Functional differences in the interactions of glycosylation‐deficient cell lines with fibronectin, laminin, and type IV collagen

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Abstract
Fibronectin isolated from the conditioned medium of monolayer cultures of baby hamster kindey (BHK) cells and several ricin‐resistant (Ric®) mutants derived from them express differences in N‐glycosylation. The asparaginelinked oligosaccharides of BHK cell‐derived fibronectin consist largely of complex chains, whereas hybrid and/or high‐mannose chains are present in the fibronectins of mutant cell lines. The fibronectins exhibiting different glycosylation patterns are incorporated to similar extents into the cell‐layer of human skin fibroblasts. In contrast, mutant cells retain significantly less endogenously produced fibronectin than BHK cells and also incorporate less human cellular fibronectin into a pericellular matrix. In vitro adhesion assays show that mutant cells attach to and spread relatively poorly on fibronectinor type IV collagen‐coated substrata but interact as well as do BHK cells with a laminin substratum. These results indicate that asparagine‐linked oligosaccharides of fibronectin are not required for the binding and incorporation of the molecule into cell layers, but, as constituents of other cellular glycoproteins, they do modulate the ability of BHK cells to interact with some matrix components.