1
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Sako K, Furukawa A, Nozawa RS, Kurita JI, Nishimura Y, Hirota T. Bipartite binding interface recruiting HP1 to chromosomal passenger complex at inner centromeres. J Cell Biol 2024; 223:e202312021. [PMID: 38781028 PMCID: PMC11116813 DOI: 10.1083/jcb.202312021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/05/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024] Open
Abstract
Maintenance of ploidy depends on the mitotic kinase Aurora B, the catalytic subunit of the chromosomal passenger complex (CPC) whose proficient activity is supported by HP1 enriched at inner centromeres. HP1 is known to associate with INCENP of the CPC in a manner that depends on the PVI motif conserved across HP1 interactors. Here, we found that the interaction of INCENP with HP1 requires not only the PVI motif but also its C-terminally juxtaposed domain. Remarkably, these domains conditionally fold the β-strand (PVI motif) and the α-helix from a disordered sequence upon HP1 binding and render INCENP with high affinity to HP1. This bipartite binding domain termed SSH domain (Structure composed of Strand and Helix) is necessary and sufficient to attain a predominant interaction of HP1 with INCENP. These results identify a unique HP1-binding module in INCENP that ensures enrichment of HP1 at inner centromeres, Aurora B activity, and thereby mitotic fidelity.
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Affiliation(s)
- Kosuke Sako
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Ayako Furukawa
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Ryu-Suke Nozawa
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Jun-ichi Kurita
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
| | - Yoshifumi Nishimura
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
| | - Toru Hirota
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan
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2
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Chen L, Qi Q, Jiang X, Wu J, Li Y, Liu Z, Cai Y, Ran H, Zhang S, Zhang C, Wu H, Cao S, Mi L, Xiao D, Huang H, Jiang S, Wu J, Li B, Xie J, Qi J, Li F, Liang P, Han Q, Wu M, Zhou W, Wang C, Zhang W, Jiang X, Zhang K, Li H, Zhang X, Li A, Zhou T, Man J. Phosphocreatine Promotes Epigenetic Reprogramming to Facilitate Glioblastoma Growth Through Stabilizing BRD2. Cancer Discov 2024; 14:1547-1565. [PMID: 38563585 DOI: 10.1158/2159-8290.cd-23-1348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/21/2024] [Accepted: 03/29/2024] [Indexed: 04/04/2024]
Abstract
Glioblastoma (GBM) exhibits profound metabolic plasticity for survival and therapeutic resistance, while the underlying mechanisms remain unclear. Here, we show that GBM stem cells reprogram the epigenetic landscape by producing substantial amounts of phosphocreatine (PCr). This production is attributed to the elevated transcription of brain-type creatine kinase, mediated by Zinc finger E-box binding homeobox 1. PCr inhibits the poly-ubiquitination of the chromatin regulator bromodomain containing protein 2 (BRD2) by outcompeting the E3 ubiquitin ligase SPOP for BRD2 binding. Pharmacological disruption of PCr biosynthesis by cyclocreatine (cCr) leads to BRD2 degradation and a decrease in its targets' transcription, which inhibits chromosome segregation and cell proliferation. Notably, cyclocreatine treatment significantly impedes tumor growth and sensitizes tumors to a BRD2 inhibitor in mouse GBM models without detectable side effects. These findings highlight that high production of PCr is a druggable metabolic feature of GBM and a promising therapeutic target for GBM treatment. Significance: Glioblastoma (GBM) exhibits an adaptable metabolism crucial for survival and therapy resistance. We demonstrate that GBM stem cells modify their epigenetics by producing phosphocreatine (PCr), which prevents bromodomain containing protein 2 (BRD2) degradation and promotes accurate chromosome segregation. Disrupting PCr biosynthesis impedes tumor growth and improves the efficacy of BRD2 inhibitors in mouse GBM models.
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Affiliation(s)
- Lishu Chen
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Qinghui Qi
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Xiaoqing Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Jin Wu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
- Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Yuanyuan Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Zhaodan Liu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Yan Cai
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Haowen Ran
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Songyang Zhang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Cheng Zhang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Huiran Wu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Shuailiang Cao
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Lanjuan Mi
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Dake Xiao
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Haohao Huang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Shuai Jiang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Jiaqi Wu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Bohan Li
- Department of Neurosurgery, Beijing Fengtai Hospital, Beijing, China
| | - Jiong Xie
- Department of Neurosurgery, Beijing Fengtai Hospital, Beijing, China
| | - Ji Qi
- Department of Neurosurgery, Beijing Fengtai Hospital, Beijing, China
| | - Fangye Li
- Department of Neurosurgery, First Medical Center of PLA General Hospital, Beijing, China
| | - Panpan Liang
- Intelligent Pathology Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Qiuying Han
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Min Wu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Wenchao Zhou
- Intelligent Pathology Institute, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Chenhui Wang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Weina Zhang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Xin Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Kun Zhang
- Department of Ultrasound, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Huiyan Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Xuemin Zhang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Ailing Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Tao Zhou
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Jianghong Man
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
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3
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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:e2406009. [PMID: 39018254 DOI: 10.1002/advs.202406009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [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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4
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Zahm JA, Harrison SC. A communication hub for phosphoregulation of kinetochore-microtubule attachment. Curr Biol 2024; 34:2308-2318.e6. [PMID: 38776904 DOI: 10.1016/j.cub.2024.04.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 04/06/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024]
Abstract
The Mps1 and Aurora B kinases regulate and monitor kinetochore attachment to spindle microtubules during cell division, ultimately ensuring accurate chromosome segregation. In yeast, the critical spindle attachment components are the Ndc80 and Dam1 complexes (Ndc80c and DASH/Dam1c, respectively). Ndc80c is a 600-Å-long heterotetramer that binds microtubules through a globular "head" at one end and centromere-proximal kinetochore components through a globular knob at the other end. Dam1c is a heterodecamer that forms a ring of 16-17 protomers around the shaft of the single kinetochore microtubule in point-centromere yeast. The ring coordinates the approximately eight Ndc80c rods per kinetochore. In published work, we showed that a site on the globular "head" of Ndc80c, including residues from both Ndc80 and Nuf2, binds a bipartite segment in the long C-terminal extension of Dam1. Results reported here show, both by in vitro binding experiments and by crystal structure determination, that the same site binds a conserved segment in the long N-terminal extension of Mps1. It also binds, less tightly, a conserved segment in the N-terminal extension of Ipl1 (yeast Aurora B). Together with results from experiments in yeast cells and from biochemical assays reported in two accompanying papers, the structures and graded affinities identify a communication hub for ensuring uniform bipolar attachment and for signaling anaphase onset.
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Affiliation(s)
- Jacob A Zahm
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA.
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5
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Parnell EJ, Jenson EE, Miller MP. A conserved site on Ndc80 complex facilitates dynamic recruitment of Mps1 to yeast kinetochores to promote accurate chromosome segregation. Curr Biol 2024; 34:2294-2307.e4. [PMID: 38776906 PMCID: PMC11178286 DOI: 10.1016/j.cub.2024.04.054] [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: 11/09/2023] [Revised: 03/27/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024]
Abstract
Accurate chromosome segregation relies on kinetochores carrying out multiple functions, including establishing and maintaining microtubule attachments, forming precise bi-oriented attachments between sister chromatids, and activating the spindle assembly checkpoint. Central to these processes is the highly conserved Ndc80 complex. This kinetochore subcomplex interacts directly with microtubules but also serves as a critical platform for recruiting kinetochore-associated factors and as a key substrate for error correction kinases. The precise manner in which these kinetochore factors interact and regulate each other's function remains unknown, considerably hindering our understanding of how Ndc80 complex-dependent processes function together to orchestrate accurate chromosome segregation. Here, we aimed to uncover the role of Nuf2's CH domain, a component of the Ndc80 complex, in ensuring these processes. Through extensive mutational analysis, we identified a conserved interaction domain composed of two segments in Nuf2's CH domain that form the binding site for Mps1 within the yeast Ndc80 complex. Interestingly, this site also associates with the Dam1 complex, suggesting Mps1 recruitment may be subject to regulation by competitive binding with other factors. Mutants disrupting this "interaction hub" exhibit defects in spindle assembly checkpoint function and severe chromosome segregation errors. Significantly, specifically restoring Mps1-Ndc80 complex association rescues these defects. Our findings shed light on the intricate regulation of Ndc80 complex-dependent functions and highlight the essential role of Mps1 in kinetochore bi-orientation and accurate chromosome segregation.
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Affiliation(s)
- Emily J Parnell
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Erin E Jenson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Matthew P Miller
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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6
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Yatskevich S, Yang J, Bellini D, Zhang Z, Barford D. Structure of the human outer kinetochore KMN network complex. Nat Struct Mol Biol 2024; 31:874-883. [PMID: 38459127 PMCID: PMC11189301 DOI: 10.1038/s41594-024-01249-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 02/08/2024] [Indexed: 03/10/2024]
Abstract
Faithful chromosome segregation requires robust, load-bearing attachments of chromosomes to the mitotic spindle, a function accomplished by large macromolecular complexes termed kinetochores. In most eukaryotes, the constitutive centromere-associated network (CCAN) complex of the inner kinetochore recruits to centromeres the ten-subunit outer kinetochore KMN network that comprises the KNL1C, MIS12C and NDC80C complexes. The KMN network directly attaches CCAN to microtubules through MIS12C and NDC80C. Here, we determined a high-resolution cryo-EM structure of the human KMN network. This showed an intricate and extensive assembly of KMN subunits, with the central MIS12C forming rigid interfaces with NDC80C and KNL1C, augmented by multiple peptidic inter-subunit connections. We also observed that unphosphorylated MIS12C exists in an auto-inhibited state that suppresses its capacity to interact with CCAN. Ser100 and Ser109 of the N-terminal segment of the MIS12C subunit Dsn1, two key targets of Aurora B kinase, directly stabilize this auto-inhibition. Our study indicates how selectively relieving this auto-inhibition through Ser100 and Ser109 phosphorylation might restrict outer kinetochore assembly to functional centromeres during cell division.
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Affiliation(s)
- Stanislau Yatskevich
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK.
- Genentech, South San Francisco, CA, USA.
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
| | - Dom Bellini
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, UK.
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7
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Polley S, Raisch T, Ghetti S, Körner M, Terbeck M, Gräter F, Raunser S, Aponte-Santamaría C, Vetter IR, Musacchio A. Structure of the human KMN complex and implications for regulation of its assembly. Nat Struct Mol Biol 2024; 31:861-873. [PMID: 38459128 PMCID: PMC11189300 DOI: 10.1038/s41594-024-01230-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/19/2024] [Indexed: 03/10/2024]
Abstract
Biorientation of chromosomes during cell division is necessary for precise dispatching of a mother cell's chromosomes into its two daughters. Kinetochores, large layered structures built on specialized chromosome loci named centromeres, promote biorientation by binding and sensing spindle microtubules. One of the outer layer main components is a ten-subunit assembly comprising Knl1C, Mis12C and Ndc80C (KMN) subcomplexes. The KMN is highly elongated and docks on kinetochores and microtubules through interfaces at its opposite extremes. Here, we combine cryogenic electron microscopy reconstructions and AlphaFold2 predictions to generate a model of the human KMN that reveals all intra-KMN interfaces. We identify and functionally validate two interaction interfaces that link Mis12C to Ndc80C and Knl1C. Through targeted interference experiments, we demonstrate that this mutual organization strongly stabilizes the KMN assembly. Our work thus reports a comprehensive structural and functional analysis of this part of the kinetochore microtubule-binding machinery and elucidates the path of connections from the chromatin-bound components to the force-generating components.
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Affiliation(s)
- Soumitra Polley
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Tobias Raisch
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Sabrina Ghetti
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Marie Körner
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Melina Terbeck
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
- Max Planck School Matter to Life, Heidelberg, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | | | - Ingrid R Vetter
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
- Max Planck School Matter to Life, Heidelberg, Germany.
- Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany.
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8
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Ouzounidis VR, Green M, van Capelle CDC, Gebhardt C, Crellin H, Finlayson C, Prevo B, Cheerambathur DK. The outer kinetochore components KNL-1 and Ndc80 complex regulate axon and neuronal cell body positioning in the C. elegans nervous system. Mol Biol Cell 2024; 35:ar83. [PMID: 38656792 PMCID: PMC11238089 DOI: 10.1091/mbc.e23-08-0325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024] Open
Abstract
The KMN (Knl1/Mis12/Ndc80) network at the kinetochore, primarily known for its role in chromosome segregation, has been shown to be repurposed during neurodevelopment. Here, we investigate the underlying neuronal mechanism and show that the KMN network promotes the proper axonal organization within the C. elegans head nervous system. Postmitotic degradation of KNL-1, which acts as a scaffold for signaling and has microtubule-binding activities at the kinetochore, led to disorganized ganglia and aberrant placement and organization of axons in the nerve ring - an interconnected axonal network. Through gene-replacement approaches, we demonstrate that the signaling motifs within KNL-1, responsible for recruiting protein phosphatase 1, and activating the spindle assembly checkpoint are required for neurodevelopment. Interestingly, while the microtubule-binding activity is crucial to KMN's neuronal function, microtubule dynamics and organization were unaffected in the absence of KNL-1. Instead, the NDC-80 microtubule-binding mutant displayed notable defects in axon bundling during nerve ring formation, indicating its role in facilitating axon-axon contacts. Overall, these findings provide evidence for a noncanonical role for the KMN network in shaping the structure and connectivity of the nervous system in C. elegans during brain development.
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Affiliation(s)
- Vasileios R. Ouzounidis
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Mattie Green
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Charlotte de Ceuninck van Capelle
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Clara Gebhardt
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Helena Crellin
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Cameron Finlayson
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Bram Prevo
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Dhanya K. Cheerambathur
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
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9
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Kim S, Lau TT, Liao MK, Ma HT, Poon RY. Coregulation of NDC80 Complex Subunits Determines the Fidelity of the Spindle-Assembly Checkpoint and Mitosis. Mol Cancer Res 2024; 22:423-439. [PMID: 38324016 PMCID: PMC11063766 DOI: 10.1158/1541-7786.mcr-23-0828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/07/2023] [Accepted: 02/05/2024] [Indexed: 02/08/2024]
Abstract
NDC80 complex (NDC80C) is composed of four subunits (SPC24, SPC25, NDC80, and NUF2) and is vital for kinetochore-microtubule (KT-MT) attachment during mitosis. Paradoxically, NDC80C also functions in the activation of the spindle-assembly checkpoint (SAC). This raises an interesting question regarding how mitosis is regulated when NDC80C levels are compromised. Using a degron-mediated depletion system, we found that acute silencing of SPC24 triggered a transient mitotic arrest followed by mitotic slippage. SPC24-deficient cells were unable to sustain SAC activation despite the loss of KT-MT interaction. Intriguingly, our results revealed that other subunits of the NDC80C were co-downregulated with SPC24 at a posttranslational level. Silencing any individual subunit of NDC80C likewise reduced the expression of the entire complex. We found that the SPC24-SPC25 and NDC80-NUF2 subcomplexes could be individually stabilized using ectopically expressed subunits. The synergism of SPC24 downregulation with drugs that promote either mitotic arrest or mitotic slippage further underscored the dual roles of NDC80C in KT-MT interaction and SAC maintenance. The tight coordinated regulation of NDC80C subunits suggests that targeting individual subunits could disrupt mitotic progression and provide new avenues for therapeutic intervention. IMPLICATIONS These results highlight the tight coordinated regulation of NDC80C subunits and their potential as targets for antimitotic therapies.
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Affiliation(s)
- Sehong Kim
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Thomas T.Y. Lau
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Man Kit Liao
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Hoi Tang Ma
- Department of Pathology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Liver Research, The University of Hong Kong, Hong Kong
| | - Randy Y.C. Poon
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
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10
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Di Tommaso E, Giunta S. Dynamic interplay between human alpha-satellite DNA structure and centromere functions. Semin Cell Dev Biol 2024; 156:130-140. [PMID: 37926668 DOI: 10.1016/j.semcdb.2023.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/04/2023] [Accepted: 10/10/2023] [Indexed: 11/07/2023]
Abstract
Maintenance of genome stability relies on functional centromeres for correct chromosome segregation and faithful inheritance of the genetic information. The human centromere is the primary constriction within mitotic chromosomes made up of repetitive alpha-satellite DNA hierarchically organized in megabase-long arrays of near-identical higher order repeats (HORs). Centromeres are epigenetically specified by the presence of the centromere-specific histone H3 variant, CENP-A, which enables the assembly of the kinetochore for microtubule attachment. Notably, centromeric DNA is faithfully inherited as intact haplotypes from the parents to the offspring without intervening recombination, yet, outside of meiosis, centromeres are akin to common fragile sites (CFSs), manifesting crossing-overs and ongoing sequence instability. Consequences of DNA changes within the centromere are just starting to emerge, with unclear effects on intra- and inter-generational inheritance driven by centromere's essential role in kinetochore assembly. Here, we review evidence of meiotic selection operating to mitigate centromere drive, as well as recent reports on centromere damage, recombination and repair during the mitotic cell division. We propose an antagonistic pleiotropy interpretation to reconcile centromere DNA instability as both driver of aneuploidy that underlies degenerative diseases, while also potentially necessary for the maintenance of homogenized HORs for centromere function. We attempt to provide a framework for this conceptual leap taking into consideration the structural interface of centromere-kinetochore interaction and present case scenarios for its malfunctioning. Finally, we offer an integrated working model to connect DNA instability, chromatin, and structural changes with functional consequences on chromosome integrity.
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Affiliation(s)
- Elena Di Tommaso
- Laboratory of Genome Evolution, Department of Biology & Biotechnology Charles Darwin, Sapienza University of Rome, Rome 00185, Italy
| | - Simona Giunta
- Laboratory of Genome Evolution, Department of Biology & Biotechnology Charles Darwin, Sapienza University of Rome, Rome 00185, Italy.
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11
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Tarasovetc EV, Sissoko GB, Mukhina AS, Maiorov A, Ataullakhanov FI, Cheeseman IM, Grishchuk EL. Molecular density-accelerated binding-site maturation underlies CENP-T-dependent kinetochore assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.25.581584. [PMID: 38464265 PMCID: PMC10925139 DOI: 10.1101/2024.02.25.581584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Formation of macromolecular cellular structures relies on recruitment of multiple proteins, requiring the precisely controlled pairwise binding interactions. At human kinetochores, our recent work found that the high molecular density environment enables strong bonding between the Ndc80 complex and its two binding sites at the CENP-T receptor. However, the mechanistic basis for this unusual density-dependent facilitation remains unknown. Here, using quantitative single-molecule approaches, we reveal two distinct mechanisms that drive preferential recruitment of the Ndc80 complex to higher-order structures of CENP-T, as opposed to CENP-T monomers. First, the Ndc80 binding sites within the disordered tail of the CENP-T mature over time, leading to a stronger grip on the Spc24/25 heads of the Ndc80 complexes. Second, the maturation of Ndc80 binding sites is accelerated when CENP-T molecules are clustered in close proximity. The rates of the clustering-induced maturation are remarkably different for two binding sites within CENP-T, correlating with different interfaces formed by the corresponding CENP-T sequences as they wrap around the Spc24/25 heads. The differential clustering-dependent regulation of these sites is preserved in dividing human cells, suggesting a distinct regulatory entry point to control kinetochore-microtubule interactions. The tunable acceleration of slowly maturing binding sites by a high molecular-density environment may represent a fundamental physicochemical mechanism to assist the assembly of mitotic kinetochores and other macromolecular structures.
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Affiliation(s)
- Ekaterina V. Tarasovetc
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania; Philadelphia, PA 19104, USA
| | - Gunter B. Sissoko
- Whitehead Institute for Biomedical Research; Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, MA 02142, USA
| | - Anna S. Mukhina
- Department of Physics, Lomonosov Moscow State University; Moscow, 119991, Russia
| | - Aleksandr Maiorov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania; Philadelphia, PA 19104, USA
| | - Fazoil I. Ataullakhanov
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences; Moscow, 119991, Russia
- Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology; Moscow, 117198, Russia
- Moscow Institute of Physics and Technology; 141701, Dolgoprudny, Russia
| | - Iain M. Cheeseman
- Whitehead Institute for Biomedical Research; Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology; Cambridge, MA 02142, USA
| | - Ekaterina L. Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania; Philadelphia, PA 19104, USA
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12
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Kshirsagar R, Munhoven A, Tran Nguyen TM, Ehrenhofer-Murray AE. A role for β-1,6- and β-1,3-glucans in kinetochore function in Saccharomyces cerevisiae. Genetics 2024; 226:iyad195. [PMID: 37950911 PMCID: PMC11221361 DOI: 10.1093/genetics/iyad195] [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: 09/29/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/13/2023] Open
Abstract
Chromosome segregation is crucial for the faithful inheritance of DNA to the daughter cells after DNA replication. For this, the kinetochore, a megadalton protein complex, assembles on centromeric chromatin containing the histone H3 variant CENP-A, and provides a physical connection to the microtubules. Here, we report an unanticipated role for enzymes required for β-1,6- and β-1,3-glucan biosynthesis in regulating kinetochore function in Saccharomyces cerevisiae. These carbohydrates are the major constituents of the yeast cell wall. We found that the deletion of KRE6, which encodes a glycosylhydrolase/ transglycosidase required for β-1,6-glucan synthesis, suppressed the centromeric defect of mutations in components of the kinetochore, foremost the NDC80 components Spc24, Spc25, the MIND component Nsl1, and Okp1, a constitutive centromere-associated network protein. Similarly, the absence of Fks1, a β-1,3-glucan synthase, and Kre11/Trs65, a TRAPPII component, suppressed a mutation in SPC25. Genetic analysis indicates that the reduction of intracellular β-1,6- and β-1,3-glucans, rather than the cell wall glucan content, regulates kinetochore function. Furthermore, we found a physical interaction between Kre6 and CENP-A/Cse4 in yeast, suggesting a potential function for Kre6 in glycosylating CENP-A/Cse4 or another kinetochore protein. This work shows a moonlighting function for selected cell wall synthesis proteins in regulating kinetochore assembly, which may provide a mechanism to connect the nutritional status of the cell to cell-cycle progression and chromosome segregation.
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Affiliation(s)
- Rucha Kshirsagar
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstr. 13, Rhoda-Erdmann-Haus, 10099 Berlin, Germany
| | - Arno Munhoven
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstr. 13, Rhoda-Erdmann-Haus, 10099 Berlin, Germany
| | - Tra My Tran Nguyen
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstr. 13, Rhoda-Erdmann-Haus, 10099 Berlin, Germany
| | - Ann E Ehrenhofer-Murray
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstr. 13, Rhoda-Erdmann-Haus, 10099 Berlin, Germany
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13
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Sissoko GB, Tarasovetc EV, Marescal O, Grishchuk EL, Cheeseman IM. Higher-order protein assembly controls kinetochore formation. Nat Cell Biol 2024; 26:45-56. [PMID: 38168769 PMCID: PMC10842828 DOI: 10.1038/s41556-023-01313-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 11/13/2023] [Indexed: 01/05/2024]
Abstract
To faithfully segregate chromosomes during vertebrate mitosis, kinetochore-microtubule interactions must be restricted to a single site on each chromosome. Prior work on pair-wise kinetochore protein interactions has been unable to identify the mechanisms that prevent outer kinetochore formation in regions with a low density of CENP-A nucleosomes. To investigate the impact of higher-order assembly on kinetochore formation, we generated oligomers of the inner kinetochore protein CENP-T using two distinct, genetically engineered systems in human cells. Although individual CENP-T molecules interact poorly with outer kinetochore proteins, oligomers that mimic centromeric CENP-T density trigger the robust formation of functional, cytoplasmic kinetochore-like particles. Both in cells and in vitro, each molecule of oligomerized CENP-T recruits substantially higher levels of outer kinetochore components than monomeric CENP-T molecules. Our work suggests that the density dependence of CENP-T restricts outer kinetochore recruitment to centromeres, where densely packed CENP-A recruits a high local concentration of inner kinetochore proteins.
