1
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Johnson CP, Shrestha S, Hart A, Jarvis KF, Genrich LE, Latario SG, Leclerc N, Systuk T, Scandura M, Geohegan RP, Khalil A, Kelley JB. Septin organization is regulated by the Gpa1 Ubiquitination Domain and Endocytic Machinery during the yeast pheromone response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2023.06.16.545321. [PMID: 37398119 PMCID: PMC10312744 DOI: 10.1101/2023.06.16.545321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The septin cytoskeleton plays a key role in the morphogenesis of the yeast mating projection, forming structures at the base of the projection. The yeast mating response uses the G-protein coupled receptor (GPCR), Ste2, to detect mating pheromone and initiate mating projection morphogenesis. Desensitization of the Gα, Gpa1, by the Regulator of G-protein Signaling (RGS), Sst2, is required for proper septin organization and morphogenesis. We hypothesized that Gpa1 would utilize known septin regulators to control septin organization. We found that single deletions of the septin chaperone Gic1, the Cdc42 GAP Bem3, and the endocytic adaptor proteins Ent1 and Ent2 rescued the polar cap accumulation of septins in the hyperactive Gα. We hypothesized that hyperactive Gα might increase the rate of endocytosis of a pheromone-responsive cargo, thereby altering where septins are localized. Mathematical modeling predicted that changes in endocytosis could explain the septin organizations we find in WT and mutant cells. Our results show that Gpa1-induced disorganization of septins requires clathrin-mediated endocytosis. Both the GPCR and the Gα are known to be internalized by clathrin-mediated endocytosis during the pheromone response. Deletion of the GPCR C-terminus to block internalization partially rescued septin organization. However, deleting the Gpa1 ubiquitination domain required for its endocytosis completely abrogated septin accumulation at the polarity site. Our data support a model where the location of endocytosis serves as a spatial mark for septin structure assembly and that desensitization of the Gα delays its endocytosis sufficiently that septins are placed peripheral to the site of Cdc42 polarity.
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Affiliation(s)
- Cory P. Johnson
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME
| | - Sudati Shrestha
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
| | - Andrew Hart
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
| | - Katherine F. Jarvis
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
- CompuMAINE Laboratory University of Maine, Orono, ME
| | - Loren E. Genrich
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
| | - Sarah G. Latario
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
| | - Nicholas Leclerc
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
| | - Tetiana Systuk
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
| | - Matthew Scandura
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
| | - Remi P. Geohegan
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME
| | - André Khalil
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME
- Department of Chemical and Biomedical Engineering, University of Maine, Orono, ME
- CompuMAINE Laboratory University of Maine, Orono, ME
| | - Joshua B. Kelley
- Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME
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2
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Ruan J, Yin Z, Yi P. Effects of fluorescent tags and activity status on the membrane localization of ROP GTPases. PLANT SIGNALING & BEHAVIOR 2024; 19:2306790. [PMID: 38270144 PMCID: PMC10813580 DOI: 10.1080/15592324.2024.2306790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 01/08/2024] [Indexed: 01/26/2024]
Abstract
Plant-specific Rho-type GTPases (ROPs) are master regulators of cell polarity and development. Over the past 30 years, their localization and dynamics have been largely examined with fluorescent proteins fused at the amino terminus without investigating their impact on protein function. The moss Physcomitrium patens genome encodes four rop genes. In this study, we introduce a fluorescent tag at the endogenous amino terminus of ROP4 in wild-type and rop1,2,3 triple mutant via homologous recombination and demonstrate that the fluorescent tag severely impairs ROP4 function and inhibits its localization on the plasma membrane. This phenotype is exacerbated in mutants lacking ROP-related GTPase-activating proteins. By comparing the localization of nonfunctional and functional ROP4 fusion reporters, we provide insight into the mechanism that governs the membrane association of ROPs.
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Affiliation(s)
- Jingtong Ruan
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Zihan Yin
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Peishan Yi
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, P. R. China
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3
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Wang ZJ, Thomson M. Localization of signaling receptors maximizes cellular information acquisition in spatially structured natural environments. Cell Syst 2022; 13:530-546.e12. [PMID: 35679857 DOI: 10.1016/j.cels.2022.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/08/2022] [Accepted: 05/12/2022] [Indexed: 01/25/2023]
Abstract
Cells in natural environments, such as tissue or soil, sense and respond to extracellular ligands with intricately structured and non-monotonic spatial distributions, sculpted by processes such as fluid flow and substrate adhesion. In this work, we show that spatial sensing and navigation can be optimized by adapting the spatial organization of signaling pathways to the spatial structure of the environment. We develop an information-theoretic framework for computing the optimal spatial organization of a sensing system for a given signaling environment. We find that receptor localization previously observed in cells maximizes information acquisition in simulated natural contexts, including tissue and soil. Specifically, information acquisition is maximized when receptors form localized patches at regions of maximal ligand concentration. Receptor localization extends naturally to produce a dynamic protocol for continuously redistributing signaling receptors, which when implemented using simple feedback, boosts cell navigation efficiency by 30-fold.
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Affiliation(s)
- Zitong Jerry Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Matt Thomson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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4
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Vaidžiulytė K, Macé AS, Battistella A, Beng W, Schauer K, Coppey M. Persistent cell migration emerges from a coupling between protrusion dynamics and polarized trafficking. eLife 2022; 11:69229. [PMID: 35302488 PMCID: PMC8963884 DOI: 10.7554/elife.69229] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 02/26/2022] [Indexed: 11/13/2022] Open
Abstract
Migrating cells present a variety of paths, from random to highly directional ones. While random movement can be explained by basal intrinsic activity, persistent movement requires stable polarization. Here, we quantitatively address emergence of persistent migration in (hTERT)–immortalizedRPE1 (retinal pigment epithelial) cells over long timescales. By live cell imaging and dynamic micropatterning, we demonstrate that the Nucleus-Golgi axis aligns with direction of migration leading to efficient cell movement. We show that polarized trafficking is directed toward protrusions with a 20-min delay, and that migration becomes random after disrupting internal cell organization. Eventually, we prove that localized optogenetic Cdc42 activation orients the Nucleus-Golgi axis. Our work suggests that polarized trafficking stabilizes the protrusive activity of the cell, while protrusive activity orients this polarity axis, leading to persistent cell migration. Using a minimal physical model, we show that this feedback is sufficient to recapitulate the quantitative properties of cell migration in the timescale of hours.
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Affiliation(s)
| | | | | | | | - Kristine Schauer
- Tumor Cell Dynamics Unit, Institut Gustave Roussy, Villejuif, France
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5
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Ghose D, Jacobs K, Ramirez S, Elston T, Lew D. Chemotactic movement of a polarity site enables yeast cells to find their mates. Proc Natl Acad Sci U S A 2021; 118:e2025445118. [PMID: 34050026 PMCID: PMC8179161 DOI: 10.1073/pnas.2025445118] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
How small eukaryotic cells can interpret dynamic, noisy, and spatially complex chemical gradients to orient growth or movement is poorly understood. We address this question using Saccharomyces cerevisiae, where cells orient polarity up pheromone gradients during mating. Initial orientation is often incorrect, but polarity sites then move around the cortex in a search for partners. We find that this movement is biased by local pheromone gradients across the polarity site: that is, movement of the polarity site is chemotactic. A bottom-up computational model recapitulates this biased movement. The model reveals how even though pheromone-bound receptors do not mimic the shape of external pheromone gradients, nonlinear and stochastic effects combine to generate effective gradient tracking. This mechanism for gradient tracking may be applicable to any cell that searches for a target in a complex chemical landscape.
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Affiliation(s)
- Debraj Ghose
- Computational Biology and Bioinformatics, Duke University, Durham, NC 27710
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Katherine Jacobs
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Samuel Ramirez
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Timothy Elston
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Daniel Lew
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710;
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6
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Duan X, Chen X, Wang K, Chen L, Glomb O, Johnsson N, Feng L, Zhou XQ, Bi E. Essential role of the endocytic site-associated protein Ecm25 in stress-induced cell elongation. Cell Rep 2021; 35:109122. [PMID: 34010635 PMCID: PMC8202958 DOI: 10.1016/j.celrep.2021.109122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 02/16/2021] [Accepted: 04/22/2021] [Indexed: 11/27/2022] Open
Abstract
How cells adopt a different morphology to cope with stress is not well understood. Here, we show that budding yeast Ecm25 associates with polarized endocytic sites and interacts with the polarity regulator Cdc42 and several late-stage endocytic proteins via distinct regions, including an actin filament-binding motif. Deletion of ECM25 does not affect Cdc42 activity or cause any strong defects in fluid-phase and clathrin-mediated endocytosis but completely abolishes hydroxyurea-induced cell elongation. This phenotype is accompanied by depolarization of the spatiotemporally coupled exo-endocytosis in the bud cortex while maintaining the overall mother-bud polarity. These data suggest that Ecm25 provides an essential link between the polarization signal and the endocytic machinery to enable adaptive morphogenesis under stress conditions. How cells adopt a different morphology to cope with stress is not well understood. Duan et al. report that the budding yeast protein Ecm25 plays an essential role in stress-induced cell elongation by linking the polarity regulator Cdc42 to the late-stage endocytic machinery.
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Affiliation(s)
- Xudong Duan
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA; Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130 Sichuan, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Xi Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Kangji Wang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Li Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Oliver Glomb
- Institut für Molekulare Genetik und Zellbiologie, Universität Ulm, 89081 Ulm, Germany
| | - Nils Johnsson
- Institut für Molekulare Genetik und Zellbiologie, Universität Ulm, 89081 Ulm, Germany
| | - Lin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130 Sichuan, China
| | - Xiao-Qiu Zhou
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130 Sichuan, China.
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA.
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7
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Lin DW, Liu Y, Lee YQ, Yang PJ, Ho CT, Hong JC, Hsiao JC, Liao DC, Liang AJ, Hung TC, Chen YC, Tu HL, Hsu CP, Huang HC. Construction of intracellular asymmetry and asymmetric division in Escherichia coli. Nat Commun 2021; 12:888. [PMID: 33563962 PMCID: PMC7873278 DOI: 10.1038/s41467-021-21135-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 01/09/2021] [Indexed: 01/23/2023] Open
Abstract
The design principle of establishing an intracellular protein gradient for asymmetric cell division is a long-standing fundamental question. While the major molecular players and their interactions have been elucidated via genetic approaches, the diversity and redundancy of natural systems complicate the extraction of critical underlying features. Here, we take a synthetic cell biology approach to construct intracellular asymmetry and asymmetric division in Escherichia coli, in which division is normally symmetric. We demonstrate that the oligomeric PopZ from Caulobacter crescentus can serve as a robust polarized scaffold to functionalize RNA polymerase. Furthermore, by using another oligomeric pole-targeting DivIVA from Bacillus subtilis, the newly synthesized protein can be constrained to further establish intracellular asymmetry, leading to asymmetric division and differentiation. Our findings suggest that the coupled oligomerization and restriction in diffusion may be a strategy for generating a spatial gradient for asymmetric cell division.
