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Li Q, Chen Q, Zheng T, Wang F, Teng J, Zhou H, Chen J. CCDC68 Maintains Mitotic Checkpoint Activation by Promoting CDC20 Integration into the MCC. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2406009. [PMID: 39018254 PMCID: PMC11425217 DOI: 10.1002/advs.202406009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Indexed: 07/19/2024]
Abstract
The spindle assembly checkpoint (SAC) ensures chromosome segregation fidelity by manipulating unattached kinetochore-dependent assembly of the mitotic checkpoint complex (MCC). The MCC binds to and inhibits the anaphase promoting complex/cyclosome (APC/C) to postpone mitotic exit. However, the mechanism by which unattached kinetochores mediate MCC formation is not yet fully understood. Here, it is shown that CCDC68 is an outer kinetochore protein that preferentially localizes to unattached kinetochores. Furthermore, CCDC68 interacts with the SAC factor CDC20 to inhibit its autoubiquitination and MCC disassembly. Therefore, CCDC68 restrains APC/C activation to ensure a robust SAC and allow sufficient time for chromosome alignment, thus ensuring chromosomal stability. Hence, the study reveals that CCDC68 is required for CDC20-dependent MCC stabilization to maintain mitotic checkpoint activation.
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Affiliation(s)
- Qi Li
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Qingzhou Chen
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Tao Zheng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Fulin Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Junlin Teng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing, 100871, China
| | - Haining Zhou
- Key Laboratory of Epigenetic Regulation and Intervention, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jianguo Chen
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing, 100871, China
- Center for Quantitative Biology, Peking University, Beijing, 100871, China
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2
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Hinshaw SM, Quan Y, Cai J, Zhou AL, Zhou H. Multi-site phosphorylation of yeast Mif2/CENP-C promotes inner kinetochore assembly. Curr Biol 2023; 33:688-696.e6. [PMID: 36736323 PMCID: PMC9992315 DOI: 10.1016/j.cub.2023.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/28/2022] [Accepted: 01/09/2023] [Indexed: 02/05/2023]
Abstract
Kinetochores control eukaryotic chromosome segregation by connecting chromosomal centromeres to spindle microtubules. Duplication of centromeric DNA necessitates kinetochore disassembly and subsequent reassembly on nascent sisters. To search for a regulatory mechanism that controls the earliest steps of this process, we studied Mif2/CENP-C, an essential basal component of the kinetochore. We found that phosphorylation of a central region of Mif2 (Mif2-PEST) enhances inner kinetochore assembly. Eliminating Mif2-PEST phosphorylation sites progressively impairs cellular fitness. The most severe Mif2-PEST mutations are lethal in cells lacking otherwise non-essential inner kinetochore factors. These data show that multi-site phosphorylation of Mif2/CENP-C controls inner kinetochore assembly.
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Affiliation(s)
- Stephen M Hinshaw
- Stanford Cancer Institute, Stanford School of Medicine, 1291 Welch Road, Stanford, CA 94305, USA.
| | - Yun Quan
- Department of Cellular and Molecular Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92039, USA
| | - Jiaxi Cai
- Department of Cellular and Molecular Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92039, USA
| | - Ann L Zhou
- Department of Cellular and Molecular Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92039, USA
| | - Huilin Zhou
- Department of Cellular and Molecular Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92039, USA.
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3
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Zhao Y, Yang J, Lu D, Zhu Y, Liao K, Tian Y, Yin R. The Loss-Function of KNL1 Causes Oligospermia and Asthenospermia in Mice by Affecting the Assembly and Separation of the Spindle through Flow Cytometry and Immunofluorescence. SENSORS (BASEL, SWITZERLAND) 2023; 23:2571. [PMID: 36904774 PMCID: PMC10007211 DOI: 10.3390/s23052571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/13/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
KNL1 (kinetochore scaffold 1) has attracted much attention as one of the assembly elements of the outer kinetochore, and the functions of its different domains have been gradually revealed, most of which are associated with cancers, but few links have been made between KNL1 and male fertility. Here, we first linked KNL1 to male reproductive health and the loss-function of KNL1 resulted in oligospermia and asthenospermia in mice (an 86.5% decrease in total sperm number and an 82.4% increase in static sperm number, respectively) through CASA (computer-aided sperm analysis). Moreover, we introduced an ingenious method to pinpoint the abnormal stage in the spermatogenic cycle using flow cytometry combined with immunofluorescence. Results showed that 49.5% haploid sperm was reduced and 53.2% diploid sperm was increased after the function of KNL1 was lost. Spermatocytes arrest was identified at the meiotic prophase I of spermatogenesis, which was induced by the abnormal assembly and separation of the spindle. In conclusion, we established an association between KNL1 and male fertility, providing a guide for future genetic counseling regarding oligospermia and asthenospermia, and a powerful method for further exploring spermatogenic dysfunction by utilizing flow cytometry and immunofluorescence.
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Affiliation(s)
- Yuwei Zhao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
| | - Jingmin Yang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
- Shanghai WeHealth BioMedical Technology Co., Ltd., Shanghai 201318, China
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
| | - Daru Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
| | - Yijian Zhu
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
| | - Kai Liao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
| | - Yafei Tian
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
- Shanghai WeHealth BioMedical Technology Co., Ltd., Shanghai 201318, China
| | - Rui Yin
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
- Reproductive Medicine Research Center, Medical Research Institute, Southwest University, Chongqing 400715, China
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4
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Wang B, Wei W, Long S, Wang L, Yang B, Wu D, Li Z, Li Z, Arshad M, Li X, Chen J. CENPA acts as a prognostic factor that relates to immune infiltrates in gliomas. Front Neurol 2022; 13:1015221. [DOI: 10.3389/fneur.2022.1015221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 09/23/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundGlioma is the most common primary tumor of the central nervous system (CNS). Centromere protein A (CENPA) plays an essential role in ensuring that mitosis proceeds normally. The effect of CENPA on glioma is rarely reported. However, the current study aims to explore whether aberrant CENPA expression promotes glioma progression and the potential mechanisms involved.MethodsThe GEPIA website, The Cancer Genome Atlas, and the Gene Expression Omnibus (GEO) were used to assess the expression of CENPA in glioma. The results were validated by real-time quantitative polymerase chain reaction and immunohistochemical staining of clinical samples. The relationship between the expression and prognostic value of the CENPA gene in glioma was investigated by Kaplan–Meier (KM) survival analysis with RNA-seq and clinical profiles downloaded from the Chinese Glioma Genome Atlas (CGGA) and UCSC Xena. The association between CENPA and clinical characteristics was also evaluated. Cell Counting Kit-8 (CCK8) assay, wound healing assay using two glioma cell lines, gene set enrichment analysis (GSEA), KEGG and gene ontology (GO) enrichment analysis, immune infiltration analysis, temozolomide (TMZ) sensitivity analysis, and single-cell sequence analysis were performed to explore the underlying mechanisms of high CENPA expression and its effect on glioma development. Finally, we performed a Cox analysis based on the expression of CENPA to predict patient prognosis.ResultsCENPA was significantly upregulated in glioma tissue samples and correlated with patient prognosis. Moreover, the downregulation of CENPA inhibited the migration and proliferation of glioma cells. In addition, the expression level of CENPA was significantly correlated with the grade, primary–recurrent–secondary (PRS) type, IDH mutation status, and 1p19q codeletion status. Furthermore, CENPA could serve as an independent prognostic factor for glioma that mainly interferes with the normal progression of mitosis and regulates the tumor immune microenvironment favoring glioma development.ConclusionCENPA may act as a prognostic factor in patients with glioma and provide a novel target for the treatment of gliomas.
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Jamasbi E, Hamelian M, Hossain MA, Varmira K. The cell cycle, cancer development and therapy. Mol Biol Rep 2022; 49:10875-10883. [PMID: 35931874 DOI: 10.1007/s11033-022-07788-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 07/11/2022] [Indexed: 10/16/2022]
Abstract
The process of cell division plays a vital role in cancer progression. Cell proliferation and error-free chromosomes segregation during mitosis are central events in life cycle. Mistakes during cell division generate changes in chromosome content and alter the balances of chromosomes number. Any defects in expression of TIF1 family proteins, SAC proteins network, mitotic checkpoint proteins involved in chromosome mis-segregation and cancer development. Here we discuss the function of organelles deal with the chromosome segregation machinery, proteins and correction mechanisms involved in the accurate chromosome segregation during mitosis.
