year = {2010},
Month = {October},
ISSN = {1365-2958},
Keywords = {Archaea • Archaeal Proteins • Bacteria •
Bacterial Proteins • Cell Division* • Cytoskeletal
Proteins • Endosomal Sorting Complexes Required for
Transport • cytology • physiology •
physiology*},
Language = {eng},
Key = {fds193309}
}
@article{fds193298,
Author = {D Popp and M Iwasa and HP Erickson and A Narita and Y Maéda and RC
Robinson},
Title = {Suprastructures and dynamic properties of Mycobacterium
tuberculosis FtsZ.},
Journal = {The Journal of biological chemistry},
Volume = {285},
Number = {15},
Pages = {11281-9},
Year = {2010},
Month = {April},
ISSN = {1083-351X},
url = {http://dx.doi.org/10.1074/jbc.M109.084079},
Keywords = {Bacterial Proteins • Biophysics • Cations •
Cytoskeletal Proteins • Cytoskeleton •
Hydrogen-Ion Concentration • Kinetics • Light
• Microscopy, Electron • Microscopy, Fluorescence
• Mycobacterium tuberculosis • Polymers •
Scattering, Radiation • Time Factors • chemistry
• metabolism • metabolism* •
methods},
Abstract = {Tuberculosis causes the most death in humans by any
bacterium. Drug targeting of bacterial cytoskeletal proteins
requires detailed knowledge of the various filamentous
suprastructures and dynamic properties. Here, we have
investigated by high resolution electron microscopy the
assembly of cell division protein and microtubule homolog
FtsZ from Mycobacterium tuberculosis (MtbFtsZ) in vitro in
the presence of various monovalent salts, crowding agents
and polycations. Supramolecular structures, including
two-dimensional rings, three-dimensional toroids, and
multistranded helices formed in the presence of molecular
crowding, were similar to those observed by fluorescence
microscopy in bacteria in vivo. Dynamic properties of
MtbFtsZ filaments were visualized by light scattering and
real time total internal reflection fluorescence microscopy.
Interestingly, MtbFtsZ revealed a form of dynamic
instability at steady state. Cation-induced condensation
phenomena of bacterial cytomotive polymers have not been
investigated in any detail, although it is known that many
bacteria can contain high amounts of polycations, which may
modulate the prokaryotic cytoskeleton. We find that above a
threshold concentration of polycations which varied with the
valence of the cation, ionic strength, and pH, MtbFtsZ
mainly formed sheets. The general features of these
cation-induced condensation phenomena could be explained in
the framework of the Manning condensation theory. Chirality
and packing defects limited the dimensions of sheets and
toroids at steady state as predicted by theoretical models.
In first approximation simple physical principles seem to
govern the formation of MtbFtsZ suprastructures.},
Language = {eng},
Doi = {10.1074/jbc.M109.084079},
Key = {fds193298}
}
@article{fds193303,
Author = {M Osawa and DE Anderson and HP Erickson},
Title = {Curved FtsZ protofilaments generate bending forces on
liposome membranes.},
Journal = {The EMBO journal},
Volume = {28},
Number = {22},
Pages = {3476-84},
Year = {2009},
Month = {November},
ISSN = {1460-2075},
url = {http://dx.doi.org/10.1038/emboj.2009.277},
Keywords = {Bacterial Proteins • Cytoskeletal Proteins •
Cytoskeleton • Liposomes • Membranes •
Models, Biological • Models, Molecular • Protein
Structure, Quaternary • Structure-Activity Relationship
• Tensile Strength • Torsion, Mechanical •
chemistry • chemistry* • metabolism •
metabolism* • physiology • physiology*},
Abstract = {We have created FtsZ-YFP-mts where an amphipathic helix on
the C-terminus tethers FtsZ to the membrane. When
incorporated inside multi-lamellar tubular liposomes,
FtsZ-YFP-mts can assemble Z rings that generate a
constriction force. When added to the outside of liposomes,
FtsZ-YFP-mts bound and produced concave depressions, bending
the membrane in the same direction as the Z ring inside
liposomes. Prominent membrane tubules were then extruded at
the intersections of concave depressions. We tested the
effect of moving the membrane-targeting sequence (mts) from
the C-terminus to the N-terminus, which is approximately 180
degrees from the C-terminal tether. When mts-FtsZ-YFP was
applied to the outside of liposomes, it generated convex
bulges, bending the membrane in the direction opposite to
the concave depressions. We conclude that FtsZ
protofilaments have a fixed direction of curvature, and the
direction of membrane bending depends on which side of the
bent protofilament the mts is attached to. This supports
models in which the FtsZ constriction force is generated by
protofilament bending.},
Language = {eng},
Doi = {10.1038/emboj.2009.277},
Key = {fds193303}
}
@article{fds193301,
Author = {R Kenjale and G Meng and DL Fink and T Juehne and T Ohashi and HP Erickson and G Waksman and JW St Geme 3rd},
Title = {Structural determinants of autoproteolysis of the
Haemophilus influenzae Hap autotransporter.},
Journal = {Infection and immunity},
Volume = {77},
Number = {11},
Pages = {4704-13},
Year = {2009},
Month = {November},
ISSN = {1098-5522},
url = {http://dx.doi.org/10.1128/IAI.00598-09},
Keywords = {Amino Acid Sequence • Bacterial Outer Membrane Proteins
• Blotting, Western • Haemophilus influenzae
• Molecular Sequence Data • Mutagenesis,
Site-Directed • Protein Structure, Quaternary •
Sequence Homology, Amino Acid • Serine Endopeptidases
• chemistry* • enzymology* • genetics •
metabolism* • pathogenicity},
Abstract = {Haemophilus influenzae is a gram-negative bacterium that
initiates infection by colonizing the upper respiratory
tract. The H. influenzae Hap autotransporter protein
mediates adherence, invasion, and microcolony formation in
assays with respiratory epithelial cells and presumably
facilitates colonization. The serine protease activity of
Hap is associated with autoproteolytic cleavage and
extracellular release of the HapS passenger domain, leaving
the Hapbeta C-terminal domain embedded in the outer
membrane. Cleavage occurs most efficiently at the LN1036-37
peptide bond and to a lesser extent at three other sites. In
this study, we utilized site-directed mutagenesis, homology
modeling, and assays with a peptide library to characterize
the structural determinants of Hap proteolytic activity and
cleavage specificity. In addition, we used homology modeling
to predict the S1, S2, and S4 subsite residues of the Hap
substrate groove. Our results indicate that the P1 and P2
positions at the Hap cleavage sites are critical for
cleavage, with leucine preferred over larger hydrophobic
residues or other amino acids in these positions. The
substrate groove is formed by L263 and N274 at the S1
subsite, R264 at the S2 subsite, and E265 at the S4 subsite.
This information may facilitate design of approaches to
block Hap activity and interfere with H. influenzae
colonization.},
Language = {eng},
Doi = {10.1128/IAI.00598-09},
Key = {fds193301}
}
@article{fds193302,
Author = {Y Chen and HP Erickson},
Title = {FtsZ filament dynamics at steady state: subunit exchange
with and without nucleotide hydrolysis.},
Journal = {Biochemistry},
Volume = {48},
Number = {28},
Pages = {6664-73},
Year = {2009},
Month = {July},
ISSN = {1520-4995},
url = {http://dx.doi.org/10.1021/bi8022653},
Keywords = {Actin Cytoskeleton • Amino Acid Substitution •
Bacterial Proteins • Buffers • Cytoskeletal
Proteins • Escherichia coli • Fluorescence
Resonance Energy Transfer • GTP Phosphohydrolases
• Guanosine Diphosphate • Guanosine Triphosphate
• Hydrolysis • Kinetics • Magnesium •
Potassium • Protein Subunits • Rubidium •
drug effects • metabolism • metabolism* •
pharmacology • ultrastructure},
Abstract = {We have measured three aspects of FtsZ filament dynamics at
steady state: rates of GTP hydrolysis, subunit exchange
between protofilaments, and disassembly induced by dilution
or excess GDP. All three reactions were slowed with an
increase in the potassium concentration from 100 to 500 mM,
via replacement of potassium with rubidium, or with an
increase in the magnesium concentration from 5 to 20 mM.
Electron microscopy showed that the polymers assembled under
the conditions of fastest assembly were predominantly short,
one-stranded protofilaments, whereas under conditions of
slower dynamics, the protofilaments tended to associate into
long, thin bundles. We suggest that exchange of subunits
between protofilaments at steady state involves two separate
mechanisms: (1) fragmentation or dissociation of subunits
from protofilament ends following GTP hydrolysis and (2)
reversible association and dissociation of subunits from
protofilament ends independent of hydrolysis. Exchange of
nucleotides on these recycling subunits could give the
appearance of exchange directly into the polymer. Several of
our observations suggest that exchange of nucleotide can
take place on these recycling subunits, but not directly
into the FtsZ polymer. Annealing of protofilaments was
demonstrated for the L68W mutant in EDTA buffer but not in
Mg buffer, where rapid cycling of subunits may obscure the
effect of annealing. We also reinvestigated the nucleotide
composition of FtsZ polymers at steady state. We found that
the GDP:GTP ratio was 50:50 for concentrations of GTP >100
microM, significantly higher than the 20:80 ratio previously
reported at 20 microM GTP.},
Language = {eng},
Doi = {10.1021/bi8022653},
Key = {fds193302}
}
@article{fds193296,
Author = {HP Erickson},
Title = {Modeling the physics of FtsZ assembly and force
generation.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America},
Volume = {106},
Number = {23},
Pages = {9238-43},
Year = {2009},
Month = {June},
ISSN = {1091-6490},
url = {http://dx.doi.org/10.1073/pnas.0902258106},
Keywords = {Bacterial Proteins • Cytoskeletal Proteins •
Escherichia coli • Guanosine Triphosphate •
Models, Biological • Tubulin • chemistry* •
metabolism • metabolism*},
Abstract = {The tubulin homolog FtsZ is the major cytoskeletal protein
in bacterial cytokinesis. It can generate a constriction
force on the bacterial membrane or inside tubular liposomes.
Several models have recently been proposed for how this
force might be generated. These fall into 2 categories. The
first is based on a conformational change from a straight to
a curved protofilament. The simplest "hydrolyze and bend"
model proposes a 22 degrees bend at every interface
containing a GDP. New evidence suggests another curved
conformation with a 2.5 degrees bend at every interface and
that the relation of curvature to GTP hydrolysis is more
complicated than previously thought. However, FtsZ
protofilaments do appear to be mechanically rigid enough to
bend membranes. A second category of models is based on
lateral bonding between protofilaments, postulating that a
contraction could be generated when protofilaments slide to
increase the number of lateral bonds. Unfortunately these
lateral bond models have ignored the contribution of subunit
entropy when adding bond energies; if included, the
mechanism is seen to be invalid. Finally, I address recent
models that try to explain how protofilaments
1-subunit-thick show a cooperative assembly.},
Language = {eng},
Doi = {10.1073/pnas.0902258106},
Key = {fds193296}
}
@article{fds193297,
Author = {T Ohashi and AM Augustus and HP Erickson},
Title = {Transient opening of fibronectin type III (FNIII) domains:
the interaction of the third FNIII domain of FN with
anastellin.},
Journal = {Biochemistry},
Volume = {48},
Number = {19},
Pages = {4189-97},
Year = {2009},
Month = {May},
ISSN = {1520-4995},
url = {http://dx.doi.org/10.1021/bi900001g},
Keywords = {Anilino Naphthalenesulfonates • Binding Sites •
Fibronectins • Fluorescence Resonance Energy Transfer
• Fluorescent Dyes • Green Fluorescent Proteins
• Kinetics • Models, Molecular • Mutation
• Peptide Fragments • Protein Binding •
Protein Folding • Protein Structure, Tertiary •
Spectrometry, Fluorescence • Spectrometry, Mass,
Matrix-Assisted Laser Desorption-Ionization •
chemistry* • genetics • metabolism •
metabolism*},
Abstract = {We previously reported that the fibronectin (FN) type III
domains of FN may unfold to interact with anastellin and
form FN aggregates. In the present study, we have focused on
the interaction between anastellin and the third FN type III
domain (III3), which is a key anastellin binding site on FN.
Anastellin binding to III3 was monitored by
8-anilino-1-naphthalene sulfonate (ANS) fluorescence. ANS
binding to anastellin dramatically increased its emission
intensity, but this was reduced to half by the addition of
III3, suggesting that ANS and III3 share a common
hydrophobic binding site on anastellin. An engineered mutant
of III3 that was stabilized by an intrachain disulfide bond
did not interact with anastellin, as seen by its failure to
interfere with ANS binding to anastellin. We also mutated
hydrophobic core residues to destabilize III3 and found that
these mutants were still capable of interacting with
anastellin. Anastellin binding to III3 was also monitored
using an intramolecular green fluorescent protein
(GFP)-based fluorescence resonance energy transfer (FRET)
construct, in which III3 was flanked by two GFP variants
(III3-FRET). Anastellin bound to III3-FRET and caused an
increase in the FRET signal. The dissociation constant was
estimated to be approximately 210 nM. The binding kinetics
of anastellin to III3-FRET fit a first-order reaction with a
half-time of approximately 30 s; the kinetics with
destabilized III3 mutants were even faster. Matrix-assisted
laser desorption ionization-time-of-flight (MALDI-TOF) mass
spectrometry suggested that the middle part of III3 became
destabilized and protease sensitive upon anastellin binding.
Thus, the stability of III3 seems to be a key factor in
anastellin binding.},
Language = {eng},
Doi = {10.1021/bi900001g},
Key = {fds193297}
}
@article{fds156445,
Author = {D Popp and M Iwasa and A Narita and HP Erickson and Y
Maéda},
Title = {FtsZ condensates: an in vitro electron microscopy
study.},
Journal = {Biopolymers},
Volume = {91},
Number = {5},
Pages = {340-50},
Year = {2009},
Month = {May},
ISSN = {0006-3525},
url = {http://dx.doi.org/10.1002/bip.21136},
Keywords = {Bacterial Proteins • Cations • Cytoskeletal
Proteins • Edetic Acid • Escherichia coli •
Microscopy, Electron • Sodium • drug effects
• pharmacology • ultrastructure*},
Abstract = {In vivo cell division protein FtsZ from E. coli forms rings
and spirals which have only been observed by low resolution
light microscopy. We show that these suprastructures are
likely formed by molecular crowding which is a predominant
factor in prokaryotic cells and enhances the weak lateral
bonds between proto-filaments. Although FtsZ assembles into
single proto-filaments in dilute aqueous buffer, with
crowding agents above a critical concentration, it forms
polymorphic supramolecular structures including rings and
toroids (with multiple protofilaments) about 200 nm in
diameter, similar in appearance to DNA toroids, and helices
with pitches of several hundred nm as well as long, linear
bundles. Helices resemble those observed in vivo, whereas
the rings and toroids may represent a novel energy minimized
state of FtsZ, at a later stage of Z-ring constriction. We
shed light on the molecular arrangement of FtsZ filaments
within these suprastructures using high resolution electron
microscopy.},
Language = {eng},
Doi = {10.1002/bip.21136},
Key = {fds156445}
}
@article{fds193308,
Author = {T Ohashi and HP Erickson},
Title = {Revisiting the mystery of fibronectin multimers: the
fibronectin matrix is composed of fibronectin dimers
cross-linked by non-covalent bonds.},
Journal = {Matrix biology : journal of the International Society for
Matrix Biology},
Volume = {28},
Number = {3},
Pages = {170-5},
Year = {2009},
Month = {April},
ISSN = {1569-1802},
url = {http://dx.doi.org/10.1016/j.matbio.2009.03.002},
Keywords = {Animals • Detergents • Electrophoresis,
Polyacrylamide Gel • Extracellular Matrix •
Fibronectins • Mice • Microfilament Proteins
• Microscopy, Electron • NIH 3T3 Cells •
Physicochemical Processes* • Protein Multimerization*
• chemistry • chemistry* • isolation &
purification • ultrastructure},
Abstract = {Fibronectin (FN) matrix fibrils have long been thought to be
formed by disulfide-bonded FN multimers, although there is
no direct evidence that they are covalently linked with each
other. To understand the biochemical properties of these
fibrils, we extracted a crude FN matrix from FN-YPet
transfected 3T3 cell culture using 0.2% deoxycholate and
DNase. The insoluble extracted matrix preserved fibrillar
structures and a major portion of the extracted proteins
migrated as FN monomers on an SDS gel under reducing
conditions. Under non-reducing conditions, some FN molecules
appeared to be trapped at the top of the stacking gel. We
tested this by mixing fluorescently labeled FN dimers with
the extracted matrix just before loading on an SDS gel, and
found that most of them were trapped with the extracted
proteins at the top of the stacking gel. These results
suggested that some components of the extracted matrix
plugged the stacking gel and FN dimers were trapped with
them. Rotary shadowing electron microscopy showed that the
extracted matrix had some fibers that resembled fibrillin
microfibrils. Peptide mass fingerprinting confirmed the
presence of fibrillin in the extracted matrix. Fibrillin is
known to form disulfide-bonded multimers and it is likely to
be one of the components that plug the stacking gel and trap
FN molecules in this system. The phenomenon by which FN
molecules appear to migrate as multimers on SDS gels is thus
an artifact rising from the presence of other large
components in the extract. We conclude that FN matrix
fibrils are made of FN dimers that are further cross-linked
by non-covalent protein-protein bonds.},
Language = {eng},
Doi = {10.1016/j.matbio.2009.03.002},
Key = {fds193308}
}
@article{fds156446,
Author = {J Xu and E Bae and Q Zhang and DS Annis and HP Erickson and DF
Mosher},
Title = {Display of cell surface sites for fibronectin assembly is
modulated by cell adherence to (1)F3 and C-terminal modules
of fibronectin.},
Journal = {PloS one},
Volume = {4},
Number = {1},
Pages = {e4113},
Year = {2009},
ISSN = {1932-6203},
url = {http://dx.doi.org/10.1371/journal.pone.0004113},
Keywords = {Animals • Cell Adhesion • Cells, Cultured •
Fibronectins • Focal Adhesions • Humans •
Mice • Mice, Knockout • Peptide Fragments •
Recombinant Proteins • Vinculin • chemistry •
chemistry* • genetics • metabolism •
metabolism* • physiology*},
Abstract = {BACKGROUND: Fibronectin-null cells assemble soluble
fibronectin shortly after adherence to a substrate coated
with intact fibronectin but not when adherent to the
cell-binding domain of fibronectin (modules (7)F3-(10)F3).
Interactions of adherent cells with regions of adsorbed
fibronectin other than modules (7)F3-(10)F3, therefore, are
required for early display of the cell surface sites that
initiate and direct fibronectin assembly. RESULTS: To
identify these regions, coatings of proteolytically derived
or recombinant pieces of fibronectin containing modules in
addition to (7)F3-(10)F3 were tested for effects on
fibronectin assembly by adherent fibronectin-null
fibroblasts. Pieces as large as one comprising modules
(2)F3-(14)F3, which include the heparin-binding and cell
adhesion domains, were not effective in supporting
fibronectin assembly. Addition of module (1)F3 or the
C-terminal modules to modules (2)F3-(14)F3 resulted in some
activity, and addition of both (1)F3 and the C-terminal
modules resulted in a construct, (1)F3-C, that best mimicked
the activity of a coating of intact fibronectin. Constructs
(1)F3-C V0, (1)F3-C V64, and (1)F3-C Delta(V(15)F3(10)F1)
were all able to support fibronectin assembly, suggesting
that (1)F3 through (11)F1 and/or (12)F1 were important for
activity. Coatings in which the active parts of (1)F3-C were
present in different proteins were much less active than
intact (1)F3-C. CONCLUSIONS: These results suggest that
(1)F3 acts together with C-terminal modules to induce
display of fibronectin assembly sites on adherent
cells.},
Language = {eng},
Doi = {10.1371/journal.pone.0004113},
Key = {fds156446}
}
@article{fds193300,
Author = {HP Erickson},
Title = {Size and shape of protein molecules at the nanometer level
determined by sedimentation, gel filtration, and electron
microscopy.},
Journal = {Biological procedures online},
Volume = {11},
Pages = {32-51},
Year = {2009},
ISSN = {1480-9222},
url = {http://dx.doi.org/10.1007/s12575-009-9008-x},
Abstract = {An important part of characterizing any protein molecule is
to determine its size and shape. Sedimentation and gel
filtration are hydrodynamic techniques that can be used for
this medium resolution structural analysis. This review
collects a number of simple calculations that are useful for
thinking about protein structure at the nanometer level.
Readers are reminded that the Perrin equation is generally
not a valid approach to determine the shape of proteins.
Instead, a simple guideline is presented, based on the
measured sedimentation coefficient and a calculated maximum
S, to estimate if a protein is globular or elongated. It is
recalled that a gel filtration column fractionates proteins
on the basis of their Stokes radius, not molecular weight.
The molecular weight can be determined by combining gradient
sedimentation and gel filtration, techniques available in
most biochemistry laboratories, as originally proposed by
Siegel and Monte. Finally, rotary shadowing and negative
stain electron microscopy are powerful techniques for
resolving the size and shape of single protein molecules and
complexes at the nanometer level. A combination of
hydrodynamics and electron microscopy is especially
powerful.},
Language = {eng},
Doi = {10.1007/s12575-009-9008-x},
Key = {fds193300}
}
@article{fds193305,
Author = {M Osawa and HP Erickson},
Title = {Chapter 1 - Tubular liposomes with variable permeability for
reconstitution of FtsZ rings.},
Journal = {Methods in enzymology},
Volume = {464},
Pages = {3-17},
Year = {2009},
ISSN = {1557-7988},
url = {http://dx.doi.org/10.1016/S0076-6879(09)64001-5},
Keywords = {Bacterial Proteins • Cytoskeletal Proteins •
Liposomes • Membrane Proteins • Molecular Biology
• Permeability • chemistry • metabolism*
• methods*},
Abstract = {We have developed a system for producing tubular
multilamellar liposomes that incorporate the protein FtsZ on
the inside. We start with a mixture of spherical
multilamellar liposomes with FtsZ initially on the outside.
Shearing forces generated by applying a coverslip most
likely distort some of the spherical liposomes into a
tubular shape, and causes some to leak and incorporate FtsZ
inside. We describe protocols for liposome preparation, and
for preparing membrane-targeted FtsZ that can assemble
contractile Z rings inside the tubular liposomes. We also
describe the characterization of the multilamellar liposomes
in terms of the permeability or leakiness for a small
fluorescent dye and larger protein molecules. These
liposomes may be useful for reconstitution of other
biological systems.},
Language = {eng},
Doi = {10.1016/S0076-6879(09)64001-5},
Key = {fds193305}
}
@article{fds193307,
Author = {GE White and HP Erickson},
Title = {The coiled coils of cohesin are conserved in animals, but
not in yeast.},
Journal = {PloS one},
Volume = {4},
Number = {3},
Pages = {e4674},
Year = {2009},
ISSN = {1932-6203},
url = {http://dx.doi.org/10.1371/journal.pone.0004674},
Keywords = {Adenosine Triphosphatases • Animals • Cell Cycle
Proteins • Chromosomal Proteins, Non-Histone •
Conserved Sequence* • DNA-Binding Proteins • Gene
Expression • Humans • Multiprotein Complexes
• Protein Conformation • Species Specificity
• Structural Homology, Protein • Yeasts •
chemistry* • physiology},
Abstract = {BACKGROUND: The SMC proteins are involved in DNA repair,
chromosome condensation, and sister chromatid cohesion
throughout Eukaryota. Long, anti-parallel coiled coils are a
prominent feature of SMC proteins, and are thought to serve
as spacer rods to provide an elongated structure and to
separate domains. We reported recently that the coiled coils
of mammalian condensin (SMC2/4) showed moderate sequence
divergence (approximately 10-15%) consistent with their
functioning as spacer rods. The coiled coils of mammalian
cohesins (SMC1/3), however, were very highly constrained,
with amino acid sequence divergence typically <0.5%. These
coiled coils are among the most highly conserved mammalian
proteins, suggesting that they make extensive contacts over
their entire surface. RESULTS: Here, we broaden our initial
analysis of condensin and cohesin to include additional
vertebrate and invertebrate organisms and multiple species
of yeast. We found that the coiled coils of SMC1/3 are
highly constrained in Drosophila and other insects, and more
generally across all animal species. However, in yeast they
are no more constrained than the coils of SMC2/4 and
Ndc80/Nuf2p, suggesting that they are serving primarily as
spacer rods. CONCLUSIONS: SMC1/3 functions for sister
chromatid cohesion in all species. Since its coiled coils
apparently serve only as spacer rods in yeast, it is likely
that this is sufficient for sister chromatid cohesion in all
species. This suggests an additional function in animals
that constrains the sequence of the coiled coils. Several
recent studies have demonstrated that cohesin has a role in
gene expression in post-mitotic neurons of Drosophila, and
other animal cells. Some variants of human Cornelia de Lange
Syndrome involve mutations in human SMC1/3. We suggest that
the role of cohesin in gene expression may involve intimate
contact of the coiled coils of SMC1/3, and impose the
constraint on sequence divergence.},
Language = {eng},
Doi = {10.1371/journal.pone.0004674},
Key = {fds193307}
}
@article{fds193311,
Author = {CA Sontag and H Sage and HP Erickson},
Title = {BtubA-BtubB heterodimer is an essential intermediate in
protofilament assembly.},
Journal = {PloS one},
Volume = {4},
Number = {9},
Pages = {e7253},
Year = {2009},
ISSN = {1932-6203},
url = {http://dx.doi.org/10.1371/journal.pone.0007253},
Keywords = {Bacterial Outer Membrane Proteins • Bacterial Proteins
• Chlamydiaceae • Crystallography, X-Ray •
Cytoskeleton • Dimerization • Escherichia coli
Proteins • Guanosine Triphosphate • Hydrolysis
• Kinetics • Light • Membrane Transport
Proteins • Models, Molecular • Mutation •
Point Mutation • Polymers • Scattering, Radiation
• Tubulin • chemistry • chemistry* •
genetics • metabolism*},
Abstract = {BACKGROUND: BtubA and BtubB are two tubulin-like genes found
in the bacterium Prosthecobacter. Our work and a previous
crystal structure suggest that BtubB corresponds to
alpha-tubulin and BtubA to beta-tubulin. A 1:1 mixture of
the two proteins assembles into tubulin-like protofilaments,
which further aggregate into pairs and bundles. The proteins
also form a BtubA/B heterodimer, which appears to be a
repeating subunit in the protofilament. RESULTS: We have
designed point mutations to disrupt the longitudinal
interfaces bonding subunits into protofilaments. The mutants
are in two classes, within dimers and between dimers. We
have characterized one mutant of each class for BtubA and
BtubB. When mixed 1:1 with a wild type partner, none of the
mutants were capable of assembly. An excess of between-dimer
mutants could depolymerize preformed wild type polymers,
while within-dimer mutants had no activity. CONCLUSIONS: An
essential first step in assembly of BtubA + BtubB is
formation of a heterodimer. An excess of between-dimer
mutants depolymerize wild type BtubA/B by sequestering the
partner wild type subunit into inactive dimers. Within-dimer
mutants cannot form dimers and have no activity.},
Language = {eng},
Doi = {10.1371/journal.pone.0007253},
Key = {fds193311}
}
@article{fds156450,
Author = {M Osawa and DE Anderson and HP Erickson},
Title = {Reconstitution of contractile FtsZ rings in
liposomes.},
Journal = {Science (New York, N.Y.), United States},
Volume = {320},
Number = {5877},
Pages = {792-4},
Year = {2008},
Month = {May},
ISSN = {1095-9203},
Keywords = {Bacterial Proteins • Cell Membrane • Cytoskeletal
Proteins • Escherichia coli • Escherichia coli
Proteins • Liposomes • Membrane Proteins •
Protein Binding • Protein Transport • Recombinant
Proteins • genetics • physiology*},
Abstract = {FtsZ is a tubulin homolog and the major cytoskeletal protein
in bacterial cell division. It assembles into the Z ring,
which contains FtsZ and a dozen other division proteins, and
constricts to divide the cell. We have constructed a
membrane-targeted FtsZ (FtsZ-mts) by splicing an amphipathic
helix to its C terminus. When mixed with lipid vesicles,
FtsZ-mts was incorporated into the interior of some tubular
vesicles. There it formed multiple Z rings that could move
laterally in both directions along the length of the
liposome and coalesce into brighter Z rings. Brighter Z
rings produced visible constrictions in the liposome,
suggesting that FtsZ itself can assemble the Z ring and
generate a force. No other proteins were needed for assembly
and force generation.},
Key = {fds156450}
}
@article{fds156449,
Author = {Y Chen and HP Erickson},
Title = {In vitro assembly studies of FtsZ/tubulin-like proteins
(TubZ) from Bacillus plasmids: evidence for a capping
mechanism.},
Journal = {The Journal of biological chemistry, United
States},
Volume = {283},
Number = {13},
Pages = {8102-9},
Year = {2008},
Month = {March},
ISSN = {0021-9258},
Keywords = {Bacillus anthracis • Bacillus thuringiensis •
Bacterial Proteins • Cytoskeletal Proteins •
Escherichia coli Proteins • GTP Phosphohydrolases
• Guanosine Triphosphate • Microscopy, Electron
• Plasmids • Tubulin • genetics •
genetics* • metabolism • metabolism* •
ultrastructure},
Abstract = {Proteins with a weak sequence similarity to tubulin and FtsZ
are expressed from large plasmids of Bacillus anthracis and
Bacillus thuringiensis and are probably involved in plasmid
segregation. Previously designated RepX and TubZ, we
designate them here as TubZ-Ba and TubZ-Bt. We have
expressed and purified the proteins for in vitro studies.
TubZ-Ba and TubZ-Bt share only 21% amino acid identity, but
they have remarkably similar biochemical properties. They
both assemble into two-stranded filaments and larger bundles
above a critical concentration, and they hydrolyze GTP at a
very high rate, approximately 20 GTP min(-1) TubZ(-1).
Assembly is also supported by GTPgammaS. A tiny amount of
GTPgammaS stabilizes polymers assembled in GTP and inhibits
the GTPase by a mechanism involving cooperativity. The
nucleotide in the polymers is almost 100% GDP, which is
similar to microtubules but very different from the 20-30%
GDP in FtsZ polymers. This suggests that the TubZ polymers
have a capping mechanism that may be related to the GTP cap
that produces dynamic instability of microtubules.},
Key = {fds156449}
}
@article{fds156447,
Author = {EK Moioli and PA Clark and M Chen and JE Dennis and HP Erickson and SL
Gerson, JJ Mao},
Title = {Synergistic actions of hematopoietic and mesenchymal
stem/progenitor cells in vascularizing bioengineered
tissues.},
Journal = {PLoS ONE, United States},
Volume = {3},
Number = {12},
Pages = {e3922},
Year = {2008},
ISSN = {1932-6203},
Abstract = {Poor angiogenesis is a major road block for tissue repair.
The regeneration of virtually all tissues is limited by
angiogenesis, given the diffusion of nutrients, oxygen, and
waste products is limited to a few hundred micrometers. We
postulated that co-transplantation of hematopoietic and
mesenchymal stem/progenitor cells improves angiogenesis of
tissue repair and hence the outcome of regeneration. In this
study, we tested this hypothesis by using bone as a model
whose regeneration is impaired unless it is vascularized.
Hematopoietic stem/progenitor cells (HSCs) and mesenchymal
stem/progenitor cells (MSCs) were isolated from each of
three healthy human bone marrow samples and reconstituted in
a porous scaffold. MSCs were seeded in micropores of 3D
calcium phosphate (CP) scaffolds, followed by infusion of
gel-suspended CD34(+) hematopoietic cells.
Co-transplantation of CD34(+) HSCs and CD34(-) MSCs in
microporous CP scaffolds subcutaneously in the dorsum of
immunocompromised mice yielded vascularized tissue. The
average vascular number of co-transplanted CD34(+) and MSC
scaffolds was substantially greater than MSC transplantation
alone. Human osteocalcin was expressed in the micropores of
CP scaffolds and was significantly increased upon
co-transplantation of MSCs and CD34(+) cells. Human nuclear
staining revealed the engraftment of transplanted human
cells in vascular endothelium upon co-transplantation of
MSCs and CD34(+) cells. Based on additional in vitro results
of endothelial differentiation of CD34(+) cells by vascular
endothelial growth factor (VEGF), we adsorbed VEGF with
co-transplanted CD34(+) and MSCs in the microporous CP
scaffolds in vivo, and discovered that vascular number and
diameter further increased, likely owing to the promotion of
endothelial differentiation of CD34(+) cells by VEGF.
Together, co-transplantation of hematopoietic and
mesenchymal stem/progenitor cells may improve the
regeneration of vascular dependent tissues such as bone,
adipose, muscle and dermal grafts, and may have implications
in the regeneration of internal organs.},
Key = {fds156447}
}
@article{fds156451,
Author = {Y Chen and DE Anderson and M Rajagopalan and HP Erickson},
Title = {Assembly dynamics of Mycobacterium tuberculosis
FtsZ.},
Journal = {The Journal of biological chemistry, United
States},
Volume = {282},
Number = {38},
Pages = {27736-43},
Year = {2007},
Month = {September},
ISSN = {0021-9258},
Keywords = {Bacterial Proteins • Biochemistry • Cytoskeletal
Proteins • Dose-Response Relationship, Drug •
Escherichia coli • Fluorescence Resonance Energy
Transfer • Guanosine Diphosphate • Guanosine
Triphosphate • Hydrogen-Ion Concentration •
Kinetics • Microscopy, Electron • Models, Chemical
• Mycobacterium tuberculosis • Polymers •
Time Factors • chemistry • metabolism •
metabolism* • methods},
Abstract = {We have investigated the assembly of FtsZ from Mycobacterium
tuberculosis (MtbFtsZ). Electron microscopy confirmed the
previous observation that MtbFtsZ assembled into long,
two-stranded filaments at pH 6.5. However, we found that
assembly at pH 7.2 or 7.7 produced predominantly short,
one-stranded protofilaments, similar to those of Escherichia
coli FtsZ (EcFtsZ). Near pH 7, which is close to the pH of
M. tuberculosis cytoplasm, MtbFtsZ formed a mixture of
single- and two-stranded filaments. We developed a
fluorescence resonance energy transfer assay to measure the
kinetics of initial assembly and the dynamic properties at
steady state. Assembly of MtbFtsZ reached a plateau after
60-100 s, about 10 times slower than EcFtsZ. The initial
assembly kinetics were similar at pH 6.5 and 7.7, despite
the striking difference in the polymer structures. Both were
fit with a cooperative assembly mechanism involving a weak
dimer nucleus, similar to EcFtsZ but with slower kinetics.
Subunit turnover and GTPase at steady state were also about
10 times slower for MtbFtsZ than for EcFtsZ. Specifically,
the half-time for subunit turnover in vitro at pH 7.7 was 42
s for MtbFtsZ compared with 5.5 s for EcFtsZ. Photobleaching
studies in vivo showed a range of turnover half-times with
an average of 25 s for MtbFtsZ as compared with 9 s for
EcFtsZ.},
Key = {fds156451}
}
@article{fds113235,
Author = {S Takahashi and M Leiss and M Moser and T Ohashi and T Kitao and D
Heckmann, A Pfeifer and H Kessler and J Takagi and HP Erickson and R
Fässler},
Title = {The RGD motif in fibronectin is essential for development
but dispensable for fibril assembly.},
Journal = {The Journal of cell biology},
Volume = {178},
Number = {1},
Pages = {167-78},
Year = {2007},
Month = {July},
ISSN = {0021-9525},
url = {http://dx.doi.org/10.1083/jcb.200703021},
Keywords = {Amino Acid Motifs • Amino Acid Sequence • Amino
Acid Substitution • Animals • Aspartic Acid •
Binding Sites • Cell Line, Transformed •
Dimerization • Disulfides • Embryo, Mammalian
• Extracellular Matrix • Fibroblasts •
Fibronectins • Heterozygote • Integrin alphaVbeta3
• Mice • Oligopeptides • Protein Binding
• Protein Structure, Tertiary • Recombinant
Proteins • Reticulin • Solubility • chemistry
• chemistry* • cytology • genetics •
metabolism • metabolism*},
Abstract = {Fibronectin (FN) is secreted as a disulfide-bonded FN dimer.
Each subunit contains three types of repeating modules:
FN-I, FN-II, and FN-III. The interactions of alpha5beta1 or
alphav integrins with the RGD motif of FN-III repeat 10
(FN-III10) are considered an essential step in the assembly
of FN fibrils. To test this hypothesis in vivo, we replaced
the RGD motif with the inactive RGE in mice. FN-RGE
homozygous embryos die at embryonic day 10 with shortened
posterior trunk, absent tail bud-derived somites, and severe
vascular defects resembling the phenotype of alpha5
integrin-deficient mice. Surprisingly, the absence of a
functional RGD motif in FN did not compromise assembly of an
FN matrix in mutant embryos or on mutant cells. Matrix
assembly assays and solid-phase binding assays reveal that
alphavbeta3 integrin assembles FN-RGE by binding an isoDGR
motif in FN-I5, which is generated by the nonenzymatic
rearrangement of asparagines (N) into an iso-aspartate
(iso-D). Our findings demonstrate that FN contains a novel
motif for integrin binding and fibril formation whose
activity is controlled by amino acid modification.},
Language = {eng},
Doi = {10.1083/jcb.200703021},
Key = {fds113235}
}
@article{fds113233,
Author = {HP Erickson},
Title = {Evolution of the cytoskeleton.},
Journal = {BioEssays : news and reviews in molecular, cellular and
developmental biology},
Volume = {29},
Number = {7},
Pages = {668-77},
Year = {2007},
Month = {July},
ISSN = {0265-9247},
url = {http://dx.doi.org/10.1002/bies.20601},
Keywords = {Amino Acid Sequence • Animals • Bacterial Proteins
• Cytoskeletal Proteins • Cytoskeleton •
Evolution, Molecular* • Humans • Molecular
Sequence Data • Sequence Homology, Amino Acid •
Tubulin • chemistry • genetics • metabolism
• metabolism*},
Abstract = {The eukaryotic cytoskeleton appears to have evolved from
ancestral precursors related to prokaryotic FtsZ and MreB.
FtsZ and MreB show 40-50% sequence identity across different
bacterial and archaeal species. Here I suggest that this
represents the limit of divergence that is consistent with
maintaining their functions for cytokinesis and cell shape.
Previous analyses have noted that tubulin and actin are
highly conserved across eukaryotic species, but so divergent
from their prokaryotic relatives as to be hardly
recognizable from sequence comparisons. One suggestion for
this extreme divergence of tubulin and actin is that it
occurred as they evolved very different functions from FtsZ
and MreB. I will present new arguments favoring this
suggestion, and speculate on pathways. Moreover, the extreme
conservation of tubulin and actin across eukaryotic species
is not due to an intrinsic lack of variability, but is
attributed to their acquisition of elaborate mechanisms for
assembly dynamics and their interactions with multiple motor
and binding proteins. A new structure-based sequence
alignment identifies amino acids that are conserved from
FtsZ to tubulins. The highly conserved amino acids are not
those forming the subunit core or protofilament interface,
but those involved in binding and hydrolysis of
GTP.},
Language = {eng},
Doi = {10.1002/bies.20601},
Key = {fds113233}
}
@article{fds113234,
Author = {T Ohashi and SD Galiacy and G Briscoe and HP Erickson},
Title = {An experimental study of GFP-based FRET, with application to
intrinsically unstructured proteins.},
Journal = {Protein science : a publication of the Protein
Society},
Volume = {16},
Number = {7},
Pages = {1429-38},
Year = {2007},
Month = {July},
ISSN = {0961-8368},
url = {http://dx.doi.org/10.1110/ps.072845607},
Keywords = {Algorithms • Electrophoresis, Polyacrylamide Gel •
Fluorescence Resonance Energy Transfer • Green
Fluorescent Proteins • Luminescent Proteins •
Models, Molecular • Protein Conformation •
Proteins • chemistry • chemistry* •
methods*},
Abstract = {We have experimentally studied the fluorescence resonance
energy transfer (FRET) between green fluorescent protein
(GFP) molecules by inserting folded or intrinsically
unstructured proteins between CyPet and Ypet. We discovered
that most of the enhanced FRET signal previously reported
for this pair was due to enhanced dimerization, so we
engineered a monomerizing mutation into each. An insert
containing a single fibronectin type III domain (3.7 nm
end-to-end) gave a moderate FRET signal while a two-domain
insert (7.0 nm) gave no FRET. We then tested unstructured
proteins of various lengths, including the charged-plus-PQ
domain of ZipA, the tail domain of alpha-adducin, and the
C-terminal tail domain of FtsZ. The structures of these FRET
constructs were also studied by electron microscopy and
sedimentation. A 12 amino acid linker and the N-terminal 33
amino acids of the charged domain of the ZipA gave strong
FRET signals. The C-terminal 33 amino acids of the PQ domain
of the ZipA and several unstructured proteins with 66-68
amino acids gave moderate FRET signals. The 150 amino acid
charged-plus-PQ construct gave a barely detectable FRET
signal. FRET efficiency was calculated from the decreased
donor emission to estimate the distance between donor and
acceptor. The donor-acceptor distance varied for
unstructured inserts of the same length, suggesting that
they had variable stiffness (persistence length). We
conclude that GFP-based FRET can be useful for studying
intrinsically unstructured proteins, and we present a range
of calibrated protein inserts to experimentally determine
the distances that can be studied.},
Language = {eng},
Doi = {10.1110/ps.072845607},
Key = {fds113234}
}
@article{fds156452,
Author = {SP Ng and KS Billings and T Ohashi, MD Allen and RB Best and LG Randles and HP Erickson and J Clarke},
Title = {Designing an extracellular matrix protein with enhanced
mechanical stability.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America, United States},
Volume = {104},
Number = {23},
Pages = {9633-7},
Year = {2007},
Month = {June},
ISSN = {0027-8424},
Keywords = {Amino Acid Sequence • Biophysical Phenomena •
Biophysics • Cell Adhesion • Crystallization
• Fibronectins • Humans • Microscopy, Atomic
Force • Models, Molecular* • Molecular Sequence
Data • Mutation • Protein Conformation* •
Protein Engineering • Protein Structure, Tertiary
• Sequence Alignment • Tenascin • chemistry*
• genetics • methods* • physiology},
Abstract = {The extracellular matrix proteins tenascin and fibronectin
experience significant mechanical forces in vivo. Both
contain a number of tandem repeating homologous fibronectin
type III (fnIII) domains, and atomic force microscopy
experiments have demonstrated that the mechanical strength
of these domains can vary significantly. Previous work has
shown that mutations in the core of an fnIII domain from
human tenascin (TNfn3) reduce the unfolding force of that
domain significantly: The composition of the core is
apparently crucial to the mechanical stability of these
proteins. Based on these results, we have used rational
redesign to increase the mechanical stability of the 10th
fnIII domain of human fibronectin, FNfn10, which is directly
involved in integrin binding. The hydrophobic core of FNfn10
was replaced with that of the homologous, mechanically
stronger TNfn3 domain. Despite the extensive substitution,
FNoTNc retains both the three-dimensional structure and the
cell adhesion activity of FNfn10. Atomic force microscopy
experiments reveal that the unfolding forces of the
engineered protein FNoTNc increase by approximately 20% to
match those of TNfn3. Thus, we have specifically designed a
protein with increased mechanical stability. Our results
demonstrate that core engineering can be used to change the
mechanical strength of proteins while retaining functional
surface interactions.},
Key = {fds156452}
}
@article{fds113237,
Title = {-PDFs of most of my recent papers are available at http://www.cellbio.duke.edu/Faculty/Research/Erickson.html},
Year = {2007},
Key = {fds113237}
}
@article{fds113236,
Author = {M Osawa and HP Erickson},
Title = {FtsZ from divergent foreign bacteria can function for cell
division in Escherichia coli.},
Journal = {Journal of bacteriology},
Volume = {188},
Number = {20},
Pages = {7132-40},
Year = {2006},
Month = {October},
ISSN = {0021-9193},
url = {http://dx.doi.org/10.1128/JB.00647-06},
Keywords = {Bacillus subtilis • Bacterial Proteins • Cell
Division • Cytoplasm • Cytoskeletal Proteins
• Escherichia coli • Genes, Reporter •
Genetic Complementation Test • Luminescent Proteins
• Microscopy, Fluorescence • Mycoplasma pulmonis
• Protein Structure, Tertiary • Recombinant Fusion
Proteins • Recombinant Proteins • Suppression,
Genetic • analysis • chemistry • cytology
• genetics • genetics* • growth & development
• metabolism • physiology*},
Abstract = {FtsZs from Mycoplasma pulmonis (MpuFtsZ) and Bacillus
subtilis (BsFtsZ) are only 46% and 53% identical in amino
acid sequence to FtsZ from Escherichia coli (EcFtsZ). In the
present study we show that MpuFtsZ and BsFtsZ can function
for cell division in E. coli provided we make two
modifications. First, we replaced their C-terminal tails
with that from E. coli, giving the foreign FtsZ the binding
site for E. coli FtsA and ZipA. Second, we selected for
mutations in the E. coli genome that facilitated division by
the foreign FtsZs. These suppressor strains arose at a
relatively high frequency of 10(-3) to 10(-5), suggesting
that they involve loss-of-function mutations in multigene
pathways. These pathways may be negative regulators of FtsZ
or structural pathways that facilitate division by slightly
defective FtsZ. Related suppressor strains were obtained for
EcFtsZ containing certain point mutations or insertions of
yellow fluorescent protein. The ability of highly divergent
FtsZs to function for division in E. coli is consistent with
a two-part mechanism. FtsZ assembles the Z ring, and perhaps
generates the constriction force, through self interactions;
the downstream division proteins remodel the peptidoglycan
wall by interacting with each other and the wall. The
C-terminal peptide of FtsZ, which binds FtsA, provides the
link between FtsZ assembly and peptidoglycan
remodeling.},
Language = {eng},
Doi = {10.1128/JB.00647-06},
Key = {fds113236}
}
@article{fds113231,
Author = {GE White and HP Erickson},
Title = {Sequence divergence of coiled coils--structural rods, myosin
filament packing, and the extraordinary conservation of
cohesins.},
Journal = {Journal of structural biology},
Volume = {154},
Number = {2},
Pages = {111-21},
Year = {2006},
Month = {May},
ISSN = {1047-8477},
url = {http://dx.doi.org/10.1016/j.jsb.2006.01.001},
Keywords = {Actins • Amino Acid Sequence • Animals •
Antigens, Nuclear • Cell Cycle Proteins •
Chromosomal Proteins, Non-Histone • Conserved Sequence
• Evolution, Molecular • Genetic Variation •
Humans • Membrane Proteins • Models, Molecular
• Myosins • Nuclear Matrix-Associated Proteins
• Nuclear Proteins • Protein Conformation •
Protein Subunits • Structure-Activity Relationship
• chemistry • chemistry* •
genetics},
Abstract = {The amino acid sequences of the long, anti-parallel coiled
coils of the cohesin subunits SMC1 and SMC3 are almost
totally conserved in mammals. To understand this exceptional
conservation more broadly, we analyzed amino acid sequence
variation for several groups of coiled-coil proteins. Some
long coiled coils, including giantin, NuMA, and Ndc80p/Nuf2p
diverge approximately 20% from humans to rodents, suggesting
they function as spacer rods, whose sequence divergence is
constrained only by the need to maintain the coiled-coil
structure. Other coiled coils such as skeletal muscle
myosin, intermediate filaments, and the lamins diverge only
1-3%. We suggest that this sequence divergence is
constrained by the extensive packing contacts over the
entire surface of the coiled-coil. The coiled coils of
SMC5/6 and SMC2/4 (condensin) are slightly more constrained
than the presumed spacer rods, diverging 10-15%. Conversely,
the coiled coils of SMC1/3 (cohesin) diverge only 0.0-1.0%.
