This entry represents the transmembrane domain from ER/Golgi membrane proteins including V0 complex accessory subunit Ac45 (ATP6AP1, also known as V-type proton ATPase subunit S1) from animals and the yeast homologue V0 assembly protein 1 (VOA1) which are essential for V0 ATPase assembly, stability and function [1,2]. In humans, mutations of ATP6AP1 cause immunodeficiency with hypogammaglobulinemia, hepatopathy and neurocognitive abnormalities [3]. This entry also includes ER membrane BIG1 proteins from yeast, involved in cell wall biogenesis.

1: Structures of a Complete Human V-ATPase Reveal Mechanisms of Its Assembly. Wang L, Wu D, Robinson CV, Wu H, Fu TM; Mol Cell. 2020;80:501-511. PMID:33065002

2: Voa1p functions in V-ATPase assembly in the yeast endoplasmic reticulum. Ryan M, Graham LA, Stevens TH; Mol Biol Cell. 2008;19:5131-5142. PMID:18799613

3: ATP6AP1 deficiency causes an immunodeficiency with hepatopathy, cognitive impairment and abnormal protein glycosylation. Jansen EJ, Timal S, Ryan M, Ashikov A, van Scherpenzeel M, Graham LA, Mandel H, Hoischen A, Iancu TC, Raymond K, Steenbergen G, Gilissen C, Huijben K, van Bakel NH, Maeda Y, Rodenburg RJ, Adamowicz M, Crushell E, Koenen H, Adams D, Vodopiutz J, Greber-Platzer S, Muller T, Dueckers G, Morava E, Sykut-Cegielska J, Martens GJ, Wevers RA, Niehues T, Huynen MA, Veltman JA, Stevens TH, Lefeber DJ; Nat Commun. 2016;7:11600. PMID:27231034