| Title: | Differential GAP requirement for Cdc42-GTP polarization during proliferation and sexual reproduction |
| Author(s): | Gallo Castro D; Martin SG; |
| Address: | "Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland. Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland sophie.martin@unil.ch" |
| ISSN/ISBN: | 1540-8140 (Electronic) 0021-9525 (Print) 0021-9525 (Linking) |
| Abstract: | "The formation of a local zone of Cdc42 GTPase activity, which governs cell polarization in many cell types, requires not only local activation but also switch-off mechanisms. In this study, we identify Rga3, a paralog of Rga4, as a novel Cdc42 GTPase-activating protein (GAP) in the fission yeast Schizosaccharomyces pombe Contrary to Rga4, Rga3 localizes with Cdc42-GTP to sites of polarity. Rga3 is dispensable for cell polarization during mitotic growth, but it limits the lifetime of unstable Cdc42-GTP patches that underlie cell pairing during sexual reproduction, masking a partly compensatory patch-wandering motion. In consequence, cells lacking rga3 hyperpolarize and lose out in mating competition. Rga3 synergizes with the Cdc42 GAPs Rga4 and Rga6 to restrict Cdc42-GTP zone sizes during mitotic growth. Surprisingly, triple-mutant cells, which are almost fully round, retain pheromone-dependent dynamic polarization of Cdc42-GTP, extend a polarized projection, and mate. Thus, the requirement for Cdc42-GTP hydrolysis by GAPs is distinct during polarization by intrinsic or extrinsic cues" |
| Keywords: | GTPase-Activating Proteins/genetics/*metabolism Guanosine Triphosphate/genetics/*metabolism Mitosis/*physiology Schizosaccharomyces/*enzymology/genetics Schizosaccharomyces pombe Proteins/genetics/*metabolism cdc42 GTP-Binding Protein/genetics/*metabolism; |
| Notes: | "MedlineGallo Castro, Daniela Martin, Sophie G eng Research Support, Non-U.S. Gov't 2018/10/04 J Cell Biol. 2018 Dec 3; 217(12):4215-4229. doi: 10.1083/jcb.201806016. Epub 2018 Oct 2" |
