ATP6B1 encodes one of the B-subunit isoforms of vacuolar ATPase (V-ATPase), which facilitates acidification of intracellular organelles. V-ATPase consists of a transmembrane and a cytosolic domain, both of which are composed of multiple subunits. The protein encoded by ATP6B1 is part of the V1 cytosolic domain that holds the catalytic site. V-ATPase is expressed throughout the body and is involved in various intracellular processes such as receptor-mediated endocytosis, synaptic vesicle proton gradient generation and protein sorting.
Mutations in the ATP6B1 gene is linked to nephrolithiasis and distal renal tubular acidosis associated with sensorineural deafness.