Protein Domain : V0 complex accessory subunit Ac45 IPR008388

Type	Family
Description	V-ATPases (also known as V1V0-ATPase or vacuolar ATPase) are found in the eukaryotic endomembrane system, and in the plasma membrane of prokaryotes and certain specialised eukaryotic cells. V-ATPases hydrolyse ATP to drive a proton pump, and are involved in a variety of vital intra- and inter-cellular processes such as receptor mediated endocytosis, protein trafficking, active transport of metabolites, homeostasis and neurotransmitter release [ ]. V-ATPases are composed of two linked complexes: the V1 complex (subunits A-H) contains the catalytic core that hydrolyses ATP, while the V0 complex (subunits a, c, c', c'', d) forms the membrane-spanning pore. V-ATPases may have an additional role in membrane fusion through binding to t-SNARE proteins [].This entry represents the V0 complex Ac45 accessory subunit (ATP6AP1, also known as V-type proton ATPase subunit S1), an ER/Golgi membrane protein. This subunit is synthesized as an N-glycosylated 60kDa precursor that is intracellularly cleaved to a protein of about 45kDa. This subunit plays a crucial role on V0 assembly, stability and function as it connects to multiple V0 subunits and phospholipids in the c-ring [ ]. This subunit assists the V-ATPase in the acidification of neuroendocrine granules [] and guides the V-ATPase into specialized subcellular compartments such as neuroendocrine regulated secretory vesicles or the ruffled border of the osteoclast []. In humans, mutations of ATP6AP1 cause immunodeficiency with hypogammaglobulinemia, hepatopathy and neurocognitive abnormalities [].
Short Name	Ac45_acc_su