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Affiliation(s)
- Da-Wei Lin
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yang Liu
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yue-Qi Lee
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Po-Jiun Yang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Chia-Tse Ho
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Jui-Chung Hong
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | | | - Der-Chien Liao
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - An-Jou Liang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Tzu-Chiao Hung
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Yu-Chuan Chen
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan
| | - Chao-Ping Hsu
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan
| | - Hsiao-Chun Huang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.
- Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan.
- Department of Life Science, National Taiwan University, Taipei, Taiwan.
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan.
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8
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Banavar SP, Trogdon M, Drawert B, Yi TM, Petzold LR, Campàs O. Coordinating cell polarization and morphogenesis through mechanical feedback. PLoS Comput Biol 2021; 17:e1007971. [PMID: 33507956 PMCID: PMC7872284 DOI: 10.1371/journal.pcbi.1007971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 02/09/2021] [Accepted: 12/21/2020] [Indexed: 12/30/2022] Open
Abstract
Many cellular processes require cell polarization to be maintained as the cell changes shape, grows or moves. Without feedback mechanisms relaying information about cell shape to the polarity molecular machinery, the coordination between cell polarization and morphogenesis, movement or growth would not be possible. Here we theoretically and computationally study the role of a genetically-encoded mechanical feedback (in the Cell Wall Integrity pathway) as a potential coordination mechanism between cell morphogenesis and polarity during budding yeast mating projection growth. We developed a coarse-grained continuum description of the coupled dynamics of cell polarization and morphogenesis as well as 3D stochastic simulations of the molecular polarization machinery in the evolving cell shape. Both theoretical approaches show that in the absence of mechanical feedback (or in the presence of weak feedback), cell polarity cannot be maintained at the projection tip during growth, with the polarization cap wandering off the projection tip, arresting morphogenesis. In contrast, for mechanical feedback strengths above a threshold, cells can robustly maintain cell polarization at the tip and simultaneously sustain mating projection growth. These results indicate that the mechanical feedback encoded in the Cell Wall Integrity pathway can provide important positional information to the molecular machinery in the cell, thereby enabling the coordination of cell polarization and morphogenesis.
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Affiliation(s)
- Samhita P. Banavar
- Department of Physics, University of California, University of California, Santa Barbara, California, United States of America
- California NanoSystems Institute, University of California, Santa Barbara, California, United States of America
| | - Michael Trogdon
- Department of Mechanical Engineering, University of California, Santa Barbara, California, United States of America
| | - Brian Drawert
- Department of Computer Science, University of North Carolina, Asheville, North Carolina, United States of America
| | - Tau-Mu Yi
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, California, United States of America
| | - Linda R. Petzold
- Department of Mechanical Engineering, University of California, Santa Barbara, California, United States of America
- Center for Bioengineering, University of California, Santa Barbara, California, United States of America
| | - Otger Campàs
- California NanoSystems Institute, University of California, Santa Barbara, California, United States of America
- Department of Mechanical Engineering, University of California, Santa Barbara, California, United States of America
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, California, United States of America
- Center for Bioengineering, University of California, Santa Barbara, California, United States of America
- Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany
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9
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Kopfer KH, Jäger W, Matthäus F. A mechanochemical model for rho GTPase mediated cell polarization. J Theor Biol 2020; 504:110386. [DOI: 10.1016/j.jtbi.2020.110386] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 06/15/2020] [Accepted: 06/17/2020] [Indexed: 01/13/2023]
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10
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Cheng Y, Felix B, Othmer HG. The Roles of Signaling in Cytoskeletal Changes, Random Movement, Direction-Sensing and Polarization of Eukaryotic Cells. Cells 2020; 9:E1437. [PMID: 32531876 PMCID: PMC7348768 DOI: 10.3390/cells9061437] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 12/21/2022] Open
Abstract
Movement of cells and tissues is essential at various stages during the lifetime of an organism, including morphogenesis in early development, in the immune response to pathogens, and during wound-healing and tissue regeneration. Individual cells are able to move in a variety of microenvironments (MEs) (A glossary of the acronyms used herein is given at the end) by suitably adapting both their shape and how they transmit force to the ME, but how cells translate environmental signals into the forces that shape them and enable them to move is poorly understood. While many of the networks involved in signal detection, transduction and movement have been characterized, how intracellular signals control re-building of the cyctoskeleton to enable movement is not understood. In this review we discuss recent advances in our understanding of signal transduction networks related to direction-sensing and movement, and some of the problems that remain to be solved.
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Affiliation(s)
- Yougan Cheng
- Bristol Myers Squibb, Route 206 & Province Line Road, Princeton, NJ 08543, USA;
| | - Bryan Felix
- School of Mathematics, University of Minnesota, Minneapolis, MN 55445, USA;
| | - Hans G. Othmer
- School of Mathematics, University of Minnesota, Minneapolis, MN 55445, USA;
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11
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Abstract
The Rho GTPase Cdc42 is a central regulator of cell polarity in diverse cell types. The activity of Cdc42 is dynamically controlled in time and space to enable distinct polarization events, which generally occur along a single axis in response to spatial cues. Our understanding of the mechanisms underlying Cdc42 polarization has benefited largely from studies of the budding yeast Saccharomyces cerevisiae, a genetically tractable model organism. In budding yeast, Cdc42 activation occurs in two temporal steps in the G1 phase of the cell cycle to establish a proper growth site. Here, we review findings in budding yeast that reveal an intricate crosstalk among polarity proteins for biphasic Cdc42 regulation. The first step of Cdc42 activation may determine the axis of cell polarity, while the second step ensures robust Cdc42 polarization for growth. Biphasic Cdc42 polarization is likely to ensure the proper timing of events including the assembly and recognition of spatial landmarks and stepwise assembly of a new ring of septins, cytoskeletal GTP-binding proteins, at the incipient bud site. Biphasic activation of GTPases has also been observed in mammalian cells, suggesting that biphasic activation could be a general mechanism for signal-responsive cell polarization. Cdc42 activity is necessary for polarity establishment during normal cell division and development, but its activity has also been implicated in the promotion of aging. We also discuss negative polarity signaling and emerging concepts of Cdc42 signaling in cellular aging.
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Affiliation(s)
- Kristi E Miller
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.,Present address: Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Pil Jung Kang
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Hay-Oak Park
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
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12
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Ghose D, Lew D. Mechanistic insights into actin-driven polarity site movement in yeast. Mol Biol Cell 2020; 31:1085-1102. [PMID: 32186970 PMCID: PMC7346724 DOI: 10.1091/mbc.e20-01-0040] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/02/2020] [Accepted: 03/10/2020] [Indexed: 11/11/2022] Open
Abstract
Directed cell growth or migration are critical for the development and function of many eukaryotic cells. These cells develop a dynamic "front" (also called "polarity site") that can change direction. Polarity establishment involves autocatalytic accumulation of polarity regulators, including the conserved Rho-family GTPase Cdc42, but the mechanisms underlying polarity reorientation remain poorly understood. The tractable model yeast, Saccharomyces cerevisiae, relocates its polarity site when searching for mating partners. Relocation requires polymerized actin, and is thought to involve actin-mediated vesicle traffic to the polarity site. In this study, we provide a quantitative characterization of spontaneous polarity site movement as a search process and use a mechanistic computational model that combines polarity protein biochemical interactions with vesicle trafficking to probe how various processes might affect polarity site movement. Our findings identify two previously documented features of yeast vesicle traffic as being particularly relevant to such movement: tight spatial focusing of exocytosis enhances the directional persistence of movement, and association of Cdc42-directed GTPase-Activating Proteins with secretory vesicles increases the distance moved. Furthermore, we suggest that variation in the rate of exocytosis beyond simple Poisson dynamics may be needed to fully account for the characteristics of polarity site movement in vivo.
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Affiliation(s)
- Debraj Ghose
- Computational Biology and Bioinformatics, Duke University Medical Center, Durham, NC 27710
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Daniel Lew
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
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13
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Moran KD, Lew DJ. How Diffusion Impacts Cortical Protein Distribution in Yeasts. Cells 2020; 9:cells9051113. [PMID: 32365827 PMCID: PMC7291136 DOI: 10.3390/cells9051113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 12/11/2022] Open
Abstract
Proteins associated with the yeast plasma membrane often accumulate asymmetrically within the plane of the membrane. Asymmetric accumulation is thought to underlie diverse processes, including polarized growth, stress sensing, and aging. Here, we review our evolving understanding of how cells achieve asymmetric distributions of membrane proteins despite the anticipated dissipative effects of diffusion, and highlight recent findings suggesting that differential diffusion is exploited to create, rather than dissipate, asymmetry. We also highlight open questions about diffusion in yeast plasma membranes that remain unsolved.
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14
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Zhao L, Rehmani MS, Wang H. Exocytosis and Endocytosis: Yin-Yang Crosstalk for Sculpting a Dynamic Growing Pollen Tube Tip. FRONTIERS IN PLANT SCIENCE 2020; 11:572848. [PMID: 33123182 PMCID: PMC7573165 DOI: 10.3389/fpls.2020.572848] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/15/2020] [Indexed: 05/18/2023]
Abstract
The growing pollen tube has become one of the most fascinating model cell systems for investigations into cell polarity and polar cell growth in plants. Rapidly growing pollen tubes achieve tip-focused cell expansion by vigorous anterograde exocytosis, through which various newly synthesized macromolecules are directionally transported and deposited at the cell apex. Meanwhile, active retrograde endocytosis counter balances the exocytosis at the tip which is believed to recycle the excessive exocytic components for multiple rounds of secretion. Therefore, apical exocytosis and endocytosis are the frontline cellular processes which drive the polar growth of pollen tubes, although they represent opposite vesicular trafficking events with distinct underpinning mechanisms. Nevertheless, the molecular basis governing the spatiotemporal crosstalk and counterbalance of exocytosis and endocytosis during pollen tube polarization and growth remains elusive. Here we discuss recent insight into exocytosis and endocytosis in sculpturing high rates of polarized pollen tube growth. In addition, we especially introduce the novel integration of mathematical modeling in uncovering the mysteries of cell polarity and polar cell growth.
