Cell adhesion and integrin binding to recombinant human fibrillin-1.

Fibrillin-1 is a major constituent of tissue microfibrils that occur in most connective tissues, either in close association with or independent of elastin. To test possible cell-adhesive functions of this protein, we used recombinant human fibrillin-1 polypeptides produced in a mammalian expression system in cell attachment and solid-phase integrin binding assays. Fibrillin-1 polypeptides containing the single RGD sequence located in the fourth 8-cysteine domain, mediated distinct cell adhesion of a variety of cell lines and bound to purified integrin alphaVbeta3. Integrins alphaIIbbeta3, alpha5beta1, alpha2beta1 and alpha1beta1 did not interact with any of the recombinant fibrillin-1 peptides. Our results indicate a novel role for fibrillin-1 in cellular interactions mediated via an RGD motif that is appropriately exposed for recognition by integrin alphaVbeta3.