1
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KYOGOKU H, KITAJIMA TS. The large cytoplasmic volume of oocyte. J Reprod Dev 2023; 69:1-9. [PMID: 36436912 PMCID: PMC9939283 DOI: 10.1262/jrd.2022-101] [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] [Indexed: 11/26/2022] Open
Abstract
The study of the size of cells and organelles has a long history, dating back to the 1600s when cells were defined. In particular, various methods have elucidated the size of the nucleus and the mitotic spindle in several species. However, little research has been conducted on oocyte size and organelles in mammals, and many questions remain to be answered. The appropriate size is essential to cell function properly. Oocytes have a very large cytoplasm, which is more than 100 times larger than that of general somatic cells in mammals. In this review, we discuss how oocytes acquire an enormous cytoplasmic size and the adverse effects of a large cytoplasmic size on cellular functions.
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Affiliation(s)
- Hirohisa KYOGOKU
- Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan,Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Tomoya S KITAJIMA
- Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
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2
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Holzer E, Rumpf-Kienzl C, Falk S, Dammermann A. A modified TurboID approach identifies tissue-specific centriolar components in C. elegans. PLoS Genet 2022; 18:e1010150. [PMID: 35442950 PMCID: PMC9020716 DOI: 10.1371/journal.pgen.1010150] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/15/2022] [Indexed: 01/26/2023] Open
Abstract
Proximity-dependent labeling approaches such as BioID have been a great boon to studies of protein-protein interactions in the context of cytoskeletal structures such as centrosomes which are poorly amenable to traditional biochemical approaches like immunoprecipitation and tandem affinity purification. Yet, these methods have so far not been applied extensively to invertebrate experimental models such as C. elegans given the long labeling times required for the original promiscuous biotin ligase variant BirA*. Here, we show that the recently developed variant TurboID successfully probes the interactomes of both stably associated (SPD-5) and dynamically localized (PLK-1) centrosomal components. We further develop an indirect proximity labeling method employing a GFP nanobody-TurboID fusion, which allows the identification of protein interactors in a tissue-specific manner in the context of the whole animal. Critically, this approach utilizes available endogenous GFP fusions, avoiding the need to generate multiple additional strains for each target protein and the potential complications associated with overexpressing the protein from transgenes. Using this method, we identify homologs of two highly conserved centriolar components, Cep97 and BLD10/Cep135, which are present in various somatic tissues of the worm. Surprisingly, neither protein is expressed in early embryos, likely explaining why these proteins have escaped attention until now. Our work expands the experimental repertoire for C. elegans and opens the door for further studies of tissue-specific variation in centrosome architecture.
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Affiliation(s)
- Elisabeth Holzer
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | | | - Sebastian Falk
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
| | - Alexander Dammermann
- Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Vienna, Austria
- * E-mail:
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3
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Sugioka K. Symmetry-breaking of animal cytokinesis. Semin Cell Dev Biol 2021; 127:100-109. [PMID: 34955355 DOI: 10.1016/j.semcdb.2021.12.008] [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] [Received: 07/30/2021] [Revised: 12/05/2021] [Accepted: 12/16/2021] [Indexed: 12/24/2022]
Abstract
Cytokinesis is a mechanism that separates dividing cells via constriction of a supramolecular structure, the contractile ring. In animal cells, three modes of symmetry-breaking of cytokinesis result in unilateral cytokinesis, asymmetric cell division, and oriented cell division. Each mode of cytokinesis plays a significant role in tissue patterning and morphogenesis by the mechanisms that control the orientation and position of the contractile ring relative to the body axis. Despite its significance, the mechanisms involved in the symmetry-breaking of cytokinesis remain unclear in many cell types. Classical embryologists have identified that the geometric relationship between the mitotic spindle and cell cortex induces cytokinesis asymmetry; however, emerging evidence suggests that a concerted flow of compressional cell-cortex materials (cortical flow) is a spindle-independent driving force in spatial cytokinesis control. This review provides an overview of both classical and emerging mechanisms of cytokinesis asymmetry and their roles in animal development.
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Affiliation(s)
- Kenji Sugioka
- Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T1Z3, Canada; Department of Zoology, The University of British Columbia, Vancouver, BC V6T1Z3, Canada.
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4
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Mani N, Jiang S, Neary AE, Wijeratne SS, Subramanian R. Differential regulation of single microtubules and bundles by a three-protein module. Nat Chem Biol 2021; 17:964-974. [PMID: 34083810 PMCID: PMC8387365 DOI: 10.1038/s41589-021-00800-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 04/19/2021] [Indexed: 12/15/2022]
Abstract
A remarkable feature of the microtubule cytoskeleton is co-existence of sub-populations having different dynamic properties. A prominent example is the anaphase spindle, where stable antiparallel bundles exist alongside dynamic microtubules and provide spatial cues for cytokinesis. How are dynamics of spatially proximal arrays differentially regulated? We reconstitute a minimal system of three midzone proteins: microtubule-crosslinker PRC1, and its interactors CLASP1 and Kif4A, proteins that promote and suppress microtubule elongation, respectively. We find their collective activity promotes elongation of single microtubules, while simultaneously stalling polymerization of crosslinked bundles. This differentiation arises from (i) Strong rescue activity of CLASP1, which overcomes weaker effects of Kif4A on single microtubules, (ii) Lower microtubule and PRC1-binding affinity of CLASP1, which permit dominance of Kif4A at overlaps. In addition to canonical mechanisms where antagonistic regulators set microtubule lengths, our findings illuminate design principles by which collective regulator activity creates microenvironments of arrays with distinct dynamic properties.
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Affiliation(s)
- Nandini Mani
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Shuo Jiang
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Alex E Neary
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA
| | - Sithara S Wijeratne
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Radhika Subramanian
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA. .,Department of Genetics, Harvard Medical School, Boston, MA, USA.
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5
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Bouvrais H, Chesneau L, Le Cunff Y, Fairbrass D, Soler N, Pastezeur S, Pécot T, Kervrann C, Pécréaux J. The coordination of spindle-positioning forces during the asymmetric division of the Caenorhabditis elegans zygote. EMBO Rep 2021; 22:e50770. [PMID: 33900015 DOI: 10.15252/embr.202050770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 02/22/2021] [Accepted: 03/03/2021] [Indexed: 12/28/2022] Open
Abstract
In Caenorhabditis elegans zygote, astral microtubules generate forces essential to position the mitotic spindle, by pushing against and pulling from the cortex. Measuring microtubule dynamics there, we revealed the presence of two populations, corresponding to pulling and pushing events. It offers a unique opportunity to study, under physiological conditions, the variations of both spindle-positioning forces along space and time. We propose a threefold control of pulling force, by polarity, spindle position and mitotic progression. We showed that the sole anteroposterior asymmetry in dynein on-rate, encoding pulling force imbalance, is sufficient to cause posterior spindle displacement. The positional regulation, reflecting the number of microtubule contacts in the posterior-most region, reinforces this imbalance only in late anaphase. Furthermore, we exhibited the first direct proof that dynein processivity increases along mitosis. It reflects the temporal control of pulling forces, which strengthens at anaphase onset following mitotic progression and independently from chromatid separation. In contrast, the pushing force remains constant and symmetric and contributes to maintaining the spindle at the cell centre during metaphase.
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Affiliation(s)
| | | | - Yann Le Cunff
- CNRS, IGDR - UMR 6290, University of Rennes, Rennes, France
| | | | - Nina Soler
- CNRS, IGDR - UMR 6290, University of Rennes, Rennes, France
| | | | - Thierry Pécot
- INRIA, Centre Rennes - Bretagne Atlantique, Rennes, France
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6
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Shoda T, Yamazoe K, Tanaka Y, Asano Y, Inoue YH. Orbit/CLASP determines centriole length by antagonising Klp10A in Drosophila spermatocytes. J Cell Sci 2021; 134:jcs251231. [PMID: 33674447 PMCID: PMC8015252 DOI: 10.1242/jcs.251231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 02/10/2021] [Indexed: 12/17/2022] Open
Abstract
After centrosome duplication, centrioles elongate before M phase. To identify genes required for this process and to understand the regulatory mechanism, we investigated the centrioles in Drosophila premeiotic spermatocytes expressing fluorescently tagged centriolar proteins. We demonstrated that an essential microtubule polymerisation factor, Orbit (the Drosophila CLASP orthologue, encoded by chb), accumulated at the distal end of centrioles and was required for the elongation. Conversely, a microtubule-severing factor, Klp10A, shortened the centrioles. Genetic analyses revealed that these two proteins functioned antagonistically to determine centriole length. Furthermore, Cp110 in the distal tip complex was closely associated with the factors involved in centriolar dynamics at the distal end. We observed loss of centriole integrity, including fragmentation of centrioles and earlier separation of the centriole pairs, in Cp110-null mutant cells either overexpressing Orbit or depleted of Klp10A Excess centriole elongation in the absence of the distal tip complex resulted in the loss of centriole integrity, leading to the formation of multipolar spindle microtubules emanating from centriole fragments, even when they were unpaired. Our findings contribute to understanding the mechanism of centriole integrity, disruption of which leads to chromosome instability in cancer cells.
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Affiliation(s)
- Tsuyoshi Shoda
- Department of Insect Biomedical Research, Centre for Advanced Insect Research Promotion, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Kanta Yamazoe
- Department of Insect Biomedical Research, Centre for Advanced Insect Research Promotion, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Yuri Tanaka
- Department of Insect Biomedical Research, Centre for Advanced Insect Research Promotion, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Yuki Asano
- Department of Insect Biomedical Research, Centre for Advanced Insect Research Promotion, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Yoshihiro H Inoue
- Department of Insect Biomedical Research, Centre for Advanced Insect Research Promotion, Kyoto Institute of Technology, Kyoto 606-8585, Japan
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7
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Schlientz AJ, Bowerman B. C. elegans CLASP/CLS-2 negatively regulates membrane ingression throughout the oocyte cortex and is required for polar body extrusion. PLoS Genet 2020; 16:e1008751. [PMID: 33027250 PMCID: PMC7571700 DOI: 10.1371/journal.pgen.1008751] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 10/19/2020] [Accepted: 08/10/2020] [Indexed: 11/26/2022] Open
Abstract
The requirements for oocyte meiotic cytokinesis during polar body extrusion are not well understood. In particular, the relationship between the oocyte meiotic spindle and polar body contractile ring dynamics remains largely unknown. We have used live cell imaging and spindle assembly defective mutants lacking the function of CLASP/CLS-2, kinesin-12/KLP-18, or katanin/MEI-1 to investigate the relationship between meiotic spindle structure and polar body extrusion in C. elegans oocytes. We show that spindle bipolarity and chromosome segregation are not required for polar body contractile ring formation and chromosome extrusion in klp-18 mutants. In contrast, oocytes with similarly severe spindle assembly defects due to loss of CLS-2 or MEI-1 have penetrant and distinct polar body extrusion defects: CLS-2 is required early for contractile ring assembly or stability, while MEI-1 is required later for contractile ring constriction. We also show that CLS-2 both negatively regulates membrane ingression throughout the oocyte cortex during meiosis I, and influences the dynamics of the central spindle-associated proteins Aurora B/AIR-2 and MgcRacGAP/CYK-4. We suggest that proper regulation by CLS-2 of both oocyte cortical stiffness and central spindle protein dynamics may influence contractile ring assembly during polar body extrusion in C. elegans oocytes.
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Affiliation(s)
- Aleesa J. Schlientz
- Institute of Molecular Biology, University of Oregon, Eugene, OR, United States of America
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR, United States of America
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8
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Guilloux G, Gibeaux R. Mechanisms of spindle assembly and size control. Biol Cell 2020; 112:369-382. [PMID: 32762076 DOI: 10.1111/boc.202000065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/03/2020] [Accepted: 08/03/2020] [Indexed: 01/09/2023]
Abstract
The spindle is crucial for cell division by allowing the faithful segregation of replicated chromosomes to daughter cells. Proper segregation is ensured only if microtubules (MTs) and hundreds of other associated factors interact to assemble this complex structure with the appropriate architecture and size. In this review, we describe the latest view of spindle organisation as well as the molecular gradients and mechanisms underlying MT nucleation and spindle assembly. We then discuss the overlapping physical and molecular constraints that dictate spindle morphology, concluding with a focus on spindle size regulation.
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Affiliation(s)
- Gabriel Guilloux
- Univ Rennes, CNRS, IGDR [(Institute of Genetics and Development of Rennes)] - UMR 6290, F-35000 Rennes, France
| | - Romain Gibeaux
- Univ Rennes, CNRS, IGDR [(Institute of Genetics and Development of Rennes)] - UMR 6290, F-35000 Rennes, France
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9
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Baris Atakan H, Alkanat T, Cornaglia M, Trouillon R, Gijs MAM. Automated phenotyping of Caenorhabditis elegans embryos with a high-throughput-screening microfluidic platform. MICROSYSTEMS & NANOENGINEERING 2020; 6:24. [PMID: 34567639 PMCID: PMC8433184 DOI: 10.1038/s41378-020-0132-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/30/2019] [Accepted: 12/16/2019] [Indexed: 05/25/2023]
Abstract
The nematode Caenorhabditis elegans has been extensively used as a model multicellular organism to study the influence of osmotic stress conditions and the toxicity of chemical compounds on developmental and motility-associated phenotypes. However, the several-day culture of nematodes needed for such studies has caused researchers to explore alternatives. In particular, C. elegans embryos, due to their shorter developmental time and immobile nature, could be exploited for this purpose, although usually their harvesting and handling is tedious. Here, we present a multiplexed, high-throughput and automated embryo phenotyping microfluidic approach to observe C. elegans embryogenesis after the application of different chemical compounds. After performing experiments with up to 800 embryos per chip and up to 12 h of time-lapsed imaging per embryo, the individual phenotypic developmental data were collected and analyzed through machine learning and image processing approaches. Our proof-of-concept platform indicates developmental lag and the induction of mitochondrial stress in embryos exposed to high doses (200 mM) of glucose and NaCl, while small doses of sucrose and glucose were shown to accelerate development. Overall, our new technique has potential for use in large-scale developmental biology studies and opens new avenues for very rapid high-throughput and high-content screening using C. elegans embryos.
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Affiliation(s)
- Huseyin Baris Atakan
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Tunc Alkanat
- Department of Electrical Engineering, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
| | - Matteo Cornaglia
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Raphaël Trouillon
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Martin A. M. Gijs
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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10
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Fabig G, Kiewisz R, Lindow N, Powers JA, Cota V, Quintanilla LJ, Brugués J, Prohaska S, Chu DS, Müller-Reichert T. Male meiotic spindle features that efficiently segregate paired and lagging chromosomes. eLife 2020; 9:50988. [PMID: 32149606 PMCID: PMC7101234 DOI: 10.7554/elife.50988] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 03/08/2020] [Indexed: 01/25/2023] Open
Abstract
Chromosome segregation during male meiosis is tailored to rapidly generate multitudes of sperm. Little is known about mechanisms that efficiently partition chromosomes to produce sperm. Using live imaging and tomographic reconstructions of spermatocyte meiotic spindles in Caenorhabditis elegans, we find the lagging X chromosome, a distinctive feature of anaphase I in C. elegans males, is due to lack of chromosome pairing. The unpaired chromosome remains tethered to centrosomes by lengthening kinetochore microtubules, which are under tension, suggesting that a ‘tug of war’ reliably resolves lagging. We find spermatocytes exhibit simultaneous pole-to-chromosome shortening (anaphase A) and pole-to-pole elongation (anaphase B). Electron tomography unexpectedly revealed spermatocyte anaphase A does not stem solely from kinetochore microtubule shortening. Instead, movement of autosomes is largely driven by distance change between chromosomes, microtubules, and centrosomes upon tension release during anaphase. Overall, we define novel features that segregate both lagging and paired chromosomes for optimal sperm production.
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Affiliation(s)
- Gunar Fabig
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Robert Kiewisz
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | | | - James A Powers
- Light Microscopy Imaging Center, Indiana University, Bloomington, United States
| | - Vanessa Cota
- Department of Biology, San Francisco State University, San Francisco, United States
| | - Luis J Quintanilla
- Department of Biology, San Francisco State University, San Francisco, United States
| | - Jan Brugués
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Centre for Systems Biology Dresden, Dresden, Germany
| | | | - Diana S Chu
- Department of Biology, San Francisco State University, San Francisco, United States
| | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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11
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Ebina H, Ji L, Sato M. CLASP promotes microtubule bundling in metaphase spindle independently of Ase1/PRC1 in fission yeast. Biol Open 2019; 8:bio.045716. [PMID: 31615768 PMCID: PMC6826280 DOI: 10.1242/bio.045716] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Microtubules in the mitotic spindle are organised by microtubule-associated proteins. In the late stage of mitosis, spindle microtubules are robustly organised through bundling by the antiparallel microtubule bundler Ase1/PRC1. In early mitosis, however, it is not well characterised as to whether spindle microtubules are actively bundled, as Ase1 does not particularly localise to the spindle at that stage. Here we show that the conserved microtubule-associated protein CLASP (fission yeast Peg1/Cls1) facilitates bundling of spindle microtubules in early mitosis. The peg1 mutant displayed a fragile spindle with unbundled microtubules, which eventually resulted in collapse of the metaphase spindle and abnormal segregation of chromosomes. Peg1 is known to be recruited to the spindle by Ase1 to stabilise antiparallel microtubules in late mitosis. However, we demonstrate that the function of Peg1 in early mitosis does not rely on Ase1. The unbundled spindle phenotype of the peg1 mutant was not seen in the ase1 mutant, and Peg1 preferentially localised to the spindle even in early mitosis unlike Ase1. Moreover, artificial overexpression of Ase1 in the peg1 mutant partially suppressed unbundled microtubules. We thus conclude that Peg1 bundles microtubules in early mitosis, in a distinct manner from its conventional Ase1-dependent functions in other cell cycle stages.
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Affiliation(s)
- Hirohisa Ebina
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering Waseda Research Institute for Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Liang Ji
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering Waseda Research Institute for Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan.,Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masamitsu Sato
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering Waseda Research Institute for Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan .,Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Institute for Medical-Oriented Structural Biology Waseda Research Institute for Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan.,Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
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12
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Pelisch F, Bel Borja L, Jaffray EG, Hay RT. Sumoylation regulates protein dynamics during meiotic chromosome segregation in C. elegans oocytes. J Cell Sci 2019; 132:jcs232330. [PMID: 31243051 PMCID: PMC6679583 DOI: 10.1242/jcs.232330] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/14/2019] [Indexed: 12/30/2022] Open
Abstract
Oocyte meiotic spindles in most species lack centrosomes and the mechanisms that underlie faithful chromosome segregation in acentrosomal meiotic spindles are not well understood. In C. elegans oocytes, spindle microtubules exert a poleward force on chromosomes that is dependent on the microtubule-stabilising protein CLS-2, the orthologue of the mammalian CLASP proteins. The checkpoint kinase BUB-1 and CLS-2 localise in the central spindle and display a dynamic localisation pattern throughout anaphase, but the signals regulating their anaphase-specific localisation remains unknown. We have shown previously that SUMO regulates BUB-1 localisation during metaphase I. Here, we found that SUMO modification of BUB-1 is regulated by the SUMO E3 ligase GEI-17 and the SUMO protease ULP-1. SUMO and GEI-17 are required for BUB-1 localisation between segregating chromosomes during early anaphase I. We also show that CLS-2 is subject to SUMO-mediated regulation; CLS-2 precociously localises in the midbivalent when either SUMO or GEI-17 are depleted. Overall, we provide evidence for a novel, SUMO-mediated control of protein dynamics during early anaphase I in oocytes.
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Affiliation(s)
- Federico Pelisch
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Laura Bel Borja
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Ellis G Jaffray
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Ronald T Hay
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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13
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Bouvrais H, Chesneau L, Pastezeur S, Fairbrass D, Delattre M, Pécréaux J. Microtubule Feedback and LET-99-Dependent Control of Pulling Forces Ensure Robust Spindle Position. Biophys J 2018; 115:2189-2205. [PMID: 30447992 PMCID: PMC6289040 DOI: 10.1016/j.bpj.2018.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 10/03/2018] [Accepted: 10/09/2018] [Indexed: 11/26/2022] Open
Abstract
During asymmetric division of the Caenorhabditis elegans zygote, to properly distribute cell fate determinants, the mitotic spindle is asymmetrically localized by a combination of centering and cortical-pulling microtubule-mediated forces, the dynamics of the latter being regulated by mitotic progression. Here, we show a, to our knowledge, novel and additional regulation of these forces by spindle position itself. For that, we observed the onset of transverse spindle oscillations, which reflects the burst of anaphase pulling forces. After delaying anaphase onset, we found that the position at which the spindle starts to oscillate was unchanged compared to control embryos and uncorrelated to anaphase onset. In mapping the cortical microtubule dynamics, we measured a steep increase in microtubule contact density after the posterior centrosome reached the critical position of 70% of embryo length, strongly suggesting the presence of a positional switch for spindle oscillations. Expanding a previous model based on a force-generator temporal control, we implemented this positional switch and observed that the large increase in microtubule density accounted for the pulling force burst. Thus, we propose that the spindle position influences the cortical availability of microtubules on which the active force generators, controlled by cell cycle progression, can pull. Importantly, we found that this positional control relies on the polarity-dependent LET-99 cortical band, the boundary of which could be probed by microtubules. This dual positional and temporal control well accounted for our observation that the oscillation onset position resists changes in cellular geometry and moderate variations in the active force generator number. Finally, our model suggests that spindle position at mitosis end is more sensitive to the polarity factor LET-99, which restricts the region of active force generators to a posterior-most region, than to microtubule number or force generator number/activity. Overall, we show that robustness in spindle positioning originates in cell mechanics rather than biochemical networks.
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Affiliation(s)
| | | | | | | | - Marie Delattre
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, Laboratory of Biology and Modelling of the Cell, Lyon University, Lyon, France
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14
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Lacroix B, Letort G, Pitayu L, Sallé J, Stefanutti M, Maton G, Ladouceur AM, Canman JC, Maddox PS, Maddox AS, Minc N, Nédélec F, Dumont J. Microtubule Dynamics Scale with Cell Size to Set Spindle Length and Assembly Timing. Dev Cell 2018; 45:496-511.e6. [PMID: 29787710 DOI: 10.1016/j.devcel.2018.04.022] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/22/2018] [Accepted: 04/24/2018] [Indexed: 12/22/2022]
Abstract
Successive cell divisions during embryonic cleavage create increasingly smaller cells, so intracellular structures must adapt accordingly. Mitotic spindle size correlates with cell size, but the mechanisms for this scaling remain unclear. Using live cell imaging, we analyzed spindle scaling during embryo cleavage in the nematode Caenorhabditis elegans and sea urchin Paracentrotus lividus. We reveal a common scaling mechanism, where the growth rate of spindle microtubules scales with cell volume, which explains spindle shortening. Spindle assembly timing is, however, constant throughout successive divisions. Analyses in silico suggest that controlling the microtubule growth rate is sufficient to scale spindle length and maintain a constant assembly timing. We tested our in silico predictions to demonstrate that modulating cell volume or microtubule growth rate in vivo induces a proportional spindle size change. Our results suggest that scalability of the microtubule growth rate when cell size varies adapts spindle length to cell volume.
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Affiliation(s)
- Benjamin Lacroix
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France.
| | - Gaëlle Letort
- Institut Curie, Mines Paris Tech, Inserm, U900, PSL Research University, 75005 Paris, France
| | - Laras Pitayu
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Jérémy Sallé
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Marine Stefanutti
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - Gilliane Maton
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | | | - Julie C Canman
- Columbia University Medical Center, Department of Pathology and Cell Biology, New York, NY 10032, USA
| | - Paul S Maddox
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Amy S Maddox
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Nicolas Minc
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France
| | - François Nédélec
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Julien Dumont
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, 75205 Paris, France.
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15
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Munoz NR, Black CJ, Young ET, Chu DS. New alleles of C. elegans gene cls-2 (R107.6), called xc3, xc4, and xc5. MICROPUBLICATION BIOLOGY 2017; 2017:10.17912/W2RQ2X. [PMID: 32550356 PMCID: PMC7255875 DOI: 10.17912/w2rq2x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nicholas R. Munoz
- Department of Biology, San Francisco State University, San Francisco, California 94132, USA
| | - Christopher J. Black
- Department of Biology, San Francisco State University, San Francisco, California 94132, USA
| | - Ethan T. Young
- Department of Biology, San Francisco State University, San Francisco, California 94132, USA
| | - Diana S. Chu
- Department of Biology, San Francisco State University, San Francisco, California 94132, USA,
Correspondence to: Diana S. Chu ()
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16
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Kinetochore-microtubule interactions in chromosome segregation: lessons from yeast and mammalian cells. Biochem J 2017; 474:3559-3577. [PMID: 29046344 DOI: 10.1042/bcj20170518] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/24/2017] [Accepted: 09/11/2017] [Indexed: 02/06/2023]
Abstract
Chromosome congression and segregation require robust yet dynamic attachment of the kinetochore with the spindle microtubules. Force generated at the kinetochore-microtubule interface plays a vital role to drive the attachment, as it is required to move chromosomes and to provide signal to sense correct attachments. To understand the mechanisms underlying these processes, it is critical to describe how the force is generated and how the molecules at the kinetochore-microtubule interface are organized and assembled to withstand the force and respond to it. Research in the past few years or so has revealed interesting insights into the structural organization and architecture of kinetochore proteins that couple kinetochore attachment to the spindle microtubules. Interestingly, despite diversities in the molecular players and their modes of action, there appears to be architectural similarity of the kinetochore-coupling machines in lower to higher eukaryotes. The present review focuses on the most recent advances in understanding of the molecular and structural aspects of kinetochore-microtubule interaction based on the studies in yeast and vertebrate cells.
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17
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Trieu TA, Navarro-Mendoza MI, Pérez-Arques C, Sanchis M, Capilla J, Navarro-Rodriguez P, Lopez-Fernandez L, Torres-Martínez S, Garre V, Ruiz-Vázquez RM, Nicolás FE. RNAi-Based Functional Genomics Identifies New Virulence Determinants in Mucormycosis. PLoS Pathog 2017; 13:e1006150. [PMID: 28107502 PMCID: PMC5287474 DOI: 10.1371/journal.ppat.1006150] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 02/01/2017] [Accepted: 12/22/2016] [Indexed: 01/17/2023] Open
Abstract
Mucorales are an emerging group of human pathogens that are responsible for the lethal disease mucormycosis. Unfortunately, functional studies on the genetic factors behind the virulence of these organisms are hampered by their limited genetic tractability, since they are reluctant to classical genetic tools like transposable elements or gene mapping. Here, we describe an RNAi-based functional genomic platform that allows the identification of new virulence factors through a forward genetic approach firstly described in Mucorales. This platform contains a whole-genome collection of Mucor circinelloides silenced transformants that presented a broad assortment of phenotypes related to the main physiological processes in fungi, including virulence, hyphae morphology, mycelial and yeast growth, carotenogenesis and asexual sporulation. Selection of transformants with reduced virulence allowed the identification of mcplD, which encodes a Phospholipase D, and mcmyo5, encoding a probably essential cargo transporter of the Myosin V family, as required for a fully virulent phenotype of M. circinelloides. Knock-out mutants for those genes showed reduced virulence in both Galleria mellonella and Mus musculus models, probably due to a delayed germination and polarized growth within macrophages. This study provides a robust approach to study virulence in Mucorales and as a proof of concept identified new virulence determinants in M. circinelloides that could represent promising targets for future antifungal therapies. Mucormycosis is an infectious disease caused by organisms of the order Mucorales. It is a lethal infection that is raising the alarm in the medical and scientific community due to its high mortality rates, unusual antifungal drug resistance and its emerging character. Among the reasons explaining the nescience about this disease is the lack of knowledge on the biology of the organisms that cause mucormycosis, which is encouraged by the reluctance of these species to genetic studies. In this work, we have developed an RNAi-based functional genomic platform to study virulence in Mucorales. It is a powerful tool available for the scientific community that will contribute to solve the reluctance of Mucorales to genetic studies and will help to understand the genetic basis of virulence in these organisms. Secondly, and as a proof of concept, we have used this genetic tool to identify two new virulence determinants in Mucor circinelloides. Lack of function of these determinants delays germination and growth of spores, conceding time to macrophages for the inactivation of the pathogen. The two genes identified, mcplD and mcmyo5, represent promising targets for future development of new antifungal therapies against mucormycosis.
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Affiliation(s)
- Trung Anh Trieu
- Departmento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Spain
| | | | - Carlos Pérez-Arques
- Departmento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Spain
| | - Marta Sanchis
- Unidad de Microbiología, Universitat Rovira i Virgili, IISPV, Tarragona, Spain
| | - Javier Capilla
- Unidad de Microbiología, Universitat Rovira i Virgili, IISPV, Tarragona, Spain
| | | | | | | | - Victoriano Garre
- Departmento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Spain
| | | | - Francisco E. Nicolás
- Departmento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Spain
- * E-mail:
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18
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Zhao J, Xin H, Cao L, Huang X, Shi C, Zhao P, Fu Y, Sun MX. NtDRP is necessary for accurate zygotic division orientation and differentiation of basal cell lineage toward suspensor formation. THE NEW PHYTOLOGIST 2016; 212:598-612. [PMID: 27348863 DOI: 10.1111/nph.14060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 05/14/2016] [Indexed: 05/08/2023]
Abstract
Plant embryogenesis begins with an asymmetric division of the zygote, producing apical and basal cells with distinct cell fates. The asymmetric zygote division is thought to be critical for embryo pattern formation; however, the molecular mechanisms regulating this process, especially maintaining the accurate position and proper orientation of cell division plane, remain poorly understood. Here, we report that a dynamin-related protein in Nicotiana tabacum, NtDRP, plays a critical role in maintaining orientation of zygotic division plane. Down-regulation of NtDRP caused zygotic cell division to occur in different, incorrect orientations and resulted in disruption of suspensor formation, and even development of twin embryos. The basal cell lineage totally integrated with the apical cell lineage into an embryo-like structure, suggesting that NtDRP is essential to accurate zygotic division orientation and differentiation of basal cell lineage toward suspensor formation. We also reveal that NtDRP plays its role by modulating microtubule spatial organization and spindle orientation during early embryogenesis. Thus, we revealed that NtDRP is involved in orientation of the asymmetric zygotic division and differentiation of distinct suspensor and embryo domains, as well as subsequent embryo pattern formation.
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Affiliation(s)
- Jing Zhao
- Department of Cell and Developmental Biology, College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Haiping Xin
- Department of Cell and Developmental Biology, College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, 430074, China
| | - Lingyan Cao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiaorong Huang
- Department of Cell and Developmental Biology, College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Ce Shi
- Department of Cell and Developmental Biology, College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Peng Zhao
- Department of Cell and Developmental Biology, College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Ying Fu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Meng-Xiang Sun
- Department of Cell and Developmental Biology, College of Life Science, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China.
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19
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Hui TH, Zheng F, Lin Y, Fu C. The linear and rotational motions of the fission yeast nucleus are governed by the stochastic dynamics of spatially distributed microtubules. J Biomech 2016; 49:1034-1041. [DOI: 10.1016/j.jbiomech.2016.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 01/22/2016] [Accepted: 02/07/2016] [Indexed: 12/01/2022]
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20
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Mishima M. Centralspindlin in Rappaport’s cleavage signaling. Semin Cell Dev Biol 2016; 53:45-56. [DOI: 10.1016/j.semcdb.2016.03.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 03/02/2016] [Indexed: 02/07/2023]
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21
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Cytoplasmic Determination of Meiotic Spindle Size Revealed by a Unique Inter-Species Germinal Vesicle Transfer Model. Sci Rep 2016; 6:19827. [PMID: 26813698 PMCID: PMC4728387 DOI: 10.1038/srep19827] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 12/07/2015] [Indexed: 11/08/2022] Open
Abstract
Spindle sizes are different in diverse species and cell types. In frogs, the meiotic spindle size is positively correlated with the egg cell volume. Across species, relatively small mouse oocytes (70–80 μm) have a relatively large spindle while larger pig oocytes (about 120 μm) have a considerably smaller spindle. In this study we investigated whether species-specific oocyte spindle size was determined by cytoplasmic or nuclear factors. By exchanging the germinal vesicle between mouse and pig oocytes, we obtained two kinds of reconstructed oocytes: one with mouse ooplasm and pig GV (mCy-pGV oocyte), and the other with pig ooplasm and mouse GV (pCy-mGV oocyte). We show that the MII spindle size of the mCy-pGV oocyte is similar to that of the mouse meiotic spindle and significantly larger than that of the pig meiotic spindle. The timing of oocyte maturation also followed that of the species from which the oocyte cytoplasm arose, although some impact of the origin of the GV was observed. These data suggest that spindle size and the timing of meiotic progression are governed by cytoplasmic components rather than cytoplasmic volume and GV materials.
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22
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Nahaboo W, Zouak M, Askjaer P, Delattre M. Chromatids segregate without centrosomes during Caenorhabditis elegans mitosis in a Ran- and CLASP-dependent manner. Mol Biol Cell 2015; 26:2020-9. [PMID: 25833711 PMCID: PMC4472013 DOI: 10.1091/mbc.e14-12-1577] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/20/2015] [Indexed: 01/23/2023] Open
Abstract
Laser ablation of centrosomes in one-cell Caenorhabditis elegans embryos shows that chromatids can segregate independently of centrosomes and also independently of the activity of kinetochore microtubules during mitosis. CLASP and RanGTP are required to generate this centrosome-independent force, whereas SPD-1 and BMK-1 act as brakes to oppose it. During mitosis, chromosomes are connected to a microtubule-based spindle. Current models propose that displacement of the spindle poles and/or the activity of kinetochore microtubules generate mechanical forces that segregate sister chromatids. Using laser destruction of the centrosomes during Caenorhabditis elegans mitosis, we show that neither of these mechanisms is necessary to achieve proper chromatid segregation. Our results strongly suggest that an outward force generated by the spindle midzone, independently of centrosomes, is sufficient to segregate chromosomes in mitotic cells. Using mutant and RNAi analysis, we show that the microtubule-bundling protein SPD-1/MAP-65 and BMK-1/kinesin-5 act as a brake opposing the force generated by the spindle midzone. Conversely, we identify a novel role for two microtubule-growth and nucleation agents, Ran and CLASP, in the establishment of the centrosome-independent force during anaphase. Their involvement raises the interesting possibility that microtubule polymerization of midzone microtubules is continuously required to sustain chromosome segregation during mitosis.
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Affiliation(s)
- Wallis Nahaboo
- Laboratory of Molecular Biology of the Cell, University of Lyon 1, CNRS UMR5239, Ecole Normale Supérieure de Lyon, 69007 Lyon, France
| | - Melissa Zouak
- Laboratory of Molecular Biology of the Cell, University of Lyon 1, CNRS UMR5239, Ecole Normale Supérieure de Lyon, 69007 Lyon, France
| | - Peter Askjaer
- Andalusian Centre for Developmental Biology, CSIC-Junta de Andalucia, Universidad Pablo de Olavide, Carretera de Utrera, 41012 Seville, Spain
| | - Marie Delattre
- Laboratory of Molecular Biology of the Cell, University of Lyon 1, CNRS UMR5239, Ecole Normale Supérieure de Lyon, 69007 Lyon, France
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23
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Ohta S, Wood L, Toramoto I, Yagyu KI, Fukagawa T, Earnshaw WC. CENP-32 is required to maintain centrosomal dominance in bipolar spindle assembly. Mol Biol Cell 2015; 26:1225-37. [PMID: 25657325 PMCID: PMC4454171 DOI: 10.1091/mbc.e14-09-1366] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
CENP-32 depletion releases centrosomes from spindles after initiating spindle assembly. The free centrosomes do not interfere with the structure or function of the bipolar anastral spindle. The asters appear to be able to interact with the surface of the spindle but are unable to incorporate into it. Centrosomes nucleate spindle formation, direct spindle pole positioning, and are important for proper chromosome segregation during mitosis in most animal cells. We previously reported that centromere protein 32 (CENP-32) is required for centrosome association with spindle poles during metaphase. In this study, we show that CENP-32 depletion seems to release centrosomes from bipolar spindles whose assembly they had previously initiated. Remarkably, the resulting anastral spindles function normally, aligning the chromosomes to a metaphase plate and entering anaphase without detectable interference from the free centrosomes, which appear to behave as free asters in these cells. The free asters, which contain reduced but significant levels of CDK5RAP2, show weak interactions with spindle microtubules but do not seem to make productive attachments to kinetochores. Thus CENP-32 appears to be required for centrosomes to integrate into a fully functional spindle that not only nucleates astral microtubules, but also is able to nucleate and bind to kinetochore and central spindle microtubules. Additional data suggest that NuMA tethers microtubules at the anastral spindle poles and that augmin is required for centrosome detachment after CENP-32 depletion, possibly due to an imbalance of forces within the spindle.
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Affiliation(s)
- Shinya Ohta
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom Medical School, Kochi University, Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan
| | - Laura Wood
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Iyo Toramoto
- Medical School, Kochi University, Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan
| | - Ken-Ichi Yagyu
- Medical School, Kochi University, Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan
| | - Tatsuo Fukagawa
- Department of Molecular Genetics, National Institute of Genetics and the Graduate University for Advanced Studies, Mishima, Shizuoka 411-8540, Japan
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
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24
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Ferreira JG, Pereira AL, Maiato H. Microtubule plus-end tracking proteins and their roles in cell division. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 309:59-140. [PMID: 24529722 DOI: 10.1016/b978-0-12-800255-1.00002-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Microtubules are cellular components that are required for a variety of essential processes such as cell motility, mitosis, and intracellular transport. This is possible because of the inherent dynamic properties of microtubules. Many of these properties are tightly regulated by a number of microtubule plus-end-binding proteins or +TIPs. These proteins recognize the distal end of microtubules and are thus in the right context to control microtubule dynamics. In this review, we address how microtubule dynamics are regulated by different +TIP families, focusing on how functionally diverse +TIPs spatially and temporally regulate microtubule dynamics during animal cell division.
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Affiliation(s)
- Jorge G Ferreira
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, University of Porto, Porto, Portugal; Cell Division Unit, Department of Experimental Biology, University of Porto, Porto, Portugal
| | - Ana L Pereira
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, University of Porto, Porto, Portugal
| | - Helder Maiato
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, University of Porto, Porto, Portugal; Cell Division Unit, Department of Experimental Biology, University of Porto, Porto, Portugal.
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25
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Moorhouse KS, Burgess DR. How to be at the right place at the right time: the importance of spindle positioning in embryos. Mol Reprod Dev 2014; 81:884-95. [PMID: 25258000 DOI: 10.1002/mrd.22418] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 08/26/2014] [Indexed: 01/03/2023]
Abstract
Spindle positioning is an imperative cellular process that regulates a number of different developmental events throughout embryogenesis. The spindle must be properly positioned in embryos not only for the segregation of chromosomes, but also to segregate developmental determinants into different daughter blastomeres. In this review, the role of spindle positioning is explored in several different developmental model systems, which have revealed the diversity of factors that regulate spindle positioning. The C. elegans embryo, the Drosophila neuroblast, and ascidian embryos have all been utilized for the study of polarity-dependent spindle positioning, and exploration of the proteins that are required for asymmetric cell division. Work in the sea urchin embryo has examined the influence of cell shape and factors that affect secondary furrow formation. The issue of size scaling in extremely large cells, as well as the requirement for spindle positioning in developmental fate decisions in vertebrates, has been addressed by work in the Xenopus embryo. Further work in mouse oocytes has examined the roles of actin and myosin in spindle positioning. The data generated from these model organisms have made unique contributions to our knowledge of spindle positioning. Future work will address how all of these different factors work together to regulate the position of the spindle.
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26
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In situ imaging in C. elegans reveals developmental regulation of microtubule dynamics. Dev Cell 2014; 29:203-16. [PMID: 24780738 DOI: 10.1016/j.devcel.2014.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 12/12/2013] [Accepted: 03/13/2014] [Indexed: 11/20/2022]
Abstract
Microtubules (MTs) are cytoskeletal polymers that undergo dynamic instability, the stochastic transition between growth and shrinkage phases. MT dynamics are required for diverse cellular processes and, while intrinsic to tubulin, are highly regulated. However, little is known about how MT dynamics facilitate or are regulated by tissue biogenesis and differentiation. We imaged MT dynamics in a smooth muscle-like lineage in intact developing Caenorhabditis elegans. All aspects of MT dynamics change significantly as stem-like precursors exit mitosis and, secondarily, as they differentiate. We found that suppression, but not enhancement, of dynamics perturbs differentiated muscle function in vivo. Distinct ensembles of MT-associated proteins are specifically required for tissue biogenesis versus tissue function. A CLASP family MT stabilizer and the depolymerizing kinesin MCAK are differentially required for MT dynamics in the precursor or differentiated cells, respectively. All of these multidimensional phenotypic comparisons were facilitated by a data display method called the diamond graph.
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27
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Abstract
Accurate positioning of the mitotic spindle is critical to ensure proper distribution of chromosomes during cell division. The small GTPase Ran, which regulates a variety of processes throughout the cell cycle, including interphase nucleocytoplasmic transport and mitotic spindle assembly, was recently shown to also control spindle alignment. Ran is required for the correct cortical localization of LGN and nuclear-mitotic apparatus protein (NuMA), proteins that generate pulling forces on astral microtubules (MTs) through cytoplasmic dynein. Here we use importazole, a small-molecule inhibitor of RanGTP/importin-β function, to study the role of Ran in spindle positioning in human cells. We find that importazole treatment results in defects in astral MT dynamics, as well as in mislocalization of LGN and NuMA, leading to misoriented spindles. Of interest, importazole-induced spindle-centering defects can be rescued by nocodazole treatment, which depolymerizes astral MTs, or by overexpression of CLASP1, which does not restore proper LGN and NuMA localization but stabilizes astral MT interactions with the cortex. Together our data suggest a model for mitotic spindle positioning in which RanGTP and CLASP1 cooperate to align the spindle along the long axis of the dividing cell.
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Affiliation(s)
- Stephen L Bird
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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28
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Abstract
Accurate positioning of spindles is essential for asymmetric mitotic and meiotic cell divisions that are crucial for animal development and oocyte maturation, respectively. The predominant model for spindle positioning, termed "cortical pulling," involves attachment of the microtubule-based motor cytoplasmic dynein to the cortex, where it exerts a pulling force on microtubules that extend from the spindle poles to the cell cortex, thereby displacing the spindle. Recent studies have addressed important details of the cortical pulling mechanism and have revealed alternative mechanisms that may be used when microtubules do not extend from the spindle to the cortex.
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Affiliation(s)
- Francis J McNally
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA.
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