51
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Macaulay AD, Allais A, FitzHarris G. Chromosome dynamics and spindle microtubule establishment in mouse embryos. FASEB J 2020; 34:8057-8067. [PMID: 32329130 DOI: 10.1096/fj.201902947r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 03/25/2020] [Accepted: 03/31/2020] [Indexed: 11/11/2022]
Abstract
Chromosome segregation errors in mammalian embryos are common and jeopardize embryo health. Here, we perform for the first time 4-Dimensional imaging and tracking of chromosomes and centromeres through each preimplantation mitotic cell division in mouse embryos to define the normal dynamics of chromosome segregation. We show that a microtubule (MT)-dependent inward movement of chromosomes occurs at the time of nuclear envelope breakdown (NEBD), particularly in the earliest cell divisions, to position chromosomes prior to spindle assembly. Establishment of a rudimentary metaphase plate occurs immediately after NEBD, and is followed by a progressive alignment and biorientation of mitotic chromosomes. Stable end-on kinetochore-MT attachments form rapidly and attachment errors are uncommon. Altogether our data describe a rapid and efficient spindle assembly pathway that apparently minimizes the need for canonical MT attachment error correction in normally dividing embryos.
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Affiliation(s)
- Angus D Macaulay
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada
| | - Adélaïde Allais
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada
| | - Greg FitzHarris
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.,Department of OBGYN, Université de Montréal, Montreal, QC, Canada
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52
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Functional Dissection of Mitosis Using Immortalized Fibroblasts from the Indian Muntjac, a Placental Mammal with Only Three Chromosomes. Methods Mol Biol 2020; 2101:247-266. [PMID: 31879909 DOI: 10.1007/978-1-0716-0219-5_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
During cell division in eukaryotes a microtubule-based network undergoes drastic changes and remodeling to assemble a mitotic spindle competent to segregate chromosomes. Several model systems have been widely used to dissect the molecular and structural mechanisms behind mitotic spindle assembly and function. These include budding and fission yeasts, which are ideal for genetic and molecular approaches, but show limitations in high-resolution live-cell imaging, while being evolutionarily distant from humans. On the other hand, systems that were historically used for their exceptional properties for live-cell imaging of mitosis (e.g., newt lung cells and Haemanthus endosperm cells) lack the necessary genomic tools for molecular studies. In a CRISPR-Cas9 era, human cultured cells have conquered the privilege to be positioned among the most powerful genetically manipulatable systems, but their high chromosome number remains a significant bottleneck for the molecular dissection of mitosis in mammals. We believe that we can significantly broaden this scenario by establishing a unique placental mammal model system that combines the powerful genetic tools and low chromosome number of fission yeast and Drosophila melanogaster, with the exceptional cytological features of a rat kangaroo cell. This system is based on hTERT-immortalized fibroblasts from a female Indian muntjac, a placental mammal with the lowest known chromosome number (n = 3). Here we describe a series of methodologies established in our laboratory for the study of mitosis in Indian muntjac. These include standard techniques such as immunofluorescence, western blotting, and FISH, but also several state-of-the-art methodologies, including live-cell imaging, cell confinement, RNAi, super-resolution STED microscopy, and laser microsurgery.
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53
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The Mitotic Apparatus and Kinetochores in Microcephaly and Neurodevelopmental Diseases. Cells 2019; 9:cells9010049. [PMID: 31878213 PMCID: PMC7016623 DOI: 10.3390/cells9010049] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/18/2019] [Accepted: 12/21/2019] [Indexed: 12/15/2022] Open
Abstract
Regulators of mitotic division, when dysfunctional or expressed in a deregulated manner (over- or underexpressed) in somatic cells, cause chromosome instability, which is a predisposing condition to cancer that is associated with unrestricted proliferation. Genes encoding mitotic regulators are growingly implicated in neurodevelopmental diseases. Here, we briefly summarize existing knowledge on how microcephaly-related mitotic genes operate in the control of chromosome segregation during mitosis in somatic cells, with a special focus on the role of kinetochore factors. Then, we review evidence implicating mitotic apparatus- and kinetochore-resident factors in the origin of congenital microcephaly. We discuss data emerging from these works, which suggest a critical role of correct mitotic division in controlling neuronal cell proliferation and shaping the architecture of the central nervous system.
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54
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Paim LMG, FitzHarris G. Tetraploidy causes chromosomal instability in acentriolar mouse embryos. Nat Commun 2019; 10:4834. [PMID: 31645568 PMCID: PMC6811537 DOI: 10.1038/s41467-019-12772-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 09/20/2019] [Indexed: 11/16/2022] Open
Abstract
Tetraploidisation is considered a common event in the evolution of chromosomal instability (CIN) in cancer cells. The current model for how tetraploidy drives CIN in mammalian cells is that a doubling of the number of centrioles that accompany the genome doubling event leads to multipolar spindle formation and chromosome segregation errors. By exploiting the unusual scenario of mouse blastomeres, which lack centrioles until the ~64-cell stage, we show that tetraploidy can drive CIN by an entirely distinct mechanism. Tetraploid blastomeres assemble bipolar spindles dictated by microtubule organising centres, and multipolar spindles are rare. Rather, kinetochore-microtubule turnover is altered, leading to microtubule attachment defects and anaphase chromosome segregation errors. The resulting blastomeres become chromosomally unstable and exhibit a dramatic increase in whole chromosome aneuploidies. Our results thus reveal an unexpected mechanism by which tetraploidy drives CIN, in which the acquisition of chromosomally-unstable microtubule dynamics contributes to chromosome segregation errors following tetraploidisation.
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Affiliation(s)
- Lia Mara Gomes Paim
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, H2X 0A9, Montreal, QC, Canada
| | - Greg FitzHarris
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, H2X 0A9, Montreal, QC, Canada.
- Département d'Obstétrique-Gynécologie, Université de Montréal, H3T 1C5, Montreal, QC, Canada.
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55
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Abstract
Chromosome segregation errors in human oocytes lead to aneuploid embryos that cause infertility and birth defects. Here we provide an overview of the chromosome-segregation process in the mammalian oocyte, highlighting mechanistic differences between oocytes and somatic cells that render oocytes so prone to segregation error. These differences include the extremely large size of the oocyte cytoplasm, the unique geometry of meiosis-I chromosomes, idiosyncratic function of the spindle assembly checkpoint, and dramatically altered oocyte cell-cycle control and spindle assembly, as compared to typical somatic cells. We summarise recent work suggesting that aging leads to a further deterioration in fidelity of chromosome segregation by impacting multiple components of the chromosome-segregation machinery. In addition, we compare and contrast recent results from mouse and human oocytes, which exhibit overlapping defects to differing extents. We conclude that the striking propensity of the oocyte to mis-segregate chromosomes reflects the unique challenges faced by the spindle in a highly unusual cellular environment.
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Affiliation(s)
- Aleksandar I Mihajlović
- Centre Recherche CHUM and Department OBGYN, Université de Montreal, Montreal, Quebec, Canada
| | - Greg FitzHarris
- Centre Recherche CHUM and Department OBGYN, Université de Montreal, Montreal, Quebec, Canada.
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56
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Guo L, Mohd KS, Ren H, Xin G, Jiang Q, Clarke PR, Zhang C. Phosphorylation of importin-α1 by CDK1-cyclin B1 controls mitotic spindle assembly. J Cell Sci 2019; 132:jcs232314. [PMID: 31434716 PMCID: PMC6765185 DOI: 10.1242/jcs.232314] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 08/09/2019] [Indexed: 12/22/2022] Open
Abstract
Importin-α serves as an adaptor linking importin-β to proteins carrying a nuclear localization sequence (NLS). During interphase, this interaction enables nuclear protein import, while in mitosis it regulates spindle assembly factors (SAFs) and controls microtubule nucleation, stabilization and spindle function. Here, we show that human importin-α1 is regulated during the cell cycle and is phosphorylated at two sites (threonine 9 and serine 62) during mitosis by the major mitotic protein kinase CDK1-cyclin B. Mutational analysis indicates that the mitotic phosphorylation of importin-α1 inhibits its binding to importin-β and promotes the release of TPX2 and KIFC1, which are then targeted like importin-β to the spindle. Loss of importin-α1 or expression of a non-phosphorylated mutant of importin-α1 results in the formation of shortened spindles with reduced microtubule density and induces a prolonged metaphase, whereas phosphorylation-mimicking mutants are functional in mitosis. We propose that phosphorylation of importin-α1 is a general mechanism for the spatial and temporal control of mitotic spindle assembly by CDK1-cyclin B1 that acts through the release of SAFs such as TPX2 and KIFC1 from inhibitory complexes that restrict spindle assembly.
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Affiliation(s)
- Li Guo
- The MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing 100871, China
| | - Khamsah Suryati Mohd
- School of Medicine, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - He Ren
- The MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing 100871, China
| | - Guangwei Xin
- The MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing 100871, China
| | - Qing Jiang
- The MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing 100871, China
| | - Paul R Clarke
- School of Medicine, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, Brisbane, QLD 4102, Australia
| | - Chuanmao Zhang
- The MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing 100871, China
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57
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Adib R, Montgomery JM, Atherton J, O'Regan L, Richards MW, Straatman KR, Roth D, Straube A, Bayliss R, Moores CA, Fry AM. Mitotic phosphorylation by NEK6 and NEK7 reduces the microtubule affinity of EML4 to promote chromosome congression. Sci Signal 2019; 12:eaaw2939. [PMID: 31409757 DOI: 10.1126/scisignal.aaw2939] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
EML4 is a microtubule-associated protein that promotes microtubule stability. We investigated its regulation across the cell cycle and found that EML4 was distributed as punctate foci along the microtubule lattice in interphase but exhibited reduced association with spindle microtubules in mitosis. Microtubule sedimentation and cryo-electron microscopy with 3D reconstruction revealed that the basic N-terminal domain of EML4 mediated its binding to the acidic C-terminal tails of α- and β-tubulin on the microtubule surface. The mitotic kinases NEK6 and NEK7 phosphorylated the EML4 N-terminal domain at Ser144 and Ser146 in vitro, and depletion of these kinases in cells led to increased EML4 binding to microtubules in mitosis. An S144A-S146A double mutant not only bound inappropriately to mitotic microtubules but also increased their stability and interfered with chromosome congression. In addition, constitutive activation of NEK6 or NEK7 reduced the association of EML4 with interphase microtubules. Together, these data support a model in which NEK6- and NEK7-dependent phosphorylation promotes the dissociation of EML4 from microtubules in mitosis in a manner that is required for efficient chromosome congression.
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Affiliation(s)
- Rozita Adib
- Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Jessica M Montgomery
- Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Joseph Atherton
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Laura O'Regan
- Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Mark W Richards
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Kees R Straatman
- Centre for Core Biotechnology Services, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Daniel Roth
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Anne Straube
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Richard Bayliss
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Andrew M Fry
- Department of Molecular and Cell Biology, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
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58
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Akera T, Trimm E, Lampson MA. Molecular Strategies of Meiotic Cheating by Selfish Centromeres. Cell 2019; 178:1132-1144.e10. [PMID: 31402175 DOI: 10.1016/j.cell.2019.07.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 01/11/2019] [Accepted: 06/25/2019] [Indexed: 10/26/2022]
Abstract
Asymmetric division in female meiosis creates selective pressure favoring selfish centromeres that bias their transmission to the egg. This centromere drive can explain the paradoxical rapid evolution of both centromere DNA and centromere-binding proteins despite conserved centromere function. Here, we define a molecular pathway linking expanded centromeres to histone phosphorylation and recruitment of microtubule destabilizing factors, leading to detachment of selfish centromeres from spindle microtubules that would direct them to the polar body. Exploiting centromere divergence between species, we show that selfish centromeres in two hybrid mouse models use the same molecular pathway but modulate it differently to enrich destabilizing factors. Our results indicate that increasing microtubule destabilizing activity is a general strategy for drive in both models, but centromeres have evolved distinct mechanisms to increase that activity. Furthermore, we show that drive depends on slowing meiotic progression, suggesting that selfish centromeres can be suppressed by regulating meiotic timing.
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Affiliation(s)
- Takashi Akera
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Emily Trimm
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael A Lampson
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA.
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59
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Verma V, Maresca TJ. Direct observation of branching MT nucleation in living animal cells. J Cell Biol 2019; 218:2829-2840. [PMID: 31340987 PMCID: PMC6719462 DOI: 10.1083/jcb.201904114] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/07/2019] [Accepted: 07/01/2019] [Indexed: 02/07/2023] Open
Abstract
Branching microtubule nucleation by its molecular mediators has never been directly observed in animal cells. By imaging augmin, γ-TuRC, and microtubules with high spatiotemporal resolution, Verma and Maresca quantitatively define the sequential steps of augmin-mediated branching microtubule nucleation in dividing Drosophila cells. Centrosome-mediated microtubule (MT) nucleation has been well characterized; however, numerous noncentrosomal MT nucleation mechanisms exist. The branching MT nucleation pathway envisages that the γ-tubulin ring complex (γ-TuRC) is recruited to MTs by the augmin complex to initiate nucleation of new MTs. While the pathway is well conserved at a molecular and functional level, branching MT nucleation by core constituents has never been directly observed in animal cells. Here, multicolor TIRF microscopy was applied to visualize and quantitatively define the entire process of branching MT nucleation in dividing Drosophila cells during anaphase. The steps of a stereotypical branching nucleation event entailed augmin binding to a mother MT and recruitment of γ-TuRC after 15 s, followed by nucleation 16 s later of a daughter MT at a 36° branch angle. Daughters typically remained attached throughout their ∼40-s lifetime unless the mother depolymerized past the branch point. Assembly of branched MT arrays, which did not require Drosophila TPX2, enhanced localized RhoA activation during cytokinesis.
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Affiliation(s)
- Vikash Verma
- Biology Department, University of Massachusetts, Amherst, MA
| | - Thomas J Maresca
- Biology Department, University of Massachusetts, Amherst, MA .,Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA
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60
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Mascanzoni F, Ayala I, Colanzi A. Organelle Inheritance Control of Mitotic Entry and Progression: Implications for Tissue Homeostasis and Disease. Front Cell Dev Biol 2019; 7:133. [PMID: 31396510 PMCID: PMC6664238 DOI: 10.3389/fcell.2019.00133] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/04/2019] [Indexed: 12/12/2022] Open
Abstract
The Golgi complex (GC), in addition to its well-known role in membrane traffic, is also actively involved in the regulation of mitotic entry and progression. In particular, during the G2 phase of the cell cycle, the Golgi ribbon is unlinked into isolated stacks. Importantly, this ribbon cleavage is required for G2/M transition, indicating that a "Golgi mitotic checkpoint" controls the correct segregation of this organelle. Then, during mitosis, the isolated Golgi stacks are disassembled, and this process is required for spindle formation. Moreover, recent evidence indicates that also proper mitotic segregation of other organelles, such as mitochondria, endosomes, and peroxisomes, is required for correct mitotic progression and/or spindle formation. Collectively, these observations imply that in addition to the control of chromosomes segregation, which is required to preserve the genetic information, the cells actively monitor the disassembly and redistribution of subcellular organelles in mitosis. Here, we provide an overview of the major structural reorganization of the GC and other organelles during G2/M transition and of their regulatory mechanisms, focusing on novel findings that have shed light on the basic processes that link organelle inheritance to mitotic progression and spindle formation, and discussing their implications for tissue homeostasis and diseases.
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Affiliation(s)
| | | | - Antonino Colanzi
- Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
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61
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Wu DZ, Lackner RM, Aonbangkhen C, Lampson MA, Chenoweth DM. Reversible optogenetic control of protein function and localization. Methods Enzymol 2019; 624:25-45. [PMID: 31370933 DOI: 10.1016/bs.mie.2019.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Protein-protein interactions are highly dynamic biological processes that regulate various cellular reactions. They exhibit high specificity and spatiotemporal control in order to efficiently utilize finite resources in a cellular compartment. Photoactivatable chemically inducible dimerization (pCID) has emerged as an attractive technique in the scientific community, leading to the development of systems that can be activated with various wavelengths of light in order to manipulate processes on biologically relevant scales with molecular specificity. These systems can be modified to control various protein functions with unprecedented precision and spatiotemporal resolution. In this chapter, we describe an optogenetic platform that provides reversible control over dimerization of genetically tagged proteins using orthogonal wavelengths of light. We demonstrate photoactivation and photo-reversal of protein localization and transport. Mitosis is manipulated by activating and silencing the spindle assembly checkpoint through recruitment and release of proteins from kinetochores.
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Affiliation(s)
- Daniel Z Wu
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Rachel M Lackner
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Chanat Aonbangkhen
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael A Lampson
- Lynch Laboratories, Department of Biology, University of Pennsylvania, Philadelphia, PA, United States
| | - David M Chenoweth
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States.
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62
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Chowdhury D. Laying Tracks for Poison Delivery to "Kiss of Death": Search for Immune Synapse by Microtubules. Biophys J 2019; 116:2057-2059. [PMID: 31084901 DOI: 10.1016/j.bpj.2019.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 01/21/2023] Open
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63
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David AF, Roudot P, Legant WR, Betzig E, Danuser G, Gerlich DW. Augmin accumulation on long-lived microtubules drives amplification and kinetochore-directed growth. J Cell Biol 2019; 218:2150-2168. [PMID: 31113824 PMCID: PMC6605806 DOI: 10.1083/jcb.201805044] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 12/19/2018] [Accepted: 04/30/2019] [Indexed: 12/31/2022] Open
Abstract
Vertebrate cells assemble mitotic spindles through multiple pathways. It is shown that Augmin-dependent, noncentrosomal nucleation generates the vast majority of microtubules in metaphase spindles. This results in a strong directional bias of microtubule growth toward individual kinetochores. Dividing cells reorganize their microtubule cytoskeleton into a bipolar spindle, which moves one set of sister chromatids to each nascent daughter cell. Early spindle assembly models postulated that spindle pole–derived microtubules search the cytoplasmic space until they randomly encounter a kinetochore to form a stable attachment. More recent work uncovered several additional, centrosome-independent microtubule generation pathways, but the contributions of each pathway to spindle assembly have remained unclear. Here, we combined live microscopy and mathematical modeling to show that most microtubules nucleate at noncentrosomal regions in dividing human cells. Using a live-cell probe that selectively labels aged microtubule lattices, we demonstrate that the distribution of growing microtubule plus ends can be almost entirely explained by Augmin-dependent amplification of long-lived microtubule lattices. By ultrafast 3D lattice light-sheet microscopy, we observed that this mechanism results in a strong directional bias of microtubule growth toward individual kinetochores. Our systematic quantification of spindle dynamics reveals highly coordinated microtubule growth during kinetochore fiber assembly.
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Affiliation(s)
- Ana F David
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Philippe Roudot
- Department of Cell Biology and Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Wesley R Legant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - Eric Betzig
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA
| | - Gaudenz Danuser
- Department of Cell Biology and Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
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64
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BUB1 Is Essential for the Viability of Human Cells in which the Spindle Assembly Checkpoint Is Compromised. Cell Rep 2019; 22:1424-1438. [PMID: 29425499 DOI: 10.1016/j.celrep.2018.01.034] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 11/22/2022] Open
Abstract
The spindle assembly checkpoint (SAC) ensures faithful segregation of chromosomes. Although most mammalian cell types depend on the SAC for viability, we found that human HAP1 cells can grow SAC independently. We generated MAD1- and MAD2-deficient cells and mutagenized them to identify synthetic lethal interactions, revealing that chromosome congression factors become essential upon SAC deficiency. Besides expected hits, we also found that BUB1 becomes essential in SAC-deficient cells. We found that the BUB1 C terminus regulates alignment as well as recruitment of CENPF. Second, we found that BUBR1 was not essential in SAC-deficient HAP1 cells. We confirmed that BUBR1 does not regulate chromosome alignment in HAP1 cells and that BUB1 does not regulate chromosome alignment through BUBR1. Taken together, our data resolve some long-standing questions about the interplay between BUB1 and BUBR1 and their respective roles in the SAC and chromosome alignment.
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65
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Métivier M, Monroy BY, Gallaud E, Caous R, Pascal A, Richard-Parpaillon L, Guichet A, Ori-McKenney KM, Giet R. Dual control of Kinesin-1 recruitment to microtubules by Ensconsin in Drosophila neuroblasts and oocytes. Development 2019; 146:dev.171579. [PMID: 30936181 DOI: 10.1242/dev.171579] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 03/25/2019] [Indexed: 01/02/2023]
Abstract
Drosophila Ensconsin (also known as MAP7) controls spindle length, centrosome separation in brain neuroblasts (NBs) and asymmetric transport in oocytes. The control of spindle length by Ensconsin is Kinesin-1 independent but centrosome separation and oocyte transport require targeting of Kinesin-1 to microtubules by Ensconsin. However, the molecular mechanism used for this targeting remains unclear. Ensconsin contains a microtubule (MT)-binding domain (MBD) and a Kinesin-binding domain (KBD). Rescue experiments show that only full-length Ensconsin restores the spindle length phenotype. KBD expression rescues ensc centrosome separation defects in NBs, but not the fast oocyte streaming and the localization of Staufen and Gurken. Interestingly, the KBD can stimulate Kinesin-1 targeting to MTs in vivo and in vitro We propose that a KBD and Kinesin-1 complex is a minimal activation module that increases Kinesin-1 affinity for MTs. Addition of the MBD present in full-length Ensconsin allows this process to occur directly on the MT and triggers higher Kinesin-1 targeting. This dual regulation by Ensconsin is essential for optimal Kinesin-1 targeting to MTs in oocytes, but not in NBs, illustrating the importance of adapting Kinesin-1 recruitment to different biological contexts.
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Affiliation(s)
- Mathieu Métivier
- Univ. Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Brigette Y Monroy
- University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Emmanuel Gallaud
- Univ. Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Renaud Caous
- Univ. Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Aude Pascal
- Univ. Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Laurent Richard-Parpaillon
- Univ. Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Antoine Guichet
- Institut Jacques Monod-Université Paris Diderot-Paris 7, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
| | | | - Régis Giet
- Univ. Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
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66
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Dwivedi D, Kumari A, Rathi S, Mylavarapu SVS, Sharma M. The dynein adaptor Hook2 plays essential roles in mitotic progression and cytokinesis. J Cell Biol 2019; 218:871-894. [PMID: 30674580 PMCID: PMC6400558 DOI: 10.1083/jcb.201804183] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 10/29/2018] [Accepted: 12/07/2018] [Indexed: 12/16/2022] Open
Abstract
Hook proteins are evolutionarily conserved dynein adaptors that promote assembly of highly processive dynein-dynactin motor complexes. Mammals express three Hook paralogs, namely Hook1, Hook2, and Hook3, that have distinct subcellular localizations and expectedly, distinct cellular functions. Here we demonstrate that Hook2 binds to and promotes dynein-dynactin assembly specifically during mitosis. During the late G2 phase, Hook2 mediates dynein-dynactin localization at the nuclear envelope (NE), which is required for centrosome anchoring to the NE. Independent of its binding to dynein, Hook2 regulates microtubule nucleation at the centrosome; accordingly, Hook2-depleted cells have reduced astral microtubules and spindle positioning defects. Besides the centrosome, Hook2 localizes to and recruits dynactin and dynein to the central spindle. Dynactin-dependent targeting of centralspindlin complex to the midzone is abrogated upon Hook2 depletion; accordingly, Hook2 depletion results in cytokinesis failure. We find that the zebrafish Hook2 homologue promotes dynein-dynactin association and was essential for zebrafish early development. Together, these results suggest that Hook2 mediates assembly of the dynein-dynactin complex and regulates mitotic progression and cytokinesis.
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Affiliation(s)
- Devashish Dwivedi
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Amrita Kumari
- Laboratory of Cellular Dynamics, Regional Centre for Biotechnology, Faridabad, India.,Affiliated to Manipal Academy of Higher Education, Manipal, India
| | - Siddhi Rathi
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Sivaram V S Mylavarapu
- Laboratory of Cellular Dynamics, Regional Centre for Biotechnology, Faridabad, India.,Affiliated to Manipal Academy of Higher Education, Manipal, India
| | - Mahak Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
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67
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Pintard L, Bowerman B. Mitotic Cell Division in Caenorhabditis elegans. Genetics 2019; 211:35-73. [PMID: 30626640 PMCID: PMC6325691 DOI: 10.1534/genetics.118.301367] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/24/2018] [Indexed: 11/18/2022] Open
Abstract
Mitotic cell divisions increase cell number while faithfully distributing the replicated genome at each division. The Caenorhabditis elegans embryo is a powerful model for eukaryotic cell division. Nearly all of the genes that regulate cell division in C. elegans are conserved across metazoan species, including humans. The C. elegans pathways tend to be streamlined, facilitating dissection of the more redundant human pathways. Here, we summarize the virtues of C. elegans as a model system and review our current understanding of centriole duplication, the acquisition of pericentriolar material by centrioles to form centrosomes, the assembly of kinetochores and the mitotic spindle, chromosome segregation, and cytokinesis.
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Affiliation(s)
- Lionel Pintard
- Equipe labellisée Ligue contre le Cancer, Institut Jacques Monod, Team Cell Cycle and Development UMR7592, Centre National de la Recherche Scientifique - Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
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68
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Delayed Chromosome Alignment to the Spindle Equator Increases the Rate of Chromosome Missegregation in Cancer Cell Lines. Biomolecules 2018; 9:biom9010010. [PMID: 30597919 PMCID: PMC6359495 DOI: 10.3390/biom9010010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 12/22/2022] Open
Abstract
For appropriate chromosome segregation, kinetochores on sister chromatids have to attach to microtubules from opposite spindle poles (bi-orientation). Chromosome alignment at the spindle equator, referred to as congression, can occur through the attachment of kinetochores to the lateral surface of spindle microtubules, facilitating bi-orientation establishment. However, the contribution of this phenomenon to mitotic fidelity has not been clarified yet. Here, we addressed whether delayed chromosome alignment to the spindle equator increases the rate of chromosome missegregation. Cancer cell lines depleted of Kid, a chromokinesin involved in chromosome congression, showed chromosome alignment with a slight delay, and increased frequency of lagging chromosomes. Delayed chromosome alignment concomitant with an increased rate of lagging chromosomes was also seen in cells depleted of kinesin family member 4A (KIF4A), another chromokinesin. Cells that underwent chromosome missegregation took relatively longer time to align chromosomes in both control and Kid/KIF4A-depleted cells. Tracking of late-aligning chromosomes showed that they exhibit a higher rate of lagging chromosomes. Intriguingly, the metaphase of cells that underwent chromosome missegregation was shortened, and delaying anaphase onset ameliorated the increased chromosome missegregation. These data suggest that late-aligning chromosomes do not have sufficient time to establish bi-orientation, leading to chromosome missegregation. Our data imply that delayed chromosome alignment is not only a consequence, but also a cause of defective bi-orientation establishment, which can lead to chromosomal instability in cells without severe mitotic defects.
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69
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Liu C, Wei J, Xu K, Sun X, Zhang H, Xiong C. CSE1L participates in regulating cell mitosis in human seminoma. Cell Prolif 2018; 52:e12549. [PMID: 30485574 PMCID: PMC6496685 DOI: 10.1111/cpr.12549] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 09/28/2018] [Accepted: 10/16/2018] [Indexed: 12/12/2022] Open
Abstract
Objectives CSE1L has been reported to be highly expressed in various tumours. Testicular germ cell tumours are common among young males, and seminoma is the major type. However, whether CSE1L has functions in the seminoma is unclear. Materials and methods The expression of CSE1L was detected by immunohistochemistry in seminoma tissues and non‐tumour normal testis tissues from patients. CSE1L distribution during cell mitosis was determined by immunofluorescent staining with CSE1L, α‐tubulin and γ‐tubulin antibodies. The effects of Cse1L knockdown on cell proliferation and cell cycle progression were determined by Cell Counting Kit‐8 assay, flow cytometry, PH3 staining and bromodeoxyuridine incorporation assay. Results CSE1L was significantly enriched in the seminoma tissue compared with the non‐tumour normal testis tissue. CSE1L also co‐localized with α‐tubulin in the cells with a potential to divide. In the seminoma cell line TCam‐2, CSE1L was associated with the spindles and the centrosomes during cell division. The knockdown of CSE1L in TCam‐2 cells attenuated the cells’ proliferative capacity. Cell cycle assay revealed that the CSE1L‐deficient cells were mainly arrested in the G0/G1 phase and moderately delayed in the G2/M phase. The proportion of cells with multipolar spindle and abnormal spindle geometry was obviously increased by CSE1L expression silencing in the TCam‐2 cells. Conclusions Overall, these findings showed that CSE1L plays a pivotal role in maintaining cell proliferation and cell division in seminomas.
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Affiliation(s)
- Chunyan Liu
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiajing Wei
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kang Xu
- The First People's Hospital of Tianmen City, Tianmen, China
| | - Xiaosong Sun
- Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, China
| | - Huiping Zhang
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Wuhan Tongji Reproductive Medicine Hospital, Wuhan, Hubei, China
| | - Chengliang Xiong
- Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Wuhan Tongji Reproductive Medicine Hospital, Wuhan, Hubei, China
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70
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Suzuki A, Varma D. Cell Division: The Unattached Kinetochore Wears an Expansive RZZ Coat. Curr Biol 2018; 28:R1250-R1252. [PMID: 30399347 DOI: 10.1016/j.cub.2018.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The Rod-Zw10-Zwilch complex localizes to kinetochores during mitosis. New studies reveal that this complex plays a critical role in driving the expansion of the outer domain of unattached kinetochores, in addition to its known role in the control of the spindle assembly checkpoint.
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Affiliation(s)
- Aussie Suzuki
- McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA.
| | - Dileep Varma
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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71
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Elting MW, Suresh P, Dumont S. The Spindle: Integrating Architecture and Mechanics across Scales. Trends Cell Biol 2018; 28:896-910. [PMID: 30093097 PMCID: PMC6197898 DOI: 10.1016/j.tcb.2018.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/02/2018] [Accepted: 07/09/2018] [Indexed: 01/28/2023]
Abstract
The spindle segregates chromosomes at cell division, and its task is a mechanical one. While we have a nearly complete list of spindle components, how their molecular-scale mechanics give rise to cellular-scale spindle architecture, mechanics, and function is not yet clear. Recent in vitro and in vivo measurements bring new levels of molecular and physical control and shed light on this question. Highlighting recent findings and open questions, we introduce the molecular force generators of the spindle, and discuss how they organize microtubules into diverse architectural modules and give rise to the emergent mechanics of the mammalian spindle. Throughout, we emphasize the breadth of space and time scales at play, and the feedback between spindle architecture, dynamics, and mechanics that drives robust function.
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Affiliation(s)
- Mary Williard Elting
- Department of Cell & Tissue Biology, 513 Parnassus Ave, University of California, San Francisco, CA 94143, USA; Department of Physics, Riddick Hall 258A, Box 8202, North Carolina State University, Raleigh, NC 27695, USA; These authors contributed equally
| | - Pooja Suresh
- Department of Cell & Tissue Biology, 513 Parnassus Ave, University of California, San Francisco, CA 94143, USA; Biophysics Graduate Program, 513 Parnassus Ave, University of California, San Francisco, CA 94143, USA; These authors contributed equally
| | - Sophie Dumont
- Department of Cell & Tissue Biology, 513 Parnassus Ave, University of California, San Francisco, CA 94143, USA; Biophysics Graduate Program, 513 Parnassus Ave, University of California, San Francisco, CA 94143, USA; Department of Cellular & Molecular Pharmacology, 513 Parnassus Ave, University of California, San Francisco, CA 94143, USA.
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72
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LaFlamme SE, Mathew-Steiner S, Singh N, Colello-Borges D, Nieves B. Integrin and microtubule crosstalk in the regulation of cellular processes. Cell Mol Life Sci 2018; 75:4177-4185. [PMID: 30206641 PMCID: PMC6182340 DOI: 10.1007/s00018-018-2913-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 08/14/2018] [Accepted: 08/27/2018] [Indexed: 11/25/2022]
Abstract
Integrins engage components of the extracellular matrix, and in collaboration with other receptors, regulate signaling cascades that impact cell behavior in part by modulating the cell's cytoskeleton. Integrins have long been known to function together with the actin cytoskeleton to promote cell adhesion, migration, and invasion, and with the intermediate filament cytoskeleton to mediate the strong adhesion needed for the maintenance and integrity of epithelial tissues. Recent studies have shed light on the crosstalk between integrin and the microtubule cytoskeleton. Integrins promote microtubule nucleation, growth, and stabilization at the cell cortex, whereas microtubules regulate integrin activity and remodeling of adhesion sites. Integrin-dependent stabilization of microtubules at the cell cortex is critical to the establishment of apical-basal polarity required for the formation of epithelial tissues. During cell migration, integrin-dependent microtubule stabilization contributes to front-rear polarity, whereas microtubules promote the turnover of integrin-mediated adhesions. This review focuses on this interdependent relationship and its impact on cell behavior and function.
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Affiliation(s)
- Susan E LaFlamme
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, 47 New Scotland Avenue, Albany, NY, 12208, USA.
| | - Shomita Mathew-Steiner
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, 47 New Scotland Avenue, Albany, NY, 12208, USA
- Indiana University, 975 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - Neetu Singh
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, 47 New Scotland Avenue, Albany, NY, 12208, USA
| | - Diane Colello-Borges
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, 47 New Scotland Avenue, Albany, NY, 12208, USA
| | - Bethsaida Nieves
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, 47 New Scotland Avenue, Albany, NY, 12208, USA
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73
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Reconstitution of a 26-Subunit Human Kinetochore Reveals Cooperative Microtubule Binding by CENP-OPQUR and NDC80. Mol Cell 2018; 71:923-939.e10. [PMID: 30174292 PMCID: PMC6162344 DOI: 10.1016/j.molcel.2018.07.038] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/04/2018] [Accepted: 07/25/2018] [Indexed: 12/15/2022]
Abstract
The approximately thirty core subunits of kinetochores assemble on centromeric chromatin containing the histone H3 variant CENP-A and connect chromosomes with spindle microtubules. The chromatin proximal 16-subunit CCAN (constitutive centromere associated network) creates a mechanically stable bridge between CENP-A and the kinetochore’s microtubule-binding machinery, the 10-subunit KMN assembly. Here, we reconstituted a stoichiometric 11-subunit human CCAN core that forms when the CENP-OPQUR complex binds to a joint interface on the CENP-HIKM and CENP-LN complexes. The resulting CCAN particle is globular and connects KMN and CENP-A in a 26-subunit recombinant particle. The disordered, basic N-terminal tail of CENP-Q binds microtubules and promotes accurate chromosome alignment, cooperating with KMN in microtubule binding. The N-terminal basic tail of the NDC80 complex, the microtubule-binding subunit of KMN, can functionally replace the CENP-Q tail. Our work dissects the connectivity and architecture of CCAN and reveals unexpected functional similarities between CENP-OPQUR and the NDC80 complex. The kinetochore CENP-OPQUR complex is reconstituted and functionally dissected A kinetochore particle with 26 subunits and defined stoichiometry is reconstituted EM structure of an 11-subunit inner kinetochore complex reveals globular shape CENP-Q and the Ndc80 complex bind microtubules cooperatively
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74
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Reinemann DN, Norris SR, Ohi R, Lang MJ. Processive Kinesin-14 HSET Exhibits Directional Flexibility Depending on Motor Traffic. Curr Biol 2018; 28:2356-2362.e5. [PMID: 30017484 PMCID: PMC11009875 DOI: 10.1016/j.cub.2018.06.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/01/2018] [Accepted: 06/21/2018] [Indexed: 12/12/2022]
Abstract
A common mitotic defect observed in cancer cells that possess supernumerary (more than two) centrosomes is multipolar spindle formation [1, 2]. Such structures are resolved into a bipolar geometry by minus-end-directed motor proteins, such as cytoplasmic dynein and the kinesin-14 HSET [3-8]. HSET is also thought to antagonize plus-end-directed kinesin-5 Eg5 to balance spindle forces [4, 5, 7, 9]. However, the biomechanics of this force opposition are unclear, as HSET has previously been defined as a non-processive motor [10-16]. Here, we use optical trapping to elucidate the mechanism of force generation by HSET. We show that a single HSET motor has a processive nature with the ability to complete multiple steps while trapped along a microtubule and when unloaded can move in both directions for microns. Compared to other kinesins, HSET has a relatively weak stall force of 1.1 pN [17, 18]. Moreover, HSET's tail domain and its interaction with the E-hook of tubulin are necessary for long-range motility. In vitro polarity-marked bundle assays revealed that HSET selectively generates force in anti-parallel bundles on the order of its stall force. When combined with varied ratios of Eg5, HSET adopts Eg5's directionality while acting as an antagonizing force brake, requiring at least a 10-fold higher Eg5 concentration to surpass HSET's sliding force. These results reveal HSET's ability to change roles within the spindle from acting as an adjustable microtubule slider and force regulator to a processive motor that aids in minus end focusing.
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Affiliation(s)
- Dana N Reinemann
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Stephen R Norris
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Ryoma Ohi
- Department of Cell and Developmental Biology and LSI, University of Michigan School of Medicine, Ann Arbor, MI 48109-2216, USA
| | - Matthew J Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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75
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Sikirzhytski V, Renda F, Tikhonenko I, Magidson V, McEwen BF, Khodjakov A. Microtubules assemble near most kinetochores during early prometaphase in human cells. J Cell Biol 2018; 217:2647-2659. [PMID: 29907657 PMCID: PMC6080938 DOI: 10.1083/jcb.201710094] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 04/15/2018] [Accepted: 05/21/2018] [Indexed: 11/22/2022] Open
Abstract
Correlative light electron microscopy reveals microtubule assembly near most kinetochores at the onset of mitosis in human cells. Conversion of the initially lateral interactions between these microtubules and kinetochores into end-on attachments is facilitated by the kinesin CenpE. This work suggests that kinetochore fibers predominately form via capture of locally nucleated noncentrosomal microtubules. For proper segregation during cell division, each chromosome must connect to the poles of the spindle via microtubule bundles termed kinetochore fibers (K-fibers). K-fibers form by two distinct mechanisms: (1) capture of astral microtubules nucleated at the centrosome by the chromosomes’ kinetochores or (2) attachment of kinetochores to noncentrosomal microtubules with subsequent transport of the minus ends of these microtubules toward the spindle poles. The relative contributions of these alternative mechanisms to normal spindle assembly remain unknown. In this study, we report that most kinetochores in human cells develop K-fibers via the second mechanism. Correlative light electron microscopy demonstrates that from the onset of spindle assembly, short randomly oriented noncentrosomal microtubules appear in the immediate vicinity of the kinetochores. Initially, these microtubules interact with the kinetochores laterally, but end-on attachments form rapidly in the first 3 min of prometaphase. Conversion from lateral to end-on interactions is impeded upon inhibition of the plus end–directed kinetochore-associated kinesin CenpE.
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Affiliation(s)
| | - Fioranna Renda
- Wadsworth Center, New York State Department of Health, Albany, NY
| | - Irina Tikhonenko
- Wadsworth Center, New York State Department of Health, Albany, NY
| | | | - Bruce F McEwen
- Wadsworth Center, New York State Department of Health, Albany, NY
| | - Alexey Khodjakov
- Wadsworth Center, New York State Department of Health, Albany, NY .,Rensselaer Polytechnic Institute, Troy, NY
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76
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Burdyniuk M, Callegari A, Mori M, Nédélec F, Lénárt P. F-Actin nucleated on chromosomes coordinates their capture by microtubules in oocyte meiosis. J Cell Biol 2018; 217:2661-2674. [PMID: 29903878 PMCID: PMC6080919 DOI: 10.1083/jcb.201802080] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/04/2018] [Accepted: 05/23/2018] [Indexed: 11/22/2022] Open
Abstract
Capture of each and every chromosome by spindle microtubules is essential to prevent chromosome loss and aneuploidy. In somatic cells, astral microtubules search and capture chromosomes forming lateral attachments to kinetochores. However, this mechanism alone is insufficient in large oocytes. We have previously shown that a contractile F-actin network is additionally required to collect chromosomes scattered in the 70-µm starfish oocyte nucleus. How this F-actin-driven mechanism is coordinated with microtubule capture remained unknown. Here, we show that after nuclear envelope breakdown Arp2/3-nucleated F-actin "patches" form around chromosomes in a Ran-GTP-dependent manner, and we propose that these structures sterically block kinetochore-microtubule attachments. Once F-actin-driven chromosome transport is complete, coordinated disassembly of F-actin patches allows synchronous capture by microtubules. Our observations indicate that this coordination is necessary because early capture of chromosomes by microtubules would interfere with F-actin-driven transport leading to chromosome loss and formation of aneuploid eggs.
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Affiliation(s)
- Mariia Burdyniuk
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Andrea Callegari
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Masashi Mori
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - François Nédélec
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Péter Lénárt
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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77
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Augustine B, Chin CF, Yeong FM. Role of Kip2 during early mitosis - impact on spindle pole body separation and chromosome capture. J Cell Sci 2018; 131:jcs.211425. [PMID: 29739877 DOI: 10.1242/jcs.211425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 04/30/2018] [Indexed: 11/20/2022] Open
Abstract
Mitotic spindle dynamics are regulated during the cell cycle by microtubule motor proteins. In Saccharomyces cerevisiae, one such protein is Kip2p, a plus-end motor that regulates the polymerization and stability of cytoplasmic microtubules (cMTs). Kip2p levels are regulated during the cell cycle, and its overexpression leads to the formation of hyper-elongated cMTs. To investigate the significance of varying Kip2p levels during the cell cycle and the hyper-elongated cMTs, we overexpressed KIP2 in the G1 phase and examined the effects on the separation of spindle pole bodies (SPBs) and chromosome segregation. Our results show that failure to regulate the cMT lengths during G1-S phase prevents the separation of SPBs. This, in turn, affects chromosome capture and leads to the activation of spindle assembly checkpoint (SAC) and causes mitotic arrest. These defects could be rescued by either the inactivation of checkpoint components or by co-overexpression of CIN8, which encodes a motor protein that elongates inter-polar microtubules (ipMTs). Hence, we propose that the maintenance of Kip2p level and cMT lengths during early cell division is important to ensure coordination between SPB separation and chromosome capture by kinetochore microtubules (kMTs).
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Affiliation(s)
- Beryl Augustine
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545
| | - Cheen Fei Chin
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545
| | - Foong May Yeong
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545
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78
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Desmaison A, Guillaume L, Triclin S, Weiss P, Ducommun B, Lobjois V. Impact of physical confinement on nuclei geometry and cell division dynamics in 3D spheroids. Sci Rep 2018; 8:8785. [PMID: 29884887 PMCID: PMC5993719 DOI: 10.1038/s41598-018-27060-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 05/24/2018] [Indexed: 02/07/2023] Open
Abstract
Multicellular tumour spheroids are used as a culture model to reproduce the 3D architecture, proliferation gradient and cell interactions of a tumour micro-domain. However, their 3D characterization at the cell scale remains challenging due to size and cell density issues. In this study, we developed a methodology based on 3D light sheet fluorescence microscopy (LSFM) image analysis and convex hull calculation that allows characterizing the 3D shape and orientation of cell nuclei relative to the spheroid surface. By using this technique and optically cleared spheroids, we found that in freely growing spheroids, nuclei display an elongated shape and are preferentially oriented parallel to the spheroid surface. This geometry is lost when spheroids are grown in conditions of physical confinement. Live 3D LSFM analysis of cell division revealed that confined growth also altered the preferential cell division axis orientation parallel to the spheroid surface and induced prometaphase delay. These results provide key information and parameters that help understanding the impact of physical confinement on cell proliferation within tumour micro-domains.
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Affiliation(s)
| | | | - Sarah Triclin
- ITAV, Université de Toulouse, CNRS, Toulouse, France
| | - Pierre Weiss
- ITAV, Université de Toulouse, CNRS, Toulouse, France
- IMT, Université de Toulouse, CNRS, Toulouse, France
| | - Bernard Ducommun
- ITAV, Université de Toulouse, CNRS, Toulouse, France
- CHU de Toulouse, Toulouse, France
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79
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Dudka D, Noatynska A, Smith CA, Liaudet N, McAinsh AD, Meraldi P. Complete microtubule-kinetochore occupancy favours the segregation of merotelic attachments. Nat Commun 2018; 9:2042. [PMID: 29795284 PMCID: PMC5966435 DOI: 10.1038/s41467-018-04427-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 04/30/2018] [Indexed: 12/03/2022] Open
Abstract
Kinetochores are multi-protein complexes that power chromosome movements by tracking microtubules plus-ends in the mitotic spindle. Human kinetochores bind up to 20 microtubules, even though single microtubules can generate sufficient force to move chromosomes. Here, we show that high microtubule occupancy at kinetochores ensures robust chromosome segregation by providing a strong mechanical force that favours segregation of merotelic attachments during anaphase. Using low doses of the microtubules-targeting agent BAL27862 we reduce microtubule occupancy and observe that spindle morphology is unaffected and bi-oriented kinetochores can still oscillate with normal intra-kinetochore distances. Inter-kinetochore stretching is, however, dramatically reduced. The reduction in microtubule occupancy and inter-kinetochore stretching does not delay satisfaction of the spindle assembly checkpoint or induce microtubule detachment via Aurora-B kinase, which was so far thought to release microtubules from kinetochores under low stretching. Rather, partial microtubule occupancy slows down anaphase A and increases incidences of lagging chromosomes due to merotelically attached kinetochores. Single microtubules (MTs) can move chromosomes, but it is unclear why kinetochores bind up to 20 MTs. Here, the authors decrease the number of kinetochore MTs with BAL27862 and see lagging chromosomes, suggesting that numerous kinetochore MTs provide force ensuring robust chromosomal segregation.
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Affiliation(s)
- Damian Dudka
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland
| | - Anna Noatynska
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland
| | - Chris A Smith
- Centre for Mechanochemical Cell Biology & Division of Biomedical Sciences, Warwick Medical School, University of Warwick, CV4 7AL, Coventry, UK.,Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Nicolas Liaudet
- Bioimaging Facility, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland
| | - Andrew D McAinsh
- Centre for Mechanochemical Cell Biology & Division of Biomedical Sciences, Warwick Medical School, University of Warwick, CV4 7AL, Coventry, UK
| | - Patrick Meraldi
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland. .,Translational Research Centre in Onco-hematology, Faculty of Medicine, University of Geneva, 1211, Geneva 4, Switzerland.
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80
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Abstract
Mitosis is a highly dynamic process that depends on coordination of many protein-protein interactions with temporal and spatial precision. A challenge for understanding this complex system is to manipulate it on biologically relevant temporal and spatial scales, with molecular specificity. We describe an optogenetic platform, based on photosensitive chemical inducers of dimerization, which provides control over dimerization of genetically tagged proteins with light. As examples, we drive chromosome transport and activate and silence the spindle assembly checkpoint by recruiting proteins to and releasing them from kinetochores with light.
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81
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Jiao XF, Huang CJ, Wu D, Zhang JY, Long YT, Chen F, Li X, Huo LJ. Abce1 orchestrates M-phase entry and cytoskeleton architecture in mouse oocyte. Oncotarget 2018; 8:39012-39020. [PMID: 28380459 PMCID: PMC5503591 DOI: 10.18632/oncotarget.16546] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/22/2017] [Indexed: 01/01/2023] Open
Abstract
ATP-binding cassette E1 (ABCE1) is a member of the ATP-binding cassette transporters and essential for diverse biological events regulating abroad range of biological functions including viral infection, cell proliferation, anti-apoptosis, translation initiation and ribosome biogenesis. Here, we discovered that Abce1 also plays indispensable roles in mouse oocyte meiotic progression. In the present study, we examined the expression, localization, and function of Abce1 during mouse oocyte meiotic maturation. Immunostaining and confocal microscopy identified that Abce1 localized as small dots in nucleus in germinal vesicle stage. After germinal vesicle breakdown, it dispersedly localized around the whole spindle apparatus. During the anaphase and telophase stages, Abce1 was just like a cap to localize around the two pole region of spindle but not the midbody and chromosome. Knockdown of Abce1 by specific siRNA injection delayed the resumption of meiosis (GVBD) and affected the extrusion of first polar body. Moreover, the process of spindle assembly and chromosome alignment were severely impaired. Abce1-RNAi led to the dissociation of γ-tubulin and p-MAPK from spindle poles, thus caused mounts of spindle morphology abnormities and chromosome alignment defects, leading to high incidence of aneuploidy. Our findings refresh the knowledge of Abce1 function by exploring its role in oocyte meiotic resumption, spindle assembly and chromosome alignment.
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Affiliation(s)
- Xiao-Fei Jiao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Chun-Jie Huang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Di Wu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jia-Yu Zhang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yu-Ting Long
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fan Chen
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xiang Li
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Li-Jun Huo
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, Wuhan, China.,College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
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82
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Tolić IM. Mitotic spindle: kinetochore fibers hold on tight to interpolar bundles. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2018; 47:191-203. [PMID: 28725997 PMCID: PMC5845649 DOI: 10.1007/s00249-017-1244-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/30/2017] [Accepted: 07/02/2017] [Indexed: 12/24/2022]
Abstract
When a cell starts to divide, it forms a spindle, a micro-machine made of microtubules, which separates the duplicated chromosomes. The attachment of microtubules to chromosomes is mediated by kinetochores, protein complexes on the chromosome. Spindle microtubules can be divided into three major classes: kinetochore microtubules, which form k-fibers ending at the kinetochore; interpolar microtubules, which extend from the opposite sides of the spindle and interact in the middle; and astral microtubules, which extend towards the cell cortex. Recent work in human cells has shown a close relationship between interpolar and kinetochore microtubules, where interpolar bundles are attached laterally to kinetochore fibers almost all along their length, acting as a bridge between sister k-fibers. Most of the interpolar bundles are attached to a pair of sister kinetochore fibers and vice versa. Thus, the spindle is made of modules consisting of a pair of sister kinetochore fibers and a bundle of interpolar microtubules that connects them. These interpolar bundles, termed bridging fibers, balance the forces acting at kinetochores and support the rounded shape of the spindle during metaphase. This review discusses the structure, function, and formation of kinetochore fibers and interpolar bundles, with an emphasis on how they interact. Their connections have an impact on the force balance in the spindle and on chromosome movement during mitosis because the forces in interpolar bundles are transmitted to kinetochore fibers and hence to kinetochores through these connections.
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Affiliation(s)
- Iva M Tolić
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000, Zagreb, Croatia.
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83
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Ran J, Luo Y, Zhang Y, Yang Y, Chen M, Liu M, Li D, Zhou J. Phosphorylation of EB1 regulates the recruitment of CLIP-170 and p150glued to the plus ends of astral microtubules. Oncotarget 2018; 8:9858-9867. [PMID: 28039481 PMCID: PMC5354776 DOI: 10.18632/oncotarget.14222] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 11/24/2016] [Indexed: 12/31/2022] Open
Abstract
Phosphorylation of end-binding protein 1 (EB1), a key member of microtubule plus end-tracking proteins (+TIPs), by apoptosis signal-regulating kinase 1 (ASK1) has been demonstrated to promote the stability of astral microtubules during mitosis by stimulating the binding of EB1 to microtubule plus ends. However, the roles of other members of the +TIPs family in ASK1/EB1-mediated regulation of astral microtubules are unknown. Herein, we show that ASK1-mediated phosphorylation of EB1 enhances the localization of cytoplasmic linker protein 170 (CLIP-170) and p150glued to the plus ends of astral microtubules. Depletion of ASK1 or expression of phospho-deficient or phospho-mimetic EB1 mutants results in changes in the levels of plus-end localized CLIP-170 or p150glued. Mechanistic studies reveal that EB1 phosphorylation promotes its interactions with CLIP-170 and p150glued, thereby recruiting these +TIPs to microtubules. Structural analysis suggests that serine-40 is the primary phosphorylation site on EB1 that exerts these effects. Together, these findings provide novel insight into the molecular mechanisms that regulate the interactions of EB1 with other +TIPs.
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Affiliation(s)
- Jie Ran
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong 250014, China
| | - Youguang Luo
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yijun Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yang Yang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Miao Chen
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong 250014, China
| | - Min Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong 250014, China
| | - Dengwen Li
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jun Zhou
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong 250014, China.,State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
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84
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Howes SC, Geyer EA, LaFrance B, Zhang R, Kellogg EH, Westermann S, Rice LM, Nogales E. Structural and functional differences between porcine brain and budding yeast microtubules. Cell Cycle 2018; 17:278-287. [PMID: 29278985 PMCID: PMC5914886 DOI: 10.1080/15384101.2017.1415680] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The cytoskeleton of eukaryotic cells relies on microtubules to perform many essential functions. We have previously shown that, in spite of the overall conservation in sequence and structure of tubulin subunits across species, there are differences between mammalian and budding yeast microtubules with likely functional consequences for the cell. Here we expand our structural and function comparison of yeast and porcine microtubules to show different distribution of protofilament number in microtubules assembled in vitro from these two species. The different geometry at lateral contacts between protofilaments is likely due to a more polar interface in yeast. We also find that yeast tubulin forms longer and less curved oligomers in solution, suggesting stronger tubulin:tubulin interactions along the protofilament. Finally, we observed species-specific plus-end tracking activity for EB proteins: yeast Bim1 tracked yeast but not mammalian MTs, and human EB1 tracked mammalian but not yeast MTs. These findings further demonstrate that subtle sequence differences in tubulin sequence can have significant structural and functional consequences in microtubule structure and behavior.
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Affiliation(s)
- Stuart C Howes
- a Biophysics Graduate Group , UC Berkeley , CA 94720 , USA and Department of Molecular Cell Biology , Leiden University Medical Center , 2333 ZC Leiden , Netherlands
| | - Elisabeth A Geyer
- b UT Southwestern Medical Center , Departments of Biophysics and Biochemistry , Dallas , TX 75390 , USA
| | - Benjamin LaFrance
- c Molecular and Cell Biology Graduate Program , UC Berkeley , CA 94720 , USA
| | - Rui Zhang
- d Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , CA 94720 , USA.,e Howard Hughes Medical Institute , UC Berkeley , CA 94720-3220 , USA.,f Department of Biochemistry and Molecular Biophysics , Washington University School of Medicine , St. Louis , MO 63110 , USA
| | - Elizabeth H Kellogg
- d Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , CA 94720 , USA.,e Howard Hughes Medical Institute , UC Berkeley , CA 94720-3220 , USA
| | - Stefan Westermann
- g Research Institute of Molecular Pathology , Dr. Bohr-Gasse 7, 1030 Vienna , Austria
| | - Luke M Rice
- b UT Southwestern Medical Center , Departments of Biophysics and Biochemistry , Dallas , TX 75390 , USA
| | - Eva Nogales
- d Molecular Biophysics and Integrated Bioimaging , Lawrence Berkeley National Laboratory , CA 94720 , USA.,e Howard Hughes Medical Institute , UC Berkeley , CA 94720-3220 , USA.,h Molecular and Cell Biology Department and QB3 Institute , UC Berkeley , CA 94720 , USA
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85
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Vázquez-Diez C, FitzHarris G. Causes and consequences of chromosome segregation error in preimplantation embryos. Reproduction 2018; 155:R63-R76. [DOI: 10.1530/rep-17-0569] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 10/19/2017] [Accepted: 11/06/2017] [Indexed: 01/04/2023]
Abstract
Errors in chromosome segregation are common during the mitotic divisions of preimplantation development in mammalian embryos, giving rise to so-called ‘mosaic’ embryos possessing a mixture of euploid and aneuploid cells. Mosaicism is widely considered to be detrimental to embryo quality and is frequently used as criteria to select embryos for transfer in human fertility clinics. However, despite the clear clinical importance, the underlying defects in cell division that result in mosaic aneuploidy remain elusive. In this review, we summarise recent findings from clinical and animal model studies that provide new insights into the fundamental mechanisms of chromosome segregation in the highly unusual cellular environment of early preimplantation development and consider recent clues as to why errors should commonly occur in this setting. We furthermore discuss recent evidence suggesting that mosaicism is not an irrevocable barrier to a healthy pregnancy. Understanding the causes and biological impacts of mosaic aneuploidy will be pivotal in the development and fine-tuning of clinical embryo selection methods.
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86
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Yukawa M, Kawakami T, Okazaki M, Kume K, Tang NH, Toda T. A microtubule polymerase cooperates with the kinesin-6 motor and a microtubule cross-linker to promote bipolar spindle assembly in the absence of kinesin-5 and kinesin-14 in fission yeast. Mol Biol Cell 2017; 28:3647-3659. [PMID: 29021344 PMCID: PMC5706992 DOI: 10.1091/mbc.e17-08-0497] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/26/2017] [Accepted: 10/03/2017] [Indexed: 12/16/2022] Open
Abstract
Kinesin-5 is required for bipolar spindle assembly; yet in the absence of kinesins-5 and -14, cells can form spindles. In fission yeast, three distinct pathways compensate for their loss. Microtubule polymerase, kinesin-6, and microtubule cross-linker execute individual roles in concert at different mitotic stages in place of the two kinesins. Accurate chromosome segregation relies on the bipolar mitotic spindle. In many eukaryotes, spindle formation is driven by the plus-end–directed motor kinesin-5 that generates outward force to establish spindle bipolarity. Its inhibition leads to the emergence of monopolar spindles with mitotic arrest. Intriguingly, simultaneous inactivation of the minus-end–directed motor kinesin-14 restores spindle bipolarity in many systems. Here we show that in fission yeast, three independent pathways contribute to spindle bipolarity in the absence of kinesin-5/Cut7 and kinesin-14/Pkl1. One is kinesin-6/Klp9 that engages with spindle elongation once short bipolar spindles assemble. Klp9 also ensures the medial positioning of anaphase spindles to prevent unequal chromosome segregation. Another is the Alp7/TACC-Alp14/TOG microtubule polymerase complex. Temperature-sensitive alp7cut7pkl1 mutants are arrested with either monopolar or very short spindles. Forced targeting of Alp14 to the spindle pole body is sufficient to render alp7cut7pkl1 triply deleted cells viable and promote spindle assembly, indicating that Alp14-mediated microtubule polymerization from the nuclear face of the spindle pole body could generate outward force in place of Cut7 during early mitosis. The third pathway involves the Ase1/PRC1 microtubule cross-linker that stabilizes antiparallel microtubules. Our study, therefore, unveils multifaceted interplay among kinesin-dependent and -independent pathways leading to mitotic bipolar spindle assembly.
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Affiliation(s)
- Masashi Yukawa
- Hiroshima Research Center for Healthy Aging, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan .,Laboratory of Molecular and Chemical Cell Biology, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Tomoki Kawakami
- Hiroshima Research Center for Healthy Aging, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan.,Laboratory of Molecular and Chemical Cell Biology, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Masaki Okazaki
- Hiroshima Research Center for Healthy Aging, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan.,Laboratory of Molecular and Chemical Cell Biology, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Kazunori Kume
- Hiroshima Research Center for Healthy Aging, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan.,Laboratory of Cell Biology, Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Ngang Heok Tang
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Takashi Toda
- Hiroshima Research Center for Healthy Aging, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan .,Laboratory of Molecular and Chemical Cell Biology, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
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87
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Zhang H, Aonbangkhen C, Tarasovetc EV, Ballister ER, Chenoweth DM, Lampson MA. Optogenetic control of kinetochore function. Nat Chem Biol 2017; 13:1096-1101. [PMID: 28805800 PMCID: PMC5605432 DOI: 10.1038/nchembio.2456] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 07/17/2017] [Indexed: 12/15/2022]
Abstract
Kinetochores act as hubs for multiple activities during cell division, including microtubule interactions and spindle checkpoint signaling. Each kinetochore can act autonomously, and activities change rapidly as proteins are recruited to, or removed from, kinetochores. Understanding this dynamic system requires tools that can manipulate kinetochores on biologically relevant temporal and spatial scales. Optogenetic approaches have the potential to provide temporal and spatial control with molecular specificity. Here we report new chemical inducers of protein dimerization that allow us to both recruit proteins to and release them from kinetochores using light. We use these dimerizers to manipulate checkpoint signaling and molecular motor activity. Our findings demonstrate specialized properties of the CENP-E (kinesin-7) motor for directional chromosome transport to the spindle equator and for maintenance of metaphase alignment. This work establishes a foundation for optogenetic control of kinetochore function, which is broadly applicable to experimental probing of other dynamic cellular processes.
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Affiliation(s)
- Huaiying Zhang
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Chanat Aonbangkhen
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Ekaterina V. Tarasovetc
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Edward R. Ballister
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - David M. Chenoweth
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Michael A. Lampson
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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88
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Reinemann DN, Sturgill EG, Das DK, Degen MS, Vörös Z, Hwang W, Ohi R, Lang MJ. Collective Force Regulation in Anti-parallel Microtubule Gliding by Dimeric Kif15 Kinesin Motors. Curr Biol 2017; 27:2810-2820.e6. [PMID: 28918951 PMCID: PMC5909953 DOI: 10.1016/j.cub.2017.08.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/30/2017] [Accepted: 08/09/2017] [Indexed: 11/20/2022]
Abstract
During cell division, the mitotic kinesin-5 Eg5 generates most of the force required to separate centrosomes during spindle assembly. However, Kif15, another mitotic kinesin, can replace Eg5 function, permitting mammalian cells to acquire resistance to Eg5 poisons. Unlike Eg5, the mechanism by which Kif15 generates centrosome separation forces is unknown. Here we investigated the mechanical properties and force generation capacity of Kif15 at the single-molecule level using optical tweezers. We found that the non-motor microtubule-binding tail domain interacts with the microtubule's E-hook tail with a rupture force higher than the stall force of the motor. This allows Kif15 dimers to productively and efficiently generate forces that could potentially slide microtubules apart. Using an in vitro optical trapping and fluorescence assay, we found that Kif15 slides anti-parallel microtubules apart with gradual force buildup while parallel microtubule bundles remain stationary with a small amount of antagonizing force generated. A stochastic simulation shows the essential role of Kif15's tail domain for load storage within the Kif15-microtubule system. These results suggest a mechanism for how Kif15 rescues bipolar spindle assembly.
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Affiliation(s)
- Dana N Reinemann
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Emma G Sturgill
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Dibyendu Kumar Das
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Miriam Steiner Degen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Zsuzsanna Vörös
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Wonmuk Hwang
- Departments of Biomedical Engineering and Materials Science and Engineering, Texas A&M University, College Station, TX 77843, USA; School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, South Korea
| | - Ryoma Ohi
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Cell and Developmental Biology and LSI, University of Michigan School of Medicine, Ann Arbor, MI 48109-2216, USA.
| | - Matthew J Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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89
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Sampson J, O'Regan L, Dyer MJS, Bayliss R, Fry AM. Hsp72 and Nek6 Cooperate to Cluster Amplified Centrosomes in Cancer Cells. Cancer Res 2017; 77:4785-4796. [PMID: 28720575 DOI: 10.1158/0008-5472.can-16-3233] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 04/28/2017] [Accepted: 07/12/2017] [Indexed: 11/16/2022]
Abstract
Cancer cells frequently possess extra amplified centrosomes clustered into two poles whose pseudo-bipolar spindles exhibit reduced fidelity of chromosome segregation and promote genetic instability. Inhibition of centrosome clustering triggers multipolar spindle formation and mitotic catastrophe, offering an attractive therapeutic approach to selectively kill cells with amplified centrosomes. However, mechanisms of centrosome clustering remain poorly understood. Here, we identify a new pathway that acts through NIMA-related kinase 6 (Nek6) and Hsp72 to promote centrosome clustering. Nek6, as well as its upstream activators polo-like kinase 1 and Aurora-A, targeted Hsp72 to the poles of cells with amplified centrosomes. Unlike some centrosome declustering agents, blocking Hsp72 or Nek6 function did not induce formation of acentrosomal poles, meaning that multipolar spindles were observable only in cells with amplified centrosomes. Inhibition of Hsp72 in acute lymphoblastic leukemia cells resulted in increased multipolar spindle frequency that correlated with centrosome amplification, while loss of Hsp72 or Nek6 function in noncancer-derived cells disturbs neither spindle formation nor mitotic progression. Hence, the Nek6-Hsp72 module represents a novel actionable pathway for selective targeting of cancer cells with amplified centrosomes. Cancer Res; 77(18); 4785-96. ©2017 AACR.
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Affiliation(s)
- Josephina Sampson
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Laura O'Regan
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom
| | - Martin J S Dyer
- Ernest and Helen Scott Haematological Research Institute, University of Leicester, Leicester, United Kingdom
| | - Richard Bayliss
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Andrew M Fry
- Department of Molecular and Cell Biology, University of Leicester, Leicester, United Kingdom.
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90
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Schellhaus AK, Moreno-Andrés D, Chugh M, Yokoyama H, Moschopoulou A, De S, Bono F, Hipp K, Schäffer E, Antonin W. Developmentally Regulated GTP binding protein 1 (DRG1) controls microtubule dynamics. Sci Rep 2017; 7:9996. [PMID: 28855639 PMCID: PMC5577222 DOI: 10.1038/s41598-017-10088-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 08/03/2017] [Indexed: 11/15/2022] Open
Abstract
The mitotic spindle, essential for segregating the sister chromatids into the two evolving daughter cells, is composed of highly dynamic cytoskeletal filaments, the microtubules. The dynamics of microtubules are regulated by numerous microtubule associated proteins. We identify here Developmentally regulated GTP binding protein 1 (DRG1) as a microtubule binding protein with diverse microtubule-associated functions. In vitro, DRG1 can diffuse on microtubules, promote their polymerization, drive microtubule formation into bundles, and stabilize microtubules. HeLa cells with reduced DRG1 levels show delayed progression from prophase to anaphase because spindle formation is slowed down. To perform its microtubule-associated functions, DRG1, although being a GTPase, does not require GTP hydrolysis. However, all domains are required as truncated versions show none of the mentioned activities besides microtubule binding.
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Affiliation(s)
- Anna Katharina Schellhaus
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076, Tübingen, Germany.,Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, 52074, Aachen, Germany
| | - Daniel Moreno-Andrés
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076, Tübingen, Germany.,Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, 52074, Aachen, Germany
| | - Mayank Chugh
- Cellular Nanoscience, Center for Plant Molecular Biology (ZMBP), University of Tübingen, 72076, Tübingen, Germany
| | - Hideki Yokoyama
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076, Tübingen, Germany.,Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, 52074, Aachen, Germany
| | - Athina Moschopoulou
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076, Tübingen, Germany
| | - Suman De
- Cellular Nanoscience, Center for Plant Molecular Biology (ZMBP), University of Tübingen, 72076, Tübingen, Germany
| | - Fulvia Bono
- Max Planck Institute for Developmental Biology, Spemannstraße 35, 72076, Tübingen, Germany
| | - Katharina Hipp
- Max Planck Institute for Developmental Biology, Spemannstraße 35, 72076, Tübingen, Germany
| | - Erik Schäffer
- Cellular Nanoscience, Center for Plant Molecular Biology (ZMBP), University of Tübingen, 72076, Tübingen, Germany
| | - Wolfram Antonin
- Friedrich Miescher Laboratory of the Max Planck Society, Spemannstraße 39, 72076, Tübingen, Germany. .,Institute of Biochemistry and Molecular Cell Biology, Medical School, RWTH Aachen University, 52074, Aachen, Germany.
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91
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Howes SC, Geyer EA, LaFrance B, Zhang R, Kellogg EH, Westermann S, Rice LM, Nogales E. Structural differences between yeast and mammalian microtubules revealed by cryo-EM. J Cell Biol 2017; 216:2669-2677. [PMID: 28652389 PMCID: PMC5584162 DOI: 10.1083/jcb.201612195] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 03/31/2017] [Accepted: 05/30/2017] [Indexed: 01/03/2023] Open
Abstract
Yeast MTs do not appear to undergo the lattice compaction seen in mammalian MTs upon GTP hydrolysis. Binding of the +TIP Bim1, both between and within αβ-tubulin dimers, causes compaction of yeast MTs and their rapid disassembly. Microtubules are polymers of αβ-tubulin heterodimers essential for all eukaryotes. Despite sequence conservation, there are significant structural differences between microtubules assembled in vitro from mammalian or budding yeast tubulin. Yeast MTs were not observed to undergo compaction at the interdimer interface as seen for mammalian microtubules upon GTP hydrolysis. Lack of compaction might reflect slower GTP hydrolysis or a different degree of allosteric coupling in the lattice. The microtubule plus end–tracking protein Bim1 binds yeast microtubules both between αβ-tubulin heterodimers, as seen for other organisms, and within tubulin dimers, but binds mammalian tubulin only at interdimer contacts. At the concentrations used in cryo-electron microscopy, Bim1 causes the compaction of yeast microtubules and induces their rapid disassembly. Our studies demonstrate structural differences between yeast and mammalian microtubules that likely underlie their differing polymerization dynamics. These differences may reflect adaptations to the demands of different cell size or range of physiological growth temperatures.
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Affiliation(s)
- Stuart C Howes
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA
| | - Elisabeth A Geyer
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Benjamin LaFrance
- Molecular and Cell Biology Graduate Program, University of California, Berkeley, Berkeley, CA
| | - Rui Zhang
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Elizabeth H Kellogg
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Stefan Westermann
- Department of Molecular Genetics, Center for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Luke M Rice
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX.,Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Eva Nogales
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA .,Department of Molecular Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA
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92
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Mooney P, Sulerud T, Pelletier J, Dilsaver M, Tomschik M, Geisler C, Gatlin JC. Tau-based fluorescent protein fusions to visualize microtubules. Cytoskeleton (Hoboken) 2017; 74:221-232. [PMID: 28407416 PMCID: PMC5592782 DOI: 10.1002/cm.21368] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 04/03/2017] [Accepted: 04/10/2017] [Indexed: 01/10/2023]
Abstract
The ability to visualize cytoskeletal proteins and their dynamics in living cells has been critically important in advancing our understanding of numerous cellular processes, including actin- and microtubule (MT)-dependent phenomena such as cell motility, cell division, and mitosis. Here, we describe a novel set of fluorescent protein (FP) fusions designed specifically to visualize MTs in living systems using fluorescence microscopy. Each fusion contains a FP module linked in frame to a modified phospho-deficient version of the MT-binding domain of Tau (mTMBD). We found that expressed and purified constructs containing a single mTMBD decorated Xenopus egg extract spindles more homogenously than similar constructs containing the MT-binding domain of Ensconsin, suggesting that the binding affinity of mTMBD is minimally affected by localized signaling gradients generated during mitosis. Furthermore, MT dynamics were not grossly perturbed by the presence of Tau-based FP fusions. Interestingly, the addition of a second mTMBD to the opposite terminus of our construct caused dramatic changes to the spatial localization of probes within spindles. These results support the use of Tau-based FP fusions as minimally perturbing tools to accurately visualize MTs in living systems.
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Affiliation(s)
- Paul Mooney
- Department of Molecular Biology, University of Wyoming, Laramie, WY,
82071, USA
- Molecular & Cellular Life Sciences Program, University of
Wyoming, Laramie, WY, 82071, USA
- Cell Organization and Division Group, Marine Biological
Laboratories, Woods Hole, MA, 02543, USA
| | - Taylor Sulerud
- Department of Molecular Biology, University of Wyoming, Laramie, WY,
82071, USA
- Molecular & Cellular Life Sciences Program, University of
Wyoming, Laramie, WY, 82071, USA
- Cell Organization and Division Group, Marine Biological
Laboratories, Woods Hole, MA, 02543, USA
| | - James Pelletier
- Cell Organization and Division Group, Marine Biological
Laboratories, Woods Hole, MA, 02543, USA
- Department of Systems Biology, Harvard Medical School, Boston, MA,
02115, USA
| | - Matthew Dilsaver
- Department of Molecular Biology, University of Wyoming, Laramie, WY,
82071, USA
| | - Miroslav Tomschik
- Department of Molecular Biology, University of Wyoming, Laramie, WY,
82071, USA
| | | | - Jesse C. Gatlin
- Department of Molecular Biology, University of Wyoming, Laramie, WY,
82071, USA
- Molecular & Cellular Life Sciences Program, University of
Wyoming, Laramie, WY, 82071, USA
- Cell Organization and Division Group, Marine Biological
Laboratories, Woods Hole, MA, 02543, USA
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93
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Inner centromere localization of the CPC maintains centromere cohesion and allows mitotic checkpoint silencing. Nat Commun 2017; 8:15542. [PMID: 28561035 PMCID: PMC5460030 DOI: 10.1038/ncomms15542] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/05/2017] [Indexed: 12/18/2022] Open
Abstract
Faithful chromosome segregation during mitosis requires that the kinetochores of all sister chromatids become stably connected to microtubules derived from opposite spindle poles. How stable chromosome bi-orientation is accomplished and coordinated with anaphase onset remains incompletely understood. Here we show that stable chromosome bi-orientation requires inner centromere localization of the non-enzymatic subunits of the chromosomal passenger complex (CPC) to maintain centromeric cohesion. Precise inner centromere localization of the CPC appears less relevant for Aurora B-dependent resolution of erroneous kinetochore-microtubule (KT-MT) attachments and for the stabilization of bi-oriented KT-MT attachments once sister chromatid cohesion is preserved via knock-down of WAPL. However, Aurora B inner centromere localization is essential for mitotic checkpoint silencing to allow spatial separation from its kinetochore substrate KNL1. Our data infer that the CPC is localized at the inner centromere to sustain centromere cohesion on bi-oriented chromosomes and to coordinate mitotic checkpoint silencing with chromosome bi-orientation.
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94
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Gigant E, Stefanutti M, Laband K, Gluszek-Kustusz A, Edwards F, Lacroix B, Maton G, Canman JC, Welburn JPI, Dumont J. Inhibition of ectopic microtubule assembly by the kinesin-13 KLP-7 prevents chromosome segregation and cytokinesis defects in oocytes. Development 2017; 144:1674-1686. [PMID: 28289130 DOI: 10.1242/dev.147504] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/07/2017] [Indexed: 01/02/2023]
Abstract
In most species, oocytes lack centrosomes. Accurate meiotic spindle assembly and chromosome segregation - essential to prevent miscarriage or developmental defects - thus occur through atypical mechanisms that are not well characterized. Using quantitative in vitro and in vivo functional assays in the C. elegans oocyte, we provide novel evidence that the kinesin-13 KLP-7 promotes destabilization of the whole cellular microtubule network. By counteracting ectopic microtubule assembly and disorganization of the microtubule network, this function is strictly required for spindle organization, chromosome segregation and cytokinesis in meiotic cells. Strikingly, when centrosome activity was experimentally reduced, the absence of KLP-7 or the mammalian kinesin-13 protein MCAK (KIF2C) also resulted in ectopic microtubule asters during mitosis in C. elegans zygotes or HeLa cells, respectively. Our results highlight the general function of kinesin-13 microtubule depolymerases in preventing ectopic, spontaneous microtubule assembly when centrosome activity is defective or absent, which would otherwise lead to spindle microtubule disorganization and aneuploidy.
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Affiliation(s)
- Emmanuelle Gigant
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Marine Stefanutti
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Kimberley Laband
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Agata Gluszek-Kustusz
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, Scotland, UK
| | - Frances Edwards
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Benjamin Lacroix
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Gilliane Maton
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Julie C Canman
- Columbia University, Department of Pathology and Cell Biology, New York, NY 10032, USA
| | - Julie P I Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, Scotland, UK
| | - Julien Dumont
- Institut Jacques Monod, CNRS, UMR 7592, University Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
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95
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Destouni A, Vermeesch JR. How can zygotes segregate entire parental genomes into distinct blastomeres? The zygote metaphase revisited. Bioessays 2017; 39. [DOI: 10.1002/bies.201600226] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Aspasia Destouni
- Laboratory of Cytogenetics and Genome Research; Center of Human Genetics; KU Leuven; Leuven Belgium
| | - Joris R. Vermeesch
- Laboratory of Cytogenetics and Genome Research; Center of Human Genetics; KU Leuven; Leuven Belgium
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96
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Pemble H, Kumar P, van Haren J, Wittmann T. GSK3-mediated CLASP2 phosphorylation modulates kinetochore dynamics. J Cell Sci 2017; 130:1404-1412. [PMID: 28232523 DOI: 10.1242/jcs.194662] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 02/20/2017] [Indexed: 02/02/2023] Open
Abstract
Error-free chromosome segregation requires dynamic control of microtubule attachment to kinetochores, but how kinetochore-microtubule interactions are spatially and temporally controlled during mitosis remains incompletely understood. In addition to the NDC80 microtubule-binding complex, other proteins with demonstrated microtubule-binding activities localize to kinetochores. One such protein is the cytoplasmic linker-associated protein 2 (CLASP2). Here, we show that global GSK3-mediated phosphorylation of the longest isoform, CLASP2α, largely abolishes CLASP2α-microtubule association in metaphase. However, it does not directly control localization of CLASP2α to kinetochores. Using dominant phosphorylation-site variants, we find that CLASP2α phosphorylation weakens kinetochore-microtubule interactions as evidenced by decreased tension between sister kinetochores. Expression of CLASP2α phosphorylation-site mutants also resulted in increased chromosome segregation defects, indicating that GSK3-mediated control of CLASP2α-microtubule interactions contributes to correct chromosome dynamics. Because of global inhibition of CLASP2α-microtubule interactions, we propose a model in which only kinetochore-bound CLASP2α is dephosphorylated, locally engaging its microtubule-binding activity.
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Affiliation(s)
- Hayley Pemble
- Department of Cell & Tissue Biology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Praveen Kumar
- Department of Cell & Tissue Biology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Jeffrey van Haren
- Department of Cell & Tissue Biology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Torsten Wittmann
- Department of Cell & Tissue Biology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
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97
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Abstract
The mitotic spindle has a crucial role in ensuring the accurate segregation of chromosomes into the two daughter cells during cell division, which is paramount for maintaining genome integrity. It is a self-organized and dynamic macromolecular structure that is constructed from microtubules, microtubule-associated proteins and motor proteins. Thirty years of research have led to the identification of centrosome-, chromatin- and microtubule-mediated microtubule nucleation pathways that each contribute to mitotic spindle assembly. Far from being redundant pathways, data are now emerging regarding how they function together to ensure the timely completion of mitosis. We are also beginning to comprehend the multiple mechanisms by which cells regulate spindle scaling. Together, this research has increased our understanding of how cells coordinate hundreds of proteins to assemble the dynamic, precise and robust structure that is the mitotic spindle.
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98
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Pan D, Klare K, Petrovic A, Take A, Walstein K, Singh P, Rondelet A, Bird AW, Musacchio A. CDK-regulated dimerization of M18BP1 on a Mis18 hexamer is necessary for CENP-A loading. eLife 2017; 6. [PMID: 28059702 PMCID: PMC5245964 DOI: 10.7554/elife.23352] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 12/19/2016] [Indexed: 01/09/2023] Open
Abstract
Centromeres are unique chromosomal loci that promote the assembly of kinetochores, macromolecular complexes that bind spindle microtubules during mitosis. In most organisms, centromeres lack defined genetic features. Rather, they are specified epigenetically by a centromere-specific histone H3 variant, CENP-A. The Mis18 complex, comprising the Mis18α:Mis18β subcomplex and M18BP1, is crucial for CENP-A homeostasis. It recruits the CENP-A-specific chaperone HJURP to centromeres and primes it for CENP-A loading. We report here that a specific arrangement of Yippee domains in a human Mis18α:Mis18β 4:2 hexamer binds two copies of M18BP1 through M18BP1’s 140 N-terminal residues. Phosphorylation by Cyclin-dependent kinase 1 (CDK1) at two conserved sites in this region destabilizes binding to Mis18α:Mis18β, limiting complex formation to the G1 phase of the cell cycle. Using an improved viral 2A peptide co-expression strategy, we demonstrate that CDK1 controls Mis18 complex recruitment to centromeres by regulating oligomerization of M18BP1 through the Mis18α:Mis18β scaffold. DOI:http://dx.doi.org/10.7554/eLife.23352.001
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Affiliation(s)
- Dongqing Pan
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Kerstin Klare
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Arsen Petrovic
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Annika Take
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Kai Walstein
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Priyanka Singh
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Arnaud Rondelet
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Alexander W Bird
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max-Planck Institute of Molecular Physiology, Dortmund, Germany.,Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
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99
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El Yakoubi W, Wassmann K. Meiotic Divisions: No Place for Gender Equality. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1002:1-17. [PMID: 28600780 DOI: 10.1007/978-3-319-57127-0_1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In multicellular organisms the fusion of two gametes with a haploid set of chromosomes leads to the formation of the zygote, the first cell of the embryo. Accurate execution of the meiotic cell division to generate a female and a male gamete is required for the generation of healthy offspring harboring the correct number of chromosomes. Unfortunately, meiosis is error prone. This has severe consequences for fertility and under certain circumstances, health of the offspring. In humans, female meiosis is extremely error prone. In this chapter we will compare male and female meiosis in humans to illustrate why and at which frequency errors occur, and describe how this affects pregnancy outcome and health of the individual. We will first introduce key notions of cell division in meiosis and how they differ from mitosis, followed by a detailed description of the events that are prone to errors during the meiotic divisions.
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Affiliation(s)
- Warif El Yakoubi
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris Seine (IBPS), UMR7622, Paris, 75252, France.,CNRS, IBPS, UMR7622 Developmental Biology Lab, Paris, 75252, France
| | - Katja Wassmann
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris Seine (IBPS), UMR7622, Paris, 75252, France. .,CNRS, IBPS, UMR7622 Developmental Biology Lab, Paris, 75252, France.
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100
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Riparbelli MG, Gottardo M, Callaini G. Parthenogenesis in Insects: The Centriole Renaissance. Results Probl Cell Differ 2017; 63:435-479. [PMID: 28779329 DOI: 10.1007/978-3-319-60855-6_19] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Building a new organism usually requires the contribution of two differently shaped haploid cells, the male and female gametes, each providing its genetic material to restore diploidy of the new born zygote. The successful execution of this process requires defined sequential steps that must be completed in space and time. Otherwise, development fails. Relevant among the earlier steps are pronuclear migration and formation of the first mitotic spindle that promote the mixing of parental chromosomes and the formation of the zygotic nucleus. A complex microtubule network ensures the proper execution of these processes. Instrumental to microtubule organization and bipolar spindle assembly is a distinct non-membranous organelle, the centrosome. Centrosome inheritance during fertilization is biparental, since both gametes provide essential components to build a functional centrosome. This model does not explain, however, centrosome formation during parthenogenetic development, a special mode of sexual reproduction in which the unfertilized egg develops without the contribution of the male gamete. Moreover, whereas fertilization is a relevant example in which the cells actively check the presence of only one centrosome, to avoid multipolar spindle formation, the development of parthenogenetic eggs is ensured, at least in insects, by the de novo assembly of multiple centrosomes.Here, we will focus our attention on the assembly of functional centrosomes following fertilization and during parthenogenetic development in insects. Parthenogenetic development in which unfertilized eggs are naturally depleted of centrosomes would provide a useful experimental system to investigate centriole assembly and duplication together with centrosome formation and maturation.
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Affiliation(s)
| | - Marco Gottardo
- Department of Life Sciences, University of Siena, Via A. Moro 2, 53100, Siena, Italy
| | - Giuliano Callaini
- Department of Life Sciences, University of Siena, Via A. Moro 2, 53100, Siena, Italy.
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