Peptide and Carbohydrate Moieties as Molecular Signals in Animal Cell Recognition
Résumé
Cell to cell and to substratum interactions are usually mediated by specific ligands and receptors. During the last decade, various cell surface receptors were evidenced, they include carbohydrate binding and peptide binding proteins. Cell surface carbohydrate specific receptors may be lectins (Goldstein et al, 1980), ectoglycosyltransferases or glycosidases. Glycolipids, glycoproteins and proteoglycans have been shown to interact with lectins on the surface of a large number of animal cells as well as parasites, bacteria and viruses (for reviews, see Monsigny et al, 1979, 1983, 1984 a, Monsigny 1984, Ashwell and Harford 1982, Liener et al, 1986, Lis and Sharon 1986, Mirelman, 1986, Sharon, 1984). Conversely, a given cell expresses on its surface a set of specific glycoconjugates which may be involved in recognition mechanisms. These glycoconjugates include glycolipids, glycoproteins and glycosaminoglycans (see Schrével et al., 1981 for a review on the cytochemistry of cell surface glycoconjugates). Their biosynthesis involves a number of different glycosyltransferases, glycosidases and/or epimerases and sulfotransferases. The nature and the number of the glycoconjugates are modulated depending on the type, on the maturation or on the transformation state of cells.