Fibronectin.

Fibronectin is a glycoprotein consisting of repeating units of amino acids, which form domains that enable the molecule to interact with a variety of cells through both integrin and non-integrin receptors. It is encoded by a single gene, but alternative splicing of pre-mRNA allows formation of multiple isoforms that have critical roles in cell adhesion, migration and proliferation. The essential nature of fibronectin in development has clearly been demonstrated in a "knock-out" mouse model in which early lethality occurs. Fibronectin influences diverse processes including inflammation, wound repair, malignant metastasis, microorganism attachment and thrombosis. Researchers are currently developing tools, including synthetic peptides based on specific fibronectin regions. These molecules have been shown to alter processes such as lymphocyte binding in synovial tissue of rheumatoid arthritis, coronary arteriopathy in animal models of cardiac transplantation, and platelet aggregation in patients, and are thus providing important new therapeutic possibilities.