| First Author | Lu M | Year | 2002 |
| Journal | J Biol Chem | Volume | 277 |
| Issue | 41 | Pages | 38409-15 |
| PubMed ID | 12163484 | Mgi Jnum | J:327411 |
| Mgi Id | MGI:7332754 | Doi | 10.1074/jbc.M203521200 |
| Citation | Lu M, et al. (2002) 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. J Biol Chem 277(41):38409-15 |
| abstractText | 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 F(1)F(0)-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 confirmed in vitro by 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 A(1)-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. |
