Phosphatidylinositol Glycan U (PIGU)

Many eukaryotic proteins are anchored to the cell surface via glycosylphosphatidylinositol (GPI), which is posttranslationally attached to their C termini by GPI transamidase at the endoplasmic reticulum. PIGU is a critical subunit of mammalian GPI transamidase.The deduced 435-amino acid protein contains 9 putative transmembrane domains and shares 97% identity with rat Pigu. SDS/PAGE analysis demonstrated that PIGU has an apparent molecular mass of 38 kD.CDC91L1 was amplified and overexpressed in about one-third of bladder cancer cell lines and primary tumors examined, as well as in oncogenic uroepithelial cells transformed with human papillomavirus E7.