The class of proton-pumping ATPases (vacuolar ATPases) found in intracellular acidic vacuoles and in some epithelia (e.g. intercalated cells of kidney). They have up to fourteen protein subunits arranged in a cytoplasmic V1 complex, which mediates the hydrolysis of ATP, and a membrane-embedded V0 complex, which translocates H+ across the membrane. The pump is a molecular motor in which ATP hydrolysis turns a rotor consisting of one copy of subunits D and F of the V1 complex and a ring of six or more copies of subunit C of the V0 complex. The rotation of the ring is thought to deliver H+ from the cytoplasmic to the endosomal or extracellular side of the membrane. V-type ATPases are inhibited by bafilomycin. Compare F-type ATPase; P-type ATPase. Mutation in one of the V0 subunits (ATP6V0A2) causes autosomal recessive cutis laxa type II; mutation in ATP6V1B1 (a V1 complex subunit) causes distal renal tubular acidosis with progressive deafness.
http://jeb.biologists.org/cgi/content/full/209/4/577 Review article in the Journal of Experimental Biology (2006).
Subjects: Medicine and Health.