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| Publications [#112927] of G Vann V. Bennett
Papers Published
- ZP Li, EP Burke, JS Frank, V Bennett, KD Philipson, The cardiac Na+-Ca2+ exchanger binds to the cytoskeletal protein ankyrin.,
The Journal of biological chemistry, UNITED STATES, vol. 268 no. 16
(June, 1993),
pp. 11489-91, ISSN 0021-9258
(last updated on 2003/02/18)
Abstract:
Na+-Ca2+ exchange is the major pathway of Ca2+ efflux during excitation-contraction coupling in cardiac muscle. The Na+-Ca2+ exchanger is present in cardiac transverse tubules with an apparent high density (Frank, J.S., Mottino, G., Reid, D., Molday, R. S., and Philipson, K.D. (1992) J. Cell Biol. 117, 337-345). The mechanism for this localization is unknown but may involve interactions with the cytoskeleton. In the present study, we examined the interaction of the Na+-Ca2+ exchanger with the cytoskeletal protein ankyrin. On immunoblots of isolated canine cardiac sarcolemma, an antibody raised against purified rabbit red blood cell-ankyrin (RBC-ankyrin) recognized a 220-kDa protein, which is the same size as RBC-ankyrin. Alkaline extraction of sarcolemma removed this protein. The Na+-Ca2+ exchange protein, purified from recombinant baculovirus-infected insect cells, bound 125I-labeled-RBC-ankyrin with a KD of 42 +/- 3 nm. 125I-RBC-ankyrin was co-precipitated by antibodies to the Na+-Ca2+ exchanger after preincubation with solubilized cardiac sarcolemma. Myocardial ankyrin could be localized to both surface and T-tubular sarcolemma by immunofluorescence techniques. These results demonstrate that the cardiac Na+-Ca2+ exchanger binds ankyrin with high affinity. This interaction may be important for localizing the Na+-Ca2+ exchanger to specific domains of the sarcolemma.
Keywords:
Animals • Ankyrins • Carrier Proteins • Cell Line • Dogs • Erythrocytes • Fluorescent Antibody Technique • Kinetics • Moths • Myocardium • Protein Binding • Rabbits • Sarcolemma • Sodium Chloride Symporters • Symporters* • Transfection • analysis • isolation & purification • metabolism • metabolism*
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