1
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Harrell M, Liu Z, Campbell BF, Chinsen O, Hong T, Das M. The Arp2/3 complex promotes periodic removal of Pak1-mediated negative feedback to facilitate anticorrelated Cdc42 oscillations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566261. [PMID: 38106068 PMCID: PMC10723479 DOI: 10.1101/2023.11.08.566261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The conserved GTPase Cdc42 is a major regulator of polarized growth in most eukaryotes. Cdc42 periodically cycles between active and inactive states at sites of polarized growth. These periodic cycles are caused by positive feedback and time-delayed negative feedback loops. In the bipolar yeast S. pombe, both growing ends must regulate Cdc42 activity. At each cell end, Cdc42 activity recruits the Pak1 kinase which prevents further Cdc42 activation thus establishing negative feedback. It is unclear how Cdc42 activation returns to the end after Pak1-dependent negative feedback. Using genetic and chemical perturbations, we find that disrupting branched actin-mediated endocytosis disables Cdc42 reactivation at the cell ends. With our experimental data and mathematical models, we show that endocytosis-dependent Pak1 removal from the cell ends allows the Cdc42 activator Scd1 to return to that end to enable reactivation of Cdc42. Moreover, we show that Pak1 elicits its own removal via activation of endocytosis. In agreement with these observations, our model and experimental data show that in each oscillatory cycle, Cdc42 activation increases followed by an increase in Pak1 recruitment at that end. These findings provide a deeper insight into the self-organization of Cdc42 regulation and reveal previously unknown feedback with endocytosis in the establishment of cell polarity.
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Affiliation(s)
- Marcus Harrell
- Biology Department, Boston College, Chestnut Hill, MA, 02467
| | - Ziyi Liu
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, TN, 37916
| | | | - Olivia Chinsen
- Biology Department, Boston College, Chestnut Hill, MA, 02467
| | - Tian Hong
- Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, TN, 37916
| | - Maitreyi Das
- Biology Department, Boston College, Chestnut Hill, MA, 02467
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2
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Ohtsuka H, Otsubo Y, Shimasaki T, Yamashita A, Aiba H. ecl family genes: Factors linking starvation and lifespan extension in Schizosaccharomyces pombe. Mol Microbiol 2023; 120:645-657. [PMID: 37525511 DOI: 10.1111/mmi.15134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
In the fission yeast Schizosaccharomyces pombe, the duration of survival in the stationary phase, termed the chronological lifespan (CLS), is affected by various environmental factors and the corresponding gene activities. The ecl family genes were identified in the genomic region encoding non-coding RNA as positive regulators of CLS in S. pombe, and subsequently shown to encode relatively short proteins. Several studies revealed that ecl family genes respond to various nutritional starvation conditions via different mechanisms, and they are additionally involved in stress resistance, autophagy, sexual differentiation, and cell cycle control. Recent studies reported that Ecl family proteins strongly suppress target of rapamycin complex 1, which is a conserved eukaryotic nutrient-sensing kinase complex that also regulates longevity in a variety of organisms. In this review, we introduce the regulatory mechanisms of Ecl family proteins and discuss their emerging findings.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Yoko Otsubo
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Akira Yamashita
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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3
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Cao M, Day AM, Galler M, Latimer HR, Byrne DP, Foy TW, Dwyer E, Bennett E, Palmer J, Morgan BA, Eyers PA, Veal EA. A peroxiredoxin-P38 MAPK scaffold increases MAPK activity by MAP3K-independent mechanisms. Mol Cell 2023; 83:3140-3154.e7. [PMID: 37572670 DOI: 10.1016/j.molcel.2023.07.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 05/19/2023] [Accepted: 07/14/2023] [Indexed: 08/14/2023]
Abstract
Peroxiredoxins (Prdxs) utilize reversibly oxidized cysteine residues to reduce peroxides and promote H2O2 signal transduction, including H2O2-induced activation of P38 MAPK. Prdxs form H2O2-induced disulfide complexes with many proteins, including multiple kinases involved in P38 MAPK signaling. Here, we show that a genetically encoded fusion between a Prdx and P38 MAPK is sufficient to hyperactivate the kinase in yeast and human cells by a mechanism that does not require the H2O2-sensing cysteine of the Prdx. We demonstrate that a P38-Prdx fusion protein compensates for loss of the yeast scaffold protein Mcs4 and MAP3K activity, driving yeast into mitosis. Based on our findings, we propose that the H2O2-induced formation of Prdx-MAPK disulfide complexes provides an alternative scaffold and signaling platform for MAPKK-MAPK signaling. The demonstration that formation of a complex with a Prdx is sufficient to modify the activity of a kinase has broad implications for peroxide-based signal transduction in eukaryotes.
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Affiliation(s)
- Min Cao
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Alison M Day
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Martin Galler
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Heather R Latimer
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Dominic P Byrne
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Thomas W Foy
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Emilia Dwyer
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Elise Bennett
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Jeremy Palmer
- Newcastle University Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Brian A Morgan
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Patrick A Eyers
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Elizabeth A Veal
- Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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4
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Kingma E, Diepeveen ET, Iñigo de la Cruz L, Laan L. Pleiotropy drives evolutionary repair of the responsiveness of polarized cell growth to environmental cues. Front Microbiol 2023; 14:1076570. [PMID: 37520345 PMCID: PMC10382278 DOI: 10.3389/fmicb.2023.1076570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 06/19/2023] [Indexed: 08/01/2023] Open
Abstract
The ability of cells to translate different extracellular cues into different intracellular responses is vital for their survival in unpredictable environments. In Saccharomyces cerevisiae, cell polarity is modulated in response to environmental signals which allows cells to adopt varying morphologies in different external conditions. The responsiveness of cell polarity to extracellular cues depends on the integration of the molecular network that regulates polarity establishment with networks that signal environmental changes. The coupling of molecular networks often leads to pleiotropic interactions that can make it difficult to determine whether the ability to respond to external signals emerges as an evolutionary response to environmental challenges or as a result of pleiotropic interactions between traits. Here, we study how the propensity of the polarity network of S. cerevisiae to evolve toward a state that is responsive to extracellular cues depends on the complexity of the environment. We show that the deletion of two genes, BEM3 and NRP1, disrupts the ability of the polarity network to respond to cues that signal the onset of the diauxic shift. By combining experimental evolution with whole-genome sequencing, we find that the restoration of the responsiveness to these cues correlates with mutations in genes involved in the sphingolipid synthesis pathway and that these mutations frequently settle in evolving populations irrespective of the complexity of the selective environment. We conclude that pleiotropic interactions make a significant contribution to the evolution of networks that are responsive to extracellular cues.
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5
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Salat-Canela C, Pérez P, Ayté J, Hidalgo E. Stress-induced cell depolarization through the MAP kinase-Cdc42 axis. Trends Cell Biol 2023; 33:124-137. [PMID: 35773059 DOI: 10.1016/j.tcb.2022.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/01/2022] [Accepted: 06/08/2022] [Indexed: 01/25/2023]
Abstract
General stress responses, which sense environmental or endogenous signals, aim at promoting cell survival and fitness during adverse conditions. In eukaryotes, mitogen-activated protein (MAP) kinase-driven cascades trigger a shift in the cell's gene expression program as a cellular adaptation to stress. Here, we review another aspect of activated MAP kinase cascades reported in fission yeast: the transient inhibition of cell polarity in response to oxidative stress. The phosphorylation by a stress-activated MAP kinase of regulators of the GTPase cell division cycle 42 (Cdc42) causes a transient inhibition of polarized cell growth. The formation of growth sites depends on limiting and essential polarity components. We summarize here some processes in which inhibition of Cdc42 may be a general mechanism to regulate polarized growth also under physiological conditions.
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Affiliation(s)
- Clàudia Salat-Canela
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, 37007 Salamanca, Spain
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003, Barcelona, Spain.
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Dr. Aiguader 88, 08003, Barcelona, Spain.
