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Updated: Jun 24, 2026

RhoC GTPase Activation Assay
Published on: August 23, 2010
Structure of the Rho family GTP-binding protein Cdc42 in complex with the multifunctional regulator RhoGDI
G R Hoffman1, N Nassar, R A Cerione
1Department of Molecular Medicine, Veterinary Medical Center, Cornell University, Ithaca, New York 14853, USA.
Abstract:
The RhoGDI proteins serve as key multifunctional regulators of Rho family GTP-binding proteins. The 2.6 A X-ray crystallographic structure of the Cdc42/RhoGDI complex reveals two important sites of interaction between GDI and Cdc42. First, the amino-terminal regulatory arm of the GDI binds to the switch I and II domains of Cdc42 leading to the inhibition of both GDP dissociation and GTP hydrolysis. Second, the geranylgeranyl moiety of Cdc42 inserts into a hydrophobic pocket within the immunoglobulin-like domain of the GDI molecule leading to membrane release. The structural data demonstrate how GDIs serve as negative regulators of small GTP-binding proteins and how the isoprenoid moiety is utilized in this critical regulatory interaction.
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