This extreme constraint suggests that the entire surface of
the coiled coil is intimately involved in the mechanism of
sister chromatid cohesion. Direct binding of the coiled
coils to chromatin, or perhaps the need to avoid such
binding, are two possible mechanisms. Finally, analysis of
the heptad repeat shows that the a and d positions are more
constrained in spacer rods, and the bcefg positions more
constrained in skeletal muscle myosin.},
Language = {eng},
Doi = {10.1016/j.jsb.2006.01.001},
Key = {fds113231}
}
@article{fds113229,
Author = {NI Abu-Lail and T Ohashi and RL Clark and HP Erickson and S
Zauscher},
Title = {Understanding the elasticity of fibronectin fibrils:
unfolding strengths of FN-III and GFP domains measured by
single molecule force spectroscopy.},
Journal = {Matrix biology : journal of the International Society for
Matrix Biology, Germany},
Volume = {25},
Number = {3},
Pages = {175-84},
Year = {2006},
Month = {April},
ISSN = {0945-053X},
Keywords = {Elasticity • Fibronectins • Green Fluorescent
Proteins • Models, Molecular • Protein
Conformation* • Protein Folding • Protein
Structure, Tertiary • Recombinant Proteins •
Spectrum Analysis • Stress, Mechanical • chemistry
• chemistry* • genetics • metabolism •
methods},
Abstract = {While it is well established that fibronectin (FN) matrix
fibrils are elastic, the mechanism of fibril elasticity
during extension is still debated. To investigate the
molecular origin of FN fibril elasticity, we used single
molecule force spectroscopy (SMFS) to determine the
unfolding behavior of a recombinant FN-III protein construct
that contained eight FN-III domains ((1-8)FN-III) and two
green fluorescent protein (GFP) domains. FN-III domains were
distinguished from GFP domains by their shorter unfolding
lengths. The unfolding strengths of both domains were
determined for a wide range of pulling rates (50 to 1,745
nm/s). We found that the mechanical stabilities of FN-III
and GFP domains were very similar to each other over the
entire range of pulling speeds. FN fibrils containing GFP
remain brightly fluorescent, even when stretched, meaning
that GFP domains remain largely folded. Since GFP and FN-III
have equal unfolding strengths, this suggests that FN-III
domains are not extensively unraveled in stretched FN
fibrils. Our results thus favor an alternative model, which
invokes a conformational change from a compact to an
extended conformation, as the basis for FN fibril
elasticity.},
Key = {fds113229}
}
@article{fds113232,
Author = {M Osawa and HP Erickson},
Title = {Probing the domain structure of FtsZ by random truncation
and insertion of GFP.},
Journal = {Microbiology (Reading, England)},
Volume = {151},
Number = {Pt 12},
Pages = {4033-43},
Year = {2005},
Month = {December},
ISSN = {1350-0872},
url = {http://dx.doi.org/10.1099/mic.0.28219-0},
Keywords = {Bacterial Proteins • Cytoskeletal Proteins • DNA
Transposable Elements • Escherichia coli •
Escherichia coli Proteins • Gene Deletion • Green
Fluorescent Proteins • Macromolecular Substances •
Mutagenesis, Site-Directed • Recombinant Fusion
Proteins • analysis • biosynthesis •
chemistry • chemistry* • genetics •
metabolism},
Abstract = {Random transposon-mediated mutagenesis has been used to
create truncations and insertions of green fluorescent
protein (GFP), and Venus-yellow fluorescent protein (YFP),
in Escherichia coli FtsZ. Sixteen unique insertions were
obtained, and one of them, in the poorly conserved
C-terminal spacer, was functional for cell division with the
Venus-YFP insert. The insertion of enhanced GFP (eGFP) at
this same site was not functional; Venus-YFP was found to be
superior to eGFP in other respects too. Testing the
constructs for dominant negative effects led to the
following general conclusion. The N-terminal domain, aa
1-195, is an independently folding domain that can poison
Z-ring function when expressed without a functional
C-terminal domain. The effects were weak, requiring
expression of the mutant at 3-5 times the level of wild-type
FtsZ. The C-terminal domain, aa 195-383, was also
independently folding, but had no activity in vivo. The
differential activity of the N- and C-terminal domains
suggests that FtsZ protofilament assembly is directional,
with subunits adding primarily at the bottom of the
protofilament. Directional assembly could occur by either a
treadmilling or a dynamic instability mechanism.},
Language = {eng},
Doi = {10.1099/mic.0.28219-0},
Key = {fds113232}
}
@article{fds113230,
Author = {T Ohashi and HP Erickson},
Title = {Domain unfolding plays a role in superfibronectin
formation.},
Journal = {The Journal of biological chemistry},
Volume = {280},
Number = {47},
Pages = {39143-51},
Year = {2005},
Month = {November},
ISSN = {0021-9258},
url = {http://dx.doi.org/10.1074/jbc.M509082200},
Keywords = {Amino Acid Sequence • Animals • Bacterial Proteins
• Binding Sites • Cattle • Fibronectins
• Kinetics • Luminescent Proteins • Models,
Molecular • Molecular Sequence Data • Multiprotein
Complexes • Mutagenesis, Site-Directed • Peptide
Fragments • Protein Conformation • Protein Folding
• Protein Structure, Tertiary • Recombinant Fusion
Proteins • Transfection • biosynthesis •
biosynthesis* • chemistry • chemistry* •
genetics},
Abstract = {Superfibronectin (sFN) is a fibronectin (FN) aggregate that
is formed by mixing FN with anastellin, a fragment of the
first type III domain of FN. However, the mechanism of this
aggregation has not been clear. In this study, we found that
anastellin co-precipitated with FN in a ratio of
approximately 4:1, anastellin:FN monomer. The primary
binding site for anastellin was in the segment (III)1-3,
which bound three molecules of anastellin and was able to
form a precipitate without the rest of the FN molecule.
Anastellin binding to (III)3 caused a conformational change
in that domain that exposed a cryptic thermolysin-sensitive
site. An additional anastellin binds to (III)11, where it
enhances thermolysin digestion of (III)11. An engineered
disulfide bond in (III)3 inhibited both aggregation and
protease digestion, suggesting that the stability of (III)3
is a key factor in sFN formation. We propose a three-step
model for sFN formation: 1) FN-III domains spontaneously
unfold and refold; 2) anastellin binds to an unfolded
domain, preventing its refolding and leaving it with exposed
hydrophobic surfaces and beta-sheet edges; and 3) these
exposed elements bind to similar exposed elements on other
molecules, leading to aggregation. The model is consistent
with our observation that the kinetics of aggregation are
first order, with a reaction time of 500-700 s. Similar
mechanisms may contribute to the assembly of the native FN
matrix.},
Language = {eng},
Doi = {10.1074/jbc.M509082200},
Key = {fds113230}
}
@article{fds113225,
Author = {Y Chen and HP Erickson},
Title = {Rapid in vitro assembly dynamics and subunit turnover of
FtsZ demonstrated by fluorescence resonance energy
transfer.},
Journal = {The Journal of biological chemistry},
Volume = {280},
Number = {23},
Pages = {22549-54},
Year = {2005},
Month = {June},
ISSN = {0021-9258},
url = {http://dx.doi.org/10.1074/jbc.M500895200},
Keywords = {Biochemistry • Cysteine • Escherichia coli
Proteins • Fluorescein • Fluorescence Resonance
Energy Transfer • Guanosine Diphosphate •
Guanosine Triphosphate • Kinetics • Magnesium
• Microscopy, Electron • Microtubules •
Models, Chemical • Mutation • Polymers •
Protein Binding • Rhodamines • Time Factors •
chemistry • metabolism • methods* •
pharmacology • physiology*},
Abstract = {We have developed an assay for the assembly of FtsZ based on
fluorescence resonance energy transfer (FRET). We mutated an
innocuous surface residue to cysteine and labeled separate
pools with fluorescein (donor) and tetramethylrhodamine
(acceptor). When the pools were mixed and GTP was added,
assembly produced a FRET signal that was linearly
proportional to FtsZ concentration from 0.7 microm (the
critical concentration (C(c))) to 3 microm. At
concentrations greater than 3 microm, an enhanced FRET
signal was observed with both GTP and GDP, indicating
additional assembly above this second C(c). This second C(c)
varied with Mg(2+) concentration, whereas the 0.7 microm
C(c) did not. We used the FRET assay to measure the kinetics
of initial assembly by stopped flow. The data were fit by
the simple kinetic model used previously: monomer
activation, a weak dimer nucleus, and elongation, although
with some differences in kinetic parameters from the L68W
mutant. We then studied the rate of turnover at steady state
by pre-assembling separate pools of donor and acceptor
protofilaments. When the pools were mixed, a FRET signal
developed with a half-time of 7 s, demonstrating a rapid and
continuous disassembly and reassembly of protofilaments at
steady state. This is comparable with the 9-s half-time for
FtsZ turnover in vivo and the 8-s turnover time of GTP
hydrolysis in vitro. Finally, we found that an excess of GDP
caused disassembly of protofilaments with a half-time of 5
s. Our new data suggest that GDP does not exchange into
intact protofilaments. Rather, our interpretation is that
subunits are released following GTP hydrolysis, and then
they exchange GDP for GTP and reassemble into new
protofilaments, all on a time scale of 7 s. The mechanism
may be related to the dynamic instability of
microtubules.},
Language = {eng},
Doi = {10.1074/jbc.M500895200},
Key = {fds113225}
}
@article{fds113227,
Author = {CA Sontag and JT Staley and HP Erickson},
Title = {In vitro assembly and GTP hydrolysis by bacterial tubulins
BtubA and BtubB.},
Journal = {The Journal of cell biology},
Volume = {169},
Number = {2},
Pages = {233-8},
Year = {2005},
Month = {April},
ISSN = {0021-9525},
url = {http://dx.doi.org/10.1083/jcb.200410027},
Keywords = {Bacterial Proteins • Gram-Negative Bacteria •
Guanosine Triphosphate • Hydrolysis • Multiprotein
Complexes • Tubulin • chemistry* •
ultrastructure},
Abstract = {Arecent study identified genuine tubulin proteins, BtubA and
BtubB, in the bacterial genus Prosthecobacter. We have
expressed BtubA and BtubB in Escherichia coli and studied
their in vitro assembly. BtubB by itself formed rings with
an outer diameter of 35-36 nm in the presence of GTP or GDP.
Mixtures of BtubB and BtubA formed long protofilament
bundles, 4-7 protofilaments wide (20-30 protofilaments in
the three-dimensional bundle). Regardless of the starting
stoichiometry, the polymers always contained equal
concentrations of BtubA and BtubB, suggesting that BtubA and
B alternate along the protofilament. BtubA showed negligible
GTP hydrolysis, whereas BtubB hydrolyzed 0.40 mol GTP per
min per mol BtubB. This GTPase activity increased to 1.37
per min when mixed 1:1 with BtubA. A critical concentration
of 0.4-1.0 microM was indicated by light scattering
experiments and extrapolation of GTPase versus
concentration, thus suggesting a cooperative assembly
mechanism.},
Language = {eng},
Doi = {10.1083/jcb.200410027},
Key = {fds113227}
}
@article{fds113224,
Author = {SD Redick and J Stricker and G Briscoe and HP Erickson},
Title = {Mutants of FtsZ targeting the protofilament interface:
effects on cell division and GTPase activity.},
Journal = {Journal of bacteriology},
Volume = {187},
Number = {8},
Pages = {2727-36},
Year = {2005},
Month = {April},
ISSN = {0021-9193},
url = {http://dx.doi.org/10.1128/JB.187.8.2727-2736.2005},
Keywords = {Bacterial Proteins • Cell Division • Cytoskeletal
Proteins • GTP Phosphohydrolases • GTP-Binding
Proteins • Models, Biological • Mutation* •
Protein Conformation • chemistry • genetics •
metabolism • metabolism* • physiology •
physiology*},
Abstract = {The bacterial cell division protein FtsZ assembles into
straight protofilaments, one subunit thick, in which
subunits appear to be connected by identical bonds or
interfaces. These bonds involve the top surface of one
subunit making extensive contact with the bottom surface of
the subunit above it. We have investigated this interface by
site-directed mutagenesis. We found nine bottom and eight
top mutants that were unable to function for cell division.
We had expected that some of the mutants might poison cell
division substoichiometrically, but this was not found for
any mutant. Eight of the bottom mutants exhibited dominant
negative effects (reduced colony size) and four completely
blocked colony formation, but this required expression of
the mutant protein at four to five times the wild-type FtsZ
level. Remarkably, the top mutants were even weaker, most
showing no effect at the highest expression level. This
suggests a directional assembly or treadmilling, where
subunit addition is primarily to the bottom end of the
protofilament. Selected pairs of top and bottom mutants
showed no GTPase activity up to 10 to 20 microM, in contrast
to the high GTPase activity of wild-type FtsZ above 1 muM.
Overall, these results suggest that in order for a subunit
to bind a protofilament at the 1 microM K(d) for elongation,
it must have functional interfaces at both the top and
bottom. This is inconsistent with the present model of the
protofilament, as a simple stack of subunits one on top of
the other, and may require a new structural
model.},
Language = {eng},
Doi = {10.1128/JB.187.8.2727-2736.2005},
Key = {fds113224}
}
@article{fds113226,
Author = {Y Chen and K Bjornson and SD Redick and HP Erickson},
Title = {A rapid fluorescence assay for FtsZ assembly indicates
cooperative assembly with a dimer nucleus.},
Journal = {Biophysical journal},
Volume = {88},
Number = {1},
Pages = {505-14},
Year = {2005},
Month = {January},
ISSN = {0006-3495},
url = {http://dx.doi.org/10.1529/biophysj.104.044149},
Keywords = {Actins • Bacterial Proteins • Biophysics •
Buffers • Cell Division • Cytoskeletal Proteins
• Cytoskeleton • Dimerization • Dose-Response
Relationship, Drug • Edetic Acid • Escherichia
coli • Guanosine Triphosphate • Hydrogen-Ion
Concentration • Hydrolysis • Kinetics • Light
• Models, Chemical • Mutation • Polymers
• Scattering, Radiation • Spectrometry,
Fluorescence • Time Factors • Tryptophan •
analysis • chemistry • chemistry* •
metabolism • methods*},
Abstract = {FtsZ is the major cytoskeletal protein operating in
bacterial cell division. FtsZ assembles into protofilaments
in vitro, and there has been some controversy over whether
the assembly is isodesmic or cooperative. Assembly has been
assayed previously by sedimentation and light scattering.
However, these techniques will under-report small polymers.
We have now produced a mutant of Escherichia coli FtsZ,
L68W, which gives a 250% increase in tryptophan fluorescence
upon polymerization. This provides a real-time assay of
polymer that is directly proportional to the concentration
of subunit interfaces. FtsZ-L68W is functional for cell
division, and should therefore be a valid model for studying
the thermodynamics and kinetics of FtsZ assembly. We assayed
assembly at pH 7.7 and pH 6.5, in 2.5 mM EDTA. EDTA blocks
GTP hydrolysis and should give an assembly reaction that is
not complicated by the irreversible hydrolysis step.
Assembly kinetics was determined with a stopped-flow device
for a range of FtsZ concentrations. When assembly was
initiated by adding 0.2 mM GTP, fluorescence increase showed
a lag, followed by nucleation, elongation, and a plateau.
The assembly curves were fit to a cooperative mechanism that
included a monomer activation step, a weak dimer nucleus,
and elongation. Fragmentation was absent in the model,
another characteristic of cooperative assembly. We are left
with an enigma: how can the FtsZ protofilament, which
appears to be one-subunit thick, assemble with apparent
cooperativity?},
Language = {eng},
Doi = {10.1529/biophysj.104.044149},
Key = {fds113226}
}
@article{fds113223,
Author = {DE Anderson and FJ Gueiros-Filho and HP Erickson},
Title = {Assembly dynamics of FtsZ rings in Bacillus subtilis and
Escherichia coli and effects of FtsZ-regulating
proteins.},
Journal = {Journal of bacteriology},
Volume = {186},
Number = {17},
Pages = {5775-81},
Year = {2004},
Month = {September},
ISSN = {0021-9193},
url = {http://dx.doi.org/10.1128/JB.186.17.5775-5781.2004},
Keywords = {Adenosine Triphosphatases • Artificial Gene Fusion
• Bacillus subtilis • Bacterial Proteins •
Cell Division • Cytoskeletal Proteins •
Escherichia coli • Escherichia coli Proteins •
Fluorescence • GTP Phosphohydrolases • Gene
Deletion • Genes, Bacterial • Genes, Reporter
• Green Fluorescent Proteins • Guanosine
Triphosphate • Half-Life • Luminescent Proteins
• Membrane Proteins • Mutation • analysis
• genetics • metabolism • metabolism* •
physiology},
Abstract = {FtsZ is the major cytoskeletal component of the bacterial
cell division machinery. It forms a ring-shaped structure
(the Z ring) that constricts as the bacterium divides.
Previous in vivo experiments with green fluorescent
protein-labeled FtsZ and fluorescence recovery after
photobleaching have shown that the Escherichia coli Z ring
is extremely dynamic, continually remodeling itself with a
half time of 30 s, similar to microtubules in the mitotic
spindle. In the present work, under different experimental
conditions, we have found that the half time for
fluorescence recovery of E. coli Z rings is even shorter
(approximately 9 s). As before, the turnover appears to be
coupled to GTP hydrolysis, since the mutant FtsZ84 protein,
with reduced GTPase in vitro, showed an approximately 3-fold
longer half time. We have also extended the studies to
Bacillus subtilis and found that this species exhibits
equally rapid dynamics of the Z ring (half time,
approximately 8 s). Interestingly, null mutations of the
FtsZ-regulating proteins ZapA, EzrA, and MinCD had only
modest effects on the assembly dynamics. This suggests that
these proteins do not directly regulate FtsZ subunit
exchange in and out of polymers. In B. subtilis, only 30 to
35% of the FtsZ protein was in the Z ring, from which we
conclude that a Z ring only 2 or 3 protofilaments thick can
function for cell division.},
Language = {eng},
Doi = {10.1128/JB.186.17.5775-5781.2004},
Key = {fds113223}
}
@article{fds113117,
Author = {KC Ingham and SA Brew and HP Erickson},
Title = {Localization of a cryptic binding site for tenascin on
fibronectin.},
Journal = {The Journal of biological chemistry, United
States},
Volume = {279},
Number = {27},
Pages = {28132-5},
Year = {2004},
Month = {July},
ISSN = {0021-9258},
Keywords = {Animals • Binding Sites • Cell Division •
Dimerization • Extracellular Matrix • Fibronectins
• Kinetics • Models, Genetic • Protein
Binding • Protein Conformation • Protein Folding
• Protein Structure, Tertiary • Spectrophotometry
• Surface Plasmon Resonance • Swine •
Temperature • Tenascin • Time Factors •
chemistry* • metabolism},
Abstract = {Fibronectin and tenascin are large extracellular matrix
proteins that interact with each other and with integrin
receptors to regulate cell growth and movement. They are
both modular proteins composed of independently folded
domains (modules) that are arranged in linear fashion.
Fibronectin is a covalent dimer and tenascin is a hexamer.
The site on tenascin to which fibronectin binds has been
localized to type III modules 3-5. In this study we use
surface plasmon resonance to examine the interaction between
various fragments of fibronectin and tenascin to further
characterize and localize the binding sites. We found that
tenascin fragments that contain type III modules 3-5 bind
primarily to the N-terminal 29-kDa hep-1/fib-1 domain, which
contains the first five type I modules of fibronectin. The
dissociation constant, K(d), is approximately 1 microm. The
binding site on fibronectin appears to be cryptic in the
whole molecule in solution but is exposed on the proteolytic
fragments and probably when fibronectin is in the extended
conformation.},
Key = {fds113117}
}
@article{fds113165,
Author = {T Ohashi and HP Erickson},
Title = {The disulfide bonding pattern in ficolin
multimers.},
Journal = {The Journal of biological chemistry},
Volume = {279},
Number = {8},
Pages = {6534-9},
Year = {2004},
Month = {February},
ISSN = {0021-9258},
url = {http://dx.doi.org/10.1074/jbc.M310555200},
Keywords = {Amino Acid Sequence • Animals • Blotting, Western
• CHO Cells • Carrier Proteins •
Chromatography, Affinity • Cricetinae • Culture
Media, Conditioned • Cysteine • Dimerization
• Disulfides • Electrophoresis, Polyacrylamide Gel
• Glycerol • Lectins* • Microscopy, Electron
• Models, Molecular • Molecular Sequence Data
• Mutation • Oxygen • Protein Conformation
• Protein Structure, Tertiary • Recombinant
Proteins • Sequence Homology, Amino Acid • Trypsin
• chemistry • chemistry* • metabolism •
pharmacology},
Abstract = {Ficolin is a plasma lectin, consisting of a short N-terminal
multimerization domain, a middle collagen domain, and a
C-terminal fibrinogen-like domain. The collagen domains
assemble the subunits into trimers, and the N-terminal
domain assembles four trimers into 12-mers. Two cysteine
residues in the N-terminal domain are thought to mediate
multimerization by disulfide bonding. We have generated
three mutants of ficolin alpha in which the N-terminal
cysteines were substituted by serines (Cys4, Cys24, and
Cys4/Cys24). The N-terminal cysteine mutants were produced
in a mammalian cell expression system, purified by affinity
chromatography, and analyzed under nondenaturing conditions
to resolve the multimer structure of the native protein and
under denaturing conditions to resolve the disulfide-linked
structure. Glycerol gradient sedimentation and electron
microscopy in nondenaturing conditions showed that plasma
and recombinant wild-type protein formed 12-mers. The Cys4
mutant also formed 12-mers, but Cys24 and Cys4/Cys24 mutants
formed only trimers. This means that protein interfaces
containing Cys4 are stable as noncovalent protein-protein
interactions and do not require disulfides, whereas those
containing Cys24-Cys24 require the disulfides for stability.
Proteins were also analyzed by nonreducing SDS-PAGE to show
the covalent structure under denaturing conditions.
Wild-type ficolin was covalently linked into 12-mers,
whereas elimination of either Cys4 or Cys24 gave dimers and
monomers. We present a model in which symmetric Cys24-Cys24
disulfide bonds between trimers are the basis for
multimerization. The model may also be relevant to collectin
multimers.},
Language = {eng},
Doi = {10.1074/jbc.M310555200},
Key = {fds113165}
}
@article{fds113135,
Author = {J Stricker and HP Erickson},
Title = {In vivo characterization of Escherichia coli ftsZ mutants:
effects on Z-ring structure and function.},
Journal = {Journal of bacteriology},
Volume = {185},
Number = {16},
Pages = {4796-805},
Year = {2003},
Month = {August},
ISSN = {0021-9193},
Keywords = {Bacterial Proteins • Cell Division • Culture Media
• Cytoskeletal Proteins* • Escherichia coli •
Genetic Complementation Test • Microscopy, Fluorescence
• Mutation* • cytology* • genetics •
growth & development • metabolism* •
ultrastructure*},
Abstract = {We have characterized the in vivo phenotypes of 17 mutations
of Escherichia coli ftsZ. In particular, we determined
whether these mutations can complement a null ftsZ
phenotype, and we demonstrated that two noncomplementing
mutations show partial dominant-negative behavior. We
performed immunofluorescence microscopy to determine whether
these mutants could assemble into normal or abnormal
structures in vivo. The mutants separated into four
classes-those that complemented the null and formed normal
FtsZ rings, those that complemented the null but formed
aberrant FtsZ structures, those that formed aberrant FtsZ
structures and did not complement, and those that were
unable to form any FtsZ structures. We did not find any
mutations that produced nonfunctional Z rings of normal
appearance. Surprisingly, some mutants that produced
extensively spiraled Z-ring structures divided and grew with
a normal doubling time. The analysis was carried out using a
complementation system based on an ftsZ deletion strain, a
temperature-sensitive rescue plasmid, and a complementation
vector that placed mutated ftsZ alleles under the control of
the pBAD promoter, which offered several advantages over
previous systems.},
Language = {eng},
Key = {fds113135}
}
@article{fds113203,
Author = {MR Caplan and HP Erickson},
Title = {Apparent cooperative assembly of the bacterial cell division
protein FtsZ demonstrated by isothermal titration
calorimetry.},
Journal = {The Journal of biological chemistry, United
States},
Volume = {278},
Number = {16},
Pages = {13784-8},
Year = {2003},
Month = {April},
ISSN = {0021-9258},
Keywords = {Bacterial Proteins • Biochemistry • Calorimetry
• Cell Division • Cytoskeletal Proteins* •
Dimerization • Escherichia coli • Guanosine
Diphosphate • Guanosine Triphosphate • Magnesium
• Microscopy, Electron • Thermodynamics •
Time Factors • chemistry* • metabolism •
metabolism* • methods • pharmacology},
Abstract = {The assembly dynamics of FtsZ, a prokaryotic homolog of
tubulin, are important for their role in bacterial
cytokinesis. Here we used isothermal titration calorimetry
(ITC) to measure the heat of FtsZ self-association under
various conditions. The measurements were designed to test
whether FtsZ protofilaments are assembled by an isodesmic
(linear aggregates in which each bond has an identical
equilibrium constant) or a cooperative (aggregates only
become stable after forming a oligomeric nucleus) assembly
process. The isodesmic model can fit the assembly in GDP
closely but cannot fit the assembly in GTP. FtsZ-GTP without
Mg(2+) exhibits an apparent critical concentration, which is
indicative of cooperative assembly, near 2.9 microm. With
2.5 mm Mg(2+) (which allows FtsZ to hydrolyze GTP) the
critical concentration is reduced 10-fold to approximately
0.31 microm. Both with and without Mg(2+) there is no
evidence for assembly below the critical concentration, but
there is an abrupt transition to full assembly above. The
ITC data are highly suggestive of a cooperative assembly,
although this is difficult to reconcile with the
1-subunit-thick protofilaments observed by electron
microscopy.},
Key = {fds113203}
}
@article{fds113177,
Author = {F Li and SD Redick and HP Erickson and VT Moy},
Title = {Force measurements of the alpha5beta1 integrin-fibronectin
interaction.},
Journal = {Biophysical journal, United States},
Volume = {84},
Number = {2 Pt 1},
Pages = {1252-62},
Year = {2003},
Month = {February},
ISSN = {0006-3495},
Keywords = {Elasticity • Fibronectins • Humans • Integrin
alpha4beta1 • K562 Cells • Macromolecular
Substances • Micromanipulation • Microscopy,
Atomic Force • Models, Chemical • Motion •
Protein Binding • Recombinant Proteins • Stress,
Mechanical • Tensile Strength • Weight-Bearing
• chemistry • chemistry* • metabolism •
methods • methods*},
Abstract = {The interaction of the alpha(5)beta(1) integrin and its
ligand, fibronectin (FN), plays a crucial role in the
adhesion of cells to the extracellular matrix. An important
intrinsic property of the alpha(5)beta(1)/FN interaction is
the dynamic response of the complex to a pulling force. We
have carried out atomic force microscopy measurements of the
interaction between alpha(5)beta(1) and a fibronectin
fragment derived from the seventh through tenth type III
repeats of FN (i.e., FN7-10) containing both the arg-gly-asp
(RGD) sequence and the synergy site. Direct force
measurements obtained from an experimental system consisting
of an alpha(5)beta(1) expressing K562 cell attached to the
atomic force microscopy cantilever and FN7-10 adsorbed on a
substrate were used to determine the dynamic response of the
alpha(5)beta(1)/FN7-10 complex to a pulling force. The
experiments were carried out over a three-orders-of-magnitude
change in loading rate and under conditions that allowed for
detection of individual alpha(5)beta(1)/FN7-10 interactions.
The dynamic rupture force of the alpha(5)beta(1)/FN7-10
complex revealed two regimes of loading: a fast loading
regime (>10,000 pN/s) and a slow loading regime (<10,000
pN/s) that characterize the inner and outer activation
barriers of the complex, respectively. Activation by TS2/16
antibody increased both the frequency of adhesion and
elevated the rupture force of the alpha(5)beta(1)/wild type
FN7-10 complex to higher values in the slow loading regime.
In experiments carried out with a FN7-10 RGD deleted mutant,
the force measurements revealed that both inner and outer
activation barriers were suppressed by the mutation.
Mutations to the synergy site of FN, however, suppressed
only the outer barrier activation of the complex. For both
the RGD and synergy deletions, the frequency of adhesion was
less than that of the wild type FN7-10, but was increased by
integrin activation. The rupture force of these mutants was
only slightly less than that of the wild type, and was not
increased by activation. These results suggest that integrin
activation involved a cooperative interaction with both the
RGD and synergy sites.},
Key = {fds113177}
}
@article{fds113090,
Author = {T Ohashi and CA Hale and PA de Boer and HP Erickson},
Title = {Structural evidence that the P/Q domain of ZipA is an
unstructured, flexible tether between the membrane and the
C-terminal FtsZ-binding domain.},
Journal = {Journal of bacteriology, United States},
Volume = {184},
Number = {15},
Pages = {4313-5},
Year = {2002},
Month = {August},
ISSN = {0021-9193},
Keywords = {Bacterial Proteins • Carrier Proteins • Cell Cycle
Proteins • Cell Division • Cytoskeletal Proteins*
• Escherichia coli • Escherichia coli Proteins*
• Glutamine • Green Fluorescent Proteins •
Luminescent Proteins • Microscopy, Electron •
Models, Molecular • Proline • Protein Binding
• Protein Conformation • chemistry •
chemistry* • ultrastructure},
Abstract = {The cell division protein ZipA has an N-terminal
transmembrane domain and a C-terminal globular domain that
binds FtsZ. Between them are a charged domain and a P/Q
domain rich in proline and glutamine that has been proposed
to be an unfolded polypeptide. Here we provide evidence
obtained by electron microscopy that the P/Q domain is a
flexible tether ranging in length from 8 to 20 nm and
invisible in rotary shadowing electron microscopy. We
estimated a persistence length of 0.66 nm, which is similar
to the persistence lengths of other unfolded and
unstructured polypeptides.},
Key = {fds113090}
}
@article{fds113143,
Author = {MA Ghert and WN Qi and HP Erickson and JA Block and SP
Scully},
Title = {Tenascin-C expression and distribution in cultured human
chondrocytes and chondrosarcoma cells.},
Journal = {Journal of orthopaedic research : official publication of
the Orthopaedic Research Society, United
States},
Volume = {20},
Number = {4},
Pages = {834-41},
Year = {2002},
Month = {July},
ISSN = {0736-0266},
Keywords = {Blotting, Western • Bone Neoplasms • Cells,
Cultured • Chondrocytes • Chondrosarcoma •
Humans • Immunohistochemistry • Polymerase Chain
Reaction • Protein Isoforms • Tenascin •
analysis* • chemistry* • genetics •
metabolism},
Abstract = {Tenascin-C (TNC) is an oligomeric glycoprotein of the
extracellular matrix with several distinct isoforms variably
expressed during embryogenesis, tumorogenesis, angiogenesis
and wound healing. In the normal human adult, TNC is found
in large concentrations in articular cartilage, suggesting
tissue-specific function. The purpose of this study was to
determine the specific in vitro TNC splicing patterns of
articular chondrocytes and a human chondrosarcoma cell line.
Cells were cultured in a three-dimensional bead system and
TNC splice variant expression and distribution were examined
with the use of Western blotting techniques,
semi-quantitative reverse-transcription polymerase chain
reaction and immunohistochemistry. At both the
transcriptional and post-translational levels, the
chondrocytes were found to express significantly higher
levels of the smaller 220 kDa isoform (P < 0.01), which was
predominantly incorporated into the matrix. The splicing
pattern of the malignant cells was characterized by a higher
proportion of the larger 320 kDa isoform which was extruded
into the media. In vivo studies are necessary to verify the
expression of the large TNC isoform in chondrosarcoma and
the production and integration of the smaller isoform in
normal chondroid matrix. In addition, elucidation of the
biologic functions of the two major TNC isoforms may lead to
the development of novel diagnostic and therapeutic
approaches to chondrosarcoma.},
Key = {fds113143}
}
@article{fds113196,
Author = {F Coussen and D Choquet and MP Sheetz and HP Erickson},
Title = {Trimers of the fibronectin cell adhesion domain localize to
actin filament bundles and undergo rearward
translocation.},
Journal = {Journal of cell science, England},
Volume = {115},
Number = {Pt 12},
Pages = {2581-90},
Year = {2002},
Month = {June},
ISSN = {0021-9533},
Keywords = {3T3 Cells • Animals • Cell Adhesion • Cell
Membrane • Eukaryotic Cells • Extracellular Matrix
• Fibronectins • Integrin alpha5beta1 •
Integrins • Mice • Microfilaments •
Microspheres • Peptide Fragments • Polymers •
Protein Binding • Protein Structure, Tertiary •
Protein Transport • chemistry • cytology •
diagnostic use • metabolism • metabolism* •
physiology • physiology* • ultrastructure},
Abstract = {Previous studies have shown that small beads coated with
FN7-10, a four-domain cell adhesion fragment of fibronectin,
bind to cell surfaces and translocate rearward. Here we
investigate whether soluble constructs containing two to
five FN7-10 units might be sufficient for activity. We have
produced a monomer, three forms of dimers, a trimer and a
pentamer of FN7-10, on the end of spacer arms. These
oligomers could bind small clusters of up to five integrins.
Fluorescence microscopy showed that the trimer and pentamer
bound strongly to the cell surface, and within 5 minutes
were prominently localized to actin fiber bundles. Monomers
and dimers showed only diffuse localization. Beads coated
with a low concentration (probably one complex per bead) of
trimer or pentamer showed prolonged binding and rearward
translocation, presumably with the translocating actin
cytskeleton. Beads containing monomer or dimer showed only
brief binding and diffusive movements. We conclude that
clusters of three integrin-binding ligands are necessary and
sufficient for coupling to and translocating with the actin
cytoskeleton.},
Key = {fds113196}
}
@article{fds113155,
Author = {J Takagi and DP DeBottis and HP Erickson and TA Springer},
Title = {The role of the specificity-determining loop of the integrin
beta subunit I-like domain in autonomous expression,
association with the alpha subunit, and ligand
binding.},
Journal = {Biochemistry, United States},
Volume = {41},
Number = {13},
Pages = {4339-47},
Year = {2002},
Month = {April},
ISSN = {0006-2960},
Keywords = {Amino Acid Sequence • Animals • Antibodies,
Monoclonal • Antigens, CD18 • Antigens, CD29
• Cell Adhesion • Cell Line • Dimerization
• Electrophoresis, Polyacrylamide Gel • Epitopes
• Fibronectins • Gene Deletion • Humans
• Ligands • Mice • Models, Molecular •
Molecular Sequence Data • Mutation • Precipitin
Tests • Protein Binding • Protein Folding •
Protein Structure, Secondary • Protein Structure,
Tertiary • Recombinant Proteins • Sequence
Homology, Amino Acid • Transfection • chemistry
• chemistry*},
Abstract = {Integrin beta subunits contain a highly conserved I-like
domain that is known to be important for ligand binding.
Unlike integrin I domains, the I-like domain requires
integrin alpha and beta subunit association for optimal
folding. Pactolus is a novel gene product that is highly
homologous to integrin beta subunits but lacks associating
alpha subunits [Chen, Y., Garrison, S., Weis, J. J., and
Weis, J. H. (1998) J. Biol. Chem. 273, 8711-8718] and a
approximately 30 amino acid segment corresponding to the
specificity-determining loop (SDL) in the I-like domain. We
find that the SDL is responsible for the defects in integrin
beta subunit expression and folding in the absence of alpha
subunits. When transfected in the absence of alpha subunits
into cells, extracellular domains of mutant beta subunits
lacking SDL, but not wild-type beta subunits, were well
secreted and contained immunoreactive I-like domains. The
purified recombinant soluble beta1 subunit with the SDL
deletion showed an elongated shape in electron microscopy,
consistent with its structure in alphabeta complexes. The
SDL segment is not required for formation of alpha5beta1,
alpha4beta1, alphaVbeta3, and alpha6beta4 heterodimers, but
is essential for fomation of alpha6beta1, alphaVbeta1, and
alphaLbeta2 heterodimers, suggesting that usage of subunit
interface residues is variable among integrins. The beta1
SDL is required for ligand binding and for the formation of
the epitope for the alpha5 monoclonal antibody 16 that maps
to loop segments connecting blades 2 and 3 of beta-propeller
domain of alpha5, but is not essential for nearby
beta-propeller epitopes.},
Key = {fds113155}
}
@article{fds113151,
Author = {T Ohashi and DP Kiehart and HP Erickson},
Title = {Dual labeling of the fibronectin matrix and actin
cytoskeleton with green fluorescent protein
variants.},
Journal = {Journal of cell science},
Volume = {115},
Number = {Pt 6},
Pages = {1221-9},
Year = {2002},
Month = {March},
ISSN = {0021-9533},
Keywords = {3T3 Cells • Actin Cytoskeleton • Actins •
Animals • Cell Movement • Cells, Cultured •
Cytochalasins • Extracellular Matrix •
Fibronectins • Genetic Vectors • Green Fluorescent
Proteins • Indicators and Reagents • Integrins
• Luminescent Proteins • Mice • Microfilament
Proteins • Recombinant Fusion Proteins • analysis
• analysis* • chemistry • genetics •
metabolism • pharmacology • physiology •
ultrastructure*},
Abstract = {We have prepared 3T3 cells doubly labeled to visualize
simultaneously the extracellular fibronectin (FN) matrix and
intracellular actin cytoskeleton in living cell cultures. We
used FN-yellow fluorescent protein (FN-yfp) for the FN
matrix, and the actin-binding domain of moesin fused to cyan
fluorescent protein (cfp-Moe) to stain actin. Actin filament
bundles were clearly seen in the protruding lamellae of the
cells. FN matrix assembly appeared to be initiated as small
spots of FN at the ends of actin filament bundles. The spots
then elongated along the actin filament bundle toward the
cell center to form FN fibrils. The end of the fibril
towards the cell edge appeared immobile, and probably
attached to the substrate, whereas the end toward the cell
center frequently showed movements, suggesting attachment to
the cell. Combining our data with the observations of Pankov
et al. we suggest that fibrils grow by stretching this
mobile end toward the cell center while adding new FN
molecules at the end and along the entire length. When the
cell culture was treated with cytochalasin to disrupt the
actin cytoskeleton, some fibrils contracted substantially,
suggesting that the segment attached primarily to the cell
surface is stretched.},
Language = {eng},
Key = {fds113151}
}
@article{fds113088,
Author = {J Stricker and P Maddox and ED Salmon and HP Erickson},
Title = {Rapid assembly dynamics of the Escherichia coli FtsZ-ring
demonstrated by fluorescence recovery after
photobleaching.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America},
Volume = {99},
Number = {5},
Pages = {3171-5},
Year = {2002},
Month = {March},
ISSN = {0027-8424},
url = {http://dx.doi.org/10.1073/pnas.052595099},
Keywords = {Bacterial Proteins • Carrier Proteins • Cell Cycle
Proteins • Cytoskeletal Proteins* • Escherichia
coli • Escherichia coli Proteins* • Fluorescence
• Green Fluorescent Proteins • Luminescent
Proteins • Recombinant Fusion Proteins • Time
Factors • genetics • metabolism •
metabolism*},
Abstract = {FtsZ, the major cytoskeletal component of the bacterial
cell-division machine, assembles into a ring (the Z-ring)
that contracts at septation. FtsZ is a bacterial homolog of
tubulin, with similar tertiary structure, GTP hydrolysis,
and in vitro assembly. We used green fluorescent
protein-labeled FtsZ and fluorescence recovery after
photobleaching to show that the E. coli Z-ring is extremely
dynamic, continually remodeling itself with a half-time of
30 s. ZipA, a membrane protein involved in cell division
that colocalizes with FtsZ, was equally dynamic. The Z-ring
of the mutant ftsZ84, which has 1/10 the guanosine
triphosphatase activity of wild-type FtsZ in vitro, showed a
9-fold slower turnover in vivo. This finding implies that
assembly dynamics are determined primarily by GTP
hydrolysis. Despite the greatly reduced assembly dynamics,
the ftsZ84 cells divide with a normal cell-cycle
time.},
Language = {eng},
Doi = {10.1073/pnas.052595099},
Key = {fds113088}
}
@article{fds113149,
Author = {DE Anderson and A Losada and HP Erickson and T Hirano},
Title = {Condensin and cohesin display different arm conformations
with characteristic hinge angles.},
Journal = {The Journal of cell biology, United States},
Volume = {156},
Number = {3},
Pages = {419-24},
Year = {2002},
Month = {February},
ISSN = {0021-9525},
Keywords = {Adenosine Triphosphatases • Adenosine Triphosphate
• Animals • Binding Sites • Cell Cycle
Proteins • Chromosomal Proteins, Non-Histone •
Chromosome Segregation • Chromosomes •
Chromosomes, Bacterial • DNA-Binding Proteins •
Fungal Proteins • Hela Cells • Humans •
Metaphase • Microscopy, Electron • Multiprotein
Complexes • Nuclear Proteins • Protein Folding
• Protein Structure, Tertiary • Xenopus Proteins
• chemistry • chemistry* • genetics •
metabolism • physiology • physiology* •
ultrastructure • ultrastructure*},
Abstract = {Structural maintenance of chromosomes (SMC) proteins play
central roles in higher-order chromosome dynamics from
bacteria to humans. In eukaryotes, two different SMC protein
complexes, condensin and cohesin, regulate chromosome
condensation and sister chromatid cohesion, respectively.
Each of the complexes consists of a heterodimeric pair of
SMC subunits and two or three non-SMC subunits. Previous
studies have shown that a bacterial SMC homodimer has a
symmetrical structure in which two long coiled-coil arms are
connected by a flexible hinge. A catalytic domain with DNA-
and ATP-binding activities is located at the distal end of
each arm. We report here the visualization of vertebrate
condensin and cohesin by electron microscopy. Both complexes
display the two-armed structure characteristic of SMC
proteins, but their conformations are remarkably different.
The hinge of condensin is closed and the coiled-coil arms
are placed close together. In contrast, the hinge of cohesin
is wide open and the coiled-coils are spread apart from each
other. The non-SMC subunits of both condensin and cohesin
form a globular complex bound to the catalytic domains of
the SMC heterodimers. We propose that the "closed"
conformation of condensin and the "open" conformation of
cohesin are important structural properties that contribute
to their specialized biochemical and physiological
functions.},
Key = {fds113149}
}
@article{fds113139,
Author = {HP Erickson},
Title = {Stretching fibronectin.},
Journal = {Journal of muscle research and cell motility},
Volume = {23},
Number = {5-6},
Pages = {575-80},
Year = {2002},
ISSN = {0142-4319},
Keywords = {Animals • Elasticity • Fibronectins •
Fluorescence Resonance Energy Transfer • Fluorescent
Dyes • Humans • Microscopy, Fluorescence •
Models, Molecular • Motion • Protein Conformation
• Protein Denaturation • chemistry •
diagnostic use • metabolism*},
Abstract = {Fibronectin (FN) matrix fibrils assembled in cell culture
have been observed to stretch in response to cell movements,
and when broken relax to 1/3 to 1/4 of their rest length.
Two molecular mechanisms have been proposed, for the
elasticity. One proposes that FN molecules in relaxed fibers
are bent and looped into a compact conformation, and
stretching pulls the molecules into the extended
conformation but domains remain folded. The second proposes
that molecules in fibrils are already extended, and
stretching is produced by force-induced unfolding of FN type
III domains. Experimental observations that may help
distinguish these two possibilities are discussed.},
Language = {eng},
Key = {fds113139}
}
@article{fds113116,
Author = {J Haspel and G Schürmann and J Jacob and HP Erickson and M
Grumet},
Title = {Disulfide-mediated dimerization of L1 Ig
domains.},
Journal = {Journal of neuroscience research, United
States},
Volume = {66},
Number = {3},
Pages = {347-55},
Year = {2001},
Month = {November},
ISSN = {0360-4012},
Keywords = {Binding Sites • Central Nervous System •
Dimerization • Disulfides • Green Fluorescent
Proteins • Immunoglobulins • Indicators and
Reagents • Leukocyte L1 Antigen Complex •
Luminescent Proteins • Membrane Glycoproteins •
Microscopy, Electron • Mutation • Nervous System
Malformations • Neural Cell Adhesion Molecules •
Protein Folding* • Protein Structure, Tertiary •
Recombinant Fusion Proteins • embryology •
etiology • genetics • growth & development •
metabolism • metabolism* • physiology •
physiopathology • ultrastructure •
ultrastructure*},
Abstract = {The neural cell adhesion molecule L1 contains
immunoglobulin-like (Ig) domains in its extracellular region
that mediate homophilic binding, neurite outgrowth and other
activities relevant to CNS development. To correlate
conformations of these domains to biological function,
several L1-Fc fusion proteins whose bioactivities were
previously characterized were analyzed by rotary shadowing
electron microscopy. We found that bioactive L1-Fcs
containing Ig domains 1-4 or 1-6 exhibited extended,
branched structures. In contrast, inactive L1-Fcs containing
only the first two or three Ig domains assumed compact
shapes that suggested interactions between the L1 arms of
these proteins. Analysis of an untagged L1 fragment composed
of Ig domains 1-3 demonstrated a mixture of monomeric and
dimeric forms. Surprisingly, these dimers were stabilized by
intermolecular disulfide bonds. Finally, cell surface L1-GFP
fusion proteins containing only the first two or three Ig
domains in the extracellular region also engaged in
disulfide-mediated dimerization. These results suggest a
novel mechanism by which mutations in L1 could interfere
with its biological functioning.},
Key = {fds113116}
}
@article{fds113162,
Author = {DE Anderson and KM Trujillo and P Sung and HP Erickson},
Title = {Structure of the Rad50 x Mre11 DNA repair complex from
Saccharomyces cerevisiae by electron microscopy.},
Journal = {The Journal of biological chemistry, United
States},
Volume = {276},
Number = {40},
Pages = {37027-33},
Year = {2001},
Month = {October},
ISSN = {0021-9258},
Keywords = {DNA • DNA Ligases • DNA Repair • DNA-Binding
Proteins* • Dimerization • Endodeoxyribonucleases*
• Exodeoxyribonucleases* • Fungal Proteins •
Microscopy, Electron • Protein Conformation •
Saccharomyces cerevisiae • Saccharomyces cerevisiae
Proteins* • chemistry • chemistry* •
metabolism},
Abstract = {The RAD50 gene of Saccharomyces cerevisiae is one of several
genes required for recombinational repair of double-strand
DNA breaks during vegetative growth and for initiation of
meiotic recombination. Rad50 forms a complex with two other
proteins, Mre11 and Xrs2, and this complex is involved in
double-strand break formation and processing. Rad50 has
limited sequence homology to the structural maintenance of
chromosomes (SMC) family of proteins and shares the same
domain structure as SMCs: N- and C-terminal globular domains
separated by two long coiled-coils. However, a notable
difference is the much smaller non-coil hinge region between
the two coiled-coils. We report here a structural analysis
of full-length S. cerevisiae Rad50, alone and in a complex
with yeast Mre11 by electron microscopy. Our results confirm
that yeast Rad50 does have the same antiparallel coiled-coil
structure as SMC proteins, but with no detectable globular
hinge domain. However, the molecule is still able to bend
sharply in the middle to bring the two catalytic domains
together, indicating that the small hinge domain is
flexible. We also demonstrate that Mre11 binds as a dimer
between the catalytic domains of Rad50, bringing the
nuclease activities of Mre11 in close proximity to the
ATPase and DNA binding activities of Rad50.},
Key = {fds113162}
}
@article{fds113124,
Author = {H Li and AF Oberhauser and SD Redick and M Carrion-Vazquez and HP
Erickson, JM Fernandez},
Title = {Multiple conformations of PEVK proteins detected by
single-molecule techniques.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America, United States},
Volume = {98},
Number = {19},
Pages = {10682-6},
Year = {2001},
Month = {September},
ISSN = {0027-8424},
Keywords = {Humans • Muscle Proteins • Peptides • Protein
Conformation • Protein Folding • Protein Kinases
• chemistry* • genetics},
Abstract = {An important component of muscle elasticity is the PEVK
region of titin, so named because of the preponderance of
these amino acids. However, the PEVK region, similar to
other elastomeric proteins, is thought to form a random coil
and therefore its structure cannot be determined by standard
techniques. Here we combine single-molecule electron
microscopy and atomic force microscopy to examine the
conformations of the human cardiac titin PEVK region. In
contrast to a simple random coil, we have found that cardiac
PEVK shows a wide range of elastic conformations with
end-to-end distances ranging from 9 to 24 nm and persistence
lengths from 0.4 to 2.5 nm. Individual PEVK molecules
retained their distinctive elastic conformations through
many stretch-relaxation cycles, consistent with the view
that these PEVK conformers cannot be interconverted by
force. The multiple elastic conformations of cardiac PEVK
may result from varying degrees of proline isomerization.
