Role of Glycosylation in Ligand-Receptor Interactions and Signal Transduction Mechanisms
Glycosylation of secreted as well as membrane bound proteins in eukaryotic systems represents the most widely occurring covalent and post-translational modification during their biosynthesis. Their wide spectrum of biological activities viz, as membrane receptors, lectins, enzymes, carriers, structural components, hormones, growth stimulatory/ inhibitory factors, accounts for their ubiquitous nature. Although many glycoproteins contain both N-linked as well as O-linked oligosaccharides, the major pathways and the numerous enzymes involved only in the biosynthesis of asparagine linked sugars have been extensively investigated (Schachter et al., 1983; Kornfeld and Kornfeld, 1985). For N-glycosylation the presence of a consensus sequence in the protein Asn-X-Ser (Thr), where X can be any amino acid except proline or aspartic acid, is a necessary but not a sufficient condition in itself. Similar recognition sequence(s) for sites of O-glycosylation are not precisely known. The asparagine linked oligosaccharides are synthesized from a common core precursor, with a structure Glc3 Man9 GlcNAc2, which is then transferred as a unit from the lipid carrier dolichol phosphate to the growing nascent polypeptide chain.
KeywordsSialic Acid Zona Pellucida Carbohydrate Moiety Sugar Chain Glycoprotein Hormone
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- Bahl, O. P., and Kalyan, N. K., 1983, in: “Role of Peptides and Proteins in Control of Reproduction”, S. M. McCann, and D. S. Dhindsa, eds., Elsevier, New York, p. 293.Google Scholar
- Bahl, O. P., Thotakura, N. R., and Anumula, K. R., 1984, in: “Hormone Receptors in Growth and Reproduction”, B. B. Saxena, K. J. Catt, L. Birnbaumer, and L. Martini, eds., Raven Press, New York, p. 163.Google Scholar
- Chappel, S. C., 1988, See this volume.Google Scholar
- Greene, E. D., Boime, L, and Baenziger, J. U., 1986, J. Biol. Chem., 261:16309.Google Scholar
- Merlier, J. P., Sebbane, R., Tzartos, S., and Lindstrom, J., 1982, J. Biol. Chem., 257:2694.Google Scholar
- Parsons, T. F., Bloomfield, G. A., and Pierce, J. G., 1982, J. Biol. Chem., 258:240.Google Scholar
- Reichert, L. E., Jr., and Abou-Issa, H., 1976, in: “Hormone-Receptor Interaction Molecular Aspects”, G. Levey, ed., Dekker, New York, p. 153.Google Scholar
- Sairam, M. R., 1983, in: “Hormonal Proteins and Peptides”, C. H. Li, ed., Academic Press, New York, Vol. XI, p. 1.Google Scholar
- Sairam, M. R., 1985, in: “The Receptors”, P. M. Conn, ed., Academic Press, New York, Vol. II, p. 307.Google Scholar