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15
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Vaidžiulytė K, Coppey M, Schauer K. Intracellular organization in cell polarity - placing organelles into the polarity loop. J Cell Sci 2019; 132:132/24/jcs230995. [PMID: 31836687 DOI: 10.1242/jcs.230995] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Many studies have investigated the processes that support polarity establishment and maintenance in cells. On the one hand, polarity complexes at the cell cortex and their downstream signaling pathways have been assigned as major regulators of polarity. On the other hand, intracellular organelles and their polarized trafficking routes have emerged as important components of polarity. In this Review, we argue that rather than trying to identify the prime 'culprit', now it is time to consider all these players as a collective. We highlight that understanding the intimate coordination between the polarized cell cortex and the intracellular compass that is defined by organelle positioning is essential to capture the concept of polarity. After briefly reviewing how polarity emerges from a dynamic maintenance of cellular asymmetries, we highlight how intracellular organelles and their associated trafficking routes provide diverse feedback for dynamic cell polarity maintenance. We argue that the asymmetric organelle compass is an indispensable element of the polarity network.
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Affiliation(s)
- Kotryna Vaidžiulytė
- Cell Biology and Cancer Unit, Institut Curie, PSL Research University, Sorbonne Université, CNRS, Paris 75005, France.,Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, Sorbonne Université, CNRS, Paris 75005, France.,Faculty of Science and Engineering, Sorbonne Université, Paris 75005, France
| | - Mathieu Coppey
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, Sorbonne Université, CNRS, Paris 75005, France
| | - Kristine Schauer
- Cell Biology and Cancer Unit, Institut Curie, PSL Research University, Sorbonne Université, CNRS, Paris 75005, France
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16
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Shadkhoo S, Mani M. The role of intracellular interactions in the collective polarization of tissues and its interplay with cellular geometry. PLoS Comput Biol 2019; 15:e1007454. [PMID: 31770364 PMCID: PMC6903760 DOI: 10.1371/journal.pcbi.1007454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/10/2019] [Accepted: 10/01/2019] [Indexed: 11/18/2022] Open
Abstract
Planar cell polarity (PCP), the long-range in-plane polarization of epithelial tissues, provides directional information that guides a multitude of developmental processes at cellular and tissue levels. While it is manifest that cells utilize both intracellular and intercellular interactions, the coupling between the two modules, essential to the coordination of collective polarization, remains an active area of investigation. We propose a generalized reaction-diffusion model to study the role of intracellular interactions in the emergence of long-range polarization, and show that the nonlocality of cytoplasmic interactions, i.e. coupling of membrane proteins localized on different cell-cell junctions, is of vital importance to the faithful detection of weak directional signals, and becomes increasingly more crucial to the stability of polarization against the deleterious effects of large geometric irregularities. We demonstrate that nonlocal interactions are necessary for geometric information to become accessible to the PCP components. The prediction of the model regarding polarization in elongated tissues, is shown to be in agreement with experimental observations, where the polarity emerges perpendicular to the axis of elongation. Core PCP is adopted as a model pathway, in term of which we interpret the model parameters. To this end, we introduce three distinct classes of mutations, (I) in membrane proteins, (II) in cytoplasmic proteins, and (III) local enhancement of geometric disorder. Comparing the in silico and in vivo phenotypes, we show that our model successfully recapitulates the salient phenotypic features of these mutations. Exploring the parameter space helps us shed light on the role of cytoplasmic proteins in cell-cell communications, and make falsifiable predictions regarding the cooperation of cytoplasmic and membrane proteins in the establishment of long-range polarization. Planar cell polarity (PCP) is an indispensable and conserved pathway in morphogenesis. In spite of the advances in understanding the different modules of PCP, a comprehensive picture of the intracellular protein-protein interactions necessary for the emergence of long-range tissue polarity is still lacking. In order to address this question, we devised a generalized reaction-diffusion model, through which we investigated the role of cytoplasmic interactions in PCP pathways. The length scale of intracellular interactions is demonstrated to be crucial to the stability of the cytoplasmic segregation of membrane proteins in disordered tissues, as well as the capacity of polarization field for detecting the gradient and geometrical cues. Finally, three classes of mutants are investigated within the context of our model. Comparison with the in vivo observations allows us to infer the major contributions of cytoplasmic proteins to the emergence of tissue polarity, and make testable predictions regarding the cooperation of cytoplasmic and membrane proteins in the coordination of collective polarization.
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Affiliation(s)
- Shahriar Shadkhoo
- Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California, United States of America.,Physics Department, University of California, Santa Barbara, California, United States of America
| | - Madhav Mani
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, Illinois, United States of America.,NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, Illinois, United States of America.,Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
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17
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Halatek J, Brauns F, Frey E. Self-organization principles of intracellular pattern formation. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0107. [PMID: 29632261 PMCID: PMC5904295 DOI: 10.1098/rstb.2017.0107] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2018] [Indexed: 11/13/2022] Open
Abstract
Dynamic patterning of specific proteins is essential for the spatio-temporal regulation of many important intracellular processes in prokaryotes, eukaryotes and multicellular organisms. The emergence of patterns generated by interactions of diffusing proteins is a paradigmatic example for self-organization. In this article, we review quantitative models for intracellular Min protein patterns in Escherichia coli, Cdc42 polarization in Saccharomyces cerevisiae and the bipolar PAR protein patterns found in Caenorhabditis elegans. By analysing the molecular processes driving these systems we derive a theoretical perspective on general principles underlying self-organized pattern formation. We argue that intracellular pattern formation is not captured by concepts such as ‘activators’, ‘inhibitors’ or ‘substrate depletion’. Instead, intracellular pattern formation is based on the redistribution of proteins by cytosolic diffusion, and the cycling of proteins between distinct conformational states. Therefore, mass-conserving reaction–diffusion equations provide the most appropriate framework to study intracellular pattern formation. We conclude that directed transport, e.g. cytosolic diffusion along an actively maintained cytosolic gradient, is the key process underlying pattern formation. Thus the basic principle of self-organization is the establishment and maintenance of directed transport by intracellular protein dynamics. This article is part of the theme issue ‘Self-organization in cell biology’.
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Affiliation(s)
- J Halatek
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, Theresienstraße 37, D-80333 München, Germany
| | - F Brauns
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, Theresienstraße 37, D-80333 München, Germany
| | - E Frey
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, Theresienstraße 37, D-80333 München, Germany
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18
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Abstract
Fluorescence recovery after photobleaching (FRAP) is an important tool used by cell biologists to study the diffusion and binding kinetics of vesicles, proteins, and other molecules in the cytoplasm, nucleus, or cell membrane. Although many FRAP models have been developed over the past decades, the influence of the complex boundaries of 3D cellular geometries on the recovery curves, in conjunction with regions of interest and optical effects (imaging, photobleaching, photoswitching, and scanning), has not been well studied. Here, we developed a 3D computational model of the FRAP process that incorporates particle diffusion, cell boundary effects, and the optical properties of the scanning confocal microscope, and validated this model using the tip-growing cells of Physcomitrella patens. We then show how these cell boundary and optical effects confound the interpretation of FRAP recovery curves, including the number of dynamic states of a given fluorophore, in a wide range of cellular geometries-both in two and three dimensions-namely nuclei, filopodia, and lamellipodia of mammalian cells, and in cell types such as the budding yeast, Saccharomyces pombe, and tip-growing plant cells. We explored the performance of existing analytical and algorithmic FRAP models in these various cellular geometries, and determined that the VCell VirtualFRAP tool provides the best accuracy to measure diffusion coefficients. Our computational model is not limited only to these cells types, but can easily be extended to other cellular geometries via the graphical Java-based application we also provide. This particle-based simulation-called the Digital Confocal Microscopy Suite or DCMS-can also perform fluorescence dynamics assays, such as number and brightness, fluorescence correlation spectroscopy, and raster image correlation spectroscopy, and could help shape the way these techniques are interpreted.
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19
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Kang PJ, Miller KE, Guegueniat J, Beven L, Park HO. The shared role of the Rsr1 GTPase and Gic1/Gic2 in Cdc42 polarization. Mol Biol Cell 2018; 29:2359-2369. [PMID: 30091649 PMCID: PMC6233053 DOI: 10.1091/mbc.e18-02-0145] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The Cdc42 GTPase plays a central role in polarity development in many species. In budding yeast, Cdc42 is essential for polarized growth at the proper site and also for spontaneous cell polarization in the absence of spatial cues. Cdc42 polarization is critical for multiple events in the G1 phase prior to bud emergence, including bud-site assembly, polarization of the actin cytoskeleton, and septin filament assembly to form a ring at the new bud site. Yet the mechanism by which Cdc42 polarizes is not fully understood. Here we report that biphasic Cdc42 polarization in the G1 phase is coupled to stepwise assembly of the septin ring for bud emergence. We show that the Rsr1 GTPase shares a partially redundant role with Gic1 and Gic2, two related Cdc42 effectors, in the first phase of Cdc42 polarization in haploid cells. We propose that the first phase of Cdc42 polarization is mediated by positive feedback loops that function in parallel-one involving Rsr1 via local activation of Cdc42 in response to spatial cues and another involving Gic1 or Gic2 via reduction of diffusion of active Cdc42.
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Affiliation(s)
- Pil Jung Kang
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Kristi E Miller
- Molecular Cellular Developmental Biology Program, The Ohio State University, Columbus, OH 43210
| | - Julia Guegueniat
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Laure Beven
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Hay-Oak Park
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.,Molecular Cellular Developmental Biology Program, The Ohio State University, Columbus, OH 43210
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20
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Tan X, Luo M, Liu AP. Clathrin-mediated endocytosis regulates fMLP-mediated neutrophil polarization. Heliyon 2018; 4:e00819. [PMID: 30263974 PMCID: PMC6157066 DOI: 10.1016/j.heliyon.2018.e00819] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/30/2018] [Accepted: 09/20/2018] [Indexed: 11/19/2022] Open
Abstract
A cell's ability to establish polarization is one of the key steps in directional migration. Upon the addition of a chemoattractant, N-formylmethionyl-leucyl-phenylalanine (fMLP), neutrophils rapidly develop a front end marked by a wide and dense actin network which is a feature of cell polarization. Despite a general understanding of bi-directional crosstalk between endocytosis and polarization, it remains unclear how clathrin-mediated endocytosis (CME) induced by chemoattractant binding to formyl peptide receptor (FPR) affects neutrophil polarization. In this work, we characterized the spatial organization of FPR and clathrin-coated pits (CCPs), the functional unit of CME, with and without fMLP and found that fMLP induced different distributions of FPR and CCPs. We further found that cells had impaired polarization induced by fMLP when CME is inhibited by small molecule inhibitors. Under these conditions, pERK, pAkt308, and pAkt473 were all severely blocked or had altered dynamics. The spatial organization between actin and two major clathrin-mediated endocytic proteins, clathrin and β-arrestin, were distinct and supported clathrin and β-arrestin's functional roles in mediating neutrophil polarization. Together these results suggest that CME plays a pivotal role in a complex process such as cell polarization.
