The function of PIGU (phosphatidylinositol glycan anchor biosynthesis class U, Ensembl gene identifier ENSG00000101464) is as follows. Component of the glycosylphosphatidylinositol-anchor (GPI- anchor) transamidase (GPI-T) complex that catalyzes the formation of the linkage between a proprotein and a GPI-anchor and participates in GPI anchored protein biosynthesis (PubMed:12802054, PubMed:31353022, PubMed:34576938, PubMed:35165458, PubMed:35551457, PubMed:37684232). Binds the lipid portion of GPI-anchor (PubMed:37684232). May act as an organizer in the transmembrane layer to recruit other subunits, and thus is essential for assembly of the complex (PubMed:35165458, PubMed:35551457). {ECO:0000269|PubMed:12802054, ECO:0000269|PubMed:31353022, ECO:0000269|PubMed:34576938, ECO:0000269|PubMed:35165458, ECO:0000269|PubMed:35551457, ECO:0000269|PubMed:37684232}.