1
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Leaving no-one behind: how CENP-E facilitates chromosome alignment. Essays Biochem 2021; 64:313-324. [PMID: 32347304 PMCID: PMC7475649 DOI: 10.1042/ebc20190073] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/08/2020] [Accepted: 04/14/2020] [Indexed: 02/06/2023]
Abstract
Chromosome alignment and biorientation is essential for mitotic progression and genomic stability. Most chromosomes align at the spindle equator in a motor-independent manner. However, a subset of polar kinetochores fail to bi-orient and require a microtubule motor-based transport mechanism to move to the cell equator. Centromere Protein E (CENP-E/KIF10) is a kinesin motor from the Kinesin-7 family, which localizes to unattached kinetochores during mitosis and utilizes plus-end directed microtubule motility to slide mono-oriented chromosomes to the spindle equator. Recent work has revealed how CENP-E cooperates with chromokinesins and dynein to mediate chromosome congression and highlighted its role at aligned chromosomes. Additionally, we have gained new mechanistic insights into the targeting and regulation of CENP-E motor activity at the kinetochore. Here, we will review the function of CENP-E in chromosome congression, the pathways that contribute to CENP-E loading at the kinetochore, and how CENP-E activity is regulated during mitosis.
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2
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She ZY, Yu KW, Zhong N, Xiao Y, Wei YL, Lin Y, Li YL, Lu MH. Kinesin-7 CENP-E regulates chromosome alignment and genome stability of spermatogenic cells. Cell Death Discov 2020; 6:25. [PMID: 32351712 PMCID: PMC7171076 DOI: 10.1038/s41420-020-0261-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/04/2020] [Accepted: 04/05/2020] [Indexed: 12/22/2022] Open
Abstract
Kinesin-7 CENP-E is an essential kinetochore motor required for chromosome alignment and congression. However, the specific functions of CENP-E in the spermatogenic cells during spermatogenesis remain unknown. In this study, we find that CENP-E proteins are expressed in the spermatogonia, spermatocytes, and the elongating spermatids. CENP-E inhibition by specific inhibitor GSK923295 results in the disruption of spermatogenesis and cell cycle arrest of spermatogenic cells. Both spermatogonia and spermatocytes are arrested in metaphase and several chromosomes are not aligned at the equatorial plate. We find that CENP-E inhibition leads to chromosome misalignment, the spindle disorganization, and the formation of the aneuploidy cells. Furthermore, the inhibition of CENP-E results in the defects in the formation of spermatids, including the sperm head condensation and the sperm tail formation. We have revealed that kinesin-7 CENP-E is essential for chromosome alignment and genome stability of the spermatogenic cells.
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Affiliation(s)
- Zhen-Yu She
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350122 China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, Fujian, 350122 China
| | - Kai-Wei Yu
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350122 China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, Fujian, 350122 China
| | - Ning Zhong
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350122 China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, Fujian, 350122 China
| | - Yu Xiao
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350122 China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, Fujian, 350122 China
| | - Ya-Lan Wei
- Fujian Obstetrics and Gynecology Hospital, Fuzhou, Fujian, 350001 China
- Medical Research Center, Fujian Provincial Children’s Hospital, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, 350001 China
| | - Yang Lin
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350122 China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, Fujian, 350122 China
| | - Yue-Ling Li
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350122 China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, Fujian, 350122 China
| | - Ming-Hui Lu
- Department of Cell Biology and Genetics, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350122 China
- Key Laboratory of Stem Cell Engineering and Regenerative Medicine, Fujian Province University, Fuzhou, Fujian, 350122 China
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3
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Yu KW, Zhong N, Xiao Y, She ZY. Mechanisms of kinesin-7 CENP-E in kinetochore-microtubule capture and chromosome alignment during cell division. Biol Cell 2019; 111:143-160. [PMID: 30784092 DOI: 10.1111/boc.201800082] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 01/31/2019] [Indexed: 02/06/2023]
Abstract
Chromosome congression is essential for faithful chromosome segregation and genomic stability in cell division. Centromere-associated protein E (CENP-E), a plus-end-directed kinesin motor, is required for congression of pole-proximal chromosomes in metaphase. CENP-E accumulates at the outer plate of kinetochores and mediates the kinetochore-microtubule capture. CENP-E also transports the chromosomes along spindle microtubules towards the equatorial plate. CENP-E interacts with Bub1-related kinase, Aurora B and core kinetochore components during kinetochore-microtubule attachment. In this review, we introduce the structures and mechanochemistry of kinesin-7 CENP-E. We highlight the complicated interactions between CENP-E and partner proteins during chromosome congression. We summarise the detailed roles and mechanisms of CENP-E in mitosis and meiosis, including the kinetochore-microtubule capture, chromosome congression/alignment in metaphase and the regulation of spindle assembly checkpoint. We also shed a light on the roles of CENP-E in tumourigenesis and CENP-E's specific inhibitors.
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Affiliation(s)
- Kai-Wei Yu
- Department of Cell Biology and Genetics/Center for Cell and Developmental Biology, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Ning Zhong
- Department of Cell Biology and Genetics/Center for Cell and Developmental Biology, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Yu Xiao
- Department of Cell Biology and Genetics/Center for Cell and Developmental Biology, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
| | - Zhen-Yu She
- Department of Cell Biology and Genetics/Center for Cell and Developmental Biology, The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, Fujian, 350108, China
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4
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Resende LP, Monteiro A, Brás R, Lopes T, Sunkel CE. Aneuploidy in intestinal stem cells promotes gut dysplasia in Drosophila. J Cell Biol 2018; 217:3930-3946. [PMID: 30282810 PMCID: PMC6219720 DOI: 10.1083/jcb.201804205] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/01/2018] [Accepted: 08/31/2018] [Indexed: 12/17/2022] Open
Abstract
Aneuploidy is associated with different human diseases including cancer. However, different cell types appear to respond differently to aneuploidy, either by promoting tumorigenesis or causing cell death. We set out to study the behavior of adult Drosophila melanogaster intestinal stem cells (ISCs) after induction of chromosome missegregation either by abrogation of the spindle assembly checkpoint or through kinetochore disruption or centrosome amplification. These conditions induce moderate levels of aneuploidy in ISCs, and we find no evidence of apoptosis. Instead, we observe a significant accumulation of ISCs associated with increased stem cell proliferation and an excess of enteroendocrine cells. Moreover, aneuploidy causes up-regulation of the JNK pathway throughout the posterior midgut, and specific inhibition of JNK signaling in ISCs is sufficient to prevent dysplasia. Our findings highlight the importance of understanding the behavior of different stem cell populations to aneuploidy and how these can act as reservoirs for genomic alterations that can lead to tissue pathologies.
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Affiliation(s)
- Luís Pedro Resende
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Augusta Monteiro
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Rita Brás
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Tatiana Lopes
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Claudio E Sunkel
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
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5
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Mechanisms of Chromosome Congression during Mitosis. BIOLOGY 2017; 6:biology6010013. [PMID: 28218637 PMCID: PMC5372006 DOI: 10.3390/biology6010013] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 01/07/2017] [Accepted: 01/28/2017] [Indexed: 12/13/2022]
Abstract
Chromosome congression during prometaphase culminates with the establishment of a metaphase plate, a hallmark of mitosis in metazoans. Classical views resulting from more than 100 years of research on this topic have attempted to explain chromosome congression based on the balance between opposing pulling and/or pushing forces that reach an equilibrium near the spindle equator. However, in mammalian cells, chromosome bi-orientation and force balance at kinetochores are not required for chromosome congression, whereas the mechanisms of chromosome congression are not necessarily involved in the maintenance of chromosome alignment after congression. Thus, chromosome congression and maintenance of alignment are determined by different principles. Moreover, it is now clear that not all chromosomes use the same mechanism for congressing to the spindle equator. Those chromosomes that are favorably positioned between both poles when the nuclear envelope breaks down use the so-called "direct congression" pathway in which chromosomes align after bi-orientation and the establishment of end-on kinetochore-microtubule attachments. This favors the balanced action of kinetochore pulling forces and polar ejection forces along chromosome arms that drive chromosome oscillatory movements during and after congression. The other pathway, which we call "peripheral congression", is independent of end-on kinetochore microtubule-attachments and relies on the dominant and coordinated action of the kinetochore motors Dynein and Centromere Protein E (CENP-E) that mediate the lateral transport of peripheral chromosomes along microtubules, first towards the poles and subsequently towards the equator. How the opposite polarities of kinetochore motors are regulated in space and time to drive congression of peripheral chromosomes only now starts to be understood. This appears to be regulated by position-dependent phosphorylation of both Dynein and CENP-E and by spindle microtubule diversity by means of tubulin post-translational modifications. This so-called "tubulin code" might work as a navigation system that selectively guides kinetochore motors with opposite polarities along specific spindle microtubule populations, ultimately leading to the congression of peripheral chromosomes. We propose an integrated model of chromosome congression in mammalian cells that depends essentially on the following parameters: (1) chromosome position relative to the spindle poles after nuclear envelope breakdown; (2) establishment of stable end-on kinetochore-microtubule attachments and bi-orientation; (3) coordination between kinetochore- and arm-associated motors; and (4) spatial signatures associated with post-translational modifications of specific spindle microtubule populations. The physiological consequences of abnormal chromosome congression, as well as the therapeutic potential of inhibiting chromosome congression are also discussed.