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Affiliation(s)
- Xinyu Tan
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States
| | - Mingzhi Luo
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States
- Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, PR China
| | - Allen P. Liu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States
- Biophysics Program, University of Michigan, Ann Arbor, Michigan, United States
- Corresponding author.
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21
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Li H, Luo N, Wang W, Liu Z, Chen J, Zhao L, Tan L, Wang C, Qin Y, Li C, Xu T, Yang Z. The REN4 rheostat dynamically coordinates the apical and lateral domains of Arabidopsis pollen tubes. Nat Commun 2018; 9:2573. [PMID: 29968705 PMCID: PMC6030205 DOI: 10.1038/s41467-018-04838-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 05/11/2018] [Indexed: 11/08/2022] Open
Abstract
The dynamic maintenance of polar domains in the plasma membrane (PM) is critical for many fundamental processes, e.g., polar cell growth and growth guidance but remains poorly characterized. Rapid tip growth of Arabidopsis pollen tubes requires dynamic distribution of active ROP1 GTPase to the apical domain. Here, we show that clathrin-mediated endocytosis (CME) coordinates lateral REN4 with apical ROP1 signaling. REN4 interacted with but antagonized active ROP1. REN4 also interacts and co-localizes with CME components, but exhibits an opposite role to CME, which removes both REN4 and active ROP1 from the PM. Mathematical modeling shows that REN4 restrains the spatial distribution of active ROP1 and is important for the robustness of polarity control. Hence our results indicate that REN4 acts as a spatiotemporal rheostat by interacting with ROP1 to initiate their removal from the PM by CME, thereby coordinating a dynamic demarcation between apical and lateral domains during rapid tip growth.
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Affiliation(s)
- Hui Li
- Shanghai Center for Plant Stress Biology and Shanghai Institute of Plant Physiology and Ecolog, Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, 201602, Shanghai, China
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, CA, 92508, USA
- School of Life Sciences, East China Normal University, 200241, Shanghai, China
| | - Nan Luo
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, CA, 92508, USA
- FAFU-UCR Joint Center for Horticultural Biology and Metebolomics, Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002, Fuzhou, China
| | - Weidong Wang
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, CA, 92508, USA
| | - Zengyu Liu
- FAFU-UCR Joint Center for Horticultural Biology and Metebolomics, Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002, Fuzhou, China
| | - Jisheng Chen
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, CA, 92508, USA
- FAFU-UCR Joint Center for Horticultural Biology and Metebolomics, Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002, Fuzhou, China
| | - Liangtao Zhao
- Shanghai Center for Plant Stress Biology and Shanghai Institute of Plant Physiology and Ecolog, Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, 201602, Shanghai, China
| | - Li Tan
- Shanghai Center for Plant Stress Biology and Shanghai Institute of Plant Physiology and Ecolog, Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, 201602, Shanghai, China
| | - Chunyan Wang
- Shanghai Center for Plant Stress Biology and Shanghai Institute of Plant Physiology and Ecolog, Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, 201602, Shanghai, China
| | - Yuan Qin
- FAFU-UCR Joint Center for Horticultural Biology and Metebolomics, Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002, Fuzhou, China
| | - Chao Li
- School of Life Sciences, East China Normal University, 200241, Shanghai, China
| | - Tongda Xu
- Shanghai Center for Plant Stress Biology and Shanghai Institute of Plant Physiology and Ecolog, Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, 201602, Shanghai, China
- FAFU-UCR Joint Center for Horticultural Biology and Metebolomics, Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002, Fuzhou, China
| | - Zhenbiao Yang
- Center for Plant Cell Biology, Institute of Integrative Genome Biology, and Department of Botany and Plant Sciences, University of California, Riverside, CA, 92508, USA.
- FAFU-UCR Joint Center for Horticultural Biology and Metebolomics, Institute of Science and Technology, Fujian Agriculture and Forestry University, 350002, Fuzhou, China.
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22
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Riquelme M, Aguirre J, Bartnicki-García S, Braus GH, Feldbrügge M, Fleig U, Hansberg W, Herrera-Estrella A, Kämper J, Kück U, Mouriño-Pérez RR, Takeshita N, Fischer R. Fungal Morphogenesis, from the Polarized Growth of Hyphae to Complex Reproduction and Infection Structures. Microbiol Mol Biol Rev 2018; 82:e00068-17. [PMID: 29643171 PMCID: PMC5968459 DOI: 10.1128/mmbr.00068-17] [Citation(s) in RCA: 211] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Filamentous fungi constitute a large group of eukaryotic microorganisms that grow by forming simple tube-like hyphae that are capable of differentiating into more-complex morphological structures and distinct cell types. Hyphae form filamentous networks by extending at their tips while branching in subapical regions. Rapid tip elongation requires massive membrane insertion and extension of the rigid chitin-containing cell wall. This process is sustained by a continuous flow of secretory vesicles that depends on the coordinated action of the microtubule and actin cytoskeletons and the corresponding motors and associated proteins. Vesicles transport cell wall-synthesizing enzymes and accumulate in a special structure, the Spitzenkörper, before traveling further and fusing with the tip membrane. The place of vesicle fusion and growth direction are enabled and defined by the position of the Spitzenkörper, the so-called cell end markers, and other proteins involved in the exocytic process. Also important for tip extension is membrane recycling by endocytosis via early endosomes, which function as multipurpose transport vehicles for mRNA, septins, ribosomes, and peroxisomes. Cell integrity, hyphal branching, and morphogenesis are all processes that are largely dependent on vesicle and cytoskeleton dynamics. When hyphae differentiate structures for asexual or sexual reproduction or to mediate interspecies interactions, the hyphal basic cellular machinery may be reprogrammed through the synthesis of new proteins and/or the modification of protein activity. Although some transcriptional networks involved in such reprogramming of hyphae are well studied in several model filamentous fungi, clear connections between these networks and known determinants of hyphal morphogenesis are yet to be established.
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Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Jesús Aguirre
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Salomon Bartnicki-García
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Michael Feldbrügge
- Institute for Microbiology, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Ursula Fleig
- Institute for Functional Genomics of Microorganisms, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Wilhelm Hansberg
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Irapuato, Mexico
| | - Jörg Kämper
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Ulrich Kück
- Ruhr University Bochum, Lehrstuhl für Allgemeine und Molekulare Botanik, Bochum, Germany
| | - Rosa R Mouriño-Pérez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Norio Takeshita
- University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Japan
| | - Reinhard Fischer
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
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23
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Sartorel E, Ünlü C, Jose M, Massoni-Laporte A, Meca J, Sibarita JB, McCusker D. Phosphatidylserine and GTPase activation control Cdc42 nanoclustering to counter dissipative diffusion. Mol Biol Cell 2018; 29:1299-1310. [PMID: 29668348 PMCID: PMC5994902 DOI: 10.1091/mbc.e18-01-0051] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The anisotropic organization of plasma membrane constituents is indicative of mechanisms that drive the membrane away from equilibrium. However, defining these mechanisms is challenging due to the short spatiotemporal scales at which diffusion operates. Here, we use high-density single protein tracking combined with photoactivation localization microscopy (sptPALM) to monitor Cdc42 in budding yeast, a system in which Cdc42 exhibits anisotropic organization. Cdc42 exhibited reduced mobility at the cell pole, where it was organized in nanoclusters. The Cdc42 nanoclusters were larger at the cell pole than those observed elsewhere in the cell. These features were exacerbated in cells expressing Cdc42-GTP, and were dependent on the scaffold Bem1, which contributed to the range of mobility and nanocluster size exhibited by Cdc42. The lipid environment, in particular phosphatidylserine levels, also played a role in regulating Cdc42 nanoclustering. These studies reveal how the mobility of a Rho GTPase is controlled to counter the depletive effects of diffusion, thus stabilizing Cdc42 on the plasma membrane and sustaining cell polarity.
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Affiliation(s)
- Elodie Sartorel
- Université Bordeaux, CNRS, UMR 5095, European Institute of Chemistry and Biology, Pessac 33607, France
| | - Caner Ünlü
- Université Bordeaux, CNRS, UMR 5095, European Institute of Chemistry and Biology, Pessac 33607, France
| | - Mini Jose
- Université Bordeaux, CNRS, UMR 5095, European Institute of Chemistry and Biology, Pessac 33607, France
| | - Aurélie Massoni-Laporte
- Université Bordeaux, CNRS, UMR 5095, European Institute of Chemistry and Biology, Pessac 33607, France
| | - Julien Meca
- Université Bordeaux, CNRS, UMR 5095, European Institute of Chemistry and Biology, Pessac 33607, France
| | - Jean-Baptiste Sibarita
- Université Bordeaux, Institut Interdisciplinaire de Neurosciences, Bordeaux 33077, France.,CNRS UMR 5297, Institut Interdisciplinaire de Neurosciences, Bordeaux 33077, France
| | - Derek McCusker
- Université Bordeaux, CNRS, UMR 5095, European Institute of Chemistry and Biology, Pessac 33607, France
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24
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Giese W, Milicic G, Schröder A, Klipp E. Spatial modeling of the membrane-cytosolic interface in protein kinase signal transduction. PLoS Comput Biol 2018; 14:e1006075. [PMID: 29630597 PMCID: PMC5908195 DOI: 10.1371/journal.pcbi.1006075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 04/19/2018] [Accepted: 03/07/2018] [Indexed: 02/06/2023] Open
Abstract
The spatial architecture of signaling pathways and the interaction with cell size and morphology are complex, but little understood. With the advances of single cell imaging and single cell biology, it becomes crucial to understand intracellular processes in time and space. Activation of cell surface receptors often triggers a signaling cascade including the activation of membrane-attached and cytosolic signaling components, which eventually transmit the signal to the cell nucleus. Signaling proteins can form steep gradients in the cytosol, which cause strong cell size dependence. We show that the kinetics at the membrane-cytosolic interface and the ratio of cell membrane area to the enclosed cytosolic volume change the behavior of signaling cascades significantly. We suggest an estimate of average concentration for arbitrary cell shapes depending on the cell volume and cell surface area. The normalized variance, known from image analysis, is suggested as an alternative measure to quantify the deviation from the average concentration. A mathematical analysis of signal transduction in time and space is presented, providing analytical solutions for different spatial arrangements of linear signaling cascades. Quantification of signaling time scales reveals that signal propagation is faster at the membrane than at the nucleus, while this time difference decreases with the number of signaling components in the cytosol. Our investigations are complemented by numerical simulations of non-linear cascades with feedback and asymmetric cell shapes. We conclude that intracellular signal propagation is highly dependent on cell geometry and, thereby, conveys information on cell size and shape to the nucleus.
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Affiliation(s)
- Wolfgang Giese
- Mathematical Cell Physiology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Gregor Milicic
- Department of Mathematics, University of Salzburg, Salzburg, Austria
| | - Andreas Schröder
- Department of Mathematics, University of Salzburg, Salzburg, Austria
| | - Edda Klipp
- Theoretische Biophysik, Humboldt-Universität zu Berlin, Berlin, Germany
- * E-mail:
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25
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Hernández-González M, Bravo-Plaza I, Pinar M, de los Ríos V, Arst HN, Peñalva MA. Endocytic recycling via the TGN underlies the polarized hyphal mode of life. PLoS Genet 2018; 14:e1007291. [PMID: 29608571 PMCID: PMC5880334 DOI: 10.1371/journal.pgen.1007291] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/06/2018] [Indexed: 12/13/2022] Open
Abstract
Intracellular traffic in Aspergillus nidulans hyphae must cope with the challenges that the high rates of apical extension (1μm/min) and the long intracellular distances (>100 μm) impose. Understanding the ways in which the hyphal tip cell coordinates traffic to meet these challenges is of basic importance, but is also of considerable applied interest, as fungal invasiveness of animals and plants depends critically upon maintaining these high rates of growth. Rapid apical extension requires localization of cell-wall-modifying enzymes to hyphal tips. By combining genetic blocks in different trafficking steps with multidimensional epifluorescence microscopy and quantitative image analyses we demonstrate that polarization of the essential chitin-synthase ChsB occurs by indirect endocytic recycling, involving delivery/exocytosis to apices followed by internalization by the sub-apical endocytic collar of actin patches and subsequent trafficking to TGN cisternae, where it accumulates for ~1 min before being re-delivered to the apex by a RAB11/TRAPPII-dependent pathway. Accordingly, ChsB is stranded at the TGN by Sec7 inactivation but re-polarizes to the apical dome if the block is bypassed by a mutation in geaAgea1 that restores growth in the absence of Sec7. That polarization is independent of RAB5, that ChsB predominates at apex-proximal cisternae, and that upon dynein impairment ChsB is stalled at the tips in an aggregated endosome indicate that endocytosed ChsB traffics to the TGN via sorting endosomes functionally located upstream of the RAB5 domain and that this step requires dynein-mediated basipetal transport. It also requires RAB6 and its effector GARP (Vps51/Vps52/Vps53/Vps54), whose composition we determined by MS/MS following affinity chromatography purification. Ablation of any GARP component diverts ChsB to vacuoles and impairs growth and morphology markedly, emphasizing the important physiological role played by this pathway that, we propose, is central to the hyphal mode of growth. Filamentous fungi form long tubular cells, called hyphae, which grow rapidly by apical extension, enabling these sessile organisms to explore substrates and facilitating tissue invasion in the case of pathogenic species. Because the shape of the hyphae is determined by an external cell wall, hyphal growth requires that cell-wall sculpting enzymes polarize to the tips. Endocytosis is essential for hyphal growth, and it was suspected that this results from its participation in a recycling pathway that takes up cell-wall enzymes from the plasma membrane and re-delivers them to the apex. Here we track the trafficking of a chitin synthase (a cell-wall modifying enzyme) to demonstrate that it is polarized by endocytic recycling. This chitin synthase is delivered by exocytosis to the apex, but diffuses away until being captured by a subapical collar of actin patches (sites of endocytosis) from where it reaches a sorting endosome before undergoing transport to the nearest trans-Golgi cisternae and incorporating into secretory vesicles that re-deliver the enzyme to the apex. Because impairing transit across this pathway compromises apical extension markedly and results in severe morphological defects, the pathway could be manipulated to prevent fungal pathogenicity of plants and humans, an enormous burden on human welfare.
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Affiliation(s)
- Miguel Hernández-González
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Ignacio Bravo-Plaza
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Mario Pinar
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Vivian de los Ríos
- Proteomics Facility, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
| | - Herbert N. Arst
- Section of Microbiology, Imperial College London, Flowers Building, Armstrong Road, London, United Kingdom
| | - Miguel A. Peñalva
- Department of Cellular and Molecular Biology and Intradepartmental WhiteBiotech Unit, Centro de Investigaciones Biológicas del Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, Madrid, Spain
- * E-mail:
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26
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Spatial Cytoskeleton Organization Supports Targeted Intracellular Transport. Biophys J 2018; 114:1420-1432. [PMID: 29590599 DOI: 10.1016/j.bpj.2018.01.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 01/05/2018] [Accepted: 01/30/2018] [Indexed: 01/28/2023] Open
Abstract
The efficiency of intracellular cargo transport from specific sources to target locations is strongly dependent upon molecular motor-assisted motion along the cytoskeleton. Radial transport along microtubules and lateral transport along the filaments of the actin cortex underneath the cell membrane are characteristic for cells with a centrosome. The interplay between the specific cytoskeleton organization and the motor performance results in a spatially inhomogeneous intermittent search strategy. To analyze the efficiency of such intracellular search strategies, we formulate a random velocity model with intermittent arrest states. We evaluate efficiency in terms of mean first passage times for three different, frequently encountered intracellular transport tasks: 1) the narrow escape problem, which emerges during cargo transport to a synapse or other specific region of the cell membrane; 2) the reaction problem, which considers the binding time of two particles within the cell; and 3) the reaction-escape problem, which arises when cargo must be released at a synapse only after pairing with another particle. Our results indicate that cells are able to realize efficient search strategies for various intracellular transport tasks economically through a spatial cytoskeleton organization that involves only a narrow actin cortex rather than a cell body filled with randomly oriented actin filaments.
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Experimental evolution and proximate mechanisms in biology. Synth Syst Biotechnol 2017; 2:253-258. [PMID: 29552649 PMCID: PMC5851904 DOI: 10.1016/j.synbio.2017.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/16/2017] [Accepted: 10/20/2017] [Indexed: 11/23/2022] Open
Abstract
Biological functions – studied by molecular, systems and behavioral biology – are referred to as proximate mechanisms. Why and how they have emerged from the course of evolution are referred to as ultimate mechanisms. Despite the conceptual and technical schism between the disciplines that focus on each, studies from one side can benefit the other. Experimental evolution is an emerging field at the crossroads of functional and evolutionary biology. Herein microorganisms and mammalian cell lines evolve in well-controlled laboratory environments over multiple generations. Phenotypic changes arising from the process are then characterized in genetics and function to understand the evolutionary process. While providing empirical tests to evolutionary questions, such studies also offer opportunities of new insights into proximate mechanisms. Experimental evolution optimizes biological systems by means of adaptation; the adapted systems with their mutations present unique perturbed states of the systems that generate new and often unexpected output/performance. Hence, learning about these states not only adds to but also might deepen knowledge on the proximate processes. To demonstrate this point, five examples in experimental evolution are introduced, and their relevance to functional biology explicated. In some examples, from evolution experiments, updates were made to known proximate processes – gene regulation and cell polarization. In some examples, new contexts were found for known proximate processes – cell division and drug resistance of cancer. In one example, a new cellular mechanism was discovered. These cases identify ways the approach of experimental evolution can be used to ask questions in functional biology.
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28
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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: 8.6] [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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29
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Foteinopoulos P, Mulder BM. A microtubule-based minimal model for spontaneous and persistent spherical cell polarity. PLoS One 2017; 12:e0184706. [PMID: 28931032 PMCID: PMC5607169 DOI: 10.1371/journal.pone.0184706] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 08/22/2017] [Indexed: 11/18/2022] Open
Abstract
We propose a minimal model for the spontaneous and persistent generation of polarity in a spherical cell based on dynamic microtubules and a single mobile molecular component. This component, dubbed the polarity factor, binds to microtubules nucleated from a centrosome located in the center of the cell, is subsequently delivered to the cell membrane, where it diffuses until it unbinds. The only feedback mechanism we impose is that the residence time of the microtubules at the membrane increases with the local density of the polarity factor. We show analytically that this system supports a stable unipolar symmetry-broken state for a wide range of parameters. We validate the predictions of the model by 2D particle-based simulations. Our model provides a route towards the creation of polarity in a minimal cell-like environment using a biochemical reconstitution approach.
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Affiliation(s)
| | - Bela M. Mulder
- Systems Biophysics Department, Institute AMOLF, Amsterdam, the Netherlands
- * E-mail:
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30
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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: 46] [Impact Index Per Article: 5.8] [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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31
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Atay O, Skotheim JM. Spatial and temporal signal processing and decision making by MAPK pathways. J Cell Biol 2017; 216:317-330. [PMID: 28043970 PMCID: PMC5294789 DOI: 10.1083/jcb.201609124] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/25/2016] [Accepted: 12/12/2016] [Indexed: 01/14/2023] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways are conserved from yeast to man and regulate a variety of cellular processes, including proliferation and differentiation. Recent developments show how MAPK pathways perform exquisite spatial and temporal signal processing and underscores the importance of studying the dynamics of signaling pathways to understand their physiological response. The importance of dynamic mechanisms that process input signals into graded downstream responses has been demonstrated in the pheromone-induced and osmotic stress-induced MAPK pathways in yeast and in the mammalian extracellular signal-regulated kinase MAPK pathway. Particularly, recent studies in the yeast pheromone response have shown how positive feedback generates switches, negative feedback enables gradient detection, and coherent feedforward regulation underlies cellular memory. More generally, a new wave of quantitative single-cell studies has begun to elucidate how signaling dynamics determine cell physiology and represents a paradigm shift from descriptive to predictive biology.
