Characterization of the role of RhoA and Rac1 in cytoskeletal signaling. (A) The effect of SDF1 on the activation of key proteins in cytoskeletal signaling including RhoA, Rac1, LIMK, FAK, SRC, cofilin, MLC and AKT detected by immunoblotting. SDF1 was shown to induce fast activation of those proteins 1 minute after treatment. (B) The effect of ROCK and Rac1 inhibitors on the activation of cytoskeletal proteins, detected by immunoblotting. (C) The effect of inhibitors of coupling of G-protein, PI3K, and AKT on the SDF1-induced activation of RhoA and Rac1 GTPases, detected by immunoblotting. (D) The effect of inhibitors of coupling of G-protein, PI3K, and AKT on the SDF1-induced chemotaxis of MM1S cells. The effect of ROCK and Rac1 inhibitors on MM cell (E) chemotaxis and (F) adhesion to fibronectin induced by SDF1 in the presence or absence of PI3K inhibitor. *P < .05; #P < .01.