The single-molecule techniques demonstrated here may help
elucidate the conformation of other proteins that lack a
well-defined structure.},
Key = {fds113124}
}
@article{fds113150,
Author = {HP Erickson},
Title = {Cytoskeleton. Evolution in bacteria.},
Journal = {Nature, England},
Volume = {413},
Number = {6851},
Pages = {30},
Year = {2001},
Month = {September},
ISSN = {0028-0836},
Keywords = {Actins • Archaea • Bacillus subtilis •
Bacteria • Bacterial Proteins • Cytoskeleton
• Escherichia coli • Escherichia coli Proteins*
• Eukaryotic Cells • Evolution* • Evolution,
Molecular • Thermotoga maritima • chemistry •
genetics • genetics* • physiology*},
Key = {fds113150}
}
@article{fds113078,
Author = {L Cassimeris and D Gard and PT Tran and HP Erickson},
Title = {XMAP215 is a long thin molecule that does not increase
microtubule stiffness.},
Journal = {Journal of cell science, England},
Volume = {114},
Number = {Pt 16},
Pages = {3025-33},
Year = {2001},
Month = {August},
ISSN = {0021-9533},
Keywords = {Amino Acid Sequence • Animals • Biopolymers •
Dimerization • Microscopy, Electron •
Microtubule-Associated Proteins • Microtubules •
Molecular Conformation • Molecular Sequence Data •
Oocytes • Pliability • Protein Binding •
Protein Structure, Quaternary • Repetitive Sequences,
Amino Acid • Sequence Homology, Amino Acid •
Shadowing (Histology) • Tubulin • Xenopus •
Xenopus Proteins • chemistry • cytology •
metabolism • metabolism* • ultrastructure •
ultrastructure*},
Abstract = {XMAP215 is a microtubule associated protein that speeds
microtubule plus end growth by seven- to tenfold and
protects these ends from destabilization by the Kin I
kinesin, XKCM1. To understand the mechanisms responsible for
these activities, it is necessary to know the structure of
XMAP215. By unidirectional shadowing and electron
microscopy, XMAP215 appeared as an elongate molecule of
60+/-18 nm, suggesting that XMAP215 could span up to seven
to eight tubulin dimers along a protofilament. Most XMAP215
molecules were straight but a subset were bent suggesting
that XMAP215 is flexible. Antibodies to the C terminus
labeled one end of XMAP215 with no evidence for XMAP215
dimerization. Incubation of XMAP215 and tubulin at 4 degrees
C resulted in assembly of curved protofilaments, which
appeared to be incomplete tubulin rings. Measurements from
rotary shadowed samples showed that tubulin/XMAP215 partial
rings had an average width of 8.8+/-1.8 nm compared with
5.6+/-1.1 nm for rings assembled from tubulin dimers alone,
suggesting that XMAP215 adds a width of approximately 3.2 nm
to the curved tubulin protofilament. XMAP215 did not change
the radius of curvature of these partial tubulin rings.
Measurements of microtubule flexural rigidity by thermal
fluctuations showed that XMAP215 did not change microtubule
rigidity. Finally, sequence analysis shows that the
N-terminal half of XMAP215 contains four repeats, each
composed of multiple HEAT repeats.},
Key = {fds113078}
}
@article{fds113100,
Author = {CD Jun and CV Carman and SD Redick and M Shimaoka and HP Erickson and TA
Springer},
Title = {Ultrastructure and function of dimeric, soluble
intercellular adhesion molecule-1 (ICAM-1).},
Journal = {The Journal of biological chemistry, United
States},
Volume = {276},
Number = {31},
Pages = {29019-27},
Year = {2001},
Month = {August},
ISSN = {0021-9258},
Keywords = {Amino Acid Substitution • Animals • Binding Sites
• CHO Cells • Cell Line • Cricetinae •
Crystallography, X-Ray • Cysteine • DNA,
Complementary • Dimerization • Humans •
Intercellular Adhesion Molecule-1 • Lymphocyte
Function-Associated Antigen-1 • Microscopy, Electron
• Models, Molecular • Mutagenesis, Site-Directed
• Protein Conformation • Protein Structure,
Secondary • Recombinant Proteins • Surface Plasmon
Resonance • Surface Properties • Transfection
• chemistry • chemistry* • genetics •
physiology • ultrastructure • ultrastructure*},
Abstract = {Previous studies have demonstrated dimerization of
intercellular adhesion molecule-1 (ICAM-1) on the cell
surface and suggested a role for immunoglobulin superfamily
domain 5 and/or the transmembrane domain in mediating such
dimerization. Crystallization studies suggest that domain 1
may also mediate dimerization. ICAM-1 binds through domain 1
to the I domain of the integrin alpha(L)beta(2) (lymphocyte
function-associated antigen 1). Soluble C-terminally
dimerized ICAM-1 was made by replacing the transmembrane and
cytoplasmic domains with an alpha-helical coiled coil.
Electron microscopy revealed C-terminal dimers that were
straight, slightly bent, and sometimes U-shaped. A small
number of apparently closed ring-like dimers and W-shaped
tetramers were found. To capture ICAM-1 dimerized at the
crystallographically defined dimer interface in domain 1,
cysteines were introduced into this interface. Several of
these mutations resulted in the formation of soluble
disulfide-bonded ICAM-1 dimers (domain 1 dimers). Combining
a domain 1 cysteine mutation with the C-terminal dimers
(domain 1/C-terminal dimers) resulted in significant amounts
of both closed ring-like dimers and W-shaped tetramers.
Surface plasmon resonance studies showed that all of the
dimeric forms of ICAM-1 (domain 1, C-terminal, and domain
1/C-terminal dimers) bound similarly to the integrin
alpha(L)beta(2) I domain, with affinities approximately
1.5--3-fold greater than that of monomeric ICAM-1. These
studies demonstrate that ICAM-1 can form at least three
different topologies and that dimerization at domain 1 does
not interfere with binding in domain 1 to
alpha(L)beta(2).},
Key = {fds113100}
}
@article{fds113164,
Author = {M Hirano and DE Anderson and HP Erickson and T Hirano},
Title = {Bimodal activation of SMC ATPase by intra- and
inter-molecular interactions.},
Journal = {The EMBO journal, England},
Volume = {20},
Number = {12},
Pages = {3238-50},
Year = {2001},
Month = {June},
ISSN = {0261-4189},
Keywords = {Adenosine Triphosphatases • Adenosine Triphosphate
• Amino Acid Sequence • Animals • Bacillus
subtilis • Bacterial Proteins • DNA-Binding
Proteins • Enzyme Activation • Microscopy,
Electron • Molecular Sequence Data • Mutagenesis
• Nuclear Proteins • enzymology* • genetics
• metabolism • metabolism*},
Abstract = {Structural maintenance of chromosomes (SMC) proteins play
fundamental roles in higher-order chromosome dynamics from
bacteria to humans. It has been proposed that the Bacillus
subtilis SMC (BsSMC) homodimer is composed of two
anti-parallel coiled-coil arms, each having an ATP-binding
domain at its distal end. It remains totally unknown,
however, how the two-armed structure supports ATP-dependent
actions of BsSMC. By constructing a number of mutant
derivatives including 'single-armed' BsSMC, we show here
that the central hinge domain provides a structural
flexibility that allows opening and closing of the two arms.
This unique structure brings about bimodal regulation of the
SMC ATPase cycle. Closing the arm can trigger ATP hydrolysis
by allowing an end-end interaction within a dimer
(intramolecular mode). When bound to DNA, ATP promotes a
dimer-dimer interaction, which in turn activates their
DNA-dependent ATPase activity (intermolecular mode). Our
results reveal a novel mechanism of ATPase regulation and
provide mechanistic insights into how eukaryotic SMC protein
complexes could mediate diverse chromosomal functions, such
as chromosome condensation and sister chromatid
cohesion.},
Key = {fds113164}
}
@article{fds113184,
Author = {MA Ghert and WN Qi and HP Erickson and JA Block and SP
Scully},
Title = {Tenascin-C splice variant adhesive/anti-adhesive effects on
chondrosarcoma cell attachment to fibronectin.},
Journal = {Cell structure and function, Japan},
Volume = {26},
Number = {3},
Pages = {179-87},
Year = {2001},
Month = {June},
ISSN = {0386-7196},
Keywords = {Alternative Splicing • Binding Sites • Cell
Adhesion • Chondrosarcoma • Fibronectins •
Humans • Tenascin • Tumor Cells, Cultured •
genetics* • immunology • pathology* •
physiology*},
Abstract = {Tenascin-C is an oligomeric glycoprotein of the
extracellular matrix that has been found to have both
adhesive and anti-adhesive properties for cells. Recent
elucidation of the two major TNC splice variants (320 kDa
and 220 kDa) has shed light on the possibility of varying
functions of the molecule based on its splicing pattern.
Tenascin-C is prominently expressed in embryogenesis and in
pathologic conditions such as tumorogenesis and wound
healing. Fibronectin is a prominent adhesive molecule of the
extracellular matrix that is often co-localized with
tenascin-C in these processes. We studied the chondrosarcoma
cell line JJ012 with enzyme-linked immunoabsorbance assays,
cell attachment assays and antibody-blocking assays to
determine the adhesive/anti-adhesive properties of the two
major tenascin-C splice variants with respect to fibronectin
and their effect on chondrosarcoma cell attachment. We found
that the small tenascin-C splice variant (220 kDa) binds to
fibronectin, whereas the large tenascin-C splice variant
(320 kDa) does not. In addition, the small tenascin-C splice
variant was found to decrease adhesion for cells when bound
to fibronectin, but contributed to adhesion when bound to
plastic in fibronectin-coated wells. Antibody blocking
experiments confirmed that both the small tenascin-C splice
variant and fibronectin contribute to cell adhesion when
bound to plastic. The large tenascin-C splice variant did
not promote specific cell attachment. We hypothesize that
the biologic activity of tenascin-C is dependent on the
tissue-specific splicing pattern. The smaller tenascin-C
isoform likely plays a structural and adhesive role, whereas
the larger isoform, preferentially expressed in malignant
tissue, likely plays a role in cell egress and
metastasis.},
Key = {fds113184}
}
@article{fds113199,
Author = {G Schürmann and J Haspel and M Grumet and HP Erickson},
Title = {Cell adhesion molecule L1 in folded (horseshoe) and extended
conformations.},
Journal = {Molecular biology of the cell, United States},
Volume = {12},
Number = {6},
Pages = {1765-73},
Year = {2001},
Month = {June},
ISSN = {1059-1524},
Keywords = {Cell Adhesion • Cell Line • Centrifugation •
Electrophoresis, Polyacrylamide Gel • Glycosylation
• Humans • Immunoglobulins • Insect Proteins
• Leukocyte L1 Antigen Complex • Membrane
Glycoproteins • Microscopy, Electron • Neural Cell
Adhesion Molecules • Protein Conformation •
Protein Folding • Protein Structure, Tertiary •
Proteins • Recombinant Proteins • chemistry •
chemistry* • physiology*},
Abstract = {We have investigated the structure of the cell adhesion
molecule L1 by electron microscopy. We were particularly
interested in the conformation of the four N-terminal
immunoglobulin domains, because x-ray diffraction showed
that these domains are bent into a horseshoe shape in the
related molecules hemolin and axonin-1. Surprisingly,
rotary-shadowed specimens showed the molecules to be
elongated, with no indication of the horseshoe shape.
However, sedimentation data suggested that these domains of
L1 were folded into a compact shape in solution; therefore,
this prompted us to look at the molecules by an alternative
technique, negative stain. The negative stain images showed
a compact shape consistent with the expected horseshoe
conformation. We speculate that in rotary shadowing the
contact with the mica caused a distortion of the protein,
weakening the bonds forming the horseshoe and permitting the
molecule to extend. We have thus confirmed that the L1
molecule is primarily in the horseshoe conformation in
solution, and we have visualized for the first time its
opening into an extended conformation. Our study resolves
conflicting interpretations from previous electron
microscopy studies of L1.},
Key = {fds113199}
}
@article{fds113220,
Author = {J Takagi and HP Erickson and TA Springer},
Title = {C-terminal opening mimics 'inside-out' activation of
integrin alpha5beta1.},
Journal = {Nature structural biology, United States},
Volume = {8},
Number = {5},
Pages = {412-6},
Year = {2001},
Month = {May},
ISSN = {1072-8368},
Keywords = {Amino Acid Sequence • Cations, Divalent • Cell
Membrane • Cytoplasm • Dimerization •
Endopeptidases • Fibronectins • Humans •
Ligands • Microscopy, Electron • Models,
Biological • Molecular Sequence Data • Peptide
Fragments • Protein Binding • Protein Engineering
• Protein Structure, Tertiary • Protein Subunits
• Receptors, Fibronectin • Signal Transduction*
• Solubility • chemistry • chemistry* •
metabolism • metabolism* • ultrastructure},
Abstract = {Integrins are adhesion molecules that convey signals both to
and from the cytoplasm across the plasma membrane. In
resting cells, integrins in a low affinity state can be
activated by 'inside-out signaling', in which signals
affecting integrin heterodimer cytoplasmic domains cause a
conformational change in the integrin ligand-binding
headpiece connected to the membrane by two long,
approximately 16 nm stalks. Here we demonstrate a mechanism
for conveying a conformational change over the long distance
from the plasma membrane to the headpiece. We prepared
soluble, alpha5beta1 integrin heterodimer extracellular
fragments in which interactions between alpha- and
beta-subunit cytoplasmic domains were replaced with an
artificial clasp. Release of this C-terminal clasp by
specific protease cleavage resulted in an approximately 14
nm separation of the stalks coupled to increased binding to
fibronectin. This activation did not require any associated
molecules or clustering and was observed with physiological
concentrations of divalent cations. These findings suggest
that the overall mechanism for integrin inside-out
activation involves the spatial separation of the
cytoplasmic and/or transmembrane domains.},
Key = {fds113220}
}
@article{fds113194,
Author = {L Romberg and M Simon and HP Erickson},
Title = {Polymerization of Ftsz, a bacterial homolog of tubulin. is
assembly cooperative?},
Journal = {The Journal of biological chemistry, United
States},
Volume = {276},
Number = {15},
Pages = {11743-53},
Year = {2001},
Month = {April},
ISSN = {0021-9258},
Keywords = {Bacterial Proteins • Biopolymers • Cytoskeletal
Proteins* • Escherichia coli • Guanine Nucleotides
• Guanosine Triphosphate • Microscopy, Electron
• Protein Conformation • chemistry •
metabolism • metabolism* • ultrastructure},
Abstract = {FtsZ is a bacterial homolog of tubulin that is essential for
prokaryotic cytokinesis. In vitro, GTP induces FtsZ to
assemble into straight, 5-nm-wide polymers. Here we show
that the polymerization of these FtsZ filaments most closely
resembles noncooperative (or "isodesmic") assembly; the
polymers are single-stranded and assemble with no evidence
of a nucleation phase and without a critical concentration.
We have developed a model for the isodesmic polymerization
that includes GTP hydrolysis in the scheme. The model can
account for the lengths of the FtsZ polymers and their
maximum steady state nucleotide hydrolysis rates. It
predicts that unlike microtubules, FtsZ protofilaments
consist of GTP-bound FtsZ subunits that hydrolyze their
nucleotide only slowly and are connected by high affinity
longitudinal bonds with a nanomolar K(D).},
Key = {fds113194}
}
@article{fds113188,
Author = {T Sakai and KJ Johnson and M Murozono and K Sakai and MA Magnuson and T
Wieloch, T Cronberg and A Isshiki and HP Erickson and R
Fässler},
Title = {Plasma fibronectin supports neuronal survival and reduces
brain injury following transient focal cerebral ischemia but
is not essential for skin-wound healing and
hemostasis.},
Journal = {Nature medicine, United States},
Volume = {7},
Number = {3},
Pages = {324-30},
Year = {2001},
Month = {March},
ISSN = {1078-8956},
Keywords = {Animals • Brain • Cell Survival •
Fibronectins • Hemostasis • Integrases •
Ischemic Attack, Transient • Mice • Mice, Knockout
• Neurons • Recombination, Genetic • Skin
• Viral Proteins* • Wound Healing • cytology*
• genetics • metabolism • pathology* •
physiology* • physiopathology*},
Abstract = {Fibronectin performs essential roles in embryonic
development and is prominently expressed during tissue
repair. Two forms of fibronectin have been identified:
plasma fibronectin (pFn), which is expressed by hepatocytes
and secreted in soluble form into plasma; and cellular
fibronectin (cFn), an insoluble form expressed locally by
fibroblasts and other cell types and deposited and assembled
into the extracellular matrix. To investigate the role of
pFn in vivo, we generated pFn-deficient adult mice using
Cre-loxP conditional gene-knockout technology. Here we show
that pFn-deficient mice show increased neuronal apoptosis
and larger infarction areas following transient focal
cerebral ischemia. However, pFn is dispensable for
skin-wound healing and hemostasis.},
Key = {fds113188}
}
@article{fds113157,
Author = {HP Erickson},
Title = {The FtsZ protofilament and attachment of ZipA--structural
constraints on the FtsZ power stroke.},
Journal = {Current opinion in cell biology, United States},
Volume = {13},
Number = {1},
Pages = {55-60},
Year = {2001},
Month = {February},
ISSN = {0955-0674},
Keywords = {Amino Acid Sequence • Bacterial Proteins • Carrier
Proteins • Cell Cycle Proteins • Cell Division
• Cytoskeletal Proteins* • Escherichia coli
Proteins* • Models, Molecular • Molecular Sequence
Data • Protein Conformation • Structure-Activity
Relationship • chemistry* • physiology •
physiology*},
Abstract = {Bacterial cell division protein FtsZ forms protofilaments in
vitro that can shift from a straight to a curved
conformation. The inside of the curved protofilaments, which
corresponds to the carboxyl terminus, should face the center
of the cell as curvature increases during constriction of
the Z-ring. ZipA, a membrane-tethered division protein,
binds to a highly conserved short peptide on the carboxyl
terminus of FtsZ. A model is proposed here for how
membrane-bound ZipA can reach around the FtsZ protofilament
to bind the carboxy-terminal peptide, which faces away from
the membrane.},
Key = {fds113157}
}
@article{fds113103,
Author = {C Lu and J Stricker and HP Erickson},
Title = {Site-specific mutations of FtsZ--effects on GTPase and in
vitro assembly.},
Journal = {BMC microbiology, England},
Volume = {1},
Pages = {7},
Year = {2001},
ISSN = {1471-2180},
Keywords = {Cell Division • Escherichia coli • GTP
Phosphohydrolases • Genetic Complementation Test •
Guanosine Triphosphate • Mutagenesis, Site-Directed
• enzymology • genetics • metabolism* •
physiology},
Abstract = {BACKGROUND: FtsZ, the major cytoskeletal protein in
bacterial cytokinesis, assembles in vitro into
protofilaments, which can further associate into sheets,
bundles or tubes. We have constructed 16 site-directed
mutants of E. coli ftsZ, and tested them for GTP hydrolysis
and assembly in vitro, and for their ability to complement
the temperature sensitive ftsZ84 mutation in E. coli.
RESULTS: The mutants were grouped into three classes. Benign
mutants, which mapped mostly to the front and back surface
of the protofilament, were able to complement ftsZ84 in vivo
and showed normal assembly in vitro. GTP contact mutations
had less than 10% of wild type GTPase activity. They could
all assemble in vitro, and several of these mutants could
complement ftsZ84. A third, and newly discovered, class of
mutations mapped to the sides of the protofilaments. These
lateral mutants had mostly normal GTPase and assembly in
vitro, but none of them complemented ftsZ84. The
non-complementing mutants showed greatly reduced expression
from the pBS58 vector, suggesting possible dominant negative
effects. CONCLUSIONS: Several mutants with greatly reduced
GTPase could still complement ftsZ84, suggesting that the
high level of GTPase observed in vitro is not essential for
in vivo function. All of the lateral mutants failed to
complement ftsZ84, which suggests that these surfaces of the
protofilaments are important for function in cell division.
These lateral surfaces may mediate association of FtsZ
protofilaments into pairs or small sheets, although their
structure is apparently different from the sheets assembled
in DEAE dextran or calcium.},
Key = {fds113103}
}
@article{fds113142,
Author = {MA Ghert and ST Jung and W Qi and JM Harrelson and HP Erickson and JA
Block, SP Scully},
Title = {The clinical significance of tenascin-C splice variant
expression in chondrosarcoma.},
Journal = {Oncology, Switzerland},
Volume = {61},
Number = {4},
Pages = {306-14},
Year = {2001},
ISSN = {0030-2414},
Keywords = {Adult • Alternative Splicing* • Base Sequence
• Bone Neoplasms • Child • Chondrosarcoma
• DNA Primers • Female • Humans • Male
• Middle Aged • RNA, Messenger • Reverse
Transcriptase Polymerase Chain Reaction • Survival Rate
• Tenascin • Time Factors • Transcription,
Genetic • Tumor Cells, Cultured • Variation
(Genetics)* • genetics • genetics* •
mortality • pathology • surgery},
Abstract = {OBJECTIVES: Tenascin-C (TNC) is an oligomeric glycoprotein
of the extracellular matrix that is prominently expressed in
malignant tumors. The purpose of this study was: (1) to
determine the in vitro TNC splicing pattern in cultured
human chondrocytes and chondrosarcoma cells, (2) to
determine the in vivo TNC splicing pattern in clinical
chondrosarcoma specimens, and (3) to perform survival
analysis based on the TNC splicing pattern of the tumor
specimens. METHODS: Human articular chondrocytes and
chondrosarcoma cells (cell line JJ012) were grown in a
three-dimensional alginate bead system and harvested at two
time points. Semiquantitative reverse transcription
polymerase chain reaction (RT-PCR) was used to determine the
in vitro TNC splicing pattern for the two cell types.
Clinical chondrosarcoma specimens were obtained
intra-operatively and underwent RT-PCR to determine the in
vivo TNC splicing pattern. Specific immunohistochemical
staining for the large TNC splice variant was performed on
the clinical specimens. Survival analysis was used to
determine the association between the specific TNC splicing
pattern and survival. RESULTS: The in vitro mRNA expression
pattern of TNC in normal human articular chondrocytes was
characterized by a high ratio of the small to the large
splice variant (TNC(small):TNC(large)), whereas the in vitro
mRNA expression pattern for cultured chondrosarcoma cells
was characterized by a low TNC(small):TNC(large) ratio.
Clinical chondrosarcoma specimens with a lower
TNC(small):TNC(large) ratio showed a trend towards decreased
survival. The TNC splicing pattern of these specimens was
verified through specific immunohistochemical staining for
the large TNC isoform. CONCLUSIONS: The specific TNC
splicing pattern may have clinical significance in
chondrosarcoma. TNC expression may therefore play a future
role in objective tumor grading and novel therapeutic
approaches to this malignancy.},
Key = {fds113142}
}
@article{fds113104,
Author = {MB Champagne and KA Edwards and HP Erickson and DP
Kiehart},
Title = {Drosophila stretchin-MLCK is a novel member of the
Titin/Myosin light chain kinase family.},
Journal = {Journal of molecular biology, ENGLAND},
Volume = {300},
Number = {4},
Pages = {759-77},
Year = {2000},
Month = {July},
ISSN = {0022-2836},
Keywords = {Alternative Splicing • Amino Acid Motifs • Amino
Acid Sequence • Animals • Base Sequence •
Caenorhabditis elegans Proteins* • Catalytic Domain
• Cloning, Molecular • Drosophila Proteins* •
Drosophila melanogaster • Exons • Genes, Insect
• Helminth Proteins • Immunoglobulins •
Insect Proteins • Isoenzymes • Molecular Sequence
Data • Molecular Weight • Multigene Family •
Muscle Proteins • Myosin-Light-Chain Kinase •
Phylogeny • Poly A • Promoter Regions (Genetics)
• Protein Kinases • Protein Structure, Tertiary
• RNA, Messenger • Repetitive Sequences, Amino
Acid • Sequence Alignment • analysis •
chemistry • enzymology* • genetics •
genetics* • metabolism • metabolism*},
Abstract = {Members of the titin/myosin light chain kinase family play
an essential role in the organization of the actin/myosin
cytoskeleton, especially in sarcomere assembly and function.
In Drosophila melanogaster, projectin is so far the only
member of this family for which a transcription unit has
been characterized. The locus of another member of this
family, a protein related to Myosin light chain kinase, was
also identified. The cDNA and genomic sequences published
explain only the shorter transcripts expressed by this
locus. Here, we report the complete molecular
characterization of this transcription unit, which spans 38
kb, includes 33 exons and accounts for transcripts up to 25
kb in length. This transcription unit contains both the
largest exon (12,005 nt) and the largest coding region
(25,213 nt) reported so far for Drosophila. This
transcription unit features both internal promoters and
internal polyadenylation signals, which enable it to express
seven different transcripts, ranging from 3.3 to 25 kb in
size. The latter encodes a huge, titin-like, 926 kDa kinase
that features two large PEVK-rich repeats, 32 immunoglobulin
and two fibronectin type-III domains, which we designate
stretchin-MLCK. In addition, the 3' end of the
stretchin-MLCK transcription unit expresses shorter
transcripts that encode 86 to 165 kDa isoforms of
stretchin-MLCK that are analogous to vertebrate Myosin light
chain kinases. Similarly, the 5' end of the Stretchin-Mlck
transcription unit can also express transcripts encoding
kettin and Unc-89-like isoforms, which share no sequences
with the MLCK-like transcripts. Thus, this locus can be
viewed as a single transcription unit, Stretchin-Mlck
(genetic abbreviation Strn-Mlck), that expresses large,
composite transcripts and protein isoforms (sequences
available at http://www.academicpress.com/jmb), as well as a
complex of two independent transcription units, the
Stretchin and Mlck transcription units (Strn and Mlck,
respectively) the result of a "gene fission" event, that
encode independent transcripts and proteins with distinct
structural and enzymatic functions.},
Key = {fds113104}
}
@article{fds113134,
Author = {HP Erickson},
Title = {Gamma-tubulin nucleation: template or protofilament?},
Journal = {Nature cell biology},
Volume = {2},
Number = {6},
Pages = {E93-6},
Year = {2000},
Month = {June},
ISSN = {1465-7392},
url = {http://dx.doi.org/10.1038/35014084},
Keywords = {Animals • Biopolymers • Microscopy, Electron
• Microtubules • Models, Biological* •
Protein Binding • Protein Structure, Quaternary •
Tubulin • chemistry • metabolism •
metabolism* • ultrastructure*},
Abstract = {Gamma-tubulin is known to nucleate microtubule assembly from
alpha/beta-tubulin, but the molecular mechanism by which
this process occurs is the subject of some controversy. Four
recent papers have provided new structural and biochemical
constraints on the models proposed for nucleation. These
have refined, but not yet resolved, the debate.},
Language = {eng},
Doi = {10.1038/35014084},
Key = {fds113134}
}
@article{fds113175,
Author = {K Yokoyama and HP Erickson and Y Ikeda and Y Takada},
Title = {Identification of amino acid sequences in fibrinogen gamma
-chain and tenascin C C-terminal domains critical for
binding to integrin alpha vbeta 3.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {275},
Number = {22},
Pages = {16891-8},
Year = {2000},
Month = {June},
ISSN = {0021-9258},
Keywords = {Amino Acid Sequence • Animals • CHO Cells •
Cells, Cultured • Cricetinae • Fibrinogen •
Humans • Models, Molecular • Molecular Sequence
Data • Protein Binding • Protein Conformation
• Receptors, Vitronectin • Recombinant Proteins
• Tenascin • chemistry • metabolism •
metabolism*},
Abstract = {Integrin alpha(v)beta(3) recognizes fibrinogen gamma and
alpha(E) chain C-terminal domains (gammaC and alpha(E)C) but
does not require the gammaC dodecapeptide sequence
HHLGGAKQAGDV(400-411) for binding to gammaC. We have
localized the alpha(v)beta(3) binding sites in gammaC using
gammaC-derived synthetic peptides. We found that two
peptides GWTVFQKRLDGSV(190-202) and GVYYQGGTYSKAS(346-358)
block the alpha(v)beta(3) binding to gammaC or alpha(E)C,
block the alpha(v)beta(3)-mediated clot retraction, and
induce the ligand-induced binding site 2 (LIBS2) epitope in
alpha(v)beta(3). Neither peptide affects fibrinogen binding
to alpha(IIb)beta(3). Scrambled or inverted peptides were
not effective. These results suggest that the two
gammaC-derived peptides directly interact with
alpha(v)beta(3) and specifically block alpha(v)beta(3)-gammaC
or alpha(E)C interaction. The two sequences are located next
to each other in the gammaC crystal structure, although they
are separate in the primary structure. Asp-199, Ser-201,
Gln-350, Thr-353, Lys-356, Ala-357, and Ser-358 residues are
exposed to the surface. This suggests that the two sequences
are part of alpha(v)beta(3) binding sites in fibrinogen
gammaC domain. We also found that tenascin C C-terminal
fibrinogen-like domain specifically binds to
alpha(v)beta(3). Notably, a peptide WYRNCHRVNLMGRYGDNNHSQGVNWFHWKG
from this domain that includes the sequence corresponding to
gammaC GVYYQGGTYSKAS(346-358) specifically binds to
alpha(v)beta(3), suggesting that fibrinogen and tenascin C
C-terminal domains interact with alpha(v)beta(3) in a
similar manner.},
Key = {fds113175}
}
@article{fds113173,
Author = {SD Redick and DL Settles and G Briscoe and HP Erickson},
Title = {Defining fibronectin's cell adhesion synergy site by
site-directed mutagenesis.},
Journal = {The Journal of cell biology},
Volume = {149},
Number = {2},
Pages = {521-7},
Year = {2000},
Month = {April},
ISSN = {0021-9525},
Keywords = {Amino Acid Sequence • Amino Acid Substitution •
Animals • Binding Sites • Binding, Competitive
• Cattle • Cell Adhesion • Chickens •
Fibronectins • Humans • K562 Cells • Kinetics
• Mice • Models, Molecular • Molecular
Sequence Data • Mutagenesis, Site-Directed •
Oligopeptides • Pleurodeles • Protein Conformation
• Rats • Receptors, Fibronectin • Recombinant
Proteins • Sequence Alignment • Sequence Homology,
Amino Acid • Xenopus • analysis • chemistry
• chemistry* • genetics • metabolism •
metabolism* • physiology*},
Abstract = {Fibronectin's RGD-mediated binding to the alpha5beta1
integrin is dramatically enhanced by a synergy site within
fibronectin III domain 9 (FN9). Guided by the crystal
structure of the cell-binding domain, we selected amino
acids in FN9 that project in the same direction as the RGD,
presumably toward the integrin, and mutated them to alanine.
R1379 in the peptide PHSRN, and the nearby R1374 have been
shown previously to be important for alpha5beta1-mediated
adhesion (Aota, S., M. Nomizu, and K.M. Yamada. 1994. J.
Biol. Chem. 269:24756-24761). Our more extensive set of
mutants showed that R1379 is the key residue in the
synergistic effect, but other residues contribute
substantially. R1374A decreased adhesion slightly by itself,
but the double mutant R1374A-R1379A was significantly less
adhesive than R1379A alone. Single mutations of R1369A,
R1371A, T1385A, and N1386A had negligible effects on cell
adhesion, but combining these substitutions either with
R1379A or each other gave a more dramatic reduction of cell
adhesion. The triple mutant R1374A/P1376A/R1379A had no
detectable adhesion activity. We conclude that, in addition
to the R of the PHRSN peptide, other residues on the same
face of FN9 are required for the full synergistic effect.
The integrin-binding synergy site is a much more extensive
surface than the small linear peptide sequence.},
Language = {eng},
Key = {fds113173}
}
@article{fds113145,
Author = {HP Erickson},
Title = {Dynamin and FtsZ. Missing links in mitochondrial and
bacterial division.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {148},
Number = {6},
Pages = {1103-5},
Year = {2000},
Month = {March},
ISSN = {0021-9525},
Keywords = {Animals • Bacteria • Bacterial Physiology* •
Bacterial Proteins • Cytoskeletal Proteins* •
Dynamins • GTP Phosphohydrolases • Microtubules
• Mitochondria • cytology* • metabolism*
• physiology • physiology* •
ultrastructure},
Key = {fds113145}
}
@article{fds113201,
Author = {AM Fong and HP Erickson and JP Zachariah and S Poon and NJ Schamberg and T
Imai, DD Patel},
Title = {Ultrastructure and function of the fractalkine mucin domain
in CX(3)C chemokine domain presentation.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {275},
Number = {6},
Pages = {3781-6},
Year = {2000},
Month = {February},
ISSN = {0021-9258},
Keywords = {Alkaline Phosphatase • Cell Adhesion • Cell
Adhesion Molecules • Centrifugation, Density Gradient
• Chemokines, CX3C* • Chemokines, CXC •
E-Selectin • Flow Cytometry • Humans •
Kinetics • Leukocytes • Membrane Proteins •
Microscopy, Electron • Mucins • Recombinant Fusion
Proteins • Tumor Cells, Cultured • analysis •
genetics • metabolism • metabolism* •
ultrastructure},
Abstract = {Fractalkine (FKN), a CX(3)C chemokine/mucin hybrid molecule
on endothelium, functions as an adhesion molecule to capture
and induce firm adhesion of a subset of leukocytes in a
selectin- and integrin-independent manner. We hypothesized
that the FKN mucin domain may be important for its function
in adhesion, and tested the ability of secreted alkaline
phosphatase (SEAP) fusion proteins containing the entire
extracellular region (FKN-SEAP), the chemokine domain
(CX3C-SEAP), or the mucin domain (mucin-SEAP) to support
firm adhesion under flow. CX3C-SEAP induced suboptimal firm
adhesion of resting peripheral blood mononuclear cells,
compared with FKN-SEAP, and mucin-SEAP induced no firm
adhesion. CX3C-SEAP and FKN-SEAP bound to CX(3)CR1 with
similar affinities. By electron microscopy, fractalkine was
29 nm in length with a long stalk (mucin domain), and a
globular head (CX(3)C). To test the function of the mucin
domain, a chimeric protein replacing the mucin domain with a
rod-like segment of E-selectin was constructed. This
chimeric protein gave the same adhesion of peripheral blood
mononuclear cells as intact FKN, both when immobilized on
glass and when expressed on the cell surface. This implies
that the function of the mucin domain is to provide a stalk,
extending the chemokine domain away from the endothelial
cell surface to present it to flowing leukocytes.},
Key = {fds113201}
}
@article{fds113085,
Author = {C Lu and M Reedy and HP Erickson},
Title = {Straight and curved conformations of FtsZ are regulated by
GTP hydrolysis.},
Journal = {Journal of bacteriology, UNITED STATES},
Volume = {182},
Number = {1},
Pages = {164-70},
Year = {2000},
Month = {January},
ISSN = {0021-9193},
Keywords = {Bacterial Proteins • Calcium • Chelating Agents
• Cytoskeletal Proteins* • DEAE-Dextran •
GTP-Binding Proteins • Guanosine Diphosphate •
Guanosine Triphosphate • Hydrolysis • Magnesium
• Microfilaments • Microscopy, Electron •
Protein Conformation • analogs & derivatives •
chemistry • chemistry* • metabolism •
metabolism* • ultrastructure},
Abstract = {FtsZ assembles in vitro into protofilaments that can adopt
two conformations-the straight conformation, which can
assemble further into two-dimensional protofilament sheets,
and the curved conformation, which forms minirings about 23
nm in diameter. Here, we describe the structure of FtsZ
tubes, which are a variation of the curved conformation. In
the tube the curved protofilament forms a shallow helix with
a diameter of 23 nm and a pitch of 18 or 24 degrees. We
suggest that this shallow helix is the relaxed structure of
the curved protofilament in solution. We provide evidence
that GTP favors the straight conformation while GDP favors
the curved conformation. In particular, exclusively straight
protofilaments and protofilament sheets are assembled in
GMPCPP, a nonhydrolyzable GTP analog, or in GTP following
chelation of Mg, which blocks GTP hydrolysis. Assembly in
GDP produces exclusively tubes. The transition from straight
protofilaments to the curved conformation may provide a
mechanism whereby the energy of GTP hydrolysis is used to
generate force for the constriction of the FtsZ ring in cell
division.},
Key = {fds113085}
}
@article{fds113228,
Author = {C Lu and HP Erickson},
Title = {The straight and curved conformation of FtsZ
protofilaments-evidence for rapid exchange of GTP into the
curved protofilament.},
Journal = {Cell structure and function, Japan},
Volume = {24},
Number = {5},
Pages = {285-90},
Year = {1999},
Month = {October},
ISSN = {0386-7196},
Keywords = {Bacterial Proteins • Calcium • Cytoskeletal
Proteins • DEAE-Dextran • Edetic Acid •
Guanosine Diphosphate • Guanosine Triphosphate •
Lipid Bilayers • Macromolecular Substances •
Magnesium • Microscopy, Electron • Models,
Molecular • analogs & derivatives* • chemistry
• metabolism* • ultrastructure},
Abstract = {Bacterial cell division protein FtsZ assembles into
protofilaments, which can adopt a straight or curved
conformation, similar to its eukaryotic homolog, tubulin.
The straight protofilaments can assemble into sheets with a
lattice similar to the microtubule wall. The curved
protofilaments can form rings when adsorbed to a lipid
monolayer, but in solution they form helices. 4 helices
assemble together to make a tube, the characteristic polymer
of the curved protofilament. GTP favors the straight
conformation, while GDP favors the curved. We show here that
addition of EDTA and GTP to tubes causes a rapid
transformation to straight protofilament sheets. Apparently
when the magnesium is chelated the GDP in the curved
protofilaments dissociates rapidly and is replaced with GTP,
and this GTP induces the transition to straight
protofilaments.},
Key = {fds113228}
}
@article{fds113140,
Author = {KJ Johnson and H Sage and G Briscoe and HP Erickson},
Title = {The compact conformation of fibronectin is determined by
intramolecular ionic interactions.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {274},
Number = {22},
Pages = {15473-9},
Year = {1999},
Month = {May},
ISSN = {0021-9258},
Keywords = {Animals • Cattle • Dimerization •
Electrostatics • Fibronectins • Hydrogen-Ion
Concentration • Integrins • Models, Molecular
• Peptide Fragments • Protein Conformation* •
Recombinant Proteins • Salts • Thermolysin •
chemistry • chemistry* • genetics •
pharmacology},
Abstract = {Fibronectin exists in a compact or extended conformation,
depending upon environmental pH and salt concentration.
Using recombinant fragments expressed in bacteria and
baculovirus, we determined the domains responsible for
producing fibronectin's compact conformation. Our velocity
and equilibrium sedimentation data show that FN2-14 (a
protein containing FN-III domains 2 through 14) forms dimers
in low salt. Experiments with smaller fragments indicates
that the compact conformation is produced by binding of
FN12-14 of one subunit to FN2-3 of the other subunit in the
dimer. The binding is weakened at higher salt
concentrations, implying an electrostatic interaction.
Furthermore, segment FN7-14+A, which contains the
alternatively spliced A domain between FN11 and 12, forms
dimers, whereas FN7-14 without A does not. Segment FN12-14+A
also forms dimers, but the isolated A domain does not. These
data imply an association of domain A with FN12-14, and the
presence of A may favor an open conformation by competing
with FN2-3 for binding to FN12-14.},
Key = {fds113140}
}
@article{fds113101,
Author = {T Ohashi and DP Kiehart and HP Erickson},
Title = {Dynamics and elasticity of the fibronectin matrix in living
cell culture visualized by fibronectin-green fluorescent
protein.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America},
Volume = {96},
Number = {5},
Pages = {2153-8},
Year = {1999},
Month = {March},
ISSN = {0027-8424},
Keywords = {Amino Acid Sequence • Animals • CHO Cells •
Cell Membrane • Cells, Cultured • Cricetinae
• Elasticity • Extracellular Matrix •
Fibronectins • Green Fluorescent Proteins •
Kinetics • Luminescent Proteins • Mutagenesis,
Insertional • Polymerase Chain Reaction •
Recombinant Fusion Proteins • Time Factors •
Transfection • analysis • analysis* •
chemistry • genetics • metabolism •
physiology* • ultrastructure},
Abstract = {Fibronectin (FN) forms the primitive fibrillar matrix in
both embryos and healing wounds. To study the matrix in
living cell cultures, we have constructed a cell line that
secretes FN molecules chimeric with green fluorescent
protein. These FN-green fluorescent protein molecules were
assembled into a typical matrix that was easily visualized
by fluorescence over periods of several hours. FN fibrils
remained mostly straight, and they were seen to extend and
contract to accommodate movements of the cells, indicating
that they are elastic. When fibrils were broken or detached
from cells, they contracted to less than one-fourth of their
extended length, demonstrating that they are highly
stretched in the living culture. Previous work from other
laboratories has suggested that cryptic sites for FN
assembly may be exposed by tension on FN. Our results show
directly that FN matrix fibrils are not only under tension
but are also highly stretched. This stretched state of FN is
an obvious candidate for exposing the cryptic assembly
sites.},
Language = {eng},
Key = {fds113101}
}
@article{fds113095,
Author = {T Ohashi and HP Erickson},
Title = {Oligomeric structure and tissue distribution of ficolins
from mouse, pig and human.},
Journal = {Archives of biochemistry and biophysics},
Volume = {360},
Number = {2},
Pages = {223-32},
Year = {1998},
Month = {December},
ISSN = {0003-9861},
url = {http://dx.doi.org/10.1006/abbi.1998.0957},
Keywords = {Amidohydrolases • Animals • Blotting, Northern
• Blotting, Western • Bone Marrow • CHO Cells
• Carrier Proteins • Chromatography, Liquid •
Cloning, Molecular • Cricetinae • Disulfides
• Humans • Immune Sera • Lectins* •
Liver • Mice • Models, Molecular • Molecular
Weight • Peptide-N4-(N-acetyl-beta-glucosaminyl)
Asparagine Amidase • Protein Conformation •
Protein Sorting Signals • Recombinant Proteins •
Swine • blood • chemistry* • genetics •
genetics* • immunology • isolation & purification
• metabolism},
Abstract = {Mouse plasma ficolin was purified by GlcNAc affinity and
anion-exchange chromatography. Gel-filtration chromatography
and gradient sedimentation indicated that mouse plasma
ficolin is a 12-mer of approximately 35 kDa subunits, and
electron microscopy showed the same parachute-like structure
previously characterized for the pig ficolin 12-mer. Whereas
the predominant form in pig plasma is a 24-mer, mouse and
human plasma ficolin showed only the 12-mer form. We
conclude that mouse plasma ficolin corresponds to the
recently described ficolin A. We have identified a second
mouse ficolin gene, ficolin B, which means that pig and
mouse each have two ficolin genes, and human has three. One
ficolin gene in all species is expressed in liver and is the
primary source of plasma ficolin. Expression of this gene in
other tissues, and expression of the second ficolin gene,
appears to vary in different species.},
Language = {eng},
Doi = {10.1006/abbi.1998.0957},
Key = {fds113095}
}
@article{fds113115,
Author = {J Kumar and HP Erickson and MP Sheetz},
Title = {Ultrastructural and biochemical properties of the 120-kDa
form of chick kinectin.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {273},
Number = {48},
Pages = {31738-43},
Year = {1998},
Month = {November},
ISSN = {0021-9258},
Keywords = {Amino Acid Sequence • Animals • Antibodies,
Monoclonal • Binding Sites, Antibody • Cells,
Cultured • Chick Embryo • Chickens • DNA,
Complementary • Membrane Proteins* • Microscopy,
Electron • Molecular Sequence Data • Molecular
Weight • Myristic Acid • Protein Conformation
• RNA, Messenger • Receptors, Cell Surface •
chemistry* • genetics • metabolism •
ultrastructure*},
Abstract = {Kinectin, an integral membrane protein (160 kDa), was
identified as a kinesin-binding protein. Analysis of the
predicted amino acid sequence of kinectin cDNA indicated an
alpha-helical coiled-coil structure from amino acid 320 to
1310. A 120-kDa kinectin has been observed consistently, and
N-terminal sequencing showed that 232 amino acids were
missing from the N terminus of full-length kinectin. 120-kDa
kinectin was distributed in the supernatant and a low
density fraction of vesicles, whereas both forms were in the
high density fraction of vesicles. In the electron
microscope, the 120-kDa form appeared as a linear molecule
of 133 nm in length. In hydrodynamic studies, the cytosolic
120-kDa kinectin was a dimer. Monoclonal antibody molecules
(anti-kinectin KR160.9) bound asymmetrically to kinectin
often with two antibodies/kinectin, indicative of a parallel
coiled-coil. Metabolic labeling with [3H]myristic acid
showed that both the 120- and 160-kDa kinectin are
myristoylated in chick embryo fibroblasts. The
myristoylation of 120-kDa kinectin may provide a mechanism
for linking it to a low density fraction of vesicles.
