Non-catalytic subunit of the V1 complex of vacuolar(H+)-ATPase (V-ATPase), a multisubunit enzyme composed of a peripheral complex (V1) that hydrolyzes ATP and a membrane integral complex (V0) that translocates protons (PubMed:16174750, PubMed:23028982). V-ATPase is responsible for acidifying and maintaining the pH of intracellular compartments and in some cell types, is targeted to the plasma membrane, where it is responsible for acidifying the extracellular environment (By similarity). Essential for the proper assembly and activity of V-ATPase (By similarity). In renal intercalated cells, mediates secretion of protons (H+) into the urine thereby ensuring correct urinary acidification (PubMed:16174750). Required for optimal olfactory function by mediating the acidification of the nasal olfactory epithelium (PubMed:23028982). V-ATPase is a heteromultimeric enzyme made up of two complexes: the ATP-hydrolytic V1 complex and the proton translocation V0 complex (By similarity). The V1 complex consists of three catalytic AB heterodimers that form a heterohexamer, three peripheral stalks each consisting of EG heterodimers, one central rotor including subunits D and F, and the regulatory subunits C and H (By similarity). The proton translocation complex V0 consists of the proton transport subunit a, a ring of proteolipid subunits c9c'', rotary subunit d, subunits e and f, and the accessory subunits ATP6AP1/Ac45 and ATP6AP2/PRR (By similarity). Forms a complex with SLC9A3R1 and SCL4A7 (By similarity). Highly expressed in the kidney; found in early distal nephron, encompassing thick ascending limbs and distal convoluted tubules and in the alpha-intercalated cells of the cortical collecting ducts (at protein level) (PubMed:14585495, PubMed:29993276). Expressed in the olfactory epithelium (at protein level) (PubMed:23028982). Expressed at lower levels in the testis (PubMed:14585495). The PDZ-binding motif mediates interactions with SLC9A3R1 and SCL4A7. Mice show a higher urinary pH and a more severe metabolic acidosis after oral acid challenge in comparison to wild-type littermates (PubMed:16174750). Mice show diminished innate avoidance behavior (revealed as a decrease in freezing time and an increase in the number of sniffs in the presence of trimethyl-thiazoline) and diminished innate appetitive behavior (a decrease in time spent investigating the urine of the opposite sex) (PubMed:23028982). Belongs to the ATPase alpha/beta chains family.