Glycosyltransferases as cell adhesion molecules

Specific glycosyltransferases are believed to be present on the cell surface, where they may function as cell adhesion molecules by binding oligosaccharide substrates on adjacent cell surfaces or in the extracellular matrix. The best studied of these is beta 1,4-galactosyltransferase, which mediates sperm binding to the egg coat and selected cell interactions with the basal lamina. Molecular models have recently been presented to account for the expression of beta 1,4-galactosyltransferase on the cell surface, thus enabling one to alter its surface expression and to examine the consequences on fertilization and development.