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Montembault E, Deduyer I, Claverie MC, Bouit L, Tourasse NJ, Dupuy D, McCusker D, Royou A. Two RhoGEF isoforms with distinct localisation control furrow position during asymmetric cell division. Nat Commun 2023; 14:3209. [PMID: 37268622 DOI: 10.1038/s41467-023-38912-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 05/19/2023] [Indexed: 06/04/2023] Open
Abstract
Cytokinesis partitions cellular content between daughter cells. It relies on the formation of an acto-myosin contractile ring, whose constriction induces the ingression of the cleavage furrow between the segregated chromatids. Rho1 GTPase and its RhoGEF (Pbl) are essential for this process. However, how Rho1 is regulated to sustain furrow ingression while maintaining correct furrow position remains poorly defined. Here, we show that during asymmetric division of Drosophila neuroblasts, Rho1 is controlled by two Pbl isoforms with distinct localisation. Spindle midzone- and furrow-enriched Pbl-A focuses Rho1 at the furrow to sustain efficient ingression, while Pbl-B pan-plasma membrane localization promotes the broadening of Rho1 activity and the subsequent enrichment of myosin on the entire cortex. This enlarged zone of Rho1 activity is critical to adjust furrow position, thereby preserving correct daughter cell size asymmetry. Our work highlights how the use of isoforms with distinct localisation makes an essential process more robust.
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Affiliation(s)
- Emilie Montembault
- CNRS, UMR5095, University of Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France
- CNRS, UMR5095, University of Bordeaux, Institut de Biologie et Génétique Cellulaire, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Irène Deduyer
- CNRS, UMR5095, University of Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France
- CNRS, UMR5095, University of Bordeaux, Institut de Biologie et Génétique Cellulaire, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Marie-Charlotte Claverie
- CNRS, UMR5095, University of Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France
- CNRS, UMR5095, University of Bordeaux, Institut de Biologie et Génétique Cellulaire, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Lou Bouit
- CNRS, UMR5095, University of Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France
- CNRS, UMR5297, University of Bordeaux, 146 Rue Léo Saignat, 33076, Bordeaux, France
| | - Nicolas J Tourasse
- University of Bordeaux, INSERM, U1212, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France
| | - Denis Dupuy
- University of Bordeaux, INSERM, U1212, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France
| | - Derek McCusker
- CNRS, UMR5095, University of Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France
- CNRS, UMR5095, University of Bordeaux, Institut de Biologie et Génétique Cellulaire, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France
| | - Anne Royou
- CNRS, UMR5095, University of Bordeaux, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607, Pessac, France.
- CNRS, UMR5095, University of Bordeaux, Institut de Biologie et Génétique Cellulaire, 1 rue Camille Saint-Saëns, 33077, Bordeaux, France.
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2
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Prevo B, Cheerambathur DK, Earnshaw WC, Desai A. Kinetochore dynein is sufficient to biorient chromosomes and remodel the outer kinetochore. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.23.534015. [PMID: 36993239 PMCID: PMC10055418 DOI: 10.1101/2023.03.23.534015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Multiple microtubule-directed activities concentrate on chromosomes during mitosis to ensure their accurate distribution to daughter cells. These activities include couplers and dynamics regulators localized at the kinetochore, the specialized microtubule interface built on centromeric chromatin, as well as motor proteins recruited to kinetochores and to mitotic chromatin. Here, we describe an in vivo reconstruction approach in which the effect of removing the major microtubule-directed activities on mitotic chromosomes is compared to the selective presence of individual activities. This approach revealed that the kinetochore dynein module, comprised of the minus end-directed motor cytoplasmic dynein and its kinetochore-specific adapters, is sufficient to biorient chromosomes and to remodel outer kinetochore composition following microtubule attachment; by contrast, the kinetochore dynein module is unable to support chromosome congression. The chromosome-autonomous action of kinetochore dynein, in the absence of the other major microtubule-directed factors on chromosomes, rotates and orients a substantial proportion of chromosomes such that their sister chromatids attach to opposite spindle poles. In tight coupling with orientation, the kinetochore dynein module drives removal of outermost kinetochore components, including the dynein motor itself and spindle checkpoint activators. The removal is independent of the other major microtubule-directed activities and kinetochore-localized protein phosphatase 1, suggesting that it is intrinsic to the kinetochore dynein module. These observations indicate that the kinetochore dynein module has the ability coordinate chromosome biorientation with attachment state-sensitive remodeling of the outer kinetochore that facilitates cell cycle progression.
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Affiliation(s)
- Bram Prevo
- Ludwig Institute for Cancer Research, La Jolla, California 92093, USA
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Dhanya K Cheerambathur
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - Arshad Desai
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92093, USA
- Ludwig Institute for Cancer Research, La Jolla, California 92093, USA
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3
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Abstract
The microtubule minus-end-directed motility of cytoplasmic dynein 1 (dynein), arguably the most complex and versatile cytoskeletal motor, is harnessed for diverse functions, such as long-range organelle transport in neuronal axons and spindle assembly in dividing cells. The versatility of dynein raises a number of intriguing questions, including how is dynein recruited to its diverse cargo, how is recruitment coupled to activation of the motor, how is motility regulated to meet different requirements for force production and how does dynein coordinate its activity with that of other microtubule-associated proteins (MAPs) present on the same cargo. Here, these questions will be discussed in the context of dynein at the kinetochore, the supramolecular protein structure that connects segregating chromosomes to spindle microtubules in dividing cells. As the first kinetochore-localized MAP described, dynein has intrigued cell biologists for more than three decades. The first part of this Review summarizes current knowledge about how kinetochore dynein contributes to efficient and accurate spindle assembly, and the second part describes the underlying molecular mechanisms and highlights emerging commonalities with dynein regulation at other subcellular sites.
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Affiliation(s)
- Reto Gassmann
- Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Biologia Molecular e Celular - IBMC, Universidade do Porto, 4200-135 Porto, Portugal
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4
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Wang C, Wang Y, Liu C, Meng X, Hang Z. Kinetochore-associated protein 1 promotes the invasion and tumorigenicity of cervical cancer cells via matrix metalloproteinase-2 and matrix metalloproteinase-9. Bioengineered 2022; 13:9495-9507. [PMID: 35389773 PMCID: PMC9161993 DOI: 10.1080/21655979.2022.2061144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
Cervical cancer, a common cancer in women, has become a serious social burden. Kinetochore-associated protein 1 (KNTC1) that regulates the cell cycle by regulating mitosis is related to the malignant behavior of different types of tumors. However, its role in the development of cervical cancer remains unclear. In this study, we initially explored the role of KNTC1 in cervical cancer. KNTC1 expression and relevant information were downloaded from The Cancer Genome Atlas (TCGA) and dataset GSE63514 in the Gene Expression Omnibus (GEO) database for bioinformatics analyses. Cell proliferation was detected by cell counting kit-8 (CCK8) and colony formation assays. Wound healing and Transwell assays were used to evaluate cell migration and invasion abilities. Protein expression levels of matrix metallopeptidase 2 (MMP2) and matrix metallopeptidase 9 (MMP9) were measured by western blotting. Nude mouse models of subcutaneous xenograft tumor were constructed to analyze tumor growth in vivo. CCK8 and colony formation assay results demonstrated that the proliferation rate of SiHa and C-33A cells decreased when KNTC1 was silenced. Western blot and Transwell assays indicated that KNTC1 knockdown weakened the invasion and migration abilities of SiHa and C-33A cells and decreased the expression of MMP-2 and MMP-9. In-vivo experiments suggested that the inhibition of KNTC1 reduced tumor growth. Taken together, our study showed that KNTC1 plays an important role in cervical cancer. Further, we verified the promotional effect of KNTC1 on cervical cancer through in-vivo and in-vitro experiments and speculated that KNTC1 might mediate tumor invasion via MMP9 and MMP2.
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Affiliation(s)
- Caimei Wang
- Obstetrics and Gynecology, Yulin Second Hospital, Yulin, Shaanxi Province, China
| | - Yiyuan Wang
- Department of Stomatology, The Second Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, Shaanxi Province, China.,School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Congrong Liu
- Obstetrics and Gynecology, Yulin Second Hospital, Yulin, Shaanxi Province, China
| | - Xiaoyu Meng
- Obstetrics and Gynecology, Yulin Second Hospital, Yulin, Shaanxi Province, China
| | - Zhongxia Hang
- Obstetrics and Gynecology, Yulin Second Hospital, Yulin, Shaanxi Province, China
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5
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Barbosa J, Sunkel CE, Conde C. The Role of Mitotic Kinases and the RZZ Complex in Kinetochore-Microtubule Attachments: Doing the Right Link. Front Cell Dev Biol 2022; 10:787294. [PMID: 35155423 PMCID: PMC8832123 DOI: 10.3389/fcell.2022.787294] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/13/2022] [Indexed: 12/31/2022] Open
Abstract
During mitosis, the interaction of kinetochores (KTs) with microtubules (MTs) drives chromosome congression to the spindle equator and supports the segregation of sister chromatids. Faithful genome partition critically relies on the ability of chromosomes to establish and maintain proper amphitelic end-on attachments, a configuration in which sister KTs are connected to robust MT fibers emanating from opposite spindle poles. Because the capture of spindle MTs by KTs is error prone, cells use mechanisms that sense and correct inaccurate KT-MT interactions before committing to segregate sister chromatids in anaphase. If left unresolved, these errors can result in the unequal distribution of chromosomes and lead to aneuploidy, a hallmark of cancer. In this review, we provide an overview of the molecular strategies that monitor the formation and fine-tuning of KT-MT attachments. We describe the complex network of proteins that operates at the KT-MT interface and discuss how AURORA B and PLK1 coordinate several concurrent events so that the stability of KT-MT attachments is precisely modulated throughout mitotic progression. We also outline updated knowledge on how the RZZ complex is regulated to ensure the formation of end-on attachments and the fidelity of mitosis.
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Affiliation(s)
- João Barbosa
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Claudio E. Sunkel
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Carlos Conde
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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6
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Hara M, Fukagawa T. Dynamics of kinetochore structure and its regulations during mitotic progression. Cell Mol Life Sci 2020; 77:2981-2995. [PMID: 32052088 PMCID: PMC11104943 DOI: 10.1007/s00018-020-03472-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 12/27/2019] [Accepted: 01/28/2020] [Indexed: 12/12/2022]
Abstract
Faithful chromosome segregation during mitosis in eukaryotes requires attachment of the kinetochore, a large protein complex assembled on the centromere of each chromosome, to the spindle microtubules. The kinetochore is a structural interface for the microtubule attachment and provides molecular surveillance mechanisms that monitor and ensure the precise microtubule attachment as well, including error correction and spindle assembly checkpoint. During mitotic progression, the kinetochore undergoes dynamic morphological changes that are observable through electron microscopy as well as through fluorescence microscopy. These structural changes might be associated with the kinetochore function. In this review, we summarize how the dynamics of kinetochore morphology are associated with its functions and discuss recent findings on the switching of protein interaction networks in the kinetochore during cell cycle progression.
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Affiliation(s)
- Masatoshi Hara
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.
| | - Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.
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7
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Barbosa J, Martins T, Bange T, Tao L, Conde C, Sunkel C. Polo regulates Spindly to prevent premature stabilization of kinetochore-microtubule attachments. EMBO J 2020; 39:e100789. [PMID: 31849090 PMCID: PMC6960449 DOI: 10.15252/embj.2018100789] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 12/13/2022] Open
Abstract
Accurate chromosome segregation in mitosis requires sister kinetochores to bind to microtubules from opposite spindle poles. The stability of kinetochore-microtubule attachments is fine-tuned to prevent or correct erroneous attachments while preserving amphitelic interactions. Polo kinase has been implicated in both stabilizing and destabilizing kinetochore-microtubule attachments. However, the mechanism underlying Polo-destabilizing activity remains elusive. Here, resorting to an RNAi screen in Drosophila for suppressors of a constitutively active Polo mutant, we identified a strong genetic interaction between Polo and the Rod-ZW10-Zwilch (RZZ) complex, whose kinetochore accumulation has been shown to antagonize microtubule stability. We find that Polo phosphorylates Spindly and impairs its ability to bind to Zwilch. This precludes dynein-mediated removal of the RZZ from kinetochores and consequently delays the formation of stable end-on attachments. We propose that high Polo-kinase activity following mitotic entry directs the RZZ complex to minimize premature stabilization of erroneous attachments, whereas a decrease in active Polo in later mitotic stages allows the formation of stable amphitelic spindle attachments. Our findings demonstrate that Polo tightly regulates the RZZ-Spindly-dynein module during mitosis to ensure the fidelity of chromosome segregation.
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Affiliation(s)
- João Barbosa
- IBMC—Instituto de Biologia Molecular e CelularUniversidade do PortoPortoPortugal
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do PortoPortoPortugal
| | | | - Tanja Bange
- MPI für molekulare PhysiologieDortmundGermany
| | - Li Tao
- Department of BiologyUniversity of HawaiiHiloHIUSA
| | - Carlos Conde
- IBMC—Instituto de Biologia Molecular e CelularUniversidade do PortoPortoPortugal
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do PortoPortoPortugal
| | - Claudio Sunkel
- IBMC—Instituto de Biologia Molecular e CelularUniversidade do PortoPortoPortugal
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do PortoPortoPortugal
- ICBAS—Instituto de Ciência Biomédica de Abel SalazarUniversidade do PortoPortoPortugal
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8
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Pauleau AL, Bergner A, Kajtez J, Erhardt S. The checkpoint protein Zw10 connects CAL1-dependent CENP-A centromeric loading and mitosis duration in Drosophila cells. PLoS Genet 2019; 15:e1008380. [PMID: 31553715 PMCID: PMC6779278 DOI: 10.1371/journal.pgen.1008380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 10/07/2019] [Accepted: 08/22/2019] [Indexed: 11/18/2022] Open
Abstract
A defining feature of centromeres is the presence of the histone H3 variant CENP-A that replaces H3 in a subset of centromeric nucleosomes. In Drosophila cultured cells CENP-A deposition at centromeres takes place during the metaphase stage of the cell cycle and strictly depends on the presence of its specific chaperone CAL1. How CENP-A loading is restricted to mitosis is unknown. We found that overexpression of CAL1 is associated with increased CENP-A levels at centromeres and uncouples CENP-A loading from mitosis. Moreover, CENP-A levels inversely correlate with mitosis duration suggesting crosstalk of CENP-A loading with the regulatory machinery of mitosis. Mitosis length is influenced by the spindle assembly checkpoint (SAC), and we found that CAL1 interacts with the SAC protein and RZZ complex component Zw10 and thus constitutes the anchor for the recruitment of RZZ. Therefore, CAL1 controls CENP-A incorporation at centromeres both quantitatively and temporally, connecting it to the SAC to ensure mitotic fidelity. Segregation of DNA during mitosis is a highly regulated process necessary to ensure the faithful transmission of genetic material to new daughter cells. Centromeric chromatin, which is defined by the presence of the histone H3 variant CENP-A, mediates the interaction of chromosomes with the spindle apparatus. In most organisms, CENP-A incorporation into centromeric chromatin is uncoupled from DNA replication and depends on specialized loading mechanisms and chaperones. In Drosophila cells, CENP-A loading takes place during mitosis and is mediated by its loading factor CAL1. We show that CAL1 controls the amount as well as the timing of CENP-A incorporation into centromeric chromatin. Moreover, CENP-A loading inversely correlates with the duration of mitosis. Mitosis length is influenced by the spindle assembly checkpoint, which ensures that all centromeres are attached correctly to the microtubule spindle. We identified the checkpoint protein and RZZ component Zw10 as a new interactor of CAL1. This interaction establishes a connection between CENP-A loading and mitosis control. We hypothesize that this crosstalk between CENP-A loading and spindle assembly checkpoint ensures that mitosis does not proceed until a sufficient amount of CENP-A is incorporated, thereby safeguarding centromere function and chromosome segregation.
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Affiliation(s)
- Anne-Laure Pauleau
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
- DKFZ-ZMBH-Alliance, Heidelberg, Germany
- CellNetworks Excellence Cluster, Heidelberg University, Heidelberg, Germany
| | - Andrea Bergner
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
- DKFZ-ZMBH-Alliance, Heidelberg, Germany
- CellNetworks Excellence Cluster, Heidelberg University, Heidelberg, Germany
| | - Janko Kajtez
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Sylvia Erhardt
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
- DKFZ-ZMBH-Alliance, Heidelberg, Germany
- CellNetworks Excellence Cluster, Heidelberg University, Heidelberg, Germany
- * E-mail:
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9
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Abstract
Mistakes in the process of cell division can lead to the loss, gain or rearrangement of chromosomes. Significant chromosomal abnormalities are usually lethal to the cells and cause spontaneous miscarriages. However, in some cases, defects in the spindle assembly checkpoint lead to severe diseases, such as cancer and birth and development defects, including Down's syndrome. The timely and accurate control of chromosome segregation in mitosis relies on the spindle assembly checkpoint (SAC), an evolutionary conserved, self-regulated signalling system present in higher organisms. The spindle assembly checkpoint is orchestrated by dynamic interactions between spindle microtubules and the kinetochore , a multiprotein complex that constitutes the site for attachment of chromosomes to microtubule polymers to pull sister chromatids apart during cell division. This chapter discusses the current molecular understanding of the essential, highly dynamic molecular interactions underpinning spindle assembly checkpoint signalling and how the complex choreography of interactions can be coordinated in time and space to finely regulate the process. The potential of targeting this signalling pathway to interfere with the abnormal segregation of chromosomes, which occurs in diverse malignancies and the new opportunities that recent technological developments are opening up for a deeper understanding of the spindle assembly checkpoint are also discussed.
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Affiliation(s)
- Victor M Bolanos-Garcia
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK.
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10
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Requirement of the Dynein-Adaptor Spindly for Mitotic and Post-Mitotic Functions in Drosophila. J Dev Biol 2018; 6:jdb6020009. [PMID: 29615558 PMCID: PMC6027351 DOI: 10.3390/jdb6020009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/20/2018] [Accepted: 03/27/2018] [Indexed: 11/17/2022] Open
Abstract
Spindly was originally identified as a specific regulator of Dynein activity at the kinetochore. In early prometaphase, Spindly recruits the Dynein/Dynactin complex, promoting the establishment of stable kinetochore-microtubule interactions and progression into anaphase. While details of Spindly function in mitosis have been worked out in cultured human cells and in the C. elegans zygote, the function of Spindly within the context of an organism has not yet been addressed. Here, we present loss- and gain-of-function studies of Spindly using transgenic RNAi in Drosophila. Knock-down of Spindly in the female germ line results in mitotic arrest during embryonic cleavage divisions. We investigated the requirements of Spindly protein domains for its localisation and function, and found that the carboxy-terminal region controls Spindly localisation in a cell-type specific manner. Overexpression of Spindly in the female germ line is embryonic lethal and results in altered egg morphology. To determine whether Spindly plays a role in post-mitotic cells, we altered Spindly protein levels in migrating cells and found that ovarian border cell migration is sensitive to the levels of Spindly protein. Our study uncovers novel functions of Spindly and a differential, functional requirement for its carboxy-terminal region in Drosophila.
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11
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Simões PA, Celestino R, Carvalho AX, Gassmann R. NudE regulates dynein at kinetochores but is dispensable for other dynein functions in the C. elegans early embryo. J Cell Sci 2018; 131:jcs.212159. [PMID: 29192061 PMCID: PMC5818066 DOI: 10.1242/jcs.212159] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 11/27/2017] [Indexed: 12/12/2022] Open
Abstract
In mitosis, the molecular motor dynein is recruited to kinetochores by the Rod-Zw10-Zwilch complex (RZZ) and Spindly to control spindle assembly checkpoint (SAC) signaling and microtubule attachment. How the ubiquitous dynein co-factors Lis1 and NudE contribute to these functions remains poorly understood. Here, we show that the C. elegans NudE homolog NUD-2 is dispensable for dynein- and LIS-1-dependent mitotic spindle assembly in the zygote. This facilitates functional characterization of kinetochore-localized NUD-2, which is recruited by the CENP-F-like proteins HCP-1 and HCP-2 independently of RZZ-Spindly and dynein-LIS-1. Kinetochore dynein levels are reduced in Δnud-2 embryos, and, as occurs upon RZZ inhibition, loss of NUD-2 delays the formation of load-bearing kinetochore-microtubule attachments and causes chromatin bridges in anaphase. Survival of Δnud-2 embryos requires a functional SAC, and kinetochores without NUD-2 recruit an excess of SAC proteins. Consistent with this, SAC signaling in early Δnud-2 embryos extends mitotic duration and prevents high rates of chromosome mis-segregation. Our results reveal that both NUD-2 and RZZ-Spindly are essential for dynein function at kinetochores, and that the gain in SAC strength during early embryonic development is relevant under conditions that mildly perturb mitosis.
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Affiliation(s)
- Patrícia A Simões
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Ricardo Celestino
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana X Carvalho
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Reto Gassmann
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal .,Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
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12
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Gama JB, Pereira C, Simões PA, Celestino R, Reis RM, Barbosa DJ, Pires HR, Carvalho C, Amorim J, Carvalho AX, Cheerambathur DK, Gassmann R. Molecular mechanism of dynein recruitment to kinetochores by the Rod-Zw10-Zwilch complex and Spindly. J Cell Biol 2017; 216:943-960. [PMID: 28320824 PMCID: PMC5379953 DOI: 10.1083/jcb.201610108] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 01/03/2017] [Accepted: 01/23/2017] [Indexed: 01/02/2023] Open
Abstract
The dynein motor is recruited to the kinetochore to capture spindle microtubules and control the spindle assembly checkpoint. Gama et al. reveal the molecular mechanism of how the Rod–Zw10–Zwilch complex and Spindly mediate dynein recruitment in Caenorhabditis elegans and human cells. The molecular motor dynein concentrates at the kinetochore region of mitotic chromosomes in animals to accelerate spindle microtubule capture and to control spindle checkpoint signaling. In this study, we describe the molecular mechanism used by the Rod–Zw10–Zwilch complex and the adaptor Spindly to recruit dynein to kinetochores in Caenorhabditis elegans embryos and human cells. We show that Rod’s N-terminal β-propeller and the associated Zwilch subunit bind Spindly’s C-terminal domain, and we identify a specific Zwilch mutant that abrogates Spindly and dynein recruitment in vivo and Spindly binding to a Rod β-propeller–Zwilch complex in vitro. Spindly’s N-terminal coiled-coil uses distinct motifs to bind dynein light intermediate chain and the pointed-end complex of dynactin. Mutations in these motifs inhibit assembly of a dynein–dynactin–Spindly complex, and a null mutant of the dynactin pointed-end subunit p27 prevents kinetochore recruitment of dynein–dynactin without affecting other mitotic functions of the motor. Conservation of Spindly-like motifs in adaptors involved in intracellular transport suggests a common mechanism for linking dynein to cargo.
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Affiliation(s)
- José B Gama
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Cláudia Pereira
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Patrícia A Simões
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ricardo Celestino
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Rita M Reis
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Daniel J Barbosa
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Helena R Pires
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Cátia Carvalho
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - João Amorim
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana X Carvalho
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Dhanya K Cheerambathur
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Reto Gassmann
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal .,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
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13
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Défachelles L, Hainline SG, Menant A, Lee LA, Karess RE. A maternal effect rough deal mutation suggests that multiple pathways regulate Drosophila RZZ kinetochore recruitment. J Cell Sci 2015; 128:1204-16. [PMID: 25616898 DOI: 10.1242/jcs.165712] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Proper kinetochore recruitment and regulation of dynein and the Mad1-Mad2 complex requires the Rod-Zw10-Zwilch (RZZ) complex. Here, we describe rod(Z3), a maternal-effect Drosophila mutation changing a single residue in the Rough Deal (Rod) subunit of RZZ. Although the RZZ complex containing this altered subunit (denoted R(Z3)ZZ) is present in early syncytial stage embryos laid by homozygous rod(Z3) mothers, it is not recruited to kinetochores. Consequently, the embryos have no spindle assembly checkpoint (SAC), and syncytial mitoses are profoundly perturbed. The polar body (residual meiotic products) cannot remain in its SAC-dependent metaphase-like state, and decondenses into chromatin. In neuroblasts of homozygous rod(Z3) larvae, R(Z3)ZZ recruitment is only partially reduced, the SAC is functional and mitosis is relatively normal. R(Z3)ZZ nevertheless behaves abnormally: it does not further accumulate on kinetochores when microtubules are depolymerized; it reduces the rate of Mad1 recruitment; and it dominantly interferes with the dynein-mediated streaming of RZZ from attached kinetochores. These results suggest that the mutated residue of rod(Z3) is required for normal RZZ kinetochore recruitment and function and, moreover, that the RZZ recruitment pathway might differ in syncytial stage embryos and post-embryonic somatic cells.
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Affiliation(s)
- Lénaïg Défachelles
- Equipe Labellisée Ligue Contre le Cancer, CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris Cedex 13 75205, France
| | - Sarah G Hainline
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA
| | - Alexandra Menant
- Equipe Labellisée Ligue Contre le Cancer, CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris Cedex 13 75205, France
| | - Laura A Lee
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA
| | - Roger E Karess
- Equipe Labellisée Ligue Contre le Cancer, CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris Cedex 13 75205, France
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14
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Tagaya M, Arasaki K, Inoue H, Kimura H. Moonlighting functions of the NRZ (mammalian Dsl1) complex. Front Cell Dev Biol 2014; 2:25. [PMID: 25364732 PMCID: PMC4206994 DOI: 10.3389/fcell.2014.00025] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/20/2014] [Indexed: 12/31/2022] Open
Abstract
The yeast Dsl1 complex, which comprises Dsl1, Tip20, and Sec39/Dsl3, has been shown to participate, as a vesicle-tethering complex, in retrograde trafficking from the Golgi apparatus to the endoplasmic reticulum. Its metazoan counterpart NRZ complex, which comprises NAG, RINT1, and ZW10, is also involved in Golgi-to-ER retrograde transport, but each component of the complex has diverse cellular functions including endosome-to-Golgi transport, cytokinesis, cell cycle checkpoint, autophagy, and mRNA decay. In this review, we summarize the current knowledge of the metazoan NRZ complex and discuss the "moonlighting" functions and intercorrelation of their subunits.
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Affiliation(s)
- Mitsuo Tagaya
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Kohei Arasaki
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Hiroki Inoue
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
| | - Hana Kimura
- Department of Molecular Life Sciences, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Hachioji, Japan
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15
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Raaijmakers JA, Medema RH. Function and regulation of dynein in mitotic chromosome segregation. Chromosoma 2014; 123:407-22. [PMID: 24871939 DOI: 10.1007/s00412-014-0468-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/08/2014] [Accepted: 05/09/2014] [Indexed: 12/23/2022]
Abstract
Cytoplasmic dynein is a large minus-end-directed microtubule motor complex, involved in many different cellular processes including intracellular trafficking, organelle positioning, and microtubule organization. Furthermore, dynein plays essential roles during cell division where it is implicated in multiple processes including centrosome separation, chromosome movements, spindle organization, spindle positioning, and mitotic checkpoint silencing. How is a single motor able to fulfill this large array of functions and how are these activities temporally and spatially regulated? The answer lies in the unique composition of the dynein motor and in the interactions it makes with multiple regulatory proteins that define the time and place where dynein becomes active. Here, we will focus on the different mitotic processes that dynein is involved in, and how its regulatory proteins act to support dynein. Although dynein is highly conserved amongst eukaryotes (with the exception of plants), there is significant variability in the cellular processes that depend on dynein in different species. In this review, we concentrate on the functions of cytoplasmic dynein in mammals but will also refer to data obtained in other model organisms that have contributed to our understanding of dynein function in higher eukaryotes.
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Affiliation(s)
- J A Raaijmakers
- Department of Cell Biology and Cancer Genomics Center, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, Netherlands
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16
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Civril F, Wehenkel A, Giorgi FM, Santaguida S, Di Fonzo A, Grigorean G, Ciccarelli FD, Musacchio A. Structural analysis of the RZZ complex reveals common ancestry with multisubunit vesicle tethering machinery. Structure 2010; 18:616-26. [PMID: 20462495 DOI: 10.1016/j.str.2010.02.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 01/22/2010] [Accepted: 02/19/2010] [Indexed: 01/31/2023]
Abstract
The RZZ complex recruits dynein to kinetochores. We investigated structure, topology, and interactions of the RZZ subunits (ROD, ZWILCH, and ZW10) in vitro, in vivo, and in silico. We identify neuroblastoma-amplified gene (NAG), a ZW10 binder, as a ROD homolog. ROD and NAG contain an N-terminal beta propeller followed by an alpha solenoid, which is the architecture of certain nucleoporins and vesicle coat subunits, suggesting a distant evolutionary relationship. ZW10 binding to ROD and NAG is mutually exclusive. The resulting ZW10 complexes (RZZ and NRZ) respectively contain ZWILCH and RINT1 as additional subunits. The X-ray structure of ZWILCH, the first for an RZZ subunit, reveals a novel fold distinct from RINT1's. The evolutionarily conserved NRZ likely acts as a tethering complex for retrograde trafficking of COPI vesicles from the Golgi to the endoplasmic reticulum. The RZZ, limited to metazoans, probably evolved from the NRZ, exploiting the dynein-binding capacity of ZW10 to direct dynein to kinetochores.
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Affiliation(s)
- Filiz Civril
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, I-20139 Milan, Italy
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17
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Royou A, Gagou ME, Karess R, Sullivan W. BubR1- and Polo-coated DNA tethers facilitate poleward segregation of acentric chromatids. Cell 2010; 140:235-45. [PMID: 20141837 DOI: 10.1016/j.cell.2009.12.043] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 10/13/2009] [Accepted: 12/21/2009] [Indexed: 11/29/2022]
Abstract
The mechanisms that safeguard cells against chromosomal instability (CIN) are of great interest, as CIN contributes to tumorigenesis. To gain insight into these mechanisms, we studied the behavior of cells entering mitosis with damaged chromosomes. We used the endonuclease I-CreI to generate acentric chromosomes in Drosophila larvae. While I-CreI expression produces acentric chromosomes in the majority of neuronal stem cells, remarkably, it has no effect on adult survival. Our live studies reveal that acentric chromatids segregate efficiently to opposite poles. The acentric chromatid poleward movement is mediated through DNA tethers decorated with BubR1, Polo, INCENP, and Aurora-B. Reduced BubR1 or Polo function results in abnormal segregation of acentric chromatids, a decrease in acentric chromosome tethering, and a great reduction in adult survival. We propose that BubR1 and Polo facilitate the accurate segregation of acentric chromatids by maintaining the integrity of the tethers that connect acentric chromosomes to their centric partners.
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Affiliation(s)
- Anne Royou
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
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18
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Lu Y, Wang Z, Ge L, Chen N, Liu H. The RZZ complex and the spindle assembly checkpoint. Cell Struct Funct 2009; 34:31-45. [PMID: 19420794 DOI: 10.1247/csf.08040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The conserved protein Rod is found in various organisms. It is localized on the kinetochores or spindle microtubules during cell division. Rod is required for proper chromosome segregation during both mitosis and meiosis. The effects of rod mutations are similar for both equational and reductional divisions, giving rise to anaphases with lagging chromosomes and/or unequal numbers of chromosomes at the two poles. Recent studies have shown that Rod is a significant component of the mitotic checkpoint. It can form the RZZ complex with Zw10 and Zwilch, which plays an important role in maintaining a functional spindle assembly checkpoint.
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Affiliation(s)
- Yujian Lu
- MOE Key Laboratory of Arid and Grassland Ecology, Institute of Cell Biology, Life Science School, Lanzhou University, Lanzhou, PR China
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19
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Abstract
The attachment of chromosomes to spindle microtubules during mitosis is a delicate and intricate process on which eukaryotic cells critically depend to maintain their ploidy. In this issue of Genes & Development, Gassmann and colleagues (pp. 2385-2399 present an analysis of the recently discovered Spindly/SPDL-1 protein that casts new lights onto the attachment process and the way it relates to the control of cell cycle progression.
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Affiliation(s)
- Filiz Civril
- Department of Experimental Oncology, European Institute of Oncology, I-20139 Milan, Italy
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20
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Gassmann R, Essex A, Hu JS, Maddox PS, Motegi F, Sugimoto A, O'Rourke SM, Bowerman B, McLeod I, Yates JR, Oegema K, Cheeseman IM, Desai A. A new mechanism controlling kinetochore-microtubule interactions revealed by comparison of two dynein-targeting components: SPDL-1 and the Rod/Zwilch/Zw10 complex. Genes Dev 2008; 22:2385-99. [PMID: 18765790 DOI: 10.1101/gad.1687508] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Chromosome segregation requires stable bipolar attachments of spindle microtubules to kinetochores. The dynein/dynactin motor complex localizes transiently to kinetochores and is implicated in chromosome segregation, but its role remains poorly understood. Here, we use the Caenorhabditis elegans embryo to investigate the function of kinetochore dynein by analyzing the Rod/Zwilch/Zw10 (RZZ) complex and the associated coiled-coil protein SPDL-1. Both components are essential for Mad2 targeting to kinetochores and spindle checkpoint activation. RZZ complex inhibition, which abolishes both SPDL-1 and dynein/dynactin targeting to kinetochores, slows but does not prevent the formation of load-bearing kinetochore-microtubule attachments and reduces the fidelity of chromosome segregation. Surprisingly, inhibition of SPDL-1, which abolishes dynein/dynactin targeting to kinetochores without perturbing RZZ complex localization, prevents the formation of load-bearing attachments during most of prometaphase and results in extensive chromosome missegregation. Coinhibition of SPDL-1 along with the RZZ complex reduces the phenotypic severity to that observed following RZZ complex inhibition alone. We propose that the RZZ complex can inhibit the formation of load-bearing attachments and that this activity of the RZZ complex is normally controlled by dynein/dynactin localized via SPDL-1. This mechanism could coordinate the hand-off from initial weak dynein-mediated lateral attachments, which help orient kinetochores and enhance their ability to capture microtubules, to strong end-coupled attachments that drive chromosome segregation.
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Affiliation(s)
- Reto Gassmann
- Ludwig Institute for Cancer Research/Dept of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, USA
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21
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Castellanos E, Dominguez P, Gonzalez C. Centrosome dysfunction in Drosophila neural stem cells causes tumors that are not due to genome instability. Curr Biol 2008; 18:1209-14. [PMID: 18656356 DOI: 10.1016/j.cub.2008.07.029] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 07/01/2008] [Accepted: 07/03/2008] [Indexed: 12/28/2022]
Abstract
Genome instability (GI) and centrosomal alterations are common traits in human cancer [1, 2]. It is suspected that centrosome dysfunction may cause tumors by bringing about GI, but direct experimental proof is still lacking [3]. To explore the possible functional link between centrosome function and overgrowth, we have assayed the tumorigenic potential of a series of mutants that affect different centrosomal proteins in Drosophila. We have found that a significant number of such mutant conditions are tumorigenic in larval brain tissue, where self-renewing asymmetric division of neural stem cells is frequent, but not in symmetrically dividing epithelial cells. We have also found that mutations that increase GI without causing centrosome dysfunction are not tumorigenic in our assay. From these observations, we conclude that the tumors caused by centrosome dysfunction cannot be explained solely by the resulting genome instability. We propose that such tumors might be caused by impaired asymmetric division of neural stem cells [4]. These results show that centrosome loss, far from being innocuous, is a potentially dangerous condition in flies.