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Affiliation(s)
- Gunter B Sissoko
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ekaterina V Tarasovetc
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Océane Marescal
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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14
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Ólafsson G, Haase MAB, Boeke JD. Humanization reveals pervasive incompatibility of yeast and human kinetochore components. G3 (BETHESDA, MD.) 2023; 14:jkad260. [PMID: 37962556 PMCID: PMC10755175 DOI: 10.1093/g3journal/jkad260] [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: 06/29/2023] [Revised: 06/29/2023] [Accepted: 11/06/2023] [Indexed: 11/15/2023]
Abstract
Kinetochores assemble on centromeres to drive chromosome segregation in eukaryotic cells. Humans and budding yeast share most of the structural subunits of the kinetochore, whereas protein sequences have diverged considerably. The conserved centromeric histone H3 variant, CenH3 (CENP-A in humans and Cse4 in budding yeast), marks the site for kinetochore assembly in most species. A previous effort to complement Cse4 in yeast with human CENP-A was unsuccessful; however, co-complementation with the human core nucleosome was not attempted. Previously, our lab successfully humanized the core nucleosome in yeast; however, this severely affected cellular growth. We hypothesized that yeast Cse4 is incompatible with humanized nucleosomes and that the kinetochore represented a limiting factor for efficient histone humanization. Thus, we argued that including the human CENP-A or a Cse4-CENP-A chimera might improve histone humanization and facilitate kinetochore function in humanized yeast. The opposite was true: CENP-A expression reduced histone humanization efficiency, was toxic to yeast, and disrupted cell cycle progression and kinetochore function in wild-type (WT) cells. Suppressors of CENP-A toxicity included gene deletions of subunits of 3 conserved chromatin remodeling complexes, highlighting their role in CenH3 chromatin positioning. Finally, we attempted to complement the subunits of the NDC80 kinetochore complex, individually and in combination, without success, in contrast to a previous study indicating complementation by the human NDC80/HEC1 gene. Our results suggest that limited protein sequence similarity between yeast and human components in this very complex structure leads to failure of complementation.
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Affiliation(s)
- Guðjón Ólafsson
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Max A B Haase
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
- Vilcek Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY 10016, USA
| | - Jef D Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY 14 11201, USA
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15
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Kyriacou E, Heun P. Centromere structure and function: lessons from Drosophila. Genetics 2023; 225:iyad170. [PMID: 37931172 PMCID: PMC10697814 DOI: 10.1093/genetics/iyad170] [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: 06/15/2023] [Accepted: 09/01/2023] [Indexed: 11/08/2023] Open
Abstract
The fruit fly Drosophila melanogaster serves as a powerful model organism for advancing our understanding of biological processes, not just by studying its similarities with other organisms including ourselves but also by investigating its differences to unravel the underlying strategies that evolved to achieve a common goal. This is particularly true for centromeres, specialized genomic regions present on all eukaryotic chromosomes that function as the platform for the assembly of kinetochores. These multiprotein structures play an essential role during cell division by connecting chromosomes to spindle microtubules in mitosis and meiosis to mediate accurate chromosome segregation. Here, we will take a historical perspective on the study of fly centromeres, aiming to highlight not only the important similarities but also the differences identified that contributed to advancing centromere biology. We will discuss the current knowledge on the sequence and chromatin organization of fly centromeres together with advances for identification of centromeric proteins. Then, we will describe both the factors and processes involved in centromere organization and how they work together to provide an epigenetic identity to the centromeric locus. Lastly, we will take an evolutionary point of view of centromeres and briefly discuss current views on centromere drive.
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Affiliation(s)
- Eftychia Kyriacou
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Patrick Heun
- Wellcome Centre of Cell Biology, School of Biological Sciences, University of Edinburgh, EH9 3BF Edinburgh, UK
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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16
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Ariyoshi M, Fukagawa T. An updated view of the kinetochore architecture. Trends Genet 2023; 39:941-953. [PMID: 37775394 DOI: 10.1016/j.tig.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/01/2023] [Accepted: 09/07/2023] [Indexed: 10/01/2023]
Abstract
The kinetochore is a supramolecular complex that facilitates faithful chromosome segregation by bridging the centromere and spindle microtubules. Recent functional and structural studies on the inner kinetochore subcomplex, constitutive centromere-associated network (CCAN) have updated our understanding of kinetochore architecture. While the CCAN core establishes a stable interface with centromeric chromatin, CCAN organization is dynamically altered and coupled with cell cycle progression. Furthermore, the CCAN components, centromere protein (CENP)-C and CENP-T, mediate higher-order assembly of multiple kinetochore units on the regional centromeres of vertebrates. This review highlights new insights into kinetochore rigidity, plasticity, and clustering, which are key to understanding temporal and spatial regulatory mechanisms of chromosome segregation.
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Affiliation(s)
- Mariko Ariyoshi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.
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17
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Parnell EJ, Jenson E, Miller MP. An interaction hub on Ndc80 complex facilitates dynamic recruitment of Mps1 to yeast kinetochores to promote accurate chromosome segregation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.566082. [PMID: 37986816 PMCID: PMC10659343 DOI: 10.1101/2023.11.07.566082] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Accurate chromosome segregation relies on kinetochores carrying out multiple functions, including establishing and maintaining microtubule attachments, forming precise bioriented attachments between sister chromatids, and activating the spindle assembly checkpoint. Central to these processes is the highly conserved Ndc80 complex. This kinetochore subcomplex interacts directly with microtubules, but also serves as a critical platform for recruiting kinetochore-associated factors and as a key substrate for error correction kinases. The precise manner in which these kinetochore factors interact, and regulate each other's function, remains unknown - considerably hindering our understanding of how Ndc80 complex-dependent processes function together to orchestrate accurate chromosome segregation. Here, we aimed to uncover the role of Nuf2's CH domain, a component of the Ndc80 complex, in ensuring accurate chromosome segregation. Through extensive mutational analysis, we identified a conserved "interaction hub" comprising two segments in Nuf2's CH domain, forming the binding site for Mps1 within the yeast Ndc80 complex. Intriguingly, the interaction between Mps1 and the Ndc80 complex seems to be subject to regulation by competitive binding with other factors. Mutants disrupting this interaction hub exhibit defects in spindle assembly checkpoint function and severe chromosome segregation errors. Significantly, specifically restoring Mps1-Ndc80 complex association rescues these defects. Our findings shed light on the intricate regulation of Ndc80 complex-dependent functions and highlight the essential role of Mps1 in kinetochore biorientation and accurate chromosome segregation.
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Affiliation(s)
- Emily J. Parnell
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Erin Jenson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Matthew P. Miller
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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18
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Cimini D. Twenty years of merotelic kinetochore attachments: a historical perspective. Chromosome Res 2023; 31:18. [PMID: 37466740 PMCID: PMC10411636 DOI: 10.1007/s10577-023-09727-7] [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: 05/01/2023] [Revised: 06/20/2023] [Accepted: 07/08/2023] [Indexed: 07/20/2023]
Abstract
Micronuclei, small DNA-containing structures separate from the main nucleus, were used for decades as an indicator of genotoxic damage. Micronuclei containing whole chromosomes were considered a biomarker of aneuploidy and were believed to form, upon mitotic exit, from chromosomes that lagged behind in anaphase as all other chromosomes segregated to the poles of the mitotic spindle. However, the mechanism responsible for inducing anaphase lagging chromosomes remained unknown until just over twenty years ago. Here, I summarize what preceded and what followed this discovery, highlighting some of the open questions and opportunities for future investigation.
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Affiliation(s)
- Daniela Cimini
- Department of Biological Sciences and Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, 24061, USA.
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19
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Pitayu-Nugroho L, Aubry M, Laband K, Geoffroy H, Ganeswaran T, Primadhanty A, Canman JC, Dumont J. Kinetochore component function in C. elegans oocytes revealed by 4D tracking of holocentric chromosomes. Nat Commun 2023; 14:4032. [PMID: 37419936 PMCID: PMC10329006 DOI: 10.1038/s41467-023-39702-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 06/19/2023] [Indexed: 07/09/2023] Open
Abstract
During cell division, chromosome congression to the spindle center, their orientation along the spindle long axis and alignment at the metaphase plate depend on interactions between spindle microtubules and kinetochores, and are pre-requisite for chromosome bi-orientation and accurate segregation. How these successive phases are controlled during oocyte meiosis remains elusive. Here we provide 4D live imaging during the first meiotic division in C. elegans oocytes with wild-type or disrupted kinetochore protein function. We show that, unlike in monocentric organisms, holocentric chromosome bi-orientation is not strictly required for accurate chromosome segregation. Instead, we propose a model in which initial kinetochore-localized BHC module (comprised of BUB-1Bub1, HCP-1/2CENP-F and CLS-2CLASP)-dependent pushing acts redundantly with Ndc80 complex-mediated pulling for accurate chromosome segregation in meiosis. In absence of both mechanisms, homologous chromosomes tend to co-segregate in anaphase, especially when initially mis-oriented. Our results highlight how different kinetochore components cooperate to promote accurate holocentric chromosome segregation in oocytes of C. elegans.
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Affiliation(s)
| | - Mélanie Aubry
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France
| | - Kimberley Laband
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France
| | - Hélène Geoffroy
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France
| | | | | | - Julie C Canman
- Columbia University Irving Medical Center; Department of Pathology and Cell Biology, New York, NY, 10032, USA
| | - Julien Dumont
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013, Paris, France.
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20
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Neblik J, Kirupakaran A, Beuck C, Mieres-Perez J, Niemeyer F, Le MH, Telgheder U, Schmuck JF, Dudziak A, Bayer P, Sanchez-Garcia E, Westermann S, Schrader T. Multivalent Molecular Tweezers Disrupt the Essential NDC80 Interaction with Microtubules. J Am Chem Soc 2023. [PMID: 37392180 DOI: 10.1021/jacs.3c02186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/03/2023]
Abstract
Binding of microtubule filaments by the conserved Ndc80 protein is required for kinetochore-microtubule attachments in cells and the successful distribution of the genetic material during cell division. The reversible inhibition of microtubule binding is an important aspect of the physiological error correction process. Small molecule inhibitors of protein-protein interactions involving Ndc80 are therefore highly desirable, both for mechanistic studies of chromosome segregation and also for their potential therapeutic value. Here, we report on a novel strategy to develop rationally designed inhibitors of the Ndc80 Calponin-homology domain using Supramolecular Chemistry. With a multiple-click approach, lysine-specific molecular tweezers were assembled to form covalently fused dimers to pentamers with a different overall size and preorganization/stiffness. We identified two dimers and a trimer as efficient Ndc80 CH-domain binders and have shown that they disrupt the interaction between Ndc80 and microtubules at low micromolar concentrations without affecting microtubule dynamics. NMR spectroscopy allowed us to identify the biologically important lysine residues 160 and 204 as preferred tweezer interaction sites. Enhanced sampling molecular dynamics simulations provided a rationale for the binding mode of multivalent tweezers and the role of pre-organization and secondary interactions in targeting multiple lysine residues across a protein surface.
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Affiliation(s)
- Jonas Neblik
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Abbna Kirupakaran
- Faculty of Chemistry, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Christine Beuck
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Joel Mieres-Perez
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
- Computational Bioengineering, Faculty of Biochemical and Chemical Engineering, Technical University Dortmund, Dortmund, North Rhine-Westfalia 44227, Germany
| | - Felix Niemeyer
- Faculty of Chemistry, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - My-Hue Le
- Faculty of Chemistry, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Ursula Telgheder
- Faculty of Chemistry, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Jessica Felice Schmuck
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Alexander Dudziak
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Peter Bayer
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Elsa Sanchez-Garcia
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
- Computational Bioengineering, Faculty of Biochemical and Chemical Engineering, Technical University Dortmund, Dortmund, North Rhine-Westfalia 44227, Germany
| | - Stefan Westermann
- Faculty of Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
| | - Thomas Schrader
- Faculty of Chemistry, University of Duisburg-Essen, Essen, North Rhine-Westfalia 45141, Germany
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21
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Amin MA, Chakraborty M, Wallace DA, Varma D. Coordination between the Ndc80 complex and dynein is essential for microtubule plus-end capture by kinetochores during early mitosis. J Biol Chem 2023; 299:104711. [PMID: 37060995 PMCID: PMC10206188 DOI: 10.1016/j.jbc.2023.104711] [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: 10/27/2022] [Revised: 03/22/2023] [Accepted: 04/02/2023] [Indexed: 04/17/2023] Open
Abstract
Mitotic kinetochores are initially captured by dynamic microtubules via a "search-and-capture" mechanism. The microtubule motor, dynein, is critical for kinetochore capture as it has been shown to transport microtubule-attached chromosomes toward the spindle pole during prometaphase. The microtubule-binding nuclear division cycle 80 (Ndc80) complex that is recruited to kinetochores in prophase is known to play a central role in forming kinetochore-microtubule (kMT) attachments in metaphase. It is not yet clear, however, how Ndc80 contributes to initial kMT capture during prometaphase. Here, by combining CRISPR/Cas9-mediated knockout and RNAi technology with assays specific to study kMT capture, we show that mitotic cells lacking Ndc80 exhibit substantial defects in this function during prometaphase. Rescue experiments show that Ndc80 mutants deficient in microtubule-binding are unable to execute proper kMT capture. While cells inhibited of dynein alone are predominantly able to make initial kMT attachments, cells co-depleted of Ndc80 and dynein show severe defects in kMT capture. Further, we use an in vitro total internal reflection fluorescence microscopy assay to reconstitute microtubule capture events, which suggest that Ndc80 and dynein coordinate with each other for microtubule plus-end capture and that the phosphorylation status of Ndc80 is critical for productive kMT capture. A novel interaction between Ndc80 and dynein that we identify in prometaphase extracts might be critical for efficient plus-end capture. Thus, our studies, for the first time, identify a distinct event in the formation of initial kMT attachments, which is directly mediated by Ndc80 and in coordination with dynein is required for efficient kMT capture and chromosome alignment.
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Affiliation(s)
- Mohammed Abdullahel Amin
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
| | - Manas Chakraborty
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Destiny Ariel Wallace
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Dileep Varma
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
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22
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Sobajima T, Kowalczyk KM, Skylakakis S, Hayward D, Fulcher LJ, Neary C, Batley C, Kurlekar S, Roberts E, Gruneberg U, Barr FA. PP6 regulation of Aurora A-TPX2 limits NDC80 phosphorylation and mitotic spindle size. J Cell Biol 2023; 222:e202205117. [PMID: 36897279 PMCID: PMC10041653 DOI: 10.1083/jcb.202205117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 11/22/2022] [Accepted: 02/10/2023] [Indexed: 03/11/2023] Open
Abstract
Amplification of the mitotic kinase Aurora A or loss of its regulator protein phosphatase 6 (PP6) have emerged as drivers of genome instability. Cells lacking PPP6C, the catalytic subunit of PP6, have amplified Aurora A activity, and as we show here, enlarged mitotic spindles which fail to hold chromosomes tightly together in anaphase, causing defective nuclear structure. Using functional genomics to shed light on the processes underpinning these changes, we discover synthetic lethality between PPP6C and the kinetochore protein NDC80. We find that NDC80 is phosphorylated on multiple N-terminal sites during spindle formation by Aurora A-TPX2, exclusively at checkpoint-silenced, microtubule-attached kinetochores. NDC80 phosphorylation persists until spindle disassembly in telophase, is increased in PPP6C knockout cells, and is Aurora B-independent. An Aurora-phosphorylation-deficient NDC80-9A mutant reduces spindle size and suppresses defective nuclear structure in PPP6C knockout cells. In regulating NDC80 phosphorylation by Aurora A-TPX2, PP6 plays an important role in mitotic spindle formation and size control and thus the fidelity of cell division.
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Affiliation(s)
| | | | | | - Daniel Hayward
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, UK
| | - Luke J. Fulcher
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Colette Neary
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Caleb Batley
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Samvid Kurlekar
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Emile Roberts
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Ulrike Gruneberg
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Francis A. Barr
- Department of Biochemistry, University of Oxford, Oxford, UK
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23
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McAinsh AD, Kops GJPL. Principles and dynamics of spindle assembly checkpoint signalling. Nat Rev Mol Cell Biol 2023:10.1038/s41580-023-00593-z. [PMID: 36964313 DOI: 10.1038/s41580-023-00593-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2023] [Indexed: 03/26/2023]
Abstract
The transmission of a complete set of chromosomes to daughter cells during cell division is vital for development and tissue homeostasis. The spindle assembly checkpoint (SAC) ensures correct segregation by informing the cell cycle machinery of potential errors in the interactions of chromosomes with spindle microtubules prior to anaphase. To do so, the SAC monitors microtubule engagement by specialized structures known as kinetochores and integrates local mechanical and chemical cues such that it can signal in a sensitive, responsive and robust manner. In this Review, we discuss how SAC proteins interact to allow production of the mitotic checkpoint complex (MCC) that halts anaphase progression by inhibiting the anaphase-promoting complex/cyclosome (APC/C). We highlight recent advances aimed at understanding the dynamic signalling properties of the SAC and how it interprets various naturally occurring intermediate attachment states. Further, we discuss SAC signalling in the context of the mammalian multisite kinetochore and address the impact of the fibrous corona. We also identify current challenges in understanding how the SAC ensures high-fidelity chromosome segregation.
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Affiliation(s)
- Andrew D McAinsh
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK.
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK.
| | - Geert J P L Kops
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, The Netherlands.
- Oncode Institute, Utrecht, The Netherlands.
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24
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Zahm JA, Jenni S, Harrison SC. Structure of the Ndc80 complex and its interactions at the yeast kinetochore-microtubule interface. Open Biol 2023; 13:220378. [PMID: 36883282 PMCID: PMC9993044 DOI: 10.1098/rsob.220378] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
The conserved Ndc80 kinetochore complex, Ndc80c, is the principal link between mitotic spindle microtubules and centromere-associated proteins. We used AlphaFold 2 (AF2) to obtain predictions of the Ndc80 'loop' structure and of the Ndc80 : Nuf2 globular head domains that interact with the Dam1 subunit of the heterodecameric DASH/Dam1 complex (Dam1c). The predictions guided design of crystallizable constructs, with structures close to the predicted ones. The Ndc80 'loop' is a stiff, α-helical 'switchback' structure; AF2 predictions and positions of preferential cleavage sites indicate that flexibility within the long Ndc80c rod occurs instead at a hinge closer to the globular head. Conserved stretches of the Dam1 C terminus bind Ndc80c such that phosphorylation of Dam1 serine residues 257, 265 and 292 by the mitotic kinase Ipl1/Aurora B can release this contact during error correction of mis-attached kinetochores. We integrate the structural results presented here into our current molecular model of the kinetochore-microtubule interface. The model illustrates how multiple interactions between Ndc80c, DASH/Dam1c and the microtubule lattice stabilize kinetochore attachments.
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Affiliation(s)
- Jacob A. Zahm
- Department of Biological Chemistry and Molecular Pharmacology, and
| | - Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, and
| | - Stephen C. Harrison
- Department of Biological Chemistry and Molecular Pharmacology, and
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
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25
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Deng Y, Li J, Zhang Y, Hu H, Wan F, Min H, Zhou H, Gu L, Liao X, Zhou J, Zhou J. NUF2 Promotes Breast Cancer Development as a New Tumor Stem Cell Indicator. Int J Mol Sci 2023; 24:ijms24044226. [PMID: 36835637 PMCID: PMC9965662 DOI: 10.3390/ijms24044226] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/31/2022] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
Multiple new subtypes of breast cancer (BRCA) are identified in women each year, rendering BRCA the most common and rapidly expanding form of cancer in females globally. NUF2 has been identified as a prognostic factor in various human cancers, regulating cell apoptosis and proliferation. However, its role in BRCA prognosis has not been clarified. This study explored the role of NUF2 in breast cancer development and prognosis using informatic analysis combined with in vivo intracellular studies. Through the online website TIMER, we evaluated the transcription profile of NUF2 across a variety of different cancer types and found that NUF2 mRNA was highly expressed in BRCA patients. Its transcription level was found to be related to the subtype, pathological stage, and prognosis of BRCA. The R program analysis showed a correlation of NUF2 with cell proliferation and tumor stemness in the BRCA patient samples. Subsequently, the association between the NUF2 expression level and immune cell infiltration was analyzed using the XIANTAO and TIMER tools. The results revealed that NUF2 expression was correlated with the responses of multiple immune cells. Furthermore, we observed the effect of NUF2 expression on tumor stemness in BRCA cell lines in vivo. The experimental results illuminated that the overexpression of NUF2 statistically upregulated the proliferation and tumor stemness ability of the BRCA cell lines MCF-7 and Hs-578T. Meanwhile, the knockdown of NUF2 inhibited the abilities of both cell lines, a finding which was verified by analyzing the subcutaneous tumorigenic ability in nude mice. In summary, this study suggests that NUF2 may play a key role in the development and progression of BRCA by affecting tumor stemness. As a stemness indicator, it has the potential to be one of the markers for the diagnosis of BRCA.
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26
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Macaisne N, Bellutti L, Laband K, Edwards F, Pitayu-Nugroho L, Gervais A, Ganeswaran T, Geoffroy H, Maton G, Canman JC, Lacroix B, Dumont J. Synergistic stabilization of microtubules by BUB-1, HCP-1, and CLS-2 controls microtubule pausing and meiotic spindle assembly. eLife 2023; 12:e82579. [PMID: 36799894 PMCID: PMC10005782 DOI: 10.7554/elife.82579] [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: 08/09/2022] [Accepted: 02/16/2023] [Indexed: 02/18/2023] Open
Abstract
During cell division, chromosome segregation is orchestrated by a microtubule-based spindle. Interaction between spindle microtubules and kinetochores is central to the bi-orientation of chromosomes. Initially dynamic to allow spindle assembly and kinetochore attachments, which is essential for chromosome alignment, microtubules are eventually stabilized for efficient segregation of sister chromatids and homologous chromosomes during mitosis and meiosis I, respectively. Therefore, the precise control of microtubule dynamics is of utmost importance during mitosis and meiosis. Here, we study the assembly and role of a kinetochore module, comprised of the kinase BUB-1, the two redundant CENP-F orthologs HCP-1/2, and the CLASP family member CLS-2 (hereafter termed the BHC module), in the control of microtubule dynamics in Caenorhabditis elegans oocytes. Using a combination of in vivo structure-function analyses of BHC components and in vitro microtubule-based assays, we show that BHC components stabilize microtubules, which is essential for meiotic spindle formation and accurate chromosome segregation. Overall, our results show that BUB-1 and HCP-1/2 do not only act as targeting components for CLS-2 at kinetochores, but also synergistically control kinetochore-microtubule dynamics by promoting microtubule pause. Together, our results suggest that BUB-1 and HCP-1/2 actively participate in the control of kinetochore-microtubule dynamics in the context of an intact BHC module to promote spindle assembly and accurate chromosome segregation in meiosis.