Immunoprecipitation with a 160-kDa kinectin-specific
antibody brought down the 120-kDa kinectin. Thus, we suggest
that kinectin is an extended parallel coiled-coil dimer,
often a heterodimer.},
Key = {fds113115}
}
@article{fds113128,
Author = {TE Melby and CN Ciampaglio and G Briscoe and HP Erickson},
Title = {The symmetrical structure of structural maintenance of
chromosomes (SMC) and MukB proteins: long, antiparallel
coiled coils, folded at a flexible hinge.},
Journal = {The Journal of cell biology},
Volume = {142},
Number = {6},
Pages = {1595-604},
Year = {1998},
Month = {September},
ISSN = {0021-9525},
Keywords = {Bacterial Proteins • Chromosomal Proteins, Non-Histone*
• Chromosomes, Bacterial • Escherichia coli
Proteins* • Nuclear Proteins • Protein Folding
• chemistry • ultrastructure •
ultrastructure*},
Abstract = {Structural maintenance of chromosomes (SMC) proteins
function in chromosome condensation and several other
aspects of DNA processing. They are large proteins
characterized by an NH2-terminal nucleotide triphosphate
(NTP)-binding domain, two long segments of coiled coil
separated by a hinge, and a COOH-terminal domain. Here, we
have visualized by EM the SMC protein from Bacillus subtilis
(BsSMC) and MukB from Escherichia coli, which we argue is a
divergent SMC protein. Both BsSMC and MukB show two thin
rods with globular domains at the ends emerging from the
hinge. The hinge appears to be quite flexible: the arms can
open up to 180 degrees, separating the terminal domains by
100 nm, or close to near 0 degrees, bringing the terminal
globular domains together. A surprising observation is that
the approximately 300-amino acid-long coiled coils are in an
antiparallel arrangement. Known coiled coils are almost all
parallel, and the longest antiparallel coiled coils known
previously are 35-45 amino acids long. This antiparallel
arrangement produces a symmetrical molecule with both an
NH2- and a COOH-terminal domain at each end. The SMC
molecule therefore has two complete and identical functional
domains at the ends of the long arms. The bifunctional
symmetry and a possible scissoring action at the hinge
should provide unique biomechanical properties to the SMC
proteins.},
Language = {eng},
Key = {fds113128}
}
@article{fds113182,
Author = {AF Oberhauser and PE Marszalek and HP Erickson and JM
Fernandez},
Title = {The molecular elasticity of the extracellular matrix protein
tenascin.},
Journal = {Nature, ENGLAND},
Volume = {393},
Number = {6681},
Pages = {181-5},
Year = {1998},
Month = {May},
ISSN = {0028-0836},
Keywords = {Alternative Splicing • Binding Sites • Elasticity*
• Fibronectins • Humans • Microscopy, Atomic
Force • Monte Carlo Method • Peptide Fragments
• Protein Folding • Recombinant Proteins •
Tenascin • chemistry • genetics •
physiology*},
Abstract = {Extracellular matrix proteins are thought to provide a rigid
mechanical anchor that supports and guides migrating and
rolling cells. Here we examine the mechanical properties of
the extracellular matrix protein tenascin by using
atomic-force-microscopy techniques. Our results indicate
that tenascin is an elastic protein. Single molecules of
tenascin could be stretched to several times their resting
length. Force-extension curves showed a saw-tooth pattern,
with peaks of force at 137pN. These peaks were approximately
25 nm apart. Similar results have been obtained by study of
titin. We also found similar results by studying recombinant
tenascin fragments encompassing the 15 fibronectin type III
domains of tenascin. This indicates that the extensibility
of tenascin may be due to the stretch-induced unfolding of
its fibronectin type III domains. Refolding of tenascin
after stretching, observed when the force was reduced to
near zero, showed a double-exponential recovery with time
constants of 42 domains refolded per second and 0.5 domains
per second. The former speed of refolding is more than twice
as fast as any previously reported speed of refolding of a
fibronectin type III domain. We suggest that the
extensibility of the modular fibronectin type III region may
be important in allowing tenascin-ligand bonds to persist
over long extensions. These properties of fibronectin type
III modules may be of widespread use in extracellular
proteins containing such domain.},
Key = {fds113182}
}
@article{fds113105,
Author = {M Seiffert and SC Beck and F Schermutzki and CA Müller and HP Erickson and G Klein},
Title = {Mitogenic and adhesive effects of tenascin-C on human
hematopoietic cells are mediated by various functional
domains.},
Journal = {Matrix biology : journal of the International Society for
Matrix Biology, GERMANY},
Volume = {17},
Number = {1},
Pages = {47-63},
Year = {1998},
Month = {April},
ISSN = {0945-053X},
Keywords = {Binding Sites • Cell Adhesion • Cells, Cultured
• Hematopoietic Stem Cells • Heparin • Humans
• Mitogens • Peptide Mapping • Recombinant
Proteins • Tenascin • drug effects • drug
effects* • genetics • pharmacology •
pharmacology* • physiology • physiology*},
Abstract = {In the adult organism, the extracellular matrix molecule
tenascin-C is prominently expressed in the bone marrow. Bone
marrow mononuclear cells can adhere to plastic-immobilized
tenascin-C, and in the present study we have used bacterial
expression proteins to map the domains of tenascin-C
responsible for binding of hematopoietic cells. A strong
binding site was found to be located within the
fibrinogen-like domain, and this binding could be inhibited
by heparin, suggesting interactions with membrane-bound
heparan sulfate proteoglycans. A second strong binding site
was identified within the fibronectin type III-like repeats
6-8, and was also inhibitable by heparin. Adhesion to both
attachment sites could not be blocked by various
anti-integrin antibodies. A third hematopoietic cell binding
site is located in the fibronectin type III-like repeats
1-5, which harbor an RGD sequence in the third fibronectin
type III-like repeat. Binding to this domain, however, seems
to be RGD-independent, since RGD-containing peptides could
not inhibit cell binding; the addition of heparin also did
not block adhesion to this domain. Since contradictory
results had been reported on a proliferative effect of
soluble tenascin-C, we also analyzed its activity on
hematopoietic cells. The heterogeneous bone marrow
mononuclear cells show a striking proliferative response in
the presence of tenascin-C which is concentration-dependent.
This result indicates a strong mitogenic activity of
tenascin-C on primary hematopoietic cells. Using recombinant
fragments of human tenascin-C, we identified several
mitogenic domains within the tenascin-C molecule. These
adhesive and mitogenic effects of tenascin-C suggest a
direct functional association with proliferation and
differentiation of hematopoietic cells within the bone
marrow microenvironment.},
Key = {fds113105}
}
@article{fds113178,
Author = {S Denda and U Müller and KL Crossin and HP Erickson and LF
Reichardt},
Title = {Utilization of a soluble integrin-alkaline phosphatase
chimera to characterize integrin alpha 8 beta 1 receptor
interactions with tenascin: murine alpha 8 beta 1 binds to
the RGD site in tenascin-C fragments, but not to native
tenascin-C.},
Journal = {Biochemistry, UNITED STATES},
Volume = {37},
Number = {16},
Pages = {5464-74},
Year = {1998},
Month = {April},
ISSN = {0006-2960},
Keywords = {Alkaline Phosphatase • Amino Acid Sequence •
Animals • Base Sequence • Binding Sites •
Cell Adhesion • Chickens • Cloning, Molecular
• Dimerization • Humans • Integrin alpha
Chains* • Integrins • Mice • Molecular
Sequence Data • Oligopeptides • Peptide Fragments
• Protein Binding • Recombinant Fusion Proteins
• Repetitive Sequences, Nucleic Acid • Solubility
• Tenascin • chemistry • genetics •
genetics* • isolation & purification • metabolism
• metabolism*},
Abstract = {The integrin alpha 8 beta 1 has been reported to bind to
fibronectin, vitronectin, and tenascin-C in cell adhesion or
neurite outgrowth assays. Here, we describe cDNA cloning of
the murine alpha 8 subunit, purification of a recombinant
soluble heterodimer consisting of the extracellular domains
of the murine alpha 8 and beta1 subunits, and development of
a sensitive binding assay using a modified form of this
heterodimer fused to alkaline phosphatase (AP). In binding
assays, the purified alpha 8 beta 1-AP chimera exhibited the
same divalent ion requirements for activation and binding
specificity as cell surface alpha 8 beta 1: in the presence
of Mn2+ it bound to fibronectin and vitronectin in an
RGDS-peptide inhibitable manner. Contrary to previous
reports, we found no evidence that alpha 8 beta 1, expressed
on K562 cells or as an AP chimera, interacts strongly with
native tenascin-C. In binding, adhesion, and spreading
assays, significant interactions were observed only to short
fragments of tenascin-C containing the third fibronectin
type III repeat which contains an RGD sequence. Full length
tenascin-C and longer fragments containing this repeat did
not appear to serve as ligands, implying that the RGD site
in native tenascin-C is a cryptic binding site for this
integrin, exposed by removal of adjacent domains. Soluble
integrin-AP chimeras should be generally useful for
identifying and characterizing integrin interactions with
ligands.},
Key = {fds113178}
}
@article{fds113204,
Author = {HP Erickson},
Title = {Atomic structures of tubulin and FtsZ.},
Journal = {Trends in cell biology, ENGLAND},
Volume = {8},
Number = {4},
Pages = {133-7},
Year = {1998},
Month = {April},
ISSN = {0962-8924},
Keywords = {Amino Acid Sequence • Animals • Bacterial Proteins
• Crystallography, X-Ray • Cytoskeletal Proteins*
• GTP-Binding Proteins • Humans • Models,
Molecular • Molecular Sequence Data • Protein
Structure, Tertiary* • Tubulin •
chemistry*},
Abstract = {The recently published atomic structures of tubulin and FtsZ
are a research milestone. The N-terminal GTP-binding domains
of tubulin and FtsZ are virtually identical in structure, as
expected from the substantial sequence identity. Sequence
identity is absent from the C-terminal domains, but they
also have virtually identical structures. A surprising
finding is that the N-terminal GTP-binding domain is
structurally homologous to that of Ras and other G proteins,
despite the completely different GTP-binding sequence
motifs. This article discusses these findings and the
molecular mechanisms that can now be addressed with the
atomic structures.},
Key = {fds113204}
}
@article{fds113221,
Author = {M Akke and J Liu and J Cavanagh and HP Erickson and AG
Palmer},
Title = {Pervasive conformational fluctuations on microsecond time
scales in a fibronectin type III domain.},
Journal = {Nature structural biology, UNITED STATES},
Volume = {5},
Number = {1},
Pages = {55-9},
Year = {1998},
Month = {January},
ISSN = {1072-8368},
Keywords = {Diffusion • Dimerization • Fibronectins •
Humans • Hydrogen Bonding • Motion • Nuclear
Magnetic Resonance, Biomolecular • Protein Binding
• Protein Conformation • Protein Denaturation
• Protein Structure, Tertiary • Tenascin •
chemistry*},
Abstract = {A novel off-resonance rotating-frame 15N NMR spin relaxation
experiment is used to characterize conformational
fluctuations with correlation times between 32 and 175
microseconds in the third fibronectin type III domain of
human tenascin-C. Conformational fluctuations of contiguous
regions of the beta-sandwich structure of the type III
domain may represent collective motions, such as transient
twisting or breathing of the beta-sheets. Flexibility of the
loop containing the Arg-Gly-Asp (RGD) tripeptide may affect
the accessibility of this motif in protein-protein
interactions.},
Key = {fds113221}
}
@article{fds113086,
Author = {C Lu and HP Erickson},
Title = {Purification and assembly of FtsZ.},
Journal = {Methods in enzymology, UNITED STATES},
Volume = {298},
Pages = {305-13},
Year = {1998},
ISSN = {0076-6879},
Keywords = {Ammonium Sulfate • Bacterial Proteins •
Biopolymers • Cytoskeletal Proteins* •
DEAE-Dextran • Escherichia coli • GTP
Phosphohydrolases • Guanosine Diphosphate •
Guanosine Triphosphate • Hydrogen-Ion Concentration
• Microscopy, Electron • Precipitation •
Protein Conformation • chemistry • isolation &
purification* • metabolism • metabolism* •
ultrastructure},
Key = {fds113086}
}
@article{fds113097,
Author = {C Lu and J Stricker and HP Erickson},
Title = {FtsZ from Escherichia coli, Azotobacter vinelandii, and
Thermotoga maritima--quantitation, GTP hydrolysis, and
assembly.},
Journal = {Cell motility and the cytoskeleton, UNITED
STATES},
Volume = {40},
Number = {1},
Pages = {71-86},
Year = {1998},
ISSN = {0886-1544},
Keywords = {Animals • Azotobacter vinelandii • Bacterial
Proteins • Chemical Fractionation • Cytoskeletal
Proteins* • Escherichia coli • GTP
Phosphohydrolases • GTP-Binding Proteins • Gene
Expression • Gram-Negative Anaerobic Bacteria •
Guanosine Triphosphate • Hydrolysis •
Microfilaments • Potassium • Rabbits •
Recombinant Fusion Proteins • Sodium • Temperature
• enzymology* • genetics • metabolism •
metabolism* • physiology},
Abstract = {We have cloned the ftsZ genes from Thermotoga maritima and
Azotobacter vinelandii and expressed the proteins (TmFtsZ
and AzFtsZ) in Escherichia coli. We compared these proteins
to E. coli FtsZ (EcFtsZ), and found that several remarkable
features of their GTPase activities were similar for all
three species, implying that these characteristics may be
universal among FtsZs. Using a calibrated protein assay, we
found that all three FtsZs bound 1 mole guanine nucleotide
per mole FtsZ and hydrolyzed GTP at high rates (> 2 GTP per
FtsZ per min). All three required magnesium and a monovalent
cation for GTP hydrolysis. Previous reports showed that
EcFtsZ (and some other species) required potassium. We
confirmed this specificity for EcFtsZ but found that
potassium and sodium both worked for Az- and TmFtsZ.
Specific GTPase activity had a striking dependence on FtsZ
concentration: activity (per FtsZ molecule) was absent or
low below 50 microg/ml, rose steeply from 50 to 300
microg/ml and plateaued at a constant high value above 300
microg/ml. This finding suggests that the active state
requires a polymer that is assembled cooperatively at 50-300
microg/ml. A good candidate for the active polymer was
visualized by negative stain electron microscopy--straight
protofilaments and protofilament pairs were seen under all
conditions with active GTPase. We suggest that the GTP
hydrolysis of FtsZ may be coupled to assembly, as it is for
tubulin, with hydrolysis occurring shortly after an FtsZ
monomer associates onto a protofilament end. As a part of
this study, we determined the concentration of EcFtsZ and
TmFtsZ by quantitative amino acid analysis and used this to
standardize the bicinchonic acid colorimetric assay. This is
the first accurate determination of FtsZ concentration.
Using this standard and quantitative Western blotting, we
determined that the average E. coli cell has 15,000
molecules of FtsZ, at a concentration of 400 microg/ml. This
is just above the plateau for full GTPase activity in
vitro.},
Key = {fds113097}
}
@article{fds113123,
Author = {C Lu and HP Erickson},
Title = {Expression in Escherichia coli of the thermostable DNA
polymerase from Pyrococcus furiosus.},
Journal = {Protein expression and purification, UNITED
STATES},
Volume = {11},
Number = {2},
Pages = {179-84},
Year = {1997},
Month = {November},
ISSN = {1046-5928},
Keywords = {Archaeal Proteins • DNA-Directed DNA Polymerase •
Escherichia coli • Polymerase Chain Reaction •
Pyrococcus • Recombinant Proteins • biosynthesis
• biosynthesis* • enzymology* • genetics
• methods},
Abstract = {Pfu, the DNA polymerase from Pyrococcus furiosus, has the
lowest error rate of any known polymerase in polymerase
chain reaction (PCR) amplification. Previously the protein
has been purified from P. furiosus bacterial cultures, and a
recombinant form has been produced in a baculovirus system.
We have produced a pET plasmid for expression of Pfu in
Escherichia coli (the expression plasmid pETpfu is available
from ATCC, Accession No. 87496) and found that this plasmid
is toxic or unstable in the expressing strain BL21(DE3),
even in the absence of induction. However, the plasmid was
stable in BL21(DE3) containing the pLysS plasmid, which
suppresses expression prior to induction, and a 90-kDa
protein was expressed upon addition of isopropyl
beta-D-thiogalactopyranoside. The protein was purified by
heating (to denature E. coli proteins), followed by
chromatography on P11 phosphocellulose and mono Q columns.
The purified protein had the same activity as the
commercially obtained baculovirus-expressed Pfu in both DNA
polymerase and PCR reactions. This bacterial expression
system appears to be the method of choice for production of
Pfu.},
Key = {fds113123}
}
@article{fds113197,
Author = {DA Siever and HP Erickson},
Title = {Extracellular annexin II.},
Journal = {The international journal of biochemistry & cell biology,
ENGLAND},
Volume = {29},
Number = {11},
Pages = {1219-23},
Year = {1997},
Month = {November},
ISSN = {1357-2725},
Keywords = {Annexin A2 • Cell Adhesion • Humans • Ligands
• Membrane Proteins • Models, Molecular •
Plasminogen Activators • Signal Transduction •
Tenascin • chemistry • physiology •
physiology* • therapeutic use},
Abstract = {Annexin II belongs to a family of calcium-dependent,
phospholipid binding proteins. Annexin II was first
identified as an intracellular protein and attributed
intracellular functions. Although it lacks a signal peptide
and its mechanism of secretion is unknown, extracellular
annexin II has recently been found in several tissues as
both soluble and membrane-bound protein. Cell-surface
annexin II has been identified as a receptor for a number of
polypeptide ligands. Extracellular annexin II may be
important in several biological processes, such as
fibrinolysis, cell adhesion, ligand-mediated cell signaling
and virus infection. These processes provide several
possibilities for therapeutic approaches targeting
extracellular annexin II, and future research should further
illuminate the biology of this molecule.},
Key = {fds113197}
}
@article{fds113183,
Author = {HP Erickson},
Title = {A tenascin knockout with a phenotype.},
Journal = {Nature genetics, UNITED STATES},
Volume = {17},
Number = {1},
Pages = {5-7},
Year = {1997},
Month = {September},
ISSN = {1061-4036},
Keywords = {Animals • Connective Tissue Diseases • Gene
Deletion* • Humans • Mice • Mice, Knockout
• Multigene Family • Phenotype • Sensitivity
and Specificity • Skin • Tenascin • chemistry
• deficiency* • genetics • genetics* •
metabolism},
Key = {fds113183}
}
@article{fds113214,
Author = {P Mehta and KD Patel and TM Laue and HP Erickson and RP
McEver},
Title = {Soluble monomeric P-selectin containing only the lectin and
epidermal growth factor domains binds to P-selectin
glycoprotein ligand-1 on leukocytes.},
Journal = {Blood, UNITED STATES},
Volume = {90},
Number = {6},
Pages = {2381-9},
Year = {1997},
Month = {September},
ISSN = {0006-4971},
Keywords = {Cell Adhesion • Epidermal Growth Factor • Humans
• Ligands • Membrane Glycoproteins •
Microscopy, Electron • Molecular Weight •
Neutrophils • P-Selectin • Protein Binding •
Solubility • Structure-Activity Relationship •
Ultracentrifugation • chemistry* • cytology*
• metabolism*},
Abstract = {Under shear stress, leukocytes use P-selectin glycoprotein
ligand-1 (PSGL-1) to tether to and roll on P-selectin
expressed on activated platelets or endothelial cells.
P-selectin has an NH2-terminal lectin domain, an epidermal
growth factor (EGF)-like motif, nine consensus repeats
(CRs), a transmembrane domain, and a cytoplasmic tail. To
determine whether the CRs are required for P-selectin to
bind PSGL-1, we expressed a soluble protein (Lec-EGF) that
contained only the lectin and EGF domains, plus a short
C-terminal epitope tag. Electron microscopy and hydrodynamic
analysis confirmed that Lec-EGF was monomeric, as previously
shown for soluble P-selectin (sPS) that contained the lectin
and EGF domains plus all nine CRs. Fluid-phase Lec-EGF or
sPS inhibited binding of oligomeric125I-labeled
membrane-derived P-selectin (mPS) to PSGL-1 on neutrophils
and binding of 125I-PSGL-1 to immobilized mPS. The IC50 for
inhibiting binding of mPS to neutrophils was fivefold
greater for Lec-EGF than for sPS, whereas the IC50 for
inhibiting binding of mPS to purified PSGL-1 was
indistinguishable for Lec-EGF and sPS. Under static or shear
conditions, neutrophils used PSGL-1 to tether to or roll on
Lec-EGF that was captured by an immobilized monoclonal
antibody to the C-terminal epitope. These data show that
P-selectin requires only the lectin and EGF domains to bind
to PSGL-1.},
Key = {fds113214}
}
@article{fds156448,
Author = {HP Erickson},
Title = {FtsZ, a tubulin homologue in prokaryote cell
division.},
Journal = {Trends in cell biology, England},
Volume = {7},
Number = {9},
Pages = {362-7},
Year = {1997},
Month = {September},
ISSN = {0962-8924},
Abstract = {Sequence alignments convincingly demonstrate that FtsZ is a
prokaryotic homologue of eukaryotic tubulins. FtsZ appears
to be universal in eubacteria and archaebacteria and has
also been identified in chloroplasts. Like tubulin, it
appears to have a cytoskeletal role as both proteins
assemble into two types of characteristic polymers in vitro
- protofilament sheets and mini-rings. Recent advances in
immunofluorescence and the use of green fluorescent protein
have provided clear images of FtsZ localized in a ring at
the septation site in bacteria, and new insights into
assembly of this Z-ring.},
Key = {fds156448}
}
@article{fds113091,
Author = {PA Carr and HP Erickson and AG Palmer},
Title = {Backbone dynamics of homologous fibronectin type III cell
adhesion domains from fibronectin and tenascin.},
Journal = {Structure (London, England : 1993), ENGLAND},
Volume = {5},
Number = {7},
Pages = {949-59},
Year = {1997},
Month = {July},
ISSN = {0969-2126},
Keywords = {Amino Acid Sequence • Cell Adhesion •
Extracellular Matrix Proteins • Fibronectins •
Humans • Kinetics • Magnetic Resonance
Spectroscopy • Molecular Conformation • Molecular
Sequence Data • Oligopeptides • Protein Structure,
Tertiary • Sequence Homology, Amino Acid •
Tenascin • chemistry • chemistry* •
metabolism • physiology},
Abstract = {BACKGROUND: Fibronectin type III domains are found as
autonomously-folded domains in a large variety of
multidomain proteins, including extracellular matrix
proteins. A subset of these domains employ an Arg-Gly-Asp
(RGD) tripeptide motif to mediate contact with cell-surface
receptors (integrins). This motif mediates protein-protein
interactions in a diverse range of biological processes,
such as in tissue development, would healing and metastasis.
The molecular basis for affinity and specificity of cell
adhesion via type III domains has not been clearly
established. The tenth type III domain from fibronectin
(FNfn10) and the third type III domain from tenascin-C
(TNfn3) have 27% sequence identity and share the same
overall protein fold, but present the RGD motifs in
different structural contexts. The dynamical properties of
the RGD motifs may affect the specificity and affinity of
the FNfn10 and TNfn3 domains. Structure-dynamics
correlations for these structurally homologous proteins may
reveal common molecular features which are important to the
dynamical properties of proteins. RESULTS: The
intramolecular dynamics of the protein backbones of FNfn10
and TNfn3 have been studied by 15N nuclear spin relaxation.
The FG loop in FNfn10, which contains the RGD motif,
exhibits extensive flexibility on picosecond to nanosecond
timescales, but motions on microsecond to millisecond
timescales are not observed. The equivalent region in TNfn3
is as rigid as regular elements of secondary structure. The
CC' loop also is more flexible on picosecond-nanosecond
timescales in FNfn10 than in TNfn3. Conformational exchange,
reflecting flexibility on microsecond-millisecond
timescales, is observed in beta strands A and B of both
FNfn10 and TNfn3. CONCLUSIONS: Comparison of the structures
of the FNfn10 and TNfn3 reveals several features related to
their different dynamical properties. The larger amplitude
motions of loops in FNfn10 are consistent with the
hypothesis that flexibility of these regions facilitates
induced-fit recognition of fibronectin by multiple
receptors. Similarly, the more rigid loops of TNfn3 may
reflect greater specificity for particular integrins. The
correlations observed between structural features and
dynamical properties of the homologous type III domains
indicate the influence of hydrogen bonding and hydrophobic
packing on dynamical fluctuations in proteins.},
Key = {fds113091}
}
@article{fds113206,
Author = {CY Chung and HP Erickson},
Title = {Glycosaminoglycans modulate fibronectin matrix assembly and
are essential for matrix incorporation of
tenascin-C.},
Journal = {Journal of cell science, ENGLAND},
Volume = {110 ( Pt 12)},
Pages = {1413-9},
Year = {1997},
Month = {June},
ISSN = {0021-9533},
Keywords = {Animals • CHO Cells • Cells, Cultured •
Cricetinae • Fibronectins • Fluorescent Antibody
Technique, Indirect • Glycosaminoglycans •
Glycosides • Heparan Sulfate Proteoglycans* •
Heparitin Sulfate • Humans • Proteoglycans •
Tenascin • drug effects • metabolism •
metabolism* • pharmacology • physiology*},
Abstract = {We have investigated the role of glycosaminoglycans in
fibronectin matrix assembly and the incorporation of
tenascin-C into matrix fibrils. Chinese hamster ovary cell
mutants with a total block in heparan and chondroitin
sulfate production failed to assemble a fibronectin matrix,
and incorporated no tenascin-C. Another mutant with reduced
heparan sulfate produced a normal fibronectin matrix but
failed to incorporate tenascin-C. Excess soluble
glycosaminoglycans inhibited the binding of tenascin-C to
purified fibronectin in ELISA, and completely blocked
incorporation into matrix fibrils. Treating cultured cells
with xyloside, which interferes with glycosaminoglycan
attachment to proteoglycans, also completely blocked their
ability to incorporate tenascin-C into matrix fibrils. We
conclude that proteoglycans bound to fibronectin fibrils
play a major role in binding tenascin-C to these fibrils. We
examined more closely the large heparan sulfate
proteoglycan, perlecan, and found that it co-localizes with
tenascin-C and fibronectin in the matrix. The perlecan
binding site in tenascin-C was mapped to the fibronectin
type III domains 3-5, but this binding was strongly enhanced
for the small splice variant, which is the major form
incorporated into the matrix. Apparently when the
alternative splice segment is inserted after domain 5 it
inhibits perlecan binding. Thus heparan sulfate
glycosaminoglycans, and perlecan in particular, may play a
role in incorporation of the small splice variant of
tenascin-C into fibronectin matrix fibrils.},
Key = {fds113206}
}
@article{fds113096,
Author = {T Ohashi and HP Erickson},
Title = {Two oligomeric forms of plasma ficolin have differential
lectin activity.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {272},
Number = {22},
Pages = {14220-6},
Year = {1997},
Month = {May},
ISSN = {0021-9258},
Keywords = {Animals • Binding Sites • Carrier Proteins •
Dimerization • Escherichia coli • Lectins •
Microscopy, Electron • Protein Conformation •
Swine • chemistry* • ultrastructure},
Abstract = {Ficolins are plasma proteins with binding activity for
carbohydrates, elastin, and corticosteroids. The ficolin
polypeptide has a collagen-like domain that presumably
brings three subunits together in a triple helical rod, a
C-terminal fibrinogen-like domain (fbg) similar to that of
tenascin, which presumably has the binding activities, and a
small N-terminal domain that we find to be the primary site
for forming the ficolin oligomer. By sedimentation
equilibrium we determined that the main plasma form, which
we call big ficolin, had mass of 827,000 Da, consistent with
24 subunits. Little ficolin, about half this size, was
obtained after binding to a GlcNAc affinity column. Electron
microscopy of little ficolin showed a parachute-like
structure, with a small globe at one end, corresponding to
the 12 N-terminal domains, and the fbg domains clustered
together at the ends of the collagen rods. Big ficolin was
formed by the face to face fusion of the fbg domains of two
little ficolins, leaving the rods and N-terminal domains
projecting at opposite ends. Little ficolin maintained a
high affinity for the GlcNAc column, and big ficolin had a
low affinity or none. The binding sites for ligands may be
obscured in this big ficolin oligomer, providing a
regulation of their activity.},
Key = {fds113096}
}
@article{fds113156,
Author = {RA Clark and HP Erickson and TA Springer},
Title = {Tenascin supports lymphocyte rolling.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {137},
Number = {3},
Pages = {755-65},
Year = {1997},
Month = {May},
ISSN = {0021-9525},
Keywords = {Binding Sites • Cell Adhesion • Cell Adhesion
Molecules • Cell Movement* • Cells, Cultured
• E-Selectin • Humans • Immunologic
Techniques • Integrins • Lymphocytes •
Rheology • Tenascin • Tonsil • chemistry
• cytology • cytology* • physiology •
physiology*},
Abstract = {Tenascin is a large extracellular matrix molecule expressed
at specific sites in the adult, including immune system
tissues such as the bone marrow, thymus, spleen, and T cell
areas of lymph nodes. Tenascin has been reported to have
both adhesive and anti-adhesive effects in static assays. We
report here that tenascin supports the tethering and rolling
of lymphocytes and lymphoblastic cell lines under flow
conditions. Binding was calcium dependent and was not
inhibited by treatment of lymphocytes with O-glycoprotease
or a panel of glycosidases including neuraminidase and
heparitinase but was inhibited by treatment of cells with
proteinase K. Binding was to the fibrinogen-like terminal
domain of tenascin as determined by antibody blocking
studies and binding to recombinant tenascin proteins. When
compared to rolling of the same cell type on E-selectin,
rolling on tenascin was found to be smoother at all shear
stresses tested, suggesting that cells formed a larger
number of bonds on the tenascin substrate than on the
E-selectin substrate. When protein plating densities were
adjusted to give similar profiles of cell detachment under
increasing shears, the density of tenascin was 8.5-fold
greater than that of E-selectin. Binding to tenascin was not
dependent on any molecules previously identified as tenascin
receptors and is likely to involve a novel tenascin receptor
on lymphocytes. We postulate that the ability of tenascin to
support lymphocyte rolling may reflect its ability to
support cell migration and that this interaction may be used
by lymphocytes migrating through secondary lymphoid
organs.},
Key = {fds113156}
}
@article{fds113163,
Author = {HP Erickson},
Title = {Stretching single protein molecules: titin is a weird
spring.},
Journal = {Science (New York, N.Y.), UNITED STATES},
Volume = {276},
Number = {5315},
Pages = {1090-2},
Year = {1997},
Month = {May},
ISSN = {0036-8075},
Keywords = {Amino Acid Sequence • Elasticity • Entropy •
Immunoglobulins • Muscle Proteins • Muscle
Relaxation • Muscle, Skeletal • Protein Folding*
• Protein Kinases • Sarcomeres • Stress,
Mechanical • chemistry • chemistry* •
physiology},
Key = {fds113163}
}
@article{fds113200,
Author = {DL Settles and M Kusakabe and DA Steindler and H Fillmore and HP
Erickson},
Title = {Tenascin-C knockout mouse has no detectable tenascin-C
protein.},
Journal = {Journal of neuroscience research, UNITED
STATES},
Volume = {47},
Number = {1},
Pages = {109-17},
Year = {1997},
Month = {January},
ISSN = {0360-4012},
Keywords = {Animals • Antibodies, Monoclonal • Blotting,
Western • Extracellular Matrix • Fluorescent
Antibody Technique • Immunoenzyme Techniques •
Mice • Mice, Knockout* • Phenotype •
Recombination, Genetic • Tenascin • chemistry
• genetics* • immunology • metabolism* •
physiology},
Abstract = {A recent study by Mitrovic and Schachner (J Neurosci Res
42:710-717, 1995) reported the detection of a small amount
of truncated tensacin-C (TN-C) in the nervous system of the
TN-C knockout mice created by Saga et al. (Genes Dev
6:1821-1831, 1992). The authors suggested that the truncated
protein might be responsible for the failure to detect any
phenotypic abnormalities in the knockout mice. We have
reexamined the knockout mice in our laboratories by Western
blot and immunocytochemistry, and have not detected any
full-length or truncated TN-C protein. In addition, we note
that the construction of the knockout gene deleted the
signal sequence, so if any residual truncated protein were
produced it would be trapped in the cytoplasm, and therefore
inaccessible to extracellular ligands or receptors. We
therefore conclude that the TN-C knockout created by Saga et
al. is a valid TN-C null.},
Key = {fds113200}
}
@article{fds113146,
Author = {ET O'Brien and ED Salmon and HP Erickson},
Title = {How calcium causes microtubule depolymerization.},
Journal = {Cell motility and the cytoskeleton},
Volume = {36},
Number = {2},
Pages = {125-35},
Year = {1997},
ISSN = {0886-1544},
url = {http://dx.doi.org/10.1002/(SICI)1097-0169(1997)36:2<125::AID-CM3>3.0.CO;2-8},
Keywords = {Animals • Biopolymers • Calcium •
Microtubule-Associated Proteins • Microtubules •
Sea Urchins • Swine • Tubulin • drug effects*
• pharmacology • pharmacology* •
ultrastructure},
Abstract = {The effects of calcium (Ca) were assessed using
video-enhanced differential interference contrast light
microscopy on individual microtubules in vitro.
Phosphocellulose-purified (PC) and microtubule associated
protein (MAP)-containing preparations of porcine brain
tubulin were assembled in a flow chamber onto sperm axoneme
fragments and the pattern of growth and shortening of the
microtubules was observed. Tubulin plus Ca was then added to
the chamber and observation continued. Ca promoted the
disassembly of microtubules by specifically promoting the
catastrophe reaction in both PC- and MAP-containing
microtubules, without an appreciable change in elongation
rate. The effect on catastrophe frequency increased very
rapidly above 0.5 mM free Ca, implying a possible
cooperative effect. The rescue rate remained very high after
Ca addition in MAP-containing microtubules, and the
shortening rate was unchanged, while in phosphocellulose-purified
microtubules, rescue appeared to be decreased by Ca addition
and shortening rates increased 4 to 6-fold. These results
illustrate that Ca can directly destabilize growing
microtubule ends without changing the effective
concentration of free tubulin, and that this effect can be
seen even against the background of the profound differences
in dynamics conferred by the microtubule-associated
proteins. Considered within models of the GTP cap, the
results imply that high Ca may act to increase the rate of
GTP hydrolysis within the cap.},
Language = {eng},
Doi = {10.1002/(SICI)1097-0169(1997)36:2<125::AID-CM3>3.0.CO;2-8},
Key = {fds113146}
}
@article{fds113133,
Author = {HP Erickson and D Stoffler},
Title = {Protofilaments and rings, two conformations of the tubulin
family conserved from bacterial FtsZ to alpha/beta and gamma
tubulin.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {135},
Number = {1},
Pages = {5-8},
Year = {1996},
Month = {October},
ISSN = {0021-9525},
Keywords = {Animals • Bacterial Proteins • Cytoskeletal
Proteins* • Microtubules • Polymers • Protein
Conformation* • Tubulin • chemistry •
chemistry* • ultrastructure*},
Key = {fds113133}
}
@article{fds113093,
Author = {EK LeMosy and VA Lightner and HP Erickson},
Title = {Structural analysis of a human glial variant
laminin.},
Journal = {Experimental cell research, UNITED STATES},
Volume = {227},
Number = {1},
Pages = {80-8},
Year = {1996},
Month = {August},
ISSN = {0014-4827},
Keywords = {Anion Exchange Resins • Astrocytes • Astrocytoma
• Cell Adhesion • Chromatography, Ion Exchange
• Electrophoresis, Gel, Two-Dimensional • Humans
• Keratan Sulfate • Laminin • Molecular
Weight • Protein Conformation • Proteochondroitin
Sulfates • Resins, Synthetic • Tumor Cells,
Cultured • chemistry* • cytology • isolation
& purification • methods • ultrastructure},
Abstract = {Astrocytes secrete laminin-like molecules in culture and may
represent a major source of laminin in the developing
central nervous system, yet these laminins have not been
extensively characterized. We previously reported the
presence of an astrocyte-derived variant laminin in media
conditioned by human U251 MG astrocytoma cells. This laminin
was partially purified in a highly anionic Mono Q fraction
with strong adhesion activity for fibroblasts and glial
cells (Aukhil et al. (1990) Matrix 10: 98-111). We now show
that glial laminin could be dissociated from an anionic
species, perhaps an approximately 400-kDa keratan sulfate
proteoglycan present in the preparation, by a second round
of Mono Q anion exchange chromatography in the presence of 6
M urea. Cell adhesion activity remained tightly associated
with laminin-containing fractions, suggesting that glial
laminin was responsible for the adhesion activity in the
original preparation. Immunochemical and SDS-PAGE gel
analyses of laminin heterotrimers demonstrated that glial
laminin contained the beta 2 and gamma 1 chains in
disulfide-bonded heterotrimeric complexes with a 360-kDa
chain, a 320-kDa chain, or a postulated approximately
200-kDa chain. While these chains were not recognized by
antibodies directed against the alpha 1-, alpha 2-, or alpha
3-related laminin chains, rotary shadowed glial laminin
molecules appeared to contain alpha chains, as judged by the
presence of an apparent G-domain terminating the long arm of
each laminin molecule. These findings suggest that glial
laminin contains one or more variant alpha chains, perhaps
related to one of the more recently described alpha chains,
alpha 3B, alpha 4, or alpha 5. Together our results
implicate human U251 MG glial laminin as a previously
uncharacterized laminin isoform with strong adhesive
activity for fibroblasts and glial cells.},
Key = {fds113093}
}
@article{fds113148,
Author = {CY Chung and JE Murphy-Ullrich and HP Erickson},
Title = {Mitogenesis, cell migration, and loss of focal adhesions
induced by tenascin-C interacting with its cell surface
receptor, annexin II.},
Journal = {Molecular biology of the cell, UNITED STATES},
Volume = {7},
Number = {6},
Pages = {883-92},
Year = {1996},
Month = {June},
ISSN = {1059-1524},
Keywords = {Animals • Annexin A2 • Antibodies • Cattle
• Cell Adhesion • Cell Division • Cell Line
• Cell Movement • Drug Interactions •
Endothelium, Vascular • Growth Substances •
Mitogens • Receptors, Cell Surface • Tenascin
• antagonists & inhibitors • biosynthesis* •
cytology • drug effects* • immunology •
pharmacology • pharmacology* •
physiology*},
Abstract = {In a previous study we demonstrated that the alternatively
spliced region of tenascin-C, TNfnA-D, bound with high
affinity to a cell surface receptor, annexin II. In the
present study we demonstrate three changes in cellular
activity that are produced by adding intact tenascin-C or
TNfnA-D to cells, and we show that all three activities are
blocked by antibodies against annexin II. 1) TNfnA-D added
to confluent endothelial cells induced loss of focal
adhesions. 2) TNfnA-D produced a mitogenic response of
confluent, growth-arrested endothelial cells in 1% serum.
TNfnA-D stimulated mitogenesis only when it was added to
cells before or during exposure to other mitogens, such as
basic fibroblast growth factor or serum. Thus the effect of
TNfnA-D seems to be to facilitate the subsequent response to
growth factors. 3) TNfnA-D enhanced cell migration in a cell
culture wound assay. Antibodies to annexin II blocked all
three cellular responses to TNfnA-D. These data show that
annexin II receptors on endothelial cells mediate several
cell regulatory functions attributed to tenascin-C,
potentially through modulation of intracellular signalling
pathways.},
Key = {fds113148}
}
@article{fds113176,
Author = {F Li and HP Erickson and JA James and KL Moore and RD Cummings and RP
McEver},
Title = {Visualization of P-selectin glycoprotein ligand-1 as a
highly extended molecule and mapping of protein epitopes for
monoclonal antibodies.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {271},
Number = {11},
Pages = {6342-8},
Year = {1996},
Month = {March},
ISSN = {0021-9258},
Keywords = {Amino Acid Sequence • Animals • Antibodies,
Monoclonal • CHO Cells • Cricetinae • Epitope
Mapping • Epitopes • Humans • Ligands •
Membrane Glycoproteins • Microscopy, Electron •
Molecular Sequence Data • P-Selectin • Recombinant
Fusion Proteins • genetics • immunology •
immunology* • metabolism* • ultrastructure •
ultrastructure*},
Abstract = {P-selectin glycoprotein ligand-1 (PSGL-1), a sialomucin on
human leukocytes, mediates rolling of leukocytes on
P-selectin expressed by activated platelets or endothelial
cells under shear forces. PSGL-1 requires both tyrosine
sulfate and O-linked glycans to bind P-selectin. Electron
microscopy of rotary-shadowed PSGL-1 purified from human
neutrophils indicated that it is a highly extended molecule
with an extracellular domain that is -50 nm long. Both
individual PSGL-1 molecules and rosettes composed of several
molecules presumably attached at their transmembrane
segments were observed. The extracellular domain of PSGL-1
has 318 residues, including a signal peptide from residues
1-18 and a propeptide from residues 19-41. Using bacterially
expressed fusion proteins and synthetic peptides derived
from the extracellular domain, we mapped the epitopes for
two IgG anti-PSGL-1 monoclonal antibodies, PL1 and PL2. PL2
bound to a region within residues 188-235 that is located in
a series of decameric consensus repeats. PL1, which blocks
binding of PSGL-1 to P-selectin, recognized an epitope
spanning residues 49-62. This sequence overlaps the tyrosine
sulfation sites at residues 46, 48, and 51 that have been
implicated in binding of PSGL-1 to P-selectin. Our results
demonstrate that PSGL-1 is a long, extended molecule and
suggest that the P-selectin binding site is located near the
N terminus, well above the membrane. This location may
facilitate interactions of PSGL-1 with P-selectin under
shear stress.},
Key = {fds113176}
}
@article{fds113099,
Author = {DL Settles and RA Cihak and HP Erickson},
Title = {Tenascin-C expression in dystrophin-related muscular
dystrophy.},
Journal = {Muscle & nerve, UNITED STATES},
Volume = {19},
Number = {2},
Pages = {147-54},
Year = {1996},
Month = {February},
ISSN = {0148-639X},
Keywords = {Animals • Blotting, Western • Dogs •
Dystrophin • Humans • Immunohistochemistry •
Mice • Mice, Inbred C57BL • Muscular Dystrophy,
Animal • Nerve Regeneration* • Tenascin •
Wound Healing* • analysis* • metabolism*},
Abstract = {The mdx mouse has a mutated dystrophin gene and is used as a
model for the study of Duchenne muscular dystrophy (DMD). We
investigated whether regenerating mdx skeletal muscle
contains the extracellular matrix protein tenascin-C (TN-C),
which is expressed in wound healing and nerve regeneration.
Prior to the initiation of muscle degeneration, both normal
and mdx mice displayed similar weak staining for TN-C in
skeletal muscle, but by 3 weeks of age the mice differed
substantially. TN-C was undetectable in normal muscle except
at the myotendinous junction, while in dystrophic muscle,
TN-C was prominent in degenerating/regenerating areas, but
absent from undegenerated muscle. With increasing age, TN-C
staining declined around stable regenerated mdx myofibers.
TN-C was also observed in muscle from dogs with muscular
dystrophy and in human boys with DMD. Therefore, in
dystrophic muscle, TN-C expression may be stimulated by the
degenerative process and remain upregulated unless the
tissue undergoes successful regeneration.},
Key = {fds113099}
}
@article{fds113193,
Author = {DJ Leahy and I Aukhil and HP Erickson},
Title = {2.0 A crystal structure of a four-domain segment of human
fibronectin encompassing the RGD loop and synergy
region.},
Journal = {Cell},
Volume = {84},
Number = {1},
Pages = {155-64},
Year = {1996},
Month = {January},
ISSN = {0092-8674},
Keywords = {Amino Acid Sequence • Crystallography •
Fibronectins • Humans • Image Processing,
Computer-Assisted • Molecular Sequence Data •
Oligopeptides • Protein Conformation • chemistry*
• ultrastructure},
Abstract = {We have determined the 2.0 A crystal structure of a fragment
of human fibronectin encompassing the seventh through the
RGD-containing tenth type III repeats (FN7-10). The
structure reveals an extended rod-like molecule with a long
axis of approximately 140 A and highly variable
relationships between adjacent domains. An unusually small
rotation between domains 9 and 10 creates a distinctive
binding site, in which the RGD loop from domain 10 and the
"synergy" region from domain 9 are on the same face of
FN7-10 and thus easily accessible to a single integrin
molecule. The cell-binding RGD loop is well-ordered in this
structure and extends approximately 10 A away from the
FN7-10 core.},
Language = {eng},
Key = {fds113193}
}
@article{fds113207,
Author = {HP Erickson and DW Taylor and KA Taylor and D Bramhill},
Title = {Bacterial cell division protein FtsZ assembles into
protofilament sheets and minirings, structural homologs of
tubulin polymers.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America},
Volume = {93},
Number = {1},
Pages = {519-23},
Year = {1996},
Month = {January},
ISSN = {0027-8424},
Keywords = {Animals • Bacterial Proteins • Cell Division
• Cytoskeletal Proteins* • Escherichia coli •
GTP-Binding Proteins • Guanosine Diphosphate •
Guanosine Triphosphate • Macromolecular Substances
• Microscopy, Electron • Microtubules •
Paclitaxel • Polymers • Protein Binding •
Scattering, Radiation • Swine • Tubulin •
chemistry • chemistry* • ultrastructure},
Abstract = {The bacterial cell division protein FtsZ is a homolog of
tubulin, but it has not been determined whether FtsZ
polymers are structurally related to the microtubule
lattice. In the present study, we have obtained
high-resolution electron micrographs of two FtsZ polymers
that show remarkable similarity to tubulin polymers. The
first is a two-dimensional sheet of protofilaments with a
lattice very similar to that of the microtubule wall. The
second is a miniring, consisting of a single protofilament
in a sharply curved, planar conformation. FtsZ minirings are
very similar to tubulin rings that are formed upon
disassembly of microtubules but are about half the diameter.
This suggests that the curved conformation occurs at every
FtsZ subunit, but in tubulin rings the conformation occurs
at either beta- or alpha-tubulin subunits but not both. We
conclude that the functional polymer of FtsZ in bacterial
cell division is a long thin sheet of protofilaments. There
is sufficient FtsZ in Escherichia coli to form a
protofilament that encircles the cell 20 times. The
similarity of polymers formed by FtsZ and tubulin implies
that the protofilament sheet is an ancient cytoskeletal
system, originally functioning in bacterial cell division
and later modified to make microtubules.},
Language = {eng},
Key = {fds113207}
}
@article{fds113158,
Author = {CY Chung and L Zardi and HP Erickson},
Title = {Binding of tenascin-C to soluble fibronectin and matrix
fibrils.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {270},
Number = {48},
Pages = {29012-7},
Year = {1995},
Month = {December},
ISSN = {0021-9258},
Keywords = {3T3 Cells • Animals • Cells, Cultured •
Chickens • Cricetinae • Extracellular Matrix
• Fibronectins • Glioma • Humans • Mice
• Protein Binding • RNA Splicing • Solubility
• Solutions • Tenascin • Tumor Cells,
Cultured • genetics • metabolism* •
pathology},
Abstract = {The small splice variant of tenascin-C (TN) has eight
fibronectin type III (FN3) domains. The major large splice
variant has three (in chicken) or seven (in human)
additional FN3 domains inserted between domains five and
six. Chiquet-Ehrismann et al. (Chiquet-Ehrismann, R.,
Matsuoka, Y., Hofer, U., Spring, J., Bernasconi, C., and
Chiquet, M. (1991, Cell Regul. 2, 927-938) demonstrated that
the small variant bound preferentially to fibronectin in
enzyme-linked immunosorbent assay, and only the small
variant was incorporated into the matrix by cultures of
chicken fibroblasts. Here we have studied human TN, and
confirmed that the small variant binds preferentially to
purified fibronectin and to fibronectin-containing
extracellular matrix. Thus this differential binding appears
to be conserved across vertebrate species. Using bacterial
expression proteins, we mapped the major binding site to the
third FN3 domain of TN. Consistent with this mapping, a
monoclonal antibody against an epitope in this domain did
not stain TN segments bound to cell culture matrix fibrils.
