1
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Dötsch L, Davies C, Hennes E, Schönfeld J, Kumar A, Guita CDC, Ehrler JH, Hiesinger K, Thavam S, Janning P, Sievers S, Knapp S, Proschak E, Ziegler S, Waldmann H. Discovery of the sEH Inhibitor Epoxykynin as a Potent Kynurenine Pathway Modulator. J Med Chem 2024; 67:4691-4706. [PMID: 38470246 PMCID: PMC10983002 DOI: 10.1021/acs.jmedchem.3c02245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/13/2024]
Abstract
Disease-related phenotypic assays enable unbiased discovery of novel bioactive small molecules and may provide novel insights into physiological systems and unprecedented molecular modes of action (MMOA). Herein, we report the identification and characterization of epoxykynin, a potent inhibitor of the soluble epoxide hydrolase (sEH). Epoxykynin was discovered by means of a cellular assay monitoring modulation of kynurenine (Kyn) levels in BxPC-3 cells upon stimulation with the cytokine interferon-γ (IFN-γ) and subsequent target identification employing affinity-based chemical proteomics. Increased Kyn levels are associated with immune suppression in the tumor microenvironment and, thus, the Kyn pathway and its key player indoleamine 2,3-dioxygenase 1 (IDO1) are appealing targets in immuno-oncology. However, targeting IDO1 directly has led to limited success in clinical investigations, demonstrating that alternative approaches to reduce Kyn levels are in high demand. We uncover a cross-talk between sEH and the Kyn pathway that may provide new opportunities to revert cancer-induced immune tolerance.
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Affiliation(s)
- Lara Dötsch
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
- Department
of Chemical Biology, Technical University
of Dortmund, Otto-Hahn-Strasse
6, Dortmund 44227, Germany
| | - Caitlin Davies
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
| | - Elisabeth Hennes
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
| | - Julia Schönfeld
- Goethe
University Frankfurt, Institute of Pharmaceutical Chemistry, Max-von-Laue-Strasse 9, Frankfurt 60438, Germany
| | - Adarsh Kumar
- Goethe
University Frankfurt, Institute of Pharmaceutical Chemistry, Max-von-Laue-Strasse 9, Frankfurt 60438, Germany
- Structural
Genomics Consortium, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, Frankfurt 60438, Germany
| | - Celine Da Cruz
Lopes Guita
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
| | - Johanna H.M. Ehrler
- Goethe
University Frankfurt, Institute of Pharmaceutical Chemistry, Max-von-Laue-Strasse 9, Frankfurt 60438, Germany
| | - Kerstin Hiesinger
- Goethe
University Frankfurt, Institute of Pharmaceutical Chemistry, Max-von-Laue-Strasse 9, Frankfurt 60438, Germany
| | - Sasikala Thavam
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
| | - Petra Janning
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
| | - Sonja Sievers
- Compound
Management and Screening Center (COMAS), Otto-Hahn-Strasse 15, Dortmund 44227, Germany
| | - Stefan Knapp
- Goethe
University Frankfurt, Institute of Pharmaceutical Chemistry, Max-von-Laue-Strasse 9, Frankfurt 60438, Germany
- Structural
Genomics Consortium, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, Frankfurt 60438, Germany
| | - Ewgenij Proschak
- Goethe
University Frankfurt, Institute of Pharmaceutical Chemistry, Max-von-Laue-Strasse 9, Frankfurt 60438, Germany
| | - Slava Ziegler
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
| | - Herbert Waldmann
- Department
of Chemical Biology, Max Planck Institute
of Molecular Physiology, Otto-Hahn-Strasse 11, Dortmund 44227, Germany
- Department
of Chemical Biology, Technical University
of Dortmund, Otto-Hahn-Strasse
6, Dortmund 44227, Germany
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2
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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 2024:10.1038/s41594-024-01249-y. [PMID: 38459127 DOI: 10.1038/s41594-024-01249-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [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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3
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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 2024:10.1038/s41594-024-01230-9. [PMID: 38459128 DOI: 10.1038/s41594-024-01230-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [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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4
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McGory JM, Verma V, Barcelos DM, Maresca TJ. Multimerization of a disordered kinetochore protein promotes accurate chromosome segregation by localizing a core dynein module. J Cell Biol 2024; 223:e202211122. [PMID: 38180477 PMCID: PMC10770731 DOI: 10.1083/jcb.202211122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 09/06/2023] [Accepted: 12/11/2023] [Indexed: 01/06/2024] Open
Abstract
Kinetochores connect chromosomes and spindle microtubules to maintain genomic integrity through cell division. Crosstalk between the minus-end directed motor dynein and kinetochore-microtubule attachment factors promotes accurate chromosome segregation by a poorly understood pathway. Here, we identify a linkage between the intrinsically disordered protein Spc105 (KNL1 orthologue) and dynein using an optogenetic oligomerization assay. Core pools of the checkpoint protein BubR1 and the adaptor complex RZZ contribute to the linkage. Furthermore, a minimal segment of Spc105 with a propensity to multimerize and which contains protein binding motifs is sufficient to link Spc105 to RZZ/dynein. Deletion of the minimal region from Spc105 compromises the recruitment of its binding partners to kinetochores and elevates chromosome missegregation due to merotelic attachments. Restoration of normal chromosome segregation and localization of BubR1 and RZZ requires both protein binding motifs and oligomerization of Spc105. Together, our results reveal that higher-order multimerization of Spc105 contributes to localizing a core pool of RZZ that promotes accurate chromosome segregation.
