Module 2: Figure Cdc42 signalling
Function of the Cdc42 monomeric G protein in signal transduction.
When bound to GDP, Cdc42 is inactive, but it is activated when the GDP is exchanged for GTP. This exchange is accelerated by guanine nucleotide exchange factors (GEFs), but how these are activated is still somewhat of a mystery. The primary action of the Cdc42/GTP complex is to stimulate actin assembly by inhibiting the action of cofilin, by promoting actin polymerization by acting on actin/profilin and Wiskott–Aldrich syndrome protein (WASP). Further details on the role of WASP are shown in Module 4: Figure actin remodelling.