| Title: | Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks |
| Author(s): | Khalili B; Merlini L; Vincenzetti V; Martin SG; Vavylonis D; |
| Address: | "Department of Physics, Lehigh University, Bethlehem, Pennsylvania, United States of America. Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland" |
| DOI: | 10.1371/journal.pcbi.1006317 |
| ISSN/ISBN: | 1553-7358 (Electronic) 1553-734X (Print) 1553-734X (Linking) |
| Abstract: | "In mating fission yeast cells, sensing and response to extracellular pheromone concentrations occurs through an exploratory Cdc42 patch that stochastically samples the cell cortex before stabilizing towards a mating partner. Active Ras1 (Ras1-GTP), an upstream regulator of Cdc42, and Gap1, the GTPase-activating protein for Ras1, localize at the patch. We developed a reaction-diffusion model of Ras1 patch appearance and disappearance with a positive feedback by a Guanine nucleotide Exchange Factor (GEF) and Gap1 inhibition. The model is based on new estimates of Ras1-GDP, Ras1-GTP and Gap1 diffusion coefficients and rates of cytoplasmic exchange studied by FRAP. The model reproduces exploratory patch behavior and lack of Ras1 patch in cells lacking Gap1. Transition to a stable patch can occur by change of Gap1 rates constants or local increase of the positive feedback rate constants. The model predicts that the patch size and number of patches depend on the strength of positive and negative feedbacks. Measurements of Ras1 patch size and number in cells overexpressing the Ras1 GEF or Gap1 are consistent with the model" |
| Keywords: | "Actins/metabolism GTPase-Activating Proteins/metabolism Guanine Nucleotide Exchange Factors/metabolism Models, Biological Pheromones/metabolism Protein Binding Reproduction Schizosaccharomyces/enzymology/metabolism/*physiology Schizosaccharomyces pombe Pr;" |
| Notes: | "MedlineKhalili, Bita Merlini, Laura Vincenzetti, Vincent Martin, Sophie G Vavylonis, Dimitrios eng R01 GM098430/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't 2018/07/22 PLoS Comput Biol. 2018 Jul 20; 14(7):e1006317. doi: 10.1371/journal.pcbi.1006317. eCollection 2018 Jul" |
