High resolution

Module 2: Figure Rac signalling

Function of the Rac monomeric G protein in signal transduction.

Rac is inactive when bound to GDP, but switches into an active form when this GDP is exchanged for GTP. This GTP for GDP exchange is facilitated by a number of guanine nucleotide exchange factors (GEFs) such as Tiam, Kalirin, Vav, SoS and P-Rex, which are sensitive to various messengers such as Ca2+, PtdIns3,4,5P3 (PIP3) or Gβγ subunits of heterotrimeric G proteins. The activated Rac/GTP then relays information out to different signalling pathways as described in the text. Further details concerning the role of Wiskott–Aldrich syndrome protein (WASP) verprolin homologous (WAVE) are shown in Module 4: Figure actin remodelling.