Phosphatidylinositol N-acetylglucosaminyltransferase

In enzymology, a phosphatidylinositol N-acetylglucosaminyltransferase (EC 2.4.1.198) is an enzyme that catalyzes the chemical reaction

UDP-N-acetylglucosamine + phosphatidylinositol ${\displaystyle \rightleftharpoons }$ UDP + N-acetyl-D-glucosaminylphosphatidylinositol

phosphatidylinositol N-acetylglucosaminyltransferase
Identifiers
EC no.	2.4.1.198
CAS no.	144388-35-2
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Thus, the two substrates of this enzyme are UDP-N-acetylglucosamine and phosphatidylinositol, whereas its two products are UDP and N-acetyl-D-glucosaminylphosphatidylinositol.

The mammalian enzyme is composed of at least six subunits (PIG-A, PIG-H, PIG-C, PIG-P, PIG-Y, and GPI1). PIG-A is the catalytic subunit.

This enzyme belongs to the family of glycosyltransferases, to be specific the hexosyltransferases. The systematic name of this enzyme class is UDP-N-acetyl-D-glucosamine:1-phosphatidyl-1D-myo-inositol 6-(N-acetyl-alpha-D-glucosaminyl)transferase. Other names in common use include UDP-N-acetyl-D-glucosamine:phosphatidylinositol, N-acetyl-D-glucosaminyltransferase, uridine diphosphoacetylglucosamine, and alpha1,6-acetyl-D-glucosaminyltransferase. This enzyme participates in 3 metabolic pathways: glycosylphosphatidylinositol(gpi)-anchor, ???, and glycan structures - biosynthesis 2.

References

• Doering TL, Masterson WJ, Englund PT, Hart GW (July 1989). "Biosynthesis of the glycosyl phosphatidylinositol membrane anchor of the trypanosome variant surface glycoprotein. Origin of the non-acetylated glucosamine". The Journal of Biological Chemistry. 264 (19): 11168–73. PMID 2525555.
• Watanabe R, Inoue N, Westfall B, Taron CH, Orlean P, Takeda J, Kinoshita T (February 1998). "The first step of glycosylphosphatidylinositol biosynthesis is mediated by a complex of PIG-A, PIG-H, PIG-C and GPI1". The EMBO Journal. 17 (4): 877–85. doi:10.1093/emboj/17.4.877. PMC 1170437. PMID 9463366.
• Watanabe R, Murakami Y, Marmor MD, Inoue N, Maeda Y, Hino J, Kangawa K, Julius M, Kinoshita T (August 2000). "Initial enzyme for glycosylphosphatidylinositol biosynthesis requires PIG-P and is regulated by DPM2". The EMBO Journal. 19 (16): 4402–11. doi:10.1093/emboj/19.16.4402. PMC 302040. PMID 10944123.