Glycosylphosphatidylinositol (GPI) represents an important anchoring molecule for cell surface proteins.The first step in its synthesis is the transfer of N-acetylglucosamine (GlcNAc) from UDP-N-acetylglucosamine to phosphatidylinositol (PI). This chemically simple step is genetically complex because three or four genes are required in both yeast (GPI1, GPI2 and GPI3) and mammals (GPI1, PIG A, PIG H and PIG C), respectively [1].

1: The GPI1 homologue from Plasmodium falciparum complements a Saccharomyces cerevisiae GPI1 anchoring mutant. Shams-Eldin H, Azzouz N, Kedees MH, Orlean P, Kinoshita T, Schwarz RT; Mol Biochem Parasitol 2002;120:73-81. PMID:11849707

2: Gpi1, a Saccharomyces cerevisiae protein that participates in the first step in glycosylphosphatidylinositol anchor synthesis. Leidich SD, Orlean P; J Biol Chem 1996;271:27829-27837. PMID:8910381