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6
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Zhang D, See T. Coordinated cortical ER remodeling facilitates actomyosin ring assembly. Curr Biol 2022; 32:2694-2703.e4. [DOI: 10.1016/j.cub.2022.04.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/24/2022] [Accepted: 04/27/2022] [Indexed: 11/15/2022]
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7
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Molines AT, Lemière J, Gazzola M, Steinmark IE, Edrington CH, Hsu CT, Real-Calderon P, Suhling K, Goshima G, Holt LJ, Thery M, Brouhard GJ, Chang F. Physical properties of the cytoplasm modulate the rates of microtubule polymerization and depolymerization. Dev Cell 2022; 57:466-479.e6. [PMID: 35231427 PMCID: PMC9319896 DOI: 10.1016/j.devcel.2022.02.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 11/01/2021] [Accepted: 01/31/2022] [Indexed: 11/20/2022]
Abstract
The cytoplasm is a crowded, visco-elastic environment whose physical properties change according to physiological or developmental states. How the physical properties of the cytoplasm impact cellular functions in vivo remains poorly understood. Here, we probe the effects of cytoplasmic concentration on microtubules by applying osmotic shifts to fission yeast, moss, and mammalian cells. We show that the rates of both microtubule polymerization and depolymerization scale linearly and inversely with cytoplasmic concentration; an increase in cytoplasmic concentration decreases the rates of microtubule polymerization and depolymerization proportionally, whereas a decrease in cytoplasmic concentration leads to the opposite. Numerous lines of evidence indicate that these effects are due to changes in cytoplasmic viscosity rather than cellular stress responses or macromolecular crowding per se. We reconstituted these effects on microtubules in vitro by tuning viscosity. Our findings indicate that, even in normal conditions, the viscosity of the cytoplasm modulates the reactions that underlie microtubule dynamic behaviors.
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Affiliation(s)
- Arthur T Molines
- Department of Cell and Tissue Biology, University of California, San Francisco, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA.
| | - Joël Lemière
- Department of Cell and Tissue Biology, University of California, San Francisco, USA
| | - Morgan Gazzola
- University of Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Phyiologie Cellulaire & Vegétale, CytoMorpho Lab, 38054 Grenoble, France
| | | | | | - Chieh-Ting Hsu
- Department of Physics, McGill University, Montréal, Quebec, Canada
| | - Paula Real-Calderon
- Department of Cell and Tissue Biology, University of California, San Francisco, USA
| | - Klaus Suhling
- Department of Physics, King's College London, London, UK
| | - Gohta Goshima
- Sugashima Marine Biological Laboratory and Division of Biological Science, Graduate School of Science, Nagoya University, Toba City, Mie, Japan; Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone Health, New York, NY 10016, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA
| | - Manuel Thery
- University of Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Phyiologie Cellulaire & Vegétale, CytoMorpho Lab, 38054 Grenoble, France; Université de Paris, INSERM, CEA, Institut de Recherche Saint Louis, U 976, CytoMorpho Lab, 75010 Paris, France
| | - Gary J Brouhard
- Department of Biology, McGill University, Montréal, Quebec, Canada
| | - Fred Chang
- Department of Cell and Tissue Biology, University of California, San Francisco, USA; Marine Biological Laboratory, Woods Hole, MA 02543, USA.
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8
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Salat-Canela C, Carmona M, Martín-García R, Pérez P, Ayté J, Hidalgo E. Stress-dependent inhibition of polarized cell growth through unbalancing the GEF/GAP regulation of Cdc42. Cell Rep 2021; 37:109951. [PMID: 34731607 DOI: 10.1016/j.celrep.2021.109951] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 07/20/2021] [Accepted: 10/14/2021] [Indexed: 10/19/2022] Open
Abstract
Cdc42 GTPase rules cell polarity and growth in fission yeast. It is negatively and positively regulated by GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs), respectively. Active Cdc42-GTP localizes to the poles, where it associates with numerous proteins constituting the polarity module. However, little is known about its downregulation. We describe here that oxidative stress causes Sty1-kinase-dependent Cdc42 inactivation at cell poles. Both the amount of active Cdc42 at tips and cell length inversely correlate with Sty1 activity, explaining the elongated morphology of Δsty1 cells. We have created stress-blinded cell poles either by eliminating two Cdc42 GAPs or through the constitutive tethering of Gef1 to cell tips, and we biochemically demonstrate that the GAPs Rga3/6 and the GEF Gef1 are direct substrates of Sty1. We propose that phosphorylation of Rga3/6 and Gef1 mediates the Sty1-dependent inhibition of Cdc42 at cell tips, halting polarized growth during stress adaptation.
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Affiliation(s)
- Clàudia Salat-Canela
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Mercè Carmona
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Rebeca Martín-García
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, 37007 Salamanca, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, 37007 Salamanca, Spain.
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain.
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, 08003 Barcelona, Spain.
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9
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Zhang Y, Wang X, Zhang Y, Liu Y, Wang D, Yu X, Wang H, Bai Z, Jiang YC, Li X, Zheng W, Li Q. Endothelial Cell Migration Regulated by Surface Topography of Poly(ε-caprolactone) Nanofibers. ACS Biomater Sci Eng 2021; 7:4959-4970. [PMID: 34543012 DOI: 10.1021/acsbiomaterials.1c00951] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The study of cell migration on biomaterials is of great significance in tissue engineering and regenerative medicine. In recent years, there has been increasing evidence that the physical properties of the extracellular matrix (ECM), such as surface topography, affect various cellular behaviors such as proliferation, adhesion, and migration. However, the biological mechanism of surface topography influencing cellular behavior is still unclear. In this study, we prepared polycaprolactone (PCL) fibrous materials with different surface microstructures by solvent casting, electrospinning, and self-induced crystallization. The corresponding topographical structure obtained is a two-dimensional (2D) flat surface, 2.5-dimensional (2.5D) fibers, and three-dimensional (3D) fibers with a multilevel microstructure. We then investigated the effects of the complex topographical structure on endothelial cell migration. Our study demonstrates that cells can sense the changes of micro- and nanomorphology on the surface of materials, adapt to the physical environment through biochemical reactions, and regulate actin polymerization and directional migration through Rac1 and Cdc42. The cells on the nanofibers are elongated spindles, and the positive feedback of cell adhesion and actin polymerization along the fiber direction makes the plasma membrane continue to protrude, promoting cell polarization and directional migration. This study might provide new insights into the biomaterial design, especially those used for artificial vascular grafts.
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Affiliation(s)
- Yang Zhang
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaofeng Wang
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Yan Zhang
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Yajing Liu
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Dongfang Wang
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Xueke Yu
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Haonan Wang
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Zhiyuan Bai
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Yong-Chao Jiang
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaomeng Li
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Wei Zheng
- Engineering and Technology Department, University of Wisconsin-STOUT, Menomonie, Wisconsin 54751, United States
| | - Qian Li
- School of Mechanics and Safety Engineering, National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou 450001, China
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10
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Rich-Robinson J, Russell A, Mancini E, Das M. Cdc42 reactivation at growth sites is regulated by local cell-cycle-dependent loss of its GTPase-activating protein Rga4 in fission yeast. J Cell Sci 2021; 134:272049. [PMID: 34523683 DOI: 10.1242/jcs.259291] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 12/18/2022] Open
Abstract
In fission yeast, polarized cell growth stops during division and resumes after cytokinesis completes and cells separate. It is unclear how growth reactivation is timed to occur immediately after cell separation. We uncoupled these sequential events by delaying cytokinesis with a temporary Latrunculin A treatment. Mitotic cells recovering from treatment initiate end growth during septation, displaying a polar elongation simultaneous with septation (PrESS) phenotype. PrESS cell ends reactivate Cdc42, a major regulator of polarized growth, during septation, but at a fixed time after anaphase B. A candidate screen implicates Rga4, a negative regulator of Cdc42, in this process. We show that Rga4 appears punctate at the cell sides during G2, but is diffuse during mitosis, extending to the ends. Although the Morphogenesis Orb6 (MOR) pathway is known to promote cell separation and growth by activating protein synthesis, we find that, for polarized growth, removal of Rga4 from the ends is also necessary. Therefore, we propose that growth resumes after division once the MOR pathway is activated and the ends lose Rga4 in a cell-cycle-dependent manner.
