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Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa
Rho-type GTPases are key regulators that control eukaryotic cell polarity, but their role in fungal morphogenesis is only beginning to emerge. In this study, we investigate the role of the CDC-42 – RAC – CDC-24 module in Neurospora crassa. rac and cdc-42 deletion mutants are viable, but generate hig...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3210136/ https://www.ncbi.nlm.nih.gov/pubmed/22087253 http://dx.doi.org/10.1371/journal.pone.0027148 |
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author | Araujo-Palomares, Cynthia L. Richthammer, Corinna Seiler, Stephan Castro-Longoria, Ernestina |
author_facet | Araujo-Palomares, Cynthia L. Richthammer, Corinna Seiler, Stephan Castro-Longoria, Ernestina |
author_sort | Araujo-Palomares, Cynthia L. |
collection | PubMed |
description | Rho-type GTPases are key regulators that control eukaryotic cell polarity, but their role in fungal morphogenesis is only beginning to emerge. In this study, we investigate the role of the CDC-42 – RAC – CDC-24 module in Neurospora crassa. rac and cdc-42 deletion mutants are viable, but generate highly compact colonies with severe morphological defects. Double mutants carrying conditional and loss of function alleles of rac and cdc-42 are lethal, indicating that both GTPases share at least one common essential function. The defects of the GTPase mutants are phenocopied by deletion and conditional alleles of the guanine exchange factor (GEF) cdc-24, and in vitro GDP-GTP exchange assays identify CDC-24 as specific GEF for both CDC-42 and RAC. In vivo confocal microscopy shows that this module is organized as membrane-associated cap that covers the hyphal apex. However, the specific localization patterns of the three proteins are distinct, indicating different functions of RAC and CDC-42 within the hyphal tip. CDC-42 localized as confined apical membrane-associated crescent, while RAC labeled a membrane-associated ring excluding the region labeled by CDC42. The GEF CDC-24 occupied a strategic position, localizing as broad apical membrane-associated crescent and in the apical cytosol excluding the Spitzenkörper. RAC and CDC-42 also display distinct localization patterns during branch initiation and germ tube formation, with CDC-42 accumulating at the plasma membrane before RAC. Together with the distinct cellular defects of rac and cdc-42 mutants, these localizations suggest that CDC-42 is more important for polarity establishment, while the primary function of RAC may be maintaining polarity. In summary, this study identifies CDC-24 as essential regulator for RAC and CDC-42 that have common and distinct functions during polarity establishment and maintenance of cell polarity in N. crassa. |
format | Online Article Text |
id | pubmed-3210136 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-32101362011-11-15 Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa Araujo-Palomares, Cynthia L. Richthammer, Corinna Seiler, Stephan Castro-Longoria, Ernestina PLoS One Research Article Rho-type GTPases are key regulators that control eukaryotic cell polarity, but their role in fungal morphogenesis is only beginning to emerge. In this study, we investigate the role of the CDC-42 – RAC – CDC-24 module in Neurospora crassa. rac and cdc-42 deletion mutants are viable, but generate highly compact colonies with severe morphological defects. Double mutants carrying conditional and loss of function alleles of rac and cdc-42 are lethal, indicating that both GTPases share at least one common essential function. The defects of the GTPase mutants are phenocopied by deletion and conditional alleles of the guanine exchange factor (GEF) cdc-24, and in vitro GDP-GTP exchange assays identify CDC-24 as specific GEF for both CDC-42 and RAC. In vivo confocal microscopy shows that this module is organized as membrane-associated cap that covers the hyphal apex. However, the specific localization patterns of the three proteins are distinct, indicating different functions of RAC and CDC-42 within the hyphal tip. CDC-42 localized as confined apical membrane-associated crescent, while RAC labeled a membrane-associated ring excluding the region labeled by CDC42. The GEF CDC-24 occupied a strategic position, localizing as broad apical membrane-associated crescent and in the apical cytosol excluding the Spitzenkörper. RAC and CDC-42 also display distinct localization patterns during branch initiation and germ tube formation, with CDC-42 accumulating at the plasma membrane before RAC. Together with the distinct cellular defects of rac and cdc-42 mutants, these localizations suggest that CDC-42 is more important for polarity establishment, while the primary function of RAC may be maintaining polarity. In summary, this study identifies CDC-24 as essential regulator for RAC and CDC-42 that have common and distinct functions during polarity establishment and maintenance of cell polarity in N. crassa. Public Library of Science 2011-11-07 /pmc/articles/PMC3210136/ /pubmed/22087253 http://dx.doi.org/10.1371/journal.pone.0027148 Text en Araujo-Palomares et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Araujo-Palomares, Cynthia L. Richthammer, Corinna Seiler, Stephan Castro-Longoria, Ernestina Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa |
title | Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa
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title_full | Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa
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title_fullStr | Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa
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title_full_unstemmed | Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa
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title_short | Functional Characterization and Cellular Dynamics of the CDC-42 – RAC – CDC-24 Module in Neurospora crassa
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title_sort | functional characterization and cellular dynamics of the cdc-42 – rac – cdc-24 module in neurospora crassa |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3210136/ https://www.ncbi.nlm.nih.gov/pubmed/22087253 http://dx.doi.org/10.1371/journal.pone.0027148 |
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