Fig. 5.

Cdc42 and its effectors: Cdc42 induces actin polymerization by binding to WASP, or through IRSp53. PAK is a downstream effector of Cdc42 that activates LIM kinase (LIMK) leading to inhibition of cofilin. PAK phosphorylates CRAF and MEK activating the MAP kinase pathway and indirectly actin polymerization. FMNL2 was recently characterized as a downstream effector of Cdc42 that modulates actin polymerization at the lamellipodium tip. Cdc42 also contributes to cell polarity by interacting with the PAR complex