The enhanced binding of the small TN variant suggests the
existence of another, weak binding site probably in FN3
domains 6-8, which is only positioned to bind fibronectin in
the small splice variant. This binding of domains 6-8 may
involve a third molecule present in matrix fibrils, as the
enhanced binding of small TN was much more prominent to
matrix fibrils than to purified fibronectin.},
Key = {fds113158}
}
@article{fds113132,
Author = {T Qiao and BK Maddox and HP Erickson},
Title = {A novel alternative splice domain in zebrafish
tenascin-C.},
Journal = {Gene, NETHERLANDS},
Volume = {156},
Number = {2},
Pages = {307-8},
Year = {1995},
Month = {April},
ISSN = {0378-1119},
Keywords = {Alternative Splicing* • Amino Acid Sequence •
Animals • Cell Adhesion Molecules, Neuronal • DNA,
Complementary • Extracellular Matrix Proteins •
Gene Library • Molecular Sequence Data • Sequence
Analysis, DNA • Sequence Homology • Tenascin
• Zebrafish • genetics • genetics*},
Abstract = {We have identified and sequenced clones from a zebrafish
library that correspond to tenascin-C (TN-C). The 2036-bp
sequence covers the C-terminal segment of the protein.
Comparison of this sequence to TN-C from other vertebrates
indicates that our sequence starts in FN-III domain 5,
continues with one alternative splice domain, then with
FN-III domains 6-8 and, finally, the complete
fibrinogen-like domain. The alternative splice domain,
designated TNfnQ, is not closely identified to any of the
domains in other species, and may represent a novel
descendent of the alternative splice-domain
precursor.},
Key = {fds113132}
}
@article{fds113170,
Author = {DA Steindler and D Settles and HP Erickson and ED Laywell and A Yoshiki and A Faissner and M Kusakabe},
Title = {Tenascin knockout mice: barrels, boundary molecules, and
glial scars.},
Journal = {The Journal of neuroscience : the official journal of the
Society for Neuroscience, UNITED STATES},
Volume = {15},
Number = {3 Pt 1},
Pages = {1971-83},
Year = {1995},
Month = {March},
ISSN = {0270-6474},
Keywords = {Animals • Brain Injuries • Brain Mapping* •
Cell Adhesion Molecules, Neuronal • Electron Transport
Complex IV • Extracellular Matrix Proteins • Mice
• Mice, Knockout • Proteoglycans •
Somatosensory Cortex • Tenascin • Vibrissae •
analysis • anatomy & histology* • cytology •
diagnostic use • metabolism • metabolism* •
pathology},
Abstract = {In light of a previous report suggesting that the brains of
tenascin-deficient animals are grossly normal, we have
studied the somatosensory cortical barrel field and injured
cerebral cortex in postnatal homozygous tenascin knockout,
heterozygote, and normal wild-type mice. Nissl staining,
cytochrome oxidase, and Dil axonal tracing of
thalamocortical axonal projections to the somatosensory
cortex, all reveal the formation of normal barrels in the
first postnatal week in homozygous knockout mice that cannot
be distinguished from heterozygote or normal wild-type
barrels. In addition to confirming the absence of tenascin
in knockout animals, and reporting apparently reduced levels
of the glycoprotein in barrel boundaries of heterozygote
animals using well-characterized antibodies and
immunocytochemistry, we also studied the DSD-1-PG
proteoglycan, another developmentally regulated molecule
known to be associated with transient glial/glycoconjugate
boundaries that surround developing barrels; DSD-1-PG was
also found to be expressed in barrel boundaries in
apparently normal time frames in tenascin knockout mice.
Peanut agglutinin (PNA) binding of galactosyl-containing
glycoconjugates also revealed barrel boundaries in all three
genotypes. We also examined the expression of tenascin-R, a
paralog of tenascin-C (referred to here simply as tenascin).
As previously reported, tenascin-R is prominently expressed
in subcortical white matter, and we found it was not
expressed in the barrel boundaries in any of the genotypes.
Thus, the absence of tenascin does not result in a
compensatory expression of tenascin-R in the barrel
boundaries. Finally, we studied wounds of the cerebral
cortex in the late postnatal mouse. The astroglial scar
formed, for the most part, in the same time course and
spatial distribution in the wild-type and tenascin knockout
mice. However, there may be some differences in the extent
of gliosis between the knockout and the wild type that
warrant further study. Roles for boundary molecules like
tenascin during brain pattern formation and injury are
reconsidered in light of these findings on barrel
development and cortical lesions in tenascin-deficient
mice.},
Key = {fds113170}
}
@article{fds113166,
Author = {HP Erickson},
Title = {FtsZ, a prokaryotic homolog of tubulin?},
Journal = {Cell, UNITED STATES},
Volume = {80},
Number = {3},
Pages = {367-70},
Year = {1995},
Month = {February},
ISSN = {0092-8674},
Keywords = {Animals • Bacteria • Bacterial Proteins •
Base Sequence • Cell Division • Cytoskeletal
Proteins* • GTP-Binding Proteins • Molecular
Sequence Data • Sequence Homology, Amino Acid •
Tubulin • chemistry • chemistry* • cytology
• metabolism* • physiology*},
Key = {fds113166}
}
@article{fds113167,
Author = {PL Jones and N Boudreau and CA Myers and HP Erickson and MJ
Bissell},
Title = {Tenascin-C inhibits extracellular matrix-dependent gene
expression in mammary epithelial cells. Localization of
active regions using recombinant tenascin
fragments.},
Journal = {Journal of cell science, ENGLAND},
Volume = {108 ( Pt 2)},
Pages = {519-27},
Year = {1995},
Month = {February},
ISSN = {0021-9533},
Keywords = {Animals • Caseins • Cell Adhesion Molecules,
Neuronal • Cell Line • Epithelium •
Extracellular Matrix • Extracellular Matrix Proteins
• Gene Expression Regulation* • Laminin •
Mammary Glands, Animal • Mice • Milk Proteins
• Peptide Fragments • Protein Synthesis Inhibitors
• Recombinant Proteins • Tenascin •
Transcription, Genetic • biosynthesis • chemistry
• genetics • metabolism • metabolism* •
pharmacology • physiology*},
Abstract = {The physiological role of tenascin in vivo has remained
obscure. Although tenascin is regulated in a stage and
tissue-dependent manner, knock-out mice appear normal. When
tenascin expression was examined in the normal adult mouse
mammary gland, little or none was present during lactation,
when epithelial cells actively synthesize and secrete milk
proteins in an extracellular matrix/lactogenic
hormone-dependent manner. In contrast, tenascin was
prominently expressed during involution, a stage
characterized by the degradation of the extracellular matrix
and the subsequent loss of milk production. Studies with
mammary cell lines indicated that tenascin expression was
high on plastic, but was suppressed in the presence of the
laminin-rich, Engelbreth-Holm-Swarm (EHS) tumour biomatrix.
When exogenous tenascin was added together with EHS to
mammary epithelial cells, beta-casein protein synthesis and
steady-state mRNA levels were inhibited in a
concentration-dependent manner. Moreover, this inhibition by
tenascin could be segregated from its effects on cell
morphology. Using two beta-casein promoter constructs
attached to the chloramphenicol acetyltransferase reporter
gene we showed that tenascin selectively suppressed
extracellular matrix/prolactin-dependent transcription of
the beta-casein gene in three-dimensional cultures. Finally,
we mapped the active regions within the fibronectin type III
repeat region of the tenascin molecule that are capable of
inhibiting beta-casein protein synthesis. Our data are
consistent with a model where both the loss of a
laminin-rich basement membrane by extracellular
matrix-degrading enzymes and the induction of tenascin
contribute to the loss of tissue-specific gene expression
and thus the involuting process.},
Key = {fds113167}
}
@article{fds113152,
Author = {HP Erickson},
Title = {Reversible unfolding of fibronectin type III and
immunoglobulin domains provides the structural basis for
stretch and elasticity of titin and fibronectin.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America},
Volume = {91},
Number = {21},
Pages = {10114-8},
Year = {1994},
Month = {October},
ISSN = {0027-8424},
Keywords = {Calorimetry • Elasticity • Fibronectins •
Immunoglobulins • Kinesin • Membrane Proteins
• Models, Structural • Muscle Proteins •
Myosins • Protein Conformation* • Protein
Denaturation • Protein Folding* • Protein Kinases*
• Protein Structure, Secondary* • chemistry •
chemistry* • metabolism},
Abstract = {The elastic protein titin comprises a tandem array of
fibronectin type III and immunoglobulin domains, which are
structurally similar 7-strand beta-sandwiches. A proposed
mechanism for stretching titin, by sequential denaturation
of individual fibronectin type III-immunoglobulin domains in
response to applied tension, is analyzed here
quantitatively. The folded domain is approximately 4 nm
long, and the unraveled polypeptide can extend to 29 nm,
providing a 7-fold stretch over the relaxed length. Elastic
recoil is achieved by refolding of the denatured domains
when the force is released. The critical force required to
denature a domain is calculated to be 3.5-5 pN, based on a
net free energy for denaturation of 7-14 kcal/mol, plus 5
kcal/mol to extend the polypeptide (1 cal = 4.184 J). This
force is comparable to the 2- to 7-pN force generated by
single myosin or kinesin molecules. The force needed to pull
apart a noncovalent protein-protein interface is estimated
here to be 10-30 pN, implying that titin will stretch
internally before the molecule is pulled from its attachment
at the Z band. Many extracellular matrix and cell adhesion
molecules, such as fibronectin, contain tandem arrays of
fibronectin type III domains. Both single molecules and
matrix fibers should have elastic properties similar to
titin.},
Language = {eng},
Key = {fds113152}
}
@article{fds113168,
Author = {C Sadhu and B Lipsky and HP Erickson and J Hayflick and KO Dick and WM
Gallatin, DE Staunton},
Title = {LFA-1 binding site in ICAM-3 contains a conserved motif and
non-contiguous amino acids.},
Journal = {Cell adhesion and communication, SWITZERLAND},
Volume = {2},
Number = {5},
Pages = {429-40},
Year = {1994},
Month = {October},
ISSN = {1061-5385},
Keywords = {Amino Acid Sequence • Animals • Antibodies,
Monoclonal • Antigens, CD* • Antigens,
Differentiation* • Base Sequence • Binding Sites
• Cell Adhesion Molecules • Cell Line •
Cercopithecus aethiops • Conserved Sequence •
Epitopes • Lymphocyte Function-Associated Antigen-1
• Mice • Mice, Inbred BALB C • Microscopy,
Electron • Molecular Sequence Data • Mutagenesis,
Site-Directed • Protein Structure, Secondary* •
Recombinant Fusion Proteins • Sequence Deletion •
Transfection • analysis • chemistry •
chemistry* • immunology • metabolism •
metabolism* • ultrastructure},
Abstract = {The intercellular adhesion molecule-3 (ICAM-3) is a counter
receptor for the integrin LFA-1 that supports cell-cell
adhesion dependent functions. ICAM-3 is a member of the
immunoglobulin superfamily possessing five
immunoglobulin-like domains. Here, we characterize the
overall shape of ICAM-3 and the amino acid residues involved
in binding LFA-1 and monoclonal antibodies (Mab). Electron
microscopic observations show that ICAM-3 is predominantly a
straight rod of 15 nm in length, suggesting a head to tail
arrangement of the immunoglobulin-like domains. Six out of
nine ICAM-3 Mab described blocked the interaction with LFA-1
to varying degrees. Domain assignment of blocking Mab
epitopes and characterization of LFA-1-dependent cell
adhesion to ICAM-3 mutants demonstrate that the
amino-terminal domain of ICAM-3 interacts with LFA-1. A
conserved amino acid motif including residues E37 and T38
form an integrin binding site (IBS) in ICAM-3. This motif
has also been shown to function as an IBS in ICAM-3 and
VCAM-1 and hence many form a common site of contact in all
CAMs of this type. Other ICAM-3 residues critical to
adhesive interactions, such as Q75, conserved in ICAM-1 and
ICAM-2, but not VCAM-1, may confer specificity to LFA-1
binding. This residue, Q75, is predicted to locate in a
model of ICAM-3 to the same site as RGD in the
immunoglobulin-like domain of fibronectin that binds several
integrins. This suggest an evolutionary relationship between
ICAMs and fibronectin interactions with integrins.},
Key = {fds113168}
}
@article{fds113087,
Author = {CY Chung and HP Erickson},
Title = {Cell surface annexin II is a high affinity receptor for the
alternatively spliced segment of tenascin-C.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {126},
Number = {2},
Pages = {539-48},
Year = {1994},
Month = {July},
ISSN = {0021-9525},
Keywords = {Alternative Splicing* • Amino Acid Sequence •
Animals • Annexin A2 • Binding Sites • Cattle
• Cell Adhesion Molecules, Neuronal • Cells,
Cultured • Endothelium • Extracellular Matrix
Proteins • Glioma • Humans • Kinetics •
Lung • Molecular Sequence Data • Nerve Tissue
Proteins • Radioligand Assay • Receptors, Cell
Surface • Recombinant Proteins • Sequence Analysis
• Tenascin • Tumor Cells, Cultured •
chemistry • cytology • genetics • isolation &
purification • metabolism • metabolism*},
Abstract = {We have investigated the binding of soluble tenascin-C
(TN-C) to several cell lines using a radioligand binding
assay. Specific binding was demonstrated to U-251MG human
glioma cells and to a line of bovine aortic endothelial
cells, but hamster fibroblasts showed no specific binding.
Recombinant proteins corresponding to specific domains of
TN-C were used to map the binding site(s) in TN-C. The
alternatively spliced segment (TNfnA-D) inhibited the
binding of native TN-C most strongly, and itself bound to
glioma and endothelial cells. Scatchard analysis of TNfnA-D
binding indicated 2-5 x 10(5) binding sites per cell, with
an apparent 2 nM dissociation constant. The cell surface
receptor for TNfnA-D was identified as a 35-kD protein on
the basis of blot binding assays and affinity chromatography
of membrane extracts on native TN-C and TNfnA-D columns.
Protein sequencing indicated that this 35-kD receptor was
annexin II. Annexin II is well characterized as a
cytoplasmic protein, so it was surprising to find it as a
presumably extracellular receptor for TN-C. To confirm that
it was the 35-kD receptor, we obtained purified annexin II
and demonstrated its binding to TNfnA-D and TN-C at nM
concentrations. Antibodies to annexin II prominently stained
the external surface of live endothelial cells and blocked
the binding of TNfnA-D to the cells. Thus annexin II appears
to be a receptor for the alternatively spliced segment of
TN-C, and may mediate cellular responses to soluble TN-C in
the extracellular matrix.},
Key = {fds113087}
}
@article{fds113129,
Author = {DJ Leahy and HP Erickson and I Aukhil and P Joshi and WA
Hendrickson},
Title = {Crystallization of a fragment of human fibronectin:
introduction of methionine by site-directed mutagenesis to
allow phasing via selenomethionine.},
Journal = {Proteins, UNITED STATES},
Volume = {19},
Number = {1},
Pages = {48-54},
Year = {1994},
Month = {May},
ISSN = {0887-3585},
Keywords = {Amino Acid Sequence • Crystallization •
Crystallography, X-Ray • Fibronectins • Humans
• Methionine* • Molecular Sequence Data •
Mutagenesis, Site-Directed • Peptide Fragments •
Protein Structure, Tertiary • Selenomethionine* •
chemistry • chemistry*},
Abstract = {Crystals of a fragment of human fibronectin encompassing the
7th through the RGD-containing 10th type III repeats
(FN7-10) have been produced with protein expressed in E.
coli. The crystals are monoclinic with one molecule in the
asymmetric unit and diffract to beyond 2.0 A Bragg spacings.
A mutant FN7-10 was produced in which three methionines, in
addition to the single native methionine already present,
have been introduced by site-directed mutagenesis.
Diffraction-quality crystals of this mutant protein have
been grown in which methionine was replaced with
selenomethionine. The introduction of methionine by
site-directed mutagenesis to allow phasing from
selenomethionyl-substituted crystals is shown to be feasible
by this example and is proposed as a general approach to
solving the crystallographic phase problem. Strategies for
selecting propitious sites for methionine mutations are
discussed.},
Key = {fds113129}
}
@article{fds113113,
Author = {J Julian and R Chiquet-Ehrismann and HP Erickson and DD
Carson},
Title = {Tenascin is induced at implantation sites in the mouse
uterus and interferes with epithelial cell
adhesion.},
Journal = {Development (Cambridge, England), ENGLAND},
Volume = {120},
Number = {3},
Pages = {661-71},
Year = {1994},
Month = {March},
ISSN = {0950-1991},
Keywords = {Animals • Cell Adhesion • Cell Adhesion Molecules,
Neuronal • Embryo Implantation • Epithelium •
Estrus • Extracellular Matrix • Extracellular
Matrix Proteins • Female • Immunohistochemistry
• Mice • Mice, Inbred Strains • Pregnancy
• Tenascin • Uterus • physiology •
physiology*},
Abstract = {Expression of tenascin, an extracellular matrix protein
associated with morphogenetic events and altered states of
cellular adhesion, was examined in mouse uterus during the
peri-implantation period. A uniform low level expression of
tenascin was detected in stromal extracellular matrix during
the estrous cycle and days 1 through 4 of early pregnancy.
During the period of blastocyst attachment (day 4.5), an
intense deposition of tenascin fibrils was located in the
extracellular matrix of stroma immediately subjacent to the
uterine epithelium surrounding the attaching blastocyst.
This localized intensity of tenascin expression was both
spatially and temporally restricted. By day 5.5,
differentiation of stroma in the immediate area around the
embryo to form the primary decidual zone was accompanied by
a reduced amount of tenascin expression in the form of
fragmented fibrils. Tenascin also could be induced by an
artificial stimulus in uterine stroma of mice that had been
hormonally prepared for implantation. The ability of
artificial stimuli to induce tenascin expression suggested
that the tenascin-inducing signals were derived from uterine
cells, presumably lumenal epithelium, rather than embryonic
cells. Consistent with this, conditioned medium from primary
cultures of uterine epithelium was found to induce tenascin
expression (2- to 4-fold) in isolated uterine stroma.
Artificial stimuli generated a temporal pattern of tenascin
expression similar to that observed during early pregnancy;
however, in the artificially induced model, tenascin was
induced in stroma immediately subjacent to lumenal
epithelium along the entire length of the uterus. Purified
tenascin and a recombinant tenascin fragment consisting of
alternatively spliced fibronectin type III repeats,
interfered with maintenance of uterine epithelial cell
adhesion to Matrigel. In contrast, other recombinant
tenascin fragments or fibronectin had no effect in this
regard. Tenascin had no effect on adhesion of uterine
stroma. Collectively, these results suggest that stimulation
of TN expression in stromal extracellular matrix in vivo
occurs via hormonally regulated, epithelial-mesenchymal
interactions and serves as an early marker for uterine
receptivity and the attachment phase of implantation.
Furthermore, tenascin may facilitate embryo penetration by
disrupting uterine epithelial cell adhesion to underlying
basal lamina.},
Key = {fds113113}
}
@article{fds113077,
Author = {SL Young and LY Chang and HP Erickson},
Title = {Tenascin-C in rat lung: distribution, ontogeny and role in
branching morphogenesis.},
Journal = {Developmental biology, UNITED STATES},
Volume = {161},
Number = {2},
Pages = {615-25},
Year = {1994},
Month = {February},
ISSN = {0012-1606},
Keywords = {Age Factors • Animals • Cell Adhesion Molecules,
Neuronal • Culture Techniques • Extracellular
Matrix Proteins • Female • Lung • Microscopy,
Immunoelectron • Morphogenesis • Pregnancy •
Rats • Rats, Sprague-Dawley • Tenascin •
analysis* • chemistry* • growth & development
• immunology • physiology},
Abstract = {Extracellular matrix is important to organogenesis and may
function by modifying cellular adhesion, motility,
proliferation, and differentiation. Tenascin-C (TN-C) is a
matrix molecule reported to bind some cell lines and to
inhibit adhesion of some cell types to fibronectin. This
report describes the ontogeny and possible functions of TN-C
expression in fetal and newborn rat lung. There was a
moderate concentration of TN-C protein at the
epithelial-mesenchymal interface during fetal lung
development in the period of branching morphogenesis. There
was a remarkable accumulation of TN-C during the first
postnatal week when alveolarization peaked, followed by a
decline to barely detectable levels after the third
postnatal week when alveolarization was essentially
completed. Loss of TN-C protein followed quickly the loss of
TN-C mRNA, suggesting a rapid turnover of TN-C in the
extracellular matrix. By light microscopy, immunoreactive
TN-C was present in early postnatal lung at the
epithelial-mesenchymal interface and was distributed
throughout lung mesenchyme. Electron microscopic
immunocytochemistry showed TN-C was not a part of the basal
lamina and that its lung localization was punctate and
different from the uniform distribution of laminin.
Antiserum to TN-C significantly inhibited branching
morphogenesis of fetal lung explants but did not block their
growth. Three bacterially expressed segments of TN-C
comprising different fibronectin type III domains inhibited
branching morphogenesis as effectively as did antiserum, but
an expression protein of the carboxyterminal fibrinogen-like
segment had no effect. We conclude that TN-C is expressed in
a spatio-temporal pattern consistent with a role in lung
development and our in vitro studies indicated a functional
role for TN-C during lung branching morphogenesis.},
Key = {fds113077}
}
@article{fds113189,
Author = {WJ Rettig and HP Erickson and AP Albino and P Garin-Chesa},
Title = {Induction of human tenascin (neuronectin) by growth factors
and cytokines: cell type-specific signals and signalling
pathways.},
Journal = {Journal of cell science, ENGLAND},
Volume = {107 ( Pt 2)},
Pages = {487-97},
Year = {1994},
Month = {February},
ISSN = {0021-9533},
Keywords = {Cell Adhesion Molecules, Neuronal • Cell Line •
Cycloheximide • Cytokines • Dactinomycin •
Extracellular Matrix Proteins • Fetus •
Fibroblasts • Growth Substances • Humans •
Melanocytes • Nerve Tissue Proteins • Neurons
• Organ Specificity • Platelet-Derived Growth
Factor • Signal Transduction • Tenascin •
Transforming Growth Factor beta • biosynthesis* •
drug effects • metabolism • pharmacology •
pharmacology*},
Abstract = {The extracellular matrix protein tenascin (TN) is expressed
with precise temporo-spatial patterns during embryonic and
fetal development and is induced in healing wounds,
inflammatory lesions and solid tumors. These tissue patterns
suggest that TN synthesis may be modulated by soluble
factors present in developing tissues or released from
injured, inflammatory or neoplastic cells. To characterize
the extrinsic control of human TN we examined the effects of
several signalling molecules on cultured neural, melanocytic
and fibroblastic cells. Results obtained with alpha TN
antibodies in enzyme-linked immunosorbent and
immunoprecipitation assays indicate that TN expression is
tightly regulated in a cell type-specific manner: (1)
Primitive neuroectodermal tumor (PNET) cells grown in
chemically defined, serum-free media show up to > 100-fold
TN induction in response to fibroblast growth factors (aFGF,
bFGF, K-FGF) and phorbol ester, independent of changes in
cell proliferation or total protein synthesis; no induction
is seen in PNET cultures stimulated with serum or other
growth and differentiation factors. (2) Normal melanocytes,
which require FGF and phorbol ester for survival in vitro,
fail to express TN; however, they produce TN following
oncogenic transformation. (3) Fibroblasts derived from
disparate tissues differ up to 100-fold in basal TN
production; for example, fetal lung fibroblasts are TNhigh,
but conjunctival fibroblasts derived from the same donors
and fetal leptomeningeal cells are TNlow. (4) TNlow
fibroblasts treated with interleukin-1, tumor necrosis
factor-alpha, and interleukin-4 show up to > 100-fold
increased TN secretion and TN incorporation into their
extracellular matrix. Transforming growth factor-beta, which
acts as an inducer of fibronectin, collagen, and
integrin-type matrix receptors, has variable effects on
fibroblast TN, ranging from increased deposition in the
extracellular matrix of fetal conjunctival fibroblasts to
reduced secretion in newborn foreskin fibroblasts. In
contrast, FGFs (which are potent fibroblast mitogens),
phorbol ester, bone morphogenetic proteins, and several
other factors tested produced no discernible effects on
fibroblast TN expression. These findings suggest that
discrete sets of extrinsic signals modify TN expression in
specific cell types, with the effects of a given
ligand/receptor system determined by cell type-specific
signalling pathways that may be linked to unique
cis-regulatory elements of the TN gene. As a result, a
limited set of regulatory peptides may produce highly
diversified TN distribution patterns in developing and
lesional tissues.},
Key = {fds113189}
}
@article{fds113213,
Author = {HP Erickson},
Title = {Evolution of the tenascin family--implications for function
of the C-terminal fibrinogen-like domain.},
Journal = {Perspectives on developmental neurobiology, UNITED
STATES},
Volume = {2},
Number = {1},
Pages = {9-19},
Year = {1994},
ISSN = {1064-0517},
Keywords = {Animals • Cell Adhesion Molecules, Neuronal •
Extracellular Matrix Proteins • Fibrinogen •
Growth Substances • Humans • Mice • Mice,
Knockout • Molecular Sequence Data • Multigene
Family* • Mutation • Phylogeny* • Protein
Structure, Tertiary* • Sequence Homology, Amino Acid
• Species Specificity • Structure-Activity
Relationship • Tenascin • Time Factors •
Vertebrates • chemistry • genetics* •
physiology},
Abstract = {The three members of the tenascin (TN) family, TN-C, TN-R,
and TN-X, are apparently conserved in all vertebrates and
therefore must have functions that contribute to survival.
One specific domain of tenascins, the fibrinogen-like
terminal knob, can be argued to have an essential function.
Its position at the C-terminus makes it most vulnerable to
loss through mutation or deletion, and it should have been
eliminated in evolution if there were no selective pressure
to maintain it. The epidermal growth factor and fibronectin
III domains probably play an important role as spacers,
placing the terminal knob at the end of the tribrachion or
hexabrachion arms. In addition to functioning as spacers, at
least some of these domains may have additional functional
interactions. The conservation of these domains in evolution
is comparable to that of some growth factors, consistent
with this possibility. A phylogenetic tree of all known
fibrinogen-related domains, including those in tenascins, is
presented.},
Key = {fds113213}
}
@article{fds113180,
Author = {G Perides and HP Erickson and F Rahemtulla and A Bignami},
Title = {Colocalization of tenascin with versican, a
hyaluronate-binding chondroitin sulfate proteoglycan.},
Journal = {Anatomy and embryology, GERMANY},
Volume = {188},
Number = {5},
Pages = {467-79},
Year = {1993},
Month = {November},
ISSN = {0340-2061},
Keywords = {Animals • Brain • Brain Chemistry* • Cattle
• Cell Adhesion Molecules, Neuronal •
Extracellular Matrix Proteins • Fluorescent Antibody
Technique • Humans • Lectins, C-Type •
Proteochondroitin Sulfates • Rats • Rats,
Sprague-Dawley • Species Specificity • Spinal Cord
• Tenascin • Versicans • analysis* •
chemistry* • embryology • growth &
development},
Abstract = {Rabbit antisera against tenascin, a large extracellular
matrix protein, in conjunction with monoclonal antibodies of
mouse origin against versican, a large hyaluronate-binding
proteoglycan, were used to make a comparative study of the
distribution of the two antigens in the same cryostat
sections by double immunofluorescence. In the central
nervous system, tenascin was invariably associated with
versican, but the reverse was not true, in that versican was
also found where tenascin was not detectable, particularly
in gray matter. There were major species differences in the
distribution of tenascin in the central nervous system. In
the cow, tenascin was found in cerebral and spinal cord
white matter and in the granule cell layer of the
cerebellum. In the human brain, tenascin was found in
cerebral white matter but not in the cerebellum. In the rat,
tenascin was mainly confined to brain periventricular layer
and spinal cord white matter. During the development of the
cerebellum of the rat, the tenascin immunoreactivity
decreased, and a lower molecular weight band appeared
(J1-160/180/restrictin?) and persisted throughout adulthood.
Tenascin expression was a relatively late event in the
development of the rat central nervous system,
immunoreactivity being first observed after birth. In the
rat embryo, tenascin was found to co-localize with versican
in precartilaginous mesenchyme and in connective tissue
underlying epithelia. The colocalization of versican with
tenascin suggests that versican may be the tenascin
(cytotactin)-associated proteoglycan reported in the
literature.},
Key = {fds113180}
}
@article{fds113217,
Author = {HP Erickson},
Title = {Tenascin-C, tenascin-R and tenascin-X: a family of talented
proteins in search of functions.},
Journal = {Current opinion in cell biology, UNITED STATES},
Volume = {5},
Number = {5},
Pages = {869-76},
Year = {1993},
Month = {October},
ISSN = {0955-0674},
Keywords = {Adult • Animals • Cell Adhesion Molecules,
Neuronal • Drosophila • Extracellular Matrix
• Extracellular Matrix Proteins • Humans •
Mice • Neoplasms • Phylogeny • Tenascin
• Wound Healing • chemistry • genetics •
metabolism • physiology • physiology*},
Abstract = {"Mice develop normally without tenascin", was a shock to
biologists studying the extracellular matrix. Could tenascin
be a useless protein? This seems most improbable, as it is
conserved in every vertebrate species. Moreover, two new
proteins have been discovered in the last year that are
closely related to the original tenascin, providing evidence
for a tenascin family. Speculations on functions are ripe
for re-evaluation.},
Key = {fds113217}
}
@article{fds113198,
Author = {P Joshi and CY Chung and I Aukhil and HP Erickson},
Title = {Endothelial cells adhere to the RGD domain and the
fibrinogen-like terminal knob of tenascin.},
Journal = {Journal of cell science, ENGLAND},
Volume = {106 ( Pt 1)},
Pages = {389-400},
Year = {1993},
Month = {September},
ISSN = {0021-9533},
Keywords = {Amino Acid Sequence • Animals • Cations, Divalent
• Cattle • Cell Adhesion • Cell Adhesion
Molecules, Neuronal • Cells, Cultured • Collodion
• Cricetinae • Culture Techniques •
Endothelium • Endothelium, Vascular • Epithelium
• Extracellular Matrix Proteins • Fibrinogen
• Fibroblasts • Humans • Immune Sera •
Integrins • Mice • Molecular Sequence Data •
Oligopeptides • Plastics • Rats • Receptors,
Cytoadhesin • Receptors, Vitronectin • Tenascin
• chemistry • immunology • instrumentation
• metabolism • metabolism* • pharmacology
• physiology},
Abstract = {We have found that endothelial cells adhere much more
strongly than fibroblasts to domains of tenascin and
fibronectin. Endothelial cells adhered weakly, without
spreading, to bacterial expression proteins corresponding to
the tenth fibronectin type III (FN-III) domain of
fibronectin, which contains the RGD. A larger fibronectin
protein, containing this domain and the three amino-terminal
'synergy' domains gave strong adhesion and spreading. Two
widely separated domains of tenascin gave adhesion. The
third FN-III domain, TNfn3, which contains an RGD sequence
in human and chicken tenascin, gave very strong adhesion and
spreading of endothelial cells when tested as an isolated
domain. Larger segments containing TNfn3 and the adjacent
TNfn2 gave weaker adhesion, probably because the RGD
sequence is partially blocked. Adhesion to this domain
required divalent cations, was exquisitely sensitive to
soluble GRGDSP peptide, and was blocked by antisera to the
integrin alpha v beta 3. The second tenascin adhesion domain
was the fibrinogen-like C-terminal knob, TNfbg. Cells
adhered to but did not spread on this domain. This adhesion
required divalent cations and was also sensitive to GRGDSP
peptide, so it may be mediated by an integrin receptor. We
have explored a range of conditions for preparing the
adhesion substratum, and our results may resolve the
controversy over whether tenascin can act as a substratum
adhesion molecule. When coated for short times (1-2 hours)
on plastic, tenascin had no adhesion activity, in contrast
to fibronectin and the expression proteins, which gave
strong adhesion under these conditions. When coated for
longer times (12-24 hours) on plastic, the tenascin
substratum supported good adhesion, but not spreading, of
endothelial cells. Tenascin coated on nitrocellulose gave
substantially stronger adhesion than on plastic, but still
required long coating times for maximal activity. Adhesion
of endothelial cells to native TN was inhibited by GRDGSP
peptide. The cell adhesion activity demonstrates the
presence on endothelial cells of tenascin receptors, which
may play a supportive role in angiogenesis, in the structure
of blood vessels, or in binding tenascin to the cell surface
to elicit or enhance a signalling function.},
Key = {fds113198}
}
@article{fds113153,
Author = {S Ushiyama and TM Laue and KL Moore and HP Erickson and RP
McEver},
Title = {Structural and functional characterization of monomeric
soluble P-selectin and comparison with membrane
P-selectin.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {268},
Number = {20},
Pages = {15229-37},
Year = {1993},
Month = {July},
ISSN = {0021-9258},
Keywords = {Alternative Splicing • Amino Acid Sequence • Base
Sequence • Binding Sites • Cell Adhesion •
Cell Adhesion Molecules • Cells, Cultured • DNA
• Humans • Microscopy, Electron • Molecular
Sequence Data • Neutrophils • P-Selectin •
Platelet Membrane Glycoproteins • Protein Conformation
• Recombinant Proteins • Solubility •
chemistry • isolation & purification • metabolism
• physiology* • ultrastructure},
Abstract = {P-selectin is an adhesion receptor for leukocytes on
thrombin-activated platelets and endothelial cells. It
contains a NH2-terminal carbohydrate-recognition domain, an
epidermal growth factor motif, nine consensus repeats, a
transmembrane domain, and a cytoplasmic tail. We expressed
two soluble forms of P-selectin, one truncated after the
ninth repeat (tPS) and the other lacking the transmembrane
domain due to alternative RNA splicing (asPS). When
visualized by electron microscopy, each was a monomeric
rod-like structure with a globular domain at one end,
whereas membrane P-selectin (mPS) from platelets formed
rosettes with the globular domains facing outward.
Sedimentation velocity and equilibrium studies confirmed
that tPS and asPS were asymmetric monomers, whereas mPS was
oligomeric. HL-60 cells adhered to immobilized tPS and asPS,
although less efficiently than to mPS. 125I-Labeled tPS and
asPS bound to approximately 25,000 sites/neutrophil and
approximately 36,000 sites/HL-60 cell with an apparent Kd of
70 nM. Treatment of HL-60 cells with O-sialoglycoprotease
eliminated the binding sites for asPS. We conclude that 1)
P-selectin is a rigid, asymmetric protein; 2) monomeric
soluble P-selectin binds to high affinity ligands with
sialylated O-linked oligosaccharides on leukocytes; and 3)
oligomerization of mPS enhances its avidity for
leukocytes.},
Key = {fds113153}
}
@article{fds113118,
Author = {R Chandra and ED Salmon and HP Erickson and A Lockhart and SA
Endow},
Title = {Structural and functional domains of the Drosophila ncd
microtubule motor protein.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {268},
Number = {12},
Pages = {9005-13},
Year = {1993},
Month = {April},
ISSN = {0021-9258},
Keywords = {Adenosine Triphosphatases • Amino Acid Sequence •
Animals • Base Sequence • DNA • Drosophila
• Drosophila Proteins* • Kinesin* •
Microtubule Proteins • Microtubules • Molecular
Sequence Data • Recombinant Proteins • chemistry
• genetics • isolation & purification •
metabolism • metabolism* • ultrastructure},
Abstract = {Nonclaret disjunctional (ncd) is a kinesin-related
microtubule motor protein that is required for proper
chromosome distribution in Drosophila. Despite its sequence
similarity to kinesin heavy chain, ncd translocates with the
opposite polarity as kinesin, toward microtubule minus ends.
We have expressed different regions of the protein in
bacteria and analyzed the proteins for function. Results
indicate that ncd consists of three domains: a basic,
proline-rich N-terminal "tail," a central alpha-helical
coiled-coil stalk, and a C-terminal motor domain. The ncd N
terminus proteins bundle microtubules in motility assays and
show ATP-independent binding to microtubules in solution.
Truncated proteins, lacking the tail but containing the
predicted motor domain and differing lengths of the stalk,
did not support microtubule gliding in in vitro assays but
showed microtubule-stimulated MgATPase activity in solution.
Addition of a nonspecific N terminus to two of the truncated
proteins restored directional gliding and rotation of
microtubules in motility assays, demonstrating that these
properties map to the predicted mechanochemical domain of
ncd. Physical properties of the C terminus proteins indicate
that the stalk region is important for dimerization and that
the ncd protein probably exists and functions as a
dimer.},
Key = {fds113118}
}
@article{fds113094,
Author = {HP Erickson},
Title = {Gene knockouts of c-src, transforming growth factor beta 1,
and tenascin suggest superfluous, nonfunctional expression
of proteins.},
Journal = {The Journal of cell biology},
Volume = {120},
Number = {5},
Pages = {1079-81},
Year = {1993},
Month = {March},
ISSN = {0021-9525},
Keywords = {Animals • Cell Adhesion Molecules, Neuronal •
Epidermal Growth Factor • Extracellular Matrix Proteins
• Gene Expression Regulation • Genes, src •
Mice • Mutagenesis, Insertional • Nerve Growth
Factors • Proto-Oncogene Proteins pp60(c-src) •
Tenascin • Transforming Growth Factor beta •
physiology • physiology*},
Language = {eng},
Key = {fds113094}
}
@article{fds113205,
Author = {I Aukhil and P Joshi and Y Yan and HP Erickson},
Title = {Cell- and heparin-binding domains of the hexabrachion arm
identified by tenascin expression proteins.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {268},
Number = {4},
Pages = {2542-53},
Year = {1993},
Month = {February},
ISSN = {0021-9258},
Keywords = {Animals • Base Sequence • Binding Sites •
Cell Adhesion • Cell Adhesion Molecules, Neuronal
• Cells, Cultured • Cricetinae • Escherichia
coli • Extracellular Matrix Proteins • Fibroblasts
• Fibronectins • Heparin • Ligands •
Microscopy, Electron • Molecular Sequence Data •
Molecular Weight • Peptide Fragments •
Proteoglycans • Recombinant Proteins •
Structure-Activity Relationship • Sulfates •
Tenascin • chemistry • metabolism •
metabolism* • ultrastructure},
Abstract = {We have produced a set of bacterial expression proteins
corresponding to 10 segments of tenascin and two of
fibronectin and tested them for heparin binding and cell
adhesion. We used polymerase chain reaction cloning to
terminate the segments precisely at domain boundaries.
Heparin binding activity was mapped to two different
tenascin segments: one comprising the fourth and fifth
fibronectin type III domains, and to TNfbg, the
fibrinogen-like terminal knob. TNfbg, but none of the other
tanascin segments, also supported adhesion of primary rat
embryo skin fibroblasts. The fibroblasts did not spread on
TNfbg but remained rounded. Cell binding to TNfbg occurred
in the presence or absence of divalent cations and was not
inhibited by RGD peptides, suggesting that integrins are not
involved. Fibroblast binding to TNfbg was strongly inhibited
by soluble heparin, by treating the cells with heparitinase,
or by culture conditions that cause undersulfation of
proteoglycans. These observations suggest that cell
attachment to TNfbg is mediated by cell surface
proteoglycans. We have also made full-length cDNA constructs
for the largest and smallest splice variants of human
tenascin, as well as one truncated after the 14th epidermal
growth factor-like domain, in the pNUT mammalian cell
expression vector. Stably transfected baby hamster kidney
cell lines secreted large quantities of tenascin, and this
was assembled into normal hexabrachions, the arm length
corresponding to the construct.},
Key = {fds113205}
}
@article{fds113108,
Author = {G Vollmer and VA Lightner and CA Carter and GP Siegal and HP Erickson and R
Knuppen, DG Kaufman},
Title = {Localization of tenascin in uterine sarcomas and partially
transformed endometrial stromal cells.},
Journal = {Pathobiology : journal of immunopathology, molecular and
cellular biology, SWITZERLAND},
Volume = {61},
Number = {2},
Pages = {67-76},
Year = {1993},
ISSN = {1015-2008},
Keywords = {Adult • Cell Adhesion Molecules, Neuronal • Cell
Transformation, Neoplastic* • Cells, Cultured •
Endometrium • Extracellular Matrix Proteins •
Female • Humans • Molecular Weight • Nerve
Tissue Proteins • Oncogenes • Sarcoma •
Tenascin • Transfection • Tumor Cells, Cultured
• Uterine Neoplasms • analysis* •
biosynthesis • metabolism* • pathology*},
Abstract = {Normal mesenchymal cells within developing embryonic organs
and transformed stromal cells in organs undergoing
spontaneous carcinogenesis have the capacity for normal or
altered expression of the extracellular matrix glycoprotein
tenascin (Tn). Mesenchymal cell constituents of normal adult
organs show only a very limited tendency to deposit Tn in
their extracellular matrix. In the present study, we
investigated whether malignant human mesenchymal cells
derived from uterine sarcomas or normal human endometrial
stromal cells partially transformed via transfection with
selected oncogenes have the capacity to produce and deposit
Tn. We reached the following conclusions: (1) compared with
normal endometrial tissues, uterine sarcomas show
heterogeneous, but increased, immunoreactive staining
patterns exclusively within the extracellular compartment,
regardless of the histologic subtype of the tumor; (2) in
vitro, all normal and transfected stromal cells and cell
lines examined secreted Tn into the tissue culture medium;
(3) this secretory ability was not translated into
morphologic uniformity, since immunoreactivity detected by
confocal laser scanning microscopy was observed in only
selected cell populations; (4) also, the deposition and the
incorporation of Tn depended upon the density of transfected
cells, and (5) double-staining experiments revealed that Tn
could always be localized in close proximity to fibronectin.
In summary, the production of Tn is increased in most cases
of human uterine sarcoma. The capacity of stromal cells to
deposit Tn in a matrix-like structure in vitro, rather than
increase production of Tn, is correlated with the degree of
neoplastic progression.},
Key = {fds113108}
}
@article{fds113089,
Author = {DJ Leahy and WA Hendrickson and I Aukhil and HP Erickson},
Title = {Structure of a fibronectin type III domain from tenascin
phased by MAD analysis of the selenomethionyl
protein.},
Journal = {Science (New York, N.Y.)},
Volume = {258},
Number = {5084},
Pages = {987-91},
Year = {1992},
Month = {November},
ISSN = {0036-8075},
Keywords = {Amino Acid Sequence • Animals • Cell Adhesion
Molecules, Neuronal • Chickens • Crystallization
• Escherichia coli • Extracellular Matrix Proteins
• Fibronectins • Humans • Immunoglobulin
Constant Regions • Magnetic Resonance Spectroscopy
• Models, Molecular • Molecular Sequence Data
• Molecular Structure • Protein Folding •
Protein Structure, Secondary • Receptors, Somatotropin
• Recombinant Proteins • Tenascin • X-Ray
Diffraction* • chemistry • chemistry* •
genetics},
Abstract = {Fibronectin type III domains are found in many different
proteins including cell surface receptors and cell adhesion
molecules. The crystal structure of one such domain from the
extracellular matrix protein tenascin was determined. The
structure was solved by multiwavelength anomalous
diffraction (MAD) phasing of the selenomethionyl protein and
has been refined to 1.8 angstrom resolution. The folding
topology of this domain is identical to that of the
extracellular domains of the human growth hormone receptor,
the second domain of CD4, and PapD. Although distinct, this
topology is similar to that of immunoglobulin constant
domains. An Arg-Gly-Asp (RGD) sequence that can function for
cell adhesion is found in a tight turn on an exposed
loop.},
Language = {eng},
Key = {fds113089}
}
@article{fds113190,
Author = {EM Schaefer and HP Erickson and M Federwisch and A Wollmer and L
Ellis},
Title = {Structural organization of the human insulin receptor
ectodomain.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {267},
Number = {32},
Pages = {23393-402},
Year = {1992},
Month = {November},
ISSN = {0021-9258},
Keywords = {Amino Acid Sequence • Animals • Binding Sites
• CHO Cells • Cell Adhesion Molecules, Neuronal
• Circular Dichroism • Cricetinae •
Extracellular Matrix Proteins • Growth Hormone •
Humans • Mathematics • Microscopy, Electron •
Models, Structural • Models, Theoretical •
Molecular Sequence Data • Protein Conformation •
Receptor, Insulin • Recombinant Proteins •
Repetitive Sequences, Nucleic Acid • Sequence Homology,
Amino Acid • Spectrometry, Fluorescence • Tenascin
• Transfection • chemistry • chemistry*
• isolation & purification • ultrastructure},
Abstract = {To provide an experimental system amenable to a detailed
biochemical and structural investigation of the
extracellular (ligand binding) domain of the insulin
receptor, we developed a mammalian heterologous cell
expression system from which tens of milligrams of the
soluble secreted ectodomain (the IR921 protein) can be
routinely purified using methods that do not require harsh
elution conditions. The purified IR921 protein has a Stokes
radius of 6.8 nm and a sedimentation coefficient of 9.8 S,
from which we calculate a hydro-dynamic mass of 281 kDa.
Electron microscopic images, using both rotary shadowing and
negative staining techniques, demonstrate a characteristic
substructure for the IR921 protein consisting of two
elongated arms, with a globular domain at each end,
connected to each other at a point somewhat off-center to
form a Y structure. Analysis using circular dichroism and
fluorescence spectroscopy illustrate that insulin binding
results in conformational changes in the ectodomain.
Furthermore, fluorescence anisotropy decay data reveal
segmental mobility within the IR921 protein that is
successively frozen as a result of insulin binding, in
contrast to results obtained in a previous study of the
epidermal growth factor receptor ectodomain. This result
suggests a divergence in hormone-induced signaling
mechanisms used by the insulin and epidermal growth factor
receptors.},
Key = {fds113190}
}
@article{fds113161,
Author = {SH Northrup and HP Erickson},
Title = {Kinetics of protein-protein association explained by
Brownian dynamics computer simulation.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America},
Volume = {89},
Number = {8},
Pages = {3338-42},
Year = {1992},
Month = {April},
ISSN = {0027-8424},
Keywords = {Computer Simulation* • Kinetics • Mathematics
• Protein Binding • Protein Conformation •
Proteins • chemistry* • metabolism},
Abstract = {Protein-protein bond formations, such as antibody-antigen
complexation or aggregation of protein monomers into dimers
and larger aggregates, occur with bimolecular rate constants
on the order of 10(6) M-1.s-1, which is only 3 orders of
magnitude slower than the diffusion-limited Smoluchowski
rate. However, since the protein-protein bond requires
rotational alignment to within a few angstroms of tolerance,
purely geometric estimates would suggest that the observed
rates might be 6 orders of magnitude below the Smoluchowski
rate. Previous theoretical treatments have not been solved
for the highly specific docking criteria of protein-protein
association--the entire subunit interface must be aligned
within 2 A of the correct position. Several studies have
suggested that diffusion alone could not produce the rapid
association kinetics and have postulated "lengthy
collisions" and/or the operation of electrostatic or
hydrophobic steering forces to accelerate the association.
In the present study, the Brownian dynamics simulation
method is used to compute the rate of association of neutral
spherical model proteins with the stated docking criteria.