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Affiliation(s)
- Julie Rich-Robinson
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Afton Russell
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Eleanor Mancini
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Maitreyi Das
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
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11
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Gerganova V, Lamas I, Rutkowski DM, Vještica A, Castro DG, Vincenzetti V, Vavylonis D, Martin SG. Cell patterning by secretion-induced plasma membrane flows. SCIENCE ADVANCES 2021; 7:eabg6718. [PMID: 34533984 PMCID: PMC8448446 DOI: 10.1126/sciadv.abg6718] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/26/2021] [Indexed: 05/20/2023]
Abstract
Cells self-organize using reaction-diffusion and fluid-flow principles. Whether bulk membrane flows contribute to cell patterning has not been established. Here, using mathematical modeling, optogenetics, and synthetic probes, we show that polarized exocytosis causes lateral membrane flows away from regions of membrane insertion. Plasma membrane–associated proteins with sufficiently low diffusion and/or detachment rates couple to the flows and deplete from areas of exocytosis. In rod-shaped fission yeast cells, zones of Cdc42 GTPase activity driving polarized exocytosis are limited by GTPase activating proteins (GAPs). We show that membrane flows pattern the GAP Rga4 distribution and that coupling of a synthetic GAP to membrane flows is sufficient to establish the rod shape. Thus, membrane flows induced by Cdc42-dependent exocytosis form a negative feedback restricting the zone of Cdc42 activity.
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Affiliation(s)
- Veneta Gerganova
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Iker Lamas
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | | | - Aleksandar Vještica
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Daniela Gallo Castro
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Vincent Vincenzetti
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Dimitrios Vavylonis
- Department of Physics, Lehigh University, Bethlehem, PA 18015, USA
- Corresponding author. (S.G.M.); (D.V.)
| | - Sophie G. Martin
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
- Corresponding author. (S.G.M.); (D.V.)
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12
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Odermatt PD, Miettinen TP, Lemière J, Kang JH, Bostan E, Manalis SR, Huang KC, Chang F. Variations of intracellular density during the cell cycle arise from tip-growth regulation in fission yeast. eLife 2021; 10:64901. [PMID: 34100714 PMCID: PMC8221806 DOI: 10.7554/elife.64901] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 06/07/2021] [Indexed: 12/24/2022] Open
Abstract
Intracellular density impacts the physical nature of the cytoplasm and can globally affect cellular processes, yet density regulation remains poorly understood. Here, using a new quantitative phase imaging method, we determined that dry-mass density in fission yeast is maintained in a narrow distribution and exhibits homeostatic behavior. However, density varied during the cell cycle, decreasing during G2, increasing in mitosis and cytokinesis, and dropping rapidly at cell birth. These density variations were explained by a constant rate of biomass synthesis, coupled to slowdown of volume growth during cell division and rapid expansion post-cytokinesis. Arrest at specific cell-cycle stages exacerbated density changes. Spatially heterogeneous patterns of density suggested links between density regulation, tip growth, and intracellular osmotic pressure. Our results demonstrate that systematic density variations during the cell cycle are predominantly due to modulation of volume expansion, and reveal functional consequences of density gradients and cell-cycle arrests.
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Affiliation(s)
- Pascal D Odermatt
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States.,Department of Bioengineering, Stanford University, Stanford, United States
| | - Teemu P Miettinen
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,MRC Laboratory for Molecular Cell Biology, University College, London, United Kingdom
| | - Joël Lemière
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
| | - Joon Ho Kang
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,Department of Physics, Massachusetts Institute of Technology, Cambridge, United States.,Brain Science Institute, Korea Institute of Science and Technology, Seoul, Republic of Korea
| | - Emrah Bostan
- Informatics Institute, University of Amsterdam, Amsterdamn, Netherlands
| | - Scott R Manalis
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, United States.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States.,Chan Zuckerberg Biohub, San Francisco, United States
| | - Fred Chang
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, United States
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13
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Vicente-Soler J, Soto T, Franco A, Cansado J, Madrid M. The Multiple Functions of Rho GTPases in Fission Yeasts. Cells 2021; 10:1422. [PMID: 34200466 PMCID: PMC8228308 DOI: 10.3390/cells10061422] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/03/2021] [Accepted: 06/04/2021] [Indexed: 01/20/2023] Open
Abstract
The Rho family of GTPases represents highly conserved molecular switches involved in a plethora of physiological processes. Fission yeast Schizosaccharomyces pombe has become a fundamental model organism to study the functions of Rho GTPases over the past few decades. In recent years, another fission yeast species, Schizosaccharomyces japonicus, has come into focus offering insight into evolutionary changes within the genus. Both fission yeasts contain only six Rho-type GTPases that are spatiotemporally controlled by multiple guanine-nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs), and whose intricate regulation in response to external cues is starting to be uncovered. In the present review, we will outline and discuss the current knowledge and recent advances on how the fission yeasts Rho family GTPases regulate essential physiological processes such as morphogenesis and polarity, cellular integrity, cytokinesis and cellular differentiation.
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Affiliation(s)
| | | | | | - José Cansado
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.V.-S.); (T.S.); (A.F.)
| | - Marisa Madrid
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain; (J.V.-S.); (T.S.); (A.F.)
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14
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Moreno-Ruiz D, Salzmann L, Fricker MD, Zeilinger S, Lichius A. Stress-Activated Protein Kinase Signalling Regulates Mycoparasitic Hyphal-Hyphal Interactions in Trichoderma atroviride. J Fungi (Basel) 2021; 7:jof7050365. [PMID: 34066643 PMCID: PMC8148604 DOI: 10.3390/jof7050365] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 04/30/2021] [Accepted: 05/01/2021] [Indexed: 11/30/2022] Open
Abstract
Trichoderma atroviride is a mycoparasitic fungus used as biological control agent against fungal plant pathogens. The recognition and appropriate morphogenetic responses to prey-derived signals are essential for successful mycoparasitism. We established microcolony confrontation assays using T. atroviride strains expressing cell division cycle 42 (Cdc42) and Ras-related C3 botulinum toxin substrate 1 (Rac1) interactive binding (CRIB) reporters to analyse morphogenetic changes and the dynamic displacement of localized GTPase activity during polarized tip growth. Microscopic analyses showed that Trichoderma experiences significant polarity stress when approaching its fungal preys. The perception of prey-derived signals is integrated via the guanosine triphosphatase (GTPase) and mitogen-activated protein kinase (MAPK) signalling network, and deletion of the MAP kinases Trichoderma MAPK 1 (Tmk1) and Tmk3 affected T. atroviride tip polarization, chemotropic growth, and contact-induced morphogenesis so severely that the establishment of mycoparasitism was highly inefficient to impossible. The responses varied depending on the prey species and the interaction stage, reflecting the high selectivity of the signalling process. Our data suggest that Tmk3 affects the polarity-stress adaptation process especially during the pre-contact phase, whereas Tmk1 regulates contact-induced morphogenesis at the early-contact phase. Neither Tmk1 nor Tmk3 loss-of-function could be fully compensated within the GTPase/MAPK signalling network underscoring the crucial importance of a sensitive polarized tip growth apparatus for successful mycoparasitism.
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Affiliation(s)
- Dubraska Moreno-Ruiz
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria; (D.M.-R.); (L.S.); (S.Z.)
| | - Linda Salzmann
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria; (D.M.-R.); (L.S.); (S.Z.)
| | - Mark D. Fricker
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK;
| | - Susanne Zeilinger
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria; (D.M.-R.); (L.S.); (S.Z.)
| | - Alexander Lichius
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria; (D.M.-R.); (L.S.); (S.Z.)