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Affiliation(s)
- Jessica M. McGory
- Biology Department, University of Massachusetts, Amherst, MA, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, USA
| | - Vikash Verma
- Biology Department, University of Massachusetts, Amherst, MA, USA
| | | | - Thomas J. Maresca
- Biology Department, University of Massachusetts, Amherst, MA, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, USA
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5
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Fellows BJ, Tolezano GC, Pires SF, Ruegg MSG, Knapp KM, Krepischi ACV, Bicknell LS. A novel KNL1 intronic splicing variant likely destabilizes the KMN complex, causing primary microcephaly. Am J Med Genet A 2024; 194:e63468. [PMID: 37937525 DOI: 10.1002/ajmg.a.63468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/09/2023]
Abstract
Primary microcephaly (MCPH) is an autosomal recessive disorder characterized by head circumference of at least two standard deviations below the mean. Biallelic variants in the kinetochore gene KNL1 is a known cause of MCPH4. KNL1 is the central component of the KNL1-MIS12-NSL1 (KMN) network, which acts as the signaling hub of the kinetochore and is required for correct chromosomal segregation during mitosis. We identified biallelic KNL1 variants in two siblings from a non-consanguineous family with microcephaly and intellectual disability. The two siblings carry a frameshift variant predicted to prematurely truncate the transcript and undergo nonsense mediated decay, and an intronic single nucleotide variant (SNV) predicted to disrupt splicing. An in vitro splicing assay and qPCR from blood-derived RNA confirmed that the intronic variant skips exon 23, significantly reducing levels of the canonical transcript. Protein modeling confirmed that absence of exon 23, an inframe exon, would disrupt a key interaction within the KMN network and likely destabilize the kinetochore signaling hub, disrupting mitosis. Therefore, this splicing variant is pathogenic and, in trans with a frameshift variant, causes the MCPH phenotype associated with KLN1. This finding furthers the association of splicing variants as a common pathogenic variant class for KNL1.
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Affiliation(s)
- Bridget J Fellows
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Giovanna Cantini Tolezano
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, São Paulo, SP, Brazil
| | - Sara Ferreira Pires
- Human Genome and Stem Cell Research Center, Institute of Biosciences, University of São Paulo, São Paulo, SP, Brazil
| | - Mischa S G Ruegg
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Karen M Knapp
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | | | - Louise S Bicknell
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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6
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Deng X, He Y, Tang X, Liu X, Lee YRJ, Liu B, Lin H. A coadapted KNL1 and spindle assembly checkpoint axis orchestrates precise mitosis in Arabidopsis. Proc Natl Acad Sci U S A 2024; 121:e2316583121. [PMID: 38170753 PMCID: PMC10786300 DOI: 10.1073/pnas.2316583121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024] Open
Abstract
The kinetochore scaffold 1 (KNL1) protein recruits spindle assembly checkpoint (SAC) proteins to ensure accurate chromosome segregation during mitosis. Despite such a conserved function among eukaryotic organisms, its molecular architectures have rapidly evolved so that the functional mode of plant KNL1 is largely unknown. To understand how SAC signaling is regulated at kinetochores, we characterized the function of the KNL1 gene in Arabidopsis thaliana. The KNL1 protein was detected at kinetochores throughout the mitotic cell cycle, and null knl1 mutants were viable and fertile but exhibited severe vegetative and reproductive defects. The mutant cells showed serious impairments of chromosome congression and segregation, that resulted in the formation of micronuclei. In the absence of KNL1, core SAC proteins were no longer detected at the kinetochores, and the SAC was not activated by unattached or misaligned chromosomes. Arabidopsis KNL1 interacted with SAC essential proteins BUB3.3 and BMF3 through specific regions that were not found in known KNL1 proteins of other species, and recruited them independently to kinetochores. Furthermore, we demonstrated that upon ectopic expression, the KNL1 homolog from the dicot tomato was able to functionally substitute KNL1 in A. thaliana, while others from the monocot rice or moss associated with kinetochores but were not functional, as reflected by sequence variations of the kinetochore proteins in different plant lineages. Our results brought insights into understanding the rapid evolution and lineage-specific connection between KNL1 and the SAC signaling molