Integrin signalling: a new Cas(t) of characters enters the stage

Cellular morphology is determined by the organization of the intracellular actin cytoskeleton, which is influenced by external and internal cues. Foca l adhesions are sites at which the actin cytoskeleton is linked to the extr acellular matrix by integrin receptor complexes. In addition to providing s tructural tethering points for cells, integrin receptor complexes transduce signals that influence a broad range of cellular processes, including migr ation, proliferation, transformation and apoptosis. The Cas proteins (p130C as, HEF1/Cas-L and Efs/Sin), a family of docking proteins containing multip le interaction domains, are important components of integrin receptor signa lling and have been implicated in all of these processes.