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Updated: Jul 15, 2026
11:27
X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
X-ray crystal structures reveal two activated states for RhoC
Sandra M G Dias1, Richard A Cerione
1Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
Biochemistry
|May 15, 2007
Summary
RhoC, a small GTPase, undergoes distinct conformational changes upon activation compared to RhoA. These differences in switch domains explain RhoC's role in cancer cell invasiveness and metastasis.
Area of Science:
- Molecular biology
- Structural biology
- Biochemistry
Background:
- RhoC is a Rho family GTPase similar to RhoA but with distinct functions, including cancer cell invasiveness.
- Previous structural studies of RhoC were limited, hindering understanding of its activation mechanism.
Purpose of the Study:
- To structurally compare GDP-bound (inactive) and GTP-bound (active) states of RhoC.
- To elucidate the molecular basis of RhoC activation and its functional specificity compared to RhoA.
Main Methods:
- X-ray crystallography of RhoC in GDP-bound and GTP-bound states using non-hydrolyzable GTP analogs (GppNHp, GTPgammaS).
- Comparative structural analysis of RhoC switch I and switch II domains.
Main Results:
- GppNHp-bound RhoC showed differences in the switch II domain compared to GDP-bound RhoC.
- GTPgammaS-bound RhoC exhibited changes in both switch I and switch II domains.
- RhoC undergoes at least two conformational transitions upon activation, unlike RhoA's single transition.
Conclusions:
- RhoC's activation involves multiple conformational states, explaining its distinct effector binding and cellular roles.
- Structural differences in switch domains between RhoA and RhoC underpin their functional specificity in cellular processes like metastasis.
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