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Affiliation(s)
- Elaheh Jamasbi
- Research Center of Oils and Fats (RCOF), Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mona Hamelian
- Research Center of Oils and Fats (RCOF), Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammed Akhter Hossain
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Kambiz Varmira
- Research Center of Oils and Fats (RCOF), Kermanshah University of Medical Sciences, Kermanshah, Iran.
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Mora-Bermúdez F, Kanis P, Macak D, Peters J, Naumann R, Xing L, Sarov M, Winkler S, Oegema CE, Haffner C, Wimberger P, Riesenberg S, Maricic T, Huttner WB, Pääbo S. Longer metaphase and fewer chromosome segregation errors in modern human than Neanderthal brain development. SCIENCE ADVANCES 2022; 8:eabn7702. [PMID: 35905187 PMCID: PMC9337762 DOI: 10.1126/sciadv.abn7702] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Since the ancestors of modern humans separated from those of Neanderthals, around 100 amino acid substitutions spread to essentially all modern humans. The biological significance of these changes is largely unknown. Here, we examine all six such amino acid substitutions in three proteins known to have key roles in kinetochore function and chromosome segregation and to be highly expressed in the stem cells of the developing neocortex. When we introduce these modern human-specific substitutions in mice, three substitutions in two of these proteins, KIF18a and KNL1, cause metaphase prolongation and fewer chromosome segregation errors in apical progenitors of the developing neocortex. Conversely, the ancestral substitutions cause shorter metaphase length and more chromosome segregation errors in human brain organoids, similar to what we find in chimpanzee organoids. These results imply that the fidelity of chromosome segregation during neocortex development improved in modern humans after their divergence from Neanderthals.
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Affiliation(s)
- Felipe Mora-Bermúdez
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Philipp Kanis
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Dominik Macak
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Jula Peters
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ronald Naumann
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Lei Xing
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Mihail Sarov
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Sylke Winkler
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | | | - Christiane Haffner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Pauline Wimberger
- Department of Gynecology and Obstetrics, Technische Universität Dresden, Dresden, Germany
| | | | - Tomislav Maricic
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Wieland B. Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Svante Pääbo
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Okinawa Institute of Science and Technology, Onna-son 904-0495, Japan
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7
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McVey SL, Olson MA, Pawlowski WP, Nannas NJ. Beyond Editing, CRISPR/Cas9 For Protein Localization: An Educational Primer for Use with "A dCas9-Based System Identifies a Central Role for Ctf19 in Kinetochore-Derived Suppression of Meiotic Recombination". Genetics 2022; 222:6650694. [PMID: 35894926 PMCID: PMC9434236 DOI: 10.1093/genetics/iyac109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/07/2022] [Indexed: 11/14/2022] Open
Abstract
CRISPR/Cas9 has dramatically changed how we conduct genetic research, providing a tool for precise sequence editing. However, new applications of CRISPR/Cas9 have emerged that do not involve nuclease activity. In the accompanying article "A dCas9-Based System Identifies a Central Role for Ctf19 in Kinetochore-Derived Suppression of Meiotic Recombination", Kuhl and colleagues utilize a catalytically dead Cas9 to localize proteins at specific genomic locations. The authors seek to understand the role of kinetochore proteins in the suppression of meiotic recombination, a phenomenon that has been observed in centromere regions. By harnessing the power of CRISPR/Cas9 to bind specific genomic sequences, Kuhl et al. localized individual kinetochore proteins to areas of high meiotic recombination and assessed their role in suppression. This primer article provides undergraduate students with background information on chromosomes, meiosis, recombination and CRISPR/Cas9 to support their reading of the Kuhl et al. study. This primer is intended to help students and instructors navigate the study's experimental design, interpret the results, and appreciate the broader scope of meiotic recombination and CRISPR/Cas9. Questions are included to facilitate discussion of the study.
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Affiliation(s)
- Shelby L McVey
- Department of Biology, Hamilton College, Clinton, NY 13323, USA
| | - Mischa A Olson
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14850, USA
| | - Wojciech P Pawlowski
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14850, USA.,Section of Plant Breeding and Genetics, School of Integrative Plant Science, Cornell University, Ithaca, NY 14850 USA
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8
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Kouznetsova A, Liu JG, Valentiniene S, Brismar H, Höög C. Age-dependent aneuploidy in mammalian oocytes instigated at the second meiotic division. Aging Cell 2022; 21:e13649. [PMID: 35665589 PMCID: PMC9282850 DOI: 10.1111/acel.13649] [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] [Received: 10/22/2021] [Revised: 02/07/2022] [Accepted: 05/18/2022] [Indexed: 11/08/2022] Open
Abstract
Ageing severely affects the chromosome segregation process in human oocytes resulting in aneuploidy, infertility and developmental disorders. A considerable amount of segregation errors in humans are introduced at the second meiotic division. We have here compared the chromosome segregation process in young adult and aged female mice during the second meiotic division. More than half of the oocytes in aged mice displayed chromosome segregation irregularities at anaphase II, resulting in dramatically increased level of aneuploidy in haploid gametes, from 4% in young adult mice to 30% in aged mice. We find that the post‐metaphase II process that efficiently corrects aberrant kinetochore‐microtubule attachments in oocytes in young adult mice is approximately 10‐fold less efficient in aged mice, in particular affecting chromosomes that show small inter‐centromere distances at the metaphase II stage in aged mice. Our results reveal that post‐metaphase II processes have critical impact on age‐dependent aneuploidy in mammalian eggs.
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Affiliation(s)
- Anna Kouznetsova
- Department of Cell and Molecular Biology Karolinska Institutet Stockholm Sweden
| | - Jian Guo Liu
- Department of Cell and Molecular Biology Karolinska Institutet Stockholm Sweden
| | - Sonata Valentiniene
- Department of Cell and Molecular Biology Karolinska Institutet Stockholm Sweden
| | - Hjalmar Brismar
- Science for Life Laboratory, Department of Applied Physics Royal Institute of Technology Solna Sweden
| | - Christer Höög
- Department of Cell and Molecular Biology Karolinska Institutet Stockholm Sweden
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9
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Ccp1-Ndc80 switch at the N terminus of CENP-T regulates kinetochore assembly. Proc Natl Acad Sci U S A 2021; 118:2104459118. [PMID: 34810257 PMCID: PMC8640933 DOI: 10.1073/pnas.2104459118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2021] [Indexed: 11/18/2022] Open
Abstract
Precise chromosome segregation relies on kinetochores. How kinetochores are precisely assembled on centromeres through the cell cycle remains poorly understood. Centromeres in most eukaryotes are epigenetically marked by nucleosomes containing the histone H3 variant, CENP-A. Here, we demonstrated that Ccp1, an anti–CENP-A loading factor, interacts with the N terminus of CENP-T to promote the assembly of the outer kinetochore Ndc80 complex. This work further suggests that competitive exclusion between Ccp1 and Ndc80 at the N terminus of CENP-T via phosphorylation ensures precise kinetochore assembly during mitosis. In addition, CENP-T is critical for Ccp1 centromeric localization, which in turn regulates CENP-A distribution. Our results reveal a previously unrecognized mechanism underlying kinetochore assembly through the cell cycle. Kinetochores, a protein complex assembled on centromeres, mediate chromosome segregation. In most eukaryotes, centromeres are epigenetically specified by the histone H3 variant CENP-A. CENP-T, an inner kinetochore protein, serves as a platform for the assembly of the outer kinetochore Ndc80 complex during mitosis. How CENP-T is regulated through the cell cycle remains unclear. Ccp1 (counteracter of CENP-A loading protein 1) associates with centromeres during interphase but delocalizes from centromeres during mitosis. Here, we demonstrated that Ccp1 directly interacts with CENP-T. CENP-T is important for the association of Ccp1 with centromeres, whereas CENP-T centromeric localization depends on Mis16, a homolog of human RbAp48/46. We identified a Ccp1-interaction motif (CIM) at the N terminus of CENP-T, which is adjacent to the Ndc80 receptor motif. The CIM domain is required for Ccp1 centromeric localization, and the CIM domain–deleted mutant phenocopies ccp1Δ. The CIM domain can be phosphorylated by CDK1 (cyclin-dependent kinase 1). Phosphorylation of CIM weakens its interaction with Ccp1. Consistent with this, Ccp1 dissociates from centromeres through all stages of the cell cycle in the phosphomimetic mutant of the CIM domain, whereas in the phospho-null mutant of the domain, Ccp1 associates with centromeres during mitosis. We further show that the phospho-null mutant disrupts the positioning of the Ndc80 complex during mitosis, resulting in chromosome missegregation. This work suggests that competitive exclusion between Ccp1 and Ndc80 at the N terminus of CENP-T via phosphorylation ensures precise kinetochore assembly during mitosis and uncovers a previously unrecognized mechanism underlying kinetochore assembly through the cell cycle.
