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Singh D, Liu Y, Zhu YH, Zhang S, Naegele S, Wu JQ. Septins function in exocytosis via physical interactions with the exocyst complex in fission yeast cytokinesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.09.602728. [PMID: 39026698 PMCID: PMC11257574 DOI: 10.1101/2024.07.09.602728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Septins can function as scaffolds for protein recruitment, membrane-bound diffusion barriers, or membrane curvature sensors. Septins are important for cytokinesis, but their exact roles are still obscure. In fission yeast, four septins (Spn1 to Spn4) accumulate at the rim of the division plane as rings. The octameric exocyst complex, which tethers exocytic vesicles to the plasma membrane, exhibits a similar localization and is essential for plasma membrane deposition during cytokinesis. Without septins, the exocyst spreads across the division plane but absent from the rim during septum formation. These results suggest that septins and the exocyst physically interact for proper localization. Indeed, we predicted six pairs of direct interactions between septin and exocyst subunits by AlphaFold2 ColabFold, most of them are confirmed by co-immunoprecipitation and yeast two-hybrid assays. Exocyst mislocalization results in mistargeting of secretory vesicles and their cargos, which leads to cell-separation delay in septin mutants. Our results indicate that septins guide the targeting of exocyst complex on the plasma membrane for vesicle tethering during cytokinesis through direct physical interactions.
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Affiliation(s)
- Davinder Singh
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States
| | - Yajun Liu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States
| | - Yi-Hua Zhu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States
| | - Sha Zhang
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States
| | - Shelby Naegele
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, United States
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2
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Cui FJ, Fu X, Sun L, Zan XY, Meng LJ, Sun WJ. Recent insights into glucans biosynthesis and engineering strategies in edible fungi. Crit Rev Biotechnol 2023:1-18. [PMID: 38105513 DOI: 10.1080/07388551.2023.2289341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 04/21/2023] [Indexed: 12/19/2023]
Abstract
Fungal α/β-glucans have significant importance in cellular functions including cell wall structure, host-pathogen interactions and energy storage, and wide application in high-profile fields, including food, nutrition, and pharmaceuticals. Fungal species and their growth/developmental stages result in a diversity of glucan contents, structures and bioactivities. Substantial progresses have been made to elucidate the fine structures and functions, and reveal the potential molecular synthesis pathway of fungal α/β-glucans. Herein, we review the current knowledge about the biosynthetic machineries, including: precursor UDP-glucose synthesis, initiation, elongation/termination and remodeling of α/β-glucan chains, and molecular regulation to maximally produce glucans in edible fungi. This review would provide future perspectives to biosynthesize the targeted glucans and reveal the catalytic mechanism of enzymes associated with glucan synthesis, including: UDP-glucose pyrophosphate phosphorylases (UGP), glucan synthases, and glucanosyltransferases in edible fungi.
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Affiliation(s)
- Feng-Jie Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-production, Dexing, P. R. China
| | - Xin Fu
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Lei Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Xin-Yi Zan
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Li-Juan Meng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
| | - Wen-Jing Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, P. R. China
- Jiangxi Provincial Engineering and Technology Center for Food Additives Bio-production, Dexing, P. R. China
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3
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Willet AH, Wos M, Igarashi MG, Ren L, Turner LA, Gould KL. Elevated levels of sphingolipid MIPC in the plasma membrane disrupt the coordination of cell growth with cell wall formation in fission yeast. PLoS Genet 2023; 19:e1010987. [PMID: 37792890 PMCID: PMC10578601 DOI: 10.1371/journal.pgen.1010987] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/16/2023] [Accepted: 09/19/2023] [Indexed: 10/06/2023] Open
Abstract
Coupling cell wall expansion with cell growth is a universal challenge faced by walled organisms. Mutations in Schizosaccharomyces pombe css1, which encodes a PM inositol phosphosphingolipid phospholipase C, prevent cell wall expansion but not synthesis of cell wall material. To probe how Css1 modulates cell wall formation we used classical and chemical genetics coupled with quantitative mass spectrometry. We found that elevated levels of the sphingolipid biosynthetic pathway's final product, mannosylinositol phosphorylceramide (MIPC), specifically correlated with the css1-3 phenotype. We also found that an apparent indicator of sphingolipids and a sterol biosensor accumulated at the cytosolic face of the PM at cell tips and the division site of css1-3 cells and, in accord, the PM in css1-3 was less dynamic than in wildtype cells. Interestingly, disrupting the protein glycosylation machinery recapitulated the css1-3 phenotype and led us to investigate Ghs2, a glycosylated PM protein predicted to modify cell wall material. Disrupting Ghs2 function led to aberrant cell wall material accumulation suggesting Ghs2 is dysfunctional in css1-3. We conclude that preventing an excess of MIPC in the S. pombe PM is critical to the function of key PM-localized proteins necessary for coupling growth with cell wall formation.
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Affiliation(s)
- Alaina H. Willet
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, United States of America
| | - Marcin Wos
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, United States of America
| | - Maya G. Igarashi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, United States of America
| | - Liping Ren
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, United States of America
| | - Lesley A. Turner
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, United States of America
| | - Kathleen L. Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, United States of America
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4
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Rossi AM, Bohnert KA, Gould KL. The fission yeast cytokinetic ring component Fic1 promotes septum formation. Biol Open 2023; 12:308901. [PMID: 37158439 PMCID: PMC10184318 DOI: 10.1242/bio.059957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 04/19/2023] [Indexed: 05/10/2023] Open
Abstract
In Schizosaccharomyces pombe, septum formation is coordinated with cytokinetic ring constriction but the mechanisms linking these events are unclear. In this study, we explored the role of the cytokinetic ring component Fic1, first identified by its interaction with the F-BAR protein Cdc15, in septum formation. We found that the fic1 phospho-ablating mutant, fic1-2A, is a gain-of-function allele that suppresses myo2-E1, the temperature-sensitive allele of the essential type-II myosin, myo2. This suppression is achieved by the promotion of septum formation and required Fic1's interaction with the F-BAR proteins Cdc15 and Imp2. Additionally, we found that Fic1 interacts with Cyk3 and that this interaction was likewise required for Fic1's role in septum formation. Fic1, Cdc15, Imp2, and Cyk3 are the orthologs of the Saccharomyces cerevisiae ingression progression complex, which stimulates the chitin synthase Chs2 to promote primary septum formation. However, our findings indicate that Fic1 promotes septum formation and cell abscission independently of the S. pombe Chs2 ortholog. Thus, while similar complexes exist in the two yeasts that each promote septation, they appear to have different downstream effectors.
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Affiliation(s)
- Anthony M Rossi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - K Adam Bohnert
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
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Onwubiko UN, Kalathil D, Koory E, Pokharel S, Roberts H, Mitoubsi A, Das M. Cdc42 prevents precocious Rho1 activation during cytokinesis in a Pak1-dependent manner. J Cell Sci 2023; 136:jcs261160. [PMID: 37039135 PMCID: PMC10163358 DOI: 10.1242/jcs.261160] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 03/15/2023] [Indexed: 04/12/2023] Open
Abstract
During cytokinesis, a series of coordinated events partition a dividing cell. Accurate regulation of cytokinesis is essential for proliferation and genome integrity. In fission yeast, these coordinated events ensure that the actomyosin ring and septum start ingressing only after chromosome segregation. How cytokinetic events are coordinated remains unclear. The GTPase Cdc42 promotes recruitment of certain cell wall-building enzymes whereas the GTPase Rho1 activates these enzymes. We show that Cdc42 prevents early Rho1 activation during fission yeast cytokinesis. Using an active Rho probe, we find that although the Rho1 activators Rgf1 and Rgf3 localize to the division site in early anaphase, Rho1 is not activated until late anaphase, just before the onset of ring constriction. We find that loss of Cdc42 activation enables precocious Rho1 activation in early anaphase. Furthermore, we provide functional and genetic evidence that Cdc42-dependent Rho1 inhibition is mediated by the Cdc42 target Pak1 kinase. Our work proposes a mechanism of Rho1 regulation by active Cdc42 to coordinate timely septum formation and cytokinesis fidelity.
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Affiliation(s)
- Udo N. Onwubiko
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Dhanya Kalathil
- Biology Department, Boston College, Chestnut Hill, MA 02467, USA
| | - Emma Koory
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Sahara Pokharel
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Hayden Roberts
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Ahmad Mitoubsi
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Maitreyi Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
- Biology Department, Boston College, Chestnut Hill, MA 02467, USA
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6
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Rossi AM, Bohnert KA, Gould KL. The fission yeast cytokinetic ring component Fic1 promotes septum formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.13.532462. [PMID: 36993237 PMCID: PMC10054984 DOI: 10.1101/2023.03.13.532462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
In Schizosaccharomyces pombe septum formation is coordinated with cytokinetic ring constriction but the mechanisms linking these events are unclear. In this study, we explored the role of the cytokinetic ring component Fic1, first identified by its interaction with the F-BAR protein Cdc15, in septum formation. We found that the fic1 phospho-ablating mutant, fic1-2A , is a gain-of-function allele that suppresses myo2-E1 , the temperature-sensitive allele of the essential type-II myosin, myo2 . This suppression is achieved by the promotion of septum formation and required Fic1's interaction with the F-BAR proteins Cdc15 and Imp2. Additionally, we found that Fic1 interacts with Cyk3 and that this interaction was likewise required for Fic1's role in septum formation. Fic1, Cdc15, Imp2, and Cyk3 are the orthologs of the Saccharomyces cerevisiae ingression progression complex, which stimulates the chitin synthase Chs2 to promote primary septum formation. However, our findings indicate that Fic1 promotes septum formation and cell abscission independently of the S. pombe Chs2 ortholog. Thus, while similar complexes exist in the two yeasts that each promote septation, they appear to have different downstream effectors. Summary Statement The S. pombe cytokinetic ring protein Fic1 promotes septum formation in a manner dependent on interactions with the cytokinetic ring components Cdc15, Imp2, and Cyk3.
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7
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San-Quirico E, Curto MÁ, Gómez-Delgado L, Moreno MB, Pérez P, Ribas JC, Cortés JCG. Analysis of the Localization of Schizosaccharomyces pombe Glucan Synthases in the Presence of the Antifungal Agent Caspofungin. Int J Mol Sci 2023; 24:ijms24054299. [PMID: 36901728 PMCID: PMC10002279 DOI: 10.3390/ijms24054299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
In recent years, invasive fungal infections have emerged as a common source of infections in immunosuppressed patients. All fungal cells are surrounded by a cell wall that is essential for cell integrity and survival. It prevents cell death and lysis resulting from high internal turgor pressure. Since the cell wall is not present in animal cells, it is an ideal target for selective invasive fungal infection treatments. The antifungal family known as echinocandins, which specifically inhibit the synthesis of the cell wall β(13)glucan, has been established as an alternative treatment for mycoses. To explore the mechanism of action of these antifungals, we analyzed the cell morphology and glucan synthases localization in Schizosaccharomyces pombe cells during the initial times of growth in the presence of the echinocandin drug caspofungin. S. pombe are rod-shaped cells that grow at the poles and divide by a central division septum. The cell wall and septum are formed by different glucans, which are synthesized by four essential glucan synthases: Bgs1, Bgs3, Bgs4, and Ags1. Thus, S. pombe is not only a perfect model for studying the synthesis of the fungal β(1-3)glucan, but also it is ideal for examining the mechanisms of action and resistance of cell wall antifungals. Herein, we examined the cells in a drug susceptibility test in the presence of either lethal or sublethal concentrations of caspofungin, finding that exposure to the drug for long periods at high concentrations (>10 µg/mL) induced cell growth arrest and the formation of rounded, swollen, and dead cells, whereas low concentrations (<10 µg/mL) permitted cell growth with a mild effect on cell morphology. Interestingly, short-term treatments with either high or low concentrations of the drug induced effects contrary to those observed in the susceptibility tests. Thus, low drug concentrations induced a cell death phenotype that was not observed at high drug concentrations, which caused transient fungistatic cell growth arrest. After 3 h, high concentrations of the drug caused the following: (i) a decrease in the GFP-Bgs1 fluorescence level; (ii) altered locations of Bgs3, Bgs4, and Ags1; and (iii) a simultaneous accumulation of cells with calcofluor-stained incomplete septa, which at longer times resulted in septation uncoupling from plasma membrane ingression. The incomplete septa revealed with calcofluor were found to be complete when observed via the membrane-associated GFP-Bgs or Ags1-GFP. Finally, we found that the accumulation of incomplete septa depended on Pmk1, the last kinase of the cell wall integrity pathway.
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8
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Bellingham-Johnstun K, Commer B, Levesque B, Tyree ZL, Laplante C. Imp2p forms actin-dependent clusters and imparts stiffness to the contractile ring. Mol Biol Cell 2022; 33:ar145. [PMID: 36287824 PMCID: PMC9727792 DOI: 10.1091/mbc.e22-06-0221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The contractile ring must anchor to the plasma membrane and cell wall to transmit its tension. F-BAR domain containing proteins including Imp2p and Cdc15p in fission yeast are likely candidate anchoring proteins based on their mutant phenotypes. Cdc15p is a node component, links the actin bundle to the plasma membrane, recruits Bgs1p to the division plane, prevents contractile ring sliding, and contributes to the stiffness of the contractile ring. Less is known about Imp2p. We found that similarly to Cdc15p, Imp2p contributes to the stiffness of the contractile ring and assembles into protein clusters. Imp2p clusters contain approximately eight Imp2p dimers and depend on the actin network for their stability at the division plane. Importantly, Imp2p and Cdc15p reciprocally affect the amount of each other in the contractile ring, indicating that the two proteins influence each other during cytokinesis, which may partially explain their similar phenotypes.
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Affiliation(s)
| | - Blake Commer
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
| | - Brié Levesque
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
| | - Zoe L Tyree
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
| | - Caroline Laplante
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607
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9
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Fission Yeast Rho1p-GEFs: From Polarity and Cell Wall Synthesis to Genome Stability. Int J Mol Sci 2022; 23:ijms232213888. [PMID: 36430366 PMCID: PMC9697909 DOI: 10.3390/ijms232213888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Rho1p is a membrane-associated protein that belongs to the Rho family of small GTPases. These proteins coordinate processes such as actin remodelling and polarised secretion to maintain the shape and homeostasis of yeast cells. In response to extracellular stimuli, Rho1p undergoes conformational switching between a guanosine triphosphate (GTP)-bound active state and a guanosine diphosphate (GDP)-bound inactive state. Cycling is improved with guanine nucleotide exchange factor (GEF) activity necessary to activate signalling and GTPase activating protein (GAP) activity required for subsequent signal depletion. This review focuses on fission yeast Rho1p GEFs, Rgf1p, Rgf2p, and Rgf3p that belong to the family of DH-PH domain-containing Dbl-related GEFs. They are multi-domain proteins that detect biological signals that induce or inhibit their catalytic activity over Rho1p. Each of them activates Rho1p in different places and times. Rgf1p acts preferentially during polarised growth. Rgf2p is required for sporulation, and Rgf3p plays an essential function in septum synthesis. In addition, we outline the noncanonical roles of Rho1p-GEFs in genomic instability.
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10
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Sinha D, Ivan D, Gibbs E, Chetluru M, Goss J, Chen Q. Fission yeast polycystin Pkd2p promotes cell size expansion and antagonizes the Hippo-related SIN pathway. J Cell Sci 2022; 135:274457. [PMID: 35099006 PMCID: PMC8919332 DOI: 10.1242/jcs.259046] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 01/14/2022] [Indexed: 11/20/2022] Open
Abstract
Polycystins are conserved mechanosensitive channels whose mutations lead to the common human renal disorder autosomal dominant polycystic kidney disease (ADPKD). Previously, we discovered that the plasma membrane-localized fission yeast polycystin homolog Pkd2p is an essential protein required for cytokinesis; however, its role remains unclear. Here, we isolated a novel temperature-sensitive pkd2 mutant, pkd2-B42. Among the strong growth defects of this mutant, the most striking was that many mutant cells often lost a significant portion of their volume in just 5 min followed by a gradual recovery, a process that we termed 'deflation'. Unlike cell lysis, deflation did not result in plasma membrane rupture and occurred independently of cell cycle progression. The tip extension of pkd2-B42 cells was 80% slower than that of wild-type cells, and their turgor pressure was 50% lower. Both pkd2-B42 and the hypomorphic depletion mutant pkd2-81KD partially rescued mutants of the septation initiation network (SIN), a yeast Hippo-related signaling pathway, by preventing cell lysis, enhancing septum formation and doubling the number of Sid2p and Mob1p molecules at the spindle pole bodies. We conclude that Pkd2p promotes cell size expansion during interphase by regulating turgor pressure and antagonizes the SIN during cytokinesis. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Debatrayee Sinha
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA
| | - Denisa Ivan
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA
| | - Ellie Gibbs
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA 02482, USA
| | - Madhurya Chetluru
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA
| | - John Goss
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA 02482, USA
| | - Qian Chen
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA,Author for correspondence ()
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11
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Longo LVG, Goodyear EG, Zhang S, Kudryashova E, Wu JQ. Involvement of Smi1 in cell wall integrity and glucan synthase Bgs4 localization during fission yeast cytokinesis. Mol Biol Cell 2021; 33:ar17. [PMID: 34910579 PMCID: PMC9236143 DOI: 10.1091/mbc.e21-04-0214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Cytokinesis is the final step of the cell-division cycle. In fungi, it relies on the coordination of constriction of an actomyosin contractile ring and construction of the septum at the division site. Glucan synthases synthesize glucans, which are the major components in fungal cell walls and division septa. It is known that Rho1 and Rho2 GTPases regulate glucan synthases Bgs1, Bgs4, and Ags1, and that Sbg1 and the F-BAR protein Cdc15 play roles in Bgs1 stability and delivery to the plasma membrane. Here we characterize Smi1, an intrinsically disordered protein that interacts with Bgs4 and regulates its trafficking and localization in fission yeast. Smi1 is important for septum integrity, and its absence causes severe lysis during cytokinesis. Smi1 localizes to secretory vesicles and moves together with Bgs4 toward the division site. The concentrations of the glucan synthases Bgs1 and Bgs4 and the glucanases Agn1 and Bgl2 decrease at the division site in the smi1 mutant, but Smi1 seems to be more specific to Bgs4. Mistargeting of Smi1 to mitochondria mislocalizes Bgs4 but not Bgs1. Together, our data reveal a novel regulator of glucan synthases and glucanases, Smi1, which is more important for Bgs4 trafficking, stability, and localization during cytokinesis.
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Affiliation(s)
- Larissa V G Longo
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210
| | - Evelyn G Goodyear
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210
| | - Sha Zhang
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210
| | - Elena Kudryashova
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio 43210.,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio 43210
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12
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Nishimura S. Marine natural products targeting the eukaryotic cell membrane. J Antibiot (Tokyo) 2021; 74:769-785. [PMID: 34493848 DOI: 10.1038/s41429-021-00468-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/16/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023]
Abstract
The cell membrane, with high fluidity and alternative curvatures, maintains the robust integrity to distinguish inner and outer space of cells or organelles. Lipids are the main components of the cell membrane, but their functions are largely unknown. Even the visualization of lipids is not straightforward since modification of lipids often hampers its correct physical properties. Many natural products target cell membranes, some of which are used as pharmaceuticals and/or research tools. They show specific recognition on lipids, and thus exhibit desired pharmacological effects and unique biological phenotypes. This review is a catalog of marine natural products that target eukaryotic cell membranes. Chemical structures, biological activities, and molecular mechanisms are summarized. I hope that this review will be helpful for readers to notice the potential of marine natural products in the exploration of the function of lipids and the druggability of eukaryotic cell membranes.
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Affiliation(s)
- Shinichi Nishimura
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan.
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13
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Thiyagarajan S, Mcdargh Z, Wang S, O’shaughnessy B. Contractile ring constriction and septation in fission yeast are integrated mutually stabilizing processes.. [DOI: 10.1101/2021.06.25.449700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
AbstractIn common with other cellular machineries, the actomyosin contractile ring that divides cells during cytokinesis does not operate in isolation. Contractile rings in animal cells interact with contiguous actomyosin cortex, while ring constriction in many cell-walled organisms couples tightly to cell wall growth. In fission yeast, a septum grows in the wake of the constricting ring, ensuring cytokinesis leaves two daughter cells fully enclosed by cell wall. Here we mathematical modeled the integrated constriction-septation system in fission yeast, with a kinetic growth model evolving the 3D septum shape coupled to a molecularly explicit simulation of the contractile ring highly constrained by experimental data. Simulations revealed influences in both directions, stabilizing the ring-septum system as a whole. By providing a smooth circular anchoring surface for the ring, the inner septum leading edge stabilized ring organization and tension production; by mechanically regulating septum circularity and in-plane growth, ring tension stabilized septum growth and shape. Genetic or pharmacological perturbation of either subsystem destabilized this delicate balance, precipitating uncontrolled positive feedback with disastrous morphological and functional consequences. Thus, high curvature septum irregularities triggered bridging instabilities, in which contractile ring segments became unanchored. Bridging abolished the local tension-mediated septum shape regulation, exacerbating the irregularity in a mutually destabilizing runaway process. Our model explains a number of previously mysterious experimental observations, including unanchoring of ring segments observed in cells with mutations in the septum-growing β-glucan synthases, and irregular septa in cells with mutations in the contractile ring myosin-II Myo2. Thus, the contractile ring and cell wall growth cellular machineries operate as a single integrated system, whose stability relies on mutual regulation by the two subsystems.
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14
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Plaza V, Silva-Moreno E, Castillo L. Breakpoint: Cell Wall and Glycoproteins and their Crucial Role in the Phytopathogenic Fungi Infection. Curr Protein Pept Sci 2021; 21:227-244. [PMID: 31490745 DOI: 10.2174/1389203720666190906165111] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/02/2019] [Accepted: 08/17/2019] [Indexed: 01/09/2023]
Abstract
The cell wall that surrounds fungal cells is essential for their survival, provides protection against physical and chemical stresses, and plays relevant roles during infection. In general, the fungal cell wall is composed of an outer layer of glycoprotein and an inner skeletal layer of β-glucans or α- glucans and chitin. Chitin synthase genes have been shown to be important for septum formation, cell division and virulence. In the same way, chitin can act as a potent elicitor to activate defense response in several plant species; however, the fungi can convert chitin to chitosan during plant infection to evade plant defense mechanisms. Moreover, α-1,3-Glucan, a non-degradable polysaccharide in plants, represents a key feature in fungal cell walls formed in plants and plays a protective role for this fungus against plant lytic enzymes. A similar case is with β-1,3- and β-1,6-glucan which are essential for infection, structure rigidity and pathogenicity during fungal infection. Cell wall glycoproteins are also vital to fungi. They have been associated with conidial separation, the increase of chitin in conidial cell walls, germination, appressorium formation, as well as osmotic and cell wall stress and virulence; however, the specific roles of glycoproteins in filamentous fungi remain unknown. Fungi that can respond to environmental stimuli distinguish these signals and relay them through intracellular signaling pathways to change the cell wall composition. They play a crucial role in appressorium formation and penetration, and release cell wall degrading enzymes, which determine the outcome of the interaction with the host. In this review, we highlight the interaction of phypatophogen cell wall and signaling pathways with its host and their contribution to fungal pathogenesis.
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Affiliation(s)
- Verónica Plaza
- Laboratorio de Biología Molecular y Bioquímica, Departamento de Biología, Universidad de La Serena, La Serena, Chile
| | - Evelyn Silva-Moreno
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Temuco, Chile
| | - Luis Castillo
- Laboratorio de Biología Molecular y Bioquímica, Departamento de Biología, Universidad de La Serena, La Serena, Chile
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15
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Evolutionary Overview of Molecular Interactions and Enzymatic Activities in the Yeast Cell Walls. Int J Mol Sci 2020; 21:ijms21238996. [PMID: 33256216 PMCID: PMC7730094 DOI: 10.3390/ijms21238996] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 11/25/2022] Open
Abstract
Fungal cell walls are composed of a polysaccharide network that serves as a scaffold in which different glycoproteins are embedded. Investigation of fungal cell walls, besides simple identification and characterization of the main cell wall building blocks, covers the pathways and regulations of synthesis of each individual component of the wall and biochemical reactions by which they are cross-linked and remodeled in response to different growth phase and environmental signals. In this review, a survey of composition and organization of so far identified and characterized cell wall components of different yeast genera including Saccharomyces, Candida, Kluyveromyces, Yarrowia, and Schizosaccharomyces are presented with the focus on their cell wall proteomes.
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16
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Poddar A, Sidibe O, Ray A, Chen Q. Calcium spikes accompany cleavage furrow ingression and cell separation during fission yeast cytokinesis. Mol Biol Cell 2020; 32:15-27. [PMID: 33175606 PMCID: PMC8098820 DOI: 10.1091/mbc.e20-09-0609] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The role of calcium signaling in cytokinesis has long remained ambiguous. Past studies of embryonic cell division discovered that calcium concentration increases transiently at the division plane just before cleavage furrow ingression, suggesting that these calcium transients could trigger contractile ring constriction. However, such calcium transients have only been found in animal embryos and their function remains controversial. We explored cytokinetic calcium transients in the fission yeast Schizosaccharomyces pombe by adopting GCaMP, a genetically encoded calcium indicator, to determine the intracellular calcium level of this model organism. We validated GCaMP as a highly sensitive calcium reporter in fission yeast, allowing us to capture calcium transients triggered by osmotic shocks. We identified a correlation between the intracellular calcium level and cell division, consistent with the existence of calcium transients during cytokinesis. Using time-lapse microscopy and quantitative image analysis, we discovered calcium spikes both at the start of cleavage furrow ingression and the end of cell separation. Inhibition of these calcium spikes slowed the furrow ingression and led to frequent lysis of daughter cells. We conclude that like the larger animal embryos, fission yeast triggers calcium transients that may play an important role in cytokinesis (197).
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Affiliation(s)
- Abhishek Poddar
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Oumou Sidibe
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Aniruddha Ray
- Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606
| | - Qian Chen
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
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17
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Onwubiko UN, Rich-Robinson J, Mustaf RA, Das ME. Cdc42 promotes Bgs1 recruitment for septum synthesis and glucanase localization for cell separation during cytokinesis in fission yeast. Small GTPases 2020; 12:257-264. [PMID: 32182184 DOI: 10.1080/21541248.2020.1743926] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cytokinesis in fission yeast involves actomyosin ring constriction concurrent to septum synthesis followed by septum digestion resulting in cell separation. A recent report indicates that endocytosis is required for septum synthesis and cell separation. The conserved GTPase Cdc42 is required for membrane trafficking and promotes endocytosis. Cdc42 is activated by Guanine nucleotide exchange factors (GEFs). Cdc42 GEFs have been shown to promote timely initiation of septum synthesis and proper septum morphology. Here we show that Cdc42 promotes the recruitment of the major primary septum synthesizing enzyme Bgs1 and consequent ring constriction. Cdc42 is also required for proper localization of the septum digesting glucanases at the division site. Thus, Cdc42 is required to promote multiple steps during cytokinesis.
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Affiliation(s)
- Udo N Onwubiko
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| | - Julie Rich-Robinson
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| | - Rose Albu Mustaf
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| | - Maitreyi E Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
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18
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Nishimura S, Matsumori N. Chemical diversity and mode of action of natural products targeting lipids in the eukaryotic cell membrane. Nat Prod Rep 2020; 37:677-702. [PMID: 32022056 DOI: 10.1039/c9np00059c] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Covering: up to 2019Nature furnishes bioactive compounds (natural products) with complex chemical structures, yet with simple, sophisticated molecular mechanisms. When natural products exhibit their activities in cells or bodies, they first have to bind or react with a target molecule in/on the cell. The cell membrane is a major target for bioactive compounds. Recently, our understanding of the molecular mechanism of interactions between natural products and membrane lipids progressed with the aid of newly-developed analytical methods. New technology reconnects old compounds with membrane lipids, while new membrane-targeting molecules are being discovered through the screening for antimicrobial potential of natural products. This review article focuses on natural products that bind to eukaryotic membrane lipids, and includes clinically important molecules and key research tools. The chemical diversity of membrane-targeting natural products and the molecular basis of lipid recognition are described. The history of how their mechanism was unveiled, and how these natural products are used in research are also mentioned.
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Affiliation(s)
- Shinichi Nishimura
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan.
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19
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Wagener J, Striegler K, Wagener N. α- and β-1,3-Glucan Synthesis and Remodeling. Curr Top Microbiol Immunol 2020; 425:53-82. [PMID: 32193600 DOI: 10.1007/82_2020_200] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Glucans are characteristic and major constituents of fungal cell walls. Depending on the species, different glucan polysaccharides can be found. These differ in the linkage of the D-glucose monomers which can be either in α- or β-conformation and form 1,3, 1,4 or 1,6 O-glycosidic bonds. The linkages and polymer lengths define the physical properties of the glucan macromolecules, which may form a scaffold for other cell wall structures and influence the rigidity and elasticity of the wall. β-1,3-glucan is essential for the viability of many fungal pathogens. Therefore, the β-1,3-glucan synthase complex represents an excellent and primary target structure for antifungal drugs. Fungal cell wall β-glucan is also an important pathogen-associated molecular pattern (PAMP). To hide from innate immunity, many fungal pathogens depend on the synthesis of cell wall α-glucan, which functions as a stealth molecule to mask the β-glucans itself or links other masking structures to the cell wall. Here, we review the current knowledge about the biosynthetic machineries that synthesize β-1,3-glucan, β-1,6-glucan, and α-1,3-glucan. We summarize the discovery of the synthases, major regulatory traits, and the impact of glucan synthesis deficiencies on the fungal organisms. Despite all efforts, many aspects of glucan synthesis remain yet unresolved, keeping research directed toward cell wall biogenesis an exciting and continuously challenging topic.
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Affiliation(s)
- Johannes Wagener
- Institut Für Hygiene Und Mikrobiologie, University of Würzburg, Würzburg, Germany. .,National Reference Center for Invasive Fungal Infections (NRZMyk), Jena, Germany.
| | - Kristina Striegler
- Institut Für Hygiene Und Mikrobiologie, University of Würzburg, Würzburg, Germany
| | - Nikola Wagener
- Department of Cell Biology, Medical Faculty, University of Munich, Martinsried, Germany
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20
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Hercyk BS, Onwubiko UN, Das ME. Coordinating septum formation and the actomyosin ring during cytokinesis in Schizosaccharomyces pombe. Mol Microbiol 2019; 112:1645-1657. [PMID: 31533197 PMCID: PMC6904431 DOI: 10.1111/mmi.14387] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2019] [Indexed: 01/08/2023]
Abstract
During cytokinesis, animal and fungal cells form a membrane furrow via actomyosin ring constriction. Our understanding of actomyosin ring-driven cytokinesis stems extensively from the fission yeast model system. However, unlike animal cells, actomyosin ring constriction occurs simultaneously with septum formation in fungi. While the formation of an actomyosin ring is essential for cytokinesis in fission yeast, proper furrow formation also requires septum deposition. The molecular mechanisms of spatiotemporal coordination of septum deposition with actomyosin ring constriction are poorly understood. Although the role of the actomyosin ring as a mechanical structure driving furrow formation is better understood, its role as a spatiotemporal landmark for septum deposition is not widely discussed. Here we review and discuss the recent advances describing how the actomyosin ring spatiotemporally regulates membrane traffic to promote septum-driven cytokinesis in fission yeast. Finally, we explore emerging questions in cytokinesis, and discuss the role of extracellular matrix during cytokinesis in other organisms.
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Affiliation(s)
- Brian S Hercyk
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Udo N Onwubiko
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Maitreyi E Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
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21
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Chang TH, Liu YW, Lin YH, Lin JJ, Huang JW, Hussain A, Chang PFL. Silver Nanoparticles on Nanoscale Silica Platelets (AgNP/NSP) and Nanoscale Silica Platelets (NSP) Inhibit the Development of Fusarium oxysporum f. sp. niveum. ACS APPLIED BIO MATERIALS 2019; 2:4978-4985. [PMID: 35021497 DOI: 10.1021/acsabm.9b00699] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nanotechnology has attracted much attention recently because of its agricultural applications. In this study, we analyzed the ability of two potential nanomaterials (NMs), nanoscale silica platelets (NSP) and silver nanoparticles on nanoscale silica platelets (AgNP/NSP), to control Fusarium wilt [caused by Fusarium oxysporum f. sp. niveum (Fon)] disease in watermelon. Both AgNP/NSP and NSP significantly reduced Fon mycelial growth and spore viability. In addition, AgNP/NSP decreased the mycelium viability at concentrations of 150 and 200 ppm. Scanning and transmission electron microscopy showed significant morphological effects on Fon cells, such as increased roughness and interior hollowing after AgNP/NSP and NSP treatments. Further, fluorescence staining experiments showed that a concomitant increase in membrane permeability occurred after treatment with NMs. The biochemical effects of NM treatment included a significant reduction in secreted cellulase activity. Interestingly, the addition of cysteine as a reducing agent decreased effects of NSP on Fon spores, suggesting suppression of Fon spore development attributable to oxidative stress. Taken together, these results indicate that AgNP/NSP and NSP may potentially serve as nanofungicides for future control of Fusarium wilt and other fungal diseases.
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Affiliation(s)
- Tao-Ho Chang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China.,Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China
| | - Yung-Wen Liu
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China
| | - Ying-Hong Lin
- Department of Plant Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan 91201, Republic of China
| | - Jiang-Jen Lin
- Institute of Polymer Science and Engineering, College of Engineering, National Taiwan University, Taipei, Taiwan 10617, Republic of China
| | - Jenn-Wen Huang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China.,Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China
| | - Adil Hussain
- Department of Agriculture, Abdul Wali Khan University Mardan, Mardan 23200, Pakistan
| | - Pi-Fang Linda Chang
- Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China.,Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China
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22
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Hercyk B, Das M. Rho Family GTPases in Fission Yeast Cytokinesis. Commun Integr Biol 2019; 12:171-180. [PMID: 31666919 PMCID: PMC6802929 DOI: 10.1080/19420889.2019.1678453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/20/2019] [Accepted: 09/23/2019] [Indexed: 12/22/2022] Open
Abstract
During cytokinesis, actomyosin ring constriction drives furrow formation. In animal cells, Rho GTPases drive this process through the positioning and assembly of the actomyosin ring, and through extracellular matrix remodeling within the furrow. In the fission yeast S. pombe, actomyosin ring constriction and septum formation are concurrent processes. While S. pombe is the primary source from which the mechanics of ring assembly and constriction stem, much less is known about the regulation of Rho GTPases that control these processes. Of the six Rho GTPases encoded in S. pombe, only Rho1, the RhoA homologue, has been shown to be essential for cytokinesis. While Rho3, Rho4, and Cdc42 have defined roles in cytokinesis, Rho2 and Rho5 play minor to no roles in this process. Here we review the roles of the Rho GTPases during cytokinesis, with a focus on their regulation, and discuss whether crosstalk between GTPases, as has been reported in other organisms, exists during cytokinesis in S. pombe.
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Affiliation(s)
- Brian Hercyk
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| | - Maitreyi Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
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23
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Ramos M, Cortés JCG, Sato M, Rincón SA, Moreno MB, Clemente-Ramos JÁ, Osumi M, Pérez P, Ribas JC. Two S. pombe septation phases differ in ingression rate, septum structure, and response to F-actin loss. J Cell Biol 2019; 218:4171-4194. [PMID: 31597680 PMCID: PMC6891078 DOI: 10.1083/jcb.201808163] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 04/19/2019] [Accepted: 09/10/2019] [Indexed: 12/28/2022] Open
Abstract
Ramos et al. establish that fission yeast septation proceeds in two phases. Initially, the septum is immature and, upon F-actin depolymerization, loses the Bgs1 glucan synthase and fails to ingress. During a second phase, the mature septum can maintain Bgs1 and ingression without F-actin, and ingression becomes Cdc42 and exocyst dependent. In fission yeast, cytokinesis requires a contractile actomyosin ring (CR) coupled to membrane and septum ingression. Septation proceeds in two phases. In anaphase B, the septum ingresses slowly. During telophase, the ingression rate increases, and the CR becomes dispensable. Here, we explore the relationship between the CR and septation by analyzing septum ultrastructure, ingression, and septation proteins in cells lacking F-actin. We show that the two phases of septation correlate with septum maturation and the response of cells to F-actin removal. During the first phase, the septum is immature and, following F-actin removal, rapidly loses the Bgs1 glucan synthase from the membrane edge and fails to ingress. During the second phase, the rapidly ingressing mature septum can maintain a Bgs1 ring and septum ingression without F-actin, but ingression becomes Cdc42 and exocyst dependent. Our results provide new insights into fungal cytokinesis and reveal the dual function of CR as an essential landmark for the concentration of Bgs1 and a contractile structure that maintains septum shape and synthesis.
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Affiliation(s)
- Mariona Ramos
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Salamanca, Spain
| | - Juan Carlos G Cortés
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Salamanca, Spain
| | - Mamiko Sato
- Laboratory of Electron Microscopy/Bio-imaging Center, Japan Women's University, Bunkyo-ku, Tokyo, Japan
| | - Sergio A Rincón
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Salamanca, Spain
| | - M Belén Moreno
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Salamanca, Spain
| | - José Ángel Clemente-Ramos
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Salamanca, Spain
| | - Masako Osumi
- Laboratory of Electron Microscopy/Bio-imaging Center, Japan Women's University, Bunkyo-ku, Tokyo, Japan.,Integrated Imaging Research Support, Chiyoda-ku, Tokyo, Japan
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Salamanca, Spain
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24
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Morris Z, Sinha D, Poddar A, Morris B, Chen Q. Fission yeast TRP channel Pkd2p localizes to the cleavage furrow and regulates cell separation during cytokinesis. Mol Biol Cell 2019; 30:1791-1804. [PMID: 31116668 PMCID: PMC6727746 DOI: 10.1091/mbc.e18-04-0270] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Force plays a central role in separating daughter cells during cytokinesis, the last stage of cell division. However, the mechanism of force sensing during cytokinesis remains unknown. Here we discovered that Pkd2p, a putative force-sensing transient receptor potential channel, localizes to the cleavage furrow during cytokinesis of the fission yeast, Schizosaccharomyces pombe. Pkd2p, whose human homologues are associated with autosomal polycystic kidney disease, is an essential protein whose localization depends on the contractile ring and the secretory pathway. We identified and characterized a novel pkd2 mutant pkd2-81KD. The pkd2 mutant cells show signs of osmotic stress, including temporary shrinking, paused turnover of the cytoskeletal structures, and hyperactivated mitogen-activated protein kinase signaling. During cytokinesis, although the contractile ring constricts more rapidly in the pkd2 mutant than the wild-type cells (50% higher), the cell separation in the mutant is slower and often incomplete. These cytokinesis defects are also consistent with misregulated turgor pressure. Finally, the pkd2 mutant exhibits strong genetic interactions with two mutants of the septation initiation network pathway, a signaling cascade essential for cytokinesis. We propose that Pkd2p modulates osmotic homeostasis and is potentially a novel regulator of cytokinesis.
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Affiliation(s)
- Zachary Morris
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Debatrayee Sinha
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Abhishek Poddar
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Brittni Morris
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Qian Chen
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
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25
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Ruiz-Herrera J, Ortiz-Castellanos L. Cell wall glucans of fungi. A review. ACTA ACUST UNITED AC 2019; 5:100022. [PMID: 32743138 PMCID: PMC7389562 DOI: 10.1016/j.tcsw.2019.100022] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 02/01/2019] [Accepted: 02/03/2019] [Indexed: 11/23/2022]
Abstract
Glucans are the most abundant compounds in the fungal cell walls. The most common type of glucose bonding is 1 → 3, both alpha and beta. Microfibrillar glucans with chitin provide rigidity to the fungal wall. Fungal beta glucans act as PAMPS during infection of animals and plants.
Glucans are the most abundant polysaccharides in the cell walls of fungi, and their structures are highly variable. Accordingly, their glucose moieties may be joined through either or both alpha (α) or beta (β) linkages, they are either lineal or branched, and amorphous or microfibrillar. Alpha 1,3 glucans sensu strictu (pseudonigerans) are the most abundant alpha glucans present in the cell walls of fungi, being restricted to dikarya. They exist in the form of structural microfibrils that provide resistance to the cell wall. The structure of beta glucans is more complex. They are linear or branched, and contain mostly β 1,3 and β 1,6 linkages, existing in the form of microfibrils. Together with chitin they constitute the most important structural components of fungal cell walls. They are the most abundant components of the cell walls in members of all fungal phyla, with the exception of Microsporidia, where they are absent. Taking into consideration the importance of glucans in the structure and physiology of the fungi, in the present review we describe the following aspects of these polysaccharides: i) types and distribution of fungal glucans, ii) their structure, iii) their roles, iv) the mechanism of synthesis of the most important ones, and v) the phylogentic relationships of the enzymes involved in their synthesis.
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Affiliation(s)
- José Ruiz-Herrera
- Departamento de Ingeniería Genética, Unidad Irapuato, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km. 9.6, Libramiento Norte, Carretera Irapuato-León, 36821 Irapuato, Gto. Mexico
| | - Lucila Ortiz-Castellanos
- Departamento de Ingeniería Genética, Unidad Irapuato, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km. 9.6, Libramiento Norte, Carretera Irapuato-León, 36821 Irapuato, Gto. Mexico
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26
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Okada H, Wloka C, Wu JQ, Bi E. Distinct Roles of Myosin-II Isoforms in Cytokinesis under Normal and Stressed Conditions. iScience 2019; 14:69-87. [PMID: 30928696 PMCID: PMC6441717 DOI: 10.1016/j.isci.2019.03.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 01/30/2019] [Accepted: 03/12/2019] [Indexed: 12/31/2022] Open
Abstract
To address the question of why more than one myosin-II isoform is expressed in a single cell to drive cytokinesis, we analyzed the roles of the myosin-II isoforms, Myo2 and Myp2, of the fission yeast Schizosaccharomyces pombe, in cytokinesis under normal and stressed conditions. We found that Myp2 controls the disassembly, stability, and constriction initiation of the Myo2 ring in response to high-salt stress. A C-terminal coiled-coil domain of Myp2 is required for its immobility and contractility during cytokinesis, and when fused to the tail of the dynamic Myo2, renders the chimera the low-turnover property. We also found, by following distinct processes in real time at the single-cell level, that Myo2 and Myp2 are differentially required but collectively essential for guiding extracellular matrix remodeling during cytokinesis. These results suggest that the dynamic and immobile myosin-II isoforms are evolved to carry out cytokinesis with robustness under different growth conditions. The myosin-II isoforms Myo2 and Myp2 display distinct responses to cellular stress Myp2 controls the constriction initiation of Myo2 during stress response A C-terminal region of Myp2 is required for its immobility during cytokinesis Myo2 and Myp2 are differentially required for guiding ECM remodeling during cytokinesis
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Affiliation(s)
- Hiroki Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Carsten Wloka
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA; Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AE Groningen, The Netherlands
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA.
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Onwubiko UN, Mlynarczyk PJ, Wei B, Habiyaremye J, Clack A, Abel SM, Das ME. A Cdc42 GEF, Gef1, through endocytosis organizes F-BAR Cdc15 along the actomyosin ring and promotes concentric furrowing. J Cell Sci 2019; 132:jcs223776. [PMID: 30709916 PMCID: PMC6432710 DOI: 10.1242/jcs.223776] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/21/2019] [Indexed: 01/17/2023] Open
Abstract
During cytokinesis, fission yeast coordinates actomyosin ring constriction with septum ingression, resulting in concentric furrow formation by a poorly defined mechanism. We report that Schizosaccharomyces pombe cells lacking the Cdc42 activator Gef1, combined with an activated allele of the formin, Cdc12, display non-concentric furrowing. Non-concentrically furrowing cells display uneven distribution of the scaffold Cdc15 along the ring. This suggests that, after ring assembly, uniform Cdc15 distribution along the ring enables proper furrow formation. We find that, after assembly, Cdc15 is recruited to the ring in an Arp2/3 complex-dependent manner and is decreased in the activated cdc12 mutant. Cdc15 at cortical endocytic patches shows increased levels and extended lifetimes in gef1 and activated cdc12 mutants. We hypothesize endocytosis helps recruit Cdc15 to assembled rings; uneven Cdc15 distribution at the ring occurs when endocytic patches contain increased Cdc15 levels and the patch-association rate is slow. Based on this, we developed a mathematical model that captures experimentally observed Cdc15 distributions along the ring. We propose that, at the ring, Gef1 and endocytic events promote uniform Cdc15 organization to enable proper septum ingression and concentric furrow formation.
