Rho GTPase-activating proteins in cell regulation.

Rho family small GTPases serve as molecular switches involved in the regulation of diverse cellular functions including various cytoskeleton-related events and gene transcription. The Rho GTPase-activating proteins (RhoGAPs) are one of the major classes of regulators of Rho GTPases found in all eukaryotes that are crucial in cell cytoskeletal organization, growth, differentiation, neuronal development and synaptic functions. Recent studies have implicated them as specific negative regulators of Rho protein signalling pathways and provided insight into how the RhoGAP-catalysed GTPase-activating reaction might proceed. Progress has also been made in understanding how various intracellular signals might converge on or diverge from RhoGAPs leading to their tight regulation or GAP-independent function.