Subunit of the V0 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 (By similarity). 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). Involved in normal vectorial acid transport into the urine by the kidney (By similarity). 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). Interacts with the V1 complex V-ATPase subunit A ATP6V1A (PubMed:11498539). Interacts with the V0 complex V-ATPase subunit c ATP6V0C (PubMed:11498539). Localizes to the apical surface of alpha-intercalated cells in the cortical collecting ducts of the distal nephron (PubMed:11498539, PubMed:11495928). Localizes to the basolateral surface of beta-intercalated cells in the cortical collecting ducts of the distal nephron (PubMed:11498539, PubMed:11495928). Specifically expressed in kidney, but not in the heart, brain, spleen, lung, liver, muscle, or testis. Distribution within the kidney appears more widespread than that seen in man. High intensity staining at the surface of intercalated cells, with additional expression in the proximal tubule. Belongs to the V-ATPase 116 kDa subunit family.