IUBMB Enzyme Nomenclature


Accepted name: phosphatidylinositol N-acetylglucosaminyltransferase

Reaction: UDP-N-acetyl-α-D-glucosamine + 1-phosphatidyl-1D-myo-inositol = UDP + 6-(N-acetyl-α-D-glucosaminyl)-1-phosphatidyl-1D-myo-inositol

For diagram click here.

Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns

Other name(s): UDP-N-acetyl-D-glucosamine:phosphatidylinositol N-acetyl-D-glucosaminyltransferase; uridine diphosphoacetylglucosamine α1,6-acetyl-D-glucosaminyltransferase; UDP-N-acetyl-D-glucosamine:1-phosphatidyl-1D-myo-inositol 6-(N-acetyl-α-D-glucosaminyl)transferase

Systematic name: UDP-N-acetyl-α-D-glucosamine:1-phosphatidyl-1D-myo-inositol 6-(N-acetyl-α-D-glucosaminyl)transferase (configuration-retaining)

Comments: Involved in the first step of glycosylphosphatidylinositol (GPI) anchor formation in all eukaryotes. In mammalian cells, the enzyme is composed of at least five subunits (PIG-A, PIG-H, PIG-C, GPI1 and PIG-P). PIG-A subunit is the catalytic subunit. In some species, the long-chain acyl groups of the phosphatidyl group are partly replaced by long-chain alkyl or alk-1-enyl groups.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 144388-35-2


1. Doering, T.L., Masteron, W.J., Englund, P.T. and Hart, G.W. Biosynthesis of the glycosyl phosphatidylinositol membrane anchor of the trypanosome variant surface glycoprotein. Origin of the non-acetylated glucosamine. J. Biol. Chem. 264 (1989) 11168-11173. [PMID: 2525555]

2. Watanabe, R., Inoue, N., Westfall, B., Taron, C.H., Orlean, P., Takeda, J. and Kinoshita, T. The first step of glycosylphosphatidylinositol biosynthesis is mediated by a complex of PIG-A, PIG-H, PIG-C and GPI1. EMBO J. 17 (1998) 877-885. [PMID: 9463366]

3. Watanabe, R., Murakami, Y., Marmor, M.D., Inoue, N., Maeda, Y., Hino, J., Kangawa, K., Julius, M. and Kinoshita, T. Initial enzyme for glycosylphosphatidylinositol biosynthesis requires PIG-P and is regulated by DPM2. EMBO J. 19 (2000) 4402-4411. [PMID: 10944123]

[EC created 1992, modified 2002]

Return to EC 2.4.1 home page
Return to EC 2.4 home page
Return to EC 2 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page