- Correspondence:
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15
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Ashraf S, Tay YD, Kelly DA, Sawin KE. Microtubule-independent movement of the fission yeast nucleus. J Cell Sci 2021; 134:jcs.253021. [PMID: 33602740 PMCID: PMC8015250 DOI: 10.1242/jcs.253021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 02/09/2021] [Indexed: 12/14/2022] Open
Abstract
Movement of the cell nucleus typically involves the cytoskeleton and either polymerization-based pushing forces or motor-based pulling forces. In the fission yeast Schizosaccharomyces pombe, nuclear movement and positioning are thought to depend on microtubule polymerization-based pushing forces. Here, we describe a novel, microtubule-independent, form of nuclear movement in fission yeast. Microtubule-independent nuclear movement is directed towards growing cell tips, and it is strongest when the nucleus is close to a growing cell tip, and weakest when the nucleus is far from that tip. Microtubule-independent nuclear movement requires actin cables but does not depend on actin polymerization-based pushing or myosin V-based pulling forces. The vesicle-associated membrane protein (VAMP)-associated proteins (VAPs) Scs2 and Scs22, which are critical for endoplasmic reticulum-plasma membrane contact sites in fission yeast, are also required for microtubule-independent nuclear movement. We also find that in cells in which microtubule-based pushing forces are present, disruption of actin cables leads to increased fluctuations in interphase nuclear positioning and subsequent altered septation. Our results suggest two non-exclusive mechanisms for microtubule-independent nuclear movement, which may help illuminate aspects of nuclear positioning in other cells.
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16
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Ohtsuka H, Shimasaki T, Aiba H. Genes affecting the extension of chronological lifespan in Schizosaccharomyces pombe (fission yeast). Mol Microbiol 2020; 115:623-642. [PMID: 33064911 PMCID: PMC8246873 DOI: 10.1111/mmi.14627] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/17/2020] [Accepted: 10/11/2020] [Indexed: 02/06/2023]
Abstract
So far, more than 70 genes involved in the chronological lifespan (CLS) of Schizosaccharomyces pombe (fission yeast) have been reported. In this mini‐review, we arrange and summarize these genes based on the reported genetic interactions between them and the physical interactions between their products. We describe the signal transduction pathways that affect CLS in S. pombe: target of rapamycin complex 1, cAMP‐dependent protein kinase, Sty1, and Pmk1 pathways have important functions in the regulation of CLS extension. Furthermore, the Php transcription complex, Ecl1 family proteins, cyclin Clg1, and the cyclin‐dependent kinase Pef1 are important for the regulation of CLS extension in S. pombe. Most of the known genes involved in CLS extension are related to these pathways and genes. In this review, we focus on the individual genes regulating CLS extension in S. pombe and discuss the interactions among them.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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17
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Gómez-Gil E, Martín-García R, Vicente-Soler J, Franco A, Vázquez-Marín B, Prieto-Ruiz F, Soto T, Pérez P, Madrid M, Cansado J. Stress-activated MAPK signaling controls fission yeast actomyosin ring integrity by modulating formin For3 levels. eLife 2020; 9:57951. [PMID: 32915139 PMCID: PMC7511234 DOI: 10.7554/elife.57951] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 09/10/2020] [Indexed: 11/13/2022] Open
Abstract
Cytokinesis, which enables the physical separation of daughter cells once mitosis has been completed, is executed in fungal and animal cells by a contractile actin- and myosin-based ring (CAR). In the fission yeast Schizosaccharomyces pombe, the formin For3 nucleates actin cables and also co-operates for CAR assembly during cytokinesis. Mitogen-activated protein kinases (MAPKs) regulate essential adaptive responses in eukaryotic organisms to environmental changes. We show that the stress-activated protein kinase pathway (SAPK) and its effector, MAPK Sty1, downregulates CAR assembly in S. pombe when its integrity becomes compromised during cytoskeletal damage and stress by reducing For3 levels. Accurate control of For3 levels by the SAPK pathway may thus represent a novel regulatory mechanism of cytokinesis outcome in response to environmental cues. Conversely, SAPK signaling favors CAR assembly and integrity in its close relative Schizosaccharomyces japonicus, revealing a remarkable evolutionary divergence of this response within the fission yeast clade.
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Affiliation(s)
- Elisa Gómez-Gil
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Rebeca Martín-García
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Jero Vicente-Soler
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Alejandro Franco
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Beatriz Vázquez-Marín
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Francisco Prieto-Ruiz
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Teresa Soto
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica (IBFG), Consejo Superior de Investigaciones Científicas, Universidad de Salamanca, Salamanca, Spain
| | - Marisa Madrid
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Jose Cansado
- Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
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18
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Silva PM, Puerner C, Seminara A, Bassilana M, Arkowitz RA. Secretory Vesicle Clustering in Fungal Filamentous Cells Does Not Require Directional Growth. Cell Rep 2020; 28:2231-2245.e5. [PMID: 31433995 DOI: 10.1016/j.celrep.2019.07.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 04/22/2019] [Accepted: 07/18/2019] [Indexed: 11/27/2022] Open
Abstract
During symmetry breaking, the highly conserved Rho GTPase Cdc42 becomes stabilized at a defined site via an amplification process. However, little is known about how a new polarity site is established in an already asymmetric cell-a critical process in a changing environment. The human fungal pathogen Candida albicans switches from budding to filamentous growth in response to external cues, a transition controlled by Cdc42. Here, we have used optogenetic manipulation of cell polarity to reset growth in asymmetric filamentous C. albicans cells. We show that increasing the level of active Cdc42 on the plasma membrane results in disruption of the exocyst subunit Sec3 localization and a striking de novo clustering of secretory vesicles. This new cluster of secretory vesicles is highly dynamic, moving by hops and jumps, until a new growth site is established. Our results reveal that secretory vesicle clustering can occur in the absence of directional growth.
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Affiliation(s)
- Patrícia M Silva
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France
| | - Charles Puerner
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France
| | - Agnese Seminara
- Université Côte d'Azur, CNRS, Institute Physics of Nice (INPHYNI), Ave. J. Vallot, Nice, France
| | - Martine Bassilana
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France
| | - Robert A Arkowitz
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France.
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19
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Fission Yeast NDR/LATS Kinase Orb6 Regulates Exocytosis via Phosphorylation of the Exocyst Complex. Cell Rep 2020; 26:1654-1667.e7. [PMID: 30726745 PMCID: PMC6367570 DOI: 10.1016/j.celrep.2019.01.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 11/03/2018] [Accepted: 01/08/2019] [Indexed: 11/22/2022] Open
Abstract
NDR/LATS kinases regulate multiple aspects of cell polarity and morphogenesis from yeast to mammals. Fission yeast NDR/LATS kinase Orb6 has been proposed to control cell polarity by regulating the Cdc42 guanine nucleotide exchange factor Gef1. Here, we show that Orb6 regulates polarity largely independently of Gef1 and that Orb6 positively regulates exocytosis. Through Orb6 inhibition in vivo and quantitative global phosphoproteomics, we identify Orb6 targets, including proteins involved in membrane trafficking. We confirm Sec3 and Sec5, conserved components of the exocyst complex, as substrates of Orb6 both in vivo and in vitro, and we show that Orb6 kinase activity is important for exocyst localization to cell tips and for exocyst activity during septum dissolution after cytokinesis. We further find that Orb6 phosphorylation of Sec3 contributes to exocyst function in concert with exocyst protein Exo70. We propose that Orb6 contributes to polarized growth by regulating membrane trafficking at multiple levels. Inhibiting Orb6 leads to cessation of cell elongation and impaired exocytosis These and related phenotypes are independent of the Cdc42 GEF Gef1 Phosphoproteomics reveals multiple Orb6 targets involved in membrane trafficking Exocyst protein Sec3 is an important Orb6 substrate for daughter-cell separation
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20
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Wang Y, Gong J, Yao Y. Extracellular nanofiber-orchestrated cytoskeletal reorganization and mediated directional migration of cancer cells. NANOSCALE 2020; 12:3183-3193. [PMID: 31967158 DOI: 10.1039/c9nr10143h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Extracellular matrix anisotropy tunes the organization and movement of surrounding cells. The primary mediators of the extracellular matrix are fiber-based materials. Natural collagen fibers reorganize from curled and isotropic fibers to straightened and anisotropic fibers during tumorigenesis, yet how the cytoskeleton is involved in the directional migration in response to the topography is unknown. To investigate this, we fabricated random, orthogonal, and aligned nanofibers to deconstruct the basic mechanisms for the migration of the human pancreatic cancer cells PANC-1 on different substrates. We found that the extracellular matrix orchestrated actin reorganization by templating the surface topography as an irregular pattern on random fibers, crossover feature on orthogonal fibers, and parallel characteristics on aligned fibers. The intermediate filament as vimentin was upregulated to form a perinuclear shape on orthogonal or aligned surfaces. We also found that the nanofiber topography mediated the directional migration via different mechanisms. The directionality ratio and velocity were statistically analyzed to unveil the pattern of directional migration. Cells on aligned nanofibers yielded a greater velocity. Rac1 and Cdc42 were involved in cell migration through regulating actin polymerization and membrane protrusions. Thus, our findings elucidate that nanofiber alignment orchestrates cytoskeletal reorganization and mediates the directional migration of cancer cells.
