Back to Search
Start Over
The Amino-terminal Domain of the E Subunit of Vacuolar H+-ATPase (V-ATPase) Interacts with the H Subunit and Is Required for V-ATPase Function*
- Source :
- Journal of Biological Chemistry; October 2002, Vol. 277 Issue: 41 p38409-38415, 7p
- Publication Year :
- 2002
-
Abstract
- Vacuolar H+-ATPases (V-ATPases) are highly conserved proton pumps that couple hydrolysis of cytosolic ATP to proton transport out of the cytosol. Although it is generally believed that V-ATPases transport protons by a rotary catalytic mechanism analogous to that used by F1F0-ATPases, the structure and subunit composition of the central or peripheral stalk of the multisubunit complex are not well understood. We searched for proteins that bind to the E subunit of V-ATPase using the yeast two-hybrid assay and identified the H subunit as an interacting partner. Physical association between the E and H subunits of V-ATPase was confirmedin vitroby precipitation assays. Deletion mapping analysis revealed that a 78-amino acid fragment at the amino terminus of the E subunit was sufficient for binding to the H subunit. Expression of the amino-terminal fragments of the E subunits from human and yeast as dominant-negative mutants resulted in dramatic decreases in bafilomycin A1-sensitive ATP hydrolysis and proton transport activities of V-ATPase. Our data demonstrate the physiological significance of the interaction between the E and H subunits of V-ATPase and extend previous studies on the arrangement of subunits on the peripheral stalk of V-ATPase.
Details
- Language :
- English
- ISSN :
- 00219258 and 1083351X
- Volume :
- 277
- Issue :
- 41
- Database :
- Supplemental Index
- Journal :
- Journal of Biological Chemistry
- Publication Type :
- Periodical
- Accession number :
- ejs7246945
- Full Text :
- https://doi.org/10.1074/jbc.M203521200