The Regulation of Integrin-mediated Cell Adhesion and Spreading by the Actin-binding Protein Filamin A

Cell adhesion and spreading are regulated by complex interactions between the cytoskeleton, matrix adhesion receptors and extracellular matrix proteins, but the molecular determinants of these interactions in early events in cell spreading are not defined. I found that the actin-binding proteins cortactin, vinculin and filamin A were enriched in the earliest formed extensions of HEK-293 cells spreading on collagen. Knockdown of filamin A by short hairpin RNA reduced spreading and the number of cell extensions. Antibody blockade of collagen binding sites on ß1 integrin reduced (p