Functionally distinct roles for glycosylation of alpha and beta integrin chains in cell-matrix interactions.
Laminin interaction with gp120/140, a B16-F10 laminin-binding protein immunologically related to alpha 6 beta 1 integrin, has been shown to be dependent on oligosaccharides from both ligand and receptor. Lectin analysis of gp120/140 led to the conclusion that this integrin is a sialoglycoprotein bearing mainly complex antennary structures. By means of exoglycosidase treatment, it was possible to identify alpha-galactosyl residues on the integrin alpha chain as the laminin-binding determinants. These residues are involved in cell adhesion to laminin. On the other hand, beta-chain complex antennary structures, whose synthesis could be inhibited by swainsonine, were associated with cell spreading rather than cell adhesion. Thus, it was possible to modulate integrin-mediated cell adhesion and spreading through changes in the glycosylation state of integrin alpha and beta chains.
Chammas
R
R
Ludwig Institute for Cancer Research, São Paulo, Brazil.
Veiga
S S
SS
Travassos
L R
LR
Brentani
R R
RR
D000818:Animals; D002448:Cell Adhesion; D005109:Extracellular Matrix / Q000502:physiology*; D006031:Glycosylation; D066298:In Vitro Techniques; D016023:Integrins / Q000378:metabolism*; D007797:Laminin / Q000378:metabolism*; D037102:Lectins / Q000378:metabolism; D008546:Melanoma, Experimental / Q000473:pathology; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D011485:Protein Binding; D014407:Tumor Cells, Cultured
D016023:Integrins; D007797:Laminin; D037102:Lectins; D008562:Membrane Glycoproteins; C029967:nidogen