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Affiliation(s)
- Nicolas Macaisne
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Laura Bellutti
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Kimberley Laband
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Frances Edwards
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | | | - Alison Gervais
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | | | - Hélène Geoffroy
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Gilliane Maton
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Julie C Canman
- Columbia University; Department of Pathology and Cell BiologyNew YorkUnited States
| | - Benjamin Lacroix
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), CNRS UMR 5237, Université de MontpellierMontpellierFrance
| | - Julien Dumont
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
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27
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Pellegrini FR, De Martino S, Fianco G, Ventura I, Valente D, Fiore M, Trisciuoglio D, Degrassi F. Blockage of autophagosome-lysosome fusion through SNAP29 O-GlcNAcylation promotes apoptosis via ROS production. Autophagy 2023:1-16. [PMID: 36704963 DOI: 10.1080/15548627.2023.2170962] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Macroautophagy/autophagy has been shown to exert a dual role in cancer i.e., promoting cell survival or cell death depending on the cellular context and the cancer stage. Therefore, development of potent autophagy modulators, with a clear mechanistic understanding of their target action, has paramount importance in both mechanistic and clinical studies. In the process of exploring the mechanism of action of a previously identified cytotoxic small molecule (SM15) designed to target microtubules and the interaction domain of microtubules and the kinetochore component NDC80/HEC1, we discovered that the molecule acts as a potent autophagy inhibitor. By using several biochemical and cell biology assays we demonstrated that SM15 blocks basal autophagic flux by inhibiting the fusion of correctly formed autophagosomes with lysosomes. SM15-induced autophagic flux blockage promoted apoptosis-mediated cell death associated with ROS production. Interestingly, autophagic flux blockage, apoptosis induction and ROS production were rescued by genetic or pharmacological inhibition of OGT (O-linked N-acetylglucosamine (GlcNAc) transferase) or by expressing an O-GlcNAcylation-defective mutant of the SNARE fusion complex component SNAP29, pointing to SNAP29 as the molecular target of SM15 in autophagy. Accordingly, SM15 was found to enhance SNAP29 O-GlcNAcylation and, thereby, inhibit the formation of the SNARE fusion complex. In conclusion, these findings identify a new pathway in autophagy connecting O-GlcNAcylated SNAP29 to autophagic flux blockage and autophagosome accumulation, that, in turn, drives ROS production and apoptotic cell death. Consequently, modulation of SNAP29 activity may represent a new opportunity for therapeutic intervention in cancer and other autophagy-associated diseases.
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Affiliation(s)
- Francesca Romana Pellegrini
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Sara De Martino
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Giulia Fianco
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Irene Ventura
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Davide Valente
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Mario Fiore
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Daniela Trisciuoglio
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Francesca Degrassi
- IBPM Institute of Molecular Biology and Pathology, CNR National Research Council, c/o Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
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28
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Radhakrishnan RM, Kizhakkeduth ST, Nair VM, Ayyappan S, Lakshmi RB, Babu N, Prasannajith A, Umeda K, Vijayan V, Kodera N, Manna TK. Kinetochore-microtubule attachment in human cells is regulated by the interaction of a conserved motif of Ska1 with EB1. J Biol Chem 2023; 299:102853. [PMID: 36592928 PMCID: PMC9926122 DOI: 10.1016/j.jbc.2022.102853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 01/02/2023] Open
Abstract
The kinetochore establishes the linkage between chromosomes and the spindle microtubule plus ends during mitosis. In vertebrates, the spindle-kinetochore-associated (Ska1,2,3) complex stabilizes kinetochore attachment with the microtubule plus ends, but how Ska is recruited to and stabilized at the kinetochore-microtubule interface is not understood. Here, our results show that interaction of Ska1 with the general microtubule plus end-associated protein EB1 through a conserved motif regulates Ska recruitment to kinetochores in human cells. Ska1 forms a stable complex with EB1 via interaction with the motif in its N-terminal disordered loop region. Disruption of this interaction either by deleting or mutating the motif disrupts Ska complex recruitment to kinetochores and induces chromosome alignment defects, but it does not affect Ska complex assembly. Atomic-force microscopy imaging revealed that Ska1 is anchored to the C-terminal region of the EB1 dimer through its loop and thereby promotes formation of extended structures. Furthermore, our NMR data showed that the Ska1 motif binds to the residues in EB1 that are the binding sites of other plus end targeting proteins that are recruited to microtubules by EB1 through a similar conserved motif. Collectively, our results demonstrate that EB1-mediated Ska1 recruitment onto the microtubule serves as a general mechanism for the formation of vertebrate kinetochore-microtubule attachments and metaphase chromosome alignment.
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Affiliation(s)
- Renjith M Radhakrishnan
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Safwa T Kizhakkeduth
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Vishnu M Nair
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Shine Ayyappan
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - R Bhagya Lakshmi
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Neethu Babu
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Anjaly Prasannajith
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Kenichi Umeda
- Nano Life Science Institute (WPI-Nano LSI), Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Vinesh Vijayan
- School of Chemistry, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Noriyuki Kodera
- Nano Life Science Institute (WPI-Nano LSI), Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Tapas K Manna
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India.
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29
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Virant D, Vojnovic I, Winkelmeier J, Endesfelder M, Turkowyd B, Lando D, Endesfelder U. Unraveling the kinetochore nanostructure in Schizosaccharomyces pombe using multi-color SMLM imaging. J Cell Biol 2023; 222:213836. [PMID: 36705602 PMCID: PMC9930162 DOI: 10.1083/jcb.202209096] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 12/20/2022] [Accepted: 12/27/2022] [Indexed: 01/28/2023] Open
Abstract
The key to ensuring proper chromosome segregation during mitosis is the kinetochore (KT), a tightly regulated multiprotein complex that links the centromeric chromatin to the spindle microtubules and as such leads the segregation process. Understanding its architecture, function, and regulation is therefore essential. However, due to its complexity and dynamics, only its individual subcomplexes could be studied in structural detail so far. In this study, we construct a nanometer-precise in situ map of the human-like regional KT of Schizosaccharomyces pombe using multi-color single-molecule localization microscopy. We measure each protein of interest (POI) in conjunction with two references, cnp1CENP-A at the centromere and sad1 at the spindle pole. This allows us to determine cell cycle and mitotic plane, and to visualize individual centromere regions separately. We determine protein distances within the complex using Bayesian inference, establish the stoichiometry of each POI and, consequently, build an in situ KT model with unprecedented precision, providing new insights into the architecture.
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Affiliation(s)
- David Virant
- https://ror.org/05r7n9c40Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiologyand LOEWE Center for Synthetic Microbiology, Marburg, Germany
| | - Ilijana Vojnovic
- https://ror.org/05r7n9c40Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiologyand LOEWE Center for Synthetic Microbiology, Marburg, Germany,Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA,Institute for Microbiology and Biotechnology, Rheinische-Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Jannik Winkelmeier
- https://ror.org/05r7n9c40Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiologyand LOEWE Center for Synthetic Microbiology, Marburg, Germany,Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA,Institute for Microbiology and Biotechnology, Rheinische-Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Marc Endesfelder
- https://ror.org/05591te55Institute for Assyriology and Hittitology, Ludwig-Maximilians-Universität München, München, Germany
| | - Bartosz Turkowyd
- https://ror.org/05r7n9c40Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiologyand LOEWE Center for Synthetic Microbiology, Marburg, Germany,Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA,Institute for Microbiology and Biotechnology, Rheinische-Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - David Lando
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Ulrike Endesfelder
- https://ror.org/05r7n9c40Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiologyand LOEWE Center for Synthetic Microbiology, Marburg, Germany,Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA,Institute for Microbiology and Biotechnology, Rheinische-Friedrich-Wilhelms-Universität Bonn, Bonn, Germany,Correspondence to Ulrike Endesfelder:
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30
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Clarke MN, Marsoner T, Adell MAY, Ravichandran MC, Campbell CS. Adaptation to high rates of chromosomal instability and aneuploidy through multiple pathways in budding yeast. EMBO J 2022; 42:e111500. [PMID: 36530167 PMCID: PMC10106982 DOI: 10.15252/embj.2022111500] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 11/08/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
Both an increased frequency of chromosome missegregation (chromosomal instability, CIN) and the presence of an abnormal complement of chromosomes (aneuploidy) are hallmarks of cancer. To better understand how cells are able to adapt to high levels of chromosomal instability, we previously examined yeast cells that were deleted of the gene BIR1, a member of the chromosomal passenger complex (CPC). We found bir1Δ cells quickly adapted by acquiring specific combinations of beneficial aneuploidies. In this study, we monitored these yeast strains for longer periods of time to determine how cells adapt to high levels of both CIN and aneuploidy in the long term. We identify suppressor mutations that mitigate the chromosome missegregation phenotype. The mutated proteins fall into four main categories: outer kinetochore subunits, the SCFCdc4 ubiquitin ligase complex, the mitotic kinase Mps1, and the CPC itself. The identified suppressor mutations functioned by reducing chromosomal instability rather than alleviating the negative effects of aneuploidy. Following the accumulation of suppressor point mutations, the number of beneficial aneuploidies decreased. These experiments demonstrate a time line of adaptation to high rates of CIN.
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Affiliation(s)
- Matthew N Clarke
- Department of Chromosome Biology, Max Perutz Labs, Vienna Biocenter (VBC) University of Vienna Vienna Austria
| | - Theodor Marsoner
- Department of Chromosome Biology, Max Perutz Labs, Vienna Biocenter (VBC) University of Vienna Vienna Austria
| | - Manuel Alonso Y Adell
- Department of Chromosome Biology, Max Perutz Labs, Vienna Biocenter (VBC) University of Vienna Vienna Austria
| | - Madhwesh C Ravichandran
- Department of Chromosome Biology, Max Perutz Labs, Vienna Biocenter (VBC) University of Vienna Vienna Austria
| | - Christopher S Campbell
- Department of Chromosome Biology, Max Perutz Labs, Vienna Biocenter (VBC) University of Vienna Vienna Austria
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31
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Fischer ES. Kinetochore‐catalyzed MCC
formation: A structural perspective. IUBMB Life 2022; 75:289-310. [PMID: 36518060 DOI: 10.1002/iub.2697] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/08/2022] [Indexed: 12/23/2022]
Abstract
The spindle assembly checkpoint (SAC) is a cellular surveillance mechanism that functions to ensure accurate chromosome segregation during mitosis. Macromolecular complexes known as kinetochores, act as the interface of sister chromatid attachment to spindle microtubules. In response to unattached kinetochores, the SAC activates its effector, the mitotic checkpoint complex (MCC), which delays mitotic exit until all sister chromatid pairs have achieved successful attachment to the bipolar mitotic spindle. Formation of the MCC (composed of Mad2, BubR1, Bub3 and Cdc20) is regulated by an Mps1 kinase-dependent phosphorylation signaling cascade which assembles and repositions components of the MCC onto a catalytic scaffold. This scaffold functions to catalyze the conversion of the HORMA-domain protein Mad2 from an "inactive" open-state (O-Mad2) into an "active" closed-Mad2 (C-Mad2), and simultaneous Cdc20 binding. Here, our current understanding of the molecular mechanisms underlying the kinetic barrier to C-Mad2:Cdc20 formation will be reviewed. Recent progress in elucidating the precise molecular choreography orchestrated by the catalytic scaffold to rapidly assemble the MCC will be examined, and unresolved questions will be highlighted. Ultimately, understanding how the SAC rapidly activates the checkpoint not only provides insights into how cells maintain genomic integrity during mitosis, but also provides a paradigm for how cells can utilize molecular switches, including other HORMA domain-containing proteins, to make rapid changes to a cell's physiological state.
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Affiliation(s)
- Elyse S. Fischer
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus Cambridge UK
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32
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Freitag M, Jaklin S, Padovani F, Radzichevici E, Zernia S, Schmoller KM, Stigler J. Single-molecule experiments reveal the elbow as an essential folding guide in SMC coiled-coil arms. Biophys J 2022; 121:4702-4713. [PMID: 36242515 PMCID: PMC9748247 DOI: 10.1016/j.bpj.2022.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/16/2022] [Accepted: 10/12/2022] [Indexed: 11/19/2022] Open
Abstract
Structural maintenance of chromosome (SMC) complexes form ring-like structures through exceptional elongated coiled-coils (CCs). Recent studies found that variable CC conformations, including open and collapsed forms, which might result from discontinuities in the CC, facilitate the diverse functions of SMCs in DNA organization. However, a detailed description of the SMC CC architecture is still missing. Here, we study the structural composition and mechanical properties of SMC proteins with optical tweezers unfolding experiments using the isolated Psm3 CC as a model system. We find a comparatively unstable protein with three unzipping intermediates, which we could directly assign to CC features by crosslinking experiments and state-of-the-art prediction software. Particularly, the CC elbow is shown to be a flexible, potentially non-structured feature, which divides the CC into sections, induces a pairing shift from one CC strand to the other and could facilitate large-scale conformational changes, most likely via thermal fluctuations of the flanking CC sections. A replacement of the elbow amino acids hinders folding of the consecutive CC region and frequently leads to non-native misalignments, revealing the elbow as a guide for proper folding. Additional in vivo manipulation of the elbow flexibility resulted in impaired cohesin complexes, which directly link the sensitive CC architecture to the biological function of cohesin.
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Affiliation(s)
- Marvin Freitag
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sigrun Jaklin
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Francesco Padovani
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Sarah Zernia
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Kurt M Schmoller
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Johannes Stigler
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany.
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33
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Dong Q, Li F. Cell cycle control of kinetochore assembly. Nucleus 2022; 13:208-220. [PMID: 36037227 PMCID: PMC9427032 DOI: 10.1080/19491034.2022.2115246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The kinetochore is a large proteinaceous structure assembled on the centromeres of chromosomes. The complex machinery links chromosomes to the mitotic spindle and is essential for accurate chromosome segregation during cell division. The kinetochore is composed of two submodules: the inner and outer kinetochore. The inner kinetochore is assembled on centromeric chromatin and persists with centromeres throughout the cell cycle. The outer kinetochore attaches microtubules to the inner kinetochore, and assembles only during mitosis. The review focuses on recent advances in our understanding of the mechanisms governing the proper assembly of the outer kinetochore during mitosis and highlights open questions for future investigation.
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Affiliation(s)
- Qianhua Dong
- Department of Biology, New York University, New York, NY, USA
| | - Fei Li
- Department of Biology, New York University, New York, NY, USA
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34
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Geoghegan V, Carnielli JBT, Jones NG, Saldivia M, Antoniou S, Hughes C, Neish R, Dowle A, Mottram JC. CLK1/CLK2-driven signalling at the Leishmania kinetochore is captured by spatially referenced proximity phosphoproteomics. Commun Biol 2022; 5:1305. [PMID: 36437406 PMCID: PMC9701682 DOI: 10.1038/s42003-022-04280-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/18/2022] [Indexed: 11/29/2022] Open
Abstract
Kinetochores in the parasite Leishmania and related kinetoplastids appear to be unique amongst eukaryotes and contain protein kinases as core components. Using the kinetochore kinases KKT2, KKT3 and CLK2 as baits, we developed a BirA* proximity biotinylation methodology optimised for sensitivity, XL-BioID, to investigate the composition and function of the Leishmania kinetochore. We could detect many of the predicted components and also discovered two novel kinetochore proteins, KKT24 and KKT26. Using KKT3 tagged with a fast-acting promiscuous biotin ligase variant, we took proximity biotinylation snapshots of the kinetochore in synchronised parasites. To quantify proximal phosphosites at the kinetochore as the parasite progressed through the cell cycle, we further developed a spatially referenced proximity phosphoproteomics approach. This revealed a group of phosphosites at the kinetochore that were highly dynamic during kinetochore assembly. We show that the kinase inhibitor AB1 targets CLK1/CLK2 (KKT10/KKT19) in Leishmania leading to defective cytokinesis. Using AB1 to uncover CLK1/CLK2 driven signalling pathways important for kinetochore function at G2/M, we found a set of 16 inhibitor responsive kinetochore-proximal phosphosites. Our results exploit new proximity labelling approaches to provide a direct analysis of the Leishmania kinetochore, which is emerging as a promising drug target.
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Affiliation(s)
- Vincent Geoghegan
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Juliana B. T. Carnielli
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Nathaniel G. Jones
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Manuel Saldivia
- grid.418424.f0000 0004 0439 2056Novartis Institute for Tropical Diseases, Emeryville, CA USA
| | - Sergios Antoniou
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Charlotte Hughes
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Rachel Neish
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
| | - Adam Dowle
- grid.5685.e0000 0004 1936 9668Bioscience Technology Facility, Department of Biology, University of York, York, YO10 5DD UK
| | - Jeremy C. Mottram
- grid.5685.e0000 0004 1936 9668York Biomedical Research Institute and Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK
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35
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Matković J, Ghosh S, Ćosić M, Eibes S, Barišić M, Pavin N, Tolić IM. Kinetochore- and chromosome-driven transition of microtubules into bundles promotes spindle assembly. Nat Commun 2022; 13:7307. [PMID: 36435852 PMCID: PMC9701229 DOI: 10.1038/s41467-022-34957-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 11/11/2022] [Indexed: 11/28/2022] Open
Abstract
Mitotic spindle assembly is crucial for chromosome segregation and relies on bundles of microtubules that extend from the poles and overlap in the middle. However, how these structures form remains poorly understood. Here we show that overlap bundles arise through a network-to-bundles transition driven by kinetochores and chromosomes. STED super-resolution microscopy reveals that PRC1-crosslinked microtubules initially form loose arrays, which become rearranged into bundles. Kinetochores promote microtubule bundling by lateral binding via CENP-E/kinesin-7 in an Aurora B-regulated manner. Steric interactions between the bundle-associated chromosomes at the spindle midplane drive bundle separation and spindle widening. In agreement with experiments, theoretical modeling suggests that bundles arise through competing attractive and repulsive mechanisms. Finally, perturbation of overlap bundles leads to inefficient correction of erroneous kinetochore-microtubule attachments. Thus, kinetochores and chromosomes drive coarsening of a uniform microtubule array into overlap bundles, which promote not only spindle formation but also chromosome segregation fidelity.
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Affiliation(s)
- Jurica Matković
- grid.4905.80000 0004 0635 7705Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Subhadip Ghosh
- grid.4808.40000 0001 0657 4636Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Mateja Ćosić
- grid.4905.80000 0004 0635 7705Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Susana Eibes
- grid.417390.80000 0001 2175 6024Cell Division and Cytoskeleton, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Marin Barišić
- grid.417390.80000 0001 2175 6024Cell Division and Cytoskeleton, Danish Cancer Society Research Center, Copenhagen, Denmark ,grid.5254.60000 0001 0674 042XDepartment of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nenad Pavin
- grid.4808.40000 0001 0657 4636Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Iva M. Tolić
- grid.4905.80000 0004 0635 7705Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
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36
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Schwietert F, Volkov VA, Huis In 't Veld PJ, Dogterom M, Musacchio A, Kierfeld J. Strain stiffening of Ndc80 complexes attached to microtubule plus ends. Biophys J 2022; 121:4048-4062. [PMID: 36199251 PMCID: PMC9675032 DOI: 10.1016/j.bpj.2022.09.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/28/2022] [Accepted: 08/27/2022] [Indexed: 11/28/2022] Open
Abstract
In the mitotic spindle, microtubules attach to chromosomes via kinetochores. The microtubule-binding Ndc80 complex is an integral part of kinetochores, and is essential for kinetochores to attach to microtubules and to transmit forces from dynamic microtubule ends to the chromosomes. The Ndc80 complex has a rod-like appearance with globular domains at its ends that are separated by a long coiled coil. Its mechanical properties are considered important for the dynamic interaction between kinetochores and microtubules. Here, we present a novel method that allows us to time trace the effective stiffness of Ndc80 complexes following shortening microtubule ends against applied force in optical trap experiments. Applying this method to wild-type Ndc80 and three variants (calponin homology (CH) domains mutated or Hec1 tail unphosphorylated, phosphorylated, or truncated), we reveal that each variant exhibits strain stiffening; i.e., the effective stiffness increases under tension that is built up by a depolymerizing microtubule. The strain stiffening relation is roughly linear and independent of the state of the microtubule. We introduce structure-based models that show that the strain stiffening can be traced back to the specific architecture of the Ndc80 complex with a characteristic flexible kink, to thermal fluctuations of the microtubule, and to the bending elasticity of flaring protofilaments, which exert force to move the Ndc80 complexes. Our model accounts for changes in the amount of load-bearing attachments at various force levels and reproduces the roughly linear strain stiffening behavior, highlighting the importance of force-dependent binding affinity.
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Affiliation(s)
| | - Vladimir A Volkov
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, UK; Department of Bionanoscience, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands
| | - Pim J Huis In 't Veld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Marileen Dogterom
- Department of Bionanoscience, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Jan Kierfeld
- Physics Department, TU Dortmund University, Dortmund, Germany.
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The augmin complex architecture reveals structural insights into microtubule branching. Nat Commun 2022; 13:5635. [PMID: 36163468 PMCID: PMC9512787 DOI: 10.1038/s41467-022-33228-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
In mitosis, the augmin complex binds to spindle microtubules to recruit the γ-tubulin ring complex (γ-TuRC), the principal microtubule nucleator, for the formation of branched microtubules. Our understanding of augmin-mediated microtubule branching is hampered by the lack of structural information on the augmin complex. Here, we elucidate the molecular architecture and conformational plasticity of the augmin complex using an integrative structural biology approach. The elongated structure of the augmin complex is characterised by extensive coiled-coil segments and comprises two structural elements with distinct but complementary functions in γ-TuRC and microtubule binding, linked by a flexible hinge. The augmin complex is recruited to microtubules via a composite microtubule binding site comprising a positively charged unordered extension and two calponin homology domains. Our study provides the structural basis for augmin function in branched microtubule formation, decisively fostering our understanding of spindle formation in mitosis. The formation of branched microtubule networks in mitotic spindles depends on the augmin complex. Zupa, Würtz et al. elucidate the molecular architecture and conformational plasticity of the augmin complex using integrative structural biology, providing structural insights into microtubule branching.
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Kucharski TJ, Hards R, Vandal SE, Abad MA, Jeyaprakash AA, Kaye E, al-Rawi A, Ly T, Godek KM, Gerber SA, Compton DA. Small changes in phospho-occupancy at the kinetochore-microtubule interface drive mitotic fidelity. J Cell Biol 2022; 221:213364. [PMID: 35878017 PMCID: PMC9351707 DOI: 10.1083/jcb.202107107] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 04/19/2022] [Accepted: 07/05/2022] [Indexed: 01/24/2023] Open
Abstract
Kinetochore protein phosphorylation promotes the correction of erroneous microtubule attachments to ensure faithful chromosome segregation during cell division. Determining how phosphorylation executes error correction requires an understanding of whether kinetochore substrates are completely (i.e., all-or-none) or only fractionally phosphorylated. Using quantitative mass spectrometry (MS), we measured phospho-occupancy on the conserved kinetochore protein Hec1 (NDC80) that directly binds microtubules. None of the positions measured exceeded ∼50% phospho-occupancy, and the cumulative phospho-occupancy changed by only ∼20% in response to changes in microtubule attachment status. The narrow dynamic range of phospho-occupancy is maintained, in part, by the ongoing phosphatase activity. Further, both Cdk1-Cyclin B1 and Aurora kinases phosphorylate Hec1 to enhance error correction in response to different types of microtubule attachment errors. The low inherent phospho-occupancy promotes microtubule attachment to kinetochores while the high sensitivity of kinetochore-microtubule attachments to small changes in phospho-occupancy drives error correction and ensures high mitotic fidelity.
