This family of proteins represents subunit Y of the GPI-N-acetylglucosaminyltransferase (GPI-GnT) complex. It may regulate activity of the complex by binding the catalytic subunit, PIG-A [1]. This family includes the ERI1 subunit found in yeast, such as Swiss:P62651 [2].

1: The initial enzyme for glycosylphosphatidylinositol biosynthesis requires PIG-Y, a seventh component. Murakami Y, Siripanyaphinyo U, Hong Y, Tashima Y, Maeda Y, Kinoshita T; Mol Biol Cell. 2005;16:5236-5246. PMID:16162815

2: Yeast Ras regulates the complex that catalyzes the first step in GPI-anchor biosynthesis at the ER. Sobering AK, Watanabe R, Romeo MJ, Yan BC, Specht CA, Orlean P, Riezman H, Levin DE; Cell. 2004;117:637-648. PMID:15163411