The evolutionary history of effectors downstream of Cdc42 and Rac

Cdc42 and Rac - ancient, highly conserved, small GTPases - mediate extracellular signals, triggering changes in transcription and in the actin cytoskeleton. Although dozens of proteins act downstream of these GTPases, a comparison of effector proteins from evolutionarily diverse organisms suggests that six groups of proteins serve as the core machinery for signaling from Cdc42 and Rac.