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Updated: May 24, 2026
11:28
Affinity Precipitation of Active Rho-GEFs Using a GST-tagged Mutant Rho Protein (GST-RhoA(G17A)) from Epithelial Cell Lysates
Published on: March 31, 2012
Functional specialisation of yeast Rho1 GTP exchange factors.
Sue Ann Krause1, Michael J Cundell, Pak P Poon
1School of Life Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
Journal of Cell Science
|February 21, 2012
Summary
The study reveals distinct roles and localizations for yeast Rho1 GTPase activators, Rom2 and Tus1. These GTP exchange factors (GEFs) are not interchangeable, highlighting specialized control of Rho1 signaling.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Rho GTPases regulate diverse cellular processes.
- GTP exchange factors (GEFs) control Rho GTPase activation.
- Multiple GEFs for a single GTPase suggest functional specialization.
Purpose of the Study:
- To investigate functional specialization of yeast Rho1 GEFs, Rom2 and Tus1.
- To determine the basis for differential roles of Rom2 and Tus1.
- To understand the spatiotemporal regulation of Rho1 GTPase.
Main Methods:
- Functional assays to assess Rho1-effector branch activation.
- Synthetic genetic network analysis to determine in vivo roles.
- Localization studies using microscopy.
- Co-factor dependency analysis.
Main Results:
- Rom2 and Tus1 selectively activate different Rho1 effector pathways.
- Synthetic genetic interactions reveal distinct global roles for Rom2 and Tus1.
- Tus1 cannot functionally replace essential Rom2.
- Rom2 and Tus1 exhibit distinct subcellular localizations (bud surface, bud neck).
- Rom2 requires Ack1; Tus1 requires Rgl1 (Ypl066w) for function and localization.
Conclusions:
- Rom2 and Tus1 are functionally specialized GEFs for yeast Rho1.
- Differential localization and co-factor dependence contribute to Rho1 spatiotemporal control.
- Functional diversity among Rho1 GEFs adds complexity to Rho1 regulation.
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