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Affiliation(s)
- Oguzhan Atay
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, CA 94305
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32
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Harris SD. Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems. Mycologia 2017; 100:823-32. [DOI: 10.3852/08-177] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Steven D. Harris
- Department of Plant Pathology and Center for Plant Science Innovation, University of Nebraska, Lincoln, Nebraska 68588
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33
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Drawert B, Hellander A, Bales B, Banerjee D, Bellesia G, Daigle BJ, Douglas G, Gu M, Gupta A, Hellander S, Horuk C, Nath D, Takkar A, Wu S, Lötstedt P, Krintz C, Petzold LR. Stochastic Simulation Service: Bridging the Gap between the Computational Expert and the Biologist. PLoS Comput Biol 2016; 12:e1005220. [PMID: 27930676 PMCID: PMC5145134 DOI: 10.1371/journal.pcbi.1005220] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 10/24/2016] [Indexed: 01/25/2023] Open
Abstract
We present StochSS: Stochastic Simulation as a Service, an integrated development environment for modeling and simulation of both deterministic and discrete stochastic biochemical systems in up to three dimensions. An easy to use graphical user interface enables researchers to quickly develop and simulate a biological model on a desktop or laptop, which can then be expanded to incorporate increasing levels of complexity. StochSS features state-of-the-art simulation engines. As the demand for computational power increases, StochSS can seamlessly scale computing resources in the cloud. In addition, StochSS can be deployed as a multi-user software environment where collaborators share computational resources and exchange models via a public model repository. We demonstrate the capabilities and ease of use of StochSS with an example of model development and simulation at increasing levels of complexity.
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Affiliation(s)
- Brian Drawert
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Andreas Hellander
- Department of Information Technology, Division of Scientific Computing, Uppsala University, Uppsala, Sweden
| | - Ben Bales
- Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Debjani Banerjee
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Giovanni Bellesia
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Bernie J. Daigle
- Departments of Biological Sciences and Computer Science, The University of Memphis, Memphis, Tennessee, United States of America
| | - Geoffrey Douglas
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Mengyuan Gu
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Anand Gupta
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Stefan Hellander
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Chris Horuk
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Dibyendu Nath
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Aviral Takkar
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Sheng Wu
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Per Lötstedt
- Department of Information Technology, Division of Scientific Computing, Uppsala University, Uppsala, Sweden
| | - Chandra Krintz
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Linda R. Petzold
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
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34
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Drawert B, Hellander A, Bales B, Banerjee D, Bellesia G, Daigle BJ, Douglas G, Gu M, Gupta A, Hellander S, Horuk C, Nath D, Takkar A, Wu S, Lötstedt P, Krintz C, Petzold LR. Stochastic Simulation Service: Bridging the Gap between the Computational Expert and the Biologist. PLoS Comput Biol 2016. [PMID: 27930676 DOI: 10.1371/journal.pcbi] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
We present StochSS: Stochastic Simulation as a Service, an integrated development environment for modeling and simulation of both deterministic and discrete stochastic biochemical systems in up to three dimensions. An easy to use graphical user interface enables researchers to quickly develop and simulate a biological model on a desktop or laptop, which can then be expanded to incorporate increasing levels of complexity. StochSS features state-of-the-art simulation engines. As the demand for computational power increases, StochSS can seamlessly scale computing resources in the cloud. In addition, StochSS can be deployed as a multi-user software environment where collaborators share computational resources and exchange models via a public model repository. We demonstrate the capabilities and ease of use of StochSS with an example of model development and simulation at increasing levels of complexity.
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Affiliation(s)
- Brian Drawert
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Andreas Hellander
- Department of Information Technology, Division of Scientific Computing, Uppsala University, Uppsala, Sweden
| | - Ben Bales
- Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Debjani Banerjee
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Giovanni Bellesia
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Bernie J Daigle
- Departments of Biological Sciences and Computer Science, The University of Memphis, Memphis, Tennessee, United States of America
| | - Geoffrey Douglas
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Mengyuan Gu
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Anand Gupta
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Stefan Hellander
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Chris Horuk
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Dibyendu Nath
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Aviral Takkar
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Sheng Wu
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Per Lötstedt
- Department of Information Technology, Division of Scientific Computing, Uppsala University, Uppsala, Sweden
| | - Chandra Krintz
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Linda R Petzold
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
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35
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Mutavchiev DR, Leda M, Sawin KE. Remodeling of the Fission Yeast Cdc42 Cell-Polarity Module via the Sty1 p38 Stress-Activated Protein Kinase Pathway. Curr Biol 2016; 26:2921-2928. [PMID: 27746023 PMCID: PMC5106388 DOI: 10.1016/j.cub.2016.08.048] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 07/24/2016] [Accepted: 08/19/2016] [Indexed: 01/27/2023]
Abstract
The Rho family GTPase Cdc42 is a key regulator of eukaryotic cellular organization and cell polarity [1]. In the fission yeast Schizosaccharomyces pombe, active Cdc42 and associated effectors and regulators (the "Cdc42 polarity module") coordinate polarized growth at cell tips by controlling the actin cytoskeleton and exocytosis [2-4]. Localization of the Cdc42 polarity module to cell tips is thus critical for its function. Here we show that the fission yeast stress-activated protein kinase Sty1, a homolog of mammalian p38 MAP kinase, regulates localization of the Cdc42 polarity module. In wild-type cells, treatment with latrunculin A, a drug that leads to actin depolymerization, induces dispersal of the Cdc42 module from cell tips and cessation of polarized growth [5, 6]. We show that latrunculin A treatment also activates the Sty1 MAP kinase pathway and, strikingly, we find that loss of Sty1 MAP kinase signaling prevents latrunculin A-induced dispersal of the Cdc42 module, allowing polarized growth even in complete absence of the actin cytoskeleton. Regulation of the Cdc42 module by Sty1 is independent of Sty1's role in stress-induced gene expression. We also describe a system for activation of Sty1 kinase "on demand" in the absence of any external stress, and use this to show that Sty1 activation alone is sufficient to disperse the Cdc42 module from cell tips in otherwise unperturbed cells. During nitrogen-starvation-induced quiescence, inhibition of Sty1 converts non-growing, depolarized cells into growing, polarized cells. Our results place MAP kinase Sty1 as an important physiological regulator of the Cdc42 polarity module.
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Affiliation(s)
- Delyan R Mutavchiev
- Wellcome Trust 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, C.H. Waddington Building, Max Born Crescent, Edinburgh EH9 3BF, UK
| | - Kenneth E Sawin
- Wellcome Trust 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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36
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Xu B, Bressloff PC. Model of Growth Cone Membrane Polarization via Microtubule Length Regulation. Biophys J 2016; 109:2203-14. [PMID: 26588578 DOI: 10.1016/j.bpj.2015.09.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/04/2015] [Accepted: 09/21/2015] [Indexed: 01/18/2023] Open
Abstract
We present a mathematical model of membrane polarization in growth cones. We proceed by coupling an active transport model of cytosolic proteins along a two-dimensional microtubule (MT) network with a modified Dogterom-Leibler model of MT growth. In particular, we consider a Rac1-stathmin-MT pathway in which the growth and catastrophe rates of MTs are regulated by cytosolic stathmin, while the stathmin is regulated by Rac1 at the membrane. We use regular perturbation theory and numerical simulations to determine the steady-state stathmin concentration, the mean MT length distribution, and the resulting distribution of membrane-bound proteins. We thus show how a nonuniform Rac1 distribution on the membrane generates a polarized distribution of membrane proteins. The mean MT length distribution and hence the degree of membrane polarization are sensitive to the precise form of the Rac1 distribution and parameters such as the catastrophe-promoting constant and tubulin association rate. This is a consequence of the fact that the lateral diffusion of stathmin tends to weaken the effects of Rac1 on the distribution of mean MT lengths.
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Affiliation(s)
- Bin Xu
- Mathematics, University of Utah, Salt Lake City, Utah
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37
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Cortical Polarity of the RING Protein PAR-2 Is Maintained by Exchange Rate Kinetics at the Cortical-Cytoplasmic Boundary. Cell Rep 2016; 16:2156-2168. [DOI: 10.1016/j.celrep.2016.07.047] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 01/10/2016] [Accepted: 07/20/2016] [Indexed: 11/20/2022] Open
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38
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Shao W, Dong J. Polarity in plant asymmetric cell division: Division orientation and cell fate differentiation. Dev Biol 2016; 419:121-131. [PMID: 27475487 DOI: 10.1016/j.ydbio.2016.07.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 07/18/2016] [Accepted: 07/26/2016] [Indexed: 01/04/2023]
Abstract
Asymmetric cell division (ACD) is universally required for the development of multicellular organisms. Unlike animal cells, plant cells have a rigid cellulosic extracellular matrix, the cell wall, which provides physical support and forms communication routes. This fundamental difference leads to some unique mechanisms in plants for generating asymmetries during cell division. However, plants also utilize intrinsically polarized proteins to regulate asymmetric signaling and cell division, a strategy similar to the differentiation mechanism found in animals. Current progress suggests that common regulatory modes, i.e. protein spontaneous clustering and cytoskeleton reorganization, underlie protein polarization in both animal and plant cells. Despite these commonalities, it is important to note that intrinsic mechanisms in plants are heavily influenced by extrinsic cues. To control physical asymmetry in cell division, although our understanding is fragmentary thus far, plants might have evolved novel polarization strategies to orientate cell division plane. Recent studies also suggest that the phytohormone auxin, one of the most pivotal small molecules in plant development, regulates ACD in plants.
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Affiliation(s)
- Wanchen Shao
- Department of Plant Biology and Pathology, Rutgers the State University of New Jersey, NJ 08901, USA
| | - Juan Dong
- Department of Plant Biology and Pathology, Rutgers the State University of New Jersey, NJ 08901, USA; Waksman Institute of Microbiology, Rutgers the State University of New Jersey, NJ 08854, USA.
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39
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Woods B, Lai H, Wu CF, Zyla TR, Savage NS, Lew DJ. Parallel Actin-Independent Recycling Pathways Polarize Cdc42 in Budding Yeast. Curr Biol 2016; 26:2114-26. [PMID: 27476596 DOI: 10.1016/j.cub.2016.06.047] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 05/03/2016] [Accepted: 06/21/2016] [Indexed: 12/31/2022]
Abstract
The highly conserved Rho-family GTPase Cdc42 is an essential regulator of polarity in many different cell types. During polarity establishment, Cdc42 becomes concentrated at a cortical site, where it interacts with downstream effectors to orient the cytoskeleton along the front-back axis. To concentrate Cdc42, loss of Cdc42 by diffusion must be balanced by recycling to the front. In Saccharomyces cerevisiae, the guanine nucleotide dissociation inhibitor (GDI) Rdi1 recycles Cdc42 through the cytoplasm. Loss of Rdi1 slowed but did not eliminate Cdc42 accumulation at the front, suggesting the existence of other recycling pathways. One proposed pathway involves actin-directed trafficking of vesicles carrying Cdc42 to the front. However, we found no role for F-actin in Cdc42 concentration, even in rdi1Δ cells. Instead, Cdc42 was still able to exchange between the membrane and cytoplasm in rdi1Δ cells, albeit at a reduced rate. Membrane-cytoplasm exchange of GDP-Cdc42 was faster than that of GTP-Cdc42, and computational modeling indicated that such exchange would suffice to promote polarization. We also uncovered a novel role for the Cdc42-directed GTPase-activating protein (GAP) Bem2 in Cdc42 polarization. Bem2 was known to act in series with Rdi1 to promote recycling of Cdc42, but we found that rdi1Δ bem2Δ mutants were synthetically lethal, suggesting that they also act in parallel. We suggest that GAP activity cooperates with the GDI to counteract the dissipative effect of a previously unappreciated pathway whereby GTP-Cdc42 escapes from the polarity site through the cytoplasm.
