The ATP synthase (F1-Fo, H+ATPase) is a multisubunit enzyme that utilizes the energy of the transmembrane H+ electrochemical gradient to drive the thermodynamic unfavorable synthesis of ATP. The molecular mechanisms underlying the transduction of electrochemical into the chemical energy of ATP are unclear at present. The long term objective of the present project is the elucidation of energy transduction mechanisms of ATP synthesis by mitochondrial ATP synthase. The primary focus of the present proposal is to elucidate the structure and function of Oligomycin sensitivity conferring protein (OSCP) and other stalk subunits in order to obtain some insights on their role in energy transduction.
The specific aims i nclude i) identification of domains of OSCP that are of structural and/functional importance, ii) elucidation of a) subunit interactions of OSCP and of b) possible conformational transitions in OSCP in specific response to energization, deenergization and uncoupling of mitochondria. These studies will be carried out using a combination of genetic engineering and physico-biochemical approaches.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM026420-10
Application #
3273901
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1981-04-01
Project End
1995-08-31
Budget Start
1993-09-01
Budget End
1994-08-31
Support Year
10
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Boston Biomedical Research Institute
Department
Type
DUNS #
058893371
City
Watertown
State
MA
Country
United States
Zip Code
02472
Joshi, S; Cao, G J; Nath, C et al. (1997) Oligomycin sensitivity conferring protein (OSCP) of bovine heart mitochondrial ATP synthase: high-affinity OSCP-Fo interactions require a local alpha-helix at the C-terminal end of the subunit. Biochemistry 36:10936-43
Joshi, S; Cao, G J; Nath, C et al. (1996) Oligomycin sensitivity conferring protein of mitochondrial ATP synthase: deletions in the N-terminal end cause defects in interactions with F1, while deletions in the C-terminal end cause defects in interactions with F0. Biochemistry 35:12094-103
Joshi, S; Javed, A A; Gibbs, L C (1992) Oligomycin sensitivity-conferring protein (OSCP) of mitochondrial ATP synthase. The carboxyl-terminal region of OSCP is essential for the reconstitution of oligomycin-sensitive H(+)-ATPase. J Biol Chem 267:12860-7
Joshi, S; Huang, Y G (1991) ATP synthase complex from bovine heart mitochondria: the oligomycin sensitivity conferring protein is essential for dicyclohexyl carbodiimide-sensitive ATPase. Biochim Biophys Acta 1067:255-8
Javed, A A; Joshi, S (1990) Targeted DNA sequencing: rapid identification of DNA clones by sequencing DNA using mixed oligodeoxynucleotide probes as primers. Biotechniques 9:28-32
Joshi, S; Burrows, R (1990) ATP synthase complex from bovine heart mitochondria. Subunit arrangement as revealed by nearest neighbor analysis and susceptibility to trypsin. J Biol Chem 265:14518-25
Pringle, M J; Kenneally, M K; Joshi, S (1990) ATP synthase complex from bovine heart mitochondria. Passive H+ conduction through F0 does not require oligomycin sensitivity-conferring protein. J Biol Chem 265:7632-7
Joshi, S; Pringle, M J (1989) ATP synthase complex from bovine heart mitochondria. Passive H+ conduction through mitochondrial coupling factor 6-depleted F0 complexes. J Biol Chem 264:15548-51
Joshi, S; Pringle, M J; Siber, R (1986) Topology and function of ""stalk"" proteins in the bovine mitochondrial H+-ATPase. J Biol Chem 261:10653-8
Joshi, S; Hughes, J B; Torok, K et al. (1985) Resolution and reconstitution of H+ -ATPase complex from beef heart mitochondria. Membr Biochem 5:309-25

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