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10
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Russi M, Marson D, Fermeglia A, Aulic S, Fermeglia M, Laurini E, Pricl S. The fellowship of the RING: BRCA1, its partner BARD1 and their liaison in DNA repair and cancer. Pharmacol Ther 2021; 232:108009. [PMID: 34619284 DOI: 10.1016/j.pharmthera.2021.108009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 08/22/2021] [Accepted: 09/20/2021] [Indexed: 12/12/2022]
Abstract
The breast cancer type 1 susceptibility protein (BRCA1) and its partner - the BRCA1-associated RING domain protein 1 (BARD1) - are key players in a plethora of fundamental biological functions including, among others, DNA repair, replication fork protection, cell cycle progression, telomere maintenance, chromatin remodeling, apoptosis and tumor suppression. However, mutations in their encoding genes transform them into dangerous threats, and substantially increase the risk of developing cancer and other malignancies during the lifetime of the affected individuals. Understanding how BRCA1 and BARD1 perform their biological activities therefore not only provides a powerful mean to prevent such fatal occurrences but can also pave the way to the development of new targeted therapeutics. Thus, through this review work we aim at presenting the major efforts focused on the functional characterization and structural insights of BRCA1 and BARD1, per se and in combination with all their principal mediators and regulators, and on the multifaceted roles these proteins play in the maintenance of human genome integrity.
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Affiliation(s)
- Maria Russi
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Domenico Marson
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Alice Fermeglia
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Suzana Aulic
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Maurizio Fermeglia
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Erik Laurini
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Sabrina Pricl
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy; Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
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11
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Pajpach F, Wu T, Shearwin-Whyatt L, Jones K, Grützner F. Flavors of Non-Random Meiotic Segregation of Autosomes and Sex Chromosomes. Genes (Basel) 2021; 12:genes12091338. [PMID: 34573322 PMCID: PMC8471020 DOI: 10.3390/genes12091338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 12/14/2022] Open
Abstract
Segregation of chromosomes is a multistep process occurring both at mitosis and meiosis to ensure that daughter cells receive a complete set of genetic information. Critical components in the chromosome segregation include centromeres, kinetochores, components of sister chromatid and homologous chromosomes cohesion, microtubule organizing centres, and spindles. Based on the cytological work in the grasshopper Brachystola, it has been accepted for decades that segregation of homologs at meiosis is fundamentally random. This ensures that alleles on chromosomes have equal chance to be transmitted to progeny. At the same time mechanisms of meiotic drive and an increasing number of other examples of non-random segregation of autosomes and sex chromosomes provide insights into the underlying mechanisms of chromosome segregation but also question the textbook dogma of random chromosome segregation. Recent advances provide a better understanding of meiotic drive as a prominent force where cellular and chromosomal changes allow autosomes to bias their segregation. Less understood are mechanisms explaining observations that autosomal heteromorphism may cause biased segregation and regulate alternating segregation of multiple sex chromosome systems or translocation heterozygotes as an extreme case of non-random segregation. We speculate that molecular and cytological mechanisms of non-random segregation might be common in these cases and that there might be a continuous transition between random and non-random segregation which may play a role in the evolution of sexually antagonistic genes and sex chromosome evolution.
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Affiliation(s)
- Filip Pajpach
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (F.P.); (L.S.-W.)
| | - Tianyu Wu
- Department of Central Laboratory, Clinical Laboratory, Jing’an District Centre Hospital of Shanghai and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China;
| | - Linda Shearwin-Whyatt
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (F.P.); (L.S.-W.)
| | - Keith Jones
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RH, UK;
| | - Frank Grützner
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (F.P.); (L.S.-W.)
- Correspondence:
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12
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Pajpach F, Shearwin-Whyatt L, Grützner F. Evolution, Expression and Meiotic Behavior of Genes Involved in Chromosome Segregation of Monotremes. Genes (Basel) 2021; 12:1320. [PMID: 34573302 PMCID: PMC8470780 DOI: 10.3390/genes12091320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
Chromosome segregation at mitosis and meiosis is a highly dynamic and tightly regulated process that involves a large number of components. Due to the fundamental nature of chromosome segregation, many genes involved in this process are evolutionarily highly conserved, but duplications and functional diversification has occurred in various lineages. In order to better understand the evolution of genes involved in chromosome segregation in mammals, we analyzed some of the key components in the basal mammalian lineage of egg-laying mammals. The chromosome passenger complex is a multiprotein complex central to chromosome segregation during both mitosis and meiosis. It consists of survivin, borealin, inner centromere protein, and Aurora kinase B or C. We confirm the absence of Aurora kinase C in marsupials and show its absence in both platypus and echidna, which supports the current model of the evolution of Aurora kinases. High expression of AURKBC, an ancestor of AURKB and AURKC present in monotremes, suggests that this gene is performing all necessary meiotic functions in monotremes. Other genes of the chromosome passenger complex complex are present and conserved in monotremes, suggesting that their function has been preserved in mammals. Cohesins are another family of genes that are of vital importance for chromosome cohesion and segregation at mitosis and meiosis. Previous work has demonstrated an accumulation and differential loading of structural maintenance of chromosomes 3 (SMC3) on the platypus sex chromosome complex at meiotic prophase I. We investigated if a similar accumulation occurs in the echidna during meiosis I. In contrast to platypus, SMC3 was only found on the synaptonemal complex in echidna. This indicates that the specific distribution of SMC3 on the sex chromosome complex may have evolved specifically in platypus.
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Affiliation(s)
| | | | - Frank Grützner
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (F.P.); (L.S.-W.)
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13
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Herlihy CP, Hahn S, Hermance NM, Crowley EA, Manning AL. Suv420 enrichment at the centromere limits Aurora B localization and function. J Cell Sci 2021; 134:jcs249763. [PMID: 34342353 PMCID: PMC8353524 DOI: 10.1242/jcs.249763] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/05/2021] [Indexed: 12/16/2022] Open
Abstract
Centromere structure and function are defined by the epigenetic modification of histones at centromeric and pericentromeric chromatin. The constitutive heterochromatin found at pericentromeric regions is highly enriched for H3K9me3 and H4K20me3. Although mis-expression of the methyltransferase enzymes that regulate these marks, Suv39 and Suv420, is common in disease, the consequences of such changes are not well understood. Our data show that increased centromere localization of Suv39 and Suv420 suppresses centromere transcription and compromises localization of the mitotic kinase Aurora B, decreasing microtubule dynamics and compromising chromosome alignment and segregation. We find that inhibition of Suv420 methyltransferase activity partially restores Aurora B localization to centromeres and that restoration of the Aurora B-containing chromosomal passenger complex to the centromere is sufficient to suppress mitotic errors that result when Suv420 and H4K20me3 is enriched at centromeres. Consistent with a role for Suv39 and Suv420 in negatively regulating Aurora B, high expression of these enzymes corresponds with increased sensitivity to Aurora kinase inhibition in human cancer cells, suggesting that increased H3K9 and H4K20 methylation may be an underappreciated source of chromosome mis-segregation in cancer. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | | | | | | | - Amity L. Manning
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, 01609USA
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14
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Quan Y, Hinshaw SM, Wang PC, Harrison SC, Zhou H. Ctf3/CENP-I provides a docking site for the desumoylase Ulp2 at the kinetochore. THE JOURNAL OF CELL BIOLOGY 2021; 220:212227. [PMID: 34081091 PMCID: PMC8178754 DOI: 10.1083/jcb.202012149] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/24/2021] [Accepted: 05/17/2021] [Indexed: 01/10/2023]
Abstract
The step-by-step process of chromosome segregation defines the stages of the cell cycle. In eukaryotes, signals controlling these steps converge upon the kinetochore, a multiprotein assembly that connects spindle microtubules to chromosomal centromeres. Kinetochores control and adapt to major chromosomal transactions, including replication of centromeric DNA, biorientation of sister centromeres on the metaphase spindle, and transit of sister chromatids into daughter cells during anaphase. Although the mechanisms that ensure tight microtubule coupling at anaphase are at least partly understood, kinetochore adaptations that support other cell cycle transitions are not. We report here a mechanism that enables regulated control of kinetochore sumoylation. A conserved surface of the Ctf3/CENP-I kinetochore protein provides a binding site for Ulp2, the nuclear enzyme that removes SUMO chains from modified substrates. Ctf3 mutations that disable Ulp2 recruitment cause elevated inner kinetochore sumoylation and defective chromosome segregation. The location of the site within the assembled kinetochore suggests coordination between sumoylation and other cell cycle–regulated processes.