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Affiliation(s)
- Yiqun Wang
- School of Physical Science and Technology, Shanghai Tech University, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China. and Shanghai Institute of Organic Chemistry, University of Chinese Academy of Science, 345 Lingling Road, Shanghai 200032, China
| | - Jinkang Gong
- School of Physical Science and Technology, Shanghai Tech University, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China.
| | - Yuan Yao
- School of Physical Science and Technology, Shanghai Tech University, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China.
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21
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Optogenetics reveals Cdc42 local activation by scaffold-mediated positive feedback and Ras GTPase. PLoS Biol 2020; 18:e3000600. [PMID: 31978045 PMCID: PMC7002011 DOI: 10.1371/journal.pbio.3000600] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 02/05/2020] [Accepted: 01/02/2020] [Indexed: 12/31/2022] Open
Abstract
Local activity of the small GTPase Cdc42 is critical for cell polarization. Whereas scaffold-mediated positive feedback was proposed to break symmetry of budding yeast cells and produce a single zone of Cdc42 activity, the existence of similar regulation has not been probed in other organisms. Here, we address this problem using rod-shaped cells of fission yeast Schizosaccharomyces pombe, which exhibit zones of active Cdc42-GTP at both cell poles. We implemented the CRY2-CIB1 optogenetic system for acute light-dependent protein recruitment to the plasma membrane, which allowed to directly demonstrate positive feedback. Indeed, optogenetic recruitment of constitutively active Cdc42 leads to co-recruitment of the guanine nucleotide exchange factor (GEF) Scd1 and endogenous Cdc42, in a manner dependent on the scaffold protein Scd2. We show that Scd2 function is dispensable when the positive feedback operates through an engineered interaction between the GEF and a Cdc42 effector, the p21-activated kinase 1 (Pak1). Remarkably, this rewired positive feedback confers viability and allows cells to form 2 zones of active Cdc42 even when otherwise essential Cdc42 activators are lacking. These cells further revealed that the small GTPase Ras1 plays a role in both localizing the GEF Scd1 and promoting its activity, which potentiates the positive feedback. We conclude that scaffold-mediated positive feedback, gated by Ras activity, confers robust polarization for rod-shape formation. The small GTPase Cdc42 is a key regulator of cell polarization. This study uses optogenetic and genetic strategies to show that Cdc42 is under positive feedback regulation potentiated by Ras GTPase activity.
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22
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RNA-Binding Protein Rnc1 Regulates Cell Length at Division and Acute Stress Response in Fission Yeast through Negative Feedback Modulation of the Stress-Activated Mitogen-Activated Protein Kinase Pathway. mBio 2020; 11:mBio.02815-19. [PMID: 31911490 PMCID: PMC6946801 DOI: 10.1128/mbio.02815-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Control of mRNA localization, stability, turnover, and translation by RNA-binding proteins (RBPs) influences essential processes in all eukaryotes, including signaling by mitogen-activated protein kinase (MAPK) pathways. We describe that in the fission yeast Schizosaccharomyces pombe the RBP Rnc1 negatively regulates cell length at division during unperturbed growth and recovery after acute stress by reducing the activity of the MAPK Sty1, which regulates cell growth and differentiation during environmental cues. This mechanism relies on Rnc1 binding to specific mRNAs encoding both enhancers and negative regulators of Sty1 activity. Remarkably, multiple phosphorylation of Rnc1 by Sty1 favors RBP binding and destabilization of the above mRNAs. Thus, posttranscriptional modulation of MAP kinase signaling by RNA-binding proteins emerges as a major regulatory mechanism that dictates the growth cycle and cellular adaptation in response to the changing environment in eukaryotic organisms. RNA-binding proteins (RBPs) play a major role during control of mRNA localization, stability, and translation and are central to most cellular processes. In the fission yeast Schizosaccharomyces pombe, the multiple K homology (KH) domain RBP Rnc1 downregulates the activity of the cell integrity pathway (CIP) via stabilization of pmp1+ mRNA, which encodes the Pmp1 phosphatase that inactivates Pmk1, the mitogen-activated protein kinase (MAPK) component of this signaling cascade. However, Rnc1 likely regulates the half-life/stability of additional mRNAs. We show that Rnc1 downregulates the activity of Sty1, the MAPK of the stress-activated MAPK pathway (SAPK), during control of cell length at division and recovery in response to acute stress. Importantly, this control strictly depends on Rnc1’s ability to bind mRNAs encoding activators (Wak1 MAPKKK, Wis1 MAPKK) and downregulators (Atf1 transcription factor, Pyp1 and Pyp2 phosphatases) of Sty1 phosphorylation through its KH domains. Moreover, Sty1 is responsible for Rnc1 phosphorylation in vivo at multiple phosphosites during growth and stress, and these modifications trigger Rnc1 for proper binding and destabilization of the above mRNA targets. Phosphorylation by Sty1 prompts Rnc1-dependent mRNA destabilization to negatively control SAPK signaling, thus revealing an additional feedback mechanism that allows precise tuning of MAPK activity during unperturbed cell growth and stress.
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23
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Hercyk BS, Rich-Robinson J, Mitoubsi AS, Harrell MA, Das ME. A novel interplay between GEFs orchestrates Cdc42 activity during cell polarity and cytokinesis in fission yeast. J Cell Sci 2019; 132:jcs.236018. [PMID: 31719163 DOI: 10.1242/jcs.229252/video-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/04/2019] [Indexed: 05/23/2023] Open
Abstract
Cdc42, a conserved regulator of cell polarity, is activated by two GEFs, Gef1 and Scd1, in fission yeast. Why the cell needs two GEFs is unclear, given that they are partially redundant and activate the same GTPase. Using the GEF localization pattern during cytokinesis as a paradigm, we report a novel interplay between Gef1 and Scd1 that spatially modulates Cdc42. We find that Gef1 promotes Scd1 localization to the division site during cytokinesis through recruitment of the scaffold protein Scd2, via a Cdc42 feedforward pathway. Similarly, during interphase Gef1 promotes Scd1 recruitment at the new end to enable the transition from monopolar to bipolar growth. Reciprocally, Scd1 restricts Gef1 localization to prevent ectopic Cdc42 activation during cytokinesis to promote cell separation, and to maintain cell shape during interphase. Our findings reveal an elegant regulatory pattern in which Gef1 primes Cdc42 activation at new sites to initiate Scd1-dependent polarized growth, while Scd1 restricts Gef1 to sites of polarization. We propose that crosstalk between GEFs is a conserved mechanism that orchestrates Cdc42 activation during complex cellular processes.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Brian S Hercyk
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Julie Rich-Robinson
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Ahmad S Mitoubsi
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Marcus A Harrell
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Maitreyi E Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
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24
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Hercyk BS, Rich-Robinson J, Mitoubsi AS, Harrell MA, Das ME. A novel interplay between GEFs orchestrates Cdc42 activity during cell polarity and cytokinesis in fission yeast. J Cell Sci 2019; 132:jcs.236018. [PMID: 31719163 DOI: 10.1242/jcs.236018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/04/2019] [Indexed: 12/12/2022] Open
Abstract
Cdc42, a conserved regulator of cell polarity, is activated by two GEFs, Gef1 and Scd1, in fission yeast. Why the cell needs two GEFs is unclear, given that they are partially redundant and activate the same GTPase. Using the GEF localization pattern during cytokinesis as a paradigm, we report a novel interplay between Gef1 and Scd1 that spatially modulates Cdc42. We find that Gef1 promotes Scd1 localization to the division site during cytokinesis through recruitment of the scaffold protein Scd2, via a Cdc42 feedforward pathway. Similarly, during interphase Gef1 promotes Scd1 recruitment at the new end to enable the transition from monopolar to bipolar growth. Reciprocally, Scd1 restricts Gef1 localization to prevent ectopic Cdc42 activation during cytokinesis to promote cell separation, and to maintain cell shape during interphase. Our findings reveal an elegant regulatory pattern in which Gef1 primes Cdc42 activation at new sites to initiate Scd1-dependent polarized growth, while Scd1 restricts Gef1 to sites of polarization. We propose that crosstalk between GEFs is a conserved mechanism that orchestrates Cdc42 activation during complex cellular processes.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Brian S Hercyk
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Julie Rich-Robinson
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Ahmad S Mitoubsi
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Marcus A Harrell
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
| | - Maitreyi E Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 7996-1939, USA
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25
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Knapp BD, Odermatt P, Rojas ER, Cheng W, He X, Huang KC, Chang F. Decoupling of Rates of Protein Synthesis from Cell Expansion Leads to Supergrowth. Cell Syst 2019; 9:434-445.e6. [PMID: 31706948 PMCID: PMC6911364 DOI: 10.1016/j.cels.2019.10.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 07/02/2019] [Accepted: 09/30/2019] [Indexed: 01/02/2023]
Abstract
Cell growth is a complex process in which cells synthesize cellular components while they increase in size. It is generally assumed that the rate of biosynthesis must somehow be coordinated with the rate of growth in order to maintain intracellular concentrations. However, little is known about potential feedback mechanisms that could achieve proteome homeostasis or the consequences when this homeostasis is perturbed. Here, we identify conditions in which fission yeast cells are prevented from volume expansion but nevertheless continue to synthesize biomass, leading to general accumulation of proteins and increased cytoplasmic density. Upon removal of these perturbations, this biomass accumulation drove cells to undergo a multi-generational period of "supergrowth" wherein rapid volume growth outpaced biosynthesis, returning proteome concentrations back to normal within hours. These findings demonstrate a mechanism for global proteome homeostasis based on modulation of volume growth and dilution.
