1. SH3BP1, an exocyst-associated RhoGAP, inactivates Rac1 at the front to drive cell motility.
- Author
-
Parrini MC, Sadou-Dubourgnoux A, Aoki K, Kunida K, Biondini M, Hatzoglou A, Poullet P, Formstecher E, Yeaman C, Matsuda M, Rossé C, and Camonis J
- Subjects
- Animals, Down-Regulation, Enzyme Activation, GTPase-Activating Proteins genetics, GTPase-Activating Proteins metabolism, Gene Silencing, Microtubule-Organizing Center physiology, Microtubule-Organizing Center ultrastructure, Rats, Transcription Factors metabolism, Transcription Factors physiology, rac1 GTP-Binding Protein genetics, ral GTP-Binding Proteins genetics, ral GTP-Binding Proteins physiology, Cell Movement physiology, GTPase-Activating Proteins physiology, rac1 GTP-Binding Protein metabolism
- Abstract
The coordination of the several pathways involved in cell motility is poorly understood. Here, we identify SH3BP1, belonging to the RhoGAP family, as a partner of the exocyst complex and establish a physical and functional link between two motility-driving pathways, the Ral/exocyst and Rac signaling pathways. We show that SH3BP1 localizes together with the exocyst to the leading edge of motile cells and that SH3BP1 regulates cell migration via its GAP activity upon Rac1. SH3BP1 loss of function induces abnormally high Rac1 activity at the front, as visualized by in vivo biosensors, and disorganized and instable protrusions, as revealed by cell morphodynamics analysis. Consistently, constitutively active Rac1 mimics the phenotype of SH3BP1 depletion: slow migration and aberrant cell morphodynamics. Our finding that SH3BP1 downregulates Rac1 at the motile-cell front indicates that Rac1 inactivation in this location, as well as its activation by GEF proteins, is a fundamental requirement for cell motility., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF