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Chen JS, Igarashi MG, Ren L, Hanna SM, Turner LA, McDonald NA, Beckley JR, Willet AH, Gould KL. The core spindle pole body scaffold Ppc89 links the pericentrin orthologue Pcp1 to the fission yeast spindle pole body via an evolutionarily conserved interface. Mol Biol Cell 2024; 35:ar112. [PMID: 38985524 PMCID: PMC11321043 DOI: 10.1091/mbc.e24-05-0220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 06/26/2024] [Accepted: 07/02/2024] [Indexed: 07/12/2024] Open
Abstract
Centrosomes and spindle pole bodies (SPBs) are important for mitotic spindle formation and serve as cellular signaling platforms. Although centrosomes and SPBs differ in morphology, many mechanistic insights into centrosome function have been gleaned from SPB studies. In the fission yeast Schizosaccharomyces pombe, the α-helical protein Ppc89, identified based on its interaction with the septation initiation network scaffold Sid4, comprises the SPB core. High-resolution imaging has suggested that SPB proteins assemble on the Ppc89 core during SPB duplication, but such interactions are undefined. Here, we define a connection between Ppc89 and the essential pericentrin Pcp1. Specifically, we found that a predicted third helix within Ppc89 binds the Pcp1 pericentrin-AKAP450 centrosomal targeting (PACT) domain complexed with calmodulin. Ppc89 helix 3 contains similarity to present in the N-terminus of Cep57 (PINC) motifs found in the centrosomal proteins fly SAS-6 and human Cep57 and also to the S. cerevisiae SPB protein Spc42. These motifs bind pericentrin-calmodulin complexes and AlphaFold2 models suggest a homologous complex assembles in all four organisms. Mutational analysis of the S. pombe complex supports the importance of Ppc89-Pcp1 binding interface in vivo. Our studies provide insight into the core architecture of the S. pombe SPB and suggest an evolutionarily conserved mechanism of scaffolding pericentrin-calmodulin complexes for mitotic spindle formation.
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Affiliation(s)
- Jun-Song Chen
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Maya G. Igarashi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Liping Ren
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Sarah M. Hanna
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Lesley A. Turner
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Nathan A. McDonald
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Janel R. Beckley
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Alaina H. Willet
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Kathleen L. Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
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2
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Vojnovic I, Caspari OD, Hoşkan MA, Endesfelder U. Combining single-molecule and expansion microscopy in fission yeast to visualize protein structures at the nanostructural level. Open Biol 2024; 14:230414. [PMID: 38320620 PMCID: PMC10846934 DOI: 10.1098/rsob.230414] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/04/2023] [Indexed: 02/08/2024] Open
Abstract
In this work, we have developed an expansion microscopy (ExM) protocol that combines ExM with photoactivated localization microscopy (ExPALM) for yeast cell imaging, and report a robust protocol for single-molecule and expansion microscopy of fission yeast, abbreviated as SExY. Our optimized SExY protocol retains about 50% of the fluorescent protein signal, doubling the amount obtained compared to the original protein retention ExM (proExM) protocol. It allows for a fivefold, highly isotropic expansion of fission yeast cells, which we carefully controlled while optimizing protein yield. We demonstrate the SExY method on several exemplary molecular targets and explicitly introduce low-abundant protein targets (e.g. nuclear proteins such as cbp1 and mis16, and the centromere-specific histone protein cnp1). The SExY protocol optimizations increasing protein yield could be beneficial for many studies, when targeting low abundance proteins, or for studies that rely on genetic labelling for various reasons (e.g. for proteins that cannot be easily targeted by extrinsic staining or in case artefacts introduced by unspecific staining interfere with data quality).
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Affiliation(s)
- Ilijana Vojnovic
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Oliver D. Caspari
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
- Department of Microbiology, Institute Pasteur, Paris, France
| | - Mehmet Ali Hoşkan
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Ulrike Endesfelder
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
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3
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Fernández-Álvarez A. Beyond tradition: exploring the non-canonical functions of telomeres in meiosis. Front Cell Dev Biol 2023; 11:1278571. [PMID: 38020928 PMCID: PMC10679444 DOI: 10.3389/fcell.2023.1278571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
The telomere bouquet is a specific chromosomal configuration that forms during meiosis at the zygotene stage, when telomeres cluster together at the nuclear envelope. This clustering allows cytoskeleton-induced movements to be transmitted to the chromosomes, thereby facilitating homologous chromosome search and pairing. However, loss of the bouquet results in more severe meiotic defects than can be attributed solely to recombination problems, suggesting that the bouquet's full function remains elusive. Despite its transient nature and the challenges in performing in vivo analyses, information is emerging that points to a remarkable suite of non-canonical functions carried out by the bouquet. Here, we describe how new approaches in quantitative cell biology can contribute to establishing the molecular basis of the full function and plasticity of the bouquet, and thus generate a comprehensive picture of the telomeric control of meiosis.
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Affiliation(s)
- Alfonso Fernández-Álvarez
- Institute of Functional Biology and Genomics (IBFG), Consejo Superior de Investigaciones Científicas (CSIC), University of Salamanca, Salamanca, Spain
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4
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London N, Medina-Pritchard B, Spanos C, Rappsilber J, Jeyaprakash AA, Allshire RC. Direct recruitment of Mis18 to interphase spindle pole bodies promotes CENP-A chromatin assembly. Curr Biol 2023; 33:4187-4201.e6. [PMID: 37714149 DOI: 10.1016/j.cub.2023.08.063] [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: 06/21/2023] [Revised: 08/04/2023] [Accepted: 08/22/2023] [Indexed: 09/17/2023]
Abstract
CENP-A chromatin specifies mammalian centromere identity, and its chaperone HJURP replenishes CENP-A when recruited by the Mis18 complex (Mis18C) via M18BP1/KNL2 to CENP-C at kinetochores during interphase. However, the Mis18C recruitment mechanism remains unresolved in species lacking M18BP1, such as fission yeast. Fission yeast centromeres cluster at G2 spindle pole bodies (SPBs) when CENP-ACnp1 is replenished and where Mis18C also localizes. We show that SPBs play an unexpected role in concentrating Mis18C near centromeres through the recruitment of Mis18 by direct binding to the major SPB linker of nucleoskeleton and cytoskeleton (LINC) component Sad1. Mis18C recruitment by Sad1 is important for CENP-ACnp1 chromatin establishment and acts in parallel with a CENP-C-mediated Mis18C recruitment pathway to maintain centromeric CENP-ACnp1 but operates independently of Sad1-mediated centromere clustering. SPBs therefore provide a non-chromosomal scaffold for both Mis18C recruitment and centromere clustering during G2. This centromere-independent Mis18-SPB recruitment provides a mechanism that governs de novo CENP-ACnp1 chromatin assembly by the proximity of appropriate sequences to SPBs and highlights how nuclear spatial organization influences centromere identity.
