Dolichol Phosphate GlcNAc-1-P Transferase
Asparagine-linked glycosylation is a covalent modification of secretory and integral membrane proteins in eukaryotes that modulates the structure and function of these proteins. Dolichol-linked oligosaccharides are transferred en bloc to selected asparagine residues of nascent polypeptides. Biosynthesis of the dolichol-bound oligosaccharides is initiated by formation of GlcNAc-P-P-dolichol from UDP-GlcNAc and dolichol phosphate. This reaction is catalyzed by the endoplasmic reticulum (ER) residential enzyme UDP-GlcNAc:dolichol phosphate N-acetylglucosamine-1- phosphate transferase (GPT). The two substrates, dolichol phosphate and UDP- GlcNAc, can serve other pathways, but the product of GPT activity can only participate in lipid-bound oligosaccharide biosynthesis. Thus, GPT catalyzes the committed step of the dolichol cycle involved in asparagine-linked glycosylation.
KeywordsALG7 Gene Negative Regulatory Element Heterologous Complementation Dolichol Phosphate Polyprenyl Phosphate
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- Eckert V, Blank M, Mazhari-Tabrizi R, Mumberg D, Funk M, Schwarz RT (1998) Cloning and functional expression of the human GlcNAc-1-P transferase, the enzyme for the committed step of the dolichol cycle, by heterologous complementation in Saccharomyces cerevisiae. Glycobiology 8:77–85PubMedCrossRefGoogle Scholar
- Huang GT, Lennon K, Kukuruzinska MA (1998) Characterization of multiple transcripts of the hamster dolichol-P-dependent N-acetylglucosmanie-1-P transferase suggests functionally complex expression. Mol Cell Biol 18:97–106Google Scholar
- Palamarczyk G, Lehle L, Mankowski T, Chonacki T, Tanner W (1980) Specificity of solubilized yeast glycosyltransferases for polyprenyl derivatives. Eur J Biochem 263:17499–17507Google Scholar
- Shailubhai K, Dong-Yu B, Saxena ES, Vijay IK (1988) Purification and characterization of UDP-N-acetylglucosamine:dolichol phosphate N-acetyl-D-glucosamine-l-phosphate transferase involved in the biosynthesis of asparagine-linked glycoprotein in the mammary gland. J Biol Chem 263:15964–15972PubMedGoogle Scholar
- Tamura G (ed) (1982) Tunicamycin. Japan Scientific Societies Press, Tokyo Zar J, Lehrman MA (1994) Role of the carboxyl terminus in stable expression of hamster UDP-GlcNAc:dolichol phosphate GlcNAc-1-P transferase. J Biol Chem 269:19108–19115Google Scholar