Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.

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 GTPas...

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Main Authors: Bita Khalili, Laura Merlini, Vincent Vincenzetti, Sophie G Martin, Dimitrios Vavylonis
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2018-07-01
Series:PLoS Computational Biology
Online Access:https://doi.org/10.1371/journal.pcbi.1006317
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author Bita Khalili
Laura Merlini
Vincent Vincenzetti
Sophie G Martin
Dimitrios Vavylonis
author_facet Bita Khalili
Laura Merlini
Vincent Vincenzetti
Sophie G Martin
Dimitrios Vavylonis
author_sort Bita Khalili
collection DOAJ
description 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.
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spelling doaj.art-932ed06d1fa54e798cbe63011eb84d672022-12-21T19:59:13ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582018-07-01147e100631710.1371/journal.pcbi.1006317Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.Bita KhaliliLaura MerliniVincent VincenzettiSophie G MartinDimitrios VavylonisIn 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.https://doi.org/10.1371/journal.pcbi.1006317
spellingShingle Bita Khalili
Laura Merlini
Vincent Vincenzetti
Sophie G Martin
Dimitrios Vavylonis
Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.
PLoS Computational Biology
title Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.
title_full Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.
title_fullStr Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.
title_full_unstemmed Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.
title_short Exploration and stabilization of Ras1 mating zone: A mechanism with positive and negative feedbacks.
title_sort exploration and stabilization of ras1 mating zone a mechanism with positive and negative feedbacks
url https://doi.org/10.1371/journal.pcbi.1006317
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