Actin cytoskeleton organization in response to integrin-mediated adhesion

Cell matrix adhesion regulates actin cytoskeleton organization through dist inct steps, from formation of filopodia and lamellipodia in the early phase s of cell adhesion to organization of focal adhesions and stress fibers in fully adherent cells. In this review, we follow the events induced by integ rin-mediated adhesion, such as activation of GTPases Cdc42 and Rac and thei r effecters and their role in actin polymerization leading to formation of lamellipodia and filopodia and cell spreading. We also show that actin stre ss fiber and focal adhesion formation following adhesion requires cooperati on between integrin-mediated signaling and additional stimuli, including ac tivation of PKC, Rho GTPases, and PTKs such as p125Fak and Src. (C) 1999 Wi ley-Liss, Inc.