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Affiliation(s)
- Elisabeth Castellanos
- Cell Division Group, IRB-Barcelona, PCB, c/ Baldiri Reixac 10-12, 08028 Barcelona, Spain
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22
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Lis1/dynactin regulates metaphase spindle orientation in Drosophila neuroblasts. Dev Biol 2008; 319:1-9. [PMID: 18485341 DOI: 10.1016/j.ydbio.2008.03.018] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 03/10/2008] [Accepted: 03/11/2008] [Indexed: 12/22/2022]
Abstract
Mitotic spindle orientation in polarized cells determines whether they divide symmetrically or asymmetrically. Moreover, regulated spindle orientation may be important for embryonic development, stem cell biology, and tumor growth. Drosophila neuroblasts align their spindle along an apical/basal cortical polarity axis to self-renew an apical neuroblast and generate a basal differentiating cell. It is unknown whether spindle alignment requires both apical and basal cues, nor have molecular motors been identified that regulate spindle movement. Using live imaging of neuroblasts within intact larval brains, we detect independent movement of both apical and basal spindle poles, suggesting that forces act on both poles. We show that reducing astral microtubules decreases the frequency of spindle movement, but not its maximum velocity, suggesting that one or few microtubules can move the spindle. Mutants in the Lis1/dynactin complex strongly decrease maximum and average spindle velocity, consistent with this motor complex mediating spindle/cortex forces. Loss of either astral microtubules or Lis1/dynactin leads to spindle/cortical polarity alignment defects at metaphase, but these are rescued by telophase. We propose that an early Lis1/dynactin-dependent pathway and a late Lis1/dynactin-independent pathway regulate neuroblast spindle orientation.
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23
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Famulski JK, Vos L, Sun X, Chan G. Stable hZW10 kinetochore residency, mediated by hZwint-1 interaction, is essential for the mitotic checkpoint. ACTA ACUST UNITED AC 2008; 180:507-20. [PMID: 18268100 PMCID: PMC2234252 DOI: 10.1083/jcb.200708021] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The mitotic checkpoint is an essential surveillance mechanism that ensures high fidelity chromosome segregation during mitosis. Mitotic checkpoint function depends on numerous kinetochore proteins, including ZW10, ROD, and Zwilch (the ROD–ZW10–Zwilch complex). Through an extensive mutagenesis screen of hZW10, we have mapped the kinetochore localization domain of hZW10 as well as the hZwint-1 interaction domain. We find that hZwint-1–noninteracting mutants still localize to kinetochores. In addition, using fluorescence recovery after photobleaching, we have found that hZW10 residency at metaphase kinetochores is brief (half-time of 13 s). However, during prometaphase or at unattached kinetochores, enhanced green fluorescent protein–hZW10 becomes a stable component of the kinetochore. Moreover, we find that stable hZW10 kinetochore residency at prometaphase kinetochores is dependent on its interaction with hZwint-1, and is essential for mitotic checkpoint arrest.
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Affiliation(s)
- Jakub K Famulski
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
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24
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Buffin E, Emre D, Karess RE. Flies without a spindle checkpoint. Nat Cell Biol 2007; 9:565-72. [PMID: 17417628 DOI: 10.1038/ncb1570] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Accepted: 03/15/2007] [Indexed: 11/08/2022]
Abstract
Mad2 has a key role in the spindle-assembly checkpoint (SAC) - the mechanism delaying anaphase onset until all chromosomes correctly attach to the spindle. Here, we show that unlike every other reported case of SAC inactivation in metazoans, mad2-null Drosophila are viable and fertile, and their cells almost always divide correctly despite having no SAC and an accelerated 'clock', which is caused by premature degradation of cyclin B. Mitosis in Drosophila does not need the SAC because correct chromosome attachment is achieved very rapidly, before even the cell lacking Mad2 can initiate anaphase. Experimentally reducing spindle-assembly efficiency renders the cells Mad2-dependent. In fact, the robustness of the SAC may generally mask minor mitotic defects of mutations affecting spindle function. The reported lethality of other Drosophila SAC mutations may be explained by their multifunctionality, and thus the 'checkpoint' phenotypes previously ascribed to these mutations should be considered the consequence of eliminating both the checkpoint and a second mitotic function.
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Affiliation(s)
- Eulalie Buffin
- CNRS, Centre de Génétique Moléculaire, Ave de la Terrasse, 91198 Gif sur Yvette, France
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25
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Vallee RB, Varma D, Dujardin DL. ZW10 function in mitotic checkpoint control, dynein targeting and membrane trafficking: is dynein the unifying theme? Cell Cycle 2006; 5:2447-51. [PMID: 17102640 PMCID: PMC2794429 DOI: 10.4161/cc.5.21.3395] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
ZW10 was initially identified as a mitotic checkpoint protein involved in chromosome segregation. It was subsequently implicated in targeting cytoplasmic dynein and dynactin to mitotic kinetochores, though the relationship between these functions remains incompletely understood. Recent studies have revealed that ZW10 performs important functions in nondividing cells as well. These include cytoplasmic dynein targeting to Golgi and other membranes, but also SNARE-mediated ER-Golgi trafficking. Identifying a unifying function for ZW10 in these diverse contexts has been elusive, but likely involves cytoplasmic dynein, as discussed here.
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Affiliation(s)
- Richard B Vallee
- Deptartment of Pathology and Cell Biology, Columbia University, New York, New York 10032, USA.
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26
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Chan GK, Liu ST, Yen TJ. Kinetochore structure and function. Trends Cell Biol 2005; 15:589-98. [PMID: 16214339 DOI: 10.1016/j.tcb.2005.09.010] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 08/30/2005] [Accepted: 09/22/2005] [Indexed: 11/16/2022]
Abstract
The vertebrate kinetochore is a complex structure that specifies the attachments between the chromosomes and microtubules of the spindle and is thus essential for accurate chromosome segregation. Kinetochores are assembled on centromeric chromatin through complex pathways that are coordinated with the cell cycle. In the light of recent discoveries on how proteins assemble onto kinetochores and interact with each other, we review these findings in this article (which is part of the Chromosome Segregation and Aneuploidy series), and discuss their implications for the current mitotic checkpoint models - the template model and the two-step model. The template model proposes that Mad1-Mad2 at kinetochores acts as a template to change the conformation of another binding molecule of Mad2. This templated change in conformation is postulated as a mechanism for the amplification of the 'anaphase wait' signal. The two-step model proposes that the mitotic checkpoint complex (MCC) is the kinetochore-independent anaphase inhibitor, and the role of the unaligned kinetochore is to sensitize the anaphase-promoting complex/cyclosome (APC/C) to MCC-mediated inhibition.
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Affiliation(s)
- Gordon K Chan
- Department of Oncology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 1Z2.
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27
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Siller KH, Serr M, Steward R, Hays TS, Doe CQ. Live imaging of Drosophila brain neuroblasts reveals a role for Lis1/dynactin in spindle assembly and mitotic checkpoint control. Mol Biol Cell 2005; 16:5127-40. [PMID: 16107559 PMCID: PMC1266413 DOI: 10.1091/mbc.e05-04-0338] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Revised: 07/08/2005] [Accepted: 08/10/2005] [Indexed: 01/28/2023] Open
Abstract
Lis1 is required for nuclear migration in fungi, cell cycle progression in mammals, and the formation of a folded cerebral cortex in humans. Lis1 binds dynactin and the dynein motor complex, but the role of Lis1 in many dynein/dynactin-dependent processes is not clearly understood. Here we generate and/or characterize mutants for Drosophila Lis1 and a dynactin subunit, Glued, to investigate the role of Lis1/dynactin in mitotic checkpoint function. In addition, we develop an improved time-lapse video microscopy technique that allows live imaging of GFP-Lis1, GFP-Rod checkpoint protein, green fluorescent protein (GFP)-labeled chromosomes, or GFP-labeled mitotic spindle dynamics in neuroblasts within whole larval brain explants. Our mutant analyses show that Lis1/dynactin have at least two independent functions during mitosis: first promoting centrosome separation and bipolar spindle assembly during prophase/prometaphase, and subsequently generating interkinetochore tension and transporting checkpoint proteins off kinetochores during metaphase, thus promoting timely anaphase onset. Furthermore, we show that Lis1/dynactin/dynein physically associate and colocalize on centrosomes, spindle MTs, and kinetochores, and that regulation of Lis1/dynactin kinetochore localization in Drosophila differs from both Caenorhabditis elegans and mammals. We conclude that Lis1/dynactin act together to regulate multiple, independent functions in mitotic cells, including spindle formation and cell cycle checkpoint release.
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28
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Kops GJPL, Kim Y, Weaver BAA, Mao Y, McLeod I, Yates JR, Tagaya M, Cleveland DW. ZW10 links mitotic checkpoint signaling to the structural kinetochore. ACTA ACUST UNITED AC 2005; 169:49-60. [PMID: 15824131 PMCID: PMC1351127 DOI: 10.1083/jcb.200411118] [Citation(s) in RCA: 187] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mitotic checkpoint ensures that chromosomes are divided equally between daughter cells and is a primary mechanism preventing the chromosome instability often seen in aneuploid human tumors. ZW10 and Rod play an essential role in this checkpoint. We show that in mitotic human cells ZW10 resides in a complex with Rod and Zwilch, whereas another ZW10 partner, Zwint-1, is part of a separate complex of structural kinetochore components including Mis12 and Ndc80-Hec1. Zwint-1 is critical for recruiting ZW10 to unattached kinetochores. Depletion from human cells or Xenopus egg extracts is used to demonstrate that the ZW10 complex is essential for stable binding of a Mad1-Mad2 complex to unattached kinetochores. Thus, ZW10 functions as a linker between the core structural elements of the outer kinetochore and components that catalyze generation of the mitotic checkpoint-derived "stop anaphase" inhibitor.
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Affiliation(s)
- Geert J P L Kops
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093, USA
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29
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Karess R. Rod–Zw10–Zwilch: a key player in the spindle checkpoint. Trends Cell Biol 2005; 15:386-92. [PMID: 15922598 DOI: 10.1016/j.tcb.2005.05.003] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 04/21/2005] [Accepted: 05/13/2005] [Indexed: 11/22/2022]
Abstract
The spindle checkpoint assures the proper segregation of chromosomes during mitosis. The best-characterized components of the checkpoint were originally identified in budding yeast. But three proteins with no yeast homologs--Rod, Zw10 and Zwilch--also play a crucial, but poorly understood, role in the metazoan spindle checkpoint. Recent work has begun to reveal the function of these proteins. The three form a complex (the RZZ complex), which is required for the recruitment of two better-known components of the kinetochore--the dynein-dynactin complex, and Mad1-Mad2. It has now been established that RZZ is directly or indirectly responsible for both Mad1-Mad2 recruitment to unattached kinetochores and its subsequent shedding from kinetochores following MT attachment, and thus is involved in both the activation and inactivation of the checkpoint. This review (which is part of the Chromosome Segregation and Aneuploidy series) covers recent developments in our understanding of RZZ dynamics and its function in the checkpoint.
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Affiliation(s)
- Roger Karess
- CNRS, Centre de Génétique Moléculaire, Ave de la Terrasse, 91198 Gif sur Yvette, France.
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30
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Royou A, Macias H, Sullivan W. The Drosophila Grp/Chk1 DNA damage checkpoint controls entry into anaphase. Curr Biol 2005; 15:334-9. [PMID: 15723794 DOI: 10.1016/j.cub.2005.02.026] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Revised: 12/10/2004] [Accepted: 12/14/2004] [Indexed: 12/19/2022]
Abstract
It is well established that DNA damage induces checkpoint-mediated interphase arrest in higher eukaryotes, but recent studies demonstrate that DNA damage delays entry into anaphase as well. Damaged DNA in syncytial and gastrulating Drosophila embryos delays the metaphase/anaphase transition . In human cultured cells, DNA damage also induces a delay in mitosis . However, the mechanism by which DNA damage delays the anaphase onset is controversial. Some studies implicate a DNA damage checkpoint , whereas other studies invoke a spindle checkpoint . To resolve this issue, we compared the effects of random DNA breaks induced by X-irradiation to site-specific I-CreI endonuclease-induced chromosome breaks on cell-cycle progression in wild-type and checkpoint-defective Drosophila neuroblasts. We found that both the BubR1 spindle checkpoint pathway and the Grp/Chk1 DNA damage checkpoint pathway are involved in delaying the metaphase/anaphase transition after extensive X-irradiation-induced DNA damage, whereas Grp/Chk1, but not BubR1, is required to delay anaphase onset in the presence of I-CreI-induced double-strand breaks. On the basis of these results, we propose that DNA damage in nonkinetochore regions produces a Grp/Chk1 DNA-damage-checkpoint-mediated delay in the metaphase/anaphase transition.
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Affiliation(s)
- Anne Royou
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064 USA
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31
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Glover DM. Polo kinase and progression through M phase in Drosophila: a perspective from the spindle poles. Oncogene 2005; 24:230-7. [PMID: 15640838 DOI: 10.1038/sj.onc.1208279] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Genes for the mitotic kinases Polo and Aurora A were first identified in Drosophila through screens of maternal effect lethal mutations for defects in spindle pole behaviour. These enzymes have been shown to be highly conserved and required for multiple functions in mitosis. Polo is stabilized at the centrosome by association with Hsp90. It is required for centrosome maturation on M-phase entry in order to recruit the gamma-tubulin ring complex and activate the abnormal spindle protein, Asp. These events facilitate the nucleation of minus ends of microtubules at the centrosome. The localization of Polo at the kinetochore and the mid-zone of the central spindle together with the phenotypes of polo mutants point to functions at the metaphase to anaphase transition and in cytokinesis. The latter are mediated, at least in part, through the Pavarotti kinesin-like motor protein and its conserved counterparts in other metazoans.
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Affiliation(s)
- David M Glover
- Cancer Research UK Cell Cycle Genetics Research Group, Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK.
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32
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Wang Z, Cummins JM, Shen D, Cahill DP, Jallepalli PV, Wang TL, Parsons DW, Traverso G, Awad M, Silliman N, Ptak J, Szabo S, Willson JKV, Markowitz SD, Goldberg ML, Karess R, Kinzler KW, Vogelstein B, Velculescu VE, Lengauer C. Three classes of genes mutated in colorectal cancers with chromosomal instability. Cancer Res 2004; 64:2998-3001. [PMID: 15126332 DOI: 10.1158/0008-5472.can-04-0587] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although most colorectal cancers are chromosomally unstable, the basis for this instability has not been defined. To determine whether genes shown to cause chromosomal instability in model systems were mutated in colorectal cancers, we identified their human homologues and determined their sequence in a panel of colorectal cancers. We found 19 somatic mutations in five genes representing three distinct instability pathways. Seven mutations were found in MRE11, whose product is involved in double-strand break repair. Four mutations were found among hZw10, hZwilch/FLJ10036, and hRod/KNTC, whose products bind to one another in a complex that localizes to kinetochores and controls chromosome segregation. Eight mutations were found in Ding, a previously uncharacterized gene with sequence similarity to the Saccharomyces cerevisiae Pds1, whose product is essential for proper chromosome disjunction. This analysis buttresses the evidence that chromosomal instability has a genetic basis and provides clues to the mechanistic basis of instability in cancers.
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Affiliation(s)
- Zhenghe Wang
- Sidney Kimmel Comprehensive Cancer Center and Howard Hughes Medical Institute at Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
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33
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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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34
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Scaërou F, Starr DA, Piano F, Papoulas O, Karess RE, Goldberg ML. The ZW10 and Rough Deal checkpoint proteins function together in a large, evolutionarily conserved complex targeted to the kinetochore. J Cell Sci 2001; 114:3103-14. [PMID: 11590237 DOI: 10.1242/jcs.114.17.3103] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The zeste-white 10 (zw10) and rough deal (rod) genes of Drosophila both encode kinetochore components, and mutations in either gene greatly increase the missegregation of sister chromatids during mitosis. Here, we present genetic, cytological and biochemical evidence for a close, evolutionarily conserved relationship between the ROD and ZW10 proteins. We show that the phenotypes caused by disruption of either gene’s function are similar in Drosophila and in C. elegans. No additive effects are observed in zw10; rod double null mutants. In flies, the two proteins always colocalize and, moreover, require each other for their recruitment to the mitotic apparatus. The human ROD and ZW10 homologs also colocalize on HeLa cell kinetochores or kinetochore microtubules throughout most but not all of mitosis. Finally, we show that in both Drosophila and human cells, ROD and ZW10 are in fact physically associated, and in Drosophila these proteins are together constituents of a large (700-900 kDa), soluble macromolecular complex.
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Affiliation(s)
- F Scaërou
- CNRS, Centre de Génétique Moléculaire, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
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35
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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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36
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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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37
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Afshar K, Gönczy P, DiNardo S, Wasserman SA. fumble encodes a pantothenate kinase homolog required for proper mitosis and meiosis in Drosophila melanogaster. Genetics 2001; 157:1267-76. [PMID: 11238410 PMCID: PMC1461544 DOI: 10.1093/genetics/157.3.1267] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A number of fundamental processes comprise the cell division cycle, including spindle formation, chromosome segregation, and cytokinesis. Our current understanding of these processes has benefited from the isolation and analysis of mutants, with the meiotic divisions in the male germline of Drosophila being particularly well suited to the identification of the required genes. We show here that the fumble (fbl) gene is required for cell division in Drosophila. We find that dividing cells in fbl-deficient testes exhibit abnormalities in bipolar spindle organization, chromosome segregation, and contractile ring formation. Cytological analysis of larval neuroblasts from null mutants reveals a reduced mitotic index and the presence of polyploid cells. Molecular analysis demonstrates that fbl encodes three protein isoforms, all of which contain a domain with high similarity to the pantothenate kinases of A. nidulans and mouse. The largest Fumble isoform is dispersed in the cytoplasm during interphase, concentrates around the spindle at metaphase, and localizes to the spindle midbody at telophase. During early embryonic development, the protein localizes to areas of membrane deposition and/or rearrangement, such as the metaphase and cellularization furrows. Given the role of pantothenate kinase in production of Coenzyme A and in phospholipid biosynthesis, this pattern of localization is suggestive of a role for fbl in membrane synthesis. We propose that abnormalities in synthesis and redistribution of membranous structures during the cell division cycle underlie the cell division defects in fbl mutant cells.