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Affiliation(s)
- Yun Quan
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA
| | - Stephen M Hinshaw
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Howard Hughes Medical Institute, Boston, MA
| | - Pang-Che Wang
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Howard Hughes Medical Institute, Boston, MA
| | - Huilin Zhou
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA
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15
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Gama Braga L, Prifti DK, Garand C, Saini PK, Elowe S. A quantitative and semiautomated method for determining misaligned and lagging chromosomes during mitosis. Mol Biol Cell 2021; 32:880-891. [PMID: 33085580 PMCID: PMC8108530 DOI: 10.1091/mbc.e20-09-0585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 01/21/2023] Open
Abstract
Accurate chromosome alignment at metaphase facilitates the equal segregation of sister chromatids to each of the nascent daughter cells. Lack of proper metaphase alignment is an indicator of defective chromosome congression and aberrant kinetochore-microtubule attachments which in turn promotes chromosome missegregation and aneuploidy, hallmarks of cancer. Tools to sensitively, accurately, and quantitatively measure chromosome alignment at metaphase will facilitate understanding of the contribution of chromosome segregation errors to the development of aneuploidy. In this work, we have developed and validated a method based on analytical geometry to measure several indicators of chromosome misalignment. We generated semiautomated and flexible ImageJ2/Fiji pipelines to quantify kinetochore misalignment at metaphase plates as well as lagging chromosomes at anaphase. These tools will ultimately allow sensitive and systematic quantitation of these chromosome segregation defects in cells undergoing mitosis.
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Affiliation(s)
- Luciano Gama Braga
- Programme en Biologie cellulaire et moléculaire, Faculté de Médicine Université Laval, Québec, QC G1V 0A6, Canada
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe de réproduction, santé de la mère et de l’enfant, Québec, QC G1V 4G2, Canada
- PROTEO-regroupement québécois de recherche sur la fonction, l’ingénierie et les applications des protéines, Québec, QC G1V 0A6, Canada
| | - Diogjena Katerina Prifti
- Programme en Biologie cellulaire et moléculaire, Faculté de Médicine Université Laval, Québec, QC G1V 0A6, Canada
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe de réproduction, santé de la mère et de l’enfant, Québec, QC G1V 4G2, Canada
- PROTEO-regroupement québécois de recherche sur la fonction, l’ingénierie et les applications des protéines, Québec, QC G1V 0A6, Canada
| | - Chantal Garand
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe de réproduction, santé de la mère et de l’enfant, Québec, QC G1V 4G2, Canada
| | - Pawan Kumar Saini
- Programme en Médicine moléculaire, Faculté de Médicine Université Laval, Québec, QC G1V 0A6, Canada
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe de réproduction, santé de la mère et de l’enfant, Québec, QC G1V 4G2, Canada
- PROTEO-regroupement québécois de recherche sur la fonction, l’ingénierie et les applications des protéines, Québec, QC G1V 0A6, Canada
| | - Sabine Elowe
- Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe de réproduction, santé de la mère et de l’enfant, Québec, QC G1V 4G2, Canada
- PROTEO-regroupement québécois de recherche sur la fonction, l’ingénierie et les applications des protéines, Québec, QC G1V 0A6, Canada
- Département de Pédiatire, Faculté de Médicine, Université Laval et le Centre de recherche sur le cancer de l’Université Laval, Québec, QC G1R 2J6, Canada
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16
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Doornbos C, Roepman R. Moonlighting of mitotic regulators in cilium disassembly. Cell Mol Life Sci 2021; 78:4955-4972. [PMID: 33860332 PMCID: PMC8233288 DOI: 10.1007/s00018-021-03827-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 03/03/2021] [Accepted: 03/27/2021] [Indexed: 02/07/2023]
Abstract
Correct timing of cellular processes is essential during embryological development and to maintain the balance between healthy proliferation and tumour formation. Assembly and disassembly of the primary cilium, the cell’s sensory signalling organelle, are linked to cell cycle timing in the same manner as spindle pole assembly and chromosome segregation. Mitotic processes, ciliary assembly, and ciliary disassembly depend on the centrioles as microtubule-organizing centres (MTOC) to regulate polymerizing and depolymerizing microtubules. Subsequently, other functional protein modules are gathered to potentiate specific protein–protein interactions. In this review, we show that a significant subset of key mitotic regulator proteins is moonlighting at the cilium, among which PLK1, AURKA, CDC20, and their regulators. Although ciliary assembly defects are linked to a variety of ciliopathies, ciliary disassembly defects are more often linked to brain development and tumour formation. Acquiring a better understanding of the overlap in regulators of ciliary disassembly and mitosis is essential in finding therapeutic targets for the different diseases and types of tumours associated with these regulators.
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Affiliation(s)
- Cenna Doornbos
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands. .,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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17
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To nucleate or not, that is the question in neurons. Neurosci Lett 2021; 751:135806. [PMID: 33705928 DOI: 10.1016/j.neulet.2021.135806] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/23/2021] [Accepted: 02/26/2021] [Indexed: 01/19/2023]
Abstract
Microtubules are the structural center of neurons, stretching in overlapping arrays from the cell body to the far reaches of axons and dendrites. They also act as the tracks for long-range transport mediated by dynein and kinesin motors. Transcription and most translation take place in the cell body, and newly made cargoes must be shipped from this site of synthesis to sites of function in axons and dendrites. This constant demand for transport means that the microtubule array must be present without gaps throughout the cell over the lifetime of the animal. This task is made slightly easier in many animals by the relatively long, stable microtubules present in neurons. However, even stable neuronal microtubules have ends that are dynamic, and individual microtubules typically last on the order of hours, while the neurons around them last a lifetime. "Birth" of new microtubules is therefore required to maintain the neuronal microtubule array. In this review we discuss the nucleation of new microtubules in axons and dendrites, including how and where they are nucleated. In addition, it is becoming clear that neuronal microtubule nucleation is highly regulated, with unexpected machinery impinging on the decision of whether nucleation sites are active or inactive through space and time.
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18
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The Proteomic Landscape of Centromeric Chromatin Reveals an Essential Role for the Ctf19 CCAN Complex in Meiotic Kinetochore Assembly. Curr Biol 2021; 31:283-296.e7. [PMID: 33157029 PMCID: PMC7846277 DOI: 10.1016/j.cub.2020.10.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/10/2020] [Accepted: 10/08/2020] [Indexed: 11/23/2022]
Abstract
Kinetochores direct chromosome segregation in mitosis and meiosis. Faithful gamete formation through meiosis requires that kinetochores take on new functions that impact homolog pairing, recombination, and the orientation of kinetochore attachment to microtubules in meiosis I. Using an unbiased proteomics pipeline, we determined the composition of centromeric chromatin and kinetochores at distinct cell-cycle stages, revealing extensive reorganization of kinetochores during meiosis. The data uncover a network of meiotic chromosome axis and recombination proteins that bind to centromeres in the absence of the microtubule-binding outer kinetochore sub-complexes during meiotic prophase. We show that the Ctf19cCCAN inner kinetochore complex is essential for kinetochore organization in meiosis. Our functional analyses identify a Ctf19cCCAN-dependent kinetochore assembly pathway that is dispensable for mitotic growth but becomes critical upon meiotic entry. Therefore, changes in kinetochore composition and a distinct assembly pathway specialize meiotic kinetochores for successful gametogenesis. The composition of meiotic centromeres and kinetochores is revealed Kinetochores undergo extensive changes between meiotic prophase I and metaphase I The Ctf19CCAN orchestrates meiotic kinetochore specialization A Ctf19CCAN-directed kinetochore assembly pathway is uniquely critical in meiosis
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19
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Xu Y, Liang C, Cai X, Zhang M, Yu W, Shao Q. High Centromere Protein-A (CENP-A) Expression Correlates with Progression and Prognosis in Gastric Cancer. Onco Targets Ther 2020; 13:13237-13246. [PMID: 33402833 PMCID: PMC7778524 DOI: 10.2147/ott.s263512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/04/2020] [Indexed: 12/14/2022] Open
Abstract
Purpose Recent studies have established the ability of centromere protein-A (CENP-A) to perform as an oncogene, regulating tumor progression. The aim of this research was to explore the relationship between CENP-A expression and clinical significance in gastric cancer (GC) patients. Materials and Methods Experiments with a microarray were conducted using the Affymetrix U133 plus 2.0 GeneChip Array. Upregulated differentially expressed genes (DEGs) were identified via the GEO2R and intersected using a Venn diagram. Bioinformatic databases Omcomine, GEPIA, and Ualcan were applied to investigate the expression level of CENP-A in GC. The real-time quantitative RT-PCR (qRT-PCR) was used to validate the level of CENP-A mRNA in GC. Immunohistochemistry (IHC) was employed to verify the protein levels of CENP-A, while the relationship between CENP-A expression and patients’ clinical parameters in GC was explored through the use of IHC. Kaplan-Meier analysis was conducted to evaluate the prognostic significance of CENP-A. Additionally, the Kaplan-Meier plotter database (KM plotter) was used to verify the prognostic function of CENP-A in GC patients. Results The results indicated that CENP-A was significantly overexpressed, both in protein and mRNA levels of GC tissues, compared to adjacent noncancerous tissues (P<0.05). Furthermore, we observed that CENP-A expression was positively associated with TNM stage, tumor classification, lymph node metastasis, distant metastasis, and Lauren type (P<0.05). Kaplan-Meier analysis showed that patients with an overexpression of CENP-A had significantly poorer overall survival (OS) times (P<0.05). Multivariate analysis suggested CENP-A may serve as an independent predicting factor for the poor outcome of GC patients. Conclusion Our results show that CENP-A upregulation is significantly correlated with advanced tumor progression and poor prognosis. CENP-A may function as a novel potential biomarker for predicting the clinical outcomes of GC patients.