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Affiliation(s)
- Benjamin D Knapp
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Biophysics Program, Stanford University, Stanford, CA 94305, USA
| | - Pascal Odermatt
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Enrique R Rojas
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wenpeng Cheng
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Xiangwei He
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Kerwyn Casey Huang
- Biophysics Program, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 941586, USA.
| | - Fred Chang
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA.
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Chen C, Rodriguez Pino M, Haller PR, Verde F. Conserved NDR/LATS kinase controls RAS GTPase activity to regulate cell growth and chronological lifespan. Mol Biol Cell 2019; 30:2598-2616. [PMID: 31390298 PMCID: PMC6740195 DOI: 10.1091/mbc.e19-03-0172] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Adaptation to the nutritional environment is critical for all cells. RAS GTPase is a highly conserved GTP-binding protein with crucial functions for cell growth and differentiation in response to environmental conditions. Here, we describe a novel mechanism connecting RAS GTPase to nutrient availability in fission yeast. We report that the conserved NDR/LATS kinase Orb6 responds to nutritional cues and regulates Ras1 GTPase activity. Orb6 increases the protein levels of an Ras1 GTPase activator, the guanine nucleotide exchange factor Efc25, by phosphorylating Sts5, a protein bound to efc25 mRNA. By manipulating the extent of Orb6-mediated Sts5 assembly into RNP granules, we can modulate Efc25 protein levels, Ras1 GTPase activity, and, as a result, cell growth and cell survival. Thus, we conclude that the Orb6-Sts5-Ras1 regulatory axis plays a crucial role in promoting cell adaptation, balancing the opposing demands of promoting cell growth and extending chronological lifespan.
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Affiliation(s)
- Chuan Chen
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Marbelys Rodriguez Pino
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Patrick Roman Haller
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Fulvia Verde
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136
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Gómez-Gil E, Franco A, Madrid M, Vázquez-Marín B, Gacto M, Fernández-Breis J, Vicente-Soler J, Soto T, Cansado J. Quorum sensing and stress-activated MAPK signaling repress yeast to hypha transition in the fission yeast Schizosaccharomyces japonicus. PLoS Genet 2019; 15:e1008192. [PMID: 31150379 PMCID: PMC6561576 DOI: 10.1371/journal.pgen.1008192] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 06/12/2019] [Accepted: 05/13/2019] [Indexed: 01/14/2023] Open
Abstract
Quorum sensing (QS), a mechanism of microbial communication dependent on cell density, governs developmental decisions in many bacteria and in some pathogenic and non-pathogenic fungi including yeasts. In these simple eukaryotes this response is mediated by the release into the growth medium of quorum-sensing molecules (QSMs) whose concentration increases proportionally to the population density. To date the occurrence of QS is restricted to a few yeast species. We show that a QS mediated by the aromatic alcohols phenylethanol and tryptophol represses the dimorphic yeast to hypha differentiation in the fission yeast S. japonicus in response to an increased population density. In addition, the stress activated MAPK pathway (SAPK), which controls cell cycle progression and adaptation to environmental changes in this organism, constitutively represses yeast to hypha differentiation both at transcriptional and post-translational levels. Moreover, deletion of its main effectors Sty1 MAPK and Atf1 transcription factor partially suppressed the QS-dependent block of hyphal development under inducing conditions. RNAseq analysis showed that the expression of nrg1+, which encodes a putative ortholog of the transcription factor Nrg1 that represses yeast to hypha dimorphism in C. albicans, is downregulated both by QS and the SAPK pathway. Remarkably, Nrg1 may act in S. japonicus as an activator of hyphal differentiation instead of being a repressor. S. japonicus emerges as an attractive and amenable model organism to explore the QS mechanisms that regulate cellular differentiation in fungi. Quorum sensing is a relevant mechanism of communication dependent on population density that controls cell development and pathogenesis in microorganisms including fungi. We describe a quorum sensing mediated by the release of aromatic alcohols in the growth medium that blocks hyphal development in the fission yeast Schizosaccharomyces japonicus. This is the first description of such a mechanism in the fission yeast lineage, and confirms its expansion along Ascomycota fungi. The stress-responsive pathway (SAPK), which regulates fungal growth and differentiation, limits hyphal growth in S. japonicus in a constitutive fashion, and nonfunctional SAPK mutants are partially insensitive to quorum sensing and able to form hyphae in high cell density cultures. Nrg1, an important factor that blocks hyphal development in the pathogen Candida albicans, activates hyphal growth in S. japonicus, and its expression is counteracted by both quorum sensing and the SAPK pathway. Nrg1 function may thus have diverged evolutionary in this organism from being a repressor to an activator of hyphal development. S. japonicus emerges as a suitable model organism to explore the intricate mechanisms regulating fungal differentiation.
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Affiliation(s)
- Elisa Gómez-Gil
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Alejandro Franco
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Marisa Madrid
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Beatriz Vázquez-Marín
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Mariano Gacto
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Jesualdo Fernández-Breis
- Departamento de Informática y Sistemas, Facultad de Informática. Universidad de Murcia, Murcia, Spain
| | - Jero Vicente-Soler
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
| | - Teresa Soto
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
- * E-mail: (TS); (JC)
| | - José Cansado
- Yeast Physiology Group, Departmento de Genética y Microbiología, Facultad de Biología. Universidad de Murcia, Murcia, Spain
- * E-mail: (TS); (JC)
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28
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Pérez P, Soto T, Gómez-Gil E, Cansado J. Functional interaction between Cdc42 and the stress MAPK signaling pathway during the regulation of fission yeast polarized growth. Int Microbiol 2019; 23:31-41. [PMID: 30989357 DOI: 10.1007/s10123-019-00072-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/18/2019] [Accepted: 03/20/2019] [Indexed: 12/12/2022]
Abstract
Cell polarization can be defined as the generation and maintenance of directional cellular organization. The spatial distribution and protein or lipid composition of the cell are not symmetric but organized in specialized domains which allow cells to grow and acquire a certain shape that is closely linked to their physiological function. The establishment and maintenance of polarized growth requires the coordination of diverse processes including cytoskeletal dynamics, membrane trafficking, and signaling cascade regulation. Some of the major players involved in the selection and maintenance of sites for polarized growth are Rho GTPases, which recognize the polarization site and transmit the signal to regulatory proteins of the cytoskeleton. Additionally, cytoskeletal organization, polarized secretion, and endocytosis are controlled by signaling pathways including those mediated by mitogen-activated protein kinases (MAPKs). Rho GTPases and the MAPK signaling pathways are strongly conserved from yeast to mammals, suggesting that the basic mechanisms of polarized growth have been maintained throughout evolution. For this reason, the study of how polarized growth is established and regulated in simple organisms such as the fission yeast Schizosaccharomyces pombe has contributed to broaden our knowledge about these processes in multicellular organisms. We review here the function of the Cdc42 GTPase and the stress activated MAPK (SAPK) signaling pathways during fission yeast polarized growth, and discuss the relevance of the crosstalk between both pathways.