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Affiliation(s)
- K Afshar
- Center for Molecular Genetics, Division of Biology, University of California, San Diego, California 92093, USA.
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38
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Basto R, Gomes R, Karess RE. Rough deal and Zw10 are required for the metaphase checkpoint in Drosophila. Nat Cell Biol 2000; 2:939-43. [PMID: 11146659 DOI: 10.1038/35046592] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The metaphase-anaphase transition during mitosis is carefully regulated in order to assure high-fidelity transmission of genetic information to the daughter cells. A surveillance mechanism known as the metaphase checkpoint (or spindle-assembly checkpoint) monitors the attachment of kinetochores to the spindle microtubules, and inhibits anaphase onset until all chromosomes have achieved a proper bipolar orientation on the spindle. Defects in this checkpoint lead to premature anaphase onset, and consequently to greatly increased rates of aneuploidy. Here we show that the Drosophila kinetochore components Rough deal (Rod) and Zeste-White 10 (Zw10) are required for the proper functioning of the metaphase checkpoint in flies. Drosophila cells lacking either ROD or Zw10 exhibit a phenotype that is similar to that of bub1 mutants - they do not arrest in metaphase in response to spindle damage, but instead separate sister chromatids, degrade cyclin B and exit mitosis. These are the first checkpoint components to be identified that do not have obvious homologues in budding yeast.
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Affiliation(s)
- R Basto
- CNRS, Centre de Génétique Moléculaire, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
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39
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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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40
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Chan GK, Jablonski SA, Starr DA, Goldberg ML, Yen TJ. Human Zw10 and ROD are mitotic checkpoint proteins that bind to kinetochores. Nat Cell Biol 2000; 2:944-7. [PMID: 11146660 DOI: 10.1038/35046598] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Here we show that human Zeste White 10 (Zw10) and Rough deal (Rod) are new components of the mitotic checkpoint, as cells lacking these proteins at kinetochores fail to arrest in mitosis when exposed to microtubule inhibitors. Checkpoint failure and premature mitotic exit may explain why cells defective for hZw10 and hRod divide with lagging chromosomes. As Zw10 and Rod are not conserved in yeast, our data, combined with an accompanying study of Drosophila Zw10 and Rod, indicate that metazoans may require an elaborate spindle checkpoint to monitor complex kinetochore functions.
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Affiliation(s)
- G K Chan
- Fox Chase Cancer Center, 7701 Burholme Avenue, Philadelphia, Pennsylvania 19111, USA
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41
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Yucel JK, Marszalek JD, McIntosh JR, Goldstein LS, Cleveland DW, Philp AV. CENP-meta, an essential kinetochore kinesin required for the maintenance of metaphase chromosome alignment in Drosophila. J Cell Biol 2000; 150:1-11. [PMID: 10893249 PMCID: PMC2185570 DOI: 10.1083/jcb.150.1.1] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2000] [Accepted: 06/02/2000] [Indexed: 11/22/2022] Open
Abstract
CENP-meta has been identified as an essential, kinesin-like motor protein in Drosophila. The 257-kD CENP-meta protein is most similar to the vertebrate kinetochore-associated kinesin-like protein CENP-E, and like CENP-E, is shown to be a component of centromeric/kinetochore regions of Drosophila chromosomes. However, unlike CENP-E, which leaves the centromere/kinetochore region at the end of anaphase A, the CENP-meta protein remains associated with the centromeric/kinetochore region of the chromosome during all stages of the Drosophila cell cycle. P-element-mediated disruption of the CENP-meta gene leads to late larval/pupal stage lethality with incomplete chromosome alignment at metaphase. Complete removal of CENP-meta from the female germline leads to lethality in early embryos resulting from defects in metaphase chromosome alignment. Real-time imaging of these mutants with GFP-labeled chromosomes demonstrates that CENP-meta is required for the maintenance of chromosomes at the metaphase plate, demonstrating that the functions required to establish and maintain chromosome congression have distinguishable requirements.
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Affiliation(s)
- Jennifer K. Yucel
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Janet D. Marszalek
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093
| | - J. Richard McIntosh
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Lawrence S.B. Goldstein
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Don W. Cleveland
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093
- Department of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Alastair Valentine Philp
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093
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42
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Yucel JK, Marszalek JD, McIntosh JR, Goldstein LS, Cleveland DW, Philp AV. CENP-meta, an Essential Kinetochore Kinesin Required for the Maintenance of Metaphase Chromosome Alignment in Drosophila. J Cell Biol 2000. [DOI: 10.1083/jcb.150.1.1a] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
CENP-meta has been identified as an essential, kinesin-like motor protein in Drosophila. The 257-kD CENP-meta protein is most similar to the vertebrate kinetochore-associated kinesin-like protein CENP-E, and like CENP-E, is shown to be a component of centromeric/kinetochore regions of Drosophila chromosomes. However, unlike CENP-E, which leaves the centromere/kinetochore region at the end of anaphase A, the CENP-meta protein remains associated with the centromeric/kinetochore region of the chromosome during all stages of the Drosophila cell cycle. P-element–mediated disruption of the CENP-meta gene leads to late larval/pupal stage lethality with incomplete chromosome alignment at metaphase. Complete removal of CENP-meta from the female germline leads to lethality in early embryos resulting from defects in metaphase chromosome alignment. Real-time imaging of these mutants with GFP-labeled chromosomes demonstrates that CENP-meta is required for the maintenance of chromosomes at the metaphase plate, demonstrating that the functions required to establish and maintain chromosome congression have distinguishable requirements.
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Affiliation(s)
- Jennifer K. Yucel
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Janet D. Marszalek
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093
| | - J. Richard McIntosh
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Lawrence S.B. Goldstein
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Don W. Cleveland
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093
- Department of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Alastair Valentine Philp
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093
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43
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Scaërou F, Aguilera I, Saunders R, Kane N, Blottière L, Karess R. The rough deal protein is a new kinetochore component required for accurate chromosome segregation in Drosophila. J Cell Sci 1999; 112 ( Pt 21):3757-68. [PMID: 10523511 DOI: 10.1242/jcs.112.21.3757] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutations in the rough deal (rod) gene of Drosophila greatly increase the missegregation of sister chromatids during mitosis, suggesting a role for this gene product in spindle or kinetochore function. The activity provided by rod also appears to be necessary for the recruitment of two known kinetochore components, Zw10 and cytoplasmic dynein. In this paper we describe the cloning of rough deal and an initial cytological characterization of its product. The Rod protein shares no identifiable structural motif with other known proteins, although apparent homologs exist in the genomes of nematode and man. By immunocytochemistry we show that Rod displays a dynamic intracellular staining pattern, localizing first to kinetochores in prometaphase, but moving to kinetochore microtubules at metaphase. Early in anaphase the protein is once again restricted to the kinetochores, where it persists until the end of telophase. This behavior is in all respects similar to that described for Zw10, and suggests that the proteins function together.
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Affiliation(s)
- F Scaërou
- C.N.R.S., Centre de Génétique Moléculaire, Avenue de la Terrasse, France
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44
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Basu J, Bousbaa H, Logarinho E, Li Z, Williams BC, Lopes C, Sunkel CE, Goldberg ML. Mutations in the essential spindle checkpoint gene bub1 cause chromosome missegregation and fail to block apoptosis in Drosophila. J Cell Biol 1999; 146:13-28. [PMID: 10402457 PMCID: PMC2199734 DOI: 10.1083/jcb.146.1.13] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We have characterized the Drosophila mitotic checkpoint control protein Bub1 and obtained mutations in the bub1 gene. Drosophila Bub1 localizes strongly to the centromere/kinetochore of mitotic and meiotic chromosomes that have not yet reached the metaphase plate. Animals homozygous for P-element-induced, near-null mutations of bub1 die during late larval/pupal stages due to severe mitotic abnormalities indicative of a bypass of checkpoint function. These abnormalities include accelerated exit from metaphase and chromosome missegregation and fragmentation. Chromosome fragmentation possibly leads to the significantly elevated levels of apoptosis seen in mutants. We have also investigated the relationship between Bub1 and other kinetochore components. We show that Bub1 kinase activity is not required for phosphorylation of 3F3/2 epitopes at prophase/prometaphase, but is needed for 3F3/2 dephosphorylation at metaphase. Neither 3F3/2 dephosphorylation nor loss of Bub1 from the kinetochore is a prerequisite for anaphase entry. Bub1's localization to the kinetochore does not depend on the products of the genes zw10, rod, polo, or fizzy, indicating that the kinetochore is constructed from several independent subassemblies.
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Affiliation(s)
- Joydeep Basu
- Section of Genetics and Development, Cornell University, Ithaca, New York 14853
| | - Hassan Bousbaa
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150 Porto, Portugal
| | - Elsa Logarinho
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150 Porto, Portugal
| | - ZeXiao Li
- Section of Genetics and Development, Cornell University, Ithaca, New York 14853
| | - Byron C. Williams
- Section of Genetics and Development, Cornell University, Ithaca, New York 14853
| | - Carla Lopes
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150 Porto, Portugal
| | - Claudio E. Sunkel
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150 Porto, Portugal
- Instituto de Abel Salazar, Universidade do Porto, 4050 Porto, Portugal
| | - Michael L. Goldberg
- Section of Genetics and Development, Cornell University, Ithaca, New York 14853
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45
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Craig JM, Earnshaw WC, Vagnarelli P. Mammalian centromeres: DNA sequence, protein composition, and role in cell cycle progression. Exp Cell Res 1999; 246:249-62. [PMID: 9925740 DOI: 10.1006/excr.1998.4278] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The centromere is a specialized region of the eukaryotic chromosome that is responsible for directing chromosome movements in mitosis and for coordinating the progression of mitotic events at the crucial transition between metaphase and anaphase. In this review, we will focus on recent advances in the understanding of centromere composition at the protein and DNA level and of the role of centromeres in sister-chromatid cohesion and mitotic checkpoint control.
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Affiliation(s)
- J M Craig
- Institute of Cell and Molecular Biology, University of Edinburgh, Edinburgh, EH9 3JR, Scotland, United Kingdom
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46
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Starr DA, Williams BC, Hays TS, Goldberg ML. ZW10 helps recruit dynactin and dynein to the kinetochore. J Cell Biol 1998; 142:763-74. [PMID: 9700164 PMCID: PMC2148168 DOI: 10.1083/jcb.142.3.763] [Citation(s) in RCA: 222] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/1998] [Revised: 07/01/1998] [Indexed: 02/08/2023] Open
Abstract
Mutations in the Drosophila melanogaster zw10 gene, which encodes a conserved, essential kinetochore component, abolish the ability of dynein to localize to kinetochores. Several similarities between the behavior of ZW10 protein and dynein further support a role for ZW10 in the recruitment of dynein to the kinetochore: (a) in response to bipolar tension across the chromosomes, both proteins mostly leave the kinetochore at metaphase, when their association with the spindle becomes apparent; (b) ZW10 and dynein both bind to functional neocentromeres of structurally acentric minichromosomes; and (c) the localization of both ZW10 and dynein to the kinetochore is abolished in cells mutant for the gene rough deal. ZW10's role in the recruitment of dynein to the kinetochore is likely to be reasonably direct, because dynamitin, the p50 subunit of the dynactin complex, interacts with ZW10 in a yeast two-hybrid screen. Since in zw10 mutants no defects in chromosome behavior are observed before anaphase onset, our results suggest that dynein at the kinetochore is essential for neither microtubule capture nor congression to the metaphase plate. Instead, dynein's role at the kinetochore is more likely to be involved in the coordination of chromosome separation and/or poleward movement at anaphase onset.
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Affiliation(s)
- D A Starr
- Section of Genetics and Development, Cornell University, Ithaca, New York 14853-2703, USA
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47
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Kodjabachian L, Delaage M, Maurel C, Miassod R, Jacq B, Rosset R. Mutations in ccf, a novel Drosophila gene encoding a chromosomal factor, affect progression through mitosis and interact with Pc-G mutations. EMBO J 1998; 17:1063-75. [PMID: 9463384 PMCID: PMC1170455 DOI: 10.1093/emboj/17.4.1063] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We report herein the isolation of ccf, a new gene located in region 82E and essential for Drosophila development. This gene, expressed throughout development, encodes a novel product of 68 kDa which is found in the nucleus during interphase and labels, in a novel pattern, centrosomes and chromosome arms during mitosis. Mutations in ccf give rise to late larvae with small imaginal discs and to adults showing appendages of reduced size, consistent with CCF involvement in cell proliferation. Neuroblast squash analyses show that CCF is required for proper condensation of mitotic chromosomes and, therefore, for progression through mitosis. Furthermore, we observe that adult ccf mutants as well as animals overexpressing CCF during larval stages exhibit homeotic transformations. We also find that mutations in the Pc-G genes Polycomb, polyhomeotic and Enhancer of zeste are enhanced by ccf mutations. Finally, we show that the CCF protein binds to specific sites on polytene chromosomes, many of which are shared with the Posterior sex combs Pc-G protein. Together, these results suggest a role for the CCF protein in the maintenance of chromosome structure during mitosis and interphase.
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Affiliation(s)
- L Kodjabachian
- Laboratoire de Génétique et Physiologie du Développement, Institut de Biologie du Développement de Marseille, CNRS Case 907, France.
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48
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Starr DA, Williams BC, Li Z, Etemad-Moghadam B, Dawe RK, Goldberg ML. Conservation of the centromere/kinetochore protein ZW10. J Cell Biol 1997; 138:1289-301. [PMID: 9298984 PMCID: PMC2132553 DOI: 10.1083/jcb.138.6.1289] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Mutations in the essential Drosophila melanogaster gene zw10 disrupt chromosome segregation, producing chromosomes that lag at the metaphase plate during anaphase of mitosis and both meiotic divisions. Recent evidence suggests that the product of this gene, DmZW10, acts at the kinetochore as part of a tension-sensing checkpoint at anaphase onset. DmZW10 displays an intriguing cell cycle-dependent intracellular distribution, apparently moving from the centromere/kinetochore at prometaphase to kinetochore microtubules at metaphase, and back to the centromere/kinetochore at anaphase (Williams, B.C., M. Gatti, and M.L. Goldberg. 1996. J. Cell Biol. 134:1127-1140). We have identified ZW10-related proteins from widely diverse species with divergent centromere structures, including several Drosophilids, Caenorhabditis elegans, Arabidopsis thaliana, Mus musculus, and humans. Antibodies against the human ZW10 protein display a cell cycle-dependent staining pattern in HeLa cells strikingly similar to that previously observed for DmZW10 in dividing Drosophila cells. Injections of C. elegans ZW10 antisense RNA phenocopies important aspects of the mutant phenotype in Drosophila: these include a strong decrease in brood size, suggesting defects in meiosis or germline mitosis, a high percentage of lethality among the embryos that are produced, and the appearance of chromatin bridges at anaphase. These results indicate that at least some aspects of the functional role of the ZW10 protein in ensuring proper chromosome segregation are conserved across large evolutionary distances.
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Affiliation(s)
- D A Starr
- Section of Genetics and Development, Cornell University, Ithaca, New York 14853-2703, USA
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49
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Wilson PG, Fuller MT, Borisy GG. Monastral bipolar spindles: implications for dynamic centrosome organization. J Cell Sci 1997; 110 ( Pt 4):451-64. [PMID: 9067597 DOI: 10.1242/jcs.110.4.451] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Implicit to all models for mitotic spindle assembly is the view that centrosomes are essentially permanent structures. Yet, immunofluorescence revealed that spindles in larval brains of urchin mutants in Drosophila were frequently monastral but bipolar; the astral pole contained a centrosome while the opposing anastral pole showed neither gamma tubulin nor a radial array of astral microtubules. Thus, mutations in the urchin gene seem to uncouple centrosome organization and spindle bipolarity in mitotic cells. Hypomorphic mutants showed a high frequency of monastral bipolar spindles but low frequencies of polyploidy, suggesting that monastral bipolar spindles might be functional. To test this hypothesis, we performed pedigree analysis of centrosome distribution and spindle structure in the four mitotic divisions of gonial cells. Prophase gonial cells showed two centrosomes, suggesting cells entered mitosis with the normal number of centrosomes and that centrosomes separated during prophase. Despite a high frequency of monastral bipolar spindles, the end products of the four mitotic divisions were equivalent in size and chromatin content. These results indicate that monastral bipolar spindles are functional and that the daughter cell derived from the anastral pole can assemble a functional bipolar spindle in the subsequent cell cycle. Cell proliferation despite high frequencies of monastral bipolar spindles can be explained if centrosome structure in mitotic cells is dynamic, allowing transient and benign disorganization of pericentriolar components. Since urchin proved to be allelic to KLP61F which encodes a kinesin related motor protein (Heck et al. (1993) J. Cell Biol. 123, 665–671), our results suggest that motors influence the dynamic organization of centrosomes.
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Affiliation(s)
- P G Wilson
- Laboratory of Molecular Biology, University of Wisconsin, Madison 53706, USA
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50
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Charlesworth B. Background selection and patterns of genetic diversity in Drosophila melanogaster. Genet Res (Camb) 1996; 68:131-49. [PMID: 8940902 DOI: 10.1017/s0016672300034029] [Citation(s) in RCA: 211] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Theoretical models of the effects of selection against deleterious mutations on variation at linked neutral sites (background selection) are used to predict the relations between chromosomal location and genetic variability at the DNA level, in Drosophila melanogaster. The sensitivity of the predictions to variation in the mutation, selection and recombination parameters on which they are based is examined. It is shown that many features of the observed relations between chromosomal location and level of genetic diversity in D. melanogaster can be explained by background selection, especially if the weak selective forces acting on transposable elements are taken into account. In particular, the gradient in diversity in the distal portion of the X chromosome, and the lack of diversity on chromosome 4 and at the bases of the major chromosomes, can be fully accounted for. There are, however, discrepancies between predicted and observed values for some loci in D. melanogaster, which may reflect the effects of forces other than background selection.
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