Importance of N-glycosylation on alpha5beta1 integrin for its biological functions.

N-Glycosylation of proteins is conserved in eukaryotes, which is one of the most abundant post-translational modification reactions, and nearly half of all known proteins in eukaryotes are glycosylated. In fact, changes in oligosaccharide structure (glycan) are associated with many physiological and pathological events, including cell adhesion, migration, cell growth, cell differentiation and tumor invasion. Glycosylation reactions are catalyzed by the action of glycosyltransferases, which add sugar chains to various glycans on glycoproteins, glycolipids and proteoglycans. Here, we focus mainly on the modification of N-glycans with N-acetylglucosaminyltransferase III (GnT-III), N-acetylglucosaminyltransferase V (GnT-V) and alpha2,6 sialyltransferase (ST6GalI) to address the important roles of N-glycans in integrin-meditaed cell adhesion and migration. In addition, we also discuss the potential roles of N-glycosylation sites on integrin alpha5 subunit.