V-type proton ATPase 116 kDa subunit a isoform 4 is an enzyme that in humans is encoded by the ATP6V0A4gene.[5][6][7]
Function
This gene encodes a component of vacuolar ATPase (V-ATPase), a multisubunit enzyme that mediates acidification of intracellular compartments of eukaryotic cells. V-ATPase dependent acidification is necessary for such intracellular processes as protein sorting, zymogen activation, receptor-mediated endocytosis, and synaptic vesicle proton gradient generation. V-ATPase is composed of a cytosolic V1 domain and a transmembrane V0 domain. The V1 domain consists of three A and three B subunits, two G subunits plus the C, D, E, F, and H subunits. The V1 domain contains the ATP catalytic site. The V0 domain consists of five different subunits: a, c, c', c'', and d. This gene is one of four genes in man and mouse that encode different isoforms of the a subunit. Alternatively spliced transcript variants encoding the same protein have been described. Mutations in this gene are associated with renal tubular acidosis associated with preserved hearing.[7]
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Brown D, Breton S (2000). "H(+)V-ATPase-dependent luminal acidification in the kidney collecting duct and the epididymis/vas deferens: vesicle recycling and transcytotic pathways". J. Exp. Biol. 203 (Pt 1): 137–45. doi:10.1242/jeb.203.1.137. PMID10600682.
Nishi T, Forgac M (2002). "The vacuolar (H+)-ATPases--nature's most versatile proton pumps". Nat. Rev. Mol. Cell Biol. 3 (2): 94–103. doi:10.1038/nrm729. PMID11836511. S2CID21122465.