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Affiliation(s)
- Yuan Xu
- Department of Gastrointestinal Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo 315000, People's Republic of China
| | - Chao Liang
- Department of Gastrointestinal Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo 315000, People's Republic of China
| | - Xianlei Cai
- Department of Gastrointestinal Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo 315000, People's Republic of China
| | - Miaozun Zhang
- Department of Gastrointestinal Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo 315000, People's Republic of China
| | - Weiming Yu
- Department of Gastrointestinal Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo 315000, People's Republic of China
| | - Qinshu Shao
- Department of Gastrointestinal Pancreatic Surgery, Zhejiang Provincial People's Hospital, Hangzhou 310014, People's Republic of China
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20
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Saint-Leandre B, Christopher C, Levine MT. Adaptive evolution of an essential telomere protein restricts telomeric retrotransposons. eLife 2020; 9:e60987. [PMID: 33350936 PMCID: PMC7755394 DOI: 10.7554/elife.60987] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023] Open
Abstract
Essential, conserved cellular processes depend not only on essential, strictly conserved proteins but also on essential proteins that evolve rapidly. To probe this poorly understood paradox, we exploited the rapidly evolving Drosophila telomere-binding protein, cav/HOAP, which protects chromosomes from lethal end-to-end fusions. We replaced the D. melanogaster HOAP with a highly diverged version from its close relative, D. yakuba. The D. yakuba HOAP ('HOAP[yak]') localizes to D. melanogaster telomeres and protects D. melanogaster chromosomes from fusions. However, HOAP[yak] fails to rescue a previously uncharacterized HOAP function: silencing of the specialized telomeric retrotransposons that, instead of telomerase, maintain chromosome length in Drosophila. Whole genome sequencing and cytogenetics of experimentally evolved populations revealed that HOAP[yak] triggers telomeric retrotransposon proliferation, resulting in aberrantly long telomeres. This evolution-generated, separation-of-function allele resolves the paradoxical observation that a fast-evolving essential gene directs an essential, strictly conserved function: telomeric retrotransposon containment, not end-protection, requires evolutionary innovation at HOAP.
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Affiliation(s)
- Bastien Saint-Leandre
- Department of Biology and Epigenetics Institute, University of PennsylvaniaPhiladelphiaUnited States
| | - Courtney Christopher
- Department of Biology and Epigenetics Institute, University of PennsylvaniaPhiladelphiaUnited States
| | - Mia T Levine
- Department of Biology and Epigenetics Institute, University of PennsylvaniaPhiladelphiaUnited States
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21
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Ng CT, Ladinsky MS, Gan L. Serial Cryomicrotomy of Saccharomyces cerevisiae for Serial Electron Cryotomography. Bio Protoc 2020; 10:e3831. [PMID: 33659481 DOI: 10.21769/bioprotoc.3831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 11/02/2022] Open
Abstract
Electron cryotomography (cryo-ET) is an increasingly popular technique to study cellular structures and macromolecules in situ. Due to poor penetration of electrons through thick biological samples, the vitreously frozen samples for cryo-ET need to be thin. For frozen-hydrated cells, such samples can be produced either by cryomicrotomy or cryo-FIB-milling. As a result, a tomogram of such a sample contains information of a small fraction of the entire cell volume, making it challenging to image rare structures in the cell or to determine the distribution of scattered structures. Here, we describe the tools and workflow that we designed to facilitate serial cryomicrotomy, which makes possible the exploration of a larger volume of individual cells at molecular resolution. We successfully used serial cryomicrotomy to locate and image the Dam1/DASH complex located at microtubule plus ends inside mitotic Saccharomyces cerevisiae cells.
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Affiliation(s)
- Cai Tong Ng
- Centre of BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Mark S Ladinsky
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, USA
| | - Lu Gan
- Centre of BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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22
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Kukreja AA, Kavuri S, Joglekar AP. Microtubule Attachment and Centromeric Tension Shape the Protein Architecture of the Human Kinetochore. Curr Biol 2020; 30:4869-4881.e5. [PMID: 33035484 DOI: 10.1016/j.cub.2020.09.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/23/2020] [Accepted: 09/14/2020] [Indexed: 12/18/2022]
Abstract
The nanoscale protein architecture of the kinetochore plays an integral role in specifying the mechanisms underlying its functions in chromosome segregation. However, defining this architecture in human cells remains challenging because of the large size and compositional complexity of the kinetochore. Here, we use Förster resonance energy transfer to reveal the architecture of individual kinetochore-microtubule attachments in human cells. We find that the microtubule-binding domains of the Ndc80 complex cluster at the microtubule plus end. This clustering occurs only after microtubule attachment, and it increases proportionally with centromeric tension. Surprisingly, Ndc80 complex clustering is independent of the organization and number of its centromeric receptors. Moreover, this clustering is similar in yeast and human kinetochores despite significant differences in their centromeric organizations. These and other data suggest that the microtubule-binding interface of the human kinetochore behaves like a flexible "lawn" despite being nucleated by repeating biochemical subunits.
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Affiliation(s)
- Alexander A Kukreja
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109, USA
| | - Sisira Kavuri
- Department of Cellular & Developmental Biology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Ajit P Joglekar
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109, USA; Department of Cellular & Developmental Biology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA.
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23
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Hertzler JI, Simonovitch SI, Albertson RM, Weiner AT, Nye DMR, Rolls MM. Kinetochore proteins suppress neuronal microtubule dynamics and promote dendrite regeneration. Mol Biol Cell 2020; 31:2125-2138. [PMID: 32673176 PMCID: PMC7530905 DOI: 10.1091/mbc.e20-04-0237-t] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Kinetochores connect centromeric chromatin to spindle microtubules during mitosis. Neurons are postmitotic, so it was surprising to identify transcripts of structural kinetochore (KT) proteins and regulatory chromosome passenger complex (CPC) and spindle assembly checkpoint (SAC) proteins in Drosophila neurons after dendrite injury. To test whether these proteins function during dendrite regeneration, postmitotic RNA interference (RNAi) was performed and dendrites or axons were removed using laser microsurgery. Reduction of KT, CPC, and SAC proteins decreased dendrite regeneration without affecting axon regeneration. To understand whether neuronal functions of these proteins rely on microtubules, we analyzed microtubule behavior in uninjured neurons. The number of growing plus, but not minus, ends increased in dendrites with reduced KT, CPC, and SAC proteins, while axonal microtubules were unaffected. Increased dendritic microtubule dynamics was independent of dual leucine zipper kinase (DLK)-mediated stress but was rescued by concurrent reduction of γ-tubulin, the core microtubule nucleation protein. Reduction of γ-tubulin also rescued dendrite regeneration in backgrounds containing kinetochore RNAi transgenes. We conclude that kinetochore proteins function postmitotically in neurons to suppress dendritic microtubule dynamics by inhibiting nucleation.