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Affiliation(s)
- Udo N Onwubiko
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Paul J Mlynarczyk
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Bin Wei
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Julius Habiyaremye
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Amanda Clack
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Steven M Abel
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Maitreyi E Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
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Cortés JCG, Curto MÁ, Carvalho VSD, Pérez P, Ribas JC. The fungal cell wall as a target for the development of new antifungal therapies. Biotechnol Adv 2019; 37:107352. [PMID: 30797093 DOI: 10.1016/j.biotechadv.2019.02.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/23/2019] [Accepted: 02/16/2019] [Indexed: 12/17/2022]
Abstract
In the past three decades invasive mycoses have globally emerged as a persistent source of healthcare-associated infections. The cell wall surrounding the fungal cell opposes the turgor pressure that otherwise could produce cell lysis. Thus, the cell wall is essential for maintaining fungal cell shape and integrity. Given that this structure is absent in host mammalian cells, it stands as an important target when developing selective compounds for the treatment of fungal infections. Consequently, treatment with echinocandins, a family of antifungal agents that specifically inhibits the biosynthesis of cell wall (1-3)β-D-glucan, has been established as an alternative and effective antifungal therapy. However, the existence of many pathogenic fungi resistant to single or multiple antifungal families, together with the limited arsenal of available antifungal compounds, critically affects the effectiveness of treatments against these life-threatening infections. Thus, new antifungal therapies are required. Here we review the fungal cell wall and its relevance in biotechnology as a target for the development of new antifungal compounds, disclosing the most promising cell wall inhibitors that are currently in experimental or clinical development for the treatment of some invasive mycoses.
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Affiliation(s)
- Juan Carlos G Cortés
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
| | - M-Ángeles Curto
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Vanessa S D Carvalho
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
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29
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Kwon L, Magee EM, Crayton A, Goss JW. Fission yeast type 2 node proteins Blt1p and Gef2p cooperate to ensure timely completion of cytokinesis. BMC Mol Cell Biol 2019; 20:1. [PMID: 31041892 PMCID: PMC6446504 DOI: 10.1186/s12860-018-0182-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 12/14/2018] [Indexed: 12/01/2022] Open
Abstract
Background The conserved NDR-family kinase Sid2p localizes to the contractile ring during fission yeast cytokinesis to promote ring constriction, septation, and completion of cell division. Previous studies have found that the Type 2 interphase node proteins Blt1p and Gef2p contribute to localization of Sid2p and its regulatory protein Mob1p at the division site. However, their relative contributions and whether they operate in the same or parallel pathways has been unclear. In this study, we quantify the respective roles of Blt1p and Gef2p in Sid2p/Mob1p recruitment and characterize the effect of single and double deletion mutants on contractile ring dynamics and completion of cell division. Results Using quantitative confocal fluorescence microscopy, we measured Sid2p and Mob1p recruitment to the division site in blt1∆, gef2∆, and blt1∆/gef2∆ mutant cells. We observed an equivalent decrease in Sid2p/Mob1p localization for both single and double mutants. Though assembly of the contractile ring is normal in these mutants, the reduction in Sid2p/Mob1p at the division site delayed the onset of contractile ring constriction and completion of division. We quantified localization of Blt1p and Gef2p at the medial cortex throughout the cell cycle and found that Blt1p localization to interphase nodes and the contractile ring is independent of Gef2p. However, Gef2p localization to the contractile ring is decreased in blt1∆ mutants. Conclusions Blt1p and Gef2p work in the same pathway, rather than in parallel, to localize the NDR-family kinase Sid2p and its regulatory partner Mob1p to the division site, thereby promoting timely completion of cell division. Future studies are necessary to understand how additional fission yeast cytokinesis proteins work with these Type 2 interphase node components to promote Sid2p/Mob1p recruitment. Electronic supplementary material The online version of this article (10.1186/s12860-018-0182-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lois Kwon
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA, 02481, USA
| | - Emma M Magee
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA, 02481, USA
| | - Alexis Crayton
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA, 02481, USA
| | - John W Goss
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA, 02481, USA.
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O’Shaughnessy B, Thiyagarajan S. Mechanisms of contractile ring tension production and constriction. Biophys Rev 2018; 10:1667-1681. [PMID: 30456601 PMCID: PMC6297097 DOI: 10.1007/s12551-018-0476-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 10/23/2018] [Indexed: 12/24/2022] Open
Abstract
The contractile ring is a remarkable tension-generating cellular machine that constricts and divides cells into two during cytokinesis, the final stage of the cell cycle. Since the ring's discovery, the parallels with muscle have been emphasized. Both are contractile actomyosin machineries, and long ago, a muscle-like sliding filament mechanism was proposed for the ring. This review focuses on the mechanisms that generate ring tension and constrict contractile rings. The emphasis is on fission yeast, whose contractile ring is sufficiently well characterized that realistic mathematical models are feasible, and possible lessons from fission yeast that may apply to animal cells are discussed. Recent discoveries relevant to the organization in fission yeast rings suggest a stochastic steady-state version of the classic sliding filament mechanism for tension. The importance of different modes of anchoring for tension production and for organizational stability of constricting rings is discussed. Possible mechanisms are discussed that set the constriction rate and enable the contractile ring to meet the technical challenge of maintaining structural integrity and tension-generating capacity while continuously disassembling throughout constriction.
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Affiliation(s)
- Ben O’Shaughnessy
- Department of Chemical Engineering, Columbia University, New York, NY 10027 USA
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31
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Pérez P, Cortés JC, Cansado J, Ribas JC. Fission yeast cell wall biosynthesis and cell integrity signalling. ACTA ACUST UNITED AC 2018; 4:1-9. [PMID: 32743131 PMCID: PMC7388972 DOI: 10.1016/j.tcsw.2018.10.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/04/2018] [Accepted: 10/09/2018] [Indexed: 02/02/2023]
Abstract
The cell wall is a structure external to the plasma membrane that is essential for the survival of the fungi. This polysaccharidic structure confers resistance to the cell internal turgor pressure and protection against mechanical injury. The fungal wall is also responsible for the shape of these organisms due to different structural polysaccharides, such as β-(1,3)-glucan, which form fibers and confer rigidity to the cell wall. These polysaccharides are not present in animal cells and therefore they constitute excellent targets for antifungal chemotherapies. Cell wall damage leads to the activation of MAPK signaling pathways, which respond to the damage by activating the repair of the wall and the maintenance of the cell integrity. Fission yeast Schizosaccharomyces pombe is a model organism for the study morphogenesis, cell wall, and how different inputs might regulate this structure. We present here a short overview of the fission yeast wall composition and provide information about the main biosynthetic activities that assemble this cell wall. Additionally, we comment the recent advances in the knowledge of the cell wall functions and discuss the role of the cell integrity MAPK signaling pathway in the regulation of fission yeast wall.
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Affiliation(s)
- Pilar Pérez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas and Universidad de Salamanca, 37007 Salamanca, Spain
- Corresponding author.
| | - Juan C.G. Cortés
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas and Universidad de Salamanca, 37007 Salamanca, Spain
| | - Jose Cansado
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, 30071 Murcia, Spain
| | - Juan C. Ribas
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas and Universidad de Salamanca, 37007 Salamanca, Spain
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32
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Dey SK, Pollard TD. Involvement of the septation initiation network in events during cytokinesis in fission yeast. J Cell Sci 2018; 131:jcs.216895. [PMID: 30072443 DOI: 10.1242/jcs.216895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 07/23/2018] [Indexed: 10/28/2022] Open
Abstract
The septation initiation network (SIN), comprising a GTPase and a cascade of three protein kinases, regulates cell division in fission yeast Schizosaccharomyces pombe, but questions remain about its influence on cytokinesis. Here, we made quantitative measurements of the numbers of Cdc7p kinase molecules (a marker for SIN activity) on spindle pole bodies (SPBs), and on the timing of assembly, maturation and constriction of contractile rings via six different proteins tagged with fluorescent proteins. When SIN activity is low in spg1-106 mutant cells at 32°C, cytokinetic nodes formed contractile rings ∼3 min slower than wild-type cells. During the maturation period, these rings maintained normal levels of the myosin-II mEGFP-Myo2p but accumulated less of the F-BAR protein Cdc15p-GFP than in wild-type cells. The Cdc15p-GFP fluorescence then disintegrated into spots as mEGFP-Myo2p dissociated slowly. Some rings started to constrict at the normal time, but most failed to complete constriction. When high SIN activity persists far longer than normal on both SPBs in cdc16-116 mutant cells at 32°C, contractile rings assembled and constricted normally, but disassembled slowly, delaying cell separation.
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Affiliation(s)
- Sumit K Dey
- Department of Molecular Cellular and Developmental Biology, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA
| | - Thomas D Pollard
- Department of Molecular Cellular and Developmental Biology, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA .,Department of Molecular Biophysics and Biochemistry, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA.,Department of Cell Biology, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA
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33
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G. Cortés JC, Ramos M, Konomi M, Barragán I, Moreno MB, Alcaide-Gavilán M, Moreno S, Osumi M, Pérez P, Ribas JC. Specific detection of fission yeast primary septum reveals septum and cleavage furrow ingression during early anaphase independent of mitosis completion. PLoS Genet 2018; 14:e1007388. [PMID: 29813053 PMCID: PMC5993333 DOI: 10.1371/journal.pgen.1007388] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 06/08/2018] [Accepted: 05/01/2018] [Indexed: 11/27/2022] Open
Abstract
It is widely accepted in eukaryotes that the cleavage furrow only initiates after mitosis completion. In fission yeast, cytokinesis requires the synthesis of a septum tightly coupled to cleavage furrow ingression. The current cytokinesis model establishes that simultaneous septation and furrow ingression only initiate after spindle breakage and mitosis exit. Thus, this model considers that although Cdk1 is inactivated at early-anaphase, septation onset requires the long elapsed time until mitosis completion and full activation of the Hippo-like SIN pathway. Here, we studied the precise timing of septation onset regarding mitosis by exploiting both the septum-specific detection with the fluorochrome calcofluor and the high-resolution electron microscopy during anaphase and telophase. Contrarily to the existing model, we found that both septum and cleavage furrow start to ingress at early anaphase B, long before spindle breakage, with a slow ingression rate during anaphase B, and greatly increasing after telophase onset. This shows that mitosis and cleavage furrow ingression are not concatenated but simultaneous events in fission yeast. We found that the timing of septation during early anaphase correlates with the cell size and is regulated by the corresponding levels of SIN Etd1 and Rho1. Cdk1 inactivation was directly required for timely septation in early anaphase. Strikingly the reduced SIN activity present after Cdk1 loss was enough to trigger septation by immediately inducing the medial recruitment of the SIN kinase complex Sid2-Mob1. On the other hand, septation onset did not depend on the SIN asymmetry establishment, which is considered a hallmark for SIN activation. These results recalibrate the timing of key cytokinetic events in fission yeast; and unveil a size-dependent control mechanism that synchronizes simultaneous nuclei separation with septum and cleavage furrow ingression to safeguard the proper chromosome segregation during cell division. Fission yeast cytokinesis requires the invagination of the equatorial plasma membrane (cleavage furrow ingression) coupled to the synthesis of a special wall structure named septum (septation). Despite Cdk1 kinase is inactivated in early anaphase, it is believed that cleavage furrow ingression and septation onset require anaphase progression and mitosis completion, only initiating after the complete activation of the Hippo-like septation initiation network (SIN) after telophase onset. Here, we studied the precise timing of septation start with respect to mitosis through specific septum-staining and electron microscopy. We found that septum and cleavage furrow ingression initiate in early anaphase, showing first a slow ingression rate during anaphase B, and increasing to a fast ingression rate after telophase onset. Thus, mitosis and cleavage furrow ingression are not concatenated but simultaneous events in fission yeast. The timing of septation correlated with cell size and depended on the level of cytoplasmic activators like SIN Etd1 and Rho1. We further analyzed the mitotic mechanisms that control the septation onset during early anaphase. Cdk1 directly regulated the timing of septation onset during early anaphase, and the low SIN activity present after Cdk1 inactivation was enough to trigger septation. Globally, these results recalibrate the timing of the main cytokinetic events of fission yeast and reveal a size-dependent control mechanism that synchronizes simultaneous nuclei separation with septum and cleavage furrow ingression.
