Matrix assembly of recombinant fibronectin polypeptide consisting of amino-terminal 70 kDa and carboxyl-terminal 37 kDa regions.

Three different forms of recombinant human fibronectin polypeptides consisting of the amino-terminal 70 kDa region, the carboxyl-terminal 37 kDa region, or both, were expressed in mouse L cells. Although either the amino-terminal or the carboxyl-terminal region alone was only poorly incorporated into the extracellular matrix, the fused form of the polypeptide was highly capable of assembling into the matrix. These results indicate that matrix assembly of fibronectin requires both regions and can proceed in the absence of the type III repeats including the one containing the cell adhesive Arg-Gly-Asp sequence.