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Affiliation(s)
- James I Hertzler
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Samantha I Simonovitch
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Richard M Albertson
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802.,MSTP Program, Milton S. Hershey College of Medicine, Hershey, PA 17033
| | - Alexis T Weiner
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Derek M R Nye
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802.,MSTP Program, Milton S. Hershey College of Medicine, Hershey, PA 17033
| | - Melissa M Rolls
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
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24
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Prc1-rich kinetochores are required for error-free acentrosomal spindle bipolarization during meiosis I in mouse oocytes. Nat Commun 2020; 11:2652. [PMID: 32461611 PMCID: PMC7253481 DOI: 10.1038/s41467-020-16488-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 05/01/2020] [Indexed: 12/18/2022] Open
Abstract
Acentrosomal meiosis in oocytes represents a gametogenic challenge, requiring spindle bipolarization without predefined bipolar cues. While much is known about the structures that promote acentrosomal microtubule nucleation, less is known about the structures that mediate spindle bipolarization in mammalian oocytes. Here, we show that in mouse oocytes, kinetochores are required for spindle bipolarization in meiosis I. This process is promoted by oocyte-specific, microtubule-independent enrichment of the antiparallel microtubule crosslinker Prc1 at kinetochores via the Ndc80 complex. In contrast, in meiosis II, cytoplasm that contains upregulated factors including Prc1 supports kinetochore-independent pathways for spindle bipolarization. The kinetochore-dependent mode of spindle bipolarization is required for meiosis I to prevent chromosome segregation errors. Human oocytes, where spindle bipolarization is reportedly error prone, exhibit no detectable kinetochore enrichment of Prc1. This study reveals an oocyte-specific function of kinetochores in acentrosomal spindle bipolarization in mice, and provides insights into the error-prone nature of human oocytes. Oocyte meiosis must achieve spindle bipolarization without predefined spatial cues. Yoshida et al. demonstrate that spindle bipolarization during meiosis I in mouse oocytes requires kinetochores to prevent chromosome segregation errors, a phenomenon that does not occur in error-prone human oocytes.
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25
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Migl D, Kschonsak M, Arthur CP, Khin Y, Harrison SC, Ciferri C, Dimitrova YN. Cryoelectron Microscopy Structure of a Yeast Centromeric Nucleosome at 2.7 Å Resolution. Structure 2020; 28:363-370.e3. [PMID: 32004465 PMCID: PMC7166091 DOI: 10.1016/j.str.2019.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/17/2019] [Accepted: 12/02/2019] [Indexed: 12/21/2022]
Abstract
Kinetochores mediate chromosome segregation during cell division. They assemble on centromeric nucleosomes and capture spindle microtubules. In budding yeast, a kinetochore links a single nucleosome, containing the histone variant Cse4CENP-A instead of H3, with a single microtubule. Conservation of most kinetochore components from yeast to metazoans suggests that the yeast kinetochore represents a module of the more complex metazoan arrangements. We describe here a streamlined protocol for reconstituting a yeast centromeric nucleosome and a systematic exploration of cryo-grid preparation. These developments allowed us to obtain a high-resolution cryoelectron microscopy reconstruction. As suggested by previous work, fewer base pairs are in tight association with the histone octamer than there are in canonical nucleosomes. Weak binding of the end DNA sequences may contribute to specific recognition by other inner kinetochore components. The centromeric nucleosome structure and the strategies we describe will facilitate studies of many other aspects of kinetochore assembly and chromatin biochemistry.
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Affiliation(s)
- David Migl
- Harvard Medical School, Boston, MA 02115, USA; Biophysics Program, Harvard University, Boston, MA 02115, USA
| | - Marc Kschonsak
- Structural Biology, Genentech, South San Francisco, CA, USA
| | | | - Yadana Khin
- Harvard Medical School, Boston, MA 02115, USA
| | - Stephen C Harrison
- Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA.
| | - Claudio Ciferri
- Structural Biology, Genentech, South San Francisco, CA, USA.
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26
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Edelmaier C, Lamson AR, Gergely ZR, Ansari S, Blackwell R, McIntosh JR, Glaser MA, Betterton MD. Mechanisms of chromosome biorientation and bipolar spindle assembly analyzed by computational modeling. eLife 2020; 9:48787. [PMID: 32053104 PMCID: PMC7311174 DOI: 10.7554/elife.48787] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 02/12/2020] [Indexed: 01/19/2023] Open
Abstract
The essential functions required for mitotic spindle assembly and chromosome biorientation and segregation are not fully understood, despite extensive study. To illuminate the combinations of ingredients most important to align and segregate chromosomes and simultaneously assemble a bipolar spindle, we developed a computational model of fission-yeast mitosis. Robust chromosome biorientation requires progressive restriction of attachment geometry, destabilization of misaligned attachments, and attachment force dependence. Large spindle length fluctuations can occur when the kinetochore-microtubule attachment lifetime is long. The primary spindle force generators are kinesin-5 motors and crosslinkers in early mitosis, while interkinetochore stretch becomes important after biorientation. The same mechanisms that contribute to persistent biorientation lead to segregation of chromosomes to the poles after anaphase onset. This model therefore provides a framework to interrogate key requirements for robust chromosome biorientation, spindle length regulation, and force generation in the spindle. Before a cell divides, it must make a copy of its genetic material and then promptly split in two. This process, called mitosis, is coordinated by many different molecular machines. The DNA is copied, then the duplicated chromosomes line up at the middle of the cell. Next, an apparatus called the mitotic spindle latches onto the chromosomes before pulling them apart. The mitotic spindle is a bundle of long, thin filaments called microtubules. It attaches to chromosomes at the kinetochore, the point where two copied chromosomes are cinched together in their middle. Proper cell division is vital for the healthy growth of all organisms, big and small, and yet some parts of the process remain poorly understood despite extensive study. Specifically, there is more to learn about how the mitotic spindle self-assembles, and how microtubules and kinetochores work together to correctly orient and segregate chromosomes into two sister cells. These nanoscale processes are happening a hundred times a minute, so computer simulations are a good way to test what we know. Edelmaier et al. developed a computer model to simulate cell division in fission yeast, a species of yeast often used to study fundamental processes in the cell. The model simulates how the mitotic spindle assembles, how its microtubules attach to the kinetochore and the force required to pull two sister chromosomes apart. Building the simulation involved modelling interactions between the mitotic spindle and kinetochore, their movement and forces applied. To test its accuracy, model simulations were compared to recordings of the mitotic spindle – including its length, structure and position – imaged from dividing yeast cells. Running the simulation, Edelmaier et al. found that several key effects are essential for the proper movement of chromosomes in mitosis. This includes holding chromosomes in the correct orientation as the mitotic spindle assembles and controlling the relative position of microtubules as they attach to the kinetochore. Misaligned attachments must also be readily deconstructed and corrected to prevent any errors. The simulations also showed that kinetochores must begin to exert more force (to separate the chromosomes) once the mitotic spindle is attached correctly. Altogether, these findings improve the current understanding of how the mitotic spindle and its counterparts control cell division. Errors in chromosome segregation are associated with birth defects and cancer in humans, and this new simulation could potentially now be used to help make predictions about how to correct mistakes in the process.
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Affiliation(s)
| | - Adam R Lamson
- Department of Physics, University of Colorado Boulder, Boulder, United States
| | - Zachary R Gergely
- Department of Physics, University of Colorado Boulder, Boulder, United States.,Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Saad Ansari
- Department of Physics, University of Colorado Boulder, Boulder, United States
| | - Robert Blackwell
- Department of Physics, University of Colorado Boulder, Boulder, United States
| | - J Richard McIntosh
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Matthew A Glaser
- Department of Physics, University of Colorado Boulder, Boulder, United States
| | - Meredith D Betterton
- Department of Physics, University of Colorado Boulder, Boulder, United States.,Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
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27
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Bucko PJ, Lombard CK, Rathbun L, Garcia I, Bhat A, Wordeman L, Smith FD, Maly DJ, Hehnly H, Scott JD. Subcellular drug targeting illuminates local kinase action. eLife 2019; 8:e52220. [PMID: 31872801 PMCID: PMC6930117 DOI: 10.7554/elife.52220] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/30/2019] [Indexed: 01/02/2023] Open
Abstract
Deciphering how signaling enzymes operate within discrete microenvironments is fundamental to understanding biological processes. A-kinase anchoring proteins (AKAPs) restrict the range of action of protein kinases within intracellular compartments. We exploited the AKAP targeting concept to create genetically encoded platforms that restrain kinase inhibitor drugs at distinct subcellular locations. Local Kinase Inhibition (LoKI) allows us to ascribe organelle-specific functions to broad specificity kinases. Using chemical genetics, super resolution microscopy, and live-cell imaging we discover that centrosomal delivery of Polo-like kinase 1 (Plk1) and Aurora A (AurA) inhibitors attenuates kinase activity, produces spindle defects, and prolongs mitosis. Targeted inhibition of Plk1 in zebrafish embryos illustrates how centrosomal Plk1 underlies mitotic spindle assembly. Inhibition of kinetochore-associated pools of AurA blocks phosphorylation of microtubule-kinetochore components. This versatile precision pharmacology tool enhances investigation of local kinase biology.
