Article abstract
Nature Cell Biology 3, 353 - 360 (2001)
Published online: 6 March 2001 | doi:10.1038/35070029
Spatial regulation of the exocyst complex by Rho1 GTPase
Wei Guo1,3, Fuyuhiko Tamanoi2 & Peter Novick1
Abstract
Spatial regulation of membrane traffic is fundamental to many biological processes, including epithelial cell polarization and neuronal synaptogenesis. The multiprotein exocyst complex is localized to sites of polarized exocytosis, and is required for vesicle targeting and docking at specific domains of the plasma membrane. One component of the complex, Sec3, is thought to be a spatial landmark for polarized exocytosis. We have searched for proteins that regulate the polarized localization of the exocyst in the budding yeast Saccharomyces cerevisiae. Here we report that certain rho1 mutant alleles specifically affect the localization of the exocyst proteins. Sec3 interacts directly with Rho1 in its GTP-bound form, and functional Rho1 is needed both to establish and to maintain the polarized localization of Sec3. Sec3 is not the only mediator of the effect of Rho1 on the exocyst, because some members of the complex are correctly targeted independently of the interaction between Rho1 and Sec3. These results reveal the action of parallel pathways for the polarized localization of the exocytic machinery, both of which are under the control of Rho1, a master regulator of cell polarity.
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520-8002, USA
- Department of Microbiology and Molecular Genetics, Molecular Biology Institute, University of California, Los Angeles, California 90095-1489, USA
- Current address: Biology Department, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
Correspondence to: Peter Novick1 e-mail: peter.novick@yale.edu
