Type: | Family | Name: | Rho protein GDP-dissociation inhibitor |
Description: | The GDP dissociation inhibitor for rho proteins, rho GDI, regulates GDP/GTP exchange by inhibiting the dissociation of GDP from them. The protein contains 204 amino acids, with a calculated Mr valueof 23,421. Hydropathy analysis shows it to be largely hydrophilic, with a single hydrophobic region. Results of database searches suggest rho GDI isa novel protein, currently with no known homologue. The protein plays an important role in the activation of the superoxide(O2-)-generating NADPH oxidase of phagocytes. This process requires the interaction of membrane-associated cytochrome b559 with 3 cytosoliccomponents: p47-phox, p67-phox and a heterodimer of the small G-protein p21rac1 and rho GDI []. The association of p21rac and GDI inhibitsdissociation of GDP from p21rac, thereby maintaining it in an inactive form. The proteins are attached via a lipid tail on p21rac that binds to thehydrophobic region of GDI []. Dissociation of these proteins might bemediated by the release of lipids (e.g., arachidonate and phosphatidate) from membranes through the action of phospholipases []. The lipids may thencompete with the lipid tail on p21rac for the hydrophobic pocket on GDI. | Short Name: | Rho_GDI |