Extracellular matrix assembly of cell-derived and plasma-derived fibronectins by substrate-attached fibroblasts

✍ Scribed by Andrea E. Allio; Paula J. McKeown-Longo

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 855 KB
• Volume: 135
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041350313

✦ Synopsis

Using a previously described model system for the incorporation of plasma fibronectin into the extracellular matrix (McKeown-Longo, P.J. and Mosher, D.F., 1985. J. Cell Biol., 100:364-374), we compared the binding of cell-derived and plasma-derived fibronectins to human fibroblast cell layers. Binding was measured in time course experiments using metabolically labeled cell-derived, iodinated cell-derived, and iodinated plasma-derived fibronectins. The kinetics of matrix assembly of cell-and plasma-derived fibronectins were the same. Competitive binding curves using intact fibronectin or the 70-kD amino-terminal fragment of fibronectin suggested that cell surface binding sites have equal affinity for cell-and plasma-derived fibronectins. lodinated fibronectins did not bind to isolated matrices containing collagen type I, fibronectin, and thrombospondin. These results suggest that fibroblasts do not distinguish between cell-derived and plasma-derived fibronectins when assembling exogenous fibronectin into extracellular matrix.