Part of the proton channel of V-ATPases. Essential component of the endosomal pH-sensing machinery. May play a role in maintaining the Golgi functions, such as glycosylation maturation, by controlling the Golgi pH.
Specificity
Natural and recombinant Human V-type proton ATPase 116 kDa subunit a isoform 2
Subcellular Location
Cell membrane Multi-pass membrane protein Endosome membrane In kidney proximal tubules, also detected in subapical vesicles.
The V-ATPase is an heteromultimeric enzyme composed of at least thirteen different subunits. It has a membrane peripheral V1 sector for ATP hydrolysis and an integral V0 for proton translocation. The V1 sector comprises subunits A-H, whereas V0 includes subunits a, d, c, c', and c''. Directly interacts with PSCD2 through its N-terminal cytosolic tail in an intra-endosomal acidification-dependent manner. Disruption of this interaction results in the inhibition of endocytosis.