The Brownian simulation predicts a rate of 2 x 10(6) M-1.s-1
for this generic protein-protein association, a rate that is
2000 times faster than that predicted by the simplest
geometric calculation and is essentially equal to the rates
observed for protein-protein association in aqueous
solution. This high rate is obtained by simple diffusive
processes and does not require any attractive or steering
forces beyond those achieved for a partially formed bond.
The rate enhancement is attributed to a diffusive entrapment
effect, in which a protein pair surrounded and trapped by
water undergoes multiple collisions with rotational
reorientation during each encounter.},
Language = {eng},
Key = {fds113161}
}
@article{fds113208,
Author = {EK LeMosy and HP Erickson and WF Beyer and JT Radek and JM Jeong and SN
Murthy, L Lorand},
Title = {Visualization of purified fibronectin-transglutaminase
complexes.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {267},
Number = {11},
Pages = {7880-5},
Year = {1992},
Month = {April},
ISSN = {0021-9258},
Keywords = {Animals • Cross-Linking Reagents •
Electrophoresis, Polyacrylamide Gel • Erythrocytes
• Fibronectins • Fluorescence Polarization •
Guinea Pigs • Humans • Liver • Microscopy,
Electron • Silver Staining • Species Specificity
• Transglutaminases • Tumor Cells, Cultured •
enzymology • isolation & purification •
metabolism* • ultrastructure},
Abstract = {It has been reported previously (Turner, P.M., and Lorand,
L. (1989) Biochemistry 28, 628-635) that human erythrocyte
transglutaminase forms a noncovalent complex with human
plasma fibronectin near its collagen-binding domain. In the
present study, we show by nondenaturing electrophoresis that
guinea pig liver transglutaminase, similarly to the
erythrocyte enzyme, forms a complex with human fibronectin.
Studies of anisotropic shifts of fluorescein-labeled liver
and erythrocyte transglutaminases, upon addition of
fibronectin, indicated that both transglutaminases bind to
fibronectin with a stoichiometry of about 2:1.
Polymerization of fibrinogen by human erythrocyte
transglutaminase was inhibited after complex formation with
fibronectin. Complexes of fibronectin with either
erythrocyte or liver transglutaminase were isolated by
glycerol gradient zone sedimentation and examined by rotary
shadowing electron microscopy. The globular transglutaminase
could be readily identified binding to the thin fibronectin
strand. The binding site for transglutaminase was within
5-10 nm of the N terminus of fibronectin, consistent with
its proximity to the collagen-binding domain. Under some
experimental conditions, the complex of fibronectin with
erythrocyte transglutaminase appeared as a ring-shaped
structure in which two transglutaminase molecules had
probably dimerized. The molecular weight of the erythrocyte
transglutaminase was determined by sedimentation equilibrium
to be 71,440 +/- 830.},
Key = {fds113208}
}
@article{fds113169,
Author = {HP Erickson and ET O'Brien},
Title = {Microtubule dynamic instability and GTP hydrolysis.},
Journal = {Annual review of biophysics and biomolecular structure,
UNITED STATES},
Volume = {21},
Pages = {145-66},
Year = {1992},
ISSN = {1056-8700},
Keywords = {Animals • GTP-Binding Proteins • Guanosine
Diphosphate • Guanosine Triphosphate • Hydrolysis
• Kinetics • Microtubules • Tubulin •
chemistry • metabolism • metabolism* •
ultrastructure*},
Key = {fds113169}
}
@article{fds113082,
Author = {JE Murphy-Ullrich and VA Lightner and I Aukhil and YZ Yan and HP
Erickson, M Höök},
Title = {Focal adhesion integrity is downregulated by the
alternatively spliced domain of human tenascin.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {115},
Number = {4},
Pages = {1127-36},
Year = {1991},
Month = {November},
ISSN = {0021-9525},
Keywords = {Actins • Animals • Antibodies • Aorta •
Cattle • Cell Adhesion • Cell Adhesion Molecules,
Neuronal • Cell Line • Chondroitin Sulfates •
Cloning, Molecular • Down-Regulation •
Endothelium, Vascular • Extracellular Matrix •
Extracellular Matrix Proteins • Glycosaminoglycans
• Peptide Fragments • RNA Splicing* •
Tenascin • Vinculin • cytology • cytology*
• genetics • immunology • metabolism •
metabolism*},
Abstract = {Tenascin, together with thrombospondin and SPARC, form a
family of matrix proteins that, when added to bovine aortic
endothelial cells, caused a dose-dependent reduction in the
number of focal adhesion-positive cells to approximately 50%
of albumin-treated controls. For tenascin, a maximum
response was obtained with 20-60 micrograms/ml of protein.
The reduction in focal adhesions in tenascin-treated spread
cells was observed 10 min after addition of the adhesion
modulator, reached the maximum by 45 min, and persisted for
at least 4 h in the continued presence of tenascin. This
effect was fully reversible, was independent of de novo
protein synthesis, and was neutralized by a polyclonal
antibody to tenascin. Monoclonal antibodies to specific
domains of tenascin (mAbs 81C6 and 127) were used to
localize the active site to the alternatively spliced
segment of tenascin. Furthermore, a recombinant protein
corresponding to the alternatively spliced segment
(fibronectin type III domains 6-12) was expressed in
Escherichia coli and was active in causing loss of focal
adhesions, whereas a recombinant form of a domain (domain 3)
containing the RGD sequence had no activity.
Chondroitin-6-sulfate effectively neutralized tenascin
activity, whereas dermatan sulfate and chondroitin-4-sulfate
were less active and heparan sulfate and heparin were
essentially inactive. Studies suggest that
galactosaminoglycans neutralize tenascin activity through
interactions with cell surface molecules. Overall, our
results demonstrate that tenascin, thrombospondin, and
SPARC, acting as soluble ligands, are able to provoke the
loss of focal adhesions in well-spread endothelial
cells.},
Key = {fds113082}
}
@article{fds113112,
Author = {WA Voter and ET O'Brien and HP Erickson},
Title = {Dilution-induced disassembly of microtubules: relation to
dynamic instability and the GTP cap.},
Journal = {Cell motility and the cytoskeleton, UNITED
STATES},
Volume = {18},
Number = {1},
Pages = {55-62},
Year = {1991},
ISSN = {0886-1544},
Keywords = {Animals • Guanosine Triphosphate • Kinetics •
Microtubules • Solutions • Tubulin •
metabolism • metabolism* • physiology*},
Abstract = {Microtubules were assembled from purified tubulin in the
buffer originally used to study dynamic instability (100 mM
PIPES, 2 mM EGTA, 1 mM magnesium, 0.2 mM GTP) and then
diluted in the same buffer to study the rate of disassembly.
Following a 15-fold dilution, microtubule polymer decreased
linearly to about 20% of the starting value in 15 sec. We
determined the length distribution of microtubules before
dilution, and prepared computer simulations of polymer loss
for different assumed rates of disassembly. Our experimental
data were consistent with a disassembly rate per microtubule
of 60 microns/min. This is the total rate of
depolymerization for microtubules in the rapid shortening
phase, as determined by light microscopy of individual
microtubules (Walker et al.: Journal of Cell Biology
107:1437-1448, 1988). We conclude, therefore, that
microtubules began rapid shortening at both ends upon
dilution. Moreover, since we could detect no lag between
dilution and the onset of rapid disassembly, the transition
from elongation to rapid shortening apparently occurred
within 1 sec following dilution. Assuming that this
transition (catastrophe) involves the loss of the GTP cap,
and that cap loss is achieved by the sequential dissociation
of GTP-tubulin subunits following dilution, we can estimate
the maximum size of the cap based on the kinetic data and
model interpretation of Walker et al. The cap is probably
shorter than 40 and 20 subunits at the plus and minus ends,
respectively.},
Key = {fds113112}
}
@article{fds113107,
Author = {ET O'Brien and ED Salmon and RA Walker and HP Erickson},
Title = {Effects of magnesium on the dynamic instability of
individual microtubules.},
Journal = {Biochemistry, UNITED STATES},
Volume = {29},
Number = {28},
Pages = {6648-56},
Year = {1990},
Month = {July},
ISSN = {0006-2960},
Keywords = {Animals • Brain Chemistry • Guanosine Triphosphate
• Magnesium • Microtubules • Swine •
Tubulin • Videotape Recording • drug effects*
• metabolism • metabolism* •
pharmacology*},
Abstract = {We investigated the effect of magnesium ion (Mg) on the
parameters of dynamic instability of individual porcine
brain microtubules. Rates of elongation and rapid shortening
were measured by using video-enhanced DIC light microscopy
and evaluated by using computer-generated plots of
microtubule length vs time. Increasing [Mg] from 0.25 to 6
mM increased the second-order association rate constant for
elongation about 25% at each end. At plus ends, this
resulted in a 1.5-2-fold increase in elongation rates over
the tubulin concentrations explored. Rapid shortening rates
were more dramatically affected by Mg. As [Mg] was increased
from 0.25 to 6 mM, the average rate of rapid shortening
increased about 3-fold at plus ends and 4-5-fold at minus
ends. The ends had roughly equivalent average rates at low
[Mg], of 30-45 microns/min. At any Mg concentration, rates
of disassembly varied from one microtubule to another, and
often an individual microtubule would exhibit more than one
rate during a single shortening phase. Individual rates at 6
mM Mg varied from 12 to 250 microns/min. Over the
concentration range explored, Mg affected the frequencies of
transition from elongation to shortening and back only at
minus ends. Minus ends were relatively stable at low [Mg],
having 4 times the frequency of rescue than at high [Mg],
and a lower frequency of catastrophe (particularly evident
at low tubulin concentrations). Plus ends, surprisingly,
were highly unstable at all Mg concentrations investigated,
having about the same transition frequencies as did the
least stable (high Mg) minus ends. Our results have
implications for models of the GTP cap, again emphasizing
that GTP caps cannot build up in proportion to elongation
rate, and must be constrained to the tips of growing
microtubules.},
Key = {fds113107}
}
@article{fds113122,
Author = {I Aukhil and CC Slemp and VA Lightner and K Nishimura and G Briscoe and HP
Erickson},
Title = {Purification of hexabrachion (tenascin) from cell culture
conditioned medium, and separation from a cell adhesion
factor.},
Journal = {Matrix (Stuttgart, Germany), GERMANY, WEST},
Volume = {10},
Number = {2},
Pages = {98-111},
Year = {1990},
Month = {May},
ISSN = {0934-8832},
Keywords = {Astrocytes • Cell Adhesion Molecules • Cell
Adhesion Molecules, Neuronal • Chromatography, Gel
• Culture Media • Glioma • Humans •
Tenascin • analysis* • isolation & purification*
• metabolism* • methods*},
Abstract = {We describe a protocol for purifying hexabrachion from
conditioned medium of cell cultures, using gel filtration
chromatography on Sephacryl 500, followed by anion-exchange
chromatography on a Mono Q column, followed optionally by a
second gel filtration or zone sedimentation on glycerol
gradients. The protocol has several advantages over previous
procedures based on affinity chromatography on monoclonal
antibodies. Perhaps foremost, the protein is never exposed
to the denaturing solvents that are required for elution
from the antibody column. The Mono Q column also separated
hexabrachion from a prominent cell adhesion activity that
eluted with the hexabrachion on the first gel filtration,
and co-sedimented with hexabrachions on glycerol gradients.
The cell adhesion fractions showed several bands between 190
and 400 kDa. A single band at 220 kDa stained prominently
with a polyclonal antibody against mouse EHS laminin, and a
band at 190 kDa stained with a monoclonal antibody against
s-laminin. The purification protocol gave hexabrachion at
high concentration and with no detectable contamination by
fibronectin or laminin. The highest yield of hexabrachion
(1-4 mg from 400 ml of conditioned medium) was from human
glioblastoma cell cultures, but the same procedure allowed
us to purify and characterize the rat hexabrachion. Protein
purified from primary cultures of rat embryo fibroblasts
showed approximately equal amounts of three subunit sizes:
280, 230, and 220 kDa. These different subunits, presumably
derived from alternative RNA splicing, appeared to be
segregated into large and small hexabrachions, which could
be separated on glycerol gradients.},
Key = {fds113122}
}
@article{fds113159,
Author = {MD Neely and HP Erickson and K Boekelheide},
Title = {HMW-2, the Sertoli cell cytoplasmic dynein from rat testis,
is a dimer composed of nearly identical subunits.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {265},
Number = {15},
Pages = {8691-8},
Year = {1990},
Month = {May},
ISSN = {0021-9258},
Keywords = {Adenosine Triphosphatases • Animals • Cytoplasm
• Dynein ATPase • Macromolecular Substances •
Male • Microscopy, Electron • Molecular Weight
• Rats • Sertoli Cells • enzymology •
enzymology* • isolation & purification* •
ultrastructure},
Abstract = {The ultrastructure and biochemical characteristics of HMW-2,
the Sertoli cell cytoplasmic dynein isolated from rat
testes, were analyzed. Electron microscopic studies revealed
a two-headed two-stem structure with dimensions very similar
to other dyneins. We found that, like other cytoplasmic
dyneins, both heads have an approximately spherical shape
with a central cavity. Heavy chain analysis suggested the
presence of only one type of heavy chain, a finding that was
supported by the simple Michaelis-Menten kinetics displayed
by the HMW-2-associated ATPase activity. In addition,
dissociation of the HMW-2 complex resulted in a single type
of dynein subunit sedimenting at 11.8 S. This fraction
contained all the polypeptides present in the undissociated
HMW-2. Ultrastructurally the HMW-2 subunits were composed of
one globular domain with a tail. The simplest interpretation
is that HMW-2 is a dimer of nearly identical subunits, each
containing one heavy chain, one 90-kDa intermediate chain,
and two light chains.},
Key = {fds113159}
}
@article{fds113187,
Author = {DE Staunton and ML Dustin and HP Erickson and TA Springer},
Title = {The arrangement of the immunoglobulin-like domains of ICAM-1
and the binding sites for LFA-1 and rhinovirus.},
Journal = {Cell, UNITED STATES},
Volume = {61},
Number = {2},
Pages = {243-54},
Year = {1990},
Month = {April},
ISSN = {0092-8674},
Keywords = {Amino Acid Sequence • Animals • Antigens, CD
• Antigens, Differentiation • Cell Adhesion
Molecules • Cell Line • Chimera • Chromosome
Deletion • Humans • Immunoglobulins •
Intercellular Adhesion Molecule-1 • Kinetics •
Lymphocyte Function-Associated Antigen-1 • Membrane
Glycoproteins • Mice • Models, Molecular •
Molecular Sequence Data • Mutation •
Oligonucleotide Probes • Protein Binding • Protein
Conformation • Receptors, Leukocyte-Adhesion •
Receptors, Virus • Rhinovirus • genetics •
genetics* • immunology • immunology* •
metabolism • metabolism* • physiology*},
Abstract = {Intercellular adhesion molecule 1 (ICAM-1, CD54) binds to
the integrin LFA-1 (CD11a/CD18), promoting cell adhesion in
immune and inflammatory reactions. ICAM-1 is also subverted
as a receptor by the major group of rhinoviruses. Electron
micrographs show that ICAM-1 is a bent rod, 18.7 nm long,
suggesting a model in which the five immunoglobulin-like
domains are oriented head to tail at a small angle to the
rod axis. ICAM-1 sequences important to binding LFA-1,
rhinovirus, and four monoclonal antibodies were identified
through the characterization of chimeric ICAM-1 molecules
and mutants. The amino-terminal two immunoglobulin-like
domains of ICAM-1 appear to interact conformationally.
Domain 1 of ICAM-1 contains the primary site of contact for
both LFA-1 and rhinovirus; the presence of domains 3-5
markedly affects the accessibility of the binding site for
rhinovirus and less so for LFA-1. The binding sites appear
to be distinct but overlapping; rhinovirus binding also
differs from LFA-1 binding in its lack of divalent cation
dependence. Our analysis suggests that rhinoviruses mimic
LFA-1 in binding to the most membrane-distal, and thus most
accessible, site of ICAM-1.},
Key = {fds113187}
}
@article{fds113192,
Author = {VA Lightner and HP Erickson},
Title = {Binding of hexabrachion (tenascin) to the extracellular
matrix and substratum and its effect on cell
adhesion.},
Journal = {Journal of cell science, ENGLAND},
Volume = {95 ( Pt 2)},
Pages = {263-77},
Year = {1990},
Month = {February},
ISSN = {0021-9533},
Keywords = {Cell Adhesion • Cell Adhesion Molecules, Neuronal
• Enzyme-Linked Immunosorbent Assay •
Extracellular Matrix • Fibronectins • Humans
• Plastics • Protein Binding • Tenascin
• metabolism • metabolism* • methods •
physiology},
Abstract = {Hexabrachion is a large glycoprotein of the extracellular
matrix (ECM) that is prominent in embryogenesis, wound
healing and tumorigenesis. Because of the role of
extracellular matrix proteins in the regulation of cell
differentiation and migration, the interaction of
hexabrachion with cells as well as with other components of
the ECM is of great interest. Early reports suggested that
hexabrachion does not bind to fibronectin or gelatin but
does bind to chondroitin sulfate proteoglycans. However,
more recent reports have suggested that hexabrachion binds
to fibronectin and inhibits cell adhesion as well as cell
migration on fibronectin. We have found no evidence of
strong hexabrachion-fibronectin binding on either a
solid-phase ELISA assay or in a fluid-phase sedimentation
assay in which the reactants were allowed to dissociate.
However, hexabrachion sedimentation was accelerated in a
gradient containing fibronectin throughout. This
demonstrates an association between hexabrachions and
fibronectin, but the complex is apparently weak and readily
reversible. The solid-phase ELISA also shows no evidence of
hexabrachion binding to gelatin, laminin or types I, III, IV
or V collagen. Hexabrachion does not support strong cell
attachment of the cell lines tested. Moreover, hexabrachion
can inhibit cell attachment to fibronectin. We demonstrate
here that this inhibition requires the hexabrachion to be
able to bind to the plastic substratum. The results suggest
that hexabrachion inhibition is via a steric inhibition.
When the hexabrachion molecules bind to the plastic, they
cover up a significant fraction of the underlying
fibronectin molecules. Antibody studies are presented that
show that hexabrachion can nonspecifically block access of
immunoglobulin G molecules to the underlying matrix. This
steric blocking is not unique to hexabrachion.},
Key = {fds113192}
}
@article{fds113111,
Author = {VA Lightner and CA Slemp and HP Erickson},
Title = {Localization and quantitation of hexabrachion (tenascin) in
skin, embryonic brain, tumors, and plasma.},
Journal = {Annals of the New York Academy of Sciences, UNITED
STATES},
Volume = {580},
Pages = {260-75},
Year = {1990},
ISSN = {0077-8923},
Keywords = {Animals • Brain • Cell Adhesion Molecules,
Neuronal • Cells, Cultured • Chick Embryo •
Humans • Immunoenzyme Techniques • Neoplasm
Proteins • Nerve Tissue Proteins • Osteosarcoma
• Skin • Tenascin • analysis • analysis*
• blood • cytology* • embryology •
pathology* • ultrastructure},
Key = {fds113111}
}
@article{fds113119,
Author = {HC Taylor and VA Lightner and WF Beyer and D McCaslin and G Briscoe and HP
Erickson},
Title = {Biochemical and structural studies of tenascin/hexabrachion
proteins.},
Journal = {Journal of cellular biochemistry, UNITED
STATES},
Volume = {41},
Number = {2},
Pages = {71-90},
Year = {1989},
Month = {October},
ISSN = {0730-2312},
Keywords = {Animals • Cell Adhesion Molecules, Neuronal •
Cells, Cultured • Chick Embryo • Circular
Dichroism • Extracellular Matrix* • Fibroblasts
• Glioma • Glycoside Hydrolases • Humans
• Microscopy, Electron • Molecular Weight •
Oxidation-Reduction • Protein Conformation •
Tenascin • Tumor Cells, Cultured • analysis •
isolation & purification • metabolism •
ultrastructure*},
Abstract = {Tenascin is a large, disulfide-bonded glycoprotein of the
extracellular matrix. The predominant form of tenascin
observed by electron microscopy is a six-armed oligomer,
termed a hexabrachion. We have determined the molecular mass
of the native human hexabrachion to be 1.9 x 10(6) Da by
sedimentation equilibrium analysis and by electrophoresis on
non-reducing agarose gels. On reducing polyacrylamide gel
electrophoresis (SDS-PAGE), human tenascin showed a single
prominent band at 320 kDa and minor bands of 220 and 230
kDa. The molecular weight of the native human hexabrachion
is thus consistent with a disulfide-bonded hexamer of the
320 kDa subunits. Upon treatment with neuraminidase, the
apparent molecular weights of all human and chicken tenascin
subunits on reducing SDS-PAGE were decreased by about 10
kDa. Prolonged incubation with alpha-mannosidase, however,
caused no apparent change in the apparent molecular weight
of tenascin subunits. Sedimentation in a cesium chloride
gradient gave a higher buoyant density for human tenascin
than for fibronectin, suggesting that it has a higher degree
of glycosylation. The far-UV circular dichroism spectrum
indicates a predominance of beta-structure and a lack of
collagen-like or alpha-helical structure. When human
hexabrachions were reduced and acetylated, the resulting
fragments were single arms which sedimented at 6 S in
glycerol gradients and migrated at 320 kDa on non-reducing
gels. Treatment of tenascin with trypsin and
alpha-chymotrypsin also produced large fragments which were
fractionated by gradient sedimentation and analyzed by
non-reducing SDS-PAGE and electron microscopy. We present a
structural model for the assembly of the observed fragments
into the elaborate native hexabrachion.},
Key = {fds113119}
}
@article{fds113131,
Author = {MM Lotz and CA Burdsal and HP Erickson and DR McClay},
Title = {Cell adhesion to fibronectin and tenascin: quantitative
measurements of initial binding and subsequent strengthening
response.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {109},
Number = {4 Pt 1},
Pages = {1795-805},
Year = {1989},
Month = {October},
ISSN = {0021-9525},
Keywords = {Animals • Astrocytoma • Cell Adhesion Molecules,
Neuronal • Cell Adhesion* • Cell Line •
Cytochalasin B • Fibroblasts • Fibronectins •
Glioma • Humans • Kinetics • Neoplasm
Proteins • Tenascin • cytology • drug effects
• pharmacology • physiology*},
Abstract = {Cell-substratum adhesion strengths have been quantified
using fibroblasts and glioma cells binding to two
extracellular matrix proteins, fibronectin and tenascin. A
centrifugal force-based adhesion assay was used for the
adhesive strength measurements, and the corresponding
morphology of the adhesions was visualized by interference
reflection microscopy. The initial adhesions as measured at
4 degrees C were on the order of 10(-5)dynes/cell and did
not involve the cytoskeleton. Adhesion to fibronectin after
15 min at 37 degrees C were more than an order of magnitude
stronger; the strengthening response required cytoskeletal
involvement. By contrast to the marked strengthening of
adhesion to FN, adhesion to TN was unchanged or weakened
after 15 min at 37 degrees C. The absolute strength of
adhesion achieved varied according to protein and cell type.
When a mixed substratum of fibronectin and tenascin was
tested, the presence of tenascin was found to reduce the
level of the strengthening of cell adhesion normally
observed at 37 degrees C on a substratum of fibronectin
alone. Parallel analysis of corresponding interference
reflection micrographs showed that differences in the area
of cell surface within 10-15 nm of the substratum correlated
closely with each of the changes in adhesion observed: after
incubation for 15 min on fibronectin at 37 degrees C, glioma
cells increased their surface area within close contact to
the substrate by integral to 125-fold. Cells on tenascin did
not increase their surface area of contact. The increased
surface area of contact and the inhibitory activity of
cytochalasin b suggest that the adhesive "strengthening" in
the 15 min after initial binding brings additional adhesion
molecules into the adhesive site and couples the actin
cytoskeleton to the adhesion complex.},
Key = {fds113131}
}
@article{fds113127,
Author = {VA Lightner and F Gumkowski and DD Bigner and HP Erickson},
Title = {Tenascin/hexabrachion in human skin: biochemical
identification and localization by light and electron
microscopy.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {108},
Number = {6},
Pages = {2483-93},
Year = {1989},
Month = {June},
ISSN = {0021-9525},
Keywords = {Antibodies, Monoclonal • Blotting, Western •
Epidermis • Extracellular Matrix • Fluorescent
Antibody Technique • Glycoproteins • Humans •
Immunoenzyme Techniques • Molecular Weight •
Proteins • Skin • Tenascin • analysis •
analysis* • immunology • ultrastructure},
Abstract = {Tenascin/hexabrachion is a large glycoprotein of the
extracellular matrix. Previous reports have demonstrated
that tenascin is associated with epithelial-mesenchymal
interfaces during embryogenesis and is prominent in the
matrix of many tumors. However, the distribution of tenascin
is more restricted in adult tissues. We have found tenascin
to be present in normal human skin in a distribution
distinct from other matrix proteins. Immunohistochemical
studies showed staining of the papillary dermis immediately
beneath the basal lamina. Examination of skin that had been
split within the lamina lucida of the basement membrane
suggested a localization of tenascin beneath the lamina
lucida. In addition, there was finely localized staining
within the walls of blood vessels and in the smooth muscle
bundles of the arrectori pilorem. Very prominent staining
was seen around the cuboidal cells that formed the basal
layer of sweat gland ducts. The sweat glands themselves did
not stain. The distribution of tenascin in the papillary
dermis was studied at high resolution by immunoelectron
microscopy. Staining was concentrated in small amorphous
patches scattered amongst the collagen fibers beneath the
basal lamina. These patches were not associated with cell
structures, collagen, or elastic fibers. Tenascin could be
partially extracted from the papillary dermis by urea,
guanidine hydrochloride, or high pH solution. The extracted
protein showed a 320-kD subunit similar to that purified
from fibroblast or glioma cell cultures. We have developed a
sensitive ELISA assay that can quantitate tenascin at
concentrations as low as 5 ng/ml. Tests on extracts of the
papillary dermis showed tenascin constituted about
0.02-0.05% of the protein extracted.},
Key = {fds113127}
}
@article{fds113121,
Author = {EJ O'Keefe and HP Erickson and V Bennett},
Title = {Desmoplakin I and desmoplakin II. Purification and
characterization.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {264},
Number = {14},
Pages = {8310-8},
Year = {1989},
Month = {May},
ISSN = {0021-9258},
Keywords = {Animals • Chemistry, Physical • Chromatography,
DEAE-Cellulose • Cross-Linking Reagents •
Cytoskeletal Proteins* • Desmoplakins • Desmosomes
• Electrophoresis, Polyacrylamide Gel • Epithelium
• Keratins • Macromolecular Substances •
Membrane Glycoproteins • Microscopy, Electron •
Molecular Weight • Protein Precursors •
Succinimides • Swine • Tongue • Urea •
analysis • analysis* • isolation & purification*
• metabolism},
Abstract = {Desmoplakins I and II (DP1 and DP2), major cytoskeletal
structural proteins concentrated in desmosomes, have been
purified in milligram quantities from keratomed pig tongue
epithelium. DP1 and DP2 extracted from purified desmosomes
in 4 M urea were chromatographed on DEAE-cellulose and
remained soluble after removal of urea during subsequent
chromatography. The two proteins differed by only about 15%
in molecular weight (Mr = 285,000 for DP1 and 225,000 for
DP2 on sodium dodecyl sulfate-polyacrylamide gels) were
found to have similar Svedberg constants, 6.7 S (DP1) and
6.4 S (DP2); nevertheless, separation was readily achieved
by gel filtration, since DP1 has a Stokes radius (Rs) of 164
nm, but DP2 has a Rs = 90 nm. Calculated molecular mass was
462,000 daltons for DP1 and 242,000 daltons for DP2,
suggesting that DP1 may be a dimer in solution and DP2 a
monomer. Cross-linking by disuccinimidyl suberate of
125I-labeled DP1 or DP2 at nanomolar concentrations
confirmed that DP1 is a dimer by doubling of its apparent Mr
on sodium dodecyl sulfate gels and indicated that DP2, which
failed to become cross-linked, is a monomer. DP1 in the
presence of 8 M urea could not be cross-linked, indicating
that urea dissociated the dimers. Calculated frictional
ratios (f/f0 = 3 for DP1 and 2 for DP2) indicate that both
proteins are highly asymmetric. Rotary shadowing of DP1
demonstrated flexible dumbbell-like extended shapes with a
maximal length of about 180 nm with a central rod and coiled
or folded end domains. DP2 showed variable extended shapes
of maximal length of 78-93 nm. The increased length and Rs
of desmoplakin I is probably accounted for by formation of
tail-to-tail dimers. Two-dimensional peptide maps and amino
acid analysis showed very similar profiles for the two
proteins. Purified keratin filaments failed to bind DP1 or
DP2, and prekeratins polymerized in vitro and sedimented
failed to remove desmoplakins, suggesting that desmoplakins
do not bind keratins directly. These studies provide a basis
for functional and detailed structural studies with purified
native desmosomal proteins.},
Key = {fds113121}
}
@article{fds113136,
Author = {HP Erickson},
Title = {Co-operativity in protein-protein association. The structure
and stability of the actin filament.},
Journal = {Journal of molecular biology},
Volume = {206},
Number = {3},
Pages = {465-74},
Year = {1989},
Month = {April},
ISSN = {0022-2836},
Keywords = {Actins • Animals • Antibodies • Energy
Metabolism • Kinetics • Macromolecular Substances
• Models, Chemical • Molecular Structure •
Protein Conformation • Thermodynamics • metabolism
• metabolism*},
Abstract = {Co-operative association, in which a protein subunit is held
simultaneously by two bonds, is enormously more favorable
than association forming either bond alone. A theoretical
framework for calculating the effect of co-operativity is
developed here, which should have a broad application to
protein-protein and protein-DNA associations. The theory is
applied in detail to actin. Fragmentation of an actin
filament is extremely unfavorable: the association constant
for annealing-fragmentation is estimated here to be at least
10(13) M-1. In contrast to these very strong bonds within
the filament, subunits are loosely attached at the end, with
an association constant of 2 x 10(5) M-1. The eight orders
of magnitude difference between annealing-fragmentation and
end association can be attributed to the co-operative
formation of one additional protein-protein bond in the
annealing reaction. This observation, and a quantitative
analysis of the co-operativity, lead to an important
conclusion: the longitudinal bond, which connects subunits
in the long-pitch helix, must be substantially stronger than
the diagonal bond, which connect subunits between these
helices. This conclusion contradicts some recent models
based on Fourier construction, in which the longitudinal
bond is weak or absent. Prominent longitudinal bonds also
require a rigidity of the actin filament that must be
reconciled with previous reports of torsional flexibility. A
hinge within the actin subunit is suggested, separating it
into two flexibly attached domains. In one possible model
the two domains are oriented radially: the inner domains are
connected by longitudinal and diagonal bonds to form a
relatively rigid helical backbone, and the outer domains are
attached to this backbone by flexible hinges, permitting
them to move through angles of 10 degrees to 20 degrees or
more. Flexibility of the outer, myosin-binding domain should
be functionally important, permitting attachment of myosin
cross-bridges over a range of angles.},
Language = {eng},
Key = {fds113136}
}
@article{fds113144,
Author = {N Kirshner and JJ Corcoran and HP Erickson},
Title = {Synthesis of alpha 2-macroglobulin by bovine adrenal
cortical cell cultures.},
Journal = {The American journal of physiology, UNITED
STATES},
Volume = {256},
Number = {4 Pt 1},
Pages = {C779-85},
Year = {1989},
Month = {April},
ISSN = {0002-9513},
Keywords = {Adrenal Cortex • Adrenal Medulla • Animals •
Cattle • Cells, Cultured • Centrifugation, Density
Gradient • Chromaffin System • Chromatography
• Electrophoresis, Polyacrylamide Gel •
Fluorescent Antibody Technique • Histocytochemistry
• Immunosorbent Techniques • Kinetics •
Microscopy, Electron • alpha-Macroglobulins •
biosynthesis* • metabolism • metabolism*},
Abstract = {Primary cultures of bovine adrenal medullary cells
synthesize and secrete a high-molecular-weight protein into
the culture medium. The protein was purified from the
serum-free medium of cultured cells and was identified as
alpha 2-macroglobulin by gel electrophoresis, sedimentation
velocity, electron microscopy, immunoprecipitation,
immunodiffusion, and autoradiography. Antisera directed
against the protein were prepared and used to determine the
cell types that synthesize the protein. Immunohistofluorescence
studies show that adrenal cortical cells present in the
adrenal medullary cell cultures reacted with the antisera to
the protein purified from the medium, but adrenal medullary
chromaffin cells did not. Cell cultures prepared from bovine
adrenal cortex also synthesize and secrete alpha
2-macroglobulin and react with the antisera.},
Key = {fds113144}
}
@article{fds113212,
Author = {AM Jones and HP Erickson},
Title = {Domain structure of phytochrome from Avena sativa visualized
by electron microscopy.},
Journal = {Photochemistry and photobiology, ENGLAND},
Volume = {49},
Number = {4},
Pages = {479-83},
Year = {1989},
Month = {April},
ISSN = {0031-8655},
Keywords = {Cereals • Microscopy, Electron • Phytochrome
• Plant Proteins • Protein Conformation •
analysis* • ultrastructure},
Abstract = {Highly purified phytochrome from Avena sativa was visualized
by electron microscopy after negative staining with uranyl
acetate and after rotary shadowing with platinum. The
particle shape was variable in both types of specimens, but
tripartite structures resembling a 'Y' were consistently
observed. The tripartite substructure is composed of three
globular domains each having a diameter of 7 to 8 nm and
equally spaced in an equilateral triangle. The dimensions of
the tripartite particle measured 15 nm between the centers
of any two of the three particles. When phytochrome was
digested with trypsin in a manner which releases the
amino-terminal globular domain from the polypeptide, the
tripartite structure was lost and only small globular
particles were seen. We propose that the outer particles of
this tripartite structure are the amino-terminal domains of
the phytochrome dimer, and the central particle comprises
the carboxyl domains of the two subunits.},
Key = {fds113212}
}
@article{fds113138,
Author = {ET O'Brien and HP Erickson},
Title = {Assembly of pure tubulin in the absence of free GTP: effect
of magnesium, glycerol, ATP, and the nonhydrolyzable GTP
analogues.},
Journal = {Biochemistry, UNITED STATES},
Volume = {28},
Number = {3},
Pages = {1413-22},
Year = {1989},
Month = {February},
ISSN = {0006-2960},
Keywords = {Adenosine Triphosphate • Animals • Brain •
Glycerol • Guanosine Triphosphate • Kinetics
• Macromolecular Substances • Magnesium •
Swine • Tubulin • analogs & derivatives* •
metabolism • metabolism* • pharmacology*},
Abstract = {We describe in vitro microtubule assembly that exhibits, in
bulk solution, behavior consistent with the GTP cap model of
dynamic instability. Microtubules assembled from pure
tubulin in the absence of free nucleotides could undergo one
cycle of assembly, but could not sustain an assembly
plateau. After the initial peak of assembly was reached and
bound E-site GTP hydrolyzed to GDP, the microtubules
gradually disassembled. We studied buffer conditions that
maximized this disassembly while still allowing robust
assembly to take place. While both glycerol and glutamate
increased the rate of initial assembly and then slowed
disassembly, magnesium promoted initial assembly and,
surprisingly, enhanced disassembly. After cooling, a second
cycle of assembly was unsuccessful unless GTP or the
hydrolyzable GTP analogue GMPCPOP was readded. The
nonhydrolyzable GTP analogues GMPPNP and GMPPCP could not
support the second assembly cycle in the absence of E-site
GTP. Analysis using HPLC found no evidence that GMPPNP,
GMPPCP, or ATP could bind to free tubulin, and these
nucleotides did not compete with GTP for the E-site. We
have, however, demonstrated that the nonhydrolyzable GTP
analogues and ATP do have an important effect on microtubule
assembly. GMPPNP, GMPPCP, and ATP could each enhance the
rate of assembly and stabilize the plateau of assembled
microtubules against disassembly, while not binding
appreciably to free tubulin. We conclude that these
nucleotides, as well as GTP itself, enhance assembly by
binding to a site on microtubules that is not present on
free, unpolymerized tubulin. We estimate the affinity (KD)
of the polymeric site for nucleotide triphosphates to be
approximately 10(-4)M.},
Key = {fds113138}
}
@article{fds113191,
Author = {JW Becker and HP Erickson and S Hoffman and BA Cunningham and GM
Edelman},
Title = {Topology of cell adhesion molecules.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America, UNITED STATES},
Volume = {86},
Number = {3},
Pages = {1088-92},
Year = {1989},
Month = {February},
ISSN = {0027-8424},
Keywords = {Antibodies • Antigens, Surface* • Cell Adhesion
• Cell Adhesion Molecules • Immunoglobulins •
Membrane Glycoproteins* • Microscopy, Electron •
Models, Molecular • Peptide Fragments • Protein
Conformation • Structure-Activity Relationship},
Abstract = {The neural cell adhesion molecule (N-CAM) exists in two
major forms [ld (large cytoplasmic domain) peptide and sd
(small cytoplasmic domain) peptide] that contain
transmembrane segments and different cytoplasmic domains and
in a third form [ssd (small surface domain) peptide] that
lacks transmembrane and cytoplasmic regions. All forms have
the same extracellular region of more than 600 amino acid
residues, a region also found in a fragment (Fr2) that can
be released from cells by proteolysis. The liver cell
adhesion molecule (L-CAM) is expressed as a single species
that is distinct from N-CAM, but its extracellular region
can also be obtained as a proteolytic fragment (Ft1).
Examination of the various forms of N-CAM and the Ft1
fragment of L-CAM by electron microscopy of rotary shadowed
molecules indicated that they all have rod-shaped structures
that contain a hinge region which is apparently flexible.
Both the ssd chain and the Fr2 fragment of N-CAM are single
rods bent into arms approximately 18 and 10 nm long. The ld
and sd chains are longer bent rods that form rosettes
comprising two to six branches; detergent treatment disrupts
these rosettes into single rods. Specific antibodies that
block homophilic N-CAM binding labeled the distal ends of
the branches of the ld/sd rosettes and the ends of the
longer arm of both the ssd chain and the Fr2 fragment.
Antibodies that bind to the sialic acid-rich region of N-CAM
bound near the hinge. These data indicate that the N-CAM
rosettes are formed by interaction between their
transmembrane or cytoplasmic domains and not by interactions
involving their homophilic binding sites. The L-CAM Ft1
fragment is also a bent rod with an apparently flexible
hinge; like the ssd chain and the Fr2 fragment of N-CAM, it
does not form aggregates. The similarities between L-CAM and
N-CAM, despite their differences in amino acid sequence,
suggest that their general configuration and the presence of
a flexible hinge are important elements in assuring
effective and specific cell-cell adhesion.},
Key = {fds113191}
}
@article{fds113174,
Author = {K Anderson and FA Lai and QY Liu and E Rousseau and HP Erickson and G
Meissner},
Title = {Structural and functional characterization of the purified
cardiac ryanodine receptor-Ca2+ release channel
complex.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {264},
Number = {2},
Pages = {1329-35},
Year = {1989},
Month = {January},
ISSN = {0021-9258},
Keywords = {Animals • Calcium • Dogs • Heart Ventricles
• Ion Channels • Kinetics • Lipid Bilayers
• Molecular Weight • Muscles • Myocardium
• Organ Specificity • Receptors, Cholinergic
• Ryanodine • Ryanodine Receptor Calcium Release
Channel • Sarcoplasmic Reticulum • isolation &
purification • metabolism • metabolism*},
Abstract = {Using density gradient centrifugation and [3H]ryanodine as a
specific marker, the ryanodine receptor-Ca2+ release channel
complex from Chaps-solubilized canine cardiac sarcoplasmic
reticulum (SR) has been purified in the form of an
approximately 30 S complex, comprised of Mr approximately
400,000 polypeptides. Purification resulted in a specific
activity of approximately 450 pmol bound ryanodine/mg of
protein, a 60-70% recovery of ryanodine binding activity,
and retention of the high affinity ryanodine binding site
(KD = 3 nM). Negative stain electron microscopy revealed a
4-fold symmetric, four-leaf clover structure, which could
fill a box approximately 30 x 30 nm and was thus
morphologically similar to the SR-transverse-tubule,
junctionally associated foot structure. The structural,
sedimentation, and ryanodine binding data strongly suggest
there is one high affinity ryanodine binding site/30 S
complex, comprised of four Mr approximately 400,000
subunits. Upon reconstitution into planar lipid bilayers,
the purified complex exhibited a Ca2+ conductance (70 pS in
50 mM Ca2+) similar to that of the native cardiac Ca2+
release channel (75 pS). The reconstituted complex was also
found to conduct Na+ (550 pS in 500 mM Na+) and often to
display complex Na+ subconducting states. The purified
channel could be activated by micromolar Ca2+ or millimolar
ATP, inhibited by millimolar Mg2+ or micromolar ruthenium
red, and modified to a long-lived open subconducting state
by ryanodine. The sedimentation, subunit composition,
morphological, and ryanodine binding characteristics of the
purified cardiac ryanodine receptor-Ca2+ release channel
complex were similar to those previously described for the
purified ryanodine receptor-Ca2+ release channel complex
from fast-twitch skeletal muscle.},
Key = {fds113174}
}
@article{fds113202,
Author = {NA Carrell and HP Erickson and J McDonagh},
Title = {Electron microscopy and hydrodynamic properties of factor
XIII subunits.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {264},
Number = {1},
Pages = {551-6},
Year = {1989},
Month = {January},
ISSN = {0021-9258},
Keywords = {Centrifugation, Density Gradient • Chromatography, Gel
• Electrophoresis, Polyacrylamide Gel • Factor
XIII • Glutaral • Humans • Microscopy,
Electron • Models, Molecular • isolation &
purification • ultrastructure*},
Abstract = {Factor XIII is a transglutaminase important in blood
coagulation and fibrinolysis. Its function is to catalyze
peptide bond formation between the gamma-carboxamide group
of glutamines in one protein and the epsilon-amino group of
lysine in another. There are two zymogenic forms of factor
XIII: one is a noncovalent, intracellular dimer (A2); the
other is a noncovalent, extracellular tetramer (A2B2). The
catalytic function resides in the activated A chain (A2.).
Purified forms of factor XIII (A2B2, A2, A2.B2, B) were
prepared and analyzed by electron microscopy, gel
filtration, and gradient centrifugation. Hydrodynamic
constants were derived. Electron microscopy of
rotary-shadowed molecules showed A2 to consist of two
globular particles each about 6 x 9 nm in size. The A2 dimer
is significantly elongated, 18 nm long and 6 nm in diameter.
Sedimentation and gel filtration of the A2 dimer are
consistent with this asymmetric structure. B protein is a
filamentous, flexible strand with kinks, with a contour
length of 30 nm and a diameter of approximately 2-3 nm. The
sedimentation and gel filtration behavior of the B subunit
are characteristic of a highly asymmetric molecule. The
observed structure of the B subunit, combined with data for
its amino acid sequence, suggests a modular structure. The B
subunit is a member of a family of proteins composed of
tandem, repeating structures (referred to as GP-I domains);
the structure seen by electron microscopy for B subunit is
probably applicable to all proteins in this family. Plasma
and platelet factor XIII zymogens are tetrameric and
dimeric, but B protein, in the absence of A protein, appears
to be monomeric. Our model for the A2B2 zymogen has the
elongated A2 dimer forming the core and the two B strands
wrapping around the outside.},
Key = {fds113202}
}
@article{fds113141,
Author = {HP Erickson and MA Bourdon},
Title = {Tenascin: an extracellular matrix protein prominent in
specialized embryonic tissues and tumors.},
Journal = {Annual review of cell biology, UNITED STATES},
Volume = {5},
Pages = {71-92},
Year = {1989},
ISSN = {0743-4634},
Keywords = {Amino Acid Sequence • Animals • Cell Adhesion
Molecules, Neuronal • Embryonic and Fetal Development
• Extracellular Matrix • Humans • Neoplasm
Proteins • Protein Binding • Protein Conformation
• Tenascin • isolation & purification •
physiology • physiology* • secretion},
Key = {fds113141}
}
@article{fds113081,
Author = {MC Alliegro and CA Ettensohn and CA Burdsal and HP Erickson and DR
McClay},
Title = {Echinonectin: a new embryonic substrate adhesion
protein.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {107},
Number = {6 Pt 1},
Pages = {2319-27},
Year = {1988},
Month = {December},
ISSN = {0021-9525},
Keywords = {Animals • Antigens, Surface • Cell Adhesion
Molecules • Cell Adhesion* • Chromatography,
Affinity • Collagen • Extracellular Matrix •
Glycoproteins • Lectins • Microscopy, Electron
• Molecular Weight • Peptide Mapping • Sea
Urchins • analysis* • cytology* • immunology
• isolation & purification • isolation &
purification* • metabolism • physiology* •
ultrastructure},
Abstract = {An extracellular matrix molecule has been purified from sea
urchin (Lytechinus variegatus) embryos. Based on its
functional properties and on its origin, this glycoprotein
has been given the name "echinonectin." Echinonectin is a
230-kD dimer with a unique bow tie shape when viewed by
electron microscopy. The molecule is 12 nm long, 8 nm wide
at the ends, and narrows to approximately 4 nm at the
middle. It is composed of two 116-kD U-shaped subunits that
are attached to each other by disulfide bonds at their
respective apices. Polyclonal antibodies were used to
localize echinonectin in paraffin-embedded, sectioned
specimens by indirect immunofluorescence. The protein is
stored in vesicles or granules in unfertilized eggs, is
released after fertilization, and later becomes localized on
the apical surface of ectoderm cells in the embryo. When
used as a substrate in a quantitative in vitro assay,
echinonectin is highly effective as an adhesive substrate
for dissociated embryonic cells. Because of the quantity,
pattern of appearance, distribution, and adhesive
characteristics of this protein, we suggest that
echinonectin serves as a substrate adhesion molecule during
sea urchin development.},
Key = {fds113081}
}
@article{fds113110,
Author = {RA Walker and ET O'Brien and NK Pryer and MF Soboeiro and WA Voter and HP
Erickson, ED Salmon},
Title = {Dynamic instability of individual microtubules analyzed by
video light microscopy: rate constants and transition
frequencies.},
Journal = {The Journal of cell biology},
Volume = {107},
Number = {4},
Pages = {1437-48},
Year = {1988},
Month = {October},
ISSN = {0021-9525},
Keywords = {Animals • Guanosine Triphosphate • Kinetics •
Microtubules • Protein Binding • Swine •
Tubulin • Video Recording • physiology •
physiology* • ultrastructure},
Abstract = {We have developed video microscopy methods to visualize the
assembly and disassembly of individual microtubules at 33-ms
intervals. Porcine brain tubulin, free of
microtubule-associated proteins, was assembled onto axoneme
fragments at 37 degrees C, and the dynamic behavior of the
plus and minus ends of microtubules was analyzed for tubulin
concentrations between 7 and 15.5 microM. Elongation and
rapid shortening were distinctly different phases. At each
end, the elongation phase was characterized by a second
order association and a substantial first order dissociation
reaction. Association rate constants were 8.9 and 4.3
microM-1 s-1 for the plus and minus ends, respectively; and
the corresponding dissociation rate constants were 44 and 23
s-1. For both ends, the rate of tubulin dissociation equaled
the rate of tubulin association at 5 microM. The rate of
rapid shortening was similar at the two ends (plus = 733
s-1; minus = 915 s-1), and did not vary with tubulin
concentration. Transitions between phases were abrupt and
stochastic. As the tubulin concentration was increased,
catastrophe frequency decreased at both ends, and rescue
frequency increased dramatically at the minus end. This
resulted in fewer rapid shortening phases at higher tubulin
concentrations for both ends and shorter rapid shortening
phases at the minus end. At each concentration, the
frequency of catastrophe was slightly greater at the plus
end, and the frequency of rescue was greater at the minus
end. Our data demonstrate that microtubules assembled from
pure tubulin undergo dynamic instability over a twofold
range of tubulin concentrations, and that the dynamic
instability of the plus and minus ends of microtubules can
be significantly different. Our analysis indicates that this
difference could produce treadmilling, and establishes
general limits on the effectiveness of length redistribution
as a measure of dynamic instability. Our results are
consistent with the existence of a GTP cap during
elongation, but are not consistent with existing GTP cap
models.},
Language = {eng},
Key = {fds113110}
}
@article{fds113179,
Author = {FA Lai and HP Erickson and E Rousseau and QY Liu and G
Meissner},
Title = {Purification and reconstitution of the calcium release
channel from skeletal muscle.},
Journal = {Nature, ENGLAND},
Volume = {331},
Number = {6154},
Pages = {315-9},
Year = {1988},
Month = {January},
ISSN = {0028-0836},
Keywords = {Animals • Calcium • Ion Channels • Liposomes
• Membrane Potentials • Rabbits • Receptors,
Cholinergic • Ryanodine Receptor Calcium Release
Channel • Sarcoplasmic Reticulum • analysis*
• isolation & purification* • metabolism •
ultrastructure},
Abstract = {The calcium release channel from rabbit muscle sarcoplasmic
reticulum (SR) has been purified and reconstituted as a
functional unit in lipid bilayers. Electron microscopy
reveals the four-leaf clover structure previously described
for the 'feet' that span the transverse tubule (T)-SR
junction. Ca2+ release from the SR induced by T-system
depolarization during excitation-contraction coupling in
muscle may thus be effected through a direct association of
the T-system with SR Ca2+-release channels.},
Key = {fds113179}
}
@article{fds113185,
Author = {HP Erickson and HC Taylor},
Title = {Hexabrachion proteins in embryonic chicken tissues and human
tumors.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {105},
Number = {3},
Pages = {1387-94},
Year = {1987},
Month = {September},
ISSN = {0021-9525},
Keywords = {Animals • Cell Line • Cells, Cultured • Chick
Embryo • Fibroblasts • Glioma • Humans •
Microscopy, Electron • Molecular Weight • Protein
Conformation • Proteins • Skin • analysis
• analysis* • isolation & purification*},
Abstract = {Cell cultures of chicken embryo and human fibroblasts
produce a large extracellular matrix molecule with a
six-armed structure that we called a hexabrachion (Erickson,
H. P., and J. L. Iglesias, 1984, Nature (Lond.),
311:267-269. In the present work we have determined that the
myotendinous (M1) antigen described by M. Chiquet and D. M.
