RhoGAP Proteins and Enzymes

The p190 Rho GTPase activating protein RhoGAP) family includes two closely related proteins, p190-A and p190-B. p190-B contains an N-terminal GTPase domain and a C-terminal Rho-GAP domain (1). p190-B can be directly phosphorylated on a single identified tyrosine residue by the activated insulin and IGF-1 receptors. This phosphorylation causes p190-B to translocate to the lipid rafts of the plasma membrane, where it can facilitate the inactivation of the Rho GTPase. P190-B also has been shown to be tyrosine phosphorylated by c-Src and v-Src. Additionall; the GAP domain of p190-B as shown to attenuate signal-transducing activity of Rac, Rho and CDC42 (2-3).