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Updated: Jul 10, 2026
13:51
Detection of Small GTPase Prenylation and GTP Binding Using Membrane Fractionation and GTPase-linked Immunosorbent Assay
Published on: November 11, 2018
Geranylgeranylation but not GTP loading determines rho migratory function in T cells
Sonia Waiczies1, Ivo Bendix, Timour Prozorovski
1Cecilie-Vogt-Clinic for Molecular Neurology, Charité-University Medicine and Max Delbruck Center for Molecular Medicine, Berlin, Germany.
Journal of Immunology (Baltimore, Md. : 1950)
|October 20, 2007
Summary
Geranylgeranylation, not GTP loading, is crucial for RhoA function in T cell migration. Depleting geranylgeranyl pyrophosphate with atorvastatin blocks T cell infiltration into the brain.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Rho GTPases are key regulators of cell signaling pathways controlling cell migration.
- Their activity relies on GTP binding and isoprenylation, a process requiring geranylgeranyl pyrophosphate (GGpp).
Purpose of the Study:
- To investigate the role of geranylgeranylation versus GTP loading in RhoA-mediated signaling and T cell migration.
- To determine if inhibiting geranylgeranylation can prevent T cell infiltration in an inflammatory disease model.
Main Methods:
- Depletion of GGpp using atorvastatin, a 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor.
- Analysis of RhoA localization, GTP loading, and downstream kinase activation (ROCK1).
- Assessment of T cell cytoskeleton integrity and migration towards chemokines.
- In vivo studies using a rodent model of multiple sclerosis and multiphoton microscopy.
Main Results:
- GGpp depletion caused RhoA to move from the membrane to the cytosol in human T cells.
- Despite increased GTP loading, RhoA substrate activation was blocked.
- T cells showed impaired cytoskeleton formation and reduced migration.
- Atorvastatin treatment in vivo significantly reduced T cell trafficking into the brain in a multiple sclerosis model.
Conclusions:
- Geranylgeranylation, which tethers RhoA to the membrane, is essential for T cell migration.
- Inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, like atorvastatin, can prevent T cell infiltration into inflamed tissues by disrupting RhoA membrane localization.
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