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Affiliation(s)
- Pilar Pérez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas and Universidad de Salamanca, 37007, Salamanca, Spain.
| | - Teresa Soto
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Elisa Gómez-Gil
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain
| | - Jose Cansado
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain.
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29
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Daniels CN, Zyla TR, Lew DJ. A role for Gic1 and Gic2 in Cdc42 polarization at elevated temperature. PLoS One 2018; 13:e0200863. [PMID: 30566437 PMCID: PMC6300207 DOI: 10.1371/journal.pone.0200863] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/09/2018] [Indexed: 12/27/2022] Open
Abstract
The conserved Rho-family GTPase Cdc42 is a master regulator of polarity establishment in many cell types. Cdc42 becomes activated and concentrated in a region of the cell cortex, and recruits a variety of effector proteins to that site. In turn, many effectors participate in regulation of cytoskeletal elements in order to remodel the cytoskeleton in a polarized manner. The budding yeast Saccharomyces cerevisiae has served as a tractable model system for studies of cell polarity. In yeast cells, Cdc42 polarization involves a positive feedback loop in which effectors called p21-activated kinases (PAKs) act to recruit a Cdc42-directed guanine nucleotide exchange factor (GEF), generating more GTP-Cdc42 in areas that already have GTP-Cdc42. The GTPase-interacting components (GICs) Gic1 and Gic2 are also Cdc42 effectors, and have been implicated in regulation of the actin and septin cytoskeleton. However, we report that cells lacking GICs are primarily defective in polarizing Cdc42 itself, suggesting that they act upstream as well as downstream of Cdc42 in yeast. Our findings suggest that feedback pathways involving GTPase effectors may be more prevalent than had been appreciated.
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Affiliation(s)
- Christine N. Daniels
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America
| | - Trevin R. Zyla
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America
| | - Daniel J. Lew
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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30
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Haupt A, Ershov D, Minc N. A Positive Feedback between Growth and Polarity Provides Directional Persistency and Flexibility to the Process of Tip Growth. Curr Biol 2018; 28:3342-3351.e3. [DOI: 10.1016/j.cub.2018.09.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/24/2018] [Accepted: 09/11/2018] [Indexed: 12/12/2022]
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31
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Tay YD, Leda M, Goryachev AB, Sawin KE. Local and global Cdc42 guanine nucleotide exchange factors for fission yeast cell polarity are coordinated by microtubules and the Tea1-Tea4-Pom1 axis. J Cell Sci 2018; 131:jcs.216580. [PMID: 29930085 PMCID: PMC6080602 DOI: 10.1242/jcs.216580] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 06/14/2018] [Indexed: 12/30/2022] Open
Abstract
The conserved Rho-family GTPase Cdc42 plays a central role in eukaryotic cell polarity. The rod-shaped fission yeast Schizosaccharomyces pombe has two Cdc42 guanine nucleotide exchange factors (GEFs), Scd1 and Gef1, but little is known about how they are coordinated in polarized growth. Although the microtubule cytoskeleton is normally not required for polarity maintenance in fission yeast, we show here that when scd1 function is compromised, disruption of microtubules or the polarity landmark proteins Tea1, Tea4 or Pom1 leads to disruption of polarized growth. Instead, cells adopt an isotropic-like pattern of growth, which we term PORTLI growth. Surprisingly, PORTLI growth is caused by spatially inappropriate activity of Gef1. Although most Cdc42 GEFs are membrane associated, we find that Gef1 is a broadly distributed cytosolic protein rather than a membrane-associated protein at cell tips like Scd1. Microtubules and the Tea1–Tea4–Pom1 axis counteract inappropriate Gef1 activity by regulating the localization of the Cdc42 GTPase-activating protein Rga4. Our results suggest a new model of fission yeast cell polarity regulation, involving coordination of ‘local’ (Scd1) and ‘global’ (Gef1) Cdc42 GEFs via microtubules and microtubule-dependent polarity landmarks. Highlighted Article: Cell polarity in fission yeast is regulated by two different Cdc42 guanine nucleotide exchange factors, coordinated by the microtubule-dependent landmark system.
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Affiliation(s)
- Ye Dee Tay
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Marcin Leda
- SynthSys - Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, CH Waddington Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Andrew B Goryachev
- SynthSys - Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, CH Waddington Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kenneth E Sawin
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh EH9 3BF, UK
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32
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F-actin homeostasis through transcriptional regulation and proteasome-mediated proteolysis. Proc Natl Acad Sci U S A 2018; 115:E6487-E6496. [PMID: 29941587 DOI: 10.1073/pnas.1721935115] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Many organisms possess multiple and often divergent actins whose regulation and roles are not understood in detail. For example, Chlamydomonas reinhardtii has both a conventional actin (IDA5) and a highly divergent one (NAP1); only IDA5 is expressed in normal proliferating cells. We showed previously that the drug latrunculin B (LatB) causes loss of filamentous (F-) IDA5 and strong up-regulation of NAP1, which then provides essential actin function(s) by forming LatB-resistant F-NAP1. RNA-sequencing analyses now show that this up-regulation of NAP1 reflects a broad transcriptional response, much of which depends on three proteins (LAT1, LAT2, and LAT3) identified previously as essential for NAP1 transcription. Many of the LAT-regulated genes contain a putative cis-acting regulatory site, the "LRE motif." The LatB transcriptional program appears to be activated by loss of F-IDA5 and deactivated by formation of F-NAP1, thus forming an F-actin-dependent negative-feedback loop. Multiple genes encoding proteins of the ubiquitin-proteasome system are among those induced by LatB, resulting in rapid degradation of IDA5 (but not NAP1). Our results suggest that IDA5 degradation is functionally important because nonpolymerizable LatB-bound IDA5 interferes with the formation of F-NAP1. The genes for the actin-interacting proteins cofilin and profilin are also induced. Cofilin induction may further the clearance of IDA5 by promoting the scission of F-IDA5, whereas profilin appears to function in protecting monomeric IDA5 from degradation. This multifaceted regulatory system allows rapid and quantitative turnover of F-actin in response to cytoskeletal perturbations and probably also maintains F-actin homeostasis under normal growth conditions.
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33
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Hibi T, Ohtsuka H, Shimasaki T, Inui S, Shibuya M, Tatsukawa H, Kanie K, Yamamoto Y, Aiba H. Tschimganine and its derivatives extend the chronological life span of yeast via activation of the Sty1 pathway. Genes Cells 2018; 23:620-637. [PMID: 29900664 DOI: 10.1111/gtc.12604] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 05/01/2018] [Accepted: 05/15/2018] [Indexed: 12/13/2022]
Abstract
Most antiaging factors or life span extenders are associated with calorie restriction (CR). Very few of these factors function independently of, or additively with, CR. In this study, we focused on tschimganine, a compound that was reported to extend chronological life span (CLS). Although tschimganine led to the extension of CLS, it also inhibited yeast cell growth. We acquired a Schizosaccharomyces pombe mutant with a tolerance for tschimganine due to the gene crm1. The resulting Crm1 protein appears to export the stress-activated protein kinase Sty1 from the nucleus to the cytosol even under stressful conditions. Furthermore, we synthesized two derivative compounds of tschimganine, α-hibitakanine and β-hibitakanine; these derivatives did not inhibit cell growth, as seen with tschimganine. α-hibitakanine extended the CLS, not only in S. pombe but also in Saccharomyces cerevisiae, indicating the possibility that life span regulation by tschimganine derivative may be conserved across various yeast species. We found that the longevity induced by tschimganine was dependent on the Sty1 pathway. Based on our results, we propose that tschimganine and its derivatives extend CLS by activating the Sty1 pathway in fission yeast, and CR extends CLS via two distinct pathways, one Sty1-dependent and the other Sty1-independent. These findings provide the potential for creating an additive life span extension effect when combined with CR, as well as a better understanding of the mechanism of CLS.