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Affiliation(s)
- Juan Carlos G. Cortés
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
- * E-mail:
| | - Mariona Ramos
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - Mami Konomi
- Laboratory of Electron Microscopy/Bio-imaging Centre, and Department of Chemical and Biological Sciences, Japan Women's University, Mejirodai, Bunkyo-ku, Tokyo, Japan
| | - Iris Barragán
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - M. Belén Moreno
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - María Alcaide-Gavilán
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/Consejo Superior de Investigaciones Científicas, Sevilla, Spain
| | - Sergio Moreno
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - Masako Osumi
- Laboratory of Electron Microscopy/Bio-imaging Centre, and Department of Chemical and Biological Sciences, Japan Women's University, Mejirodai, Bunkyo-ku, Tokyo, Japan
- NPO: Integrated Imaging Research Support, Hirakawa-cho, Chiyoda-ku, Tokyo, Japan
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
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34
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Abstract
The Schizosaccharomyces pombe cell wall is a rigid exoskeletal structure mainly composed of interlinked glucose polysaccharides and galactomannoproteins. It is essential for survival of the fission yeast, as it prevents cells from bursting from internal turgor pressure and protects them from mechanical injuries. Additionally, the cell wall determines the cell shape and, therefore, a better knowledge of cell wall structure and composition could provide valuable data in S. pombe morphogenetic studies. Here, we provide information about this structure and the current reliable methods for rapid analysis of the cell wall polymers by specific enzymatic and chemical degradations of purified cell walls.
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Affiliation(s)
- Pilar Pérez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, 37007 Salamanca, Spain
| | - Juan C Ribas
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, 37007 Salamanca, Spain
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35
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Wei B, Hercyk BS, Habiyaremye J, Das M. Spatiotemporal Analysis of Cytokinetic Events in Fission Yeast. J Vis Exp 2017. [PMID: 28287547 DOI: 10.3791/55109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cytokinesis, the final step in cell division is critical for maintaining genome integrity. Proper cytokinesis is important for cell differentiation and development. Cytokinesis involves a series of events that are well coordinated in time and space. Cytokinesis involves the formation of an actomyosin ring at the division site, followed by ring constriction, membrane furrow formation and extra cellular matrix remodeling. The fission yeast, Schizosaccharomyces pombe (S. pombe) is a well-studied model system that has revealed with substantial clarity the initial events in cytokinesis. However, we do not understand clearly how different cytokinetic events are coordinated spatiotemporally. To determine this, one needs to analyze the different cytokinetic events in great details in both time and in space. Here we describe a microscopy approach to examine different cytokinetic events in live cells. With this approach it is possible to time different cytokinetic events and determine the time of recruitment of different proteins during cytokinesis. In addition, we describe protocols to compare protein localization, and distribution at the site of cell division. This is a basic protocol to study cytokinesis in fission yeast and can also be used for other yeasts and fungal systems.
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Affiliation(s)
- Bin Wei
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee
| | - Brian S Hercyk
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee
| | - Julius Habiyaremye
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee
| | - Maitreyi Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee;
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36
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Davidson R, Pontasch JA, Wu JQ. Sbg1 Is a Novel Regulator for the Localization of the β-Glucan Synthase Bgs1 in Fission Yeast. PLoS One 2016; 11:e0167043. [PMID: 27898700 PMCID: PMC5127554 DOI: 10.1371/journal.pone.0167043] [Citation(s) in RCA: 16] [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: 07/24/2016] [Accepted: 11/08/2016] [Indexed: 02/03/2023] Open
Abstract
Glucan synthases synthesize glucans, complex polysaccharides that are the major components in fungal cell walls and division septa. Studying regulation of glucan synthases is important as they are essential for fungal cell survival and thus popular targets for anti-fungal drugs. Linear 1,3-β-glucan is the main component of primary septum and is synthesized by the conserved β-glucan synthase Bgs1 in fission yeast cytokinesis. It is known that Rho1 GTPase regulates Bgs1 catalytic activity and the F-BAR protein Cdc15 plays a role in Bgs1 delivery to the plasma membrane. Here we characterize a novel protein Sbg1 that is present in a complex with Bgs1 and regulates its protein levels and localization. Sbg1 is essential for contractile-ring constriction and septum formation during cytokinesis. Sbg1 and Bgs1 physically interact and are interdependent for localization to the plasma membrane. Bgs1 is less stable and/or mis-targeted to vacuoles in sbg1 mutants. Moreover, Sbg1 plays an earlier and more important role in Bgs1 trafficking and localization than Cdc15. Together, our data reveal a new mode of regulation for the essential β-glucan synthase Bgs1 by the novel protein Sbg1.
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Affiliation(s)
- Reshma Davidson
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Josef A. Pontasch
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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37
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Sethi K, Palani S, Cortés JCG, Sato M, Sevugan M, Ramos M, Vijaykumar S, Osumi M, Naqvi NI, Ribas JC, Balasubramanian M. A New Membrane Protein Sbg1 Links the Contractile Ring Apparatus and Septum Synthesis Machinery in Fission Yeast. PLoS Genet 2016; 12:e1006383. [PMID: 27749909 PMCID: PMC5066963 DOI: 10.1371/journal.pgen.1006383] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 09/23/2016] [Indexed: 01/14/2023] Open
Abstract
Cytokinesis in many organisms requires a plasma membrane anchored actomyosin ring, whose contraction facilitates cell division. In yeast and fungi, actomyosin ring constriction is also coordinated with division septum assembly. How the actomyosin ring interacts with the plasma membrane and the plasma membrane-localized septum synthesizing machinery remains poorly understood. In Schizosaccharomyces pombe, an attractive model organism to study cytokinesis, the β-1,3-glucan synthase Cps1p / Bgs1p, an integral membrane protein, localizes to the plasma membrane overlying the actomyosin ring and is required for primary septum synthesis. Through a high-dosage suppressor screen we identified an essential gene, sbg1+ (suppressor of beta glucan synthase 1), which suppressed the colony formation defect of Bgs1-defective cps1-191 mutant at higher temperatures. Sbg1p, an integral membrane protein, localizes to the cell ends and to the division site. Sbg1p and Bgs1p physically interact and are dependent on each other to localize to the division site. Loss of Sbg1p results in an unstable actomyosin ring that unravels and slides, leading to an inability to deposit a single contiguous division septum and an important reduction of the β-1,3-glucan proportion in the cell wall, coincident with that observed in the cps1-191 mutant. Sbg1p shows genetic and / or physical interaction with Rga7p, Imp2p, Cdc15p, and Pxl1p, proteins known to be required for actomyosin ring integrity and efficient septum synthesis. This study establishes Sbg1p as a key member of a group of proteins that link the plasma membrane, the actomyosin ring, and the division septum assembly machinery in fission yeast. Cell division in many organisms requires the function of an actomyosin ring, an apparatus that resembles the force generating machinery in the muscle. This ring apparatus is attached to the cell periphery (cell membranes) such that when it contracts, it brings the cell periphery together with it, leading to cell division. How the actomyosin ring is attached to the cell membrane at the division site is unknown. In this manuscript, we identify and describe Sbg1, a protein that links the actomyosin ring and the cell membranes since Sbg1 has a sequence that allows it to be inserted into the cell membrane. Sbg1 specifically localizes to the cell division site and also cooperates with a cell wall biosynthetic enzyme Bgs1 to achieve cell division. Consistently, in the absence of Sbg1, cells fail to divide leading to lethality. Sbg1 interacts with a number of cell division proteins, such as Cdc15, Rga7, Imp2, and Pxl1, to achieve its function as a bridge between the cell membrane and the actomyosin ring. Our work identifies a direct molecular link between the actomyosin ring and the cell membranes, explaining how ring contraction leads to inward movement of the cell periphery.
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Affiliation(s)
- Kriti Sethi
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Saravanan Palani
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Juan C. G. Cortés
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Cinetificas/Universidad de Salamanca, Salamanca, Spain
| | - Mamiko Sato
- Laboratory of Electron Microscopy/Bio-imaging Centre, and Department of Chemical and Biological Sciences, Faculty of Sciences, Japan Women’s University, Mejirodai, Bunkyo-ku, Tokyo, Japan
| | - Mayalagu Sevugan
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore
| | - Mariona Ramos
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Cinetificas/Universidad de Salamanca, Salamanca, Spain
| | - Shruthi Vijaykumar
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Masako Osumi
- Laboratory of Electron Microscopy/Bio-imaging Centre, and Department of Chemical and Biological Sciences, Faculty of Sciences, Japan Women’s University, Mejirodai, Bunkyo-ku, Tokyo, Japan
- NPO Integrated Imaging Research Support, Hirakawa-cho, Chiyoda-ku, Tokyo, Japan
| | - Naweed I. Naqvi
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Cinetificas/Universidad de Salamanca, Salamanca, Spain
| | - Mohan Balasubramanian
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
- * E-mail:
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Abstract
In animal cells, cytokinesis requires the formation of a cleavage furrow that divides the cell into two daughter cells. Furrow formation is achieved by constriction of an actomyosin ring that invaginates the plasma membrane. However, fungal cells contain a rigid extracellular cell wall surrounding the plasma membrane; thus, fungal cytokinesis also requires the formation of a special septum wall structure between the dividing cells. The septum biosynthesis must be strictly coordinated with the deposition of new plasma membrane material and actomyosin ring closure and must occur in such a way that no breach in the cell wall occurs at any time. Because of the high turgor pressure in the fungal cell, even a minor local defect might lead to cell lysis and death. Here we review our knowledge of the septum structure in the fission yeast Schizosaccharomyces pombe and of the recent advances in our understanding of the relationship between septum biosynthesis and actomyosin ring constriction and how the two collaborate to build a cross-walled septum able to support the high turgor pressure of the cell. In addition, we discuss the importance of the septum biosynthesis for the steady ingression of the cleavage furrow.
