VMA10 encodes the G subunit of the yeast V-ATPase V₁ domain (1). Vacuolar (H )-ATPases (V-ATPases) are ATP-dependent proton pumps that have been identified in many eukaryotes, where they acidify intracellular vacuolar compartments. Vacuolar acidification is important for many cellular processes, including endocytosis, targeting of newly synthesized lysosomal enzymes, and other molecular targeting processes. The V-ATPase consists of two separable domains. The V₁ domain has eight known subunits, is peripherally associated with the vacuolar membrane, and catalyzes ATP hydrolysis. The V₀ domain is an integral membrane structure of five subunits, and transports protons across the membrane. The structure, function, and assembly of V-ATPases are reviewed in references 2, 3, 4 and 5.

The vma10 null mutant is viable but lacks vacuolar (H )-ATPase activity, cannot grow at neutral pH, and fails to accumulate quinacrine in the vacuole (1). In the absence of Vma10p, the remaining V₁ subunits do not associate with the vacuolar membrane (6). A specific interaction between Vma10p and the V-ATPase E subunit (Vma4p) has been detected (7).

Last updated: 2000-05-16