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Affiliation(s)
- Takahide Hibi
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Shougo Inui
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Masatoshi Shibuya
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hideki Tatsukawa
- Laboratory of Cellular Biochemistry, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Kei Kanie
- Laboratory of Cell and Molecular Bioengineering, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Yoshihiko Yamamoto
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
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ER-PM Contacts Restrict Exocytic Sites for Polarized Morphogenesis. Curr Biol 2017; 28:146-153.e5. [PMID: 29290560 DOI: 10.1016/j.cub.2017.11.055] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/31/2017] [Accepted: 11/22/2017] [Indexed: 01/04/2023]
Abstract
Spatial control of exocytosis underlies polarized cell morphogenesis. In rod-shaped fission yeast, exocytic vesicles are conveyed along the actin cytoskeleton by myosin V motors toward growing cell ends [1, 2], the major sites for exocytosis. However, actomyosin-based vesicle delivery is dispensable for polarized secretion and cylindrical cell shape of fission yeast [3]. Thus, additional mechanisms should function in the spatial confinement of exocytosis. Here we report a novel role of endoplasmic reticulum (ER)-plasma membrane (PM) contacts in restricting exocytic sites for polarized fission yeast morphogenesis. We show that fission yeast cells deficient in both ER-PM contacts and actomyosin-based secretory vesicle transport display aberrant globular cell shape due to delocalized exocytosis. By artificially manipulating the strength and extent of ER-PM contacts in wild-type and mutant cells that exhibit induced ectopic exocytosis, we demonstrate that exocytosis and ER-PM contact formation are spatially incompatible. Furthermore, extensive ER-PM junctions at the non-growing lateral cell cortex prevent the PM from exocytic vesicle tethering and hence attenuate growth potential at cell sides. We thus propose that ER-PM contacts function as a new morphogenetic module by limiting exocytosis to growing cell tips in fission yeast. A similar mechanism could apply to other cell types with prominent ER-PM contacts.
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35
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Abstract
A conserved molecular machinery centered on the Cdc42 GTPase regulates cell polarity in diverse organisms. Here we review findings from budding and fission yeasts that reveal both a conserved core polarity circuit and several adaptations that each organism exploits to fulfill the needs of its lifestyle. The core circuit involves positive feedback by local activation of Cdc42 to generate a cluster of concentrated GTP-Cdc42 at the membrane. Species-specific pathways regulate the timing of polarization during the cell cycle, as well as the location and number of polarity sites.
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Affiliation(s)
- Jian-Geng Chiou
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710;
| | - Mohan K Balasubramanian
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Daniel J Lew
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710;
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36
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Goryachev AB, Leda M. Many roads to symmetry breaking: molecular mechanisms and theoretical models of yeast cell polarity. Mol Biol Cell 2017; 28:370-380. [PMID: 28137950 PMCID: PMC5341721 DOI: 10.1091/mbc.e16-10-0739] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 11/17/2016] [Accepted: 11/23/2016] [Indexed: 01/08/2023] Open
Abstract
Mathematical modeling has been instrumental in identifying common principles of cell polarity across diverse systems. These principles include positive feedback loops that are required to destabilize a spatially uniform state of the cell. The conserved small G-protein Cdc42 is a master regulator of eukaryotic cellular polarization. Here we discuss recent developments in studies of Cdc42 polarization in budding and fission yeasts and demonstrate that models describing symmetry-breaking polarization can be classified into six minimal classes based on the structure of positive feedback loops that activate and localize Cdc42. Owing to their generic system-independent nature, these model classes are also likely to be relevant for the G-protein–based symmetry-breaking systems of higher eukaryotes. We review experimental evidence pro et contra different theoretically plausible models and conclude that several parallel and non–mutually exclusive mechanisms are likely involved in cellular polarization of yeasts. This potential redundancy needs to be taken into consideration when interpreting the results of recent cell-rewiring studies.
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Affiliation(s)
- Andrew B Goryachev
- Center for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Marcin Leda
- Center for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
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37
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Opalko HE, Moseley JB. Dynamic regulation of Cdr1 kinase localization and phosphorylation during osmotic stress. J Biol Chem 2017; 292:18457-18468. [PMID: 28924043 DOI: 10.1074/jbc.m117.793034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 09/14/2017] [Indexed: 11/06/2022] Open
Abstract
Environmental conditions modulate cell cycle progression in many cell types. A key component of the eukaryotic cell cycle is the protein kinase Wee1, which inhibits the cyclin-dependent kinase Cdk1 in yeast through human cells. In the fission yeast Schizosaccharomyces pombe, the protein kinase Cdr1 is a mitotic inducer that promotes mitotic entry by phosphorylating and inhibiting Wee1. Cdr1 and Wee1 both localize to punctate structures, termed nodes, on the medial cortex, but it has been unknown whether node localization can be altered by physiological signals. Here we investigated how environmental conditions regulate Cdr1 signaling for cell division. Osmotic stress induced hyperphosphorylation of the mitotic inducer Cdr1 for several hours, and cells delayed division for the same time period. This stress-induced hyperphosphorylation required both Cdr1 autophosphorylation and the stress-activated protein kinase Sty1. During osmotic stress, Cdr1 exited cortical nodes and localized in the cytoplasm. Using a series of truncation mutants, we mapped a C-terminal domain that is necessary and sufficient for Cdr1 node localization and found that Sty1 directly phosphorylates this domain in vitro Sty1 was not required for Cdr1 exit from nodes, indicating the existence of additional regulatory signals. Both Cdr1 phosphorylation and node localization returned to basal levels when cells adapted to osmotic conditions and resumed cell cycle progression. In summary, we identified a mechanism that prevents Cdr1 colocalization with its inhibitory target Wee1 during osmotic stress. Dynamic regulation of protein localization to cortical nodes might represent a strategy to modulate entry into mitosis under differing environmental conditions.
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Affiliation(s)
- Hannah E Opalko
- From the Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - James B Moseley
- From the Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
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38
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Woods B, Lew DJ. Polarity establishment by Cdc42: Key roles for positive feedback and differential mobility. Small GTPases 2017; 10:130-137. [PMID: 28350208 DOI: 10.1080/21541248.2016.1275370] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Cell polarity is fundamental to the function of most cells. The evolutionarily conserved molecular machinery that controls cell polarity is centered on a family of GTPases related to Cdc42. Cdc42 becomes activated and concentrated at polarity sites, but studies in yeast model systems led to controversy on the mechanisms of polarization. Here we review recent studies that have clarified how Cdc42 becomes polarized in yeast. On one hand, findings that appeared to support a key role for the actin cytoskeleton and vesicle traffic in polarity establishment now appear to reflect the action of stress response pathways induced by cytoskeletal perturbations. On the other hand, new findings strongly support hypotheses on the polarization mechanism whose origins date back to the mathematician Alan Turing. The key features of the polarity establishment mechanism in yeasts include a positive feedback pathway in which active Cdc42 recruits a Cdc42 activator to polarity sites, and differential mobility of polarity "activators" and "substrates."
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Affiliation(s)
- Benjamin Woods
- a Department of Pharmacology and Cancer Biology , Duke University Medical Center , Durham , NC , USA
| | - Daniel J Lew
- a Department of Pharmacology and Cancer Biology , Duke University Medical Center , Durham , NC , USA
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