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6
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Akera T, Watanabe Y. The spindle assembly checkpoint promotes chromosome bi-orientation: A novel Mad1 role in chromosome alignment. Cell Cycle 2016; 15:493-7. [PMID: 26752263 DOI: 10.1080/15384101.2015.1128596] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Faithful chromosome segregation relies on dynamic interactions between spindle microtubules and chromosomes. Especially, all chromosomes must be aligned at the equator of the spindle to establish bi-orientation before they start to segregate. The spindle assembly checkpoint (SAC) monitors this process, inhibiting chromosome segregation until all chromosomes achieve bi-orientation. The original concept of 'checkpoints' was proposed as an external surveillance system that does not play an active role in the process it monitors. However, accumulating evidence from recent studies suggests that SAC components do play an active role in chromosome bi-orientation. In this review, we highlight a novel Mad1 role in chromosome alignment, which is the first conserved mechanism that links the SAC and kinesin-mediated chromosome gliding.
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Affiliation(s)
- Takashi Akera
- a Laboratory of Chromosome Dynamics, Institute of Molecular Cellular Biosciences, University of Tokyo , Tokyo , Japan
| | - Yoshinori Watanabe
- a Laboratory of Chromosome Dynamics, Institute of Molecular Cellular Biosciences, University of Tokyo , Tokyo , Japan
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7
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Chen JWC, Barker AR, Wakefield JG. The Ran Pathway in Drosophila melanogaster Mitosis. Front Cell Dev Biol 2015; 3:74. [PMID: 26636083 PMCID: PMC4659922 DOI: 10.3389/fcell.2015.00074] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 11/09/2015] [Indexed: 11/29/2022] Open
Abstract
Over the last two decades, the small GTPase Ran has emerged as a central regulator of both mitosis and meiosis, particularly in the generation, maintenance, and regulation of the microtubule (MT)-based bipolar spindle. Ran-regulated pathways in mitosis bear many similarities to the well-characterized functions of Ran in nuclear transport and, as with transport, the majority of these mitotic effects are mediated through affecting the physical interaction between karyopherins and Spindle Assembly Factors (SAFs)—a loose term describing proteins or protein complexes involved in spindle assembly through promoting nucleation, stabilization, and/or depolymerization of MTs, through anchoring MTs to specific structures such as centrosomes, chromatin or kinetochores, or through sliding MTs along each other to generate the force required to achieve bipolarity. As such, the Ran-mediated pathway represents a crucial functional module within the wider spindle assembly landscape. Research into mitosis using the model organism Drosophila melanogaster has contributed substantially to our understanding of centrosome and spindle function. However, in comparison to mammalian systems, very little is known about the contribution of Ran-mediated pathways in Drosophila mitosis. This article sets out to summarize our understanding of the roles of the Ran pathway components in Drosophila mitosis, focusing on the syncytial blastoderm embryo, arguing that it can provide important insights into the conserved functions on Ran during spindle formation.
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Affiliation(s)
- Jack W C Chen
- Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | - Amy R Barker
- Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK ; Centre for Microvascular Research, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London London, UK
| | - James G Wakefield
- Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
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8
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Radford SJ, Hoang TL, Głuszek AA, Ohkura H, McKim KS. Lateral and End-On Kinetochore Attachments Are Coordinated to Achieve Bi-orientation in Drosophila Oocytes. PLoS Genet 2015; 11:e1005605. [PMID: 26473960 PMCID: PMC4608789 DOI: 10.1371/journal.pgen.1005605] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/24/2015] [Indexed: 11/21/2022] Open
Abstract
In oocytes, where centrosomes are absent, the chromosomes direct the assembly of a bipolar spindle. Interactions between chromosomes and microtubules are essential for both spindle formation and chromosome segregation, but the nature and function of these interactions is not clear. We have examined oocytes lacking two kinetochore proteins, NDC80 and SPC105R, and a centromere-associated motor protein, CENP-E, to characterize the impact of kinetochore-microtubule attachments on spindle assembly and chromosome segregation in Drosophila oocytes. We found that the initiation of spindle assembly results from chromosome-microtubule interactions that are kinetochore-independent. Stabilization of the spindle, however, depends on both central spindle and kinetochore components. This stabilization coincides with changes in kinetochore-microtubule attachments and bi-orientation of homologs. We propose that the bi-orientation process begins with the kinetochores moving laterally along central spindle microtubules towards their minus ends. This movement depends on SPC105R, can occur in the absence of NDC80, and is antagonized by plus-end directed forces from the CENP-E motor. End-on kinetochore-microtubule attachments that depend on NDC80 are required to stabilize bi-orientation of homologs. A surprising finding was that SPC105R but not NDC80 is required for co-orientation of sister centromeres at meiosis I. Together, these results demonstrate that, in oocytes, kinetochore-dependent and -independent chromosome-microtubule attachments work together to promote the accurate segregation of chromosomes. In acentrosomal oocytes, spindle assembly depends on the chromosomes. The nature of the chromosome-microtubule interactions in oocytes that organize spindle bipolarity and orientation of the homologs has been unclear. We have found that several types of functional chromosome-microtubule interactions exist in oocytes, and that each type participates in unique aspects of chromosome orientation and spindle assembly. We present here a model for chromosome-based spindle assembly and chromosome movements in oocytes that highlights the multiple and unappreciated roles played by the kinetochores and has implications for how homologous chromosomes bi-orient during meiosis.
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Affiliation(s)
- Sarah J. Radford
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Tranchau L. Hoang
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - A. Agata Głuszek
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Hiroyuki Ohkura
- The Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Kim S. McKim
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- * E-mail:
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9
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Ye AA, Deretic J, Hoel CM, Hinman AW, Cimini D, Welburn JP, Maresca TJ. Aurora A Kinase Contributes to a Pole-Based Error Correction Pathway. Curr Biol 2015; 25:1842-51. [PMID: 26166783 DOI: 10.1016/j.cub.2015.06.021] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 10/23/2022]
Abstract
Chromosome biorientation, where sister kinetochores attach to microtubules (MTs) from opposing spindle poles, is the configuration that best ensures equal partitioning of the genome during cell division. Erroneous kinetochore-MT attachments are commonplace but are often corrected prior to anaphase. Error correction, thought to be mediated primarily by the centromere-enriched Aurora B kinase (ABK), typically occurs near spindle poles; however, the relevance of this locale is unclear. Furthermore, polar ejection forces (PEFs), highest near poles, can stabilize improper attachments by pushing mal-oriented chromosome arms away from spindle poles. Hence, there is a conundrum: erroneous kinetochore-MT attachments are weakened where PEFs are most likely to strengthen them. Here, we report that Aurora A kinase (AAK) opposes the stabilizing effect of PEFs. AAK activity contributes to phosphorylation of kinetochore substrates near poles and its inhibition results in chromosome misalignment and an increased incidence of erroneous kinetochore-MT attachments. Furthermore, AAK directly phosphorylates a site in the N-terminal tail of Ndc80/Hec1 that has been implicated in reducing the affinity of the Ndc80 complex for MTs when phosphorylated. We propose that an AAK activity gradient contributes to correcting mal-oriented kinetochore-MT attachments in the vicinity of spindle poles.
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Affiliation(s)
- Anna A Ye
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA; Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Jovana Deretic
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Christopher M Hoel
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Albert W Hinman
- Department of Biological Sciences and Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Daniela Cimini
- Department of Biological Sciences and Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Julie P Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, UK
| | - Thomas J Maresca
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA; Molecular and Cellular Biology Graduate Program, University of Massachusetts Amherst, Amherst, MA 01003, USA.
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10
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Abstract
Cenp-E is a kinesin-like motor protein required for efficient end-on attachment of kinetochores to the spindle microtubules. Cenp-E immunodepletion in Xenopus mitotic extracts results in the loss of mitotic arrest and massive chromosome missegregation, whereas its depletion in mammalian cells leads to chromosome segregation defects despite the presence of a functional spindle assembly checkpoint (SAC). Cenp-meta has previously been reported to be the Drosophila homolog of vertebrate Cenp-E. In this study, we show that cenp-metaΔ mutant neuroblasts arrest in mitosis when treated with colchicine. cenp-metaΔ mutant cells display a mitotic delay. Yet, despite the persistence of the two checkpoint proteins Mad2 and BubR1 on unattached kinetochores, these cells eventually enter anaphase and give rise to highly aneuploid daughter cells. Indeed, we find that cenp-metaΔ mutant cells display a slow but continuous degradation of cyclin B, which eventually triggers the mitotic exit observed. Thus, our data provide evidence for a role of Cenp-meta in sustaining the SAC response.
