NCAM-MEDIATED ADHESION OF TRANSFECTED CELLS TO AGRIN

The vertebrate neural cell adhesion molecule NCAM mediates heterophili c adhesion to heparan sulfate proteoglycans in embryonic chick brain m embranes. In this study, mouse L cells transfected with chicken NCAM w ere used to identify two of these ligands as agrin and the target of t he 6C4 monoclonal antibody. A third heparan sulfate proteoglycan, perl ecan, appeared not to support NCAM-mediated adhesion. Enzymatic degrad ation of chondroitin sulfates decreased adhesion in agrin-containing m embrane fractions but increased adhesion if the agrin had previously b een removed by immunoprecipitation, suggesting that interactions betwe en heparan sulfate and chondroitin sulfate proteoglycans have importan t influences on adhesion. Our experiments support the view that NCAM c an interact with multiple, but not with all, heparan sulfate and chond roitin sulfate proteoglycans in chick brain membranes in both positive and negative ways to influence cell adhesion.