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Regulation and reversibility of vacuolar H(+)-ATPase.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2000 Jan 07; Vol. 275 (1), pp. 386-9. - Publication Year :
- 2000
-
Abstract
- Arabidopsis thaliana vacuolar H(+)-translocating pyrophosphatase (V-PPase) was expressed functionally in yeast vacuoles with endogenous vacuolar H(+)-ATPase (V-ATPase), and the regulation and reversibility of V-ATPase were studied using these vacuoles. Analysis of electrochemical proton gradient (DeltamuH) formation with ATP and pyrophosphate indicated that the proton transport by V-ATPase or V-PPase is not regulated strictly by the proton chemical gradient (DeltapH). On the other hand, vacuolar membranes may have a regulatory mechanism for maintaining a constant membrane potential (DeltaPsi). Chimeric vacuolar membranes showed ATP synthesis coupled with DeltamuH established by V-PPase. The ATP synthesis was sensitive to bafilomycin A(1) and exhibited two apparent K(m) values for ADP. These results indicate that V-ATPase is a reversible enzyme. The ATP synthesis was not observed in the presence of nigericin, which dissipates DeltapH but not DeltaPsi, suggesting that DeltapH is essential for ATP synthesis.
- Subjects :
- Anti-Bacterial Agents pharmacology
Arabidopsis enzymology
Biological Transport
Cell Compartmentation
Gene Expression Regulation, Enzymologic
Intracellular Membranes enzymology
Proton-Motive Force
Proton-Translocating ATPases antagonists & inhibitors
Proton-Translocating ATPases genetics
Pyrophosphatases genetics
Recombinant Proteins metabolism
Saccharomyces cerevisiae genetics
Adenosine Triphosphate metabolism
Macrolides
Proton-Translocating ATPases metabolism
Pyrophosphatases metabolism
Vacuolar Proton-Translocating ATPases
Vacuoles enzymology
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 275
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 10617629
- Full Text :
- https://doi.org/10.1074/jbc.275.1.386