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Affiliation(s)
- Paula J Bucko
- Department of PharmacologyUniversity of WashingtonSeattleUnited States
| | - Chloe K Lombard
- Department of ChemistryUniversity of WashingtonSeattleUnited States
| | - Lindsay Rathbun
- Department of BiologySyracuse UniversitySyracuseUnited States
| | - Irvin Garcia
- Department of PharmacologyUniversity of WashingtonSeattleUnited States
| | - Akansha Bhat
- Department of PharmacologyUniversity of WashingtonSeattleUnited States
| | - Linda Wordeman
- Department of Physiology and BiophysicsUniversity of WashingtonSeattleUnited States
| | - F Donelson Smith
- Department of PharmacologyUniversity of WashingtonSeattleUnited States
| | - Dustin J Maly
- Department of ChemistryUniversity of WashingtonSeattleUnited States
| | - Heidi Hehnly
- Department of BiologySyracuse UniversitySyracuseUnited States
| | - John D Scott
- Department of PharmacologyUniversity of WashingtonSeattleUnited States
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29
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Del Castillo U, Norkett R, Gelfand VI. Unconventional Roles of Cytoskeletal Mitotic Machinery in Neurodevelopment. Trends Cell Biol 2019; 29:901-911. [PMID: 31597609 DOI: 10.1016/j.tcb.2019.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/22/2019] [Accepted: 08/23/2019] [Indexed: 12/20/2022]
Abstract
At first look, cell division and neurite formation seem to be two different, essential biological processes. However, both processes require extensive reorganization of the cytoskeleton, and especially microtubules. Remarkably, in recent years, independent work from several groups has shown that multiple cytoskeletal components previously considered specific for the mitotic machinery play important roles in neurite initiation and extension. In this review article, we describe how several cytoplasmic and mitotic microtubule motors, components of mitotic kinetochores, and cortical actin participate in reorganization of the microtubule network required to form and maintain axons and dendrites. The emerging similarities between these two biological processes will certainly generate new insights into the mechanisms generating the unique morphology of neurons.
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Affiliation(s)
- Urko Del Castillo
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA
| | - Rosalind Norkett
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA
| | - Vladimir I Gelfand
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA.
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30
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Hu L, Huang H, Hei M, Yang Y, Li S, Liu Y, Dou Z, Wu M, Li J, Wang GZ, Yao X, Liu H, He X, Tian W. Structural analysis of fungal CENP-H/I/K homologs reveals a conserved assembly mechanism underlying proper chromosome alignment. Nucleic Acids Res 2019; 47:468-479. [PMID: 30407575 PMCID: PMC6326798 DOI: 10.1093/nar/gky1108] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/22/2018] [Indexed: 12/20/2022] Open
Abstract
The kinetochore is a proteinaceous complex that is essential for proper chromosome segregation. As a core member of the inner kinetochore, defects of each subunit in the CENP-H/I/K complex cause dysfunction of kinetochore that leads to chromosome mis-segregation and cell death. However, how the CENP-H/I/K complex assembles and promotes kinetochore function are poorly understood. We here determined the crystal structures of CENP-I N-terminus alone from Chaetomium thermophilum and its complex with CENP-H/K from Thielavia terrestris, and verified the identified interactions. The structures and biochemical analyses show that CENP-H and CENP-K form a heterodimer through both N- and C-terminal interactions. CENP-I integrates into the CENP-H/K complex by binding to the C-terminus of CENP-H, leading to formation of the ternary complex in which CENP-H is sandwiched between CENP-K and CENP-I. Our sequence comparisons and mutational analyses showed that this architecture of the CENP–H/I/K complex is conserved in human. Mutating the binding interfaces of CENP-H for either CENP-K or CENP-I significantly reduced their localizations at centromeres and induced massive chromosome alignment defects during mitosis, suggesting that the identified interactions are critical for CENP-H/I/K complex assembly at the centromere and kinetochore function. Altogether, our findings unveil the evolutionarily conserved assembly mechanism of the CENP-H/I/K complex that is critical for proper chromosome alignment.
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Affiliation(s)
- Liqiao Hu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hao Huang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Mohan Hei
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yang Yang
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sheng Li
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Yunshan Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhen Dou
- Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Research Center for Physical Sciences at the Microscale, University of Science & Technology of China, Hefei 230027, China
| | - Mengying Wu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jie Li
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Guang-Zhong Wang
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xuebiao Yao
- Anhui Key Laboratory for Cellular Dynamics & Chemical Biology, Hefei National Research Center for Physical Sciences at the Microscale, University of Science & Technology of China, Hefei 230027, China
| | - Hong Liu
- Department of Biochemistry and Molecular Biology, Tulane University Health Science Center, New Orleans, LA 70112, USA
| | - Xiaojing He
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wei Tian
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.,The Institute for Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan 430030, China
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31
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Sharma AB, Dimitrov S, Hamiche A, Van Dyck E. Centromeric and ectopic assembly of CENP-A chromatin in health and cancer: old marks and new tracks. Nucleic Acids Res 2019; 47:1051-1069. [PMID: 30590707 PMCID: PMC6379705 DOI: 10.1093/nar/gky1298] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 12/20/2022] Open
Abstract
The histone H3 variant CENP-A confers epigenetic identity to the centromere and plays crucial roles in the assembly and function of the kinetochore, thus ensuring proper segregation of our chromosomes. CENP-A containing nucleosomes exhibit unique structural specificities and lack the complex profile of gene expression-associated histone posttranslational modifications found in canonical histone H3 and the H3.3 variant. CENP-A mislocalization into noncentromeric regions resulting from its overexpression leads to chromosomal segregation aberrations and genome instability. Overexpression of CENP-A is a feature of many cancers and is associated with malignant progression and poor outcome. The recent years have seen impressive progress in our understanding of the mechanisms that orchestrate CENP-A deposition at native centromeres and ectopic loci. They have witnessed the description of novel, heterotypic CENP-A/H3.3 nucleosome particles and the exploration of the phenotypes associated with the deregulation of CENP-A and its chaperones in tumor cells. Here, we review the structural specificities of CENP-A nucleosomes, the epigenetic features that characterize the centrochromatin and the mechanisms and factors that orchestrate CENP-A deposition at centromeres. We then review our knowledge of CENP-A ectopic distribution, highlighting experimental strategies that have enabled key discoveries. Finally, we discuss the implications of deregulated CENP-A in cancer.
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Affiliation(s)
- Abhishek Bharadwaj Sharma
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health (LIH), 84 Val Fleuri, L-1526 Luxembourg, Luxembourg
| | - Stefan Dimitrov
- Université Grenoble Alpes, CNRS UMR 5309, INSERM U1209, Institute for Advanced Biosciences (IAB), Site Santé-Allée des Alpes, 38700 La Tronche, France.,Izmir Biomedicine and Genome Center, İzmir, Turkey
| | - Ali Hamiche
- Département de Génomique Fonctionnelle et Cancer, Institut de Génétique et Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, CNRS, INSERM, 67404 Illkirch Cedex, France
| | - Eric Van Dyck
- NORLUX Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health (LIH), 84 Val Fleuri, L-1526 Luxembourg, Luxembourg
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32
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Hinshaw SM, Dates AN, Harrison SC. The structure of the yeast Ctf3 complex. eLife 2019; 8:e48215. [PMID: 31194673 PMCID: PMC6602579 DOI: 10.7554/elife.48215] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 06/12/2019] [Indexed: 01/07/2023] Open
Abstract
Kinetochores are the chromosomal attachment points for spindle microtubules. They are also signaling hubs that control major cell cycle transitions and coordinate chromosome folding. Most well-studied eukaryotes rely on a conserved set of factors, which are divided among two loosely-defined groups, for these functions. Outer kinetochore proteins contact microtubules or regulate this contact directly. Inner kinetochore proteins designate the kinetochore assembly site by recognizing a specialized nucleosome containing the H3 variant Cse4/CENP-A. We previously determined the structure, resolved by cryo-electron microscopy (cryo-EM), of the yeast Ctf19 complex (Ctf19c, homologous to the vertebrate CCAN), providing a high-resolution view of inner kinetochore architecture (Hinshaw and Harrison, 2019). We now extend these observations by reporting a near-atomic model of the Ctf3 complex, the outermost Ctf19c sub-assembly seen in our original cryo-EM density. The model is sufficiently well-determined by the new data to enable molecular interpretation of Ctf3 recruitment and function.