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Affiliation(s)
- Thomas Rubin
- Present address: Department of Genetics and Developmental Biology, Institut Curie, 75248 Paris Cedex 05, France
| | - Roger E Karess
- CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, 75205 Paris Cedex 13, France Present address: Department of Genetics and Developmental Biology, Institut Curie, 75248 Paris Cedex 05, France
| | - Zohra Rahmani
- CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, 75205 Paris Cedex 13, France Present address: Department of Genetics and Developmental Biology, Institut Curie, 75248 Paris Cedex 05, France.
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11
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Gudimchuk N, Vitre B, Kim Y, Kiyatkin A, Cleveland DW, Ataullakhanov FI, Grishchuk EL. Kinetochore kinesin CENP-E is a processive bi-directional tracker of dynamic microtubule tips. Nat Cell Biol 2013; 15:1079-1088. [PMID: 23955301 PMCID: PMC3919686 DOI: 10.1038/ncb2831] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 07/22/2013] [Indexed: 12/15/2022]
Abstract
During vertebrate mitosis, the centromere-associated kinesin CENP-E (centromere protein E) transports misaligned chromosomes to the plus ends of spindle microtubules. Subsequently, the kinetochores that form at the centromeres establish stable associations with microtubule ends, which assemble and disassemble dynamically. Here we provide evidence that after chromosomes have congressed and bi-oriented, the CENP-E motor continues to play an active role at kinetochores, enhancing their links with dynamic microtubule ends. Using a combination of single-molecule approaches and laser trapping in vitro, we demonstrate that once reaching microtubule ends, CENP-E converts from a lateral transporter into a microtubule tip-tracker that maintains association with both assembling and disassembling microtubule tips. Computational modelling of this behaviour supports our proposal that CENP-E tip-tracks bi-directionally through a tethered motor mechanism, which relies on both the motor and tail domains of CENP-E. Our results provide a molecular framework for the contribution of CENP-E to the stability of attachments between kinetochores and dynamic microtubule ends.
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Affiliation(s)
- Nikita Gudimchuk
- Physiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Benjamin Vitre
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, Univ. of California, San Diego, La Jolla, CA, United States
| | - Yumi Kim
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, Univ. of California, San Diego, La Jolla, CA, United States
| | - Anatoly Kiyatkin
- Physiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Don W Cleveland
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, Univ. of California, San Diego, La Jolla, CA, United States
| | - Fazly I Ataullakhanov
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russian Federation.,Federal Research and Clinical Centre of Pediatric Hematology, Oncology and Immunology, Moscow, Russian Federation
| | - Ekaterina L Grishchuk
- Physiology Department, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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12
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Wan J, Subramonian D, Zhang XD. SUMOylation in control of accurate chromosome segregation during mitosis. Curr Protein Pept Sci 2013; 13:467-81. [PMID: 22812528 PMCID: PMC3474960 DOI: 10.2174/138920312802430563] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 02/26/2012] [Accepted: 06/11/2012] [Indexed: 12/15/2022]
Abstract
Posttranslational protein modification by small ubiquitin-related modifier (SUMO) has emerged as an important regulatory mechanism for chromosome segregation during mitosis. This review focuses on how SUMOylation regulates the centromere and kinetochore activities to achieve accurate chromosome segregation during mitosis. Kinetochores are assembled on the specialized chromatin domains called centromeres and serve as the sites for attaching spindle microtubule to segregate sister chromatids to daughter cells. Many proteins associated with mitotic centromeres and kinetochores have been recently found to be modified by SUMO. Although we are still at the early stage of elucidating how SUMOylation controls chromosome segregation during mitosis, a substantial progress has been achieved over the past decade. Furthermore, a major theme that has emerged from the recent studies of SUMOylation in mitosis is that both SUMO conjugation and deconjugation are critical for kinetochore assembly and disassembly. Lastly, we propose a model that SUMOylation coordinates multiple centromere and kinetochore activities to ensure accurate chromosome segregation.
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Affiliation(s)
- Jun Wan
- Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA
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13
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Abstract
To maintain tissue homeostasis, some organs are able to replace dying cells with additional proliferation of surviving cells. Such proliferation can be localized (e.g., a regeneration blastema) or diffuse (compensatory growth). The relationship between such growth and the growth that occurs during development has not been characterized in detail. Drosophila melanogaster larval imaginal discs can recover from extensive damage, producing normally sized adult organs. Here we describe a system using genetic mosaics to screen for recessive mutations that impair compensatory growth. By generating clones of cells that carry a temperature-sensitive cell-lethal mutation, we conditionally ablate patches of tissue in the imaginal disc and assess the ability of the surviving sister clones to replace the lost tissue. We have used this system together with a modified whole-genome resequencing (WGS) strategy to identify several mutations that selectively compromise compensatory growth. We find specific alleles of bunched (bun) and Ribonucleoside diphosphate reductase large subunit (RnrL) reduce compensatory growth in the imaginal disc. Other genes identified in the screen, including two alleles of Topoisomerase 3-alpha (Top3α), while also required for developmental growth, appear to have an enhanced requirement during compensatory growth. Compensatory growth occurs at a higher rate than normal growth and may therefore have features in common with some types of overgrowth. Indeed, the RnrL allele identified compromises both these types of altered growth and mammalian ribonucleotide reductase and topoisomerases are targets of anticancer drugs. Finally, the approach we describe is applicable to the study of compensatory growth in diverse tissues in Drosophila.
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14
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Przewloka MR, Venkei Z, Bolanos-Garcia VM, Debski J, Dadlez M, Glover DM. CENP-C is a structural platform for kinetochore assembly. Curr Biol 2011; 21:399-405. [PMID: 21353555 DOI: 10.1016/j.cub.2011.02.005] [Citation(s) in RCA: 212] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 01/07/2011] [Accepted: 02/03/2011] [Indexed: 01/28/2023]
Abstract
Centromeres provide a region of chromatin upon which kinetochores are assembled in mitosis. Centromeric protein C (CENP-C) is a core component of this centromeric chromatin that, when depleted, prevents the proper formation of both centromeres and kinetochores. CENP-C localizes to centromeres throughout the cell cycle via its C-terminal part, whereas its N-terminal part appears necessary for recruitment of some but not all components of the Mis12 complex of the kinetochore. We now find that all kinetochore proteins belonging to the KMN (KNL1/Spc105, the Mis12 complex, and the Ndc80 complex) network bind to the N-terminal part of Drosophila CENP-C. Moreover, we show that the Mis12 complex component Nnf1 interacts directly with CENP-C in vitro. To test whether CENP-C's N-terminal part was sufficient to recruit KMN proteins, we targeted it to the centrosome by fusing it to a domain of Plk4 kinase. The Mis12 and Ndc80 complexes and Spc105 protein were then all recruited to centrosomes at the expense of centromeres, leading to mitotic abnormalities typical of cells with defective kinetochores. Thus, the N-terminal part of Drosophila CENP-C is sufficient to recruit core kinetochore components and acts as the principal linkage between centromere and kinetochore during mitosis.
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15
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Kim Y, Holland AJ, Lan W, Cleveland DW. Aurora kinases and protein phosphatase 1 mediate chromosome congression through regulation of CENP-E. Cell 2010; 142:444-55. [PMID: 20691903 DOI: 10.1016/j.cell.2010.06.039] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 04/26/2010] [Accepted: 06/14/2010] [Indexed: 12/16/2022]
Abstract
Opposing roles of Aurora kinases and protein phosphatase 1 (PP1) during mitosis have long been suggested. Here, we demonstrate that Aurora kinases A and B phosphorylate a conserved residue on the kinetochore motor CENP-E. PP1 binds CENP-E via a motif overlapping this phosphorylation site and binding is disrupted by Aurora phosphorylation. Phosphorylation of CENP-E by the Auroras is enriched at spindle poles, disrupting binding of PP1 and reducing CENP-E's affinity for individual microtubules. This phosphorylation is required for CENP-E-mediated towing of initially polar chromosomes toward the cell center. Kinetochores on such chromosomes cannot make subsequent stable attachment to spindle microtubules when dephosphorylation of CENP-E or rebinding of PP1 to CENP-E is blocked. Thus, an Aurora/PP1 phosphorylation switch modulates CENP-E motor activity as an essential feature of chromosome congression from poles and localized PP1 delivery by CENP-E to the outer kinetochore is necessary for stable microtubule capture by those chromosomes.
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Affiliation(s)
- Yumi Kim
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
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16
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Maia AF, Feijão T, Vromans MJM, Sunkel CE, Lens SMA. Aurora B kinase cooperates with CENP-E to promote timely anaphase onset. Chromosoma 2010; 119:405-13. [PMID: 20354862 DOI: 10.1007/s00412-010-0265-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 02/04/2010] [Accepted: 02/14/2010] [Indexed: 01/06/2023]
Abstract
Error-free chromosome segregation requires that all chromosomes biorient on the mitotic spindle. The motor protein Centromere-associated protein E (CENP-E) facilitates chromosome congression by mediating the lateral sliding of sister chromatids along existing K-fibers, while the mitotic kinase Aurora B detaches kinetochore-microtubule interactions that are not bioriented. Whether these activities cooperate to promote efficient chromosome biorientation and timely anaphase onset is not known. We here show that the chromosomes that fail to congress after CENP-E depletion displayed high centromeric Aurora B kinase activity. This activity destabilized spindle pole proximal kinetochore-microtubule interactions resulting in a checkpoint-dependent mitotic delay that allowed CENP-E-independent chromosome congression, thus reducing chromosome segregation errors. This shows that Aurora B keeps the mitotic checkpoint active by destabilizing kinetochore fibers of polar chromosomes to permit chromosome congression in CENP-E-compromised cells and implies that this kinase normally prevents pole proximal syntelic attachments to allow CENP-E-mediated congression of mono-oriented chromosomes.
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Affiliation(s)
- André F Maia
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
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17
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Wainman A, Creque J, Williams B, Williams EV, Bonaccorsi S, Gatti M, Goldberg ML. Roles of the Drosophila NudE protein in kinetochore function and centrosome migration. J Cell Sci 2009; 122:1747-58. [PMID: 19417004 DOI: 10.1242/jcs.041798] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We examined the distribution of the dynein-associated protein NudE in Drosophila larval brain neuroblasts and spermatocytes, and analyzed the phenotypic consequences of a nudE null mutation. NudE can associate with kinetochores, spindles and the nuclear envelope. In nudE mutant brain mitotic cells, centrosomes are often detached from the poles. Moreover, the centrosomes of mutant primary spermatocytes do not migrate from the cell cortex to the nuclear envelope, establishing a new role for NudE. In mutant neuroblasts, chromosomes fail to congress to a tight metaphase plate, and cell division arrests because of spindle assembly checkpoint (SAC) activation. The targeting of NudE to mitotic kinetochores requires the dynein-interacting protein Lis1, and surprisingly Cenp-meta, a Drosophila CENP-E homolog. NudE is non-essential for the targeting of all mitotic kinetochore components tested. However, in the absence of NudE, the 'shedding' of proteins off the kinetochore is abrogated and the SAC cannot be turned off, implying that NudE regulates dynein function at the kinetochore.
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Affiliation(s)
- Alan Wainman
- Instituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Genetica e Biologia Molecolare, Sapienza, Università di Roma, 00185 Rome, Italy
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18
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Coelho PA, Queiroz-Machado J, Carmo AM, Moutinho-Pereira S, Maiato H, Sunkel CE. Dual role of topoisomerase II in centromere resolution and aurora B activity. PLoS Biol 2008; 6:e207. [PMID: 18752348 PMCID: PMC2525683 DOI: 10.1371/journal.pbio.0060207] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Accepted: 07/16/2008] [Indexed: 11/19/2022] Open
Abstract
Chromosome segregation requires sister chromatid resolution. Condensins are essential for this process since they organize an axial structure where topoisomerase II can work. How sister chromatid separation is coordinated with chromosome condensation and decatenation activity remains unknown. We combined four-dimensional (4D) microscopy, RNA interference (RNAi), and biochemical analyses to show that topoisomerase II plays an essential role in this process. Either depletion of topoisomerase II or exposure to specific anti-topoisomerase II inhibitors causes centromere nondisjunction, associated with syntelic chromosome attachments. However, cells degrade cohesins and timely exit mitosis after satisfying the spindle assembly checkpoint. Moreover, in topoisomerase II-depleted cells, Aurora B and INCENP fail to transfer to the central spindle in late mitosis and remain tightly associated with centromeres of nondisjoined sister chromatids. Also, in topoisomerase II-depleted cells, Aurora B shows significantly reduced kinase activity both in S2 and HeLa cells. Codepletion of BubR1 in S2 cells restores Aurora B kinase activity, and consequently, most syntelic attachments are released. Taken together, our results support that topoisomerase II ensures proper sister chromatid separation through a direct role in centromere resolution and prevents incorrect microtubule-kinetochore attachments by allowing proper activation of Aurora B kinase.
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Affiliation(s)
- Paula A Coelho
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
| | - Joana Queiroz-Machado
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
- Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Porto, Portugal
| | | | | | - Helder Maiato
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
- Laboratory of Cell and Molecular Biology, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
| | - Claudio E Sunkel
- Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
- * To whom correspondence should be addressed. E-mail:
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19
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Phosphorylation relieves autoinhibition of the kinetochore motor Cenp-E. Mol Cell 2008; 29:637-43. [PMID: 18342609 DOI: 10.1016/j.molcel.2008.01.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 11/16/2007] [Accepted: 01/08/2008] [Indexed: 12/19/2022]
Abstract
During mitosis, chromosome alignment depends on the regulated dynamics of microtubules and on motor protein activities. At the kinetochore, the interplay between microtubule-binding proteins, motors, and kinases is poorly understood. Cenp-E is a kinetochore-associated kinesin involved in chromosome congression, but the mechanism by which this is achieved is unclear. Here, we present a study of the regulation of Cenp-E motility by using purified full-length (FL) Xenopus Cenp-E protein, which demonstrates that FL Cenp-E is a genuine plus-end-directed motor. Furthermore, we find that the Cenp-E tail completely blocks the motility of Cenp-E in vitro. This is achieved through direct interaction between its motor and tail domains. Finally, we show that Cenp-E autoinhibition is reversed by MPS1- or CDK1-cyclin B-mediated phosphorylation of the Cenp-E tail. This suggests a model of dynamic control of Cenp-E motility, and hence chromosome congression, dependent upon phosphorylation at the kinetochore.
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20
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Przewloka MR, Zhang W, Costa P, Archambault V, D'Avino PP, Lilley KS, Laue ED, McAinsh AD, Glover DM. Molecular analysis of core kinetochore composition and assembly in Drosophila melanogaster. PLoS One 2007; 2:e478. [PMID: 17534428 PMCID: PMC1868777 DOI: 10.1371/journal.pone.0000478] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 05/01/2007] [Indexed: 01/10/2023] Open
Abstract
Background Kinetochores are large multiprotein complexes indispensable for proper chromosome segregation. Although Drosophila is a classical model organism for studies of chromosome segregation, little is known about the organization of its kinetochores. Methodology/Principal Findings We employed bioinformatics, proteomics and cell biology methods to identify and analyze the interaction network of Drosophila kinetochore proteins. We have shown that three Drosophila proteins highly diverged from human and yeast Ndc80, Nuf2 and Mis12 are indeed their orthologues. Affinity purification of these proteins from cultured Drosophila cells identified a further five interacting proteins with weak similarity to subunits of the SPC105/KNL-1, MIND/MIS12 and NDC80 kinetochore complexes together with known kinetochore associated proteins such as dynein/dynactin, spindle assembly checkpoint components and heterochromatin proteins. All eight kinetochore complex proteins were present at the kinetochore during mitosis and MIND/MIS12 complex proteins were also centromeric during interphase. Their down-regulation led to dramatic defects in chromosome congression/segregation frequently accompanied by mitotic spindle elongation. The systematic depletion of each individual protein allowed us to establish dependency relationships for their recruitment onto the kinetochore. This revealed the sequential recruitment of individual members of first, the MIND/MIS12 and then, NDC80 complex. Conclusions/Significance The Drosophila MIND/MIS12 and NDC80 complexes and the Spc105 protein, like their counterparts from other eukaryotic species, are essential for chromosome congression and segregation, but are highly diverged in sequence. Hierarchical dependence relationships of individual proteins regulate the assembly of Drosophila kinetochore complexes in a manner similar, but not identical, to other organisms.
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Affiliation(s)
- Marcin R. Przewloka
- Cancer Research UK, Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- * To whom correspondence should be addressed. E-mail: (MRP); (DMG)
| | - Wei Zhang
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Patricia Costa
- Cancer Research UK, Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Vincent Archambault
- Cancer Research UK, Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Pier Paolo D'Avino
- Cancer Research UK, Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Kathryn S. Lilley
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Cambridge Centre for Proteomics, University of Cambridge, Cambridge, United Kingdom
| | - Ernest D. Laue
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Andrew D. McAinsh
- Chromosome Segregation Laboratory, Marie Curie Research Institute, The Chart, Oxted, United Kingdom
| | - David M. Glover
- Cancer Research UK, Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- * To whom correspondence should be addressed. E-mail: (MRP); (DMG)
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21
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Fang XK, Huang DF, Wang ZX, Wan CL, Sun T, Xu WJ, Liu CY, Zhou P, Qiao ZD. Identification of the proteins related to cytochrome P450 induced by fenvalerate in a Trichoplusia ni cell line. Cell Biol Toxicol 2007; 23:445-57. [PMID: 17484068 DOI: 10.1007/s10565-007-9006-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Accepted: 03/07/2007] [Indexed: 10/23/2022]
Abstract
In order to reveal the metabolic reaction to the presence of fenvalerate mediated by P450 in insects, we used the trypan blue exclusion technique and 3-(4,5-dimethylthiazol)-2,5-diphenyltrazolium bromide (MTT) reduction assay to assess the vitality of Trichoplusia ni (Tn) cells treated with fenvalerate, and observed dose- and time-dependent changes in total cellular P450s. In addition, two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) were used to identify the proteins involved in the fenvalerate reaction process. Finally, the cDNA of P450 fragments was cloned and real-time RT-PCR was performed. Our data showed that at the 0-15 mumol/L challenge concentration of fenvalerate, at which the vitality of Tn cells was not affected (p > 0.05), there was a tendency toward a dose- and time-response of total cellular P450s, which peaked at the 9 h (p < 0.05) and 12 h (p < 0.01) time points following 12.5 mumol/L stimulation with fenvalerate. The 2-DE assay detected more than 1300 protein spots in each two-dimensional gel, of which 33 spots displayed significant differences. Among the changed spots, three isoforms of P450 were identified. One of the three P450 cDNA fragments (CYP4L4) was cloned and sequenced, and its expression in treated Tn cells increased significantly (p < 0.01). It was found that fenvalerate induced the expression of P450s in insect cells. This suggests that fenvalerate could be metabolized by CYP4L4 through a hydroxylation reaction in insect cells.
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Affiliation(s)
- Xin-Kui Fang
- School of Agriculture and Biology, Shanghai Jiaotong University, 800 Dongchuan Road, 200240 Shanghai, PR China
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22
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Weaver BAA, Silk AD, Montagna C, Verdier-Pinard P, Cleveland DW. Aneuploidy acts both oncogenically and as a tumor suppressor. Cancer Cell 2007; 11:25-36. [PMID: 17189716 DOI: 10.1016/j.ccr.2006.12.003] [Citation(s) in RCA: 550] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 10/26/2006] [Accepted: 12/04/2006] [Indexed: 12/22/2022]
Abstract
An abnormal chromosome number, aneuploidy, is a common characteristic of tumor cells. Boveri proposed nearly 100 years ago that aneuploidy causes tumorigenesis, but this has remained untested due to the difficulty of selectively generating aneuploidy. Cells and mice with reduced levels of the mitosis-specific, centromere-linked motor protein CENP-E are now shown to develop aneuploidy and chromosomal instability in vitro and in vivo. An increased rate of aneuploidy does drive an elevated level of spontaneous lymphomas and lung tumors in aged animals. Remarkably, however, in examples of chemically or genetically induced tumor formation, an increased rate of aneuploidy is a more effective inhibitor than initiator of tumorigenesis. These findings reveal a role of aneuploidy and chromosomal instability in preventing tumorigenesis.
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Affiliation(s)
- Beth A A Weaver
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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23
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Brust-Mascher I, Scholey JM. Mitotic spindle dynamics in Drosophila. INTERNATIONAL REVIEW OF CYTOLOGY 2007; 259:139-72. [PMID: 17425941 DOI: 10.1016/s0074-7696(06)59004-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mitosis, the process by which the replicated chromosomes are segregated equally into daughter cells, has been studied for over a century. Drosophila melanogaster is an ideal organism for this research. Drosophila embryos are well suited to image mitosis, because during cycles 10-13 nuclei divide rapidly at the surface of the embryo, but mitotic cells during larval stages and spermatocytes are also used for the study of mitosis. Drosophila can be easily maintained, many mutant stocks exist, and transgenic flies expressing mutated or fluorescently labeled proteins can be made. In addition, the genome has been completed and RNA interference can be used in Drosophila tissue culture cells. Here, we review our current understanding of spindle dynamics, looking at the experiments and quantitative modeling on which it is based. Many molecular players in the Drosophila mitotic spindle are similar to those in mammalian spindles, so findings in Drosophila can be extended to other organisms.
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Affiliation(s)
- Ingrid Brust-Mascher
- Section of Molecular and Cellular Biology, University of California at Davis, Davis, California 95616, USA
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24
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Maiato H, Hergert PJ, Moutinho-Pereira S, Dong Y, Vandenbeldt KJ, Rieder CL, McEwen BF. The ultrastructure of the kinetochore and kinetochore fiber in Drosophila somatic cells. Chromosoma 2006; 115:469-80. [PMID: 16909258 PMCID: PMC2747472 DOI: 10.1007/s00412-006-0076-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 05/23/2006] [Accepted: 06/12/2006] [Indexed: 12/17/2022]
Abstract
Drosophila melanogaster is a widely used model organism for the molecular dissection of mitosis in animals. However, despite the popularity of this system, no studies have been published on the ultrastructure of Drosophila kinetochores and kinetochore fibers (K-fibers) in somatic cells. To amend this situation, we used correlative light (LM) and electron microscopy (EM) to study kinetochores in cultured Drosophila S2 cells during metaphase, and after colchicine treatment to depolymerize all microtubules (MTs). We find that the structure of attached kinetochores in S2 cells is indistinct, consisting of an amorphous inner zone associated with a more electron-dense peripheral surface layer that is approximately 40-50 nm thick. On average, each S2 kinetochore binds 11+/-2 MTs, in contrast to the 4-6 MTs per kinetochore reported for Drosophila spermatocytes. Importantly, nearly all of the kinetochore MT plus ends terminate in the peripheral surface layer, which we argue is analogous to the outer plate in vertebrate kinetochores. Our structural observations provide important data for assessing the results of RNAi studies of mitosis, as well as for the development of mathematical modelling and computer simulation studies in Drosophila and related organisms.
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Affiliation(s)
- Helder Maiato
- Institute for Molecular and Cell Biology, Rua do Campo Alegre 823, 4150-180, Porto, Portugal.
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25
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Vanstraelen M, Inzé D, Geelen D. Mitosis-specific kinesins in Arabidopsis. TRENDS IN PLANT SCIENCE 2006; 11:167-75. [PMID: 16530461 DOI: 10.1016/j.tplants.2006.02.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Revised: 01/09/2006] [Accepted: 02/24/2006] [Indexed: 05/07/2023]
Abstract
Kinesins are a class of microtubule-associated proteins that possess a motor domain for binding to microtubules and, in general, allows movement along microtubules. In animal mitosis, they function in spindle formation, chromosome movement and in cytokinesis. In addition to the spindle, plants develop a preprophase band and a phragmoplast that might require multiple kinesins for construction and functioning. Indeed, several kinesins play a role in phragmoplast and cell plate dynamics. Surprisingly few kinesins have been associated with the spindle and the preprophase band. Analysis of expression datasets from synchronized cell cultures indicate that at least 23 kinesins are in some way implicated in mitosis-related processes. In this review, the function of kinesins in animal and plant mitoses are compared, and the divergence that originates from plant-specific aspects is highlighted.
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Affiliation(s)
- Marleen Vanstraelen
- Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, Technologiepark 927, B-9052 Gent, Belgium
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26
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Civelekoglu-Scholey G, Sharp DJ, Mogilner A, Scholey JM. Model of chromosome motility in Drosophila embryos: adaptation of a general mechanism for rapid mitosis. Biophys J 2006; 90:3966-82. [PMID: 16533843 PMCID: PMC1459506 DOI: 10.1529/biophysj.105.078691] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During mitosis, ensembles of dynamic MTs and motors exert forces that coordinate chromosome segregation. Typically, chromosomes align at the metaphase spindle equator where they oscillate along the pole-pole axis before disjoining and moving poleward during anaphase A, but spindles in different cell types display differences in MT dynamicity, in the amplitude of chromosome oscillations and in rates of chromatid-to-pole motion. Drosophila embryonic mitotic spindles, for example, display remarkably dynamic MTs, barely detectable metaphase chromosome oscillations, and a rapid rate of "flux-pacman-dependent" anaphase chromatid-to-pole motility. Here we develop a force-balance model that describes Drosophila embryo chromosome motility in terms of a balance of forces acting on kinetochores and kMTs that is generated by multiple polymer ratchets and mitotic motors coupled to tension-dependent kMT dynamics. The model shows that i), multiple MTs displaying high dynamic instability can drive steady and rapid chromosome motion; ii), chromosome motility during metaphase and anaphase A can be described by a single mechanism; iii), high kinetochore dynein activity is deployed to dampen metaphase oscillations, to augment the basic flux-pacman mechanism, and to drive rapid anaphase A; iv), modulation of the MT rescue frequency by the kinetochore-associated kinesin-13 depolymerase promotes metaphase chromosome oscillations; and v), this basic mechanism can be adapted to a broad range of spindles.
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Affiliation(s)
- G Civelekoglu-Scholey
- Laboratory of Cell and Computational Biology, Center for Genetics and Development, University of California-Davis, 1 Shields Avenue, Davis, CA 95616, USA
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27
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Goshima G, Vale RD. Cell cycle-dependent dynamics and regulation of mitotic kinesins in Drosophila S2 cells. Mol Biol Cell 2005; 16:3896-907. [PMID: 15958489 PMCID: PMC1182325 DOI: 10.1091/mbc.e05-02-0118] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Constructing a mitotic spindle requires the coordinated actions of several kinesin motor proteins. Here, we have visualized the dynamics of five green fluorescent protein (GFP)-tagged mitotic kinesins (class 5, 6, 8, 13, and 14) in live Drosophila Schneider cell line (S2), after first demonstrating that the GFP-tag does not interfere with the mitotic functions of these kinesins using an RNA interference (RNAi)-based rescue strategy. Class 8 (Klp67A) and class 14 (Ncd) kinesin are sequestered in an active form in the nucleus during interphase and engage their microtubule targets upon nuclear envelope breakdown (NEB). Relocalization of Klp67A to the cytoplasm using a nuclear export signal resulted in the disassembly of the interphase microtubule array, providing support for the hypothesis that this kinesin class possesses microtubule-destabilizing activity. The interactions of Kinesin-5 (Klp61F) and -6 (Pavarotti) with microtubules, on the other hand, are activated and inactivated by Cdc2 phosphorylation, respectively, as shown by examining localization after mutating Cdc2 consensus sites. The actions of microtubule-destabilizing kinesins (class 8 and 13 [Klp10A]) seem to be controlled by cell cycle-dependent changes in their localizations. Klp10A, concentrated on microtubule plus ends in interphase and prophase, relocalizes to centromeres and spindle poles upon NEB and remains at these sites throughout anaphase. Consistent with this localization, RNAi analysis showed that this kinesin contributes to chromosome-to-pole movement during anaphase A. Klp67A also becomes kinetochore associated upon NEB, but the majority of the population relocalizes to the central spindle by the timing of anaphase A onset, consistent with our RNAi result showing no effect of depleting this motor on anaphase A. These results reveal a diverse spectrum of regulatory mechanisms for controlling the localization and function of five mitotic kinesins at different stages of the cell cycle.
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Affiliation(s)
- Gohta Goshima
- The Howard Hughes Medical Institute and the Department of Cellular and Molecular Pharmacology, University of California-San Francisco, San Francisco, CA 94107, USA
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28
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Maiato H, Sampaio P, Sunkel CE. Microtubule-associated proteins and their essential roles during mitosis. ACTA ACUST UNITED AC 2005; 241:53-153. [PMID: 15548419 DOI: 10.1016/s0074-7696(04)41002-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Microtubules play essential roles during mitosis, including chromosome capture, congression, and segregation. In addition, microtubules are also required for successful cytokinesis. At the heart of these processes is the ability of microtubules to do work, a property that derives from their intrinsic dynamic behavior. However, if microtubule dynamics were not properly regulated, it is certain that microtubules alone could not accomplish any of these tasks. In vivo, the regulation of microtubule dynamics is the responsibility of microtubule-associated proteins. Among these, we can distinguish several classes according to their function: (1) promotion and stabilization of microtubule polymerization, (2) destabilization or severance of microtubules, (3) functioning as linkers between various structures, or (4) motility-related functions. Here we discuss how the various properties of microtubule-associated proteins can be used to assemble an efficient mitotic apparatus capable of ensuring the bona fide transmission of the genetic information in animal cells.
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Affiliation(s)
- Hélder Maiato
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
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29
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Abstract
Drosophila melanogaster is an excellent model for studying mitosis. Syncytial embryos are amenable to time-lapse imaging of hundreds of synchronously dividing spindles, allowing the quantitation of spindle and chromosome dynamics with unprecedented fidelity. Other Drosophila cell types, including neuroblasts, cultured cells, spermatocytes and oocytes, contain spindles that differ in their design, providing cells amenable to different types of experiments and allowing identification of common core mechanisms. The function of mitotic proteins can be studied using mutants, inhibitor microinjection and RNA interference (RNAi) to identify the full inventory of mitotic proteins encoded by the genome. Here, we review recent advances in understanding how ensembles of mitotic proteins coordinate spindle assembly and chromosome motion in this system.
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Affiliation(s)
- Mijung Kwon
- Department of Pediatric Oncology, The Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA
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30
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Garcia-Saez I, Yen T, Wade RH, Kozielski F. Crystal structure of the motor domain of the human kinetochore protein CENP-E. J Mol Biol 2004; 340:1107-16. [PMID: 15236970 DOI: 10.1016/j.jmb.2004.05.053] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Revised: 05/07/2004] [Accepted: 05/12/2004] [Indexed: 11/30/2022]
Abstract
The human kinetochore is a highly complex macromolecular structure that connects chromosomes to spindle microtubules (MTs) in order to facilitate accurate chromosome segregation. Centromere-associated protein E (CENP-E), a member of the kinesin superfamily, is an essential component of the kinetochore, since it is required to stabilize the attachment of chromosomes to spindle MTs, to develop tension across aligned chromosomes, to stabilize spindle poles and to satisfy the mitotic checkpoint. Here we report the 2.5A resolution crystal structure of the motor domain and linker region of human CENP-E with MgADP bound in the active site. This structure displays subtle but important differences compared to the structures of human Eg5 and conventional kinesin. Our structure reveals that the CENP-E linker region is in a "docked" position identical to that in the human plus-end directed conventional kinesin. CENP-E has many advantages as a potential anti-mitotic drug target and this crystal structure of human CENP-E will provide a starting point for high throughput virtual screening of potential inhibitors.
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Affiliation(s)
- Isabel Garcia-Saez
- Laboratoire de Microscopie Electronique Structurale, Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027 Grenoble Cedex 01, France
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31
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Abstract
In plants, as in all eukaryotes, centromeres are chromatin domains that govern the transmission of nuclear chromosomes to the next generation of cells/individuals. The DNA composition and sequence organization of centromeres has recently been elucidated for a few plant species. Although there is little sequence conservation among centromeres, they usually contain tandem repeats and retroelements. The occurrence of neocentromeres reinforces the idea that the positions of centromeres are determined epigenetically. In contrast to centromeric DNA, structural and transient kinetochoric proteins are highly conserved among eukaryotes. Candidate sequences have been identified for a dozen putative kinetochore protein homologues, and some have been localized to plant centromeres. The kinetochore protein CENH3, which substitutes histone H3 within centromeric nucleosomes, co-immunoprecipitates preferentially with centromeric sequences. The mechanism(s) of centromere assembly and the functional implication of (peri-)centromeric modifications of chromatin remain to be elucidated.
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Affiliation(s)
- Andreas Houben
- Chromosome Structure and Function Group, 06466 Gatersleben, Germany.
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32
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Goshima G, Vale RD. The roles of microtubule-based motor proteins in mitosis: comprehensive RNAi analysis in the Drosophila S2 cell line. J Cell Biol 2003; 162:1003-16. [PMID: 12975346 PMCID: PMC2172859 DOI: 10.1083/jcb.200303022] [Citation(s) in RCA: 323] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Kinesins and dyneins play important roles during cell division. Using RNA interference (RNAi) to deplete individual (or combinations of) motors followed by immunofluorescence and time-lapse microscopy, we have examined the mitotic functions of cytoplasmic dynein and all 25 kinesins in Drosophila S2 cells. We show that four kinesins are involved in bipolar spindle assembly, four kinesins are involved in metaphase chromosome alignment, dynein plays a role in the metaphase-to-anaphase transition, and one kinesin is needed for cytokinesis. Functional redundancy and alternative pathways for completing mitosis were observed for many single RNAi knockdowns, and failure to complete mitosis was observed for only three kinesins. As an example, inhibition of two microtubule-depolymerizing kinesins initially produced monopolar spindles with abnormally long microtubules, but cells eventually formed bipolar spindles by an acentrosomal pole-focusing mechanism. From our phenotypic data, we construct a model for the distinct roles of molecular motors during mitosis in a single metazoan cell type.
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Affiliation(s)
- Gohta Goshima
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94107, USA
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33
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Weaver BAA, Bonday ZQ, Putkey FR, Kops GJPL, Silk AD, Cleveland DW. Centromere-associated protein-E is essential for the mammalian mitotic checkpoint to prevent aneuploidy due to single chromosome loss. J Cell Biol 2003; 162:551-63. [PMID: 12925705 PMCID: PMC2173788 DOI: 10.1083/jcb.200303167] [Citation(s) in RCA: 194] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Centromere-associated protein-E (CENP-E) is an essential mitotic kinesin that is required for efficient, stable microtubule capture at kinetochores. It also directly binds to BubR1, a kinetochore-associated kinase implicated in the mitotic checkpoint, the major cell cycle control pathway in which unattached kinetochores prevent anaphase onset. Here, we show that single unattached kinetochores depleted of CENP-E cannot block entry into anaphase, resulting in aneuploidy in 25% of divisions in primary mouse fibroblasts in vitro and in 95% of regenerating hepatocytes in vivo. Without CENP-E, diminished levels of BubR1 are recruited to kinetochores and BubR1 kinase activity remains at basal levels. CENP-E binds to and directly stimulates the kinase activity of purified BubR1 in vitro. Thus, CENP-E is required for enhancing recruitment of its binding partner BubR1 to each unattached kinetochore and for stimulating BubR1 kinase activity, implicating it as an essential amplifier of a basal mitotic checkpoint signal.
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Affiliation(s)
- Beth A A Weaver
- Ludwig Institute for Cancer Research, 3080 CMM-East, 9500 Gilman Drive, La Jolla, CA 92093-0670, USA
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34
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Abstract
Spindle microtubules interact with mitotic chromosomes, binding to their kinetochores to generate forces that are important for accurate chromosome segregation. Motor enzymes localized both at kinetochores and spindle poles help to form the biologically significant attachments between spindle fibers and their cargo, but microtubule-associated proteins without motor activity contribute to these junctions in important ways. This review examines the molecules necessary for chromosome-microtubule interaction in a range of well-studied organisms, using biological diversity to identify the factors that are essential for organized chromosome movement. We conclude that microtubule dynamics and the proteins that control them are likely to be more important for mitosis than the current enthusiasm for motor enzymes would suggest.
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Affiliation(s)
- J Richard McIntosh
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder 80309-0347, USA.
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35
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Abstract
In creating the mitotic spindle and the contractile ring, natural selection has engineered fascinating precision machines whose movements depend upon forces generated by ensembles of cytoskeletal proteins. These machines segregate chromosomes and divide the cell with high fidelity. Current research on the mechanisms and regulation of spindle morphogenesis, chromosome motility and cytokinesis emphasizes how ensembles of dynamic cytoskeletal polymers and multiple motors cooperate to generate the forces that guide the cell through mitosis and cytokinesis.
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Affiliation(s)
- Jonathan M Scholey
- Laboratory of Cell and Computational Biology, Center for Genetics and Development, University of California, Davis, California 95616, USA.
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36
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Williams BC, Li Z, Liu S, Williams EV, Leung G, Yen TJ, Goldberg ML. Zwilch, a new component of the ZW10/ROD complex required for kinetochore functions. Mol Biol Cell 2003; 14:1379-91. [PMID: 12686595 PMCID: PMC153108 DOI: 10.1091/mbc.e02-09-0624] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The Zeste-White 10 (ZW10) and Rough Deal (ROD) proteins are part of a complex necessary for accurate chromosome segregation. This complex recruits cytoplasmic dynein to the kinetochore and participates in the spindle checkpoint. We used immunoaffinity chromatography and mass spectroscopy to identify the Drosophila proteins in this complex. We found that the complex contains an additional protein we name Zwilch. Zwilch localizes to kinetochores and kinetochore microtubules in a manner identical to ZW10 and ROD. We have also isolated a zwilch mutant, which exhibits the same mitotic phenotypes associated with zw10 and rod mutations: lagging chromosomes at anaphase and precocious sister chromatid separation upon activation of the spindle checkpoint. Zwilch's role within the context of this complex is evolutionarily conserved. The human Zwilch protein (hZwilch) coimmunoprecipitates with hZW10 and hROD from HeLa cell extracts and localizes to the kinetochores at prometaphase. Finally, we discuss immunoaffinity chromatography results that suggest the existence of a weak interaction between the ZW10/ROD/Zwilch complex and the kinesin-like kinetochore component CENP-meta.
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Affiliation(s)
- Byron C Williams
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853-2703, USA
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37
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Putkey FR, Cramer T, Morphew MK, Silk AD, Johnson RS, McIntosh JR, Cleveland DW. Unstable kinetochore-microtubule capture and chromosomal instability following deletion of CENP-E. Dev Cell 2002; 3:351-65. [PMID: 12361599 DOI: 10.1016/s1534-5807(02)00255-1] [Citation(s) in RCA: 225] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A selective disruption of the mouse CENP-E gene was generated to test how this kinetochore-associated, kinesin-like protein contributes to chromosome segregation. The removal of CENP-E in primary cells produced spindles in which some metaphase chromosomes lay juxtaposed to a spindle pole, despite the absence of microtubules stably bound to their kinetochores. Most CENP-E-free chromosomes moved to the spindle equator, but their kinetochores bound only half the normal number of microtubules. Deletion of CENP-E in embryos led to early developmental arrest. Selective deletion of CENP-E in liver revealed that tissue regeneration after chemical damage was accompanied by aberrant mitoses marked by chromosome missegregation. CENP-E is thus essential for the maintenance of chromosomal stability through efficient stabilization of microtubule capture at kinetochores.
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Affiliation(s)
- Frances R Putkey
- Ludwig Institute for Cancer Research, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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38
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Joglekar AP, Hunt AJ. A simple, mechanistic model for directional instability during mitotic chromosome movements. Biophys J 2002; 83:42-58. [PMID: 12080099 PMCID: PMC1302126 DOI: 10.1016/s0006-3495(02)75148-5] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
During mitosis, chromosomes become attached to microtubules that emanate from the two spindle poles. Thereafter, a chromosome moves along these microtubule "tracks" as it executes a series of movements that bring it to the spindle equator. After the onset of anaphase, the sister chromatids separate and move to opposite spindle poles. These movements are often characterized by "directional instability" (a series of runs with approximately constant speed, punctuated by sudden reversals in the direction of movement). To understand mitosis, it is critical to describe the physical mechanisms that underlie the coordination of the forces that drive directional instability. We propose a simple mechanistic model that describes the origin of the forces that move chromosomes and the coordination of these forces to produce directional instability. The model demonstrates that forces, speeds, and direction of motion associated with prometaphase through anaphase chromosome movements can be predicted from the molecular kinetics of interactions between dynamic microtubules and arrays of microtubule binding sites that are linked to the chromosome by compliant elements.
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Affiliation(s)
- Ajit P Joglekar
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
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39
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Abstract
Centromere function requires the proper coordination of several subfunctions, such as kinetochore assembly, sister chromatid cohesion, binding of kinetochore microtubules, orientation of sister kinetochores to opposite spindle poles, and their movement towards the spindle poles. Centromere structure appears to be organized in different, separable domains in order to accomplish these functions. Despite the conserved nature of centromere functions, the molecular genetic definition of the DNA sequences that form a centromere in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, in the fruit fly Drosophila melanogaster, and in humans has revealed little conservation at the level of centromere DNA sequences. Also at the protein level few centromere proteins are conserved in all of these four organisms and many are unique to the different organisms. The recent analysis of the centromere structure in the yeast S. pombe by electron microscopy and detailed immunofluorescence microscopy of Drosophila centromeres have brought to light striking similarities at the overall structural level between these centromeres and the human centromere. The structural organization of the centromere is generally multilayered with a heterochromatin domain and a central core/inner plate region, which harbors the outer plate structures of the kinetochore. It is becoming increasingly clear that the key factors for assembly and function of the centromere structure are the specialized histones and modified histones which are present in the centromeric heterochromatin and in the chromatin of the central core. Thus, despite the differences in the DNA sequences and the proteins that define a centromere, there is an overall structural similarity between centromeres in evolutionarily diverse eukaryotes.
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Affiliation(s)
- P Bjerling
- Karolinska Institute, Sodertorn University College, S-141 04 Huddinge, Sweden
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40
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Cassimeris L, Spittle C. Regulation of microtubule-associated proteins. INTERNATIONAL REVIEW OF CYTOLOGY 2002; 210:163-226. [PMID: 11580206 DOI: 10.1016/s0074-7696(01)10006-9] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microtubule-associated proteins (MAPs) function to regulate the assembly dynamics and organization of microtubule polymers. Upstream regulation of MAP activities is the major mechanism used by cells to modify and control microtubule assembly and organization. This review summarizes the functional activities of MAPs found in animal cells and discusses how these MAPs are regulated. Mechanisms controlling gene expression, isoform-specific expression, protein localization, phosphorylation, and degradation are discussed. Additional regulatory mechanisms include synergy or competition between MAPs and the activities of cofactors or binding partners. For each MAP it is likely that regulation in vivo reflects a composite of multiple regulatory mechanisms.
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Affiliation(s)
- L Cassimeris
- Department of Biological Sciences, Lehigh University Bethlehem, Pennsylvania 18015, USA
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41
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McEwen BF, Chan GK, Zubrowski B, Savoian MS, Sauer MT, Yen TJ. CENP-E is essential for reliable bioriented spindle attachment, but chromosome alignment can be achieved via redundant mechanisms in mammalian cells. Mol Biol Cell 2001; 12:2776-89. [PMID: 11553716 PMCID: PMC59712 DOI: 10.1091/mbc.12.9.2776] [Citation(s) in RCA: 200] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
CENP-E is a kinesin-like protein that when depleted from mammalian kinetochores leads to mitotic arrest with a mixture of aligned and unaligned chromosomes. In the present study, we used immunofluorescence, video, and electron microscopy to demonstrate that depletion of CENP-E from kinetochores via antibody microinjection reduces kinetochore microtubule binding by 23% at aligned chromosomes, and severely reduces microtubule binding at unaligned chromosomes. Disruption of CENP-E function also reduces tension across the centromere, increases the incidence of spindle pole fragmentation, and results in monooriented chromosomes approaching abnormally close to the spindle pole. Nevertheless, chromosomes show typical patterns of congression, fast poleward motion, and oscillatory motions. Furthermore, kinetochores of aligned and unaligned chromosomes exhibit normal patterns of checkpoint protein localization. These data are explained by a model in which redundant mechanisms enable kinetochore microtubule binding and checkpoint monitoring in the absence of CENP-E at kinetochores, but where reduced microtubule-binding efficiency, exacerbated by poor positioning at the spindle poles, results in chronically monooriented chromosomes and mitotic arrest. Chromosome position within the spindle appears to be a critical determinant of CENP-E function at kinetochores.
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Affiliation(s)
- B F McEwen
- Division Molecular Medicine, Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA.
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42
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Brunet S, Vernos I. Chromosome motors on the move. From motion to spindle checkpoint activity. EMBO Rep 2001; 2:669-73. [PMID: 11493594 PMCID: PMC1083995 DOI: 10.1093/embo-reports/kve158] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Spindle assembly and chromosome segregation require the concerted activities of a variety of microtubule-dependent motors. This review focuses on our current knowledge of the roles played by the chromosome-associated motors during mitosis. While some appear to function conventionally in moving chromosomes along microtubules others seem to act in different ways. For example, by docking microtubules to chromosome arms, chromatin-associated motors prevent chromosome loss and participate in spindle formation and stability. Kinetochore motors participate in the formation of stable kinetochore fibers or in the control of microtubule dynamics and are involved in spindle checkpoint activity. Chromosome-associated motors thus appear to be key molecules that function in complementary ways to ensure the accuracy of chromosome segregation.
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Affiliation(s)
- S Brunet
- Cell Biology and Biophysics Program, EMBL, Meyerhofstrasse 1, Heidelberg 69117, Germany
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43
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Affiliation(s)
- Stéphane Brunet
- Cell Biology and Biophysics Program, EMBL, Meyerhofstrasse 1 Heidelberg 69117 Germany
| | - Isabelle Vernos
- Cell Biology and Biophysics Program, EMBL, Meyerhofstrasse 1 Heidelberg 69117 Germany
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44
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Blower MD, Karpen GH. The role of Drosophila CID in kinetochore formation, cell-cycle progression and heterochromatin interactions. Nat Cell Biol 2001; 3:730-9. [PMID: 11483958 PMCID: PMC3229202 DOI: 10.1038/35087045] [Citation(s) in RCA: 280] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Centromere function requires the coordination of many processes including kinetochore assembly, sister chromatid cohesion, spindle attachment and chromosome movement. Here we show that CID, the Drosophila homologue of the CENP-A centromere-specific H3-like proteins, colocalizes with molecular-genetically defined functional centromeres in minichromosomes. Injection of CID antibodies into early embryos, as well as RNA interference in tissue-culture cells, showed that CID is required for several mitotic processes. Deconvolution fluorescence microscopy showed that CID chromatin is physically separate from proteins involved in sister cohesion (MEI-S332), centric condensation (PROD), kinetochore function (ROD, ZW10 and BUB1) and heterochromatin structure (HP1). CID localization is unaffected by mutations in mei-S332, Su(var)2-5 (HP1), prod or polo. Furthermore, the localization of POLO, CENP-meta, ROD, BUB1 and MEI-S332, but not PROD or HP1, depends on the presence of functional CID. We conclude that the centromere and flanking heterochromatin are physically and functionally separable protein domains that are required for different inheritance functions, and that CID is required for normal kinetochore formation and function, as well as cell-cycle progression.
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Affiliation(s)
- Michael D. Blower
- Molecular and Cell Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
- Department of Biology, University of California, San Diego, La Jolla, California 92037, USA
| | - Gary H. Karpen
- Molecular and Cell Biology Laboratories, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
- , Correspondence and requests for materials should be addressed to G.H.K
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45
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Abstract
The yeast Mps1p protein kinase acts in centrosome duplication and the spindle assembly checkpoint. We demonstrate here that a mouse Mps1p ortholog (esk, which we designate mMps1p) regulates centrosome duplication. Endogenous mMps1p and overexpressed GFP-mMps1p localize to centrosomes and kinetochores in mouse cells. Overexpression of GFP-mMps1p causes reduplication of centrosomes during S phase arrest. In contrast, a kinase-deficient mutant blocks centrosome duplication altogether. Control of centrosome duplication by mMps1p requires a known regulator of the process, Cdk2. Inhibition of Cdk2 prevents centrosome reduplication and destabilizes mMps1p, causing its subsequent loss from centrosomes, suggesting that Cdk2 promotes mMps1p's centrosome duplication function by regulating its stability during S phase. Thus, mMps1p, an in vitro Cdk2 substrate, regulates centrosome duplication jointly with Cdk2.
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Affiliation(s)
- H A Fisk
- MCD Biology, UCB 347, University of Colorado, Boulder, Boulder, CO 80309, USA
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46
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Miki H, Setou M, Kaneshiro K, Hirokawa N. All kinesin superfamily protein, KIF, genes in mouse and human. Proc Natl Acad Sci U S A 2001; 98:7004-11. [PMID: 11416179 PMCID: PMC34614 DOI: 10.1073/pnas.111145398] [Citation(s) in RCA: 438] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Intracellular transport is essential for morphogenesis and functioning of the cell. The kinesin superfamily proteins (KIFs) have been shown to transport membranous organelles and protein complexes in a microtubule- and ATP-dependent manner. More than 30 KIFs have been reported in mice. However, the nomenclature of KIFs has not been clearly established, resulting in various designations and redundant names for a single KIF. Here, we report the identification and classification of all KIFs in mouse and human genome transcripts. Previously unidentified murine KIFs were found by a PCR-based search. The identification of all KIFs was confirmed by a database search of the total human genome. As a result, there are a total of 45 KIFs. The nomenclature of all KIFs is presented. To understand the function of KIFs in intracellular transport in a single tissue, we focused on the brain. The expression of 38 KIFs was detected in brain tissue by Northern blotting or PCR using cDNA. The brain, mainly composed of highly differentiated and polarized cells such as neurons and glia, requires a highly complex intracellular transport system as indicated by the increased number of KIFs for their sophisticated functions. It is becoming increasingly clear that the cell uses a number of KIFs and tightly controls the direction, destination, and velocity of transportation of various important functional molecules, including mRNA. This report will set the foundation of KIF and intracellular transport research.
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Affiliation(s)
- H Miki
- Department of Cell Biology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
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47
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Abstract
In all eukaryotes, a microtubule-based structure known as the spindle is responsible for accurate chromosome segregation during cell division. Spindle assembly and function require localized regulation of microtubule dynamics and the activity of a variety of microtubule-based motor proteins. Recent work has begun to uncover the molecular mechanisms that underpin this process. Here we describe the structural and dynamic properties of the spindle, and introduce the current concepts regarding how a bipolar spindle is assembled and how it functions to segregate chromosomes.
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Affiliation(s)
- T Wittmann
- Department of Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
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48
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Sharp DJ, Rogers GC, Scholey JM. Cytoplasmic dynein is required for poleward chromosome movement during mitosis in Drosophila embryos. Nat Cell Biol 2000; 2:922-30. [PMID: 11146657 DOI: 10.1038/35046574] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The movement of chromosomes during mitosis occurs on a bipolar, microtubule-based protein machine, the mitotic spindle. It has long been proposed that poleward chromosome movements that occur during prometaphase and anaphase A are driven by the microtubule motor cytoplasmic dynein, which binds to kinetochores and transports them toward the minus ends of spindle microtubules. Here we evaluate this hypothesis using time-lapse confocal microscopy to visualize, in real time, kinetochore and chromatid movements in living Drosophila embryos in the presence and absence of specific inhibitors of cytoplasmic dynein. Our results show that dynein inhibitors disrupt the alignment of kinetochores on the metaphase spindle equator and also interfere with kinetochore- and chromatid-to-pole movements during anaphase A. Thus, dynein is essential for poleward chromosome motility throughout mitosis in Drosophila embryos.
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Affiliation(s)
- D J Sharp
- Section of Molecular and Cellular Biology, University of California-Davis, 1 Shields Avenue, Davis, California 95616, USA
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