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Affiliation(s)
- Benjamin Woods
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Helen Lai
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Chi-Fang Wu
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Trevin R Zyla
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Natasha S Savage
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
| | - Daniel J Lew
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
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40
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Abstract
Filamentous fungi are extremely polarized organisms, exhibiting continuous growth at their hyphal tips. The hyphal form is related to their pathogenicity in animals and plants, and their high secretion ability for biotechnology. Polarized growth requires a sequential supply of proteins and lipids to the hyphal tip. This transport is managed by vesicle trafficking via the actin and microtubule cytoskeleton. Therefore, the arrangement of the cytoskeleton is a crucial step to establish and maintain the cell polarity. This review summarizes recent findings unraveling the mechanism of polarized growth with special emphasis on the role of actin and microtubule cytoskeleton and polarity marker proteins. Rapid insertions of membranes via highly active exocytosis at hyphal tips could quickly dilute the accumulated polarity marker proteins. Recent findings by a super-resolution microscopy indicate that filamentous fungal cells maintain their polarity at the tips by repeating transient assembly and disassembly of polarity sites.
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Affiliation(s)
- Norio Takeshita
- a Department of Microbiology , Institute for Applied Bioscience, Karlsruhe Institute of Technology (KIT) , Karlsruhe , Germany.,b Faculty of Life and Environmental Sciences , University of Tsukuba , Tsukuba , Japan
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41
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Muller N, Piel M, Calvez V, Voituriez R, Gonçalves-Sá J, Guo CL, Jiang X, Murray A, Meunier N. A Predictive Model for Yeast Cell Polarization in Pheromone Gradients. PLoS Comput Biol 2016; 12:e1004795. [PMID: 27077831 PMCID: PMC4831791 DOI: 10.1371/journal.pcbi.1004795] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/08/2016] [Indexed: 11/18/2022] Open
Abstract
Budding yeast cells exist in two mating types, a and α, which use peptide pheromones to communicate with each other during mating. Mating depends on the ability of cells to polarize up pheromone gradients, but cells also respond to spatially uniform fields of pheromone by polarizing along a single axis. We used quantitative measurements of the response of a cells to α-factor to produce a predictive model of yeast polarization towards a pheromone gradient. We found that cells make a sharp transition between budding cycles and mating induced polarization and that they detect pheromone gradients accurately only over a narrow range of pheromone concentrations corresponding to this transition. We fit all the parameters of the mathematical model by using quantitative data on spontaneous polarization in uniform pheromone concentration. Once these parameters have been computed, and without any further fit, our model quantitatively predicts the yeast cell response to pheromone gradient providing an important step toward understanding how cells communicate with each other.
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Affiliation(s)
- Nicolas Muller
- MAP5, CNRS UMR 8145, Université Paris Descartes, Paris, France
| | - Matthieu Piel
- Institut Curie, CNRS UMR 144, Paris, France
- * E-mail: (MP); (AM); (NM)
| | - Vincent Calvez
- Unité de Mathématiques Pures et Appliquées, CNRS UMR 5669 and équipe-projet INRIA NUMED, École Normale Supérieure de Lyon, Lyon, France
| | - Raphaël Voituriez
- Laboratoire Jean Perrin and Laboratoire de Physique Théorique de la Matière Condensée, UMR 7600 CNRS /UPMC, Paris, France
| | - Joana Gonçalves-Sá
- Molecular and Cell Biology and FAS Center for Systems Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Chin-Lin Guo
- Molecular and Cell Biology and FAS Center for Systems Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Institute of Physics, Academia Sinica, Taiwan
| | - Xingyu Jiang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing, People’s Republic of China
| | - Andrew Murray
- Molecular and Cell Biology and FAS Center for Systems Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail: (MP); (AM); (NM)
| | - Nicolas Meunier
- MAP5, CNRS UMR 8145, Université Paris Descartes, Paris, France
- * E-mail: (MP); (AM); (NM)
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42
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McClure AW, Minakova M, Dyer JM, Zyla TR, Elston TC, Lew DJ. Role of Polarized G Protein Signaling in Tracking Pheromone Gradients. Dev Cell 2016; 35:471-82. [PMID: 26609960 DOI: 10.1016/j.devcel.2015.10.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 09/30/2015] [Accepted: 10/26/2015] [Indexed: 12/16/2022]
Abstract
Yeast cells track gradients of pheromones to locate mating partners. Intuition suggests that uniform distribution of pheromone receptors over the cell surface would yield optimal gradient sensing. However, yeast cells display polarized receptors. The benefit of such polarization was unknown. During gradient tracking, cell growth is directed by a patch of polarity regulators that wanders around the cortex. Patch movement is sensitive to pheromone dose, with wandering reduced on the up-gradient side of the cell, resulting in net growth in that direction. Mathematical modeling suggests that active receptors and associated G proteins lag behind the polarity patch and act as an effective drag on patch movement. In vivo, the polarity patch is trailed by a G protein-rich domain, and this polarized distribution of G proteins is required to constrain patch wandering. Our findings explain why G protein polarization is beneficial and illuminate a novel mechanism for gradient tracking.
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Affiliation(s)
- Allison W McClure
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Maria Minakova
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jayme M Dyer
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Trevin R Zyla
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Timothy C Elston
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Daniel J Lew
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
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43
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de León N, Hoya M, Curto MA, Moro S, Yanguas F, Doncel C, Valdivieso MH. The AP-2 complex is required for proper temporal and spatial dynamics of endocytic patches in fission yeast. Mol Microbiol 2016; 100:409-24. [PMID: 26749213 DOI: 10.1111/mmi.13327] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2016] [Indexed: 12/27/2022]
Abstract
In metazoans the AP-2 complex has a well-defined role in clathrin-mediated endocytosis. By contrast, its direct role in endocytosis in unicellular eukaryotes has been questioned. Here, we report co- immunoprecipitation between the fission yeast AP-2 component Apl3p and clathrin, as well as the genetic interactions between apl3Δ and clc1 and sla2Δ/end4Δ mutants. Furthermore, a double clc1 apl3Δ mutant was found to be defective in FM4-64 uptake. In an otherwise wild-type strain, apl3Δ cells exhibit altered dynamics of the endocytic sites, with a heterogeneous and extended lifetime of early and late markers at the patches. Additionally, around 50% of the endocytic patches exhibit abnormal spatial dynamics, with immobile patches and patches that bounce backwards to the cell surface, showing a pervasive effect of the absence of AP-2. These alterations in the endocytic machinery result in abnormal cell wall synthesis and morphogenesis. Our results complement those found in budding yeast and confirm that a direct role of AP-2 in endocytosis has been conserved throughout evolution.
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Affiliation(s)
- Nagore de León
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Marta Hoya
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - M-Angeles Curto
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Sandra Moro
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Francisco Yanguas
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Cristina Doncel
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - M-Henar Valdivieso
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
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44
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Bruurs LJM, Donker L, Zwakenberg S, Zwartkruis FJ, Begthel H, Knisely AS, Posthuma G, van de Graaf SFJ, Paulusma CC, Bos JL. ATP8B1-mediated spatial organization of Cdc42 signaling maintains singularity during enterocyte polarization. J Cell Biol 2015; 210:1055-63. [PMID: 26416959 PMCID: PMC4586737 DOI: 10.1083/jcb.201505118] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The disease-associated phospholipid flippase ATP8B1 decreases Cdc42 mobility at the apical membrane to ensure the formation of a single apical domain and to maintain healthy lumen architecture. During yeast cell polarization localization of the small GTPase, cell division control protein 42 homologue (Cdc42) is clustered to ensure the formation of a single bud. Here we show that the disease-associated flippase ATPase class I type 8b member 1 (ATP8B1) enables Cdc42 clustering during enterocyte polarization. Loss of this regulation results in increased apical membrane size with scattered apical recycling endosomes and permits the formation of more than one apical domain, resembling the singularity defect observed in yeast. Mechanistically, we show that to become apically clustered, Cdc42 requires the interaction between its polybasic region and negatively charged membrane lipids provided by ATP8B1. Disturbing this interaction, either by ATP8B1 depletion or by introduction of a Cdc42 mutant defective in lipid binding, increases Cdc42 mobility and results in apical membrane enlargement. Re-establishing Cdc42 clustering, by tethering it to the apical membrane or lowering its diffusion, restores normal apical membrane size in ATP8B1-depleted cells. We therefore conclude that singularity regulation by Cdc42 is conserved between yeast and human and that this regulation is required to maintain healthy tissue architecture.
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Affiliation(s)
- Lucas J M Bruurs
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands
| | - Lisa Donker
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands
| | - Susan Zwakenberg
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands
| | - Fried J Zwartkruis
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands
| | - Harry Begthel
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center Utrecht, 3508 AD Utrecht, Netherlands
| | - A S Knisely
- Institute of Liver Studies, King's College Hospital, London SE5 9RS, England, UK
| | - George Posthuma
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands
| | - Stan F J van de Graaf
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Centre, 1105 AZ Amsterdam, Netherlands
| | - Coen C Paulusma
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Centre, 1105 AZ Amsterdam, Netherlands
| | - Johannes L Bos
- Molecular Cancer Research and Cancer Genomics Netherlands, Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, Netherlands
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45
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Hegemann B, Unger M, Lee SS, Stoffel-Studer I, van den Heuvel J, Pelet S, Koeppl H, Peter M. A Cellular System for Spatial Signal Decoding in Chemical Gradients. Dev Cell 2015; 35:458-70. [PMID: 26585298 DOI: 10.1016/j.devcel.2015.10.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/29/2015] [Accepted: 10/18/2015] [Indexed: 12/21/2022]
Abstract
Directional cell growth requires that cells read and interpret shallow chemical gradients, but how the gradient directional information is identified remains elusive. We use single-cell analysis and mathematical modeling to define the cellular gradient decoding network in yeast. Our results demonstrate that the spatial information of the gradient signal is read locally within the polarity site complex using double-positive feedback between the GTPase Cdc42 and trafficking of the receptor Ste2. Spatial decoding critically depends on low Cdc42 activity, which is maintained by the MAPK Fus3 through sequestration of the Cdc42 activator Cdc24. Deregulated Cdc42 or Ste2 trafficking prevents gradient decoding and leads to mis-oriented growth. Our work discovers how a conserved set of components assembles a network integrating signal intensity and directionality to decode the spatial information contained in chemical gradients.
