Many eukaryotic cell surface proteins are bound to the cell membrane by a
glycosylphosphatidylinositol (GPI) anchor. Several genes involved in GPI anchor
biosynthesis have been cloned using complementation of mutant mammalian cell lines and
yeasts that are defective in its biosynthesis pathway. However, the gene involved in the
second step of this pathway, in whichN-acetylglucosaminyl-phosphatidylinositol (GlcNAc-PI)
isN-deacetylated to form glucosaminyl (GlcN)-PI, has not been cloned. In this study, we …