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Affiliation(s)
- Stephen M Hinshaw
- Department of Biological Chemistry and Molecular PharmacologyHarvard Medical School, Howard Hughes Medical InstituteBostonUnited States
| | - Andrew N Dates
- Harvard Chemical Biology PhD ProgramHarvard UniversityBostonUnited States
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular PharmacologyHarvard Medical School, Howard Hughes Medical InstituteBostonUnited States
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33
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Remnant L, Booth DG, Vargiu G, Spanos C, Kerr ARW, Earnshaw WC. In vitro BioID: mapping the CENP-A microenvironment with high temporal and spatial resolution. Mol Biol Cell 2019; 30:1314-1325. [PMID: 30892990 PMCID: PMC6724601 DOI: 10.1091/mbc.e18-12-0799] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The centromere is located at the primary constriction of condensed chromosomes where it acts as a platform regulating chromosome segregation. The histone H3 variant CENP-A is the foundation for kinetochore formation. CENP-A directs the formation of a highly dynamic molecular neighborhood whose temporal characterization during mitosis remains a challenge due to limitations in available techniques. BioID is a method that exploits a “promiscuous” biotin ligase (BirA118R or BirA*) to identify proteins within close proximity to a fusion protein of interest. As originally described, cells expressing BirA* fusions were exposed to high biotin concentrations for 24 h during which the ligase transferred activated biotin (BioAmp) to other proteins within the immediate vicinity. The protein neighborhood could then be characterized by streptavidin-based purification and mass spectrometry. Here we describe a further development to this technique, allowing CENP-A interactors to be characterized within only a few minutes, in an in vitro reaction in lysed cells whose physiological progression is “frozen.” This approach, termed in vitro BioID (ivBioID), has the potential to study the molecular neighborhood of any structural protein whose interactions change either during the cell cycle or in response to other changes in cell physiology.
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Affiliation(s)
- Lucy Remnant
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology and
| | - Daniel G Booth
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology and.,Centre for Brain Discovery Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Giulia Vargiu
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology and
| | - Christos Spanos
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology and
| | - Alastair R W Kerr
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology and
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34
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Hinshaw SM, Harrison SC. The structure of the Ctf19c/CCAN from budding yeast. eLife 2019; 8:44239. [PMID: 30762520 PMCID: PMC6407923 DOI: 10.7554/elife.44239] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/13/2019] [Indexed: 12/29/2022] Open
Abstract
Eukaryotic kinetochores connect spindlemicrotubules to chromosomal centromeres. A group of proteins called the Ctf19 complex (Ctf19c) in yeast and the constitutive centromere associated network (CCAN) in other organisms creates the foundation of a kinetochore. The Ctf19c/CCAN influences the timing of kinetochore assembly, sets its location by associating with a specialized nucleosome containing the histone H3 variant Cse4/CENP-A, and determines the organization of the microtubule attachment apparatus. We present here the structure of a reconstituted 13-subunit Ctf19c determined by cryo-electron microscopy at ~4 Å resolution. The structure accounts for known and inferred contacts with the Cse4 nucleosome and for an observed assembly hierarchy. We describe its implications for establishment of kinetochores and for their regulation by kinases throughout the cell cycle.
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Affiliation(s)
- Stephen M Hinshaw
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Howard Hughes Medical Institute, Boston, United States
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Howard Hughes Medical Institute, Boston, United States
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35
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Ferreira LT, Figueiredo AC, Orr B, Lopes D, Maiato H. Dissecting the role of the tubulin code in mitosis. Methods Cell Biol 2018; 144:33-74. [PMID: 29804676 DOI: 10.1016/bs.mcb.2018.03.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitosis is an essential process that takes place in all eukaryotes and involves the equal division of genetic material from a parental cell into two identical daughter cells. During mitosis, chromosome movement and segregation are orchestrated by a specialized structure known as the mitotic spindle, composed of a bipolar array of microtubules. The fundamental structure of microtubules comprises of α/β-tubulin heterodimers that associate head-to-tail and laterally to form hollow filaments. In vivo, microtubules are modified by abundant and evolutionarily conserved tubulin posttranslational modifications (PTMs), giving these filaments the potential for a wide chemical diversity. In recent years, the concept of a "tubulin code" has emerged as an extralayer of regulation governing microtubule function. A range of tubulin isoforms, each with a diverse set of PTMs, provides a readable code for microtubule motors and other microtubule-associated proteins. This chapter focuses on the complexity of tubulin PTMs with an emphasis on detyrosination and summarizes the methods currently used in our laboratory to experimentally manipulate these modifications and study their impact in mitosis.
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Affiliation(s)
- Luísa T Ferreira
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Ana C Figueiredo
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Bernardo Orr
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Danilo Lopes
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Helder Maiato
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
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36
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Abstract
Accurate chromosome segregation critically depends on the formation of attachments between microtubule polymers and each sister chromatid. The kinetochore is the macromolecular complex that assembles at the centromere of each chromosome during mitosis and serves as the link between the DNA and the microtubules. In this Cell Science at a Glance article and accompanying poster, we discuss the activities and molecular players that are involved in generating kinetochore-microtubule attachments, including the initial stages of lateral kinetochore-microtubule interactions and maturation to stabilized end-on attachments. We additionally explore the features that contribute to the ability of the kinetochore to track with dynamic microtubules. Finally, we examine the contributions of microtubule-associated proteins to the organization and stabilization of the mitotic spindle and the control of microtubule dynamics.
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Affiliation(s)
- Julie K Monda
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
- Department of Biology, MIT, Cambridge, MA 02142, USA
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
- Department of Biology, MIT, Cambridge, MA 02142, USA
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37
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Saurin AT. Kinase and Phosphatase Cross-Talk at the Kinetochore. Front Cell Dev Biol 2018; 6:62. [PMID: 29971233 PMCID: PMC6018199 DOI: 10.3389/fcell.2018.00062] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 05/31/2018] [Indexed: 01/26/2023] Open
Abstract
Multiple kinases and phosphatases act on the kinetochore to control chromosome segregation: Aurora B, Mps1, Bub1, Plk1, Cdk1, PP1, and PP2A-B56, have all been shown to regulate both kinetochore-microtubule attachments and the spindle assembly checkpoint. Given that so many kinases and phosphatases converge onto two key mitotic processes, it is perhaps not surprising to learn that they are, quite literally, entangled in cross-talk. Inhibition of any one of these enzymes produces secondary effects on all the others, which results in a complicated picture that is very difficult to interpret. This review aims to clarify this picture by first collating the direct effects of each enzyme into one overarching schematic of regulation at the Knl1/Mis12/Ndc80 (KMN) network (a major signaling hub at the outer kinetochore). This schematic will then be used to discuss the implications of the cross-talk that connects these enzymes; both in terms of why it may be needed to produce the right type of kinetochore signals and why it nevertheless complicates our interpretations about which enzymes control what processes. Finally, some general experimental approaches will be discussed that could help to characterize kinetochore signaling by dissociating the direct from indirect effect of kinase or phosphatase inhibition in vivo. Together, this review should provide a framework to help understand how a network of kinases and phosphatases cooperate to regulate two key mitotic processes.
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Affiliation(s)
- Adrian T. Saurin
- Jacqui Wood Cancer Centre, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
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Jenni S, Dimitrova YN, Valverde R, Hinshaw SM, Harrison SC. Molecular Structures of Yeast Kinetochore Subcomplexes and Their Roles in Chromosome Segregation. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2017; 82:83-89. [PMID: 29167284 DOI: 10.1101/sqb.2017.82.033738] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Kinetochore molecular architecture exemplifies "form follows function." The simplifications that generated the one-chromosome:one-microtubule linkage in point-centromere yeast have enabled strategies for systematic structural analysis and high-resolution visualization of many kinetochore components, leading to specific proposals for molecular mechanisms. We describe here some structural features that allow a kinetochore to remain attached to the end of a depolymerizing microtubule (MT) and some characteristics of the connections between substructures that permit very sensitive regulation by differential kinase activities. We emphasize in particular the importance of flexible connections between rod-like structural members and the integration of these members into a compliant cage-like assembly anchored on the MT by a sliding molecular ring.
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Affiliation(s)
- Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Yoana N Dimitrova
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115.,Howard Hughes Medical Institute, Boston, Massachusetts 02115
| | - Roberto Valverde
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Stephen M Hinshaw
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115.,Howard Hughes Medical Institute, Boston, Massachusetts 02115
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115.,Howard Hughes Medical Institute, Boston, Massachusetts 02115
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