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Affiliation(s)
- Nitobe London
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Bethan Medina-Pritchard
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Christos Spanos
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Juri Rappsilber
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK; Institute of Biotechnology, Technische Universität, 13355 Berlin, Germany
| | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK; Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK.
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5
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Mitic K, Meyer I, Gräf R, Grafe M. Temporal Changes in Nuclear Envelope Permeability during Semi-Closed Mitosis in Dictyostelium Amoebae. Cells 2023; 12:1380. [PMID: 37408214 DOI: 10.3390/cells12101380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 07/07/2023] Open
Abstract
The Amoebozoan Dictyostelium discoideum exhibits a semi-closed mitosis in which the nuclear membranes remain intact but become permeabilized to allow tubulin and spindle assembly factors to access the nuclear interior. Previous work indicated that this is accomplished at least by partial disassembly of nuclear pore complexes (NPCs). Further contributions by the insertion process of the duplicating, formerly cytosolic, centrosome into the nuclear envelope and nuclear envelope fenestrations forming around the central spindle during karyokinesis were discussed. We studied the behavior of several Dictyostelium nuclear envelope, centrosomal, and nuclear pore complex (NPC) components tagged with fluorescence markers together with a nuclear permeabilization marker (NLS-TdTomato) by live-cell imaging. We could show that permeabilization of the nuclear envelope during mitosis occurs in synchrony with centrosome insertion into the nuclear envelope and partial disassembly of nuclear pore complexes. Furthermore, centrosome duplication takes place after its insertion into the nuclear envelope and after initiation of permeabilization. Restoration of nuclear envelope integrity usually occurs long after re-assembly of NPCs and cytokinesis has taken place and is accompanied by a concentration of endosomal sorting complex required for transport (ESCRT) components at both sites of nuclear envelope fenestration (centrosome and central spindle).
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Affiliation(s)
- Kristina Mitic
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Irene Meyer
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Ralph Gräf
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Marianne Grafe
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
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6
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Hinterndorfer K, Laporte MH, Mikus F, Tafur L, Bourgoint C, Prouteau M, Dey G, Loewith R, Guichard P, Hamel V. Ultrastructure expansion microscopy reveals the cellular architecture of budding and fission yeast. J Cell Sci 2022; 135:286062. [PMID: 36524422 PMCID: PMC10112979 DOI: 10.1242/jcs.260240] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 11/18/2022] [Indexed: 12/23/2022] Open
Abstract
ABSTRACT
The budding and fission yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe have served as invaluable model organisms to study conserved fundamental cellular processes. Although super-resolution microscopy has in recent years paved the way to a better understanding of the spatial organization of molecules in cells, its wide use in yeasts has remained limited due to the specific know-how and instrumentation required, contrasted with the relative ease of endogenous tagging and live-cell fluorescence microscopy. To facilitate super-resolution microscopy in yeasts, we have extended the ultrastructure expansion microscopy (U-ExM) method to both S. cerevisiae and S. pombe, enabling a 4-fold isotropic expansion. We demonstrate that U-ExM allows imaging of the microtubule cytoskeleton and its associated spindle pole body, notably unveiling the Sfi1p–Cdc31p spatial organization on the appendage bridge structure. In S. pombe, we validate the method by monitoring the homeostatic regulation of nuclear pore complex number through the cell cycle. Combined with NHS-ester pan-labelling, which provides a global cellular context, U-ExM reveals the subcellular organization of these two yeast models and provides a powerful new method to augment the already extensive yeast toolbox.
This article has an associated First Person interview with Kerstin Hinterndorfer and Felix Mikus, two of the joint first authors of the paper.
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Affiliation(s)
- Kerstin Hinterndorfer
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
| | - Marine H. Laporte
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
| | - Felix Mikus
- European Molecular Biology Laboratory 2 Cell Biology and Biophysics , , Heidelberg , Germany
| | - Lucas Tafur
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
| | - Clélia Bourgoint
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
| | - Manoel Prouteau
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
| | - Gautam Dey
- European Molecular Biology Laboratory 2 Cell Biology and Biophysics , , Heidelberg , Germany
| | - Robbie Loewith
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
| | - Paul Guichard
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
| | - Virginie Hamel
- University of Geneva 1 Department of Molecular and Cellular Biology , , Geneva , Switzerland
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7
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Laporte MH, Bouhlel IB, Bertiaux E, Morrison CG, Giroud A, Borgers S, Azimzadeh J, Bornens M, Guichard P, Paoletti A, Hamel V. Human SFI1 and Centrin form a complex critical for centriole architecture and ciliogenesis. EMBO J 2022; 41:e112107. [PMID: 36125182 DOI: 10.15252/embj.2022112107] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/23/2022] [Accepted: 09/02/2022] [Indexed: 11/09/2022] Open
Abstract
Over the course of evolution, the centrosome function has been conserved in most eukaryotes, but its core architecture has evolved differently in some clades, with the presence of centrioles in humans and a spindle pole body (SPB) in yeast. Similarly, the composition of these two core elements has diverged, with the exception of Centrin and SFI1, which form a complex in yeast to initiate SPB duplication. However, it remains unclear whether this complex exists at centrioles and whether its function has been conserved. Here, using expansion microscopy, we demonstrate that human SFI1 is a centriolar protein that associates with a pool of Centrin at the distal end of the centriole. We also find that both proteins are recruited early during procentriole assembly and that depletion of SFI1 results in the loss of the distal pool of Centrin, without altering centriole duplication. Instead, we show that SFI1/Centrin complex is essential for centriolar architecture, CEP164 distribution, and CP110 removal during ciliogenesis. Together, our work reveals a conserved SFI1/Centrin module displaying divergent functions between mammals and yeast.
