p21-activated protein kinase: a crucial component of morphological signaling?

The mechanisms by which Rho family GTPases (Rho, Rac and Cdc42) regulate co ordinated changes to the actin cytoskeleton are being elucidated. This revi ew will focus on the current evidence that the p21-activated kinases (PAKs) are involved in regulating some of the diverse cytoskeletal changes induce d by Rac and Cdc42. PAKs have been shown to be required for processes inclu ding neurite formation and axonal guidance, development of cell polarity an d motile responses. Signaling molecules interacting with PAKs that might co ntribute to the regulation of such processes have recently been identified.