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Liu Y, Lee IJ, Sun M, Lower CA, Runge KW, Ma J, Wu JQ. Roles of the novel coiled-coil protein Rng10 in septum formation during fission yeast cytokinesis. Mol Biol Cell 2016; 27:2528-41. [PMID: 27385337 PMCID: PMC4985255 DOI: 10.1091/mbc.e16-03-0156] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/21/2016] [Indexed: 12/31/2022] Open
Abstract
The regulation of Rho-GAP localization is not well understood. A novel coiled-coil protein Rng10 is characterized that localizes the Rho-GAP Rga7 in fission yeast. Rng10 and Rga7 physically interact and work together to regulate the accumulation and dynamics of glucan synthases for successful septum formation during cytokinesis. Rho GAPs are important regulators of Rho GTPases, which are involved in various steps of cytokinesis and other processes. However, regulation of Rho-GAP cellular localization and function is not fully understood. Here we report the characterization of a novel coiled-coil protein Rng10 and its relationship with the Rho-GAP Rga7 in fission yeast. Both rng10Δ and rga7Δ result in defective septum and cell lysis during cytokinesis. Rng10 and Rga7 colocalize on the plasma membrane at the cell tips during interphase and at the division site during cell division. Rng10 physically interacts with Rga7 in affinity purification and coimmunoprecipitation. Of interest, Rga7 localization is nearly abolished without Rng10. Moreover, Rng10 and Rga7 work together to regulate the accumulation and dynamics of glucan synthases for successful septum formation in cytokinesis. Our results show that cellular localization and function of the Rho-GAP Rga7 are regulated by a novel protein, Rng10, during cytokinesis in fission yeast.
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Affiliation(s)
- Yajun Liu
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - I-Ju Lee
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Mingzhai Sun
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Casey A Lower
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Kurt W Runge
- Department of Molecular Genetics, Cleveland Clinic Lerner College of Medicine, Cleveland, OH 44195
| | - Jianjie Ma
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210
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40
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Cortés JCG, Ramos M, Osumi M, Pérez P, Ribas JC. Fission yeast septation. Commun Integr Biol 2016; 9:e1189045. [PMID: 27574536 PMCID: PMC4988442 DOI: 10.1080/19420889.2016.1189045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 05/03/2016] [Accepted: 05/06/2016] [Indexed: 11/09/2022] Open
Abstract
In animal cells cytokinesis relies on the contraction of an actomyosin ring that pulls the plasma membrane to create a cleavage furrow, whose ingression finally divides the mother cell into two daughter cells. Fungal cells are surrounded by a tough and flexible structure called cell wall, which is considered to be the functional equivalent of the extracellular matrix in animal cells. Therefore, in addition to cleavage furrow ingression, fungal cytokinesis also requires the centripetal formation of a septum wall structure that develops between the dividing cells, whose genesis must be strictly coordinated with both the actomyosin ring closure and plasma membrane ingression. Here we briefly review what is known about the septum structure and composition in the fission yeast Schizosaccharomyces pombe, the recent progress about the relationship between septum biosynthesis and actomyosin ring constriction, and the importance of the septum and ring in the steady progression of the cleavage furrow.
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Affiliation(s)
- Juan C G Cortés
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca , Salamanca, Spain
| | - Mariona Ramos
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca , Salamanca, Spain
| | - Masako Osumi
- Faculty of Science, Laboratory of Electron Microscopy, Japan Women's University, Tokyo, Japan; Integrated Imaging Research Support, Tokyo, Japan
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca , Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca , Salamanca, Spain
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41
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Wei B, Hercyk BS, Mattson N, Mohammadi A, Rich J, DeBruyne E, Clark MM, Das M. Unique spatiotemporal activation pattern of Cdc42 by Gef1 and Scd1 promotes different events during cytokinesis. Mol Biol Cell 2016; 27:1235-45. [PMID: 26941334 PMCID: PMC4831878 DOI: 10.1091/mbc.e15-10-0700] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/23/2016] [Indexed: 11/11/2022] Open
Abstract
The Rho-family GTPase Cdc42 regulates cell polarity and localizes to the cell division site. Cdc42 is activated by guanine nucleotide exchange factors (GEFs). We report that Cdc42 promotes cytokinesis via a unique spatiotemporal activation pattern due to the distinct action of its GEFs, Gef1 and Scd1, in fission yeast. Before cytokinetic ring constriction, Cdc42 activation, is Gef1 dependent, and after ring constriction, it is Scd1 dependent. Gef1 localizes to the actomyosin ring immediately after ring assembly and promotes timely onset of ring constriction. Gef1 is required for proper actin organization during cytokinesis, distribution of type V myosin Myo52 to the division site, and timely recruitment of septum protein Bgs1. In contrast, Scd1 localizes to the broader region of ingressing membrane during cytokinetic furrowing. Scd1 promotes normal septum formation, andscd1Δcells display aberrant septa with reduced Bgs1 localization. Thus we define unique roles of the GEFs Gef1 and Scd1 in the regulation of distinct events during cytokinesis. Gef1 localizes first to the cytokinetic ring and promotes timely constriction, whereas Scd1 localizes later to the ingressing membrane and promotes septum formation. Our findings are consistent with reports that complexity in GTPase signaling patterns enables exquisite precision over the control of cellular processes.
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Affiliation(s)
- Bin Wei
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Brian S Hercyk
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Nicholas Mattson
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Ahmad Mohammadi
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Julie Rich
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Erica DeBruyne
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Mikayla M Clark
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
| | - Maitreyi Das
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996
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42
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Rincon SA, Paoletti A. Molecular control of fission yeast cytokinesis. Semin Cell Dev Biol 2016; 53:28-38. [PMID: 26806637 DOI: 10.1016/j.semcdb.2016.01.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/06/2016] [Indexed: 12/29/2022]
Abstract
Cytokinesis gives rise to two independent daughter cells at the end of the cell division cycle. The fission yeast Schizosaccharomyces pombe has emerged as one of the most powerful systems to understand how cytokinesis is controlled molecularly. Like in most eukaryotes, fission yeast cytokinesis depends on an acto-myosin based contractile ring that assembles at the division site under the control of spatial cues that integrate information on cell geometry and the position of the mitotic apparatus. Cytokinetic events are also tightly coordinated with nuclear division by the cell cycle machinery. These spatial and temporal regulations ensure an equal cleavage of the cytoplasm and an accurate segregation of the genetic material in daughter cells. Although this model system has specificities, the basic mechanisms of contractile ring assembly and function deciphered in fission yeast are highly valuable to understand how cytokinesis is controlled in other organisms that rely on a contractile ring for cell division.
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Affiliation(s)
- Sergio A Rincon
- Institut Curie, Centre de Recherche, PSL Research University, F-75248 Paris, France; CNRS UMR144, F-75248 Paris, France
| | - Anne Paoletti
- Institut Curie, Centre de Recherche, PSL Research University, F-75248 Paris, France; CNRS UMR144, F-75248 Paris, France.
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43
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García R, Botet J, Rodríguez-Peña JM, Bermejo C, Ribas JC, Revuelta JL, Nombela C, Arroyo J. Genomic profiling of fungal cell wall-interfering compounds: identification of a common gene signature. BMC Genomics 2015; 16:683. [PMID: 26341223 PMCID: PMC4560923 DOI: 10.1186/s12864-015-1879-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 08/25/2015] [Indexed: 01/01/2023] Open
Abstract
Background The fungal cell wall forms a compact network whose integrity is essential for cell morphology and viability. Thus, fungal cells have evolved mechanisms to elicit adequate adaptive responses when cell wall integrity (CWI) is compromised. Functional genomic approaches provide a unique opportunity to globally characterize these adaptive mechanisms. To provide a global perspective on these CWI regulatory mechanisms, we developed chemical-genomic profiling of haploid mutant budding yeast cells to systematically identify in parallel those genes required to cope with stresses interfering the cell wall by different modes of action: β-1,3 glucanase and chitinase activities (zymolyase), inhibition of β-1,3 glucan synthase (caspofungin) and binding to chitin (Congo red). Results Measurement of the relative fitness of the whole collection of 4786 haploid budding yeast knock-out mutants identified 222 mutants hypersensitive to caspofungin, 154 mutants hypersensitive to zymolyase, and 446 mutants hypersensitive to Congo red. Functional profiling uncovered both common and specific requirements to cope with different cell wall damages. We identified a cluster of 43 genes highly important for the integrity of the cell wall as the common “signature of cell wall maintenance (CWM)”. This cluster was enriched in genes related to vesicular trafficking and transport, cell wall remodeling and morphogenesis, transcription and chromatin remodeling, signal transduction and RNA metabolism. Although the CWI pathway is the main MAPK pathway regulating cell wall integrity, the collaboration with other signal transduction pathways like the HOG pathway and the invasive growth pathway is also required to cope with the cell wall damage depending on the nature of the stress. Finally, 25 mutant strains showed enhanced caspofungin resistance, including 13 that had not been previously identified. Only three of them, wsc1Δ, elo2Δ and elo3Δ, showed a significant decrease in β-1,3-glucan synthase activity. Conclusions This work provides a global perspective about the mechanisms involved in cell wall stress adaptive responses and the cellular functions required for cell wall integrity. The results may be useful to uncover new potential antifungal targets and develop efficient antifungal strategies by combination of two drugs, one targeting the cell wall and the other interfering with the adaptive mechanisms. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1879-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Raúl García
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, 28040, Madrid, Spain.
| | - Javier Botet
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
| | - José Manuel Rodríguez-Peña
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, 28040, Madrid, Spain.
| | - Clara Bermejo
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, 28040, Madrid, Spain.
| | - Juan Carlos Ribas
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain. .,Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, 37007, Salamanca, Spain.
| | - José Luis Revuelta
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
| | - César Nombela
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, 28040, Madrid, Spain.
| | - Javier Arroyo
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, 28040, Madrid, Spain.
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44
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Mechanics and morphogenesis of fission yeast cells. Curr Opin Microbiol 2015; 28:36-45. [PMID: 26291501 DOI: 10.1016/j.mib.2015.07.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/15/2015] [Accepted: 07/17/2015] [Indexed: 12/11/2022]
Abstract
The integration of biochemical and biomechanical elements is at the heart of morphogenesis. While animal cells are relatively soft objects which shape and mechanics is mostly regulated by cytoskeletal networks, walled cells including those of plants, fungi and bacteria are encased in a rigid cell wall which resist high internal turgor pressure. How these particular mechanical properties may influence basic cellular processes, such as growth, shape and division remains poorly understood. Recent work using the model fungal cell fission yeast, Schizosaccharomyces pombe, highlights important contribution of cell mechanics to various morphogenesis processes. We envision this genetically tractable system to serve as a novel standard for the mechanobiology of walled cell.
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45
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G. Cortés JC, Pujol N, Sato M, Pinar M, Ramos M, Moreno B, Osumi M, Ribas JC, Pérez P. Cooperation between Paxillin-like Protein Pxl1 and Glucan Synthase Bgs1 Is Essential for Actomyosin Ring Stability and Septum Formation in Fission Yeast. PLoS Genet 2015; 11:e1005358. [PMID: 26132084 PMCID: PMC4489101 DOI: 10.1371/journal.pgen.1005358] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 06/13/2015] [Indexed: 01/19/2023] Open
Abstract
In fungal cells cytokinesis requires coordinated closure of a contractile actomyosin ring (CAR) and synthesis of a special cell wall structure known as the division septum. Many CAR proteins have been identified and characterized, but how these molecules interact with the septum synthesis enzymes to form the septum remains unclear. Our genetic study using fission yeast shows that cooperation between the paxillin homolog Pxl1, required for ring integrity, and Bgs1, the enzyme responsible for linear β(1,3)glucan synthesis and primary septum formation, is required for stable anchorage of the CAR to the plasma membrane before septation onset, and for cleavage furrow formation. Thus, lack of Pxl1 in combination with Bgs1 depletion, causes failure of ring contraction and lateral cell wall overgrowth towards the cell lumen without septum formation. We also describe here that Pxl1 concentration at the CAR increases during cytokinesis and that this increase depends on the SH3 domain of the F-BAR protein Cdc15. In consequence, Bgs1 depletion in cells carrying a cdc15ΔSH3 allele causes ring disassembly and septation blockage, as it does in cells lacking Pxl1. On the other hand, the absence of Pxl1 is lethal when Cdc15 function is affected, generating a large sliding of the CAR with deposition of septum wall material along the cell cortex, and suggesting additional functions for both Pxl1 and Cdc15 proteins. In conclusion, our findings indicate that CAR anchorage to the plasma membrane through Cdc15 and Pxl1, and concomitant Bgs1 activity, are necessary for CAR maintenance and septum formation in fission yeast. Cytokinesis requires assembly of an actomyosin ring adjacent to the plasma membrane, which upon contraction pulls the membrane to form a cleavage furrow. In fungi ring closure is coordinated with the synthesis of a cell wall septum. Knowledge about the molecules anchoring the ring to the membrane is very limited. We have found that fission yeast paxillin, located at the ring, and Bgs1, the enzyme responsible for primary septum formation, located at the membrane, cooperate during cytokinesis. Both are required to anchor the ring to the membrane and to maintain it during cytokinesis. Moreover, both proteins cooperate to form the septum. Accordingly, paxillin is essential when Bgs1 is depleted. When both proteins are missing, the contractile ring forms but the lateral cell wall overgrows inwards without a defined cleavage furrow and septum formation. During cytokinesis there is an increase of paxillin which depends on the SH3 domain of the F-BAR protein Cdc15. Consequently the absence of this domain mimics the phenotype of paxillin absence in Bgs1-depleted cells. Interestingly, a decreased function of both Cdc15 and paxillin uncouples the septum synthesis from the ring contraction, indicating an essential cooperation between these proteins and Bgs1 for proper cytokinesis.
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Affiliation(s)
- Juan C. G. Cortés
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
- * E-mail:
| | - Nuria Pujol
- Department of Ciències Mèdiques, Bàsiques,Institut de Recerca Biomèdica (IRB) de Lleida, Faculty of Medicine, University of Lleida, Lleida, Spain
| | - Mamiko Sato
- Laboratory of Electron Microscopy/Open Research Centre, and Department of Chemical and Biological Sciences, Japan Women’s University, Mejirodai, Bunkyo-ku, Tokyo, Japan
| | - Mario Pinar
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Mariona Ramos
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - Belén Moreno
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - Masako Osumi
- Laboratory of Electron Microscopy/Open Research Centre, and Department of Chemical and Biological Sciences, Japan Women’s University, Mejirodai, Bunkyo-ku, Tokyo, Japan
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas (CSIC) / Universidad de Salamanca, Salamanca, Spain
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Dudin O, Bendezú FO, Groux R, Laroche T, Seitz A, Martin SG. A formin-nucleated actin aster concentrates cell wall hydrolases for cell fusion in fission yeast. ACTA ACUST UNITED AC 2015; 208:897-911. [PMID: 25825517 PMCID: PMC4384723 DOI: 10.1083/jcb.201411124] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The formin Fus1 nucleates a novel actin structure in fission yeast, named the actin fusion focus, which consists of an aster of actin filaments whose barbed ends are focalized at a membrane proximal site and serves to focalize cell wall hydrolase delivery for cell fusion. Cell–cell fusion is essential for fertilization. For fusion of walled cells, the cell wall must be degraded at a precise location but maintained in surrounding regions to protect against lysis. In fission yeast cells, the formin Fus1, which nucleates linear actin filaments, is essential for this process. In this paper, we show that this formin organizes a specific actin structure—the actin fusion focus. Structured illumination microscopy and live-cell imaging of Fus1, actin, and type V myosins revealed an aster of actin filaments whose barbed ends are focalized near the plasma membrane. Focalization requires Fus1 and type V myosins and happens asynchronously always in the M cell first. Type V myosins are essential for fusion and concentrate cell wall hydrolases, but not cell wall synthases, at the fusion focus. Thus, the fusion focus focalizes cell wall dissolution within a broader cell wall synthesis zone to shift from cell growth to cell fusion.
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Affiliation(s)
- Omaya Dudin
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Felipe O Bendezú
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Raphael Groux
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Thierry Laroche
- Bioimaging and Optics Core Facility, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Arne Seitz
- Bioimaging and Optics Core Facility, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Sophie G Martin
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
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47
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Arasada R, Pollard TD. A role for F-BAR protein Rga7p during cytokinesis in S. pombe. J Cell Sci 2015; 128:2259-68. [PMID: 25977474 DOI: 10.1242/jcs.162974] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 05/07/2015] [Indexed: 12/22/2022] Open
Abstract
F-BAR proteins are known to participate in cytokinesis, but their mechanisms are not well understood. Here we investigated Rga7p, an Schizosaccharomyces pombe F-BAR protein with a RhoGAP domain. Localization of Rga7p to the cytokinetic cleavage furrow depends on its F-BAR domain, actin filaments, the formins Cdc12p and For3p, and the presence of a contractile ring. Rga7p is not required for the constriction of the contractile ring but does participate in the transport of a β-glucan synthetase (Bgs4p) from the late Golgi compartments to plasma membrane that is adjacent to the contractile ring. Cells without Rga7p moved Bgs4p normally from the poles to the Golgi complex near to the cell center, but Bgs4p then moved slowly from the late Golgi compartments to the cleavage site. The late arrival and lower than normal numbers of Bgs4p result in septal defects late in cytokinesis, and in the lysis of separating cells, similar to that in cells with mutations in the cwg1(+) gene (which encodes Bgs4p).
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Affiliation(s)
- Rajesh Arasada
- Department of Molecular Cellular and Developmental Biology, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA
| | - Thomas D Pollard
- Department of Molecular Cellular and Developmental Biology, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA Department of Molecular Biophysics and Biochemistry, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA Department of Cell Biology, Yale University, PO Box 208103, New Haven, CT 06520-8103, USA
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48
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Ozaki K, Chikashige Y, Hiraoka Y, Matsumoto T. Fission yeast Scp3 potentially maintains microtubule orientation through bundling. PLoS One 2015; 10:e0120109. [PMID: 25767875 PMCID: PMC4359140 DOI: 10.1371/journal.pone.0120109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/19/2015] [Indexed: 11/19/2022] Open
Abstract
Microtubules play important roles in organelle transport, the maintenance of cell polarity and chromosome segregation and generally form bundles during these processes. The fission yeast gene scp3+ was identified as a multicopy suppressor of the cps3-81 mutant, which is hypersensitive to isopropyl N-3-chlorophenylcarbamate (CIPC), a poison that induces abnormal multipolar spindle formation in higher eukaryotes. In this study, we investigated the function of Scp3 along with the effect of CIPC in the fission yeast Schizosaccharomyces pombe. Microscopic observation revealed that treatment with CIPC, cps3-81 mutation and scp3+ gene deletion disturbed the orientation of microtubules in interphase cells. Overexpression of scp3+ suppressed the abnormal orientation of microtubules by promoting bundling. Functional analysis suggested that Scp3 functions independently from Ase1, a protein largely required for the bundling of the mitotic spindle. A strain lacking the ase1+ gene was more sensitive to CIPC, with the drug affecting the integrity of the mitotic spindle, indicating that CIPC has a mitotic target that has a role redundant with Ase1. These results suggested that multiple systems are independently involved to ensure microtubule orientation by bundling in fission yeast.
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Affiliation(s)
- Kanako Ozaki
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, Japan
| | - Yuji Chikashige
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Hyogo, Japan
| | - Yasushi Hiraoka
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Hyogo, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Tomohiro Matsumoto
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, Japan
- Radiation Biology Center, Kyoto University, Kyoto, Kyoto, Japan
- * E-mail:
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49
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Pollard TD. The value of mechanistic biophysical information for systems-level understanding of complex biological processes such as cytokinesis. Biophys J 2014; 107:2499-507. [PMID: 25468329 PMCID: PMC4255220 DOI: 10.1016/j.bpj.2014.10.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/06/2014] [Accepted: 10/08/2014] [Indexed: 12/15/2022] Open
Abstract
This review illustrates the value of quantitative information including concentrations, kinetic constants and equilibrium constants in modeling and simulating complex biological processes. Although much has been learned about some biological systems without these parameter values, they greatly strengthen mechanistic accounts of dynamical systems. The analysis of muscle contraction is a classic example of the value of combining an inventory of the molecules, atomic structures of the molecules, kinetic constants for the reactions, reconstitutions with purified proteins and theoretical modeling to account for the contraction of whole muscles. A similar strategy is now being used to understand the mechanism of cytokinesis using fission yeast as a favorable model system.
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Affiliation(s)
- Thomas D Pollard
- Departments of Molecular Cellular and Developmental Biology, Molecular Biophysics and Biochemistry, and Cell Biology, Yale University, New Haven, Connecticut.
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Arasada R, Pollard TD. Contractile ring stability in S. pombe depends on F-BAR protein Cdc15p and Bgs1p transport from the Golgi complex. Cell Rep 2014; 8:1533-44. [PMID: 25159149 DOI: 10.1016/j.celrep.2014.07.048] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 05/22/2014] [Accepted: 07/25/2014] [Indexed: 11/17/2022] Open
Abstract
Cdc15p is known to contribute to cytokinesis in fission yeast; however, the protein is not required to assemble the contractile ring of actin and myosin, but it helps to anchor the ring to the plasma membrane. Cdc15p has a lipid-binding F-BAR domain, suggesting that it provides a physical link between the plasma membrane and contractile ring proteins. However, we find that a more important function of Cdc15p during cytokinesis is to help deliver a transmembrane enzyme, Bgs1p (also called Cps1p), from the Golgi apparatus to the plasma membrane, where it appears to anchor the contractile ring. Bgs1p synthesizes the cell wall in the cleavage furrow, but its enzyme activity is not required to anchor the contractile ring. We estimate that ∼ 2,000 Bgs1p molecules are required to anchor the ring. Without Bgs1p anchors, contractile rings slide along the plasma membrane, a phenomenon that depends on an unconventional type II myosin called Myp2p.
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Affiliation(s)
- Rajesh Arasada
- Department of Molecular Cellular and Developmental Biology, Yale University, P.O. Box 208103, New Haven, CT 06520-8103 USA
| | - Thomas D Pollard
- Department of Molecular Cellular and Developmental Biology, Yale University, P.O. Box 208103, New Haven, CT 06520-8103 USA; Department of Molecular Biophysics and Biochemistry, Yale University, P.O. Box 208103, New Haven, CT 06520-8103 USA; Department of Cell Biology, Yale University, P.O. Box 208103, New Haven, CT 06520-8103 USA.
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