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Affiliation(s)
- Thomas J. Kucharski
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Rufus Hards
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Sarah E. Vandal
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Maria Alba Abad
- Wellcome Centre For Cell Biology, University of Edinburgh, Edinburgh, UK
| | | | - Edward Kaye
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Aymen al-Rawi
- Wellcome Centre For Cell Biology, University of Edinburgh, Edinburgh, UK
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Tony Ly
- Centre for Gene Regulation and Expression, University of Dundee, Dundee, UK
| | - Kristina M. Godek
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH
| | - Scott A. Gerber
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Duane A. Compton
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH
- Correspondence to Duane A. Compton:
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Sridhar S, Fukagawa T. Kinetochore Architecture Employs Diverse Linker Strategies Across Evolution. Front Cell Dev Biol 2022; 10:862637. [PMID: 35800888 PMCID: PMC9252888 DOI: 10.3389/fcell.2022.862637] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 05/23/2022] [Indexed: 01/09/2023] Open
Abstract
The assembly of a functional kinetochore on centromeric chromatin is necessary to connect chromosomes to the mitotic spindle, ensuring accurate chromosome segregation. This connecting function of the kinetochore presents multiple internal and external structural challenges. A microtubule interacting outer kinetochore and centromeric chromatin interacting inner kinetochore effectively confront forces from the external spindle and centromere, respectively. While internally, special inner kinetochore proteins, defined as “linkers,” simultaneously interact with centromeric chromatin and the outer kinetochore to enable association with the mitotic spindle. With the ability to simultaneously interact with outer kinetochore components and centromeric chromatin, linker proteins such as centromere protein (CENP)-C or CENP-T in vertebrates and, additionally CENP-QOkp1-UAme1 in yeasts, also perform the function of force propagation within the kinetochore. Recent efforts have revealed an array of linker pathways strategies to effectively recruit the largely conserved outer kinetochore. In this review, we examine these linkages used to propagate force and recruit the outer kinetochore across evolution. Further, we look at their known regulatory pathways and implications on kinetochore structural diversity and plasticity.
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40
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CellDynaMo–stochastic reaction-diffusion-dynamics model: Application to search-and-capture process of mitotic spindle assembly. PLoS Comput Biol 2022; 18:e1010165. [PMID: 35657997 PMCID: PMC9200364 DOI: 10.1371/journal.pcbi.1010165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 06/15/2022] [Accepted: 05/03/2022] [Indexed: 11/19/2022] Open
Abstract
We introduce a Stochastic Reaction-Diffusion-Dynamics Model (SRDDM) for simulations of cellular mechanochemical processes with high spatial and temporal resolution. The SRDDM is mapped into the CellDynaMo package, which couples the spatially inhomogeneous reaction-diffusion master equation to account for biochemical reactions and molecular transport within the Langevin Dynamics (LD) framework to describe dynamic mechanical processes. This computational infrastructure allows the simulation of hours of molecular machine dynamics in reasonable wall-clock time. We apply SRDDM to test performance of the Search-and-Capture of mitotic spindle assembly by simulating, in three spatial dimensions, dynamic instability of elastic microtubules anchored in two centrosomes, movement and deformations of geometrically realistic centromeres with flexible kinetochores and chromosome arms. Furthermore, the SRDDM describes the mechanics and kinetics of Ndc80 linkers mediating transient attachments of microtubules to the chromosomal kinetochores. The rates of these attachments and detachments depend upon phosphorylation states of the Ndc80 linkers, which are regulated in the model by explicitly accounting for the reactions of Aurora A and B kinase enzymes undergoing restricted diffusion. We find that there is an optimal rate of microtubule-kinetochore detachments which maximizes the accuracy of the chromosome connections, that adding chromosome arms to kinetochores improve the accuracy by slowing down chromosome movements, that Aurora A and kinetochore deformations have a small positive effect on the attachment accuracy, and that thermal fluctuations of the microtubules increase the rates of kinetochore capture and also improve the accuracy of spindle assembly. The CellDynaMo package models, in 3D, any cellular subsystem where sufficient detail of the macromolecular players and the kinetics of relevant reactions are available. The package is based on the Stochastic Reaction-Diffusion-Dynamics model that combines the stochastic description of chemical kinetics, Brownian diffusion-based description of molecular transport, and Langevin dynamics-based representation of mechanical processes most pertinent to the system. We apply the model to test the Search-and-Capture mechanism of mitotic spindle assembly. We find that there is an optimal rate of microtubule-kinetochore detachments which maximizes the accuracy of chromosome connections, that chromosome arms improve the attachment accuracy by slowing down chromosome movements, that Aurora A kinase and kinetochore deformations have small positive effects on the accuracy, and that thermal fluctuations of the microtubules increase the rates of kinetochore capture and also improve the accuracy.
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Hattersley N, Schlientz AJ, Prevo B, Oegema K, Desai A. MEL-28/ELYS and CENP-C coordinately control outer kinetochore assembly and meiotic chromosome-microtubule interactions. Curr Biol 2022; 32:2563-2571.e4. [PMID: 35609608 DOI: 10.1016/j.cub.2022.04.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 03/23/2022] [Accepted: 04/14/2022] [Indexed: 10/18/2022]
Abstract
During mitosis and meiosis in the majority of eukaryotes, centromeric chromatin comprised of CENP-A nucleosomes and their reader CENP-C recruits components of the outer kinetochore to build an interface with spindle microtubules.1,2 One exception is C. elegans oocyte meiosis, where outer kinetochore proteins form cup-like structures on chromosomes independently of centromeric chromatin.3 Here, we show that the nucleoporin MEL-28 (ortholog of human ELYS) and CENP-CHCP-4 act in parallel to recruit outer kinetochore components to oocyte meiotic chromosomes. Unexpectedly, co-inhibition of MEL-28 and CENP-CHCP-4 resulted in chromosomes being expelled from the meiotic spindle prior to anaphase onset, a more severe phenotype than what was observed following ablation of the outer kinetochore.4,5 This observation suggested that MEL-28 and the outer kinetochore independently link chromosomes to spindle microtubules. Consistent with this, the chromosome expulsion defect was observed following co-inhibition of MEL-28 and the microtubule-coupling KNL-1/MIS-12/NDC-80 (KMN) network of the outer kinetochore. Use of engineered mutants showed that MEL-28 acts in conjunction with the microtubule-binding NDC-80 complex to keep chromosomes within the oocyte meiotic spindle and that this function likely involves the Y-complex of nucleoporins that associate with MEL-28; by contrast, the ability to dock protein phosphatase 1, shared by MEL-28 and KNL-1, is not involved. These results highlight nuclear pore-independent functions for a conserved nucleoporin and explain two unusual features of oocyte meiotic chromosome segregation in C. elegans: centromeric chromatin-independent outer kinetochore assembly, and dispensability of the outer kinetochore for constraining chromosomes in the acentrosomal meiotic spindle.
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Affiliation(s)
- Neil Hattersley
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA 92093, USA
| | - Aleesa J Schlientz
- Division of Biological Sciences & Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Bram Prevo
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA 92093, USA
| | - Karen Oegema
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA 92093, USA; Division of Biological Sciences & Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Arshad Desai
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA 92093, USA; Division of Biological Sciences & Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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Zhang C, Zhao S, Tan Y, Pan S, An W, Chen Q, Wang X, Xu H. The SKA3-DUSP2 Axis Promotes Gastric Cancer Tumorigenesis and Epithelial-Mesenchymal Transition by Activating the MAPK/ERK Pathway. Front Pharmacol 2022; 13:777612. [PMID: 35295342 PMCID: PMC8918524 DOI: 10.3389/fphar.2022.777612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 02/11/2022] [Indexed: 12/24/2022] Open
Abstract
Background: Spindle and kinetochore-related complex subunit 3 (SKA3), a member of the SKA family of proteins, is associated with the progression of multiple cancers. However, the role of SKA3 in gastric cancer has not been studied.Methods: The expression levels of SKA3 and dual-specificity phosphatase 2 (DUSP2) proteins were detected by immunohistochemistry. The effects of SKA3 and DUSP2 on the proliferation, migration, invasion, adhesion, and epithelial-mesenchymal transition of gastric cancer were studied in vitro and in vivo.Results: Immunohistochemical analysis of 164 cases of gastric cancer revealed that high expression of SKA3 was negatively correlated with DUSP2 expression and related to N stage, peritoneal metastasis, and poor prognosis. In vitro studies showed that silencing SKA3 expression inhibited the proliferation, migration, invasion, adhesion and epithelial-mesenchymal transition of gastric cancer. In vivo experiments showed that silencing SKA3 inhibited tumor growth and peritoneal metastasis. Mechanistically, SKA3 negative regulates the tumor suppressor DUSP2 and activates the MAPK/ERK pathway to promote gastric cancer.Conclusion: Our results indicate that the SKA3-DUSP2-ERK1/2 axis is involved in the regulation of gastric cancer progression, and SKA3 is a potential therapeutic target for gastric cancer.
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Affiliation(s)
- Chao Zhang
- Department of Gastrointestinal Nutrition and Hernia Surgery, The Second Hospital of Jilin University, Changchun, China
| | - Shutao Zhao
- Department of Gastrointestinal Nutrition and Hernia Surgery, The Second Hospital of Jilin University, Changchun, China
| | - Yuen Tan
- Department of Surgical Oncology, First Affiliated Hospital of China Medical University, Shenyang, China
- Key Laboratory of Gastric Cancer Molecular Pathology of Liaoning Province, Shenyang, China
| | - Siwei Pan
- Department of Surgical Oncology, First Affiliated Hospital of China Medical University, Shenyang, China
- Key Laboratory of Gastric Cancer Molecular Pathology of Liaoning Province, Shenyang, China
| | - Wen An
- Department of Surgical Oncology, First Affiliated Hospital of China Medical University, Shenyang, China
- Key Laboratory of Gastric Cancer Molecular Pathology of Liaoning Province, Shenyang, China
| | - Qingchuan Chen
- Department of Surgical Oncology, First Affiliated Hospital of China Medical University, Shenyang, China
- Key Laboratory of Gastric Cancer Molecular Pathology of Liaoning Province, Shenyang, China
| | - Xudong Wang
- Department of Gastrointestinal Nutrition and Hernia Surgery, The Second Hospital of Jilin University, Changchun, China
- *Correspondence: Xudong Wang, ; Huimian Xu,
| | - Huimian Xu
- Department of Surgical Oncology, First Affiliated Hospital of China Medical University, Shenyang, China
- Key Laboratory of Gastric Cancer Molecular Pathology of Liaoning Province, Shenyang, China
- *Correspondence: Xudong Wang, ; Huimian Xu,
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Barbosa J, Sunkel CE, Conde C. The Role of Mitotic Kinases and the RZZ Complex in Kinetochore-Microtubule Attachments: Doing the Right Link. Front Cell Dev Biol 2022; 10:787294. [PMID: 35155423 PMCID: PMC8832123 DOI: 10.3389/fcell.2022.787294] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/13/2022] [Indexed: 12/31/2022] Open
Abstract
During mitosis, the interaction of kinetochores (KTs) with microtubules (MTs) drives chromosome congression to the spindle equator and supports the segregation of sister chromatids. Faithful genome partition critically relies on the ability of chromosomes to establish and maintain proper amphitelic end-on attachments, a configuration in which sister KTs are connected to robust MT fibers emanating from opposite spindle poles. Because the capture of spindle MTs by KTs is error prone, cells use mechanisms that sense and correct inaccurate KT-MT interactions before committing to segregate sister chromatids in anaphase. If left unresolved, these errors can result in the unequal distribution of chromosomes and lead to aneuploidy, a hallmark of cancer. In this review, we provide an overview of the molecular strategies that monitor the formation and fine-tuning of KT-MT attachments. We describe the complex network of proteins that operates at the KT-MT interface and discuss how AURORA B and PLK1 coordinate several concurrent events so that the stability of KT-MT attachments is precisely modulated throughout mitotic progression. We also outline updated knowledge on how the RZZ complex is regulated to ensure the formation of end-on attachments and the fidelity of mitosis.
