The human genome includes approximately 70 genes that are predicted to encode Rho-specific GTPase Activating Proteins (RhoGAPs). As in the case of GEFs, some RhoGAPs are believed to be highly specific, whereas others are more promiscuous with respect to their target GTPases. Increasing evidence suggests that GAPs are also regulated by external cues in addition to being signal terminators leading to Rho GTPase inactivation. These proteins play important role in many Rho mediated signaling pathways.
Some known GAPs include p190 A, cdGAP, ARAP3, MgcRacGAP, Chimaerin, Nadrin, TCGAP, DLC 1, 2, ArhGAP6, Myosin IXA. These and other GAPs have been implicated in many processes, such as exocytosis, endocytosis, cytokinesis, cell differentiation, migration, neuronal morphogenesis, angiogenesis and tumor suppression. Detailed annotations of the biological role of GAPs in Rho mediated signaling will be available in future releases.