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Varela Salgado M, Adriaans IE, Touati SA, Ibanes S, Lai-Kee-Him J, Ancelin A, Cipelletti L, Picas L, Piatti S. Phosphorylation of the F-BAR protein Hof1 drives septin ring splitting in budding yeast. Nat Commun 2024; 15:3383. [PMID: 38649354 PMCID: PMC11035697 DOI: 10.1038/s41467-024-47709-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 04/09/2024] [Indexed: 04/25/2024] Open
Abstract
A double septin ring accompanies cytokinesis in yeasts and mammalian cells. In budding yeast, reorganisation of the septin collar at the bud neck into a dynamic double ring is essential for actomyosin ring constriction and cytokinesis. Septin reorganisation requires the Mitotic Exit Network (MEN), a kinase cascade essential for cytokinesis. However, the effectors of MEN in this process are unknown. Here we identify the F-BAR protein Hof1 as a critical target of MEN in septin remodelling. Phospho-mimicking HOF1 mutant alleles overcome the inability of MEN mutants to undergo septin reorganisation by decreasing Hof1 binding to septins and facilitating its translocation to the actomyosin ring. Hof1-mediated septin rearrangement requires its F-BAR domain, suggesting that it may involve a local membrane remodelling that leads to septin reorganisation. In vitro Hof1 can induce the formation of intertwined septin bundles, while a phosphomimetic Hof1 protein has impaired septin-bundling activity. Altogether, our data indicate that Hof1 modulates septin architecture in distinct ways depending on its phosphorylation status.
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Affiliation(s)
- Maritzaida Varela Salgado
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 34293, Montpellier, France
| | - Ingrid E Adriaans
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 34293, Montpellier, France
| | - Sandra A Touati
- Université Paris Cité, CNRS, Institut Jacques Monod, 75013, Paris, France
| | - Sandy Ibanes
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 34293, Montpellier, France
| | - Joséphine Lai-Kee-Him
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 34090, Montpellier, France
| | - Aurélie Ancelin
- CBS (Centre de Biologie Structurale), University of Montpellier, CNRS UMR 5048, INSERM U 1054, 34090, Montpellier, France
| | - Luca Cipelletti
- L2C (Laboratoire Charles Coulomb), University of Montpellier, CNRS 34095, Montpellier, France
- IUF (Institut Universitaire de France, 75231, Paris, France
| | - Laura Picas
- IRIM (Institut de Recherche en Infectiologie de Montpellier), University of Montpellier, CNRS UMR 9004, 34293, Montpellier, France
| | - Simonetta Piatti
- CRBM (Centre de Recherche en Biologie cellulaire de Montpellier), University of Montpellier, CNRS UMR 5237, 34293, Montpellier, France.
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2
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Wang K, Okada H, Wloka C, Bi E. Unraveling the mechanisms and evolution of a two-domain module in IQGAP proteins for controlling eukaryotic cytokinesis. Cell Rep 2023; 42:113510. [PMID: 38041816 PMCID: PMC10809011 DOI: 10.1016/j.celrep.2023.113510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 08/17/2023] [Accepted: 11/13/2023] [Indexed: 12/04/2023] Open
Abstract
The IQGAP family of proteins plays a crucial role in cytokinesis across diverse organisms, but the underlying mechanisms are not fully understood. In this study, we demonstrate that IQGAPs in budding yeast, fission yeast, and human cells use a two-domain module to regulate their localization as well as the assembly and disassembly of the actomyosin ring during cytokinesis. Strikingly, the calponin homology domains (CHDs) in these IQGAPs bind to distinct cellular F-actin structures with varying specificity, whereas the non-conserved domains immediately downstream of the CHDs in these IQGAPs all target the division site, but differ in timing, localization strength, and binding partners. We also demonstrate that human IQGAP3 acts in parallel to septins and myosin-IIs to mediate the role of anillin in cytokinesis. Collectively, our findings highlight the two-domain mechanism by which IQGAPs regulate cytokinesis in distantly related organisms as well as their evolutionary conservation and divergence.
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Affiliation(s)
- Kangji Wang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - 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; Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, A Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA.
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3
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Stephan OOH. Effects of environmental stress factors on the actin cytoskeleton of fungi and plants: Ionizing radiation and ROS. Cytoskeleton (Hoboken) 2023; 80:330-355. [PMID: 37066976 DOI: 10.1002/cm.21758] [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: 01/16/2023] [Revised: 03/20/2023] [Accepted: 03/29/2023] [Indexed: 04/18/2023]
Abstract
Actin is an abundant and multifaceted protein in eukaryotic cells that has been detected in the cytoplasm as well as in the nucleus. In cooperation with numerous interacting accessory-proteins, monomeric actin (G-actin) polymerizes into microfilaments (F-actin) which constitute ubiquitous subcellular higher order structures. Considering the extensive spatial dimensions and multifunctionality of actin superarrays, the present study analyses the issue if and to what extent environmental stress factors, specifically ionizing radiation (IR) and reactive oxygen species (ROS), affect the cellular actin-entity. In that context, this review particularly surveys IR-response of fungi and plants. It examines in detail which actin-related cellular constituents and molecular pathways are influenced by IR and related ROS. This comprehensive survey concludes that the general integrity of the total cellular actin cytoskeleton is a requirement for IR-tolerance. Actin's functions in genome organization and nuclear events like chromatin remodeling, DNA-repair, and transcription play a key role. Beyond that, it is highly significant that the macromolecular cytoplasmic and cortical actin-frameworks are affected by IR as well. In response to IR, actin-filament bundling proteins (fimbrins) are required to stabilize cables or patches. In addition, the actin-associated factors mediating cellular polarity are essential for IR-survivability. Moreover, it is concluded that a cellular homeostasis system comprising ROS, ROS-scavengers, NADPH-oxidases, and the actin cytoskeleton plays an essential role here. Consequently, besides the actin-fraction which controls crucial genome-integrity, also the portion which facilitates orderly cellular transport and polarized growth has to be maintained in order to survive IR.
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Affiliation(s)
- Octavian O H Stephan
- Department of Biology, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Bavaria, 91058, Germany
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4
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Moyano-Rodríguez Y, Vaquero D, Vilalta-Castany O, Foltman M, Sanchez-Diaz A, Queralt E. PP2A-Cdc55 phosphatase regulates actomyosin ring contraction and septum formation during cytokinesis. Cell Mol Life Sci 2022; 79:165. [PMID: 35230542 PMCID: PMC8888506 DOI: 10.1007/s00018-022-04209-1] [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: 09/01/2021] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 11/03/2022]
Abstract
Eukaryotic cells divide and separate all their components after chromosome segregation by a process called cytokinesis to complete cell division. Cytokinesis is highly regulated by the recruitment of the components to the division site and through post-translational modifications such as phosphorylations. The budding yeast mitotic kinases Cdc28-Clb2, Cdc5, and Dbf2-Mob1 phosphorylate several cytokinetic proteins contributing to the regulation of cytokinesis. The PP2A-Cdc55 phosphatase regulates mitosis counteracting Cdk1- and Cdc5-dependent phosphorylation. This prompted us to propose that PP2A-Cdc55 could also be counteracting the mitotic kinases during cytokinesis. Here we show that in the absence of Cdc55, AMR contraction and the primary septum formation occur asymmetrically to one side of the bud neck supporting a role for PP2A-Cdc55 in cytokinesis regulation. In addition, by in vivo and in vitro assays, we show that PP2A-Cdc55 dephosphorylates the chitin synthase II (Chs2 in budding yeast) a component of the Ingression Progression Complexes (IPCs) involved in cytokinesis. Interestingly, the non-phosphorylable version of Chs2 rescues the asymmetric AMR contraction and the defective septa formation observed in cdc55∆ mutant cells. Therefore, timely dephosphorylation of the Chs2 by PP2A-Cdc55 is crucial for proper actomyosin ring contraction. These findings reveal a new mechanism of cytokinesis regulation by the PP2A-Cdc55 phosphatase and extend our knowledge of the involvement of multiple phosphatases during cytokinesis.
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Affiliation(s)
- Yolanda Moyano-Rodríguez
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - David Vaquero
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain.,Instituto de Biomedicina de Valencia (IBV-CSIC), C/ Jaume Roig 11, Valencia, Spain
| | - Odena Vilalta-Castany
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Magdalena Foltman
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.,Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Alberto Sanchez-Diaz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain.,Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Ethel Queralt
- Cell Cycle Group, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Av. Gran Via de L'Hospitalet 199-203, L'Hospitalet de Llobregat, Barcelona, Spain. .,Instituto de Biomedicina de Valencia (IBV-CSIC), C/ Jaume Roig 11, Valencia, Spain.
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5
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Zheng C, Zhang W, Zhang S, Yang G, Tan L, Guo M. Class I myosin mediated endocytosis and polarization growth is essential for pathogenicity of Magnaporthe oryzae. Appl Microbiol Biotechnol 2021; 105:7395-7410. [PMID: 34536105 DOI: 10.1007/s00253-021-11573-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 10/20/2022]
Abstract
In eukaryotes, myosin provides the necessary impetus for a series of physiological processes, including organelle movement, cytoplasmic flow, cell division, and mitosis. Previously, three members of myosin were identified in Magnaporthe oryzae, with class II and class V myosins playing important roles in intracellular transport, fungal growth, and pathogenicity. However, limited is known about the biological function of the class I myosin protein in the rice blast fungus. Here, we found that Momyo1 is highly expressed during conidiation and infection. Functional characterization of this gene via RNA interference (RNAi) revealed that Momyo1 is required for vegetative growth, conidiation, melanin pigmentation, and pathogenicity of M. oryzae. The Momyo1 knockdown mutant is defective in formation of appressorium-like structures (ALS) at the hyphal tips. In addition, Momyo1 also displays defects on cell wall integrity, hyphal hydrophobicity, extracellular enzyme activities, endocytosis, and formation of the Spitzenkörper. Furthermore, Momyo1 was identified to physically interact with the MoShe4, a She4p/Dim1p orthologue potentially involved in endocytosis, polarization of the actin cytoskeleton. Overall, our findings provide a novel insight into the regulatory mechanism of Momyo1 that is involved in fungal growth, cell wall integrity, endocytosis, and virulence of M. oryzae. KEY POINTS: • Momyo1 is required for vegetative growth and pigmentation of M. oryzae. • Momyo1 is essential for cell wall integrity and endocytosis of M. oryzae. • Momyo1 is involved in hyphal surface hydrophobicity of M. oryzae.
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Affiliation(s)
- Chengcheng Zheng
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
| | - Weiwei Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
| | - Shulin Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
| | - Guogen Yang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
| | - Leyong Tan
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China
| | - Min Guo
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China.
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, 130 West of Changjiang Road, Hefei, 230036, China.
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6
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Prabhakar A, González B, Dionne H, Basu S, Cullen PJ. Spatiotemporal control of pathway sensors and cross-pathway feedback regulate a differentiation MAPK pathway in yeast. J Cell Sci 2021; 134:jcs258341. [PMID: 34347092 PMCID: PMC8353523 DOI: 10.1242/jcs.258341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 06/21/2021] [Indexed: 12/22/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways control cell differentiation and the response to stress. In Saccharomyces cerevisiae, the MAPK pathway that controls filamentous growth (fMAPK) shares components with the pathway that regulates the response to osmotic stress (HOG). Here, we show that the two pathways exhibit different patterns of activity throughout the cell cycle. The different patterns resulted from different expression profiles of genes encoding mucin sensors that regulate the pathways. Cross-pathway regulation from the fMAPK pathway stimulated the HOG pathway, presumably to modulate fMAPK pathway activity. We also show that the shared tetraspan protein Sho1p, which has a dynamic localization pattern throughout the cell cycle, induced the fMAPK pathway at the mother-bud neck. A Sho1p-interacting protein, Hof1p, which also localizes to the mother-bud neck and regulates cytokinesis, also regulated the fMAPK pathway. Therefore, spatial and temporal regulation of pathway sensors, and cross-pathway regulation, control a MAPK pathway that regulates cell differentiation in yeast.
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Affiliation(s)
| | | | | | | | - Paul J. Cullen
- Department of Biological Sciences, University at Buffalo, Buffalo, NY 14260-1300, USA
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7
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Zhang L, Smertenko T, Fahy D, Koteyeva N, Moroz N, Kuchařová A, Novák D, Manoilov E, Smertenko P, Galva C, Šamaj J, Kostyukova AS, Sedbrook JC, Smertenko A. Analysis of formin functions during cytokinesis using specific inhibitor SMIFH2. PLANT PHYSIOLOGY 2021; 186:945-963. [PMID: 33620500 PMCID: PMC8195507 DOI: 10.1093/plphys/kiab085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/03/2021] [Indexed: 05/10/2023]
Abstract
The phragmoplast separates daughter cells during cytokinesis by constructing the cell plate, which depends on interaction between cytoskeleton and membrane compartments. Proteins responsible for these interactions remain unknown, but formins can link cytoskeleton with membranes and several members of formin protein family localize to the cell plate. Progress in functional characterization of formins in cytokinesis is hindered by functional redundancies within the large formin gene family. We addressed this limitation by employing Small Molecular Inhibitor of Formin Homology 2 (SMIFH2), a small-molecule inhibitor of formins. Treatment of tobacco (Nicotiana tabacum) tissue culture cells with SMIFH2 perturbed localization of actin at the cell plate; slowed down both microtubule polymerization and phragmoplast expansion; diminished association of dynamin-related proteins with the cell plate independently of actin and microtubules; and caused cell plate swelling. Another impact of SMIFH2 was shortening of the END BINDING1b (EB1b) and EB1c comets on the growing microtubule plus ends in N. tabacum tissue culture cells and Arabidopsis thaliana cotyledon epidermis cells. The shape of the EB1 comets in the SMIFH2-treated cells resembled that of the knockdown mutant of plant Xenopus Microtubule-Associated protein of 215 kDa (XMAP215) homolog MICROTUBULE ORGANIZATION 1/GEMINI 1 (MOR1/GEM1). This outcome suggests that formins promote elongation of tubulin flares on the growing plus ends. Formins AtFH1 (A. thaliana Formin Homology 1) and AtFH8 can also interact with EB1. Besides cytokinesis, formins function in the mitotic spindle assembly and metaphase to anaphase transition. Our data suggest that during cytokinesis formins function in: (1) promoting microtubule polymerization; (2) nucleating F-actin at the cell plate; (3) retaining dynamin-related proteins at the cell plate; and (4) remodeling of the cell plate membrane.
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Affiliation(s)
- Laining Zhang
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA
| | - Tetyana Smertenko
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA
| | - Deirdre Fahy
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA
| | - Nuria Koteyeva
- Laboratory of Anatomy and Morphology, Komarov Botanical Institute of Russian Academy of Sciences, St. Petersburg 197376, Russia
| | - Natalia Moroz
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, USA
| | - Anna Kuchařová
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, 783 71 Olomouc, Czech Republic
| | - Dominik Novák
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, 783 71 Olomouc, Czech Republic
| | - Eduard Manoilov
- V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, Kyiv, Ukraine
| | - Petro Smertenko
- V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, Kyiv, Ukraine
| | - Charitha Galva
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Jozef Šamaj
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University, 783 71 Olomouc, Czech Republic
| | - Alla S. Kostyukova
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, USA
| | - John C. Sedbrook
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Andrei Smertenko
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA
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8
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Abstract
Septins are an integral component of the cytoskeleton, assembling into higher-order oligomers and filamentous polymers that associate with actin filaments, microtubules and membranes. Here, we review septin interactions with actin and microtubules, and septin-mediated regulation of the organization and dynamics of these cytoskeletal networks, which is critical for cellular morphogenesis. We discuss how actomyosin-associated septins function in cytokinesis, cell migration and host defense against pathogens. We highlight newly emerged roles of septins at the interface of microtubules and membranes with molecular motors, which point to a 'septin code' for the regulation of membrane traffic. Additionally, we revisit the functions of microtubule-associated septins in mitosis and meiosis. In sum, septins comprise a unique module of cytoskeletal regulators that are spatially and functionally specialized and have properties of bona fide actin-binding and microtubule-associated proteins. With many questions still outstanding, the study of septins will continue to provide new insights into fundamental problems of cytoskeletal organization and function.
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9
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Rands TJ, Goode BL. Bil2 Is a Novel Inhibitor of the Yeast Formin Bnr1 Required for Proper Actin Cable Organization and Polarized Secretion. Front Cell Dev Biol 2021; 9:634587. [PMID: 33634134 PMCID: PMC7900418 DOI: 10.3389/fcell.2021.634587] [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: 11/28/2020] [Accepted: 01/20/2021] [Indexed: 11/21/2022] Open
Abstract
Cell growth in budding yeast depends on rapid and on-going assembly and turnover of polarized actin cables, which direct intracellular transport of post-Golgi vesicles to the bud tip. Saccharomyces cerevisiae actin cables are polymerized by two formins, Bni1 and Bnr1. Bni1 assembles cables in the bud, while Bnr1 is anchored to the bud neck and assembles cables that specifically extend filling the mother cell. Here, we report a formin regulatory role for YGL015c, a previously uncharacterized open reading frame, which we have named Bud6 Interacting Ligand 2 (BIL2). bil2Δ cells display defects in actin cable architecture and partially-impaired secretory vesicle transport. Bil2 inhibits Bnr1-mediated actin filament nucleation in vitro, yet has no effect on the rate of Bnr1-mediated filament elongation. This activity profile for Bil2 resembles that of another yeast formin regulator, the F-BAR protein Hof1, and we find that bil2Δ with hof1Δ are synthetic lethal. Unlike Hof1, which localizes exclusively to the bud neck, GFP-Bil2 localizes to the cytosol, secretory vesicles, and sites of polarized cell growth. Further, we provide evidence that Hof1 and Bil2 inhibitory effects on Bnr1 are overcome by distinct mechanisms. Together, our results suggest that Bil2 and Hof1 perform distinct yet genetically complementary roles in inhibiting the actin nucleation activity of Bnr1 to control actin cable assembly and polarized secretion.
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Affiliation(s)
- Thomas J Rands
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA, United States
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA, United States
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10
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Okada H, MacTaggart B, Ohya Y, Bi E. The kinetic landscape and interplay of protein networks in cytokinesis. iScience 2021; 24:101917. [PMID: 33392480 PMCID: PMC7773586 DOI: 10.1016/j.isci.2020.101917] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/08/2022] Open
Abstract
Cytokinesis is executed by protein networks organized into functional modules. Individual proteins within each module have been characterized to various degrees. However, the collective behavior and interplay of the modules remain poorly understood. In this study, we conducted quantitative time-lapse imaging to analyze the accumulation kinetics of more than 20 proteins from different modules of cytokinesis in budding yeast. This analysis has led to a comprehensive picture of the kinetic landscape of cytokinesis, from actomyosin ring (AMR) assembly to cell separation. It revealed that the AMR undergoes biphasic constriction and that the switch between the constriction phases is likely triggered by AMR maturation and primary septum formation. This analysis also provided further insights into the functions of actin filaments and the transglutaminase-like protein Cyk3 in cytokinesis and, in addition, defined Kre6 as the likely enzyme that catalyzes β-1,6-glucan synthesis to drive cell wall maturation during cell growth and division. Cytokinesis is executed by protein modules each with a unique kinetic signature Actomyosin ring constricts in a biphasic manner that is elaborately regulated The transglutaminase-like domain in Cyk3 plays a dual role in cytokinesis Kre6 catalyzes β-1,6-glucan synthesis at the cell surface during growth and division
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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
| | - Brittany MacTaggart
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Yoshikazu Ohya
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
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11
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Xie Y, Miao Y. Polarisome assembly mediates actin remodeling during polarized yeast and fungal growth. J Cell Sci 2021; 134:134/1/jcs247916. [PMID: 33419950 DOI: 10.1242/jcs.247916] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dynamic assembly and remodeling of actin is critical for many cellular processes during development and stress adaptation. In filamentous fungi and budding yeast, actin cables align in a polarized manner along the mother-to-daughter cell axis, and are essential for the establishment and maintenance of polarity; moreover, they rapidly remodel in response to environmental cues to achieve an optimal system response. A formin at the tip region within a macromolecular complex, called the polarisome, is responsible for driving actin cable polymerization during polarity establishment. This polarisome undergoes dynamic assembly through spatial and temporally regulated interactions between its components. Understanding this process is important to comprehend the tuneable activities of the formin-centered nucleation core, which are regulated through divergent molecular interactions and assembly modes within the polarisome. In this Review, we focus on how intrinsically disordered regions (IDRs) orchestrate the condensation of the polarisome components and the dynamic assembly of the complex. In addition, we address how these components are dynamically distributed in and out of the assembly zone, thereby regulating polarized growth. We also discuss the potential mechanical feedback mechanisms by which the force-induced actin polymerization at the tip of the budding yeast regulates the assembly and function of the polarisome.
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Affiliation(s)
- Ying Xie
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
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12
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Wang K, Okada H, Bi E. Comparative Analysis of the Roles of Non-muscle Myosin-IIs in Cytokinesis in Budding Yeast, Fission Yeast, and Mammalian Cells. Front Cell Dev Biol 2020; 8:593400. [PMID: 33330476 PMCID: PMC7710916 DOI: 10.3389/fcell.2020.593400] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/30/2020] [Indexed: 12/31/2022] Open
Abstract
The contractile ring, which plays critical roles in cytokinesis in fungal and animal cells, has fascinated biologists for decades. However, the basic question of how the non-muscle myosin-II and actin filaments are assembled into a ring structure to drive cytokinesis remains poorly understood. It is even more mysterious why and how the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe, and humans construct the ring structure with one, two, and three myosin-II isoforms, respectively. Here, we provide a comparative analysis of the roles of the non-muscle myosin-IIs in cytokinesis in these three model systems, with the goal of defining the common and unique features and highlighting the major questions regarding this family of proteins.
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Affiliation(s)
- Kangji Wang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Hiroki Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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13
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Garabedian MV, Wirshing A, Vakhrusheva A, Turegun B, Sokolova OS, Goode BL. A septin-Hof1 scaffold at the yeast bud neck binds and organizes actin cables. Mol Biol Cell 2020; 31:1988-2001. [PMID: 32579428 PMCID: PMC7543067 DOI: 10.1091/mbc.e19-12-0693] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cellular actin arrays are often highly organized, with characteristic patterns critical to their in vivo functions, yet the mechanisms for establishing these higher order geometries remain poorly understood. In Saccharomyces cerevisiae, formin-polymerized actin cables are spatially organized and aligned along the mother–bud axis to facilitate polarized vesicle traffic. Here, we show that the bud neck–associated F-BAR protein Hof1, independent of its functions in regulating the formin Bnr1, binds to actin filaments and organizes actin cables in vivo. Hof1 bundles actin filaments and links them to septins in vitro. F-actin binding is mediated by the “linker” domain of Hof1, and its deletion leads to cable organization defects in vivo. Using superresolution imaging, we show that Hof1 and septins are patterned at the bud neck into evenly spaced axial pillars (∼200 nm apart), from which actin cables emerge and grow into the mother cell. These results suggest that Hof1, while bound to septins at the bud neck, not only regulates Bnr1 activity, but also binds to actin cables and aligns them along the mother–bud axis. More broadly, these findings provide a strong example of how an actin regulatory protein can be spatially patterned at the cell cortex to govern actin network geometry.
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Affiliation(s)
- Mikael V Garabedian
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA, 02454
| | - Alison Wirshing
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA, 02454
| | - Anna Vakhrusheva
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Bengi Turegun
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA, 02454
| | - Olga S Sokolova
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA, 02454
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14
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Marquardt J, Yao LL, Okada H, Svitkina T, Bi E. The LKB1-like Kinase Elm1 Controls Septin Hourglass Assembly and Stability by Regulating Filament Pairing. Curr Biol 2020; 30:2386-2394.e4. [PMID: 32386534 PMCID: PMC7314651 DOI: 10.1016/j.cub.2020.04.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/20/2020] [Accepted: 04/16/2020] [Indexed: 01/22/2023]
Abstract
Septins form rod-shaped hetero-oligomeric complexes that assemble into filaments and other higher-order structures, such as rings or hourglasses, at the cell division site in fungal and animal cells [1-4] to carry out a wide range of functions, including cytokinesis and cell morphogenesis. However, the architecture of septin higher-order assemblies and their control mechanisms, including regulation by conserved kinases [5, 6], remain largely unknown. In the budding yeast Saccharomyces cerevisiae, the five mitotic septins (Cdc3, Cdc10, Cdc11, Cdc12, and Shs1) localize to the bud neck and form an hourglass before cytokinesis that acts as a scaffold for proteins involved in multiple processes as well as a membrane-diffusible barrier between the mother and developing bud [7-9]. The hourglass is remodeled into a double ring that sandwiches the actomyosin ring at the onset of cytokinesis [10-13]. How septins are assembled into a highly ordered hourglass structure at the division site [13] is largely unexplored. Here we show that the LKB1-like kinase Elm1, which has been implicated in septin organization [14], cell morphogenesis [15], and mitotic exit [16, 17], specifically associates with the septin hourglass during the cell cycle and controls hourglass assembly and stability, especially for the daughter half, by regulating filament pairing and the functionality of its substrate, the septin-binding protein Bni5. This study illustrates how a protein kinase regulates septin architecture at the filament level and suggests that filament pairing is a highly regulated process during septin assembly and remodeling in vivo.
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Affiliation(s)
- Joseph Marquardt
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Lin-Lin Yao
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA; Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hiroki Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Tatyana Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, 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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15
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Chen X, Wang K, Svitkina T, Bi E. Critical Roles of a RhoGEF-Anillin Module in Septin Architectural Remodeling during Cytokinesis. Curr Biol 2020; 30:1477-1490.e3. [PMID: 32197082 DOI: 10.1016/j.cub.2020.02.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/23/2019] [Accepted: 02/10/2020] [Indexed: 12/24/2022]
Abstract
How septin architecture is remodeled from an hourglass to a double ring during cytokinesis in fungal and animal cells remains unknown. Here, we show that during the hourglass-to-double-ring transition in budding yeast, septins acquire a "zonal architecture" in which paired septin filaments that are organized along the mother-bud axis associate with circumferential single septin filaments, the Rho guanine-nucleotide-exchange factor (RhoGEF) Bud3, and the anillin-like protein Bud4 exclusively at the outer zones and with myosin-II filaments in the middle zone. Deletion of Bud3 or its Bud4-interacting domain, but not its RhoGEF domain, leads to a complete loss of the single filaments, whereas deletion of Bud4 or its Bud3-interacting domain destabilizes the transitional hourglass, especially at the mother side, with partial loss of both filament types. Deletion of Bud3 and Bud4 together further weakens the transitional structure and abolishes the double ring formation while causing no obvious defect in actomyosin ring constriction. This and further analyses suggest that Bud3 stabilizes the single filaments, whereas Bud4 strengthens the interaction between the paired and single filaments at the outer zones of the transitional hourglass, as well as in the double ring. This study reveals a striking zonal architecture for the transitional hourglass that pre-patterns two cytokinetic structures-a septin double ring and an actomyosin ring-and also defines the essential roles of a RhoGEF-anillin module in septin architectural remodeling during cytokinesis at the filament level.
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Affiliation(s)
- Xi Chen
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Kangji Wang
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Tatyana Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, 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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Yeast as a Model to Understand Actin-Mediated Cellular Functions in Mammals-Illustrated with Four Actin Cytoskeleton Proteins. Cells 2020; 9:cells9030672. [PMID: 32164332 PMCID: PMC7140605 DOI: 10.3390/cells9030672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/05/2020] [Accepted: 03/05/2020] [Indexed: 12/31/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae has an actin cytoskeleton that comprises a set of protein components analogous to those found in the actin cytoskeletons of higher eukaryotes. Furthermore, the actin cytoskeletons of S. cerevisiae and of higher eukaryotes have some similar physiological roles. The genetic tractability of budding yeast and the availability of a stable haploid cell type facilitates the application of molecular genetic approaches to assign functions to the various actin cytoskeleton components. This has provided information that is in general complementary to that provided by studies of the equivalent proteins of higher eukaryotes and hence has enabled a more complete view of the role of these proteins. Several human functional homologues of yeast actin effectors are implicated in diseases. A better understanding of the molecular mechanisms underpinning the functions of these proteins is critical to develop improved therapeutic strategies. In this article we chose as examples four evolutionarily conserved proteins that associate with the actin cytoskeleton: (1) yeast Hof1p/mammalian PSTPIP1, (2) yeast Rvs167p/mammalian BIN1, (3) yeast eEF1A/eEF1A1 and eEF1A2 and (4) yeast Yih1p/mammalian IMPACT. We compare the knowledge on the functions of these actin cytoskeleton-associated proteins that has arisen from studies of their homologues in yeast with information that has been obtained from in vivo studies using live animals or in vitro studies using cultured animal cell lines.
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17
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Feng J, Islam A, Bean B, Feng J, Sparapani S, Shrivastava M, Goyal A, Omran RP, Mallick J, Whiteway M. Hof1 plays a checkpoint-related role in MMS-induced DNA damage response in Candida albicans. Mol Biol Cell 2020; 31:348-359. [PMID: 31940254 PMCID: PMC7183792 DOI: 10.1091/mbc.e19-06-0316] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Cells depend on robust DNA damage recognition and repair systems to maintain genomic integrity for survival in a mutagenic environment. In the pathogenic yeast Candida albicans, a subset of genes involved in the response to DNA damage-induced genome instability and morphological changes has been found to regulate virulence. To better understand the virulence-linked DNA repair network, we screened for methyl methane sulfonate (MMS) sensitivity within the GRACE conditional expression collection and identified 56 hits. One of these potential DNA damage repair-associated genes, a HOF1 conditional mutant, unexpectedly had a previously characterized function in cytokinesis. Deletion of HOF1 resulted in MMS sensitivity and genome instability, suggesting Hof1 acts in the DNA damage response. By probing genetic interactions with distinct DNA repair pathways, we found that Hof1 is genetically linked to the Rad53 pathway. Furthermore, Hof1 is down-regulated in a Rad53-dependent manner and its importance in the MMS response is reduced when Rad53 is overexpressed or when RAD4 or RAD23 is deleted. Together, this work expands our understanding of the C. albicans DNA repair network and uncovers interplay between the cytokinesis regulator Hof1 and the Rad53-mediated checkpoint.
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Affiliation(s)
- Jinrong Feng
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong, Jiangsu 226001, China
| | - Amjad Islam
- Biology Department, Concordia University, Montreal, QC H4B 1R6, Canada.,Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14642
| | - Bjorn Bean
- Biology Department, Concordia University, Montreal, QC H4B 1R6, Canada
| | - Jia Feng
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong, Jiangsu 226001, China
| | | | | | - Aashima Goyal
- Biology Department, Concordia University, Montreal, QC H4B 1R6, Canada
| | | | - Jaideep Mallick
- Biology Department, Concordia University, Montreal, QC H4B 1R6, Canada
| | - Malcolm Whiteway
- Biology Department, Concordia University, Montreal, QC H4B 1R6, Canada
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18
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Ge SQ, Wu YL, Zhu JL, Tian Y, Wang SS, Gao ZQ. Preliminary investigation of the effects of an FCF inhibitor interference with Septin in the early stage embryos in mice. Mol Med Rep 2019; 19:4401-4406. [PMID: 30896847 DOI: 10.3892/mmr.2019.10072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 09/06/2018] [Indexed: 11/05/2022] Open
Abstract
The objective of the present study was to investigate the effects of for chlorfenuron (FCF) interference with the septin protein on early stage embryos in mice. The 1‑cell embryos were collected and divided into an FCF interference group and a control group. The FCF interference group was cultured in FCF media and the control group was cultured in dimethyl sulphoxide media at 37˚C with 5% CO2 until the desired phase was achieved. Septin2 protein expression was detected using immunofluorescence and western blot analysis. Blastocyst α‑tubulin was stained by immunofluorescence to observe the alterations in spindles and microtubules. The rate of early embryo development into blastocysts was significantly reduced following FCF treatment (P<0.05). In the control group, septin2 was observed with a confocal microscope; septin2 was expressed in embryos at all stages and mainly in the blastomeres from the 2‑cell stage onwards, with the expression concentrated in the nuclei of the blastomeres as identified by strong fluorescence. In the FCF interference group, septin2 was weakly expressed in the nuclei of blastomeres at the 2‑ and 4‑cell stages, and in the granulated blastomeres at the 4‑ and 8‑cell stages. Expression was barely observed in and following the morula. Granulation was observed starting from the 4‑ and 8‑cell stages. Compared with the control group, the FCF interference group exhibited irregular microtubules, abnormal spindle morphology and disordered chromosome arrangement in the blastocysts. The septin2 protein was expressed throughout the early stage embryo from the 2‑cell stage to the blastocyst and localized in the nuclei of blastomeres. When the septin protein experienced interference by the FCF inhibitor, septin2 protein expression was reduced, which simultaneously resulted in abnormal embryonic development, uneven cytoplasmic division, various sizes and a reduced number of blastomeres, granulation in the blastomeres, disordered blastocyst microtubule distribution, spindle shape alterations and an abnormality of chromosome arrangement.
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Affiliation(s)
- Shao-Qin Ge
- The Institute of Traditional Chinese Medicine of Hebei University Health Science Centre, Baoding, Hebei 071002, P.R. China
| | - Yin-Ling Wu
- The Medical Comprehensive Laboratory Center of Hebei University Health Science Centre, Baoding, Hebei 071002, P.R. China
| | - Jin-Liang Zhu
- The Centre for Reproductive Medicine of Peking University Third Hospital, Beijing 100191, P.R. China
| | - Yuan Tian
- The Medical Comprehensive Laboratory Center of Hebei University Health Science Centre, Baoding, Hebei 071002, P.R. China
| | - Shu-Song Wang
- Key Laboratory of Family Planning and Healthy Birth, National Health and Family Planning Commission Hebei Research Institute for Family Planning, Shijiazhuang, Hebei 050071, P.R. China
| | - Zhang-Quan Gao
- Key Laboratory of Family Planning and Healthy Birth, National Health and Family Planning Commission Hebei Research Institute for Family Planning, Shijiazhuang, Hebei 050071, P.R. China
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19
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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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20
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Randhawa A, Kundu D, Sharma A, Prasad R, Mondal AK. Overexpression of the CORVET complex alleviates the fungicidal effects of fludioxonil on the yeast Saccharomyces cerevisiae expressing hybrid histidine kinase 3. J Biol Chem 2018; 294:461-475. [PMID: 30446623 DOI: 10.1074/jbc.ra118.004736] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/25/2018] [Indexed: 11/06/2022] Open
Abstract
The hybrid histidine kinase 3 (HHK3) is a highly conserved sensor kinase in fungi that regulates the downstream HOG/p38 mitogen-activated protein kinase (MAPK). In addition to its role in osmoadaptation, HHK3 is involved in hyphal morphogenesis, conidiation, virulence, and cellular adaptation to oxidative stress. However, the molecular mechanisms by which it controls these processes remain obscure. Moreover, HHK3 is a molecular target for antifungal agents such as fludioxonil, which thereby interferes with the HOG/p38 pathway, leading to the abnormal accumulation of glycerol and subsequent cell lysis. Here, we used a chemical genomics approach with the yeast Saccharomyces cerevisiae to better understand the fungicidal action of fludioxonil and the role of HHK3 in fungal growth and physiology. Our results indicated that the abnormal accumulation of glycerol is not the primary cause of fludioxonil toxicity. Fludioxonil appears to impair endosomal trafficking in the fungal cells. We found that the components of class C core vacuole/endosome tethering (CORVET) complex are essential for yeast viability in the presence of a subthreshold dose of fludioxonil and that their overexpression alleviates fludioxonil toxicity. We also noted that by impeding secretory vesicle trafficking, fludioxonil inhibits hyphal growth in the opportunistic fungal pathogen Candida albicans Our results suggest that HHK3 regulates fungal hyphal growth by affecting vesicle trafficking. Together, our results reveal an important role of CORVET complex in the fungicidal action of fludioxonil downstream of HHK3.
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Affiliation(s)
- Anmoldeep Randhawa
- From the Council of Scientific and Industrial Research (CSIR)-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Debasree Kundu
- From the Council of Scientific and Industrial Research (CSIR)-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India.,School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India, and
| | - Anupam Sharma
- From the Council of Scientific and Industrial Research (CSIR)-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Rajendra Prasad
- Amity Institute of Integrative Sciences and Health, Amity University, Gurgaon 122413, India
| | - Alok K Mondal
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India, and
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21
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Garabedian MV, Stanishneva-Konovalova T, Lou C, Rands TJ, Pollard LW, Sokolova OS, Goode BL. Integrated control of formin-mediated actin assembly by a stationary inhibitor and a mobile activator. J Cell Biol 2018; 217:3512-3530. [PMID: 30076201 PMCID: PMC6168263 DOI: 10.1083/jcb.201803164] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/20/2018] [Accepted: 07/17/2018] [Indexed: 12/15/2022] Open
Abstract
This study shows that in vivo actin nucleation by the yeast formin Bnr1 is controlled through the coordinated effects of two distinct regulators, a stationary inhibitor (the F-BAR protein Hof1) and a mobile activator (Bud6), establishing a positive feedback loop for precise spatial and temporal control of actin assembly. Formins are essential actin assembly factors whose activities are controlled by a diverse array of binding partners. Until now, most formin ligands have been studied on an individual basis, leaving open the question of how multiple inputs are integrated to regulate formins in vivo. Here, we show that the F-BAR domain of Saccharomyces cerevisiae Hof1 interacts with the FH2 domain of the formin Bnr1 and blocks actin nucleation. Electron microscopy of the Hof1–Bnr1 complex reveals a novel dumbbell-shaped structure, with the tips of the F-BAR holding two FH2 dimers apart. Deletion of Hof1’s F-BAR domain in vivo results in disorganized actin cables and secretory defects. The formin-binding protein Bud6 strongly alleviates Hof1 inhibition in vitro, and bud6Δ suppresses hof1Δ defects in vivo. Whereas Hof1 stably resides at the bud neck, we show that Bud6 is delivered to the neck on secretory vesicles. We propose that Hof1 and Bud6 functions are intertwined as a stationary inhibitor and a mobile activator, respectively.
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Affiliation(s)
- Mikael V Garabedian
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA
| | | | - Chenyu Lou
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA
| | - Thomas J Rands
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA
| | - Luther W Pollard
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA
| | - Olga S Sokolova
- Bioengineering Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Bruce L Goode
- Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA
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22
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Wang M, Nishihama R, Onishi M, Pringle JR. Role of the Hof1-Cyk3 interaction in cleavage-furrow ingression and primary-septum formation during yeast cytokinesis. Mol Biol Cell 2018; 29:597-609. [PMID: 29321253 PMCID: PMC6004579 DOI: 10.1091/mbc.e17-04-0227] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 12/26/2017] [Accepted: 01/03/2018] [Indexed: 11/11/2022] Open
Abstract
In Saccharomyces cerevisiae, it is well established that Hof1, Cyk3, and Inn1 contribute to septum formation and cytokinesis. Because hof1∆ and cyk3∆ single mutants have relatively mild defects but hof1∆ cyk3∆ double mutants are nearly dead, it has been hypothesized that these proteins contribute to parallel pathways. However, there is also evidence that they interact physically. In this study, we examined this interaction and its functional significance in detail. Our data indicate that the interaction 1) is mediated by a direct binding of the Hof1 SH3 domain to a proline-rich motif in Cyk3; 2) occurs specifically at the time of cytokinesis but is independent of the (hyper)phosphorylation of both proteins that occurs at about the same time; 3) is dispensable for the normal localization of both proteins; 4) is essential for normal primary-septum formation and a normal rate of cleavage-furrow ingression; and 5) becomes critical for growth when either Inn1 or the type II myosin Myo1 (a key component of the contractile actomyosin ring) is absent. The similarity in phenotype between cyk3∆ mutants and mutants specifically lacking the Hof1-Cyk3 interaction suggests that the interaction is particularly important for Cyk3 function, but it may be important for Hof1 function as well.
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Affiliation(s)
- Meng Wang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Ryuichi Nishihama
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Masayuki Onishi
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - John R Pringle
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
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23
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Abstract
SUMMARYCell division-cytokinesis-involves large-scale rearrangements of the entire cell. Primarily driven by cytoskeletal proteins, cytokinesis also depends on topological rearrangements of the plasma membrane, which are coordinated with nuclear division in both space and time. Despite the fundamental nature of the process, different types of eukaryotic cells show variations in both the structural mechanisms of cytokinesis and the regulatory controls. In animal cells and fungi, a contractile actomyosin-based structure plays a central, albeit flexible, role. Here, the underlying molecular mechanisms are summarized and integrated and common themes are highlighted.
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Affiliation(s)
- Michael Glotzer
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637
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24
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Oh Y, Schreiter JH, Okada H, Wloka C, Okada S, Yan D, Duan X, Bi E. Hof1 and Chs4 Interact via F-BAR Domain and Sel1-like Repeats to Control Extracellular Matrix Deposition during Cytokinesis. Curr Biol 2017; 27:2878-2886.e5. [PMID: 28918945 PMCID: PMC5658023 DOI: 10.1016/j.cub.2017.08.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/07/2017] [Accepted: 08/15/2017] [Indexed: 11/24/2022]
Abstract
Localized extracellular matrix (ECM) remodeling is thought to stabilize the cleavage furrow and maintain cell shape during cytokinesis [1-14]. This remodeling is spatiotemporally coordinated with a cytoskeletal structure pertaining to a kingdom of life, for example the FtsZ ring in bacteria [15], the phragmoplast in plants [16], and the actomyosin ring in fungi and animals [17, 18]. Although the cytoskeletal structures have been analyzed extensively, the mechanisms of ECM remodeling remain poorly understood. In the budding yeast Saccharomyces cerevisiae, ECM remodeling refers to sequential formations of the primary and secondary septa that are catalyzed by chitin synthase-II (Chs2) and chitin synthase-III (the catalytic subunit Chs3 and its activator Chs4), respectively [18, 19]. Surprisingly, both Chs2 and Chs3 are delivered to the division site at the onset of cytokinesis [6, 20]. What keeps Chs3 inactive until secondary septum formation remains unknown. Here, we show that Hof1 binds to the Sel1-like repeats (SLRs) of Chs4 via its F-BAR domain and inhibits Chs3-mediated chitin synthesis during cytokinesis. In addition, Hof1 is required for rapid accumulation as well as efficient removal of Chs4 at the division site. This study uncovers a mechanism by which Hof1 controls timely activation of Chs3 during cytokinesis and defines a novel interaction and function for the conserved F-BAR domain and SLR that are otherwise known for their abilities to bind membrane lipids [21, 22] and scaffold protein complex formation [23].
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Affiliation(s)
- Younghoon Oh
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - Jennifer H Schreiter
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA
| | - 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
| | - Satoshi Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA; Department of Medical Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Di Yan
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, USA; Cleveland Clinic Lerner College of Medicine, Cleveland, OH 44195, USA
| | - Xudong Duan
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6058, 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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Guo M, Tan L, Nie X, Zhang Z. A class-II myosin is required for growth, conidiation, cell wall integrity and pathogenicity of Magnaporthe oryzae. Virulence 2017; 8:1335-1354. [PMID: 28448785 DOI: 10.1080/21505594.2017.1323156] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
In eukaryotic organisms, myosin proteins are the major ring components that are involved in cytokinesis. To date, little is known about the biologic functions of myosin proteins in Magnaporthe oryzae. In this study, insertional mutagenesis conducted in M. oryzae led to identification of Momyo2, a pathogenicity gene predicted to encode a class-II myosin protein homologous to Saccharomyces cerevisiae Myo1. According to qRT-PCR, Momyo2 is highly expressed during early infectious stage. When this gene was disrupted, the resultant mutant isolates were attenuated in virulence on rice and barley. These were likely caused by defective mycelial growth and frequent emergence of branch hyphae and septum. The Momyo2 mutants were also defective in conidial and appressorial development, characterized by abnormal conidia and appressoria. These consequently resulted in plant tissue penetration defects that the wild type strain lacked, and mutants being less pathogenic. Cytorrhysis assay, CFW staining of appressorium and monitoring of protoplast release suggested that appressorial wall was altered, presumably affecting the level of turgor pressure within appressorium. Furthermore, impairments in conidial germination, glycogen metabolites, tolerance to exogenous stresses and scavenging of host-derived reactive oxygen species were associated with defects on appressorium mediated penetration, and therefore attenuated the virulence of Momyo2 mutants. Taken together, these results suggest that Momyo2 plays pleiotropic roles in fungal development, and is required for the full pathogenicity of M. oryzae.
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Affiliation(s)
- Min Guo
- a Department of Plant Pathology , College of Plant Protection, Anhui Agricultural University , Hefei , China
| | - Leyong Tan
- a Department of Plant Pathology , College of Plant Protection, Anhui Agricultural University , Hefei , China
| | - Xiang Nie
- a Department of Plant Pathology , College of Plant Protection, Anhui Agricultural University , Hefei , China
| | - Zhengguang Zhang
- b Department of Plant Pathology , College of Plant Protection, Nanjing Agricultural University , Nanjing , China
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Altamirano S, Chandrasekaran S, Kozubowski L. Mechanisms of Cytokinesis in Basidiomycetous Yeasts. FUNGAL BIOL REV 2017; 31:73-87. [PMID: 28943887 DOI: 10.1016/j.fbr.2016.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
While mechanisms of cytokinesis exhibit considerable plasticity, it is difficult to precisely define the level of conservation of this essential part of cell division in fungi, as majority of our knowledge is based on ascomycetous yeasts. However, in the last decade more details have been uncovered regarding cytokinesis in the second largest fungal phylum, basidiomycetes, specifically in two yeasts, Cryptococcus neoformans and Ustilago maydis. Based on these findings, and current sequenced genomes, we summarize cytokinesis in basidiomycetous yeasts, indicating features that may be unique to this phylum, species-specific characteristics, as well as mechanisms that may be common to all eukaryotes.
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Affiliation(s)
- Sophie Altamirano
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | | | - Lukasz Kozubowski
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
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27
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Abstract
In budding yeast cells, cytokinesis is achieved by the successful division of the cytoplasm into two daughter cells, but the precise mechanisms of cell division and its regulation are still rather poorly understood. The Mitotic Exit Network (MEN) is the signaling cascade that is responsible for the release of Cdc14 phosphatase leading to the inactivation of the kinase activity associated to cyclin-dependent kinases (CDK), which drives exit from mitosis and a rapid and efficient cytokinesis. Mitotic CDK impairs the activation of MEN before anaphase, and activation of MEN in anaphase leads to the inactivation of CDK, which presents a challenge to determine the contribution that each pathway makes to the successful onset of cytokinesis. To determine CDK and MEN contribution to cytokinesis irrespectively of each other, here we present methods to induce cytokinesis after the inactivation of CDK activity in temperature sensitive mutants of the MEN pathway. An array of methods to monitor the cellular events associated with the successful cytokinesis is included.
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Affiliation(s)
- Magdalena Foltman
- Instituto de Biomedicina y Biotecnología de Cantabria, Consejo Superior de Investigaciones Científicas, Universidad de Cantabria, c/ Albert Einstein 22, Santander, 39011, Spain
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Cardenal Herrera Oria s/n, Santander, 39011, Spain
| | - Alberto Sanchez-Diaz
- Instituto de Biomedicina y Biotecnología de Cantabria, Consejo Superior de Investigaciones Científicas, Universidad de Cantabria, c/ Albert Einstein 22, Santander, 39011, Spain.
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Cardenal Herrera Oria s/n, Santander, 39011, Spain.
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28
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Abstract
The Mitotic Exit Network (MEN) is an essential signaling pathway, closely related to the Hippo pathway in mammals, which promotes mitotic exit and initiates cytokinesis in the budding yeast Saccharomyces cerevisiae. Here, we summarize the current knowledge about the MEN components and their regulation.
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Affiliation(s)
- Bàrbara Baro
- Department of Pediatrics, Division of Infectious Diseases,Stanford University School of Medicine, Stanford, CA, USA.
| | - Ethel Queralt
- Cancer Epigenetics & Biology Program, Hospitalet de Llobregat, Barcelona, Spain.
| | - Fernando Monje-Casas
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio, s/n. P.C.T. Cartuja 93., 41092, Sevilla, Spain.
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29
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Abstract
Cytokinesis is essential for the survival of all organisms. It requires concerted functions of cell signaling, force production, exocytosis, and extracellular matrix remodeling. Due to the conservation in core components and mechanisms between fungal and animal cells, the budding yeast Saccharomyces cerevisiae has served as an attractive model for studying this fundamental process. In this review, we discuss the mechanics and regulation of distinct events of cytokinesis in budding yeast, including the assembly, constriction, and disassembly of the actomyosin ring, septum formation, abscission, and their spatiotemporal coordination. We also highlight the key concepts and questions that are common to animal and fungal cytokinesis.
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Affiliation(s)
- Yogini P Bhavsar-Jog
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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30
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Perez AM, Finnigan GC, Roelants FM, Thorner J. Septin-Associated Protein Kinases in the Yeast Saccharomyces cerevisiae. Front Cell Dev Biol 2016; 4:119. [PMID: 27847804 PMCID: PMC5088441 DOI: 10.3389/fcell.2016.00119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 10/14/2016] [Indexed: 01/19/2023] Open
Abstract
Septins are a family of eukaryotic GTP-binding proteins that associate into linear rods, which, in turn, polymerize end-on-end into filaments, and further assemble into other, more elaborate super-structures at discrete subcellular locations. Hence, septin-based ensembles are considered elements of the cytoskeleton. One function of these structures that has been well-documented in studies conducted in budding yeast Saccharomyces cerevisiae is to serve as a scaffold that recruits regulatory proteins, which dictate the spatial and temporal control of certain aspects of the cell division cycle. In particular, septin-associated protein kinases couple cell cycle progression with cellular morphogenesis. Thus, septin-containing structures serve as signaling platforms that integrate a multitude of signals and coordinate key downstream networks required for cell cycle passage. This review summarizes what we currently understand about how the action of septin-associated protein kinases and their substrates control information flow to drive the cell cycle into and out of mitosis, to regulate bud growth, and especially to direct timely and efficient execution of cytokinesis and cell abscission. Thus, septin structures represent a regulatory node at the intersection of many signaling pathways. In addition, and importantly, the activities of certain septin-associated protein kinases also regulate the state of organization of the septins themselves, creating a complex feedback loop.
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Affiliation(s)
- Adam M Perez
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley Berkeley, CA, USA
| | - Gregory C Finnigan
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley Berkeley, CA, USA
| | - Françoise M Roelants
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley Berkeley, CA, USA
| | - Jeremy Thorner
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley Berkeley, CA, USA
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31
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Juanes MA, Piatti S. The final cut: cell polarity meets cytokinesis at the bud neck in S. cerevisiae. Cell Mol Life Sci 2016; 73:3115-36. [PMID: 27085703 PMCID: PMC4951512 DOI: 10.1007/s00018-016-2220-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/22/2016] [Accepted: 04/05/2016] [Indexed: 02/07/2023]
Abstract
Cell division is a fundamental but complex process that gives rise to two daughter cells. It includes an ordered set of events, altogether called "the cell cycle", that culminate with cytokinesis, the final stage of mitosis leading to the physical separation of the two daughter cells. Symmetric cell division equally partitions cellular components between the two daughter cells, which are therefore identical to one another and often share the same fate. In many cases, however, cell division is asymmetrical and generates two daughter cells that differ in specific protein inheritance, cell size, or developmental potential. The budding yeast Saccharomyces cerevisiae has proven to be an excellent system to investigate the molecular mechanisms governing asymmetric cell division and cytokinesis. Budding yeast is highly polarized during the cell cycle and divides asymmetrically, producing two cells with distinct sizes and fates. Many components of the machinery establishing cell polarization during budding are relocalized to the division site (i.e., the bud neck) for cytokinesis. In this review we recapitulate how budding yeast cells undergo polarized processes at the bud neck for cell division.
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Affiliation(s)
- Maria Angeles Juanes
- Centre de Recherche en Biologie Cellulaire de Montpellier, 1919 Route de Mende, 34293, Montpellier, France
- Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Simonetta Piatti
- Centre de Recherche en Biologie Cellulaire de Montpellier, 1919 Route de Mende, 34293, Montpellier, France.
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Woods B, Lai H, Wu CF, Zyla TR, Savage NS, Lew DJ. Parallel Actin-Independent Recycling Pathways Polarize Cdc42 in Budding Yeast. Curr Biol 2016; 26:2114-26. [PMID: 27476596 DOI: 10.1016/j.cub.2016.06.047] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 05/03/2016] [Accepted: 06/21/2016] [Indexed: 12/31/2022]
Abstract
The highly conserved Rho-family GTPase Cdc42 is an essential regulator of polarity in many different cell types. During polarity establishment, Cdc42 becomes concentrated at a cortical site, where it interacts with downstream effectors to orient the cytoskeleton along the front-back axis. To concentrate Cdc42, loss of Cdc42 by diffusion must be balanced by recycling to the front. In Saccharomyces cerevisiae, the guanine nucleotide dissociation inhibitor (GDI) Rdi1 recycles Cdc42 through the cytoplasm. Loss of Rdi1 slowed but did not eliminate Cdc42 accumulation at the front, suggesting the existence of other recycling pathways. One proposed pathway involves actin-directed trafficking of vesicles carrying Cdc42 to the front. However, we found no role for F-actin in Cdc42 concentration, even in rdi1Δ cells. Instead, Cdc42 was still able to exchange between the membrane and cytoplasm in rdi1Δ cells, albeit at a reduced rate. Membrane-cytoplasm exchange of GDP-Cdc42 was faster than that of GTP-Cdc42, and computational modeling indicated that such exchange would suffice to promote polarization. We also uncovered a novel role for the Cdc42-directed GTPase-activating protein (GAP) Bem2 in Cdc42 polarization. Bem2 was known to act in series with Rdi1 to promote recycling of Cdc42, but we found that rdi1Δ bem2Δ mutants were synthetically lethal, suggesting that they also act in parallel. We suggest that GAP activity cooperates with the GDI to counteract the dissipative effect of a previously unappreciated pathway whereby GTP-Cdc42 escapes from the polarity site through the cytoplasm.
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Affiliation(s)
- Benjamin Woods
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Helen Lai
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Chi-Fang Wu
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Trevin R Zyla
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Natasha S Savage
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
| | - Daniel J Lew
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
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Control of Formin Distribution and Actin Cable Assembly by the E3 Ubiquitin Ligases Dma1 and Dma2. Genetics 2016; 204:205-20. [PMID: 27449057 DOI: 10.1534/genetics.116.189258] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/18/2016] [Indexed: 11/18/2022] Open
Abstract
Formins are widespread actin-polymerizing proteins that play pivotal roles in a number of processes, such as cell polarity, morphogenesis, cytokinesis, and cell migration. In agreement with their crucial function, formins are prone to a variety of regulatory mechanisms that include autoinhibition, post-translational modifications, and interaction with formin modulators. Furthermore, activation and function of formins is intimately linked to their ability to interact with membranes. In the budding yeast Saccharomyces cerevisiae, the two formins Bni1 and Bnr1 play both separate and overlapping functions in the organization of the actin cytoskeleton. In addition, they are controlled by both common and different regulatory mechanisms. Here we show that proper localization of both formins requires the redundant E3 ubiquitin ligases Dma1 and Dma2, which were previously involved in spindle positioning and septin organization. In dma1 dma2 double mutants, formin distribution at polarity sites is impaired, thus causing defects in the organization of the actin cable network and hypersensitivity to the actin depolymerizer latrunculin B. Expression of a hyperactive variant of Bni1 (Bni1-V360D) rescues these defects and partially restores proper spindle positioning in the mutant, suggesting that the failure of dma1 dma2 mutant cells to position the spindle is partly due to faulty formin activity. Strikingly, Dma1/2 interact physically with both formins, while their ubiquitin-ligase activity is required for formin function and polarized localization. Thus, ubiquitylation of formin or a formin interactor(s) could promote formin binding to membrane and its ability to nucleate actin. Altogether, our data highlight a novel level of formin regulation that further expands our knowledge of the complex and multilayered controls of these key cytoskeleton organizers.
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34
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Abstract
Cytokinesis is essential for development and survival of all organisms by increasing cell number and diversity. It is a highly regulated process that requires spatiotemporal coordination of hundreds of proteins functioning in the assembly, constriction, and disassembly of a contractile actomyosin ring, targeted vesicle fusion, and localized extracellular matrix remodeling. Cytokinesis has been studied in multiple systems with a wide range of technologies to learn the common principles. In this chapter, we describe the analysis of protein dynamics during cytokinesis in the budding yeast Saccharomyces cerevisiae by several live-cell imaging methods. This, in combination with the power of yeast genetics, has yielded novel insights into the mechanism of cytokinesis. Similar approaches are increasingly used to study this fundamental process in more complex systems.
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Affiliation(s)
- S Okada
- University of Pennsylvania, Philadelphia, PA, United States; Kyushu University, Fukuoka, Japan
| | - C Wloka
- University of Pennsylvania, Philadelphia, PA, United States; University of Groningen, Groningen, The Netherlands
| | - E Bi
- University of Pennsylvania, Philadelphia, PA, United States
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35
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Foltman M, Molist I, Arcones I, Sacristan C, Filali-Mouncef Y, Roncero C, Sanchez-Diaz A. Ingression Progression Complexes Control Extracellular Matrix Remodelling during Cytokinesis in Budding Yeast. PLoS Genet 2016; 12:e1005864. [PMID: 26891268 PMCID: PMC4758748 DOI: 10.1371/journal.pgen.1005864] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 01/22/2016] [Indexed: 12/02/2022] Open
Abstract
Eukaryotic cells must coordinate contraction of the actomyosin ring at the division site together with ingression of the plasma membrane and remodelling of the extracellular matrix (ECM) to support cytokinesis, but the underlying mechanisms are still poorly understood. In eukaryotes, glycosyltransferases that synthesise ECM polysaccharides are emerging as key factors during cytokinesis. The budding yeast chitin synthase Chs2 makes the primary septum, a special layer of the ECM, which is an essential process during cell division. Here we isolated a group of actomyosin ring components that form complexes together with Chs2 at the cleavage site at the end of the cell cycle, which we named ‘ingression progression complexes’ (IPCs). In addition to type II myosin, the IQGAP protein Iqg1 and Chs2, IPCs contain the F-BAR protein Hof1, and the cytokinesis regulators Inn1 and Cyk3. We describe the molecular mechanism by which chitin synthase is activated by direct association of the C2 domain of Inn1, and the transglutaminase-like domain of Cyk3, with the catalytic domain of Chs2. We used an experimental system to find a previously unanticipated role for the C-terminus of Inn1 in preventing the untimely activation of Chs2 at the cleavage site until Cyk3 releases the block on Chs2 activity during late mitosis. These findings support a model for the co-ordinated regulation of cell division in budding yeast, in which IPCs play a central role. Cytokinesis is the process by which a cell divides in two and occurs once cells have replicated and segregated their chromosomes. Eukaryotic cells assemble a molecular machine called the actomyosin ring that drives cytokinesis. Contraction of the actomyosin ring is coupled to ingression of the plasma membrane and extracellular matrix remodelling. In eukaryotes, glycosyltransferases that synthesise polysaccharides of the extracellular matrix are emerging as essential factors during cytokinesis. Defects associated with the function of those glycosyltransferases induce the failure of cell division, which promotes the formation of genetically unstable tetraploid cells. Budding yeast cells contain a glycosyltransferase called Chs2 that makes a special layer of extracellular matrix and is essential during cell division. Our findings provide new insights into the molecular mechanism by which the cytokinesis regulators Inn1 and Cyk3 finely regulate the activity of glycosyltransferase Chs2 at the end of mitosis. In addition we isolated a group of actomyosin ring components that form complexes together with Chs2 and Inn1 at the cleavage site, which we have named ‘ingression progression complexes’. These complexes coordinate the contraction of the actomyosin ring, ingression of the plasma membrane and extracellular matrix remodelling in a precise manner. Chs2 is indeed a key factor for coordinating these events. It appears that similar principles could apply to other eukaryotic species, such as fission yeast even if the identity of the relevant glycosyltransferase has changed over the evolution. Taking into account the conservation of the basic cytokinetic mechanisms future studies should try to determine whether a glycosyltransferase similar to Chs2 plays a key role during cytokinesis in human cells.
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Affiliation(s)
- Magdalena Foltman
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Iago Molist
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Irene Arcones
- Instituto de Biología Funcional y Genómica, Departamento de Microbiología y Genética, CSIC, Universidad de Salamanca, Salamanca, Spain
| | - Carlos Sacristan
- Instituto de Biología Funcional y Genómica, Departamento de Microbiología y Genética, CSIC, Universidad de Salamanca, Salamanca, Spain
| | - Yasmina Filali-Mouncef
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
| | - Cesar Roncero
- Instituto de Biología Funcional y Genómica, Departamento de Microbiología y Genética, CSIC, Universidad de Salamanca, Salamanca, Spain
| | - Alberto Sanchez-Diaz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, CSIC, Santander, Spain
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, Santander, Spain
- * E-mail:
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36
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Abstract
Cytokinesis is the final process in the cell cycle that physically divides one cell into two. In budding yeast, cytokinesis is driven by a contractile actomyosin ring (AMR) and the simultaneous formation of a primary septum, which serves as template for cell wall deposition. AMR assembly, constriction, primary septum formation and cell wall deposition are successive processes and tightly coupled to cell cycle progression to ensure the correct distribution of genetic material and cell organelles among the two rising cells prior to cell division. The role of the AMR in cytokinesis and the molecular mechanisms that drive AMR constriction and septation are the focus of current research. This review summarizes the recent progresses in our understanding of how budding yeast cells orchestrate the multitude of molecular mechanisms that control AMR driven cytokinesis in a spatio-temporal manner to achieve an error free cell division.
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Orii M, Kono K, Wen HI, Nakanishi M. PP1-Dependent Formin Bnr1 Dephosphorylation and Delocalization from a Cell Division Site. PLoS One 2016; 11:e0146941. [PMID: 26771880 PMCID: PMC4714816 DOI: 10.1371/journal.pone.0146941] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/23/2015] [Indexed: 02/07/2023] Open
Abstract
Cell cycle ends with cytokinesis that is the physical separation of a cell into two daughter cells. For faithful cytokinesis, cells integrate multiple processes, such as actomyosin ring formation, contraction and plasma membrane closure, into coherent responses. Linear actin assembly by formins is essential for formation and maintenance of actomyosin ring. Although budding yeast’s two formins, Bni1 and Bnr1, are known to switch their subcellular localization at the division site prior to cytokinesis, the underlying mechanisms were not completely understood. Here, we provide evidence showing that Bnr1 is dephosphorylated concomitant with its release from the division site. Impaired PP1/Glc7 activity delayed Bnr1 release and dephosphorylation, Bni1 recruitment and actomyosin ring formation at the division site. These results suggest the involvement of Glc7 in this regulation. Further, we identified Ref2 as the PP1 regulatory subunit responsible for this regulation. Taken together, Glc7 and Ref2 may have a role in actomyosin ring formation by modulating the localization of formins during cytokinesis.
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Affiliation(s)
- Minami Orii
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467–8601, Japan
| | - Keiko Kono
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467–8601, Japan
- * E-mail: (MN); (KK)
| | - Hsin-I Wen
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467–8601, Japan
| | - Makoto Nakanishi
- Department of Cell Biology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467–8601, Japan
- * E-mail: (MN); (KK)
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38
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Moosavi B, Mousavi B, Yang GF. Actin, Membrane Trafficking and the Control of Prion Induction, Propagation and Transmission in Yeast. Traffic 2015; 17:5-20. [PMID: 26503767 DOI: 10.1111/tra.12344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 10/23/2015] [Accepted: 10/23/2015] [Indexed: 12/16/2022]
Abstract
The model eukaryotic yeast Saccharomyces cerevisiae has proven a useful model system in which prion biogenesis and elimination are studied. Several yeast prions exist in budding yeast and a number of studies now suggest that these alternate protein conformations may play important roles in the cell. During the last few years cellular factors affecting prion induction, propagation and elimination have been identified. Amongst these, proteins involved in the regulation of the actin cytoskeleton and dynamic membrane processes such as endocytosis have been found to play a critical role not only in facilitating de novo prion formation but also in prion propagation. Here we briefly review prion formation and maintenance with special attention given to the cellular processes that require the functionality of the actin cytoskeleton.
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Affiliation(s)
- Behrooz Moosavi
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
| | - Bibimaryam Mousavi
- Laboratory of Organometallics, Catalysis and Ordered Materials, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, P.R. China
| | - Guang-Fu Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, P.R. China
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The N-terminal domains determine cellular localization and functions of the Doa4 and Ubp5 deubiquitinating enzymes. Biochem Biophys Res Commun 2015; 467:570-6. [PMID: 26427873 DOI: 10.1016/j.bbrc.2015.09.136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 09/24/2015] [Indexed: 11/24/2022]
Abstract
Ubiquitination is involved in numerous cellular regulatory mechanisms including the cell cycle, signal transduction and quality control. Ubiquitin modifies proteins by consecutive actions of ubiquitin-activating/conjugating enzymes. Attachment of ubiquitin is reversible. Deubiquitinating enzymes are responsible for removal of ubiquitin from ubiquitin-protein conjugates. Genome of the yeast Saccharomyces cerevisiae encodes structurally related but functionally distinct enzymes - Doa4 and Ubp5. Doa4 is involved in general ubiquitin-dependent proteolysis and is responsible for deubiquitination of ubiquitin-protein conjugates at the cytoplasmic face of the late endosome. The N-terminal domain targets the enzyme to the endosome membrane after ESCRT-III complex has formed there. By contrast, corresponding region of homologous Ubp5 is critical for its bud neck localization in dividing cells. Conceivably, Ubp5 plays an essential role in cytokinesis. Here we show that Doa4 physically interacts with the ESCRT-III component Snf7 and preferentially cleaves Lys63-linked ubiquitin oligomers involved in membrane protein trafficking. We also demonstrate that the unstable regulator of cytokinesis Hof1 accumulates in proteasomal mutants and is required for cellular localization of Ubp5.
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40
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Miller DP, Hall H, Chaparian R, Mara M, Mueller A, Hall MC, Shannon KB. Dephosphorylation of Iqg1 by Cdc14 regulates cytokinesis in budding yeast. Mol Biol Cell 2015; 26:2913-26. [PMID: 26085509 PMCID: PMC4571329 DOI: 10.1091/mbc.e14-12-1637] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 01/11/2023] Open
Abstract
Cytokinesis separates cells by contraction of a ring composed of filamentous actin (F-actin) and type II myosin. Iqg1, an IQGAP family member, is an essential protein in Saccharomyces cerevisiae required for assembly and contraction of the actomyosin ring. Localization of F-actin to the ring occurs only after anaphase and is mediated by the calponin homology domain (CHD) of Iqg1, but the regulatory mechanisms that temporally restrict actin ring assembly are not well defined. We tested the hypothesis that dephosphorylation of four perfect cyclin-dependent kinase (Cdk) sites flanking the CHD promotes actin ring formation, using site-specific alanine mutants. Cells expressing the nonphosphorylatable iqg1-4A allele formed actin rings before anaphase and exhibited defects in myosin contraction and cytokinesis. The Cdc14 phosphatase is required for normal cytokinesis and acts on specific Cdk phosphorylation sites. Overexpression of Cdc14 resulted in premature actin ring assembly, whereas inhibition of Cdc14 function prevented actin ring formation. Cdc14 associated with Iqg1, dependent on several CHD-flanking Cdk sites, and efficiently dephosphorylated these sites in vitro. Of importance, the iqg1-4A mutant rescued the inability of cdc14-1 cells to form actin rings. Our data support a model in which dephosphorylation of Cdk sites around the Iqg1 CHD by Cdc14 is both necessary and sufficient to promote actin ring formation. Temporal control of actin ring assembly by Cdk and Cdc14 may help to ensure that cytokinesis onset occurs after nuclear division is complete.
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Affiliation(s)
- Daniel P. Miller
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65401
| | - Hana Hall
- Department of Biochemistry, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
| | - Ryan Chaparian
- Department of Biochemistry, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
| | - Madison Mara
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65401
| | - Alison Mueller
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65401
| | - Mark C. Hall
- Department of Biochemistry, Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
| | - Katie B. Shannon
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO 65401
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Roelants FM, Su BM, von Wulffen J, Ramachandran S, Sartorel E, Trott AE, Thorner J. Protein kinase Gin4 negatively regulates flippase function and controls plasma membrane asymmetry. ACTA ACUST UNITED AC 2015; 208:299-311. [PMID: 25646086 PMCID: PMC4315245 DOI: 10.1083/jcb.201410076] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In yeast, the protein kinase Gin4 locally controls plasma membrane lipid asymmetry, which is necessary for optimal cytokinesis. Plasma membrane function requires distinct leaflet lipid compositions. Two of the P-type ATPases (flippases) in yeast, Dnf1 and Dnf2, translocate aminoglycerophospholipids from the outer to the inner leaflet, stimulated via phosphorylation by cortically localized protein kinase Fpk1. By monitoring Fpk1 activity in vivo, we found that Fpk1 was hyperactive in cells lacking Gin4, a protein kinase previously implicated in septin collar assembly. Gin4 colocalized with Fpk1 at the cortical site of future bud emergence and phosphorylated Fpk1 at multiple sites, which we mapped. As judged by biochemical and phenotypic criteria, a mutant (Fpk111A), in which 11 sites were mutated to Ala, was hyperactive, causing increased inward transport of phosphatidylethanolamine. Thus, Gin4 is a negative regulator of Fpk1 and therefore an indirect negative regulator of flippase function. Moreover, we found that decreasing flippase function rescued the growth deficiency of four different cytokinesis mutants, which suggests that the primary function of Gin4 is highly localized control of membrane lipid asymmetry and is necessary for optimal cytokinesis.
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Affiliation(s)
- Françoise M Roelants
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Brooke M Su
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Joachim von Wulffen
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Subramaniam Ramachandran
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Elodie Sartorel
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Amy E Trott
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Jeremy Thorner
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
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Feng Z, Okada S, Cai G, Zhou B, Bi E. Myosin‑II heavy chain and formin mediate the targeting of myosin essential light chain to the division site before and during cytokinesis. Mol Biol Cell 2015; 26:1211-24. [PMID: 25631819 PMCID: PMC4454170 DOI: 10.1091/mbc.e14-09-1363] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
MLC1 is a haploinsufficient gene encoding the essential light chain for Myo1, the sole myosin‑II heavy chain in the budding yeast Saccharomyces cerevisiae. Mlc1 defines an essential hub that coordinates actomyosin ring function, membrane trafficking, and septum formation during cytokinesis by binding to IQGAP, myosin‑II, and myosin‑V. However, the mechanism of how Mlc1 is targeted to the division site during the cell cycle remains unsolved. By constructing a GFP‑tagged MLC1 under its own promoter control and using quantitative live‑cell imaging coupled with yeast mutants, we found that septin ring and actin filaments mediate the targeting of Mlc1 to the division site before and during cytokinesis, respectively. Both mechanisms contribute to and are collectively required for the accumulation of Mlc1 at the division site during cytokinesis. We also found that Myo1 plays a major role in the septin‑dependent Mlc1 localization before cytokinesis, whereas the formin Bni1 plays a major role in the actin filament-dependent Mlc1 localization during cytokinesis. Such a two‑tiered mechanism for Mlc1 localization is presumably required for the ordered assembly and robustness of cytokinesis machinery and is likely conserved across species.
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Affiliation(s)
- Zhonghui Feng
- School of Life Sciences, Tsinghua University, Beijing 100084, China Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Satoshi Okada
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Guoping Cai
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Bing Zhou
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Erfei Bi
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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43
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Moravcevic K, Alvarado D, Schmitz KR, Kenniston JA, Mendrola JM, Ferguson KM, Lemmon MA. Comparison of Saccharomyces cerevisiae F-BAR domain structures reveals a conserved inositol phosphate binding site. Structure 2015; 23:352-63. [PMID: 25620000 DOI: 10.1016/j.str.2014.12.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 11/29/2014] [Accepted: 12/02/2014] [Indexed: 12/27/2022]
Abstract
F-BAR domains control membrane interactions in endocytosis, cytokinesis, and cell signaling. Although they are generally thought to bind curved membranes containing negatively charged phospholipids, numerous functional studies argue that differences in lipid-binding selectivities of F-BAR domains are functionally important. Here, we compare membrane-binding properties of the Saccharomyces cerevisiae F-BAR domains in vitro and in vivo. Whereas some F-BAR domains (such as Bzz1p and Hof1p F-BARs) bind equally well to all phospholipids, the F-BAR domain from the RhoGAP Rgd1p preferentially binds phosphoinositides. We determined X-ray crystal structures of F-BAR domains from Hof1p and Rgd1p, the latter bound to an inositol phosphate. The structures explain phospholipid-binding selectivity differences and reveal an F-BAR phosphoinositide binding site that is fully conserved in a mammalian RhoGAP called Gmip and is partly retained in certain other F-BAR domains. Our findings reveal previously unappreciated determinants of F-BAR domain lipid-binding specificity and provide a basis for its prediction from sequence.
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Affiliation(s)
- Katarina Moravcevic
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA; Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
| | - Diego Alvarado
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
| | - Karl R Schmitz
- Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA; Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
| | - Jon A Kenniston
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
| | - Jeannine M Mendrola
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
| | - Kathryn M Ferguson
- Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA; Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA
| | - Mark A Lemmon
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA; Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19014, USA.
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Kita A, Higa M, Doi A, Satoh R, Sugiura R. Imp2, the PSTPIP homolog in fission yeast, affects sensitivity to the immunosuppressant FK506 and membrane trafficking in fission yeast. Biochem Biophys Res Commun 2015; 457:273-9. [PMID: 25580011 DOI: 10.1016/j.bbrc.2014.12.100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 12/22/2014] [Indexed: 11/18/2022]
Abstract
Cytokinesis is a highly ordered process that divides one cell into two cells, which is functionally linked to the dynamic remodeling of the plasma membrane coordinately with various events such as membrane trafficking. Calcineurin is a highly conserved serine/threonine protein phosphatase, which regulates multiple biological functions, such as membrane trafficking and cytokinesis. Here, we isolated imp2-c3, a mutant allele of the imp2(+) gene, encoding a homolog of the mouse PSTPIP1 (proline-serine-threonine phosphatase interacting protein 1), using a genetic screen for mutations that are synthetically lethal with calcineurin deletion in fission yeast. The imp2-c3 mutants showed a defect in cytokinesis with multi-septated phenotypes, which was further enhanced upon treatment with the calcineurin inhibitor FK506. Notably, electron micrographs revealed that the imp2-c3 mutant cells accumulated aberrant multi-lamella Golgi structures and putative post-Golgi secretory vesicles, and exhibited fragmented vacuoles in addition to thickened septa. Consistently, imp2-c3 mutants showed a reduced secretion of acid phosphatase and defects in vacuole fusion. The imp2-c3 mutant cells exhibited a weakened cell wall, similar to the membrane trafficking mutants identified in the same genetic screen such as ypt3-i5. These findings implicate the PSTPIP1 homolog Imp2 in Golgi/vacuole function, thereby affecting various cellular processes, including cytokinesis and cell integrity.
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Affiliation(s)
- Ayako Kita
- Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
| | - Mari Higa
- Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
| | - Akira Doi
- Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan; Japan Society for the Promotion of Science, 1-8 Chiyoda-ku, Tokyo 102-8472, Japan
| | - Ryosuke Satoh
- Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan
| | - Reiko Sugiura
- Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan.
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45
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Zheng Y, Guo J, Li X, Xie Y, Hou M, Fu X, Dai S, Diao R, Miao Y, Ren J. An integrated overview of spatiotemporal organization and regulation in mitosis in terms of the proteins in the functional supercomplexes. Front Microbiol 2014; 5:573. [PMID: 25400627 PMCID: PMC4212687 DOI: 10.3389/fmicb.2014.00573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/11/2014] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic cells may divide via the critical cellular process of cell division/mitosis, resulting in two daughter cells with the same genetic information. A large number of dedicated proteins are involved in this process and spatiotemporally assembled into three distinct super-complex structures/organelles, including the centrosome/spindle pole body, kinetochore/centromere and cleavage furrow/midbody/bud neck, so as to precisely modulate the cell division/mitosis events of chromosome alignment, chromosome segregation and cytokinesis in an orderly fashion. In recent years, many efforts have been made to identify the protein components and architecture of these subcellular organelles, aiming to uncover the organelle assembly pathways, determine the molecular mechanisms underlying the organelle functions, and thereby provide new therapeutic strategies for a variety of diseases. However, the organelles are highly dynamic structures, making it difficult to identify the entire components. Here, we review the current knowledge of the identified protein components governing the organization and functioning of organelles, especially in human and yeast cells, and discuss the multi-localized protein components mediating the communication between organelles during cell division.
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Affiliation(s)
- Yueyuan Zheng
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Junjie Guo
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Xu Li
- Orthopaedic Department of Anhui Medical University Affiliated Provincial Hospital Hefei, China
| | - Yubin Xie
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Mingming Hou
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Xuyang Fu
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Shengkun Dai
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Rucheng Diao
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Yanyan Miao
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
| | - Jian Ren
- Cancer Center, School of Life Sciences, School of Advanced Computing, Cooperative Innovation Center for High Performance Computing, Sun Yat-sen University Guangzhou, China
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46
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Rippert D, Heppeler N, Albermann S, Schmitz HP, Heinisch JJ. Regulation of cytokinesis in the milk yeast Kluyveromyces lactis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2685-97. [PMID: 25110348 DOI: 10.1016/j.bbamcr.2014.07.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 10/24/2022]
Abstract
Cytokinesis in yeast and mammalian cells is a highly coordinated process mediated by the constriction of an actomyosin ring. In yeasts, it is accompanied by the formation of a chitinous primary septum. Although much is known about the regulation of cytokinesis in budding yeast, overlapping functions of redundant genes complicates genetic analyses. Here, we investigated the effects of various deletion mutants on cytokinesis in the milk yeast Kluyveromyces lactis. To determine the spatiotemporal parameters of cytokinesis components, live-cell imaging of fluorophor-tagged KlMyo1 and a new Lifeact probe for KlAct1 was employed. In contrast to Saccharomyces cerevisiae, where deletion of ScMYO1 is lethal, Klmyo1 deletion was temperature-sensitive. Transmission and scanning electron microscopy demonstrated that the Klmyo1 deletion cells had a defect in the formation of the primary septum and in cell separation; this result was confirmed by FACS analyses. Deletion of KlCYK3 was lethal, whereas in S. cerevisiae a cyk3 deletion is synthetically lethal with hof1 deletion. Growth of Klhof1 mutants was osmoremedial at 25°C, as it is in S. cerevisiae. CYK3 and HOF1 genes cross-complemented in both species, suggesting that they are functional homologs. Inn1, a common interactor for these two regulators, was essential in both yeasts and the encoding genes did not cross-complement. The C2 domain of the Inn1 homologs conferred species specificity. Thus, our work establishes K. lactis as a model yeast to study cytokinesis with less genetic redundancy than S. cerevisiae. The viability of Klmyo1 deletions provides an advantage over budding yeast to study actomyosin-independent cytokinesis. Moreover, the lethality of Klcyk3 null mutants suggests that there are fewer functional redundancies with KlHof1 in K. lactis.
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Affiliation(s)
- Dorthe Rippert
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, 49076 Osnabrück, Germany
| | - Nele Heppeler
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, 49076 Osnabrück, Germany
| | - Sabine Albermann
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, 49076 Osnabrück, Germany
| | - Hans-Peter Schmitz
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, 49076 Osnabrück, Germany
| | - Jürgen J Heinisch
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, 49076 Osnabrück, Germany.
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47
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Tian C, Wu Y, Johnsson N. Stepwise and cooperative assembly of a cytokinetic core complex in Saccharomyces cerevisiae. J Cell Sci 2014; 127:3614-24. [PMID: 24895401 DOI: 10.1242/jcs.153429] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Actomyosin ring (AMR) contraction and the synthesis of an extracellular septum are interdependent pathways that mediate cytokinesis in the yeast Saccharomyces cerevisiae and other eukaryotes. How these interdependent pathways are physically connected is central for understanding cytokinesis. The yeast IQGAP (Iqg1p) belongs to the conserved AMR. The F-BAR-domain-containing protein Hof1p is a member of a complex that stimulates cell wall synthesis. We report here on the stepwise formation of a physical connection between both proteins. The C-terminal IQ-repeats of Iqg1p first bind to the essential myosin light chain before both proteins assemble with Hof1p into the Mlc1p-Iqg1p-Hof1p (MIH) bridge. Mutations in Iqg1p that disrupt the MIH complex alter Hof1p targeting to the AMR and impair AMR contraction. Epistasis analyses of two IQG1 alleles that are incompatible with formation of the MIH complex support the existence and functional significance of a large cytokinetic core complex. We propose that the MIH complex acts as hinge between the AMR and the proteins involved in cell wall synthesis and membrane attachment.
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Affiliation(s)
- Chen Tian
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, James-Franck-Ring N27, 89081 Ulm, Germany
| | - Yehui Wu
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, James-Franck-Ring N27, 89081 Ulm, Germany
| | - Nils Johnsson
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, James-Franck-Ring N27, 89081 Ulm, Germany
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48
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Graziano BR, Yu HYE, Alioto SL, Eskin JA, Ydenberg CA, Waterman DP, Garabedian M, Goode BL. The F-BAR protein Hof1 tunes formin activity to sculpt actin cables during polarized growth. Mol Biol Cell 2014; 25:1730-43. [PMID: 24719456 PMCID: PMC4038500 DOI: 10.1091/mbc.e14-03-0850] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 04/03/2014] [Indexed: 11/23/2022] Open
Abstract
Asymmetric cell growth and division rely on polarized actin cytoskeleton remodeling events, the regulation of which is poorly understood. In budding yeast, formins stimulate the assembly of an organized network of actin cables that direct polarized secretion. Here we show that the Fer/Cip4 homology-Bin amphiphysin Rvs protein Hof1, which has known roles in cytokinesis, also functions during polarized growth by directly controlling the activities of the formin Bnr1. A mutant lacking the C-terminal half of Hof1 displays misoriented and architecturally altered cables, along with impaired secretory vesicle traffic. In vitro, Hof1 inhibits the actin nucleation and elongation activities of Bnr1 without displacing the formin from filament ends. These effects depend on the Src homology 3 domain of Hof1, the formin homology 1 (FH1) domain of Bnr1, and Hof1 dimerization, suggesting a mechanism by which Hof1 "restrains" the otherwise flexible FH1-FH2 apparatus. In vivo, loss of inhibition does not alter actin levels in cables but, instead, cable shape and functionality. Thus Hof1 tunes formins to sculpt the actin cable network.
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Affiliation(s)
- Brian R Graziano
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
| | - Hoi-Ying E Yu
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
| | - Salvatore L Alioto
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
| | - Julian A Eskin
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
| | - Casey A Ydenberg
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
| | - David P Waterman
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
| | - Mikael Garabedian
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
| | - Bruce L Goode
- Department of Biology and Rosenstiel Basic Medical Science Research Center, Brandeis University, Waltham, MA 02454
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49
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Kang X, Jiang L, Chen X, Yuan H, Luo C, Ouyang Q. Pump-free multi-well-based microfluidic system for high-throughput analysis of size-control relative genes in budding yeast. Integr Biol (Camb) 2014; 6:685-93. [PMID: 24872017 DOI: 10.1039/c4ib00054d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-lapse single cell imaging by microscopy can provide precise cell information such as the cell size, the cell cycle duration, protein localization and protein expression level. Usually, a microfluidic system is needed for these measurements in order to provide a constant culture environment and confine the cells so that they grow in a monolayer. However, complex connections are required between the channels inside the chip and the outside media, and a complex procedure is needed for loading of cells, thereby making this type of system unsuitable for application in high-throughput single cell scanning experiments. Here we provide a novel and easily operated pump-free multi-well-based microfluidic system which enables the high-throughput loading of many different budding yeast strains into monolayer growth conditions just by use of a multi-channel pipette. Wild type budding yeast (Saccharomyces cerevisiae) and 62 different budding yeast size control relative gene deletion strains were chosen for scanning. We obtained normalized statistical results for the mother cell doubling time, daughter cell doubling time, mother cell size and daughter cell size of different gene deletion strains relative to the corresponding parameters of the wild type cells. Meanwhile, we compared the typical cell morphology of different strains and analyzed the relationship between the cell genotype and phenotype. This method which can be easily used in a normal biology lab may help researchers who need to carry out the high-throughput scanning of cell morphology and growth.
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Affiliation(s)
- Xianjie Kang
- The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, China.
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Cundell MJ, Price C. The budding yeast amphiphysin complex is required for contractile actin ring (CAR) assembly and post-contraction GEF-independent accumulation of Rho1-GTP. PLoS One 2014; 9:e97663. [PMID: 24874185 PMCID: PMC4038553 DOI: 10.1371/journal.pone.0097663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/22/2014] [Indexed: 12/26/2022] Open
Abstract
The late events of the budding yeast cell division cycle, cytokinesis and cell separation, require the assembly of a contractile actomyosin ring (CAR), primary and secondary septum formation followed by enzymatic degradation of the primary septum. Here we present evidence that demonstrates a role for the budding yeast amphiphysin complex, a heterodimer comprising Rvs167 and Rvs161, in CAR assembly and cell separation. The iqg1-1 allele is synthetically lethal with both rvs167 and rvs161 null mutations. We show that both Iqg1 and the amphiphysin complex are required for CAR assembly in early anaphase but cells are able to complete assembly in late anaphase when these activities are, respectively, either compromised or absent. Amphiphysin dependent CAR assembly is dependent upon the Rvs167 SH3 domain, but this function is insufficient to explain the observed synthetic lethality. Dosage suppression of the iqg1-1 allele demonstrates that endocytosis is required for the default cell separation pathway in the absence of CAR contraction but is unlikely to be required to maintain viability. The amphiphysin complex is required for normal, post-mitotic, localization of Chs3 and the Rho1 GEF, Rom2, which are responsible for secondary septum deposition and the accumulation of GTP bound Rho1 at the bud neck. It is concluded that a failure of polarity establishment in the absence of CAR contraction and amphiphysin function leads to loss of viability as a result of the consequent cell separation defect.
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Affiliation(s)
- Michael John Cundell
- School of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster, United Kingdom
| | - Clive Price
- School of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster, United Kingdom
- * E-mail:
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