Enables proton transmembrane transporter activity. Involved in proton transmembrane transport. Acts upstream of or within several processes, including inorganic ion homeostasis; renal sodium ion transport; and renal water homeostasis. Located in several cellular components, including basolateral plasma membrane; lateral plasma membrane; and microvillus. Is expressed in several structures, including alimentary system; limb; metanephros; nervous system; and sensory organ. Used to study autosomal recessive nonsyndromic deafness and enlarged vestibular aqueduct. Human ortholog(s) of this gene implicated in renal tubular acidosis. Orthologous to human ATP6V1B1 (ATPase H+ transporting V1 subunit B1). [provided by Alliance of Genome Resources, Apr 2022]