James N. Siedow, Professor Emeritus  

James N. Siedow

Physiological, biochemical and molecular studies of plant oxidative processes.

I suspended the operation of my laboratory about eight years ago.

Historically, the research in my laboratory looked at metabolic processes related to aerobic respiration in plants and fungi. Specifically, this research involves isolating and characterizing the structural and regulatory features of the cyanide-resistant "alternative" oxidase associated with all plant and many fungal mitochondria. The mechanism of action of a regulatory sulfhydryl-disulfide system on the alternative oxidase and its interplay with the activating effects of alpha-keto acids are currently under study, as is the characterization of structural features of the alternative protein and its active site.

Comparative studies of the plant and fungal alternative oxidases have indicated a common structural framework but distinctly different regulatory features. This research involves the application of standard biochemical approaches, including chemical cross-linking, immunochemical technologies, and electrochemical methodologies. These approaches are further complemented by the use of site-directed mutagenesis of the alternative oxidase expressed in both the bacterium E. coli and transgenic Arabidopsis thaliana.

Transformed Arabidopsis having over- and underexpressed wild-type, as well as altered forms of the alternative oxidase lacking normal regulatory control have been developed and are being used to characterize the role played by the alternative oxidase in response to different developmental and environmental circumstances, including extremes of temperature, pathogen infection, and nutrient limitations.

Education:
Ph.D., Indiana University at Indianapolis, 1972
B.A., University of Texas at Austin, 1969

Office Location: 130 Science Drive, 3105 French Science Centre, Durham, NC 27708
Office Phone: (919) 684-5445
Email Address: jim.siedow@duke.edu

Specialties:
Cell and Molecular Biology
Genetics

Research Categories: Function and regulation of plant respiratory pathways

Current projects: Cyanide-resistant respiration and plant stress

Research Description: Physiological, biochemical and molecular studies of plant oxidative processes.

Research in my laboratory studies metabolic processes related to aerobic respiration in plants and fungi. Specifically, this research involves isolating and characterizing the structural and regulatory features of the cyanide-resistant "alternative" oxidase associated with all plant and many fungal mitochondria. The mechanism of action of a regulatory sulfhydryl-disulfide system on the alternative oxidase and its interplay with the activating effects of alpha-keto acids are currently under study, as is the characterization of structural features of the alternative protein and its active site.

Comparative studies of the plant and fungal alternative oxidases have indicated a common structural framework but distinctly different regulatory features. This research involves the application of standard biochemical approaches, including chemical cross-linking, immunochemical technologies, and electrochemical methodologies. These approaches are further complemented by the use of site-directed mutagenesis of the alternative oxidase expressed in both the bacterium E. coli and transgenic Arabidopsis thaliana.

Transformed Arabidopsis having over- and underexpressed wild-type, as well as altered forms of the alternative oxidase lacking normal regulatory control have been developed and are being used to characterize the role played by the alternative oxidase in response to different developmental and environmental circumstances, including extremes of temperature, pathogen infection, and nutrient limitations.

Areas of Interest:
plant respiration
plant bioenergetics
plant stress responses

Recent Publications   (More Publications)   (search)

  1. Yuan, F; Yang, H; Xue, Y; Kong, D; Ye, R; Li, C; Zhang, J; Theprungsirikul, L; Shrift, T; Krichilsky, B; Johnson, DM; Swift, GB; He, Y; Siedow, JN; Pei, ZM, Corrigendum: OSCA1 mediates osmotic-stress-evoked Ca(2+) increases vital for osmosensing in Arabidopsis., Nature (February, 2015) .
  2. Yuan, F; Yang, H; Xue, Y; Kong, D; Ye, R; Li, C; Zhang, J; Theprungsirikul, L; Shrift, T; Krichilsky, B; Johnson, DM; Swift, GB; He, Y; Siedow, JN; Pei, Z-M, OSCA1 mediates osmotic-stress-evoked Ca2+ increases vital for osmosensing in Arabidopsis., Nature, vol. 514 no. 7522 (October, 2014), pp. 367-371 [doi]  [abs].
  3. Wu, X; Wu, F-H; Wang, X; Wang, L; Siedow, JN; Zhang, W; Pei, Z-M, Molecular evolutionary and structural analysis of the cytosolic DNA sensor cGAS and STING., Nucleic Acids Research, vol. 42 no. 13 (July, 2014), pp. 8243-8257 [doi]  [abs].
  4. Florez-Sarasa, I; Flexas, J; Rasmusson, AG; Umbach, AL; Siedow, JN; Ribas-Carbo, M, In vivo cytochrome and alternative pathway respiration in leaves of Arabidopsis thaliana plants with altered alternative oxidase under different light conditions., Plant Cell & Environment, vol. 34 no. 8 (August, 2011), pp. 1373-1383 [21486306], [doi]  [abs].
  5. Moller, IM; Rasmusson, AG; Siedow, JJN; Vanlerberghe, GC, The product of the alternative oxidase is still H2O, Archives of Biochemistry and Biophysics, vol. 495 no. 1 (2010), pp. 93-94 [Gateway.cgi], [doi] .