Small G Protein Inhibitors

Like G_α proteins, small GTPases alternate between an 'on' state (bound to GTP) and an 'off' state (bound to GDP) and so function as binary switches that regulate cytosolic signaling pathways. GDP/GTP cycling is controlled by two types of regulatory proteins that associate with small GTPases. Guanine exchange factors (GEFs) promote the formation of the active, GTP bound form of RAS proteins while GTPase activating proteins (GAPs) accelerate GTPase activity, promoting the inactive, GDP bound form.