GPI-GlcNAc Transferase: Complex of PIG-A, PIG-C, PIG-H, hGPI1, and PIG-P
Glycosylphosphatidylinositols (GPIs) anchor proteins to the cellular plasma membrane in a wide range of eukaryotic organisms from yeasts to mammals (Kinoshita et al. 1997). The GPI-anchor is transferred en bloc to the carboxyl-terminus of protein precursors in the endoplasmic reticulum (ER). Attachment of the GPI-anchor to the proteins is essential for their expression on the cell surface. Synthesis of the GPI- anchor is initiated by transferring GlcNAc to phosphatidylinositol (PI) and proceeds by de-N-acetylation of GlcNAc, acylation of myoinositol, and addition of three man- noses and three ethanolamine phosphates in mammalian cells (see Appendix Map- 5). The basic structure and biosynthetic pathway are conserved in various organisms. The UDP-GlcNAc:PI-α1-4GlcNAc transferase (GPI-GlcNAc transferase, or GPI-GnT) catalyzes the first reaction in the biosynthesis of the GPI-anchor.
KeywordsParoxysmal Nocturnal Hemoglobinuria Fatty Acyl Chain Conditional Knockout Mouse Piga Gene Paroxysmal Nocturnal Hemoglobinuria Patient
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