EXPERIMENTAL FIGURE 17-42 Dominant-active Rac, Rho, and Cdc42 induce different actin-containing structures. To look at the effects of constitutively active Rac, Rho, and Cdc42, growth-factor-starved fibroblasts were microinjected with plasmids to express dominant-active versions of the three proteins. The cells were then treated with fluorescent phalloidin, which stains filamentous actin. Dominant-active Rac induces the formation of peripheral membrane ruffles, whereas dominant-active Rho induces abundant contractile stress fibers, and dominant-active Cdc42 induces filopodia.

[Republished with permission of AAAS, from Hall, A., “Rho GTPases and the actin cytoskeleton,” Science, 1998, 279 (5350):509-14; permission conveyed through Copyright Clearance Center, Inc.]