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Affiliation(s)
- Marine H Laporte
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Imène B Bouhlel
- Institut Curie, UMR 144, CNRS, PSL University, Paris, France
| | - Eloïse Bertiaux
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Ciaran G Morrison
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.,Centre for Chromosome Biology, School of Biological and Chemical Sciences, National University of Ireland Galway, Galway, Ireland
| | - Alexia Giroud
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Susanne Borgers
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | | | - Michel Bornens
- Institut Curie, UMR 144, CNRS, PSL University, Paris, France
| | - Paul Guichard
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Anne Paoletti
- Institut Curie, UMR 144, CNRS, PSL University, Paris, France
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
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8
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Wu W, McHugh T, Kelly DA, Pidoux AL, Allshire RC. Establishment of centromere identity is dependent on nuclear spatial organization. Curr Biol 2022; 32:3121-3136.e6. [PMID: 35830853 PMCID: PMC9616734 DOI: 10.1016/j.cub.2022.06.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 04/24/2022] [Accepted: 06/15/2022] [Indexed: 11/15/2022]
Abstract
The establishment of centromere-specific CENP-A chromatin is influenced by epigenetic and genetic processes. Central domain sequences from fission yeast centromeres are preferred substrates for CENP-ACnp1 incorporation, but their use is context dependent, requiring adjacent heterochromatin. CENP-ACnp1 overexpression bypasses heterochromatin dependency, suggesting that heterochromatin ensures exposure to conditions or locations permissive for CENP-ACnp1 assembly. Centromeres cluster around spindle-pole bodies (SPBs). We show that heterochromatin-bearing minichromosomes localize close to SPBs, consistent with this location promoting CENP-ACnp1 incorporation. We demonstrate that heterochromatin-independent de novo CENP-ACnp1 chromatin assembly occurs when central domain DNA is placed near, but not far from, endogenous centromeres or neocentromeres. Moreover, direct tethering of central domain DNA at SPBs permits CENP-ACnp1 assembly, suggesting that the nuclear compartment surrounding SPBs is permissive for CENP-ACnp1 incorporation because target sequences are exposed to high levels of CENP-ACnp1 and associated assembly factors. Thus, nuclear spatial organization is a key epigenetic factor that influences centromere identity.
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Affiliation(s)
- Weifang Wu
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Toni McHugh
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - David A Kelly
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Alison L Pidoux
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK.
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9
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Gavade JN, Black BE. Chromosomes: A nuclear neighborhood conducive to centromere formation. Curr Biol 2022; 32:R776-R778. [PMID: 35882197 DOI: 10.1016/j.cub.2022.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Centromere identity is specified by nucleosomes containing the histone variant CENP-A. A new study reveals that subnuclear location dictates the efficiency with which a new centromere forms.
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Affiliation(s)
- Janardan N Gavade
- Department of Biochemistry and Biophysics, Penn Center for Genome Integrity, Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ben E Black
- Department of Biochemistry and Biophysics, Penn Center for Genome Integrity, Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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10
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Langlois-Lemay L, D’Amours D. Moonlighting at the Poles: Non-Canonical Functions of Centrosomes. Front Cell Dev Biol 2022; 10:930355. [PMID: 35912107 PMCID: PMC9329689 DOI: 10.3389/fcell.2022.930355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/17/2022] [Indexed: 11/13/2022] Open
Abstract
Centrosomes are best known as the microtubule organizing centers (MTOCs) of eukaryotic cells. In addition to their classic role in chromosome segregation, centrosomes play diverse roles unrelated to their MTOC activity during cell proliferation and quiescence. Metazoan centrosomes and their functional doppelgängers from lower eukaryotes, the spindle pole bodies (SPBs), act as important structural platforms that orchestrate signaling events essential for cell cycle progression, cellular responses to DNA damage, sensory reception and cell homeostasis. Here, we provide a critical overview of the unconventional and often overlooked roles of centrosomes/SPBs in the life cycle of eukaryotic cells.
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Affiliation(s)
- Laurence Langlois-Lemay
- Department of Cellular and Molecular Medicine, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
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11
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Varberg JM, Unruh JR, Bestul AJ, Khan AA, Jaspersen SL. Quantitative analysis of nuclear pore complex organization in Schizosaccharomyces pombe. Life Sci Alliance 2022; 5:5/7/e202201423. [PMID: 35354597 PMCID: PMC8967992 DOI: 10.26508/lsa.202201423] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 01/06/2023] Open
Abstract
Characterization of nuclear pores in Schizosaccharomyces pombe identifies regions of heterogeneous NPC density and composition and shows that NPCs are excluded near the spindle pole body by Lem2-mediated centromere tethering. The number, distribution, and composition of nuclear pore complexes (NPCs) in the nuclear envelope varies between cell types and changes during cellular differentiation and in disease. To understand how NPC density and organization are controlled, we analyzed the NPC number and distribution in the fission yeast Schizosaccharomyces pombe using structured illumination microscopy. The small size of yeast nuclei, genetic features of fungi, and our robust image analysis pipeline allowed us to study NPCs in intact nuclei under multiple conditions. Our data revealed that NPC density is maintained across a wide range of nuclear sizes. Regions of reduced NPC density are observed over the nucleolus and surrounding the spindle pole body (SPB). Lem2-mediated tethering of the centromeres to the SPB is required to maintain NPC exclusion near SPBs. These findings provide a quantitative understanding of NPC number and distribution in S. pombe and show that interactions between the centromere and the nuclear envelope influences local NPC distribution.
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Affiliation(s)
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Andrew J Bestul
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Azqa A Khan
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO, USA .,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
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12
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Zhu Q, Jiang Z, He X. Pcp1/pericentrin controls the SPB number in fission yeast meiosis and ploidy homeostasis. J Cell Biol 2022; 221:212751. [PMID: 34747981 PMCID: PMC8579193 DOI: 10.1083/jcb.202104099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 08/31/2021] [Accepted: 10/13/2021] [Indexed: 11/22/2022] Open
Abstract
During sexual reproduction, the zygote must inherit exactly one centrosome (spindle pole body [SPB] in yeasts) from the gametes, which then duplicates and assembles a bipolar spindle that supports the subsequent cell division. Here, we show that in the fission yeast Schizosaccharomyces pombe, the fusion of SPBs from the gametes is blocked in polyploid zygotes. As a result, the polyploid zygotes cannot proliferate mitotically and frequently form supernumerary SPBs during subsequent meiosis, which leads to multipolar nuclear divisions and the generation of extra spores. The blockage of SPB fusion is caused by persistent SPB localization of Pcp1, which, in normal diploid zygotic meiosis, exhibits a dynamic association with the SPB. Artificially induced constitutive localization of Pcp1 on the SPB is sufficient to cause blockage of SPB fusion and formation of extra spores in diploids. Thus, Pcp1-dependent SPB quantity control is crucial for sexual reproduction and ploidy homeostasis in fission yeast.
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Affiliation(s)
- Qian Zhu
- The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Zhaodi Jiang
- National Institute of Biological Sciences, Beijing, China
| | - Xiangwei He
- The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, China
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13
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Computerized fluorescence microscopy of microbial cells. World J Microbiol Biotechnol 2021; 37:189. [PMID: 34617135 DOI: 10.1007/s11274-021-03159-3] [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: 07/27/2021] [Accepted: 09/30/2021] [Indexed: 10/20/2022]
Abstract
The upgrading of fluorescence microscopy by the introduction of computer technologies has led to the creation of a new methodology, computerized fluorescence microscopy (CFM). CFM improves subjective visualization and combines it with objective quantitative analysis of the microscopic data. CFM has opened up two fundamentally new opportunities for studying microorganisms. The first is the quantitative measurement of the fluorescence parameters of the targeted fluorophores in association with certain structures of individual cells. The second is the expansion of the boundaries of visualization/resolution of intracellular components beyond the "diffraction limit" of light microscopy into the nanometer range. This enables to obtain unique information about the localization and dynamics of intracellular processes at the molecular level. The purpose of this review is to demonstrate the potential of CFM in the study of fundamental aspects of the structural and functional organization of microbial cells. The basics of computer processing and analysis of digital images are briefly described. The fluorescent molecules used in CFM with an emphasis on fluorescent proteins are characterized. The main methods of super-resolution microscopy (nanoscopy) are presented. The capabilities of various CFM methods for exploring microbial cells at the subcellular level are illustrated by the examples of various studies on yeast and bacteria.
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14
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Saha S, Unruh JR, Jaspersen SL. Distribution of γ-tubulin ring complex at the Schizosaccharomyces pombe spindle pole. MICROPUBLICATION BIOLOGY 2021; 2021:10.17912/micropub.biology.000464. [PMID: 35622906 PMCID: PMC9015813 DOI: 10.17912/micropub.biology.000464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/31/2021] [Accepted: 09/06/2021] [Indexed: 11/12/2022]
Abstract
Microtubule nucleation is mediated by the conserved γ-tubulin ring complex (γ-TuRC). Using super-resolution microscopy, we investigate the distribution of γ-TuRC components at the spindle pole body (SPB) in wild-type
Schizosaccharomyces pombe
. We observed asymmetric distribution of γ-TuRC on its nuclear and cytoplasmic surfaces, consistent with the uneven distribution of microtubules. Examination of deletion mutants in the three non-essential γ-TuRC subunits showed defects in γ-TuRC accumulation on the old and new SPB, particularly in cells lacking
alp16+
(the Gcp6 ortholog) that may explain the monopolar spindles observed in this mutant upon mitotic entry.
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Affiliation(s)
| | | | - Sue L Jaspersen
- Stowers Institute for Medical Research
,
Department of Molecular & Integrative Physiology, University of Kansas Medical Center
,
Correspondence to: Sue L Jaspersen (
)
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15
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Pineda-Santaella A, Fernández-Castillo N, Jiménez-Martín A, Macías-Cabeza MDC, Sánchez-Gómez Á, Fernández-Álvarez A. Loss of kinesin-8 improves the robustness of the self-assembled spindle in Schizosaccharomyces pombe. J Cell Sci 2021; 134:271184. [PMID: 34346498 PMCID: PMC8435293 DOI: 10.1242/jcs.253799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 07/19/2021] [Indexed: 11/30/2022] Open
Abstract
Chromosome segregation in female meiosis in many metazoans is mediated by acentrosomal spindles, the existence of which implies that microtubule spindles self-assemble without the participation of the centrosomes. Although it is thought that acentrosomal meiosis is not conserved in fungi, we recently reported the formation of self-assembled microtubule arrays, which were able to segregate chromosomes, in fission yeast mutants, in which the contribution of the spindle pole body (SPB; the centrosome equivalent in yeast) was specifically blocked during meiosis. Here, we demonstrate that this unexpected microtubule formation represents a bona fide type of acentrosomal spindle. Moreover, a comparative analysis of these self-assembled spindles and the canonical SPB-dependent spindle reveals similarities and differences; for example, both spindles have a similar polarity, but the location of the γ-tubulin complex differs. We also show that the robustness of self-assembled spindles can be reinforced by eliminating kinesin-8 family members, whereas kinesin-8 mutants have an adverse impact on SPB-dependent spindles. Hence, we consider that reinforced self-assembled spindles in yeast will help to clarify the molecular mechanisms behind acentrosomal meiosis, a crucial step towards better understanding gametogenesis. Summary: We report a comparative analysis of self-assembled spindles and canonical centrosomal spindles in fission yeast, which could clarify the mechanisms underlying acentrosomal meiosis.
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Affiliation(s)
- Alberto Pineda-Santaella
- Andalusian Centre for Developmental Biology (CABD), Universidad Pablo de Olavide - Consejo Superior de Investigaciones Científicas (CSIC), Junta de Andalucía, Ctra. Utrera Km. 4, 41013 Seville, Spain
| | - Nazaret Fernández-Castillo
- Andalusian Centre for Developmental Biology (CABD), Universidad Pablo de Olavide - Consejo Superior de Investigaciones Científicas (CSIC), Junta de Andalucía, Ctra. Utrera Km. 4, 41013 Seville, Spain
| | - Alberto Jiménez-Martín
- Andalusian Centre for Developmental Biology (CABD), Universidad Pablo de Olavide - Consejo Superior de Investigaciones Científicas (CSIC), Junta de Andalucía, Ctra. Utrera Km. 4, 41013 Seville, Spain
| | - María Del Carmen Macías-Cabeza
- Andalusian Centre for Developmental Biology (CABD), Universidad Pablo de Olavide - Consejo Superior de Investigaciones Científicas (CSIC), Junta de Andalucía, Ctra. Utrera Km. 4, 41013 Seville, Spain
| | - Ángela Sánchez-Gómez
- Andalusian Centre for Developmental Biology (CABD), Universidad Pablo de Olavide - Consejo Superior de Investigaciones Científicas (CSIC), Junta de Andalucía, Ctra. Utrera Km. 4, 41013 Seville, Spain
| | - Alfonso Fernández-Álvarez
- Andalusian Centre for Developmental Biology (CABD), Universidad Pablo de Olavide - Consejo Superior de Investigaciones Científicas (CSIC), Junta de Andalucía, Ctra. Utrera Km. 4, 41013 Seville, Spain
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16
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Bestul AJ, Yu Z, Unruh JR, Jaspersen SL. Redistribution of centrosomal proteins by centromeres and Polo kinase controls partial nuclear envelope breakdown in fission yeast. Mol Biol Cell 2021; 32:1487-1500. [PMID: 34133218 PMCID: PMC8351742 DOI: 10.1091/mbc.e21-05-0239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Proper mitotic progression in Schizosaccharomyces pombe requires partial nuclear envelope breakdown (NEBD) and insertion of the spindle pole body (SPB—yeast centrosome) to build the mitotic spindle. Linkage of the centromere to the SPB is vital to this process, but why that linkage is important is not well understood. Utilizing high-resolution structured illumination microscopy, we show that the conserved Sad1-UNC-84 homology-domain protein Sad1 and other SPB proteins redistribute during mitosis to form a ring complex around SPBs, which is a precursor for localized NEBD and spindle formation. Although the Polo kinase Plo1 is not necessary for Sad1 redistribution, it localizes to the SPB region connected to the centromere, and its activity is vital for redistribution of other SPB ring proteins and for complete NEBD at the SPB to allow for SPB insertion. Our results lead to a model in which centromere linkage to the SPB drives redistribution of Sad1 and Plo1 activation that in turn facilitate partial NEBD and spindle formation through building of a SPB ring structure.
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Affiliation(s)
- Andrew J Bestul
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO 64110.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160
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17
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Rüthnick D, Vitale J, Neuner A, Schiebel E. The N-terminus of Sfi1 and yeast centrin Cdc31 provide the assembly site for a new spindle pole body. J Cell Biol 2021; 220:211743. [PMID: 33523111 PMCID: PMC7852455 DOI: 10.1083/jcb.202004196] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 11/20/2020] [Accepted: 12/18/2020] [Indexed: 12/31/2022] Open
Abstract
The spindle pole body (SPB) provides microtubule-organizing functions in yeast and duplicates exactly once per cell cycle. The first step in SPB duplication is the half-bridge to bridge conversion via the antiparallel dimerization of the centrin (Cdc31)-binding protein Sfi1 in anaphase. The bridge, which is anchored to the old SPB on the proximal end, exposes free Sfi1 N-termini (N-Sfi1) at its distal end. These free N-Sfi1 promote in G1 the assembly of the daughter SPB (dSPB) in a yet unclear manner. This study shows that N-Sfi1 including the first three Cdc31 binding sites interacts with the SPB components Spc29 and Spc42, triggering the assembly of the dSPB. Cdc31 binding to N-Sfi1 promotes Spc29 recruitment and is essential for satellite formation. Furthermore, phosphorylation of N-Sfi1 has an inhibitory effect and delays dSPB biogenesis until G1. Taking these data together, we provide an understanding of the initial steps in SPB assembly and describe a new function of Cdc31 in the recruitment of dSPB components.
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Affiliation(s)
- Diana Rüthnick
- Center for Molecular Biology, University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Jlenia Vitale
- Center for Molecular Biology, University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Annett Neuner
- Center for Molecular Biology, University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
| | - Elmar Schiebel
- Center for Molecular Biology, University of Heidelberg, German Cancer Research Center-Center for Molecular Biology Alliance, Heidelberg, Germany
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18
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High-Throughput Identification of Nuclear Envelope Protein Interactions in Schizosaccharomyces pombe Using an Arrayed Membrane Yeast-Two Hybrid Library. G3-GENES GENOMES GENETICS 2020; 10:4649-4663. [PMID: 33109728 PMCID: PMC7718735 DOI: 10.1534/g3.120.401880] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The nuclear envelope (NE) contains a specialized set of integral membrane proteins that maintain nuclear shape and integrity and influence chromatin organization and gene expression. Advances in proteomics techniques and studies in model organisms have identified hundreds of proteins that localize to the NE. However, the function of many of these proteins at the NE remains unclear, in part due to a lack of understanding of the interactions that these proteins participate in at the NE membrane. To assist in the characterization of NE transmembrane protein interactions we developed an arrayed library of integral and peripheral membrane proteins from the fission yeast Schizosaccharomyces pombe for high-throughput screening using the split-ubiquitin based membrane yeast two -hybrid system. We used this approach to characterize protein interactions for three conserved proteins that localize to the inner nuclear membrane: Cut11/Ndc1, Lem2 and Ima1/Samp1/Net5. Additionally, we determined how the interaction network for Cut11 is altered in canonical temperature-sensitive cut11-ts mutants. This library and screening approach is readily applicable to characterizing the interactomes of integral membrane proteins localizing to various subcellular compartments.