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Affiliation(s)
- Björn Hegemann
- Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland.
| | - Michael Unger
- Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland; Automatic Control Laboratory, ETH Zurich, Physikstrasse 3, 8092 Zürich, Switzerland
| | - Sung Sik Lee
- Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Ingrid Stoffel-Studer
- Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Jasmin van den Heuvel
- Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland
| | - Serge Pelet
- Department of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Heinz Koeppl
- Automatic Control Laboratory, ETH Zurich, Physikstrasse 3, 8092 Zürich, Switzerland; Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Rundeturmstrasse 12, 64283 Darmstadt, Germany
| | - Matthias Peter
- Department of Biology, Institute of Biochemistry, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland.
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46
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Wu CF, Chiou JG, Minakova M, Woods B, Tsygankov D, Zyla TR, Savage NS, Elston TC, Lew DJ. Role of competition between polarity sites in establishing a unique front. eLife 2015; 4:e11611. [PMID: 26523396 PMCID: PMC4728132 DOI: 10.7554/elife.11611] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/01/2015] [Indexed: 01/15/2023] Open
Abstract
Polarity establishment in many cells is thought to occur via positive feedback that reinforces even tiny asymmetries in polarity protein distribution. Cdc42 and related GTPases are activated and accumulate in a patch of the cortex that defines the front of the cell. Positive feedback enables spontaneous polarization triggered by stochastic fluctuations, but as such fluctuations can occur at multiple locations, how do cells ensure that they make only one front? In polarizing cells of the model yeast Saccharomyces cerevisiae, positive feedback can trigger growth of several Cdc42 clusters at the same time, but this multi-cluster stage rapidly evolves to a single-cluster state, which then promotes bud emergence. By manipulating polarity protein dynamics, we show that resolution of multi-cluster intermediates occurs through a greedy competition between clusters to recruit and retain polarity proteins from a shared intracellular pool.
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Affiliation(s)
- Chi-Fang Wu
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, United States
| | - Jian-Geng Chiou
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, United States
| | - Maria Minakova
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Benjamin Woods
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, United States
| | - Denis Tsygankov
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Trevin R Zyla
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, United States
| | - Natasha S Savage
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Timothy C Elston
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Daniel J Lew
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, United States
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47
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Ishitsuka Y, Savage N, Li Y, Bergs A, Grün N, Kohler D, Donnelly R, Nienhaus GU, Fischer R, Takeshita N. Superresolution microscopy reveals a dynamic picture of cell polarity maintenance during directional growth. SCIENCE ADVANCES 2015; 1:e1500947. [PMID: 26665168 PMCID: PMC4673053 DOI: 10.1126/sciadv.1500947] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/14/2015] [Indexed: 05/02/2023]
Abstract
Polar (directional) cell growth, a key cellular mechanism shared among a wide range of species, relies on targeted insertion of new material at specific locations of the plasma membrane. How these cell polarity sites are stably maintained during massive membrane insertion has remained elusive. Conventional live-cell optical microscopy fails to visualize polarity site formation in the crowded cell membrane environment because of its limited resolution. We have used advanced live-cell imaging techniques to directly observe the localization, assembly, and disassembly processes of cell polarity sites with high spatiotemporal resolution in a rapidly growing filamentous fungus, Aspergillus nidulans. We show that the membrane-associated polarity site marker TeaR is transported on microtubules along with secretory vesicles and forms a protein cluster at that point of the apical membrane where the plus end of the microtubule touches. There, a small patch of membrane is added through exocytosis, and the TeaR cluster gets quickly dispersed over the membrane. There is an incessant disassembly and reassembly of polarity sites at the growth zone, and each new polarity site locus is slightly offset from preceding ones. On the basis of our imaging results and computational modeling, we propose a transient polarity model that explains how cell polarity is stably maintained during highly active directional growth.
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Affiliation(s)
- Yuji Ishitsuka
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Natasha Savage
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Yiming Li
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Anna Bergs
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
| | - Nathalie Grün
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
| | - Daria Kohler
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Rebecca Donnelly
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - G. Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute of Nanotechnology, KIT, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Toxicology and Genetics, KIT, 76344 Eggenstein-Leopoldshafen, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
| | - Norio Takeshita
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
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48
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Jost APT, Weiner OD. Probing Yeast Polarity with Acute, Reversible, Optogenetic Inhibition of Protein Function. ACS Synth Biol 2015; 4:1077-85. [PMID: 26035630 DOI: 10.1021/acssynbio.5b00053] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We recently developed a technique for rapidly and reversibly inhibiting protein function through light-inducible sequestration of proteins away from their normal sites of action. Here, we adapt this method for inducible inactivation of Bem1, a scaffold protein involved in budding yeast polarity. We find that acute inhibition of Bem1 produces profound defects in cell polarization and cell viability that are not observed in bem1Δ. By disrupting Bem1 activity at specific points in the cell cycle, we demonstrate that Bem1 is essential for the establishment of polarity and bud emergence but is dispensable for the growth of an emerged bud. By taking advantage of the reversibility of Bem1 inactivation, we show that pole size scales with cell size, and that this scaling is dependent on the actin cytoskeleton. Our experiments reveal how rapid reversible inactivation of protein function complements traditional genetic approaches. This strategy should be widely applicable to other biological contexts.
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Affiliation(s)
- Anna Payne-Tobin Jost
- Cardiovascular Research Institute
and Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California 94158, United States
| | - Orion D. Weiner
- Cardiovascular Research Institute
and Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California 94158, United States
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49
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Laan L, Koschwanez JH, Murray AW. Evolutionary adaptation after crippling cell polarization follows reproducible trajectories. eLife 2015; 4. [PMID: 26426479 PMCID: PMC4630673 DOI: 10.7554/elife.09638] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/30/2015] [Indexed: 12/21/2022] Open
Abstract
Cells are organized by functional modules, which typically contain components whose removal severely compromises the module's function. Despite their importance, these components are not absolutely conserved between parts of the tree of life, suggesting that cells can evolve to perform the same biological functions with different proteins. We evolved Saccharomyces cerevisiae for 1000 generations without the important polarity gene BEM1. Initially the bem1∆ lineages rapidly increase in fitness and then slowly reach >90% of the fitness of their BEM1 ancestors at the end of the evolution. Sequencing their genomes and monitoring polarization reveals a common evolutionary trajectory, with a fixed sequence of adaptive mutations, each improving cell polarization by inactivating proteins. Our results show that organisms can be evolutionarily robust to physiologically destructive perturbations and suggest that recovery by gene inactivation can lead to rapid divergence in the parts list for cell biologically important functions. DOI:http://dx.doi.org/10.7554/eLife.09638.001 Cells use the genetic instructions provided by genes in particular combinations called ‘modules’ to perform particular jobs. Very different organisms can share many of the same modules because certain abilities are fundamental to the survival of all cells and so they have been retained over the course of evolution. That said, these modules may not necessarily involve the same genes because it is often possible to achieve the same result using different components. One way to study how those modules can diversify is to deliberately disrupt one of the genes in a module, and observe how the organism and its descendants respond over many generations. Other genes in these organisms may acquire genetic mutations that enable the genes to take on the role of the missing protein. However, the removal of a single component can be detrimental to the survival of the organisms or may affect many different processes. This can make it difficult to understand what is going on. A gene called BEM1 is crucial for yeast cells to establish polarity, that is, to allow the different sides of a cell to become distinct from one another. This activity is essential for the yeast to replicate itself. Previous studies have shown that the BEM1 gene had a different role in other species of fungi, which suggests that yeast may have other genes that previously assumed the role that BEM1 does now. In this study, Laan et al. removed BEM1 from yeast and allowed the population of mutant cells to evolve for a thousand generations. The approach differs from previous studies because Laan et al. deliberately selected for yeast that had acquired multiple genetic mutations that can together almost fully compensate for the loss of BEM1. Initially, the mutant cells grew very slowly, were abnormal in shape and likely to burst open. However, by the end of the experiment, the cells were able to grow almost as well as the original yeast cells had before the gene deletion. Genetic analysis revealed that the deletion of BEM1 triggers the inactivation of other genes that are also involved in the regulation of polarity, which largely restored the ability of the disrupted polarity module to work. This restoration follows a ‘reproducible trajectory’, as the same genes were switched off in the same order in different populations of yeast that were studied at the same time. The work is an example of reproducible evolution, whereby a specific order of changes to gene activity repeatedly enables cells with severe defects in important processes to adapt and restore a gene module, using whatever components they have left. The next challenge will be to understand how the particular roles of important modules affect their adaptability. DOI:http://dx.doi.org/10.7554/eLife.09638.002
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Affiliation(s)
- Liedewij Laan
- FAS Center for Systems Biology, Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - John H Koschwanez
- FAS Center for Systems Biology, Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Andrew W Murray
- FAS Center for Systems Biology, Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
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50
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Martin SG. Spontaneous cell polarization: Feedback control of Cdc42 GTPase breaks cellular symmetry. Bioessays 2015; 37:1193-201. [PMID: 26338468 DOI: 10.1002/bies.201500077] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Spontaneous polarization without spatial cues, or symmetry breaking, is a fundamental problem of spatial organization in biological systems. This question has been extensively studied using yeast models, which revealed the central role of the small GTPase switch Cdc42. Active Cdc42-GTP forms a coherent patch at the cell cortex, thought to result from amplification of a small initial stochastic inhomogeneity through positive feedback mechanisms, which induces cell polarization. Here, I review and discuss the mechanisms of Cdc42 activity self-amplification and dynamic turnover. A robust Cdc42 patch is formed through the combined effects of Cdc42 activity promoting its own activation and active Cdc42-GTP displaying reduced membrane detachment and lateral diffusion compared to inactive Cdc42-GDP. I argue the role of the actin cytoskeleton in symmetry breaking is not primarily to transport Cdc42 to the active site. Finally, negative feedback and competition mechanisms serve to control the number of polarization sites.
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Affiliation(s)
- Sophie G Martin
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
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