Fambrough in chicken tissues (1984, J. Cell Biol.,
98:1926-1936), and the glioma mesenchymal extracellular
matrix protein described by Bourdon et al. in human tumors
(Bourdon, M. A., C. J. Wikstrand, H. Furthmayr, T. J.
Matthews, and D. D. Bigner, 1983, Cancer Res. 43:2796-2805)
have the structure of hexabrachions. We also demonstrate
that the M1 antigen is present in embryonic brain, where it
was previously reported absent, and have purified
hexabrachions from brain homogenates. The recently described
cytotactin (Grumet, M., S. Hoffman, K. L. Crossin, and G. M.
Edelman, 1985, Proc. Natl. Acad. Sci. USA, 82:8075-8079) now
appears to be identical to the chicken hexabrachion protein.
In a search for functional roles, we looked for a possible
cell attachment activity. A strong, fibronectin-like
attachment activity was present in (NH4)2SO4 precipitates of
cell supernatant and sedimented with hexabrachions in
glycerol gradients. Hexabrachions purified by antibody
adsorption, however, had lost this activity, suggesting that
it was due to a separate factor associated with
hexabrachions in the gradient fractions. The combined
information in the several, previously unrelated studies
suggests that hexabrachions may play a role in organizing
localized regions of extracellular matrix. The protein is
prominently expressed at specific times and locations during
embryonic development, is retained in certain adult tissues,
and is reexpressed in a variety of tumors.},
Key = {fds113185}
}
@article{fds113098,
Author = {ET O'Brien and WA Voter and HP Erickson},
Title = {GTP hydrolysis during microtubule assembly.},
Journal = {Biochemistry, UNITED STATES},
Volume = {26},
Number = {13},
Pages = {4148-56},
Year = {1987},
Month = {June},
ISSN = {0006-2960},
Keywords = {Animals • Buffers • Chromatography, High Pressure
Liquid • Glycerol • Guanosine Diphosphate •
Guanosine Triphosphate • Hydrolysis • Methods
• Microtubules • Molybdenum • Phosphoric
Acids • Phosphorus Radioisotopes • Swine •
Time Factors • Tubulin • analysis •
diagnostic use • isolation & purification •
metabolism* • pharmacology • physiology*},
Abstract = {The GTP cap model of dynamic instability [Mitchison, T., &
Kirschner, M.W. (1984) Nature (London) 312, 237] postulates
that a GTP cap at the end of most microtubules stabilizes
the polymer and allows continuing assembly of GTP-tubulin
subunits while microtubules without a cap rapidly
disassemble. This attractive explanation for observed
microtubule behavior is based on the suggestion that
hydrolysis of GTP is not coupled to assembly but rather
takes place as a first-order reaction after a subunit is
assembled onto a polymer end. Carlier and Pantaloni
[Carlier, M., & Pantaloni, D. (1981) Biochemistry 20, 1918]
reported a lag of hydrolysis behind microtubule assembly and
a first-order rate constant for hydrolysis (kh) of 0.25/min.
A lag has not been demonstrated by other investigators, and
a kh value that specifies such a slow rate of hydrolysis is
difficult to reconcile with reported steady-state
microtubule growth rates and frequencies of disassembly. We
have looked for a lag using tubulin free of
microtubule-associated protein at concentrations of 18.5-74
microM, assembly with and without glycerol, and two
independent assays of GTP hydrolysis. No lag was observed
under any of the conditions employed, with initial rates of
hydrolysis increasing in proportion to rates of assembly. If
hydrolysis is uncoupled from assembly, we estimate that kh
must be at least 2.5/min and could be much greater, a result
that we argue may be advantageous to the GTP cap model. We
also describe a preliminary model of assembly coupled to
hydrolysis that specifies formation and loss of a GTP cap,
thus allowing dynamic instability.},
Key = {fds113098}
}
@article{fds113147,
Author = {WA Voter and C Lucaveche and AE Blaurock and HP Erickson},
Title = {Lateral packing of protofibrils in fibrin fibers and
fibrinogen polymers.},
Journal = {Biopolymers, UNITED STATES},
Volume = {25},
Number = {12},
Pages = {2359-73},
Year = {1986},
Month = {December},
ISSN = {0006-3525},
Keywords = {Animals • Cattle • Fibrin • Fibrinogen •
Macromolecular Substances • Microscopy, Electron •
Protein Conformation • genetics •
metabolism*},
Key = {fds113147}
}
@article{fds113171,
Author = {WA Voter and C Lucaveche and HP Erickson},
Title = {Concentration of protein in fibrin fibers and fibrinogen
polymers determined by refractive index matching.},
Journal = {Biopolymers, UNITED STATES},
Volume = {25},
Number = {12},
Pages = {2375-84},
Year = {1986},
Month = {December},
ISSN = {0006-3525},
Keywords = {Animals • Cattle • Fibrin • Fibrinogen •
Hemocyanin • Microscopy, Electron • Protein
Conformation • metabolism*},
Key = {fds113171}
}
@article{fds113137,
Author = {LJ Fretto and WE Fowler and DR McCaslin and HP Erickson and PA
McKee},
Title = {Substructure of human von Willebrand factor. Proteolysis by
V8 and characterization of two functional
domains.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {261},
Number = {33},
Pages = {15679-89},
Year = {1986},
Month = {November},
ISSN = {0021-9258},
Keywords = {Amino Acid Sequence • Amino Acids •
Centrifugation, Density Gradient • Chromatography
• Electrophoresis, Polyacrylamide Gel •
Endopeptidases • Heparin • Macromolecular
Substances • Microscopy, Electron • Molecular
Weight • Peptide Fragments • Platelet Aggregation
• Protein Conformation • Serine Endopeptidases*
• analysis • drug effects • metabolism •
metabolism* • pharmacology • von Willebrand
Factor},
Abstract = {The effects of Staphylococcus aureus V8 protease (V8) on the
multimeric structure of human von Willebrand factor (vWF)
were studied to test and expand our model for the
substructure of vWF. Electron microscopy of V8 digests of
vWF revealed that the multimers were cleaved where the
flexible rod (R) domains join the large elongated globular
(G) domains. The resulting two major fragments, which were
purified by affinity and hydrophobic interaction
chromatography and by glycerol-gradient ultracentrifugation,
are disulfide-linked homodimers of these domains (i.e. RR
and GG) and are morphologically identical to the alternating
RR and GG domains of intact vWF. The glycoprotein fragment
GG (6.5 X 35 nm) has mass 343 kDa by sedimentation
equilibrium and the amino-terminal sequence of intact plasma
vWF. It contains the binding site for heparin within 300
residues of its amino terminus and a separate site for the
platelet GPIb receptor responsible for platelet
agglutination in the presence of ristocetin. With
approximately 18% alpha-helix and approximately 15%
beta-pleated sheet, fragment GG accounts for most of the
ordered secondary structure present in whole vWF. The two
thin flexible rod domains (1.8-2.0 X 30-34 nm) of fragment
RR are joined at a small central nodule (approximately 5 nm
diameter) and also have a small nodule at each free end.
Fragment RR contains an extraordinarily high cystine
content, lower than average amounts of other hydrophobic
residues, and essentially no alpha-helix, as judged by
circular dichroism. The amino-terminal sequence and amino
acid composition of fragment RR corresponded to that of the
COOH-terminal 685 residues of the intact vWF subunit
(Titani, K., Kumar, S., Takio, K., Ericsson, L. H., Wade, R.
D., Ashida, K., Walsh, K. A., Chopek, M. W., Sadler, J. E.,
and Fujikawa, K. (1986) Biochemistry 25, 3171-3184). This
sequence analysis gives a mass of 180 kDa for glycosylated
fragment RR, somewhat higher than the 130 kDa we obtained by
sedimentation equilibrium. Our sequence analysis of a
110-kDa plasmic vWF peptide also permitted identification of
a major plasmin cleavage site 705 residues from the COOH
terminus and a half-cystine residue (1360) involved in
maintaining the multimeric structure of plasmin-degraded
vWF.(ABSTRACT TRUNCATED AT 400 WORDS)},
Key = {fds113137}
}
@article{fds113181,
Author = {HP Erickson},
Title = {Nucleosome structure.},
Journal = {Science (New York, N.Y.), UNITED STATES},
Volume = {233},
Number = {4771},
Pages = {1429-31},
Year = {1986},
Month = {September},
ISSN = {0036-8075},
Keywords = {DNA, Superhelical • Nucleic Acid Conformation •
Nucleosomes • ultrastructure*},
Key = {fds113181}
}
@article{fds113120,
Author = {HP Erickson and WA Voter},
Title = {Nucleation of microtubule assembly. Experimental kinetics,
computer fitting of models, and observations on tubulin
rings.},
Journal = {Annals of the New York Academy of Sciences, UNITED
STATES},
Volume = {466},
Pages = {552-65},
Year = {1986},
ISSN = {0077-8923},
Keywords = {Animals • Computers • Hemoglobin, Sickle •
Humans • Kinetics • Macromolecular Substances
• Microscopy, Electron • Microtubules •
Models, Molecular • Tubulin • metabolism •
metabolism* • ultrastructure},
Key = {fds113120}
}
@article{fds113195,
Author = {WE Fowler and LJ Fretto and KK Hamilton and HP Erickson and PA
McKee},
Title = {Substructure of human von Willebrand factor.},
Journal = {The Journal of clinical investigation, UNITED
STATES},
Volume = {76},
Number = {4},
Pages = {1491-500},
Year = {1985},
Month = {October},
ISSN = {0021-9738},
Keywords = {Chromatography, Gel • Electrophoresis, Polyacrylamide
Gel • Humans • Microscopy, Electron •
Peptides • Plasmin • Protein Conformation •
analysis • analysis* • isolation & purification
• von Willebrand Factor},
Abstract = {Using electron microscopy, we have visualized the
substructure of human von Willebrand factor (vWf) purified
by two different approaches. vWf multimers, which appear as
flexible strands varying in length up to 2 micron, consist
of dimeric units (protomers) polymerized linearly in an
end-to-end fashion through disulfide bonds. Examination of
small multimers (e.g., one-mers, two-mers, and three-mers)
suggests that each protomer consists of two large globular
end domains (22 X 6.5 nm) connected to a small central node
(6.4 X 3.4 nm) by two flexible rod domains each
approximately 34 nm long and approximately 2 nm in diameter.
The protomer is 120 nm in length when fully extended. These
same structural features are seen both in vWf molecules that
were rapidly purified from fresh plasma by a new two-step
procedure and in those purified from lyophilized
intermediate-purity Factor VIII/vWf concentrates. The
240,000-mol wt subunit observed by gel electrophoresis upon
complete reduction of vWf apparently contains both a rod
domain and a globular domain and corresponds to one half of
the protomer. Two subunits are disulfide-linked, probably
near their carboxyl termini, to form the protomer; disulfide
bonds in the amino-terminal globular ends link promoters to
form vWf multimers. The vWf multimer strands have at least
two morphologically distinct types of ends, which may result
from proteolytic cleavage in the globular domains after
formation of large linear polymers. In addition to releasing
fragments that were similar in size and shape to the
repeating protomeric unit, plasmic degradation of either
preparation of vWf reduced the size of multimers, but had no
detectable effect on the substructure of internal
protomers.},
Key = {fds113195}
}
@article{fds113219,
Author = {LM Milam and HP Erickson},
Title = {A structural comparison of tryptic fragments of three types
of intermediate filaments.},
Journal = {Journal of ultrastructure research, UNITED
STATES},
Volume = {90},
Number = {3},
Pages = {251-60},
Year = {1985},
Month = {March},
ISSN = {0022-5320},
Keywords = {Animals • Cattle • Chromatography, Gel •
Cytoskeleton • Desmin • Hydrolysis •
Intermediate Filament Proteins • Intermediate Filaments
• Keratins • Microscopy, Electron • Molecular
Weight • Peptide Fragments • Spinal Cord •
Trypsin • analysis • analysis* •
ultrastructure • ultrastructure*},
Abstract = {We have compared tryptic fragments of three types of
intermediate filaments, emphasizing structural
characteristics as seen in the electron microscope.
Variable, long alpha-helical rod fragments were found to be
similar for keratin, neurofilaments and desmin filaments.
Short rod fragments from keratin and neurofilaments appeared
similar when observed by electron microscopy. Short rod
fragments were not seen in desmin filament digests. In
addition to these elongated particles, globular fragments,
which have not been described previously, were obtained from
all three types of intermediate filaments. These globular
fragments were characterized by gel filtration and electron
microscopy, and compared to globular proteins of known size
using both methods. The diameter was about 6 nm and the
molecular weight was estimated to be 50 000-60 000. These
globular particles may comprise the short, nonhelical
regions from several IF protein subunits, which are
clustered into an interface in the intact filament or
protofilaments.},
Key = {fds113219}
}
@article{fds113218,
Author = {NA Carrell and LA Fitzgerald and B Steiner and HP Erickson and DR
Phillips},
Title = {Structure of human platelet membrane glycoproteins IIb and
IIIa as determined by electron microscopy.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {260},
Number = {3},
Pages = {1743-9},
Year = {1985},
Month = {February},
ISSN = {0021-9258},
Keywords = {Amino Acids • Blood Platelets • Calcium •
Cell Membrane • Centrifugation, Density Gradient •
Chromatography, High Pressure Liquid • Edetic Acid
• Glycoproteins • Humans • Macromolecular
Substances • Membrane Proteins • Microscopy,
Electron • Octoxynol • Platelet Membrane
Glycoproteins • Polyethylene Glycols • analysis
• analysis* • blood* • metabolism •
pharmacology},
Abstract = {The glycoprotein (GP) IIb-IIIa complex was isolated from
human platelet membranes and examined for glycoprotein
stoichiometry and morphology. To determine the ratio of
glycoproteins in the complex, the isolated glycoproteins
were solubilized with sodium dodecyl sulfate and separated
by high-performance liquid chromatography. Quantitative
amino acid analysis of individual glycoproteins showed that
the ratio of GP IIb to GP IIIa in the Ca2+-dependent complex
was 0.93:1. Morphology was determined by electron microscopy
of rotary-shadowed and negatively stained specimens.
Individual complexes consisted of two domains: an oblong
head of approximately 8 X 10 nm with two rodlike tails
extending approximately 14-17 nm from one side of the head.
Treatment of the isolated complex with EDTA resulted in the
appearance of a mixture of oblong and filamentous
structures, which could be separated by a sucrose gradient
sedimentation in Triton X-100. As seen by rotary and
unidirectional shadowing, GP IIb was a compact structure,
approximately 8 X 10 nm in size. Isolated GP IIIa was more
heterogeneous but was most often observed in an elongated
form, varying in length from 20 to 30 nm and in width from 2
to 3 nm. By comparing these structures to that of the
heterodimer complex, it was determined that the oblong
domain was GP IIb and the rodlike tails were GP IIIa. Each
milligram of isolated GP IIb-IIIa complex bound 0.30 mg of
[3H]Triton X-100, indicating that the glycoprotein complex
contained limited hydrophobic domains. Upon removal of
detergent, GP IIb-IIIa complexes formed aggregates that
sedimented in sucrose gradients as a diffuse peak ranging
from 14 to 32 s. Examination of these aggregates by electron
microscopy showed that they were composed of clusters or
"rosettes" of 2 to 20 or more of the GP IIb-IIIa complexes.
The orientation of these rosettes was such that the tails
were joined in the center, with the head portions directed
away from the interacting tails. It thus appears that the
primary hydrophobic domains of the GP IIb-IIIa complex exist
at the tips of the GP IIIa tails. Because the GP IIb-IIIa
complex is an intrinsic membrane glycoprotein, these
findings indicate a potential membrane attachment site for
the GP IIb-IIIa complexes.},
Key = {fds113218}
}
@article{fds113209,
Author = {HP Erickson and JL Inglesias},
Title = {A six-armed oligomer isolated from cell surface fibronectin
preparations.},
Journal = {Nature},
Volume = {311},
Number = {5983},
Pages = {267-9},
Year = {1984},
Month = {November},
ISSN = {0028-0836},
Keywords = {Cell Adhesion • Extracellular Matrix •
Fibronectins* • Humans • Macromolecular Substances
• Microscopy, Electron • ultrastructure},
Abstract = {Fibronectins are adhesive glycoproteins thought to mediate
the attachment of cells to various substrates. Plasma
fibronectin (PFN) is a dimer comprising subunits of
molecular weight 220,000, connected by one or two disulphide
bonds. Electron microscopy shows that PFN is a long,
flexible strand, 2-3 nm in diameter and 140 nm long. Many
cells in tissue culture elaborate an extracellular matrix of
insoluble (highly cross-linked by disulphide bonds)
fibronectin, and a variable amount of 'cell surface
fibronectin' (CSFN) that can be extracted by mild urea
treatment. This CSFN, soluble in 1 M urea and at high pH, is
a mixture of dimers and disulphide-bonded oligomers. In the
present study we have examined the structure of these
molecules by electron microscopy. Oligomers were separated
from dimers and contaminating proteins by zone sedimentation
through glycerol gradients. We report that the CSFN dimers
are identical in structure to PFN. In contrast, the
oligomers have an elaborate and well defined structure that
we call a 'hexabrachion': six arms emanating from a central
globular particle. The arms are similar to PFN in being
long, thin and flexible, but have several distinctly
different features.},
Language = {eng},
Key = {fds113209}
}
@article{fds113106,
Author = {L Milam and HP Erickson},
Title = {Structural characteristics of the desmin
protofilament.},
Journal = {Journal of ultrastructure research, UNITED
STATES},
Volume = {89},
Number = {2},
Pages = {179-86},
Year = {1984},
Month = {November},
ISSN = {0022-5320},
Keywords = {Animals • Chickens • Chromatography, Gel •
Cytoskeleton • Desmin • Intermediate Filaments
• Microscopy, Electron • Molecular Weight •
physiology* • ultrastructure*},
Abstract = {Biochemical investigations of intermediate filaments in
soluble or partially assembled forms are often difficult to
perform due to the unusual insolubility of most types of
intermediate filaments. However, desmin is soluble in 10 mM
Tris. The structure of partially soluble native desmin was
studied by gel-filtration chromatography and electron
microscopy. The lowest molecular weight species of soluble
desmin is a flexible rod averaging 53 nm in length.
Calculations of f/fmin values from a previously published
sedimentation value allowed comparisons with other elongated
proteins. These values and the dimensions obtained from
electron microscopy suggest that the desmin protofilament
contains three or four protein subunits.},
Key = {fds113106}
}
@article{fds113114,
Author = {WA Voter and HP Erickson},
Title = {The kinetics of microtubule assembly. Evidence for a
two-stage nucleation mechanism.},
Journal = {The Journal of biological chemistry},
Volume = {259},
Number = {16},
Pages = {10430-8},
Year = {1984},
Month = {August},
ISSN = {0021-9258},
Keywords = {Animals • Guanosine Triphosphate • Kinetics •
Macromolecular Substances • Microscopy, Electron •
Microtubule-Associated Proteins • Microtubules •
Models, Structural • Nerve Tissue Proteins •
Proteins • Tubulin • metabolism • metabolism*
• ultrastructure*},
Abstract = {A model describing the nucleation and assembly of purified
tubulin has been developed. The novel feature of this model
is a two stage nucleation process to allow the explicit
inclusion of the two-dimensional nature of the early stages
of microtubule assembly. In actin assembly the small
starting nucleus has only one site for subunit addition as
the two-stranded helix is formed. In contrast, microtubule
assembly begins with the formation of a small
two-dimensional section of microtubule wall. The model we
propose is a modification of the work of Wegner and Engel
(Wegner, A., and Engel, J. (1975) Biophys. Chem. 3, 215-225)
wherein we add a second stage of nucleation to directly
account for lateral growth, i.e. the addition of a small
number of subunits to the side of an existing sheet
structure. Subsequent elongation of the sheets is treated in
the usual way. The experimental system used to test this
model was the Mg2+/glycerol induced assembly of purified
tubulin. The computer simulation of the polymerization time
courses gave a fairly good fit to experimental kinetics for
our model, where the primary nucleus comprises two
protofilaments, of four and three subunits, and lateral
growth requires a three-subunit nucleus to initiate a new
protofilament.},
Language = {eng},
Key = {fds113114}
}
@article{fds113126,
Author = {HP Erickson and NA Carrell},
Title = {Fibronectin in extended and compact conformations. Electron
microscopy and sedimentation analysis.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {258},
Number = {23},
Pages = {14539-44},
Year = {1983},
Month = {December},
ISSN = {0021-9258},
Keywords = {Centrifugation, Density Gradient • Fibronectins* •
Humans • Microscopy, Electron • Osmolar
Concentration • Peptide Fragments • Protein
Conformation • analysis},
Abstract = {We have studied the ionic strength-dependent change in
conformation of fibronectin, half-molecules of fibronectin
produced by reduction and carboxyamidomethylation, and
proteolytic fragments. In zone sedimentation through
glycerol gradients, intact fibronectin sedimented at 13.5
and 10 S in 0.02 and 0.2 M NaCl, respectively, in agreement
with previous studies. Half-molecules sedimented at 11.5 and
7.5 S in the two salt concentrations, demonstrating that the
change in conformation occurs independently within each
half-molecule. Gelatin-binding plasmic fragments of 165-215
kDa showed a similar large shift in sedimentation
coefficient, and one of 60 kDa showed a small shift. We
conclude that the change in conformation is effected by
short range electrostatic interactions along the strand,
rather than by attraction of distant segments of the
molecule. Electron microscopy showed that both intact
fibronectin and half-molecules exist as extended strands at
high ionic strength. At low ionic strength the strands are
more strongly curved or bent to produce an irregularly
coiled compact structure. No regular points of folding or
crossover were seen, suggesting that the compact
conformation is produced by increased bending over most or
all of the strand.},
Key = {fds113126}
}
@article{fds113080,
Author = {HP Erickson and WE Fowler},
Title = {Electron microscopy of fibrinogen, its plasmic fragments and
small polymers.},
Journal = {Annals of the New York Academy of Sciences, UNITED
STATES},
Volume = {408},
Pages = {146-63},
Year = {1983},
Month = {June},
ISSN = {0077-8923},
Keywords = {Chemistry, Physical • Fibrin • Fibrinogen •
Fibronectins • Humans • Microscopy, Electron
• Peptide Fragments • Polymers • analysis
• analysis* • metabolism},
Key = {fds113080}
}
@article{fds113092,
Author = {HR Brown and HP Erickson},
Title = {Assembly of proteolytically cleaved tubulin.},
Journal = {Archives of biochemistry and biophysics, UNITED
STATES},
Volume = {220},
Number = {1},
Pages = {46-51},
Year = {1983},
Month = {January},
ISSN = {0003-9861},
Keywords = {Binding Sites • Buffers • Chemistry • Peptide
Hydrolases* • Protein Binding •
Tubulin*},
Abstract = {Conditions have been found for limited proteolysis of
purified tubulin, in which 70-90% of the molecules are
cleaved at one or two sites. Thermolysin and chymotrypsin
cleave the alpha and beta subunits, respectively, at single
sites. Trypsin cleaves the alpha subunit at two sites. The
chymotrypsin site and one of the trypsin sites are
apparently inaccessible on assembled microtubules. The
different samples of proteolyzed tubulin were all fully
competent to assemble in a buffer containing 1 M sodium
glutamate. In another buffer (50 mM morpholinoethanesulfonic
acid, 3.4 M glycerol) tubulin digested by thermolysin
assembled as well as native tubulin, but samples digested by
chymotrypsin or trypsin would not assemble even at high
protein concentrations.},
Key = {fds113092}
}
@article{fds113172,
Author = {K Ohmori and LJ Fretto and RL Harrison and ME Switzer and HP Erickson and PA McKee},
Title = {Electron microscopy of human factor VIII/Von Willebrand
glycoprotein: effect of reducing reagents on structure and
function.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {95},
Number = {2 Pt 1},
Pages = {632-40},
Year = {1982},
Month = {November},
ISSN = {0021-9525},
Keywords = {Alkylation • Blood Coagulation Factors* • Blood
Platelets • Dithiothreitol • Factor VIII* •
Humans • Macromolecular Substances •
Mercaptoethanol • Microscopy, Electron • Molecular
Weight • Platelet Aggregation • Protein
Conformation • Ristocetin • Structure-Activity
Relationship • metabolism • pharmacology •
pharmacology* • physiology • von Willebrand
Factor*},
Abstract = {The structure of native and progressively reduced human
factor VIII/von Willebrand factor (FVIII/vWF) was examined
by electron microscopy and SDS gel electrophoresis and then
correlated with its biological activities. Highly resolved
electron micrographs of well-spaced, rotary-shadowed
FVIII/vWF molecules showed their structure to consist of a
very flexible filament that contains irregularly spaced
small nodules. Filaments ranged from 50 to 1,150 nm with a
mean length of 478 nm and lacked fixed, large globular
domains as seen in fibrinogen and IgM. A population of
multimeric FVIII/vWF species ranging in molecular weight
from 1 to 5 million daltons and differing in size
alternately by one and two subunits was observed on SDS-2%
polyacrylamide-0.5% agarose gel electrophoresis. With
progressive reduction of disulfide bonds by dithiothreitol
(DTT), the electron microscopic size of FVIII/vWF decreased
in parallel with increased electrophoretic mobility on
SDS-agarose gels; between 0.1 and 0.5 mM DTT its structure
changed from predominantly fibrillar species to large
nodular forms. A 50% loss of vWF specific activity and FVIII
procoagulant activity occurred at 0.4 mM DTT and 1 mM DTT,
respectively, corresponding to the reduction of 4 and 12
disulfide bonds of the 62 disulfides per 200,000-dalton
subunit. We conclude that reduction of a few critical
disulfide bonds results in a major structural change by
electron microscopy and a concomitant loss of approximately
50% of the vWF function.},
Key = {fds113172}
}
@article{fds113186,
Author = {WA Voter and HP Erickson},
Title = {Electron microscopy of MAP 2 (microtubule-associated protein
2).},
Journal = {Journal of ultrastructure research, UNITED
STATES},
Volume = {80},
Number = {3},
Pages = {374-82},
Year = {1982},
Month = {September},
ISSN = {0022-5320},
Keywords = {Animals • Brain Chemistry • Chemistry •
Chromatography, Ion Exchange • Circular Dichroism
• Electrophoresis, Polyacrylamide Gel • Heat
• Microscopy, Electron • Microtubule-Associated
Proteins • Microtubules • Molecular Weight •
Proteins • Swine • analysis* • isolation &
purification • ultrastructure*},
Key = {fds113186}
}
@article{fds113215,
Author = {L Milam and HP Erickson},
Title = {Visualization of a 21-nm axial periodicity in shadowed
keratin filaments and neurofilaments.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {94},
Number = {3},
Pages = {592-6},
Year = {1982},
Month = {September},
ISSN = {0021-9525},
Keywords = {Animals • Cattle • Cytoskeleton • Keratins*
• Microscopy, Electron • ultrastructure*},
Abstract = {Unidirectional and rotary shadowing techniques have been
applied in studying the surface structure of two types of
intermediate filaments. Keratin filaments and neurofilaments
demonstrate a approximately 21-nm axial periodicity which
probably indicates the helical pitch of the outer shell of
the filament. Analysis of unidirectionally shadowed keratin
showed that the helix is left-handed. The observation of a
left-handed helix of 21-nm pitch supports the three-stranded
protofilament model of Fraser, Macrae, and Suzuki (1976, J.
Mol. Biol. 108:435-452), and indicates that keratin
filaments probably consist of 10 three-stranded
protofilaments surrounding a core of three such
protofilaments, as predicted by models based on x-ray
diffraction of hard keratin filaments. Neurofilaments do not
demonstrate an easily identifiable hand, so their
consistency with the model is, as yet, uncertain.},
Key = {fds113215}
}
@article{fds113216,
Author = {HP Erickson and N Carrell and J McDonagh},
Title = {Fibronectin molecule visualized in electron microscopy: a
long, thin, flexible strand.},
Journal = {The Journal of cell biology, UNITED STATES},
Volume = {91},
Number = {3 Pt 1},
Pages = {673-78},
Year = {1981},
Month = {December},
ISSN = {0021-9525},
Keywords = {Binding Sites • Fibrinogen* • Fibronectins •
Humans • Macromolecular Substances • Microscopy,
Electron • Molecular Weight • Motion •
Protein Conformation},
Abstract = {We have determined the structure of plasma fibronectin by
electron microscopy of shadowed specimens. the 440,000
molecular weight, dimeric molecule appears to be a long,
thin, highly flexible strand. The contour length of the most
extended molecules is 160 nm, but a distribution of lengths
down to 120 nm was observed, indicating flexibility in
extension as well as in bending. The average diameter of the
strand is 2 nm and there are no large globular domains. the
large fragments produced by limited digestion with plasmin
are not globular domains but are segments of the strand,
whose length corresponds to the molecular weight of the
polypeptide chain. We conclude that each polypeptide chain
of the dimeric molecule spans half the length of the strand,
with their carboxyl termini joined at the center of the
strand and their amino termini at the ends. This model is
supported by images of fibronectin-fibrinogen complexes, in
which the fibrinogen is always attached to an end of the
fibronectin strand.},
Key = {fds113216}
}
@article{fds113102,
Author = {LK Hesterberg and JC Lee and HP Erickson},
Title = {Structural properties of an active form of rabbit muscle
phosphofructokinase.},
Journal = {The Journal of biological chemistry, UNITED
STATES},
Volume = {256},
Number = {18},
Pages = {9724-30},
Year = {1981},
Month = {September},
ISSN = {0021-9258},
Keywords = {Adenylyl Imidodiphosphate • Animals • Kinetics
• Macromolecular Substances • Microscopy, Electron
• Models, Molecular • Muscles •
Phosphofructokinase-1 • Protein Conformation •
Rabbits • enzymology* • metabolism* •
pharmacology},
Abstract = {The quaternary structure of an active form of rabbit muscle
phosphofructokinase was studied by sedimentation and
electron microscopy. Active enzyme centrifugation studies at
pH 7.0 and 23 +/- 1 degrees C showed that
phosphofructokinase sediments as a single component with a
sedimentation coefficient of 12.2 +/- 0.5 S. Identical
results were obtained in two assay and three solvent
systems. Boundary sedimentation studies of
phosphofructokinase in the presence of 1.0 mM fructose
6-phosphate, 0.1 mM adenylyl imidodiphosphate at pH 7.0 and
23 +/- 1 degrees C were performed. The results showed that
the sedimentation coefficient of phosphofructokinase remains
constant within the range of protein concentration studied
and assumes a value of 12.4 S. The molecular weights of the
subunit and the 12.4 S component were measured by
sedimentation equilibrium yielding values of 83,000 and
330,000 for the monomeric and polymeric species,
respectively. It is, therefore, concluded that the active
form of phosphofructokinase is indeed the tetrameric
species. The structure of the phosphofructokinase tetramer
was also studied by electron microscopy of negatively
stained specimens. Particles identified as tetramers
measured approximately 9 nm in diameter by 14 nm in length.
The observed size and shape are consistent with the
hydrodynamic measurements. Structural features within the
tetramer were interpreted as due to the four individual
subunits, each one approximately 4 X 6 X 6 nm in size,
arranged with D2 symmetry.},
Key = {fds113102}
}
@article{fds113211,
Author = {WE Fowler and RR Hantgan and J Hermans and HP Erickson},
Title = {Structure of the fibrin protofibril.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America, UNITED STATES},
Volume = {78},
Number = {8},
Pages = {4872-6},
Year = {1981},
Month = {August},
ISSN = {0027-8424},
Keywords = {Fibrin* • Humans • Macromolecular Substances
• Microscopy, Electron • Models, Biological •
Protein Binding},
Abstract = {We identified the two-stranded fibrin protofibril and
studied its structure in electron micrographs of negatively
stained specimens. Based on these images and on
considerations of symmetry, we constructed a model of the
protofibril in which the two strands of trinodular fibrin
molecules are related by a two-fold screw axis between the
strands and two-fold axes perpendicular to them. The two
strands are held together by staggered lateral contacts
between the central nodules of one strand and outer nodules
of the other. The molecules within a strand are joined by
longitudinal contacts between outer nodules. This
interpretation of the structure of protofibrils is supported
by images of trimer complexes whose preparation and
structure are described here, in which the central nodule of
a fibrin monomer is attached to the crosslinked outer
nodules of two other molecules. We conclude that the
association of protofibrils to form thicker fibers must
involve a second type of lateral contact, probably between
outer nodules of adjacent, in-register strands. In total, we
identify three intermolecular contacts involved in the
polymerization of fibrin.},
Key = {fds113211}
}
@article{fds113075,
Author = {HP Erickson and D Pantaloni},
Title = {The role of subunit entropy in cooperative assembly.
Nucleation of microtubules and other two-dimensional
polymers.},
Journal = {Biophysical journal, UNITED STATES},
Volume = {34},
Number = {2},
Pages = {293-309},
Year = {1981},
Month = {May},
ISSN = {0006-3495},
Keywords = {Animals • Kinetics • Macromolecular Substances
• Mathematics • Microtubules • Models,
Biological • Thermodynamics • ultrastructure*},
Abstract = {The self-assembly and nucleation of two-dimensional polymers
is described by a theory based on a model of rigid subunits
and bonds and simple principles of thermodynamics. The key
point in the theory is to separate as an explicit parameter
the free energy, primarily attributed to the entropy of the
free subunit, that is required to immobilize a subunit in
the polymer. Quantitative relations for the association of a
subunit forming a longitudinal bond, a lateral bone, or both
together are obtained, which demonstrate the basis and
magnitude of cooperativity. The same formalism leads to a
quantitative estimate for th concentration of the small
polymers that are important intermediates in nucleation. It
is shown that, if the concentration of free subunits is
below a certain "critical supersaturation," the
concentration of some essential intermediates is too low to
support any significant assembly and nucleation is blocked.
If the subunit concentration is above the critical
supersaturation, all of the small intermediates are
sufficiently stable to form and grow spontaneously. The
theory predicts a critical supersaturation of 3.5 to 7 (the
ratio of subunit concentration to the equilibrium
solubility) for parameters appropriate to assembly of the
microtubule wall. Experimentally, nucleation and assembly of
microtubules is obtained at somewhat lower concentrations,
1.5 to 3 times the equilibrium solubility. Special
mechanisms that could stabilize small polymers and
facilitate nucleation of microtubule assembly are
suggested.},
Key = {fds113075}
}
@article{fds113154,
Author = {WE Fowler and HP Erickson and RR Hantgan and J McDonagh and J
Hermans},
Title = {Cross-linked fibrinogen dimers demonstrate a feature of the
molecular packing in fibrin fibers.},
Journal = {Science (New York, N.Y.), UNITED STATES},
Volume = {211},
Number = {4479},
Pages = {287-9},
Year = {1981},
Month = {January},
ISSN = {0036-8075},
Keywords = {Factor XIII • Fibrin* • Fibrinogen* • Humans
• Macromolecular Substances • Microscopy, Electron
• Protein Conformation • gamma-Glutamyltransferase
• metabolism},
Key = {fds113154}
}
@article{fds113222,
Author = {WE Fowler and LJ Fretto and HP Erickson and PA McKee},
Title = {Electron microsocpy of plasmic fragments of human fibrinogen
as related to trinodular structure of the intact
molecule.},
Journal = {The Journal of clinical investigation, UNITED
STATES},
Volume = {66},
Number = {1},
Pages = {50-6},
Year = {1980},
Month = {July},
ISSN = {0021-9738},
Keywords = {Electrophoresis, Polyacrylamide Gel • Fibrinogen •
Humans • Microscopy, Electron • Optical Rotatory
Dispersion • Sodium Dodecyl Sulfate •
Structure-Activity Relationship • analysis* •
methods},
Abstract = {We have examined rotary shadowed, purified plasmic fragments
of human fibrinogen with the electron microscope and have
determined the relation of these fragments to the intact
fibrinogen molecule. Both intact fibrinogen and its earliest
cleavage product, fragment X, are trinodular. The next
largest product, fragment Y, consists of two linked nodules.
The two terminal products, fragments D and E, are single
nodules. From measurements of simultaneously shadowed
specimens of these different species, we conclude that the
outer nodules of the trinodular fibrinogen molecule are the
fragment D-containing regions and the central nodule is the
fragment E-containing region.},
Key = {fds113222}
}
@article{fds113083,
Author = {HP Erickson},
Title = {Thermodynamic and kinetic aspects of assembly.},
Journal = {Progress in clinical and biological research, UNITED
STATES},
Volume = {40},
Pages = {327-30},
Year = {1980},
ISSN = {0361-7742},
Keywords = {Hemoglobin, Sickle* • Kinetics • Microtubules*
• Protein Binding • Thermodynamics • Tubulin
• metabolism},
Key = {fds113083}
}
@article{fds113079,
Author = {WE Fowler and HP Erickson},
Title = {Trinodular structure of fibrinogen. Confirmation by both
shadowing and negative stain electron microscopy.},
Journal = {Journal of molecular biology},
Volume = {134},
Number = {2},
Pages = {241-9},
Year = {1979},
Month = {October},
ISSN = {0022-2836},
Keywords = {Fibrinogen* • Humans • Microscopy, Electron •
Protein Conformation • methods},
Language = {eng},
Key = {fds113079}
}
@article{fds113076,
Author = {WA Voter and HP Erickson},
Title = {Tubulin rings: curved filaments with limited flexibility and
two modes of association.},
Journal = {Journal of supramolecular structure, UNITED
STATES},
Volume = {10},
Number = {4},
Pages = {419-31},
Year = {1979},
ISSN = {0091-7419},
Keywords = {Animals • Macromolecular Substances • Microscopy,
Electron • Microtubules • Protein Conformation
• Tubulin* • ultrastructure*},
Abstract = {Tubulin rings have been previously identified as composed of
linear polymers of tubulin subunits, equivalent to a
protofilament in the microtubule wall but in a curved rather
than a straight conformation. We have examined and measured
a number of different ring structures obtained under
different conditions. The preferred curvature is indicated
by a single ring of 380 A outside diameter. Radially double
rings consist of two coplanar rings of 460 A and 350 A
outside diameter, held together by a pattern of eight
identical contacts between the 40 A subunits in the inner
and outer rings. In some circumstances a larger ring, 570 A
diameter, can be added to the outside, or a smaller ring,
240 A diameter, may be added to the inside of the radially
double ring, in both cases repeating the pattern of eight
radial contacts. The distortion of the filament from its
relaxed 380 A diameter curvature apparently can be made
without disrupting the longitudinal bond between subunits in
the filament, but must be stabilized by the energy of the
radial contact. All of these rings (single and radially
double and triple) are observed to associate axially to form
pairs or in some cases larger stacks. The radially double
rings or an axially associated pair of these (quadruple
ring) may also associate to form crystals. These are thin
plates, up to 100 micrometers in extent and several
micrometers thick which have been of limited use so far in
diffraction studies because of irregularities in the packing
of adjacent rings.},
Key = {fds113076}
}
@article{fds113074,
Author = {HP Erickson and WA Voter and K Leonard},
Title = {Image reconstruction in electron microscopy: enhancement of
periodic structure by optical filtering.},
Journal = {Methods in enzymology, UNITED STATES},
Volume = {49},
Pages = {39-63},
Year = {1978},
ISSN = {0076-6879},
Keywords = {Microscopy, Electron • Protein Conformation* •
instrumentation • methods*},
Key = {fds113074}
}
@article{fds113109,
Author = {T David-Pfeuty and HP Erickson and D Pantaloni},
Title = {Guanosinetriphosphatase activity of tubulin associated with
microtubule assembly.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America, UNITED STATES},
Volume = {74},
Number = {12},
Pages = {5372-6},
Year = {1977},
Month = {December},
ISSN = {0027-8424},
Keywords = {Animals • Brain • Chromatography, Ion Exchange
• Colchicine • GTP Phosphohydrolases •
Glycoproteins • Guanosine Triphosphate • Kinetics
• Microtubules • Phosphoric Monoester Hydrolases
• Swine • Tubulin • Vinblastine •
enzymology • enzymology* • isolation &
purification • metabolism • metabolism* •
pharmacology},
Abstract = {Tubulin, purified by cycles of assembly followed by
phosphocellulose chromatography, exhibits a characteristic
GTPase activity that is polymerization dependent and can be
attributed to the tubulin itself. This activity has been
observed, in a standard reassembly buffer containing low
Mg2+, under three conditions that induce microtubule
assembly: in the presence of microtubule-associated
proteins, in the presence of DEAE-dextran, or after addition
of high Mg2+ and glycerol. The phosphocellulose-purified
tubulin showed no GTPase activity under the following
nonpolymerizing conditions: in buffer with low Mg2+ in the
absence of microtubule-associated proteins or DEAE-dextran,
in buffer with high Mg2+ and glycerol at tubulin
concentrations below the critical concentration, or when
microtubule assembly was inhibited by vinblastine.
Colchicine, on the other hand, while blocking microtubule
assembly, induced a significant GTPase activity in the
phosphocellulose-purified tubulin. During the process of
assembly, GTP appears to be hydrolyzed as a free tubulin
dimer polymerizes into a microtubule. A constant GTPase
activity when polymerization equilibrium is reached
apparently reflects the cyclic polymerization-depolymerization
of tubulin dimers at the ends of the microtubules.},
Key = {fds113109}
}
@article{fds113160,
Author = {HP Erickson and WA Voter},
Title = {Polycation-induced assembly of purified tubulin.},
Journal = {Proceedings of the National Academy of Sciences of the
United States of America, UNITED STATES},
Volume = {73},
Number = {8},
Pages = {2813-7},
Year = {1976},
Month = {August},
ISSN = {0027-8424},
Keywords = {Calcium • Cations, Divalent • Colchicine •
Cold • DEAE-Dextran • Dextrans •
Glycoproteins • Guanosine Triphosphate •
Microtubules* • Tubulin • analogs & derivatives*
• metabolism* • pharmacology • pharmacology*
• ultrastructure},
Abstract = {Several different polycations have been found that can
substitute for the microtubule-associated proteins, or tau
factor, in facilitating assembly of tubulin that has been
purified by ion exchange chromatography. In low
concentrations of the polycation diethylaminoethyl-dextran,
7 mg of tubulin is pelleted per 1 mg of polycation added.
Under conditions favorable to microtubule assembly the
entire pellet is seen by electron microscopy to consist of
"double wall microtubules", which are essentially identical
to normal microtubules in subunit structure and arrangement.
When assembly is inhibited approximately the same amount of
tubulin is pelleted, but it is in the form of clusters of
curved sheets or filaments apparently related to tubulin
rings. When conditions are changed to favor assembly, the
tubulin within these clusters appears to reassemble to form
the double wall microtubules.},
Key = {fds113160}
}
@article{fds113084,
Author = {HP Erickson},
Title = {The structure and assembly of microtubules.},
Journal = {Annals of the New York Academy of Sciences, UNITED
STATES},
Volume = {253},
Pages = {60-77},
Year = {1975},
Month = {June},
ISSN = {0077-8923},
Keywords = {Chromatography, Gel • Computers • Glycerol •
Guanosine Triphosphate • Macromolecular Substances
• Microscopy, Electron • Microtubules •
Models, Structural • Temperature • Tubulin •
X-Ray Diffraction • isolation & purification •
metabolism • ultrastructure*},
Key = {fds113084}
}
@article{fds113125,
Author = {HP Erickson},
Title = {Negatively stained vinblastine aggregates.},
Journal = {Annals of the New York Academy of Sciences, UNITED
STATES},
Volume = {253},
Pages = {51-2},
Year = {1975},
Month = {June},
ISSN = {0077-8923},
Keywords = {Crystallization • Macromolecular Substances •
Microscopy, Electron • Nerve Tissue Proteins* •
Protein Conformation • Tubulin* •
Vinblastine*},
Key = {fds113125}
}
@article{fds113210,
Author = {HP Erickson},
Title = {Microtubule surface lattice and subunit structure and
observations on reassembly.},
Journal = {The Journal of cell biology},
Volume = {60},
Number = {1},
Pages = {153-67},
Year = {1974},
Month = {January},
ISSN = {0021-9525},
Keywords = {Animals • Brain • Brain Chemistry • Computers
• Electrophoresis, Polyacrylamide Gel • Fourier
Analysis • Microscopy, Electron • Microtubules*
• Molecular Conformation • Nerve Tissue Proteins
• Neurons • Protein Conformation • Swine
• analysis • cytology • cytology*},
Abstract = {Neuronal microtubules have been reassembled from brain
tissue homogenates and purified. In reassembly from purified
preparations, one of the first structures formed was a flat
sheet, consisting of up to 13 longitudinal filaments, which
was identified as an incomplete microtubule wall. Electron
micrographs of these flat sheets and intact microtubules
were analyzed by optical diffraction, and the surface
lattice on which the subunits are arranged was determined to
be a 13 filament, 3-start helix. A similar, and probably
identical, lattice was found for outer-doublet microtubules.
Finally, a 2-D image of the structure and arrangement of the
microtubule subunits was obtained by processing selected
images with a computer filtering and averaging system. The
40 x 50 A morphological subunit, which has previously been
seen only as a globular particle and identified as the
55,000-dalton tubulin monomer, is seen in this higher
resolution reconstructed image to be elongated, and split
symmetrically by a longitudinal cleft into two
lobes.},
Language = {eng},
Key = {fds113210}
}
@article{fds113130,
Author = {HP Erickson},
Title = {Assembly of microtubules from preformed, ring-shaped
protofilaments and 6-S tubulin.},
Journal = {Journal of supramolecular structure, UNITED
STATES},
Volume = {2},
Number = {2-4},
Pages = {393-411},
Year = {1974},
ISSN = {0091-7419},
Keywords = {Animals • Brain • Chromatography, Gel •
Computers • Drug Stability • Electrophoresis,
Polyacrylamide Gel • Macromolecular Substances •
Microscopy, Electron • Microtubules • Molecular
Weight • Nerve Tissue Proteins • Protein
Conformation • Spectrophotometry, Ultraviolet •
Swine • X-Ray Diffraction • metabolism •
metabolism* • physiology* • ultrastructure},
Key = {fds113130}
}
%% Papers Published
@article{8954885,
Author = {Erickson, H.P. and White, G.E.},
Title = {Sequence divergence of coiled coils-structural rods, myosin
filament packing, and the extraordinary conservation of
cohesins},
Journal = {J. Struct. Biol. (USA)},
Volume = {154},
Number = {2},
Pages = {111 - 21},
Year = {2006},
url = {http://dx.doi.org/10.1016/j.jsb.2006.01.001},
Keywords = {biochemistry;cellular biophysics;evolution
(biological);molecular biophysics;muscle;proteins;},
Abstract = {The amino acid sequences of the long, anti-parallel coiled
coils of the cohesin subunits SMC1 and SMC3 are almost
totally conserved in mammals. To understand this exceptional
conservation more broadly, we analyzed amino acid sequence
variation for several groups of coiled-coil proteins. Some
long coiled coils, including giantin, NuMA, and Ndc80p/Nuf2p
diverge ~20% from humans to rodents, suggesting they
function as spacer rods, whose sequence divergence is
constrained only by the need to maintain the coiled-coil
structure. Other coiled coils such as skeletal muscle
myosin, intermediate filaments, and the lamins diverge only
1-3%. We suggest that this sequence divergence is
constrained by the extensive packing contacts over the
entire surface of the coiled-coil. The coiled coils of
SMC5/6 and SMC2/4 (condensin) are slightly more constrained
than the presumed spacer rods, diverging 10-15%. Conversely,
the coiled coils of SMC1/3 (cohesin) diverge only 0.0-1.0%.
This extreme constraint suggests that the entire surface of
the coiled coil is intimately involved in the mechanism of
sister chromatid cohesion. Direct binding of the coiled
coils to chromatin, or perhaps the need to avoid such
binding, are two possible mechanisms. Finally, analysis of
the heptad repeat shows that the <i>a</i> and <i>d</i>
positions are more constrained in spacer rods, and the
<i>bcefg</i> positions more constrained in skeletal muscle
myosin. [All rights reserved Elsevier]},
Key = {8954885}
}
@article{05269174334,
Author = {Chen, Yaodong and Erickson, Harold P.},
Title = {Rapid in vitro assembly dynamics and subunit turnover of
FtsZ demonstrated by fluorescence resonance energy
transfer},
Journal = {Journal of Biological Chemistry},
Volume = {280},
Number = {23},
Pages = {22549 - 22554},
Year = {2005},
url = {http://dx.doi.org/10.1074/jbc.M500895200},
Keywords = {Fluorescence;Energy transfer;Monomers;Chemical
activation;Metabolism;Metabolites;Hydrolysis;},
Abstract = {We have developed an assay for the assembly of FtsZ based on
fluorescence resonance energy transfer (FRET). We mutated an
innocuous surface residue to cysteine and labeled separate
pools with fluorescein (donor) and tetramethylrhodamine
(acceptor). When the pools were mixed and GTP was added,
assembly produced a FRET signal that was linearly
proportional to FtsZ concentration from 0.7 μM (the
critical concentration (C<sub>c</sub>)) to 3 μM. At
concentrations greater than 3 μM, an enhanced FRET signal
was observed with both GTP and GDP, indicating additional
assembly above this second C<sub>c</sub>. This second
C<sub>c</sub> varied with Mg<sup>2+</sup> concentration,
whereas the 0.7 μM C<sub>c</sub> did not. We used the
FRET assay to measure the kinetics of initial assembly by
stopped flow. The data were fit by the simple kinetic model
used previously: monomer activation, a weak dimer nucleus,
and elongation, although with some differences in kinetic
parameters from the L68W mutant. We then studied the rate of
turnover at steady state by pre-assembling separate pools of
donor and acceptor protofilaments. When the pools were
mixed, a FRET signal developed with a half-time of 7 s,
demonstrating a rapid and continuous disassembly and
reassembly of protofilaments at steady state. This is
comparable with the 9-s half-time for FtsZ turnover in vivo
and the 8-s turnover time of GTP hydrolysis in vitro.
Finally, we found that an excess of GDP caused disassembly
of protofilaments with a half-time of 5 s. Our new data
suggest that GDP does not exchange into intact
protofilaments. Rather, our interpretation is that subunits
are released following GTP hydrolysis, and then they
exchange GDP for GTP and reassemble into new protofilaments,
all on a time scale of 7 s. The mechanism may be related to
the dynamic instability of microtubules. © 2005 by The
American Society for Biochemistry and Molecular Biology,
Inc.},
Key = {05269174334}
}
@article{05499530249,
Author = {Ohashi, Tomoo and Erickson, Harold P.},
Title = {Domain unfolding plays a role in superfibronectin
formation},
Journal = {Journal of Biological Chemistry},
Volume = {280},
Number = {47},
Pages = {39143 - 39151},
Year = {2005},
url = {http://dx.doi.org/10.1074/jbc.M509082200},
Keywords = {Monomers;Molecules;Precipitation (chemical);Chemical
bonds;Biochemistry;},
Abstract = {Superfibronectin (sFN) is a fibronectin (FN) aggregate that
is formed by mixing FN with anastellin, a fragment of the
first type III domain of FN. However, the mechanism of this
aggregation has not been clear. In this study, we found that
anastellin co-precipitated with FN in a ratio of ~ [similar
to] :1, anastellin: FN monomer. The primary binding site for
anastellin was in the segment <sup>III</sup>1-S, which bound
three molecules of anastellin and was able to form a
precipitate without the rest of the FN molecule. Anastellin
binding to I<sup>II</sup>3 caused a conformational change in
that domain that exposed a cryptic thermolysin-sensitive
site. An additional anastellin binds to <sup>III</sup>11,
where it enhances thermolysin digestion of <sup>III</sup>11.
An engineered disulfide bond in <sup>III</sup>3 inhibited
both aggregation and protease digestion, suggesting that the
stability of <sup>III</sup>S is a key factor in sFN
formation. We propose a three-step model for sFN formation:
1) FN-III domains spontaneously unfold and refold; 2)
anastellin binds to an unfolded domain, preventing its
refolding and leaving it with exposed hydrophobic surfaces
and β-sheet edges; and 3) these exposed elements bind
to similar exposed elements on other molecules, leading to
aggregation. The model is consistent with our observation
that the kinetics of aggregation are first order, with a
reaction time of 500-700 s. Similar mechanisms may
contribute to the assembly of the native FN matrix. ©
2005 by The American Society for Biochemistry and Molecular
Biology, Inc.},
Key = {05499530249}
}
@article{8438406,
Author = {Yaodong Chen and Bjornson, K. and Redick, S.D. and Erickson,
H.P.},
Title = {A rapid fluorescence assay for FtsZ assembly indicates
cooperative assembly with a dimer nucleus},
Journal = {Biophys. J. (USA)},
Volume = {88},
Number = {1},
Pages = {505 - 14},
Year = {2005},
url = {http://dx.doi.org/10.1529/biophysj.104.044149},
Keywords = {cellular biophysics;fluorescence;molecular
biophysics;proteins;thermodynamics;},
Abstract = {FtsZ is the major cytoskeletal protein operating in
bacterial cell division. FtsZ assembles into protofilaments
in vitro, and there has been some controversy over whether
the assembly is isodesmic or cooperative. Assembly has been
assayed previously by sedimentation and light scattering.
However, these techniques will under-report small polymers.
We have now produced a mutant of Escherichia coli FtsZ,
L68W, which gives a 250% increase in tryptophan fluorescence
upon polymerization. This provides a real-time assay of
polymer that is directly proportional to the concentration
of subunit interfaces. FtsZ-L68W is functional for cell
division, and should therefore be a valid model for studying
the thermodynamics and kinetics of FtsZ assembly. We assayed
assembly at pH 7.7 and pH 6.5, in 2.5 mM EDTA. EDTA blocks
GTP hydrolysis and should give an assembly reaction that is
not complicated by the irreversible hydrolysis step.
Assembly kinetics was determined with a stopped-flow device
for a range of FtsZ concentrations. When assembly was
initiated by adding 0.2 mM GTP, fluorescence increase showed
a lag, followed by nucleation, elongation, and a plateau.
The assembly curves were fit to a cooperative mechanism that
included a monomer activation step, a weak dimer nucleus,
and elongation. Fragmentation was absent in the model,
another characteristic of cooperative assembly. The enigma
of how the FtsZ protofilament, which appears to be
one-subunit thick, assemble with apparent cooperativity is
left to us},
Key = {8438406}
}
@article{04308279333,
Author = {Ingham, Kenneth C. and Brew, Shelesa A. and Erickson, Harold
P.},
Title = {Localization of a cryptic binding site for tenascin on
fibronectin},
Journal = {Journal of Biological Chemistry},
Volume = {279},
Number = {27},
Pages = {28132 - 28135},
Year = {2004},
url = {http://dx.doi.org/10.1074/jbc.M312785200},
Keywords = {Cells;Cell culture;Surface plasmon resonance;Dissociation;},
Abstract = {Fibronectin and tenascin are large extracellular matrix
proteins that interact with each other and with integrin
receptors to regulate cell growth and movement. They are
both modular proteins composed of independently folded
domains (modules) that are arranged in linear fashion.
Fibronectin is a covalent dimer and tenascin is a hexamer.
The site on tenascin to which fibronectin binds has been
localized to type III modules 3-5. In this study we use
surface plasmon resonance to examine the interaction between
various fragments of fibronectin and tenascin to further
characterize and localize the binding sites. We found that
tenascin fragments that contain type III modules 3-5 bind
primarily to the N-terminal 29-kDa hep-1/fib-1 domain, which
contains the first five type I modules of fibronectin. The
dissociation constant, K<sub>d</sub>, is approximately
equals 1 μM. The binding site on fibronectin appears to
be cryptic in the whole molecule in solution but is exposed
on the proteolytic fragments and probably when fibronectin
is in the extended conformation.},
Key = {04308279333}
}
@article{04108050476,
Author = {Ohashi, Tomoo and Erickson, Harold P.},
Title = {The Disulfide Bonding Pattern in Ficolin
Multimers},
Journal = {Journal of Biological Chemistry},
Volume = {279},
Number = {8},
Pages = {6534 - 6539},
Year = {2004},
url = {http://dx.doi.org/10.1074/jbc.M310555200},
Keywords = {Chemical beam epitaxy;Collagen;Mutagenesis;Amino
acids;Cells;Chromatography;Molecular structure;},
Abstract = {Ficolin is a plasma lectin, consisting of a short N-terminal
multimerization domain, a middle collagen domain, and a
C-terminal fibrinogen-Hke domain. The collagen domains
assemble the subunits into trimers, and the N-terminal
domain assembles four trimers into 12-mers. Two cysteine
residues in the N-terminal domain are thought to mediate
multimerization by disulfide bonding. We have generated
three mutants of ficolin α in which the N-terminal
cysteines were substituted by serines (Cys<sup>4</sup>, Cys
<sup>24</sup>, and Cys<sup>4</sup>/Cys<sup>24</sup>). The
N-terminal cysteine mutants were produced in a mammalian
cell expression system, purified by affinity chromatography,
and analyzed under nondenaturing conditions to resolve the
multimer structure of the native protein and under
denaturing conditions to resolve the disulfide-linked
structure. Glycerol gradient sedimentation and electron
microscopy in nondenaturing conditions showed that plasma
and recombinant wild-type protein formed 12-mers. The
Cys<sup>4</sup> mutant also formed 12-mers, but
Cys<sup>24</sup> and Cys<sup>4</sup>/Cys<sup>24</sup>
mutants formed only trimers. This means that protein
interfaces containing Cys<sup>4</sup> are stable as
noncovalent protein-protein interactions and do not require
disulfides, whereas those containing Cys<sup>24</sup>-Cys
<sup>24</sup> require the disulfides for stability. Proteins
were also analyzed by nonreducing SDS-PAGE to show the
covalent structure under denaturing conditions. Wild-type
ficolin was covalently linked into 12-mers, whereas
elimination of either Cys<sup>4</sup> or Cys<sup>24</sup>
gave dimers and monomers. We present a model in which
symmetric Cys<sup>24</sup>-Cys <sup>24</sup> disulfide bonds
between trimers are the basis for multimerization. The model
may also be relevant to collectin multimers.},
Key = {04108050476}
}
@article{03297546080,
Author = {Caplan, Michael R. and Erickson, Harold P.},
Title = {Apparent cooperative assembly of the bacterial cell division
protein FtsZ demonstrated by isothermal titration
calorimetry},
Journal = {Journal of Biological Chemistry},
Volume = {278},
Number = {16},
Pages = {13784 - 13788},
Year = {2003},
url = {http://dx.doi.org/10.1074/jbc.M300860200},
Keywords = {Bacteria;Cells;Cytology;Growth kinetics;Oligomers;Electron
microscopy;},
Abstract = {The assembly dynamics of FtsZ, a prokaryotic homolog of
tubulin, are important for their role in bacterial
cytokinesis. Here we used isothermal titration calorimetry
(ITC) to measure the heat of FtsZ self-association under
various conditions. The measurements were designed to test
whether FtsZ protofilaments are assembled by an isodesmic
(linear aggregates in which each bond has an identical
equilibrium constant) or a cooperative (aggregates only
become stable after forming a oligomeric nucleus) assembly
process. The isodesmic model can fit the assembly in GDP
closely but cannot fit the assembly in GTP. FtsZ-GTP without
Mg<sup>2+</sup> exhibits an apparent critical concentration,
which is indicative of cooperative assembly, near 2.9 μM.
With 2.5 mM Mg<sup>2+</sup> (which allows FtsZ to hydrolyze
GTP) the critical concentration is reduced 10-fold to
[similar to] 0.31 μM. Both with and without
Mg<sup>2+</sup> there is no evidence for assembly below the
critical concentration, but there is an abrupt transition to
full assembly above. The ITC data are highly suggestive of a
cooperative assembly, although this is difficult to
reconcile with the 1-subunit-thick protofilaments observed
by electron microscopy.},
Key = {03297546080}
}
@article{7680423,
Author = {Feiya Li and Redick, S.D. and Erickson, H.P. and Moy,
V.T.},
Title = {Force measurements of the α5β1
integrin-fibronectin interaction},
Journal = {Biophys. J. (USA)},
Volume = {84},
Number = {2},
Pages = {1252 - 62},
Year = {2003},
Keywords = {atomic force microscopy;biological techniques;biomechanics;biomolecular
effects of radiation;bonds (chemical);genetics;},
Abstract = {The interaction of the asp, integrin and its ligand,
fibronectin (FN), plays a crucial role in the adhesion of
cells to the extracellular matrix. An important intrinsic
property of the α<sub>5</sub>β<sub>1</sub>/FN
interaction is the dynamic response of the complex to a
pulling force. We have carried out atomic force microscopy
measurements of the interaction between α<sub>5</sub>β<sub>1</sub>
and a fibronectin fragment derived from the seventh through
tenth type III repeats of FN (i.e., FN7-10) containing both
the arg-gly-asp (RGD) sequence and the synergy site. Direct
force measurements obtained from an experimental system
consisting of an α<sub>5</sub>β<sub>1</sub>
expressing K562 cell attached to the atomic force microscopy
cantilever and FN7-10 adsorbed on a substrate were used to
determine the dynamic response of the α<sub>5</sub>β<sub>1</sub>/FN7-10
complex to a pulling force. The experiments were carried out
over a three-orders-of-magnitude change in loading rate and
under conditions that allowed for detection of individual
α<sub>5</sub>β<sub>1</sub>/FN7-10 interactions.
The dynamic rupture force of the α<sub>5</sub>β<sub>1</sub>/FN7-10
complex revealed two regimes of loading: a fast loading
regime (>10,000 pN/s) and a slow loading regime
(<10,000 pN/s) that characterize the inner and outer
activation barriers of the complex, respectively. Activation
by TS2/16 antibody increased both the frequency of adhesion
and elevated the rupture force of the α<sub>5</sub>β<sub>1</sub>/wild
type FN7-10 complex to higher values in the slow loading
regime. In experiments carried out with a FN7-10 RGD deleted
mutant, the force measurements revealed that both inner and
outer activation barriers were suppressed by the mutation.
Mutations to the synergy site of FN, however, suppressed
only the outer barrier activation of the complex. For both
the RGD and synergy deletions, the frequency of adhesion was
less than that of the wild type FN7-10, but was increased by
integrin activation. The rupture force of these mutants was
only slightly less than that of the wild type, and was not
increased by activation. These results suggest that integrin
activation involved a cooperative interaction with both the
RGD and synergy sites},
Key = {7680423}
}
@article{02327048747,
Author = {Ghert, Michelle A. and Qi, Wen-Ning and Erickson, Harold P. and Block, Joel A. and Scully, Sean P.},
Title = {Tenascin-C expression and distribution in cultured human
chondrocytes and chondrosarcoma cells},
Journal = {Journal of Orthopaedic Research},
Volume = {20},
Number = {4},
Pages = {834 - 841},
Year = {2002},
url = {http://dx.doi.org/10.1016/S0736-0266(01)00172-3},
Keywords = {Cells;Oligomers;Cartilage;},
Abstract = {Tenascin-C (TNC) is an oligomeric glycoprotein of the
extracellular matrix with several distinct isoforms variably
expressed during embryogenesis, tumorogenesis, angiogenesis
and wound healing. In the normal human adult, TNC is found
in large concentrations in articular cartilage, suggesting
tissue-specific function. The purpose of this study was to
determine the specific in vitro TNC splicing patterns of
articular chondrocytes and a human chondrosarcoma cell line.
Cells were cultured in a three-dimensional bead system and
TNC splice variant expression and distribution were examined
with the use of Western blotting techniques,
semi-quantitative reverse-transcription polymerase chain
reaction and immunohistochemistry. At both the
transcriptional and post-translational levels, the
chondrocytes were found to express significantly higher
levels of the smaller 220 kDa isoform (P less than or equal
0.01), which was predominantly incorporated into the matrix.
The splicing pattern of the malignant cells was
characterized by a higher proportion of the larger 320 kDa
isoform which was extruded into the media. In vivo studies
are necessary to verify the expression of the large TNC
isoform in chondrosarcoma and the production and integration
of the smaller isoform in normal chondroid matrix. In
addition, elucidation of the biologic functions of the two
major TNC isoforms may lead to the development of novel
diagnostic and therapeutic approaches to chondrosarcoma.
© 2002 Orthopaedic Research Society. Published by
Elsevier Science Ltd. All rights reserved.},
Key = {02327048747}
}
@article{02156912536,
Author = {Takagi, Junichi and DeBottis, Daniel P. and Erickson, Harold
P. and Springer, Timothy A.},
Title = {The role of the specificity-determining loop of the integrin
β subunit I-like domain in autonomous expression,
association with the α subunit, and ligand
binding},
Journal = {Biochemistry},
Volume = {41},
Number = {13},
Pages = {4339 - 4347},
Year = {2002},
url = {http://dx.doi.org/10.1021/bi016047u},
Keywords = {Cells;Mutagenesis;Dimers;Antibodies;Electron
microscopy;},
Abstract = {Integrin β subunits contain a highly conserved I-like
domain that is known to be important for ligand binding.
Unlike integrin I domains, the I-like domain requires
integrin α and β subunit association for optimal
folding. Pactolus is a novel gene product that is highly
homologous to integrin β subunits but lacks associating
α subunits [Chen, Y., Garrison, S., Weis, J. J., and
Weis, J. H. (1998) J. Biol. Chem. 273, 8711-8718] and a
[similar to] 30 amino acid segment corresponding to the
specificity-determining loop (SDL) in the I-like domain. We
find that the SDL is responsible for the defects in integrin
β subunit expression and folding in the absence of
α subunits. When transfected in the absence of α
subunits into cells, extracellular domains of mutant β
subunits lacking SDL, but not wild-type β subunits,
were well secreted and contained immunoreactive I-like
domains. The purified recombinant soluble β1 subunit
with the SDL deletion showed an elongated shape in electron
microscopy, consistent with its structure in αβ
complexes. The SDL segment is not required for formation of
α5β1, α4β1, αVβ3, and
α6β4 heterodimers, but is essential for fomation
of α6β1, αVβ1, and αLβ2
heterodimers, suggesting that usage of subunit interface
residues is variable among integrins. The β1 SDL is
required for ligand binding and for the formation of the
epitope for the α5 monoclonal antibody 16 that maps to
loop segments connecting blades 2 and 3 of β-propeller
domain of α5, but is not essential for nearby
β-propeller epitopes.},
Key = {02156912536}
}
@article{03477736065,
Author = {Anderson, David E. and Trujillo, Kelly M. and Sung, Patrick and Erickson, Harold P.},
Title = {Structure of the Rad50·Mre11 DNA Repair Complex from
Saccharomyces cerevisiae by Electron Microscopy},
Journal = {Journal of Biological Chemistry},
Volume = {276},
Number = {40},
Pages = {37027 - 37033},
Year = {2001},
url = {http://dx.doi.org/10.1074/jbc.M106179200},
Keywords = {Complexation;Genes;Growth kinetics;Proteins;Dimers;Adenosinetriphosphate;},
Abstract = {The RAD50 gene of Saccharomyces cerevisiae is one of several
genes required for recombinational repair of double-strand
DNA breaks during vegetative growth and for initiation of
meiotic recombination. Rad50 forms a complex with two other
proteins, Mre11 and Xrs2, and this complex is involved in
double-strand break formation and processing. Rad50 has
limited sequence homology to the structural maintenance of
chromosomes (SMC) family of proteins and shares the same
domain structure as SMCs: N- and C-terminal globular domains
separated by two long coiled-coils. However, a notable
difference is the much smaller non-coil hinge region between
the two coiled-coils. We report here a structural analysis
of full-length S. cerevisiae Rad50, alone and in a complex
with yeast Mre11 by electron microscopy. Our results confirm
that yeast Rad50 does have the same antiparallel coiled-coil
structure as SMC proteins, but with no detectable globular
hinge domain. However, the molecule is still able to bend
sharply in the middle to bring the two catalytic domains
together, indicating that the small hinge domain is
flexible. We also demonstrate that Mre11 binds as a dimer
between the catalytic domains of Rad50, bringing the
nuclease activities of Mre11 in close proximity to the
ATPase and DNA binding activities of Rad50.},
Key = {03477736065}
}
@article{01436694200,
Author = {Erickson, H.P.},
Title = {Evolution in bacteria},
Journal = {Nature},
Volume = {413},
Number = {6851},
Pages = {30 -},
Year = {2001},
url = {http://dx.doi.org/10.1038/35092655},
Keywords = {Yeast;Cells;Proteins;},
Abstract = {Actin is a major component of the cytoskeleton in yeast,
plant and animal cells, but when did it evolve? The
discovery of a bacterial protein that forms actin-like
filaments suggests an answer.},
Key = {01436694200}
}
@article{03477737280,
Author = {Romberg, Laura and Simon, Martha and Erickson, Harold
p.},
Title = {Polymerization of FtsZ, a bacterial homolog of tubulin. Is
assembly cooperative?},
Journal = {Journal of Biological Chemistry},
Volume = {276},
Number = {15},
Pages = {11743 - 11753},
Year = {2001},
url = {http://dx.doi.org/10.1074/jbc.M009033200},
Keywords = {Polymerization;Nucleation;Concentration (process);Hydrolysis;Chemical
bonds;},
Abstract = {FtsZ is a bacterial homolog of tubulin that is essential for
prokaryotic cytokinesis. In vitro, GTP induces FtsZ to
assemble into straight, 5-nm-wide polymers. Here we show
that the polymerization of these FtsZ filaments most closely
resembles noncooperative (or "isodesmic") assembly; the
polymers are single-stranded and assemble with no evidence
of a nucleation phase and without a critical concentration.
We have developed a model for the isodesmic polymerization
that includes GTP hydrolysis in the scheme. The model can
account for the lengths of the FtsZ polymers and their
maximum steady state nucleotide hydrolysis rates. It
predicts that unlike microtubules, FtsZ protofilaments
consist of GTP-bound FtsZ subunits that hydrolyze their
nucleotide only slowly and are connected by high affinity
longitudinal bonds with a nanomolar KD.},
Key = {03477737280}
}
@article{00075232294,
Author = {Yokoyama, Kenji and Erickson, Harold P. and Ikeda, Yasuo and Takada, Yoshikazu},
Title = {Identification of amino acid sequences in fibrinogen
γ-chain and tenascin C C-terminal domains critical for
binding to integrin αvβ3},
Journal = {Journal of Biological Chemistry},
Volume = {275},
Number = {22},
Pages = {16891 - 16898},
Year = {2000},
url = {http://dx.doi.org/10.1074/jbc.M000610200},
Abstract = {Integrin α<sub>v</sub>β<sub>3</sub> recognizes
fibrinogen γ, and α<sub>E</sub> chain C-terminal
domains (γ/C and α<sub>E</sub>C) but does not
require the γC dodecapeptide sequence
HHLGGAKQAGDV<sup>400-411</sup> for binding to γC. We
have localized the α<sub>v</sub>β<sub>3</sub>
binding sites in γC using γC-derived synthetic
peptides. We found that two peptides GWTVFQKRLDGSV<sup>190-202</sup>
and GVYYQGGTYSKAS<sup>346-358</sup> block the
α<sub>v</sub>β<sub>3</sub> binding to γC or
α<sub>E</sub>C, block the α<sub>v</sub>β<sub>3</sub>-mediated
clot retraction, and induce the ligand-induced binding site
2 (LIBS2) epitope in α<sub>v</sub>β<sub>3</sub>.
Neither peptide affects fibrinogen binding to
α<sub>IIb</sub>β<sub>3</sub>. Scrambled or
inverted peptides were not effective. These results suggest
that the two γC-derived peptides directly interact
with α<sub>v</sub>β<sub>3</sub> and specifically
block α<sub>v</sub>β<sub>3</sub>-γC or
α<sub>E</sub>C interaction. The two sequences are
located next to each other in the γC crystal
structure, although they are separate in the primary
structure. Asp-199, Ser-201, Gin-350, Thr-353, Lys-356,
Ala-357, and Ser-358 residues are exposed to the surface.
This suggests that the two sequences are part of
α<sub>v</sub>β<sub>3</sub> binding sites in
fibrinogen γ/C domain. We also found that tenascin C
C-terminal fibrinogen-like domain specifically binds to
α<sub>v</sub>β<sub>3</sub>. Notably, a peptide
WYRNCHRVNLMG-RYGDNNHSQGVNWFHWKG from this domain that
includes the sequence corresponding to γ/C
GVYYQGGTYSKAS<sup>346-358</sup> specifically binds to
α<sub>v</sub>β<sub>3</sub>, suggesting that
fibrinogen and tenascin C C-terminal domains interact with
α<sub>v</sub>β<sub>3</sub> in a similar
manner.},
Key = {00075232294}
}
@article{04057931144,
Author = {Fong, Alan M. and Erickson, Harold P. and Zachariah, Jason
P. and Poon, Stephen and Schamberg, Neal J. and Imai, Toshio and Patel, Dhavalkumar D.},
Title = {Ultrastructure and function of the fractalkine mucin domain
in CX3C chemokine domain presentation},
Journal = {Journal of Biological Chemistry},
Volume = {275},
Number = {6},
Pages = {3781 - 3786},
Year = {2000},
url = {http://dx.doi.org/10.1074/jbc.275.6.3781},
Abstract = {Fractalkine (FKN), a CX<sub>3</sub>C chemokine/mucin hybrid
molecule on endothelium, functions as an adhesion molecule
to capture and induce firm adhesion of a subset of
leukocytes in a selectin- and integrin-independent manner.
We hypothesized that the FKN mucin domain may be important
for its function in adhesion, and tested the ability of
secreted alkaline phosphatase (SEAP) fusion proteins
containing the entire extracellular region (FKN-SEAP), the
chemokine domain (CX3C-SEAP), or the mucin domain
(mucin-SEAP) to support firm adhesion under flow. CX3C-SEAP
induced suboptimal firm adhesion of resting peripheral blood
mononuclear cells, compared with FKN-SEAP, and mucin-SEAP
induced no firm adhesion. CX3C-SEAP and FKN-SEAP bound to
CX<sub>3</sub>CR1 with similar affinities. By electron
microscopy, fractalkine was 29 nm in length with a long
stalk (mucin domain), and a globular head (CX<sub>3</sub>C).
To test the function of the mucin domain, a chimeric protein
replacing the mucin domain with a rod-like segment of
E-selectin was constructed. This chimeric protein gave the
same adhesion of peripheral blood mononuclear cells as
intact FKN, both when immobilized on glass and when
expressed on the cell surface. This implies that the
function of the mucin domain is to provide a stalk,
extending the chemokine domain away from the endothelial
cell surface to present it to flowing leukocytes.},
Key = {04057931144}
}
@article{99094782163,
Author = {Johnson, Kamin J. and Sage, Harvey and Briscoe, Gina and Erickson, Harold P.},
Title = {Compact conformation of fibronectin is determined by
intramolecular ionic interactions},
Journal = {Journal of Biological Chemistry},
Volume = {274},
Number = {22},
Pages = {15473 - 15479},
Year = {1999},
url = {http://dx.doi.org/10.1074/jbc.274.22.15473},
Abstract = {Fibronectin exists in a compact or extended conformation,
depending upon environmental pH and salt concentration.
Using recombinant fragments expressed in bacteria and
baculovirus, we determined the domains responsible for
producing fibronectin's compact conformation. Our velocity
and equilibrium sedimentation data show that FN2-14 (a
protein containing FN-III domains 2 through 14) forms dimers
in low salt. Experiments with smaller fragments indicates
that the compact conformation is produced by binding of
FN12-14 of one subunit to FN2-3 of the other subunit in the
dimer. The binding is weakened at higher salt
concentrations, implying an electrostatic interaction.
Furthermore, segment FN7-14+A, which contains the
alternatively spliced A domain between FN11 and 12, forms
dimers, whereas FN7-14 without A does not. Segment FN12-14+A
also forms dimers, but the isolated A domain does not. These
data imply an association of domain A with FN12-14, and the
presence of A may favor an open conformation by competing
with FN2-3 for binding to FN12-14.},
Key = {99094782163}
}
@article{98084317794,
Author = {Lu, C. and Stricker, J. and Erickson, H.
P.},
Title = {FtsZ From Escherichia coli, Azotobacter vinelandii and
Thermotoga maritima - Quantitation, GTP Hydrolysis and
Assembly},
Journal = {Cell Motility and the Cytoskeleton},
Volume = {40},
Number = {1},
Pages = {71 -},
Year = {1998},
url = {http://dx.doi.org/10.1002/(SICI)1097-0169(1998)40:1<71::AID-CM7>3.0.CO;2-I},
Key = {98084317794}
}
@article{5957365,
Author = {Oberhauser, A.F. and Marszalek, P.E. and Erickson, H.P. and Fernandez, J.M.},
Title = {The molecular elasticity of the extracellular matrix protein
tenascin},
Journal = {Nature (UK)},
Volume = {393},
Number = {6681},
Pages = {181 - 5},
Year = {1998},
url = {http://dx.doi.org/10.1038/30270},
Keywords = {biomechanics;cellular biophysics;elasticity;molecular
biophysics;proteins;},
Abstract = {Extracellular matrix proteins are thought to provide a rigid
mechanical anchor that supports and guides migrating and
rolling cells. Here the authors examine the mechanical
properties of the extracellular matrix protein tenascin by
using atomic-force-microscopy techniques. The authors'
results indicate that tenascin is an elastic protein. Single
molecules of tenascin could be stretched to several times
their resting length. Force-extension curves showed a
saw-tooth pattern, with peaks of force at 137 pN. These
peaks were ~25 nm apart. Similar results have been obtained
by study of titin. The authors also found similar results by
studying recombinant tenascin fragments encompassing the 15
fibronectin type III domains of tenascin. This indicates
that the extensibility of tenascin may be due to the
stretch-induced unfolding of its fibronectin type III
domains. Refolding of tenascin after stretching, observed
when the force was reduced to near zero, showed a
double-exponential recovery with time constants of 42
domains refolded per second and 0.5 domains per second. The
former speed of refolding is more than twice as fast as any
previously reported speed of refolding of a fibronectin type
III domain. The authors suggest that the extensibility of
the modular fibronectin type III region may be important in
allowing tenascin-ligand bonds to persist over long
extensions. These properties of fibronectin type III modules
may be of widespread use in extracellular proteins
containing such domain},
Key = {5957365}
}
@article{97065007499,
Author = {Erickson, H.P.},
Title = {Stretching single protein molecules: Titin is a weird
spring},
Journal = {Science},
Volume = {276},
Number = {5315},
Pages = {1090 -},
Year = {1997},
url = {http://dx.doi.org/10.1126/science.276.5315.1090},
Key = {97065007499}
}
@article{97043600400,
Author = {O'Brien, E. T. and Salmon, E. D. and Erickson, H.
P.},
Title = {How Calicum Causes Microtubule Depolymerization},
Journal = {Cell Motility and the Cytoskeleton},
Volume = {36},
Number = {2},
Pages = {125 -},
Year = {1997},
url = {http://dx.doi.org/10.1002/(SICI)1097-0169(1997)36:2<125::AID-CM3>3.0.CO;2-8},
Key = {97043600400}
}
@article{05118953507,
Author = {Chandra, Rashmi and Salmon, Edward D. and Erickson, Harold
P. and Lockhart, Andrew and Endow, Sharyn
A.},
Title = {Structural and functional domains of the Drosophila ncd
microtubule motor protein},
Journal = {Journal of Biological Chemistry},
Volume = {268},
Number = {12},
Pages = {9005 - 9013},
Year = {1993},
Abstract = {Nonclaret disjunctional (ncd) is a kinesin-related
microtubule motor protein that is required for proper
chromosome distribution in Drosophila. Despite its sequence
similarity to kinesin heavy chain, ncd translocates with the
opposite polarity as kinesin, toward microtubule minus ends.
We have expressed different regions of the protein in
bacteria and analyzed the proteins for function. Results
indicate that ncd consists of three domains: a basic,
proline-rich N-terminal "tail," a central α-helical
coiled-coil stalk, and a C-terminal motor domain. The ncd N
terminus proteins bundle microtubules in motility assays and
show ATP-independent binding to microtubules in solution.
Truncated proteins, lacking the tail but containing the
predicted motor domain and differing lengths of the stalk,
did not support microtubule gliding in in vitro assays but
showed microtubule-stimulated MgATPase activity in solution.
Addition of a nonspecific N terminus to two of the truncated
proteins restored directional gliding and rotation of
microtubules in motility assays, demonstrating that these
properties map to the predicted mechanochemical domain of
ncd. Physical properties of the C terminus proteins indicate
that the stalk region is important for dimerization and that
the ncd protein probably exists and functions as a
dimer.},
Key = {05118953507}
}
@article{94011178765,
Author = {Goodsell, D.S. and Erickson, Harold P.},
Title = {Machinery of life},
Journal = {Nature},
Volume = {365},
Number = {6444},
Pages = {306 -},
Year = {1993},
Key = {94011178765}
}
@article{05118954042,
Author = {Ushiyama, Shigeru and Laue, Thomas M. and Moore, Kevin L. and Erickson, Harold P. and McEver, Rodger
P.},
Title = {Structural and functional characterization of monomeric
soluble P-selectin and comparison with membrane
P-selectin},
Journal = {Journal of Biological Chemistry},
Volume = {268},
Number = {20},
Pages = {15229 - 15237},
Year = {1993},
Abstract = {P-selectin is an adhesion receptor for leukocytes on
thrombin-activated platelets and endothelial cells. It
contains a NH<sub>2</sub>-terminal carbohydrate-recognition
domain, an epidermal growth factor motif, nine consensus
repeats, a transmembrane domain, and a cytoplasmic tail. We
expressed two soluble forms of P-selectin, one truncated
after the ninth repeat (tPS) and the other lacking the
transmembrane domain due to alternative RNA splicing (asPS).
When visualized by electron microscopy, each was a monomeric
rod-like structure with a globular domain at one end,
whereas membrane P-selectin (mPS) from platelets formed
rosettes with the globular domains facing outward.
Sedimentation velocity and equilibrium studies confirmed
that tPS and asPS were asymmetric monomers, whereas mPS was
oligomeric. HL-60 cells adhered to immobilized tPS and asPS,
although less efficiently than to mPS. <sup>125</sup>I-Labeled
tPS and asPS bound to -25,000 sites/neutrophil and [similar
to] 36,000 sites/HL-60 cell with an apparent Kd of 70 nM.
Treatment of HL-60 cells with O-sialoglycoprotease
eliminated the binding sites for asPS. We conclude that 1)
P-selectin is a rigid, asymmetric protein; 2) monomeric
soluble P-selectin binds to high affinity ligands with
sialylated O-linked oligosaccharides on leukocytes; and 3)
oligomerization of mPS enhances its avidity for
leukocytes.},
Key = {05118954042}
}
@article{4314419,
Author = {Leahy, D.J. and Hendrickson, W.A. and Aukhil, I. and Erickson, H.P.},
Title = {Structure of a fibronectin type III domain from tenascin
phased by MAD analysis of the selenomethionyl
protein},
Journal = {Science (USA)},
Volume = {258},
Number = {5084},
Pages = {987 - 91},
Year = {1992},
Keywords = {crystal atomic structure of organic compounds;macromolecular
configurations;molecular biophysics;proteins;},
Abstract = {Fibronectin type III domains are found in many different
proteins including cell surface receptors and cell adhesion
molecules. The crystal structure of one such domain from the
extracellular matrix protein tenascin was determined. The
structure was solved by multiwavelength anomalous
diffraction (MAD) phasing of the selenomethionyl protein and
has been refined to 1.8 angstrom resolution. The folding
topology of this domain is identical to that of the
extracellular domains of the human growth hormone receptor,
the second domain of CD4, and PapD. Although distinct, this
topology is similar to that of immunoglobulin constant
domains. An Arg-Gly-Asp (RGD) sequence that can function for
cell adhesion is found in a tight turn on an exposed
loop},
Key = {4314419}
}
@article{05118963866,
Author = {Schaefer, Erik M. and Erickson, Harold P. and Federwisch,
Matthias and Wollmer, Axel and Ellis, Leland},
Title = {Structural organization of the human insulin receptor
ectodomain},
Journal = {Journal of Biological Chemistry},
Volume = {267},
Number = {32},
Pages = {23393 - 23402},
Year = {1992},
Abstract = {To provide an experimental system amenable to a detailed
biochemical and structural investigation of the
extracellular (ligand binding) domain of the insulin
receptor, we developed a mammalian heterologous cell
expression system from which tens of milligrams of the
soluble secreted ectodomain (the IR921 protein) can be
routinely purified using methods that do not require harsh
elution conditions. The purified IR921 protein has a Stokes
radius of 6.8 nm and a sedimentation coefficient of 9.8 S,
from which we calculate a hydrodynamic mass of 281 kDa.
Electron microscopic images, using both rotary shadowing and
negative staining techniques, demonstrate a characteristic
substructure for the IR921 protein consisting of two
elongated arms, with a globular domain at each end,
connected to each other at a point somewhat off-center to
form a Y structure. Analysis using circular dichroism and
fluorescence spectroscopy illustrate that insulin binding
results in conformational changes in the ectodomain.
Furthermore, fluorescence anisotropy decay data reveal
segmental mobility within the IR921 protein that is
successively frozen as a result of insulin binding, in
contrast to results obtained in a previous study of the
epidermal growth factor receptor ectodomain. This result
suggests a divergence in hormone-induced signaling
mechanisms used by the insulin and epidermal growth factor
receptors.},
Key = {05118963866}
}
@article{05118962676,
Author = {LeMosy, Ellen K. and Erickson, Harold P. and Beyer Jr.,
Wayne F. and Radek, James T. and Jeong, Jong-Moon and Murthy, S. N. Prasanna and Lorand, Laszlo},
Title = {Visualization of purified fibronectin-transglutaminase
complexes},
Journal = {Journal of Biological Chemistry},
Volume = {267},
Number = {11},
Pages = {7880 - 7885},
Year = {1992},
Abstract = {It has been reported previously (Turner, P. M., and Lorand,
L. (1989) Biochemistry 28, 628-635) that human erythrocyte
transglutaminase forms a noncovalent complex with human
plasma fibronectin near its collagen-binding domain. In the
present study, we show by nondenaturing electrophoresis that
guinea pig liver transglutaminase, similarly to the
erythrocyte enzyme, forms a complex with human fibronectin.
Studies of anisotropic shifts of fluorescein-labeled liver
and erythrocyte transglutaminases, upon addition of
fibronectin, indicated that both transglutaminases bind to
fibronectin with a stoichiometry of about 2:1.
Polymerization of fibrinogen by human erythryocyte
transglutaminase was inhibited after complex formation with
fibronectin. Complexes of fibronectin with either
erythrocyte or liver transglutaminase were isolated by
glycerol gradient zone sedimentation and examined by rotary
shadowing electron microscopy. The globular transglutaminase
could be readily identified binding to the thin fibronectin
strand. The binding site for transglutaminase was within
5-10 nm of the N terminus of fibronectin, consistent with
its proximity to the collagen-binding domain. Under some
experimental conditions, the complex of fibronectin with
erythrocyte transglutaminase appeared as a ring-shaped
structure in which two transglutaminase molecules had
probably dimerized. The molecular weight of the erythrocyte
transglutaminase was determined by sedimentation equilibrium
to be 71,440 ± 830.},
Key = {05118962676}
}
@article{05118981578,
Author = {Neely, M. Diana and Erickson, Harold P. and Boekelheide,
Kim},
Title = {HMW-2, the Sertoli cell cytoplasmic dynein from rat testis,
is a dimer composed of nearly identical subunits},
Journal = {Journal of Biological Chemistry},
Volume = {265},
Number = {15},
Pages = {8691 - 8698},
Year = {1990},
Abstract = {The ultrastructure and biochemical characteristics of HMW-2,
the Sertoli cell cytoplasmic dynein isolated from rat
testes, were analyzed. Electron microscopic studies revealed
a two-headed two-stem structure with dimensions very similar
to other dyneins. We found that, like other cytoplasmic
dyneins, both heads have an approximately spherical shape
with a central cavity. Heavy chain analysis suggested the
presence of only one type of heavy chain, a finding that was
supported by the simple Michaelis-Menten kinetics displayed
by the HMW-2-associated ATPase activity. In addition,
dissociation of the HMW-2 complex resulted in a single type
of dynein subunit sedimenting at 11.8 S. This fraction
contained all the polypeptides present in the undissociated
HMW-2. Ultrastructurally the HMW-2 subunits were composed of
one globular domain with a tail. The simplest interpretation
is that HMW-2 is a dimer of nearly identical subunits, each
containing one heavy chain, one 90-kDa intermediate chain,
and two light chains.},
Key = {05118981578}
}
@article{1706939,
Author = {Erickson, H.P. and Pantaloni, D.},
Title = {The role of subunit entropy in cooperative assembly.
Nucleation of microtubules and other two-dimensional
polymers},
Journal = {Biophys. J. (USA)},
Volume = {34},
Number = {2},
Pages = {293 - 309},
Year = {1981},
Keywords = {biothermics;entropy of substances;molecular
biophysics;polymers;},
Abstract = {The self-assembly and nucleation of two-dimensional polymers
is described by a theory based on a model of rigid subunits
and bonds and simple principles of thermodynamics. The key
point in the theory is to separate as an explicit parameter
the free energy, primarily attributed to the entropy of the
free subunit, that is required to immobilize a subunit in
the polymer. Quantitative relations for the association of a
subunit forming a longitudinal bond, a lateral bond, or both
together are obtained, which demonstrate the basis and
magnitude of cooperativity. The same formalism leads to a
quantitative estimate for the concentration of the small
polymers that are important intermediates in nucleation. It
is shown that, if the concentration of free subunits is
below a certain `critical supersaturation', the
concentration of some essential intermediates is too low to
support any significant assembly and nucleation is blocked.
If the subunit concentration is above the critical
supersaturation, all of the small intermediates are
sufficiently stable to form and grow spontaneously. The
theory predicts a critical supersaturation of 3.5 to 7 (the
ratio of subunit concentration to the equilibrium
solubility) for parameters appropriate to assembly of the
microtubule wall. Experimentally, nucleation and assembly of
microtubules is obtained at somewhat lower concentrations,
1.5 to 3 times the equilibrium solubility. Special
mechanisms that could stabilize small polymers and
facilitate nucleation of microtubule assembly are
suggested},
Key = {1706939}
}
@article{1728565,
Author = {Fowler, W.E. and Erickson, H.P. and Hantgan, R.R. and McDonagh, J. and Hermans, J.},
Title = {Cross-linked fibrinogen dimers demonstrate a feature of the
molecular packing in fibrin fibers},
Journal = {Science (USA)},
Volume = {211},
Number = {4479},
Pages = {287 - 9},
Year = {1981},
Keywords = {blood;macromolecular configurations;molecular
biophysics;proteins;},
Abstract = {A stable population of fibrinogen dimers cross-linked by
Factor XIIIa has been prepared and examined in the electron
microscope. The trinodular fibrinogen molecules are
cross-linked through their outer nodules in an end-to-end,
non-overlapping fashion. These dimers form normal banded
fibers after treatment with the clotting enzyme,
thrombin},
Key = {1728565}
}
@article{348238,
Author = {Erickson, H.P. and Klug, A.},
Title = {Phase contrast electron microscopy and compensation of
aberrations by Fourier image processing},
Journal = {Proceedings of the 28th annual meeting of the Electron
Microscopy Society of America (condensed
papers)},
Pages = {248 - 9},
Address = {Houston, TX, USA},
Year = {1970},
Keywords = {electron microscopy;Fourier analysis;organic
compounds;},
Abstract = {The authors study the title phenomena by investigating
experimentally the imaging of a specimen of negatively
strained catalase crystals},
Key = {348238}
}
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