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19
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Jaspersen SL. Anatomy of the fungal microtubule organizing center, the spindle pole body. Curr Opin Struct Biol 2020; 66:22-31. [PMID: 33113389 DOI: 10.1016/j.sbi.2020.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/14/2020] [Accepted: 09/19/2020] [Indexed: 12/21/2022]
Abstract
The fungal kingdom is large and diverse, representing extremes of ecology, life cycles and morphology. At a cellular level, the diversity among fungi is particularly apparent at the spindle pole body (SPB). This nuclear envelope embedded structure, which is essential for microtubule nucleation, shows dramatically different morphologies between different fungi. However, despite phenotypic diversity, many SPB components are conserved, suggesting commonalities in structure, function and duplication. Here, I review the organization of the most well-studied SPBs and describe how advances in genomics, genetics and cell biology have accelerated knowledge of SPB architecture in other fungi, providing insights into microtubule nucleation and other processes conserved across eukaryotes.
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Affiliation(s)
- Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO 64110, United States; Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, United States.
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20
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Geymonat M, Peng Q, Guo Z, Yu Z, Unruh JR, Jaspersen SL, Segal M. Orderly assembly underpinning built-in asymmetry in the yeast centrosome duplication cycle requires cyclin-dependent kinase. eLife 2020; 9:59222. [PMID: 32851976 PMCID: PMC7470843 DOI: 10.7554/elife.59222] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/21/2020] [Indexed: 12/13/2022] Open
Abstract
Asymmetric astral microtubule organization drives the polarized orientation of the S. cerevisiae mitotic spindle and primes the invariant inheritance of the old spindle pole body (SPB, the yeast centrosome) by the bud. This model has anticipated analogous centrosome asymmetries featured in self-renewing stem cell divisions. We previously implicated Spc72, the cytoplasmic receptor for the gamma-tubulin nucleation complex, as the most upstream determinant linking SPB age, functional asymmetry and fate. Here we used structured illumination microscopy and biochemical analysis to explore the asymmetric landscape of nucleation sites inherently built into the spindle pathway and under the control of cyclin-dependent kinase (CDK). We show that CDK enforces Spc72 asymmetric docking by phosphorylating Nud1/centriolin. Furthermore, CDK-imposed order in the construction of the new SPB promotes the correct balance of nucleation sites between the nuclear and cytoplasmic faces of the SPB. Together these contributions by CDK inherently link correct SPB morphogenesis, age and fate.
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Affiliation(s)
- Marco Geymonat
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Qiuran Peng
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Zhiang Guo
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, United States
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, United States
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, United States.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, United States
| | - Marisa Segal
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
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21
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Ito D, Zitouni S, Jana SC, Duarte P, Surkont J, Carvalho-Santos Z, Pereira-Leal JB, Ferreira MG, Bettencourt-Dias M. Pericentrin-mediated SAS-6 recruitment promotes centriole assembly. eLife 2019; 8:41418. [PMID: 31182187 PMCID: PMC6559791 DOI: 10.7554/elife.41418] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 05/14/2019] [Indexed: 12/21/2022] Open
Abstract
The centrosome is composed of two centrioles surrounded by a microtubule-nucleating pericentriolar material (PCM). Although centrioles are known to regulate PCM assembly, it is less known whether and how the PCM contributes to centriole assembly. Here we investigate the interaction between centriole components and the PCM by taking advantage of fission yeast, which has a centriole-free, PCM-containing centrosome, the SPB. Surprisingly, we observed that several ectopically-expressed animal centriole components such as SAS-6 are recruited to the SPB. We revealed that a conserved PCM component, Pcp1/pericentrin, interacts with and recruits SAS-6. This interaction is conserved and important for centriole assembly, particularly its elongation. We further explored how yeasts kept this interaction even after centriole loss and showed that the conserved calmodulin-binding region of Pcp1/pericentrin is critical for SAS-6 interaction. Our work suggests that the PCM not only recruits and concentrates microtubule-nucleators, but also the centriole assembly machinery, promoting biogenesis close by.
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Affiliation(s)
- Daisuke Ito
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | | | | | - Paulo Duarte
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | | | | | - José B Pereira-Leal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Ophiomics, Precision Medicine, Lisboa, Portugal
| | - Miguel Godinho Ferreira
- Instituto Gulbenkian de Ciência, Oeiras, Portugal.,Institute for Research on Cancer and Aging of Nice (IRCAN), INSERM U1081 UMR7284 CNRS, Nice, France
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22
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Spindle assembly without spindle pole body insertion into the nuclear envelope in fission yeast meiosis. Chromosoma 2019; 128:267-277. [PMID: 31152193 DOI: 10.1007/s00412-019-00710-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 05/09/2019] [Accepted: 05/16/2019] [Indexed: 01/23/2023]
Abstract
Centrosomes represent the major microtubule organizing center (MTOC) in eukaryotic cells and are responsible for nucleation of the spindle, the vehicle of chromosome segregation. In human female meiosis, however, spindle assembly occurs in the absence of centrosomes or other MTOCs and microtubules are nucleated around chromosomes. In yeast, spindle formation in mitosis and meiosis depends on the activity of spindle pole bodies (SPBs), the functional equivalents of centrosomes; thus, SPBs and centrosomes use similar machineries to assemble spindles. Here, we develop a system to explore the molecular mechanisms supporting acentrosomal spindle formation using fission yeast meiosis as a model scenario. We achieve this situation by removing access of the SPBs to the nucleus after their duplication. Under these conditions, we observe self-assembly-based spindle formation in the nuclear environment, conferring an ability to segregate chromosomes independently of the SPBs. Our results open the possibility to utilize the experimental advantages of fission yeast for insights into the molecular basis of acentrosomal spindle formation in meiosis.
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23
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Chen J, Gardner JM, Yu Z, Smith SE, McKinney S, Slaughter BD, Unruh JR, Jaspersen SL. Yeast centrosome components form a noncanonical LINC complex at the nuclear envelope insertion site. J Cell Biol 2019; 218:1478-1490. [PMID: 30862629 PMCID: PMC6504903 DOI: 10.1083/jcb.201809045] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/17/2019] [Accepted: 02/19/2019] [Indexed: 01/23/2023] Open
Abstract
How the nuclear envelope is remodeled to facilitate insertion of large protein complexes is poorly understood. Chen et al. use superresolution imaging with bimolecular fluorescence complementation to show that a novel noncanonical linker of nucleoskeleton and cytoskeleton (LINC) complex forms at sites of nuclear envelope fenestration in yeast. Bipolar spindle formation in yeast requires insertion of centrosomes (known as spindle pole bodies [SPBs]) into fenestrated regions of the nuclear envelope (NE). Using structured illumination microscopy and bimolecular fluorescence complementation, we map protein distribution at SPB fenestrae and interrogate protein–protein interactions with high spatial resolution. We find that the Sad1-UNC-84 (SUN) protein Mps3 forms a ring-like structure around the SPB, similar to toroids seen for components of the SPB insertion network (SPIN). Mps3 and the SPIN component Mps2 (a Klarsicht-ANC-1-Syne-1 domain [KASH]–like protein) form a novel noncanonical linker of nucleoskeleton and cytoskeleton (LINC) complex that is connected in both luminal and extraluminal domains at the site of SPB insertion. The LINC complex also controls the distribution of a soluble SPIN component Bbp1. Taken together, our work shows that Mps3 is a fifth SPIN component and suggests both direct and indirect roles for the LINC complex in NE remodeling.
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Affiliation(s)
- Jingjing Chen
- Stowers Institute for Medical Research, Kansas City, MO
| | | | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, MO
| | - Sarah E Smith
- Stowers Institute for Medical Research, Kansas City, MO
| | - Sean McKinney
- Stowers Institute for Medical Research, Kansas City, MO
| | | | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO .,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS
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24
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Watanabe K, Takao D, Ito KK, Takahashi M, Kitagawa D. The Cep57-pericentrin module organizes PCM expansion and centriole engagement. Nat Commun 2019; 10:931. [PMID: 30804344 PMCID: PMC6389942 DOI: 10.1038/s41467-019-08862-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/31/2019] [Indexed: 02/07/2023] Open
Abstract
Centriole duplication occurs once per cell cycle to ensure robust formation of bipolar spindles and chromosome segregation. Each newly-formed daughter centriole remains connected to its mother centriole until late mitosis. The disengagement of the centriole pair is required for centriole duplication. However, the mechanisms underlying centriole engagement remain poorly understood. Here, we show that Cep57 is required for pericentriolar material (PCM) organization that regulates centriole engagement. Depletion of Cep57 causes PCM disorganization and precocious centriole disengagement during mitosis. The disengaged daughter centrioles acquire ectopic microtubule-organizing-center activity, which results in chromosome mis-segregation. Similar defects are observed in mosaic variegated aneuploidy syndrome patient cells with cep57 mutations. We also find that Cep57 binds to the well-conserved PACT domain of pericentrin. Microcephaly osteodysplastic primordial dwarfism disease pericentrin mutations impair the Cep57-pericentrin interaction and lead to PCM disorganization. Together, our work demonstrates that Cep57 provides a critical interface between the centriole core and PCM. Centriole disengagement occurs towards mitotic exit and involves cleavage of pericentrin, a component of the pericentriolar material. Here the authors show that depletion of the centrosomal protein Cep57 leads to precocious centriole disengagement, and that Cep57 binds pericentrin.
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Affiliation(s)
- Koki Watanabe
- Division of Centrosome Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.,Department of Genetics, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, 240-0193, Japan.,Department of Physiological Chemistry, Graduate school of Pharmaceutical Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
| | - Daisuke Takao
- Division of Centrosome Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.,Department of Physiological Chemistry, Graduate school of Pharmaceutical Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
| | - Kei K Ito
- Department of Physiological Chemistry, Graduate school of Pharmaceutical Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan
| | - Mikiko Takahashi
- Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Nakano, Tokyo, 164-8530, Japan
| | - Daiju Kitagawa
- Division of Centrosome Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan. .,Department of Genetics, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, 240-0193, Japan. .,Department of Physiological Chemistry, Graduate school of Pharmaceutical Sciences, The University of Tokyo, Bunkyo, Tokyo, 113-0033, Japan.
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25
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Combined expansion microscopy with structured illumination microscopy for analyzing protein complexes. Nat Protoc 2018; 13:1869-1895. [PMID: 30072723 DOI: 10.1038/s41596-018-0023-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/09/2018] [Indexed: 12/19/2022]
Abstract
Biologists have long been fascinated with the organization and function of intricate protein complexes. Therefore, techniques for precisely imaging protein complexes and the location of proteins within these complexes are critically important and often require multidisciplinary collaboration. A challenge in these explorations is the limited resolution of conventional light microscopy. However, a new microscopic technique has circumvented this resolution limit by making the biological sample larger, thus allowing for super-resolution of the enlarged structure. This 'expansion' is accomplished by embedding the sample in a hydrogel that, when exposed to water, uniformly expands. Here, we present a protocol that transforms thick expansion microscopy (ExM) hydrogels into sections that are physically expanded four times, creating samples that are compatible with the super-resolution technique structured illumination microscopy (SIM). This super-resolution ExM method (ExM-SIM) allows the analysis of the three-dimensional (3D) organization of multiprotein complexes at ~30-nm lateral (xy) resolution. This protocol details the steps necessary for analysis of protein localization using ExM-SIM, including antibody labeling, hydrogel preparation, protease digestion, post-digestion antibody labeling, hydrogel embedding with tissue-freezing medium (TFM), cryosectioning, expansion, image alignment, and particle averaging. We have used this approach for 3D mapping of in situ protein localization in the Drosophila synaptonemal complex (SC), but it can be readily adapted to study thick tissues such as brain and organs in various model systems. This procedure can be completed in 5 d.
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26
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Ito D, Bettencourt-Dias M. Centrosome Remodelling in Evolution. Cells 2018; 7:E71. [PMID: 29986477 PMCID: PMC6070874 DOI: 10.3390/cells7070071] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 06/27/2018] [Accepted: 07/04/2018] [Indexed: 11/16/2022] Open
Abstract
The centrosome is the major microtubule organizing centre (MTOC) in animal cells. The canonical centrosome is composed of two centrioles surrounded by a pericentriolar matrix (PCM). In contrast, yeasts and amoebozoa have lost centrioles and possess acentriolar centrosomes—called the spindle pole body (SPB) and the nucleus-associated body (NAB), respectively. Despite the difference in their structures, centriolar centrosomes and SPBs not only share components but also common biogenesis regulators. In this review, we focus on the SPB and speculate how its structures evolved from the ancestral centrosome. Phylogenetic distribution of molecular components suggests that yeasts gained specific SPB components upon loss of centrioles but maintained PCM components associated with the structure. It is possible that the PCM structure remained even after centrosome remodelling due to its indispensable function to nucleate microtubules. We propose that the yeast SPB has been formed by a step-wise process; (1) an SPB-like precursor structure appeared on the ancestral centriolar centrosome; (2) it interacted with the PCM and the nuclear envelope; and (3) it replaced the roles of centrioles. Acentriolar centrosomes should continue to be a great model to understand how centrosomes evolved and how centrosome biogenesis is regulated.
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Affiliation(s)
- Daisuke Ito
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal.
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27
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Duplication and Nuclear Envelope Insertion of the Yeast Microtubule Organizing Centre, the Spindle Pole Body. Cells 2018; 7:cells7050042. [PMID: 29748517 PMCID: PMC5981266 DOI: 10.3390/cells7050042] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 11/16/2022] Open
Abstract
The main microtubule organizing centre in the unicellular model organisms Saccharomyces cerevisiae and Schizosaccharomyces pompe is the spindle pole body (SPB). The SPB is a multilayer structure, which duplicates exactly once per cell cycle. Unlike higher eukaryotic cells, both yeast model organisms undergo mitosis without breakdown of the nuclear envelope (NE), a so-called closed mitosis. Therefore, in order to simultaneously nucleate nuclear and cytoplasmic MTs, it is vital to embed the SPB into the NE at least during mitosis, similarly to the nuclear pore complex (NPC). This review aims to embrace the current knowledge of the SPB duplication cycle with special emphasis on the critical step of the insertion of the new SPB into the NE.
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28
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Koonce MP, Tikhonenko I. Centrosome Positioning in Dictyostelium: Moving beyond Microtubule Tip Dynamics. Cells 2018; 7:E29. [PMID: 29649097 PMCID: PMC5946106 DOI: 10.3390/cells7040029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 12/29/2022] Open
Abstract
The variability in centrosome size, shape, and activity among different organisms provides an opportunity to understand both conserved and specialized actions of this intriguing organelle. Centrosomes in the model organism Dictyostelium sp. share some features with fungal systems and some with vertebrate cell lines and thus provide a particularly useful context to study their dynamics. We discuss two aspects, centrosome positioning in cells and their interactions with nuclei during division as a means to highlight evolutionary modifications to machinery that provide the most basic of cellular services.
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Affiliation(s)
- Michael P Koonce
- Division of Translational Medicine, New York State Department of Health, Wadsworth Center, Albany, NY 12201-0509, USA.
| | - Irina Tikhonenko
- Division of Translational Medicine, New York State Department of Health, Wadsworth Center, Albany, NY 12201-0509, USA.
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Komis G, Novák D, Ovečka M, Šamajová O, Šamaj J. Advances in Imaging Plant Cell Dynamics. PLANT PHYSIOLOGY 2018; 176:80-93. [PMID: 29167354 PMCID: PMC5761809 DOI: 10.1104/pp.17.00962] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/20/2017] [Indexed: 05/20/2023]
Abstract
Advanced bioimaging uncovers insights into subcellular structures of plants.
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Affiliation(s)
- George Komis
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, 783 71 Olomouc, Czech Republic
| | - Dominik Novák
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, 783 71 Olomouc, Czech Republic
| | - Miroslav Ovečka
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, 783 71 Olomouc, Czech Republic
| | - Olga Šamajová
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, 783 71 Olomouc, Czech Republic
| | - Jozef Šamaj
- Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, 783 71 Olomouc, Czech Republic
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30
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Unruh JR, Slaughter BD, Jaspersen SL. Functional Analysis of the Yeast LINC Complex Using Fluctuation Spectroscopy and Super-Resolution Imaging. Methods Mol Biol 2018; 1840:137-161. [PMID: 30141044 DOI: 10.1007/978-1-4939-8691-0_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The Saccharomyces cerevisiae and Schizosaccharomyces pombe genomes encode a single SUN domain-containing protein, Mps3 and Sad1, respectively. Both localize to the yeast centrosome (known as the spindle pole body, SPB) and are essential for bipolar spindle formation. In addition, Mps3 and Sad1 play roles in chromosome organization in both mitotic and meiotic cells that are independent of their SPB function. To dissect the function of Mps3 at the nuclear envelope (NE) and SPB, we employed cell imaging methods such as scanning fluorescence cross-correlation spectroscopy (SFCCS) and single particle averaging with structured illumination microscopy (SPA-SIM) to determine the strength, nature, and location of protein-protein interactions in vivo. We describe how these same techniques can also be used in fission yeast to analyze Sad1, providing evidence of their applicability to other NE proteins and systems.
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Affiliation(s)
- Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | | | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO, USA.
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.
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31
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Cavanaugh AM, Jaspersen SL. Big Lessons from Little Yeast: Budding and Fission Yeast Centrosome Structure, Duplication, and Function. Annu Rev Genet 2017; 51:361-383. [PMID: 28934593 DOI: 10.1146/annurev-genet-120116-024733] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Centrosomes are a functionally conserved feature of eukaryotic cells that play an important role in cell division. The conserved γ-tubulin complex organizes spindle and astral microtubules, which, in turn, separate replicated chromosomes accurately into daughter cells. Like DNA, centrosomes are duplicated once each cell cycle. Although in some cell types it is possible for cell division to occur in the absence of centrosomes, these divisions typically result in defects in chromosome number and stability. In single-celled organisms such as fungi, centrosomes [known as spindle pole bodies (SPBs)] are essential for cell division. SPBs also must be inserted into the membrane because fungi undergo a closed mitosis in which the nuclear envelope (NE) remains intact. This poorly understood process involves events similar or identical to those needed for de novo nuclear pore complex assembly. Here, we review how analysis of fungal SPBs has advanced our understanding of centrosomes and NE events.
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Affiliation(s)
- Ann M Cavanaugh
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA;
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA; .,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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