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Affiliation(s)
- João Barbosa
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- *Correspondence: João Barbosa, ; Claudio E. Sunkel, ; Carlos Conde,
| | - Claudio E. Sunkel
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
- *Correspondence: João Barbosa, ; Claudio E. Sunkel, ; Carlos Conde,
| | - Carlos Conde
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto, Portugal
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- *Correspondence: João Barbosa, ; Claudio E. Sunkel, ; Carlos Conde,
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Tripathy SK, Demidov VM, Gonchar IV, Wu S, Ataullakhanov FI, Grishchuk EL. Ultrafast Force-Clamp Spectroscopy of Microtubule-Binding Proteins. Methods Mol Biol 2022; 2478:609-650. [PMID: 36063336 PMCID: PMC9662813 DOI: 10.1007/978-1-0716-2229-2_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Optical trapping has been instrumental for deciphering translocation mechanisms of the force-generating cytoskeletal proteins. However, studies of the dynamic interactions between microtubules (MTs) and MT-associated proteins (MAPs) with no motor activity are lagging. Investigating the motility of MAPs that can diffuse along MT walls is a particular challenge for optical-trapping assays because thermally driven motions rely on weak and highly transient interactions. Three-bead, ultrafast force-clamp (UFFC) spectroscopy has the potential to resolve static and diffusive translocations of different MAPs with sub-millisecond temporal resolution and sub-nanometer spatial precision. In this report, we present detailed procedures for implementing UFFC, including setup of the optical instrument and feedback control, immobilization and functionalization of pedestal beads, and preparation of MT dumbbells. Example results for strong static interactions were generated using the Kinesin-7 motor CENP-E in the presence of AMP-PNP. Time resolution for MAP-MT interactions in the UFFC assay is limited by the MT dumbbell relaxation time, which is significantly longer than reported for analogous experiments using actin filaments. UFFC, however, provides a unique opportunity for quantitative studies on MAPs that glide along MTs under a dragging force, as illustrated using the kinetochore-associated Ska complex.
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Affiliation(s)
- Suvranta K Tripathy
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, USA
| | - Vladimir M Demidov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ivan V Gonchar
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Shaowen Wu
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Agro-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Fazly I Ataullakhanov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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45
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Bolanos-Garcia VM. On the Regulation of Mitosis by the Kinetochore, a Macromolecular Complex and Organising Hub of Eukaryotic Organisms. Subcell Biochem 2022; 99:235-267. [PMID: 36151378 DOI: 10.1007/978-3-031-00793-4_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The kinetochore is the multiprotein complex of eukaryotic organisms that is assembled on mitotic or meiotic centromeres to connect centromeric DNA with microtubules. Its function involves the coordinated action of more than 100 different proteins. The kinetochore acts as an organiser hub that establishes physical connections with microtubules and centromere-associated proteins and recruits central protein components of the spindle assembly checkpoint (SAC), an evolutionarily conserved surveillance mechanism of eukaryotic organisms that detects unattached kinetochores and destabilises incorrect kinetochore-microtubule attachments. The molecular communication between the kinetochore and the SAC is highly dynamic and tightly regulated to ensure that cells can progress towards anaphase until each chromosome is properly bi-oriented on the mitotic spindle. This is achieved through an interplay of highly cooperative interactions and concerted phosphorylation/dephosphorylation events that are organised in time and space.This contribution discusses our current understanding of the function, structure and regulation of the kinetochore, in particular, how its communication with the SAC results in the amplification of specific signals to exquisitely control the eukaryotic cell cycle. This contribution also addresses recent advances in machine learning approaches, cell imaging and proteomics techniques that have enhanced our understanding of the molecular mechanisms that ensure the high fidelity and timely segregation of the genetic material every time a cell divides as well as the current challenges in the study of this fascinating molecular machine.
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Affiliation(s)
- Victor M Bolanos-Garcia
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
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46
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Laine LJ, Mäki-Jouppila JHE, Kutvonen E, Tiikkainen P, Nyholm TKM, Tien JF, Umbreit NT, Härmä V, Kallio L, Davis TN, Asbury CL, Poso A, Gorbsky GJ, Kallio MJ. VTT-006, an anti-mitotic compound, binds to the Ndc80 complex and suppresses cancer cell growth in vitro. Oncoscience 2021; 8:134-153. [PMID: 34926718 PMCID: PMC8667816 DOI: 10.18632/oncoscience.549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 12/01/2021] [Indexed: 11/25/2022] Open
Abstract
Hec1 (Highly expressed in cancer 1) resides in the outer kinetochore where it works to facilitate proper kinetochore-microtubule interactions during mitosis. Hec1 is overexpressed in various cancers and its expression shows correlation with high tumour grade and poor patient prognosis. Chemical perturbation of Hec1 is anticipated to impair kinetochore-microtubule binding, activate the spindle assembly checkpoint (spindle checkpoint) and thereby suppress cell proliferation. In this study, we performed high-throughput screen to identify novel small molecules that target the Hec1 calponin homology domain (CHD), which is needed for normal microtubule attachments. 4 million compounds were first virtually fitted against the CHD, and the best hit molecules were evaluated in vitro. These approaches led to the identification of VTT-006, a 1,2-disubstituted-tetrahydro-beta-carboline derivative, which showed binding to recombinant Ndc80 complex and modulated Hec1 association with microtubules in vitro. VTT-006 treatment resulted in chromosome congression defects, reduced chromosome oscillations and induced loss of inter-kinetochore tension. Cells remained arrested in mitosis with an active spindle checkpoint for several hours before undergoing cell death. VTT-006 suppressed the growth of several cancer cell lines and enhanced the sensitivity of HeLa cells to Taxol. Our findings propose that VTT-006 is a potential anti-mitotic compound that disrupts M phase, impairs kinetochore-microtubule interactions, and activates the spindle checkpoint.
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Affiliation(s)
- Leena J Laine
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland.,These authors contributed equally to this work
| | - Jenni H E Mäki-Jouppila
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland.,Drug Research Doctoral Programme, University of Turku, Finland.,Department of Pharmacology, Drug Development and Therapeutics, University of Turku, Turku, Finland.,These authors contributed equally to this work
| | - Emma Kutvonen
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland
| | - Pekka Tiikkainen
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland
| | | | - Jerry F Tien
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Neil T Umbreit
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Ville Härmä
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland
| | - Lila Kallio
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Antti Poso
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Gary J Gorbsky
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Marko J Kallio
- VTT Health, VTT Technical Research Centre of Finland Ltd., Otaniemi, Finland.,Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku 20520, Finland
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47
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Sarangapani KK, Koch LB, Nelson CR, Asbury CL, Biggins S. Kinetochore-bound Mps1 regulates kinetochore-microtubule attachments via Ndc80 phosphorylation. J Cell Biol 2021; 220:e202106130. [PMID: 34647959 PMCID: PMC8641409 DOI: 10.1083/jcb.202106130] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/03/2021] [Accepted: 09/09/2021] [Indexed: 12/22/2022] Open
Abstract
Dividing cells detect and correct erroneous kinetochore-microtubule attachments during mitosis, thereby avoiding chromosome missegregation. The Aurora B kinase phosphorylates microtubule-binding elements specifically at incorrectly attached kinetochores, promoting their release and providing another chance for proper attachments to form. However, growing evidence suggests that the Mps1 kinase is also required for error correction. Here we directly examine how Mps1 activity affects kinetochore-microtubule attachments using a reconstitution-based approach that allows us to separate its effects from Aurora B activity. When endogenous Mps1 that copurifies with kinetochores is activated in vitro, it weakens their attachments to microtubules via phosphorylation of Ndc80, a major microtubule-binding protein. This phosphorylation contributes to error correction because phospho-deficient Ndc80 mutants exhibit genetic interactions and segregation defects when combined with mutants in other error correction pathways. In addition, Mps1 phosphorylation of Ndc80 is stimulated on kinetochores lacking tension. These data suggest that Mps1 provides an additional mechanism for correcting erroneous kinetochore-microtubule attachments, complementing the well-known activity of Aurora B.
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Affiliation(s)
| | - Lori B. Koch
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA
| | - Christian R. Nelson
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Charles L. Asbury
- Department of Physiology & Biophysics, University of Washington, Seattle, WA
| | - Sue Biggins
- Howard Hughes Medical Institute, Chevy Chase, MD
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
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48
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Kroupova A, Ackle F, Asanović I, Weitzer S, Boneberg FM, Faini M, Leitner A, Chui A, Aebersold R, Martinez J, Jinek M. Molecular architecture of the human tRNA ligase complex. eLife 2021; 10:e71656. [PMID: 34854379 PMCID: PMC8668186 DOI: 10.7554/elife.71656] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 12/01/2021] [Indexed: 01/23/2023] Open
Abstract
RtcB enzymes are RNA ligases that play essential roles in tRNA splicing, unfolded protein response, and RNA repair. In metazoa, RtcB functions as part of a five-subunit tRNA ligase complex (tRNA-LC) along with Ddx1, Cgi-99, Fam98B, and Ashwin. The human tRNA-LC or its individual subunits have been implicated in additional cellular processes including microRNA maturation, viral replication, DNA double-strand break repair, and mRNA transport. Here, we present a biochemical analysis of the inter-subunit interactions within the human tRNA-LC along with crystal structures of the catalytic subunit RTCB and the N-terminal domain of CGI-99. We show that the core of the human tRNA-LC is assembled from RTCB and the C-terminal alpha-helical regions of DDX1, CGI-99, and FAM98B, all of which are required for complex integrity. The N-terminal domain of CGI-99 displays structural homology to calponin-homology domains, and CGI-99 and FAM98B associate via their N-terminal domains to form a stable subcomplex. The crystal structure of GMP-bound RTCB reveals divalent metal coordination geometry in the active site, providing insights into its catalytic mechanism. Collectively, these findings shed light on the molecular architecture and mechanism of the human tRNA ligase complex and provide a structural framework for understanding its functions in cellular RNA metabolism.
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Affiliation(s)
- Alena Kroupova
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Fabian Ackle
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Igor Asanović
- Max Perutz Labs, Vienna BioCenter (VBC)ViennaAustria
| | | | | | - Marco Faini
- Department of Biology, Institute of Molecular Systems Biology, ETH ZurichZurichSwitzerland
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, ETH ZurichZurichSwitzerland
| | - Alessia Chui
- Department of Biochemistry, University of ZurichZurichSwitzerland
| | - Ruedi Aebersold
- Department of Biology, Institute of Molecular Systems Biology, ETH ZurichZurichSwitzerland
| | | | - Martin Jinek
- Department of Biochemistry, University of ZurichZurichSwitzerland
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49
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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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50
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Aurora B Tension Sensing Mechanisms in the Kinetochore Ensure Accurate Chromosome Segregation. Int J Mol Sci 2021; 22:ijms22168818. [PMID: 34445523 PMCID: PMC8396173 DOI: 10.3390/ijms22168818] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 11/29/2022] Open
Abstract
The accurate segregation of chromosomes is essential for the survival of organisms and cells. Mistakes can lead to aneuploidy, tumorigenesis and congenital birth defects. The spindle assembly checkpoint ensures that chromosomes properly align on the spindle, with sister chromatids attached to microtubules from opposite poles. Here, we review how tension is used to identify and selectively destabilize incorrect attachments, and thus serves as a trigger of the spindle assembly checkpoint to ensure fidelity in chromosome segregation. Tension is generated on properly attached chromosomes as sister chromatids are pulled in opposing directions but resisted by centromeric cohesin. We discuss the role of the Aurora B kinase in tension-sensing and explore the current models for translating mechanical force into Aurora B-mediated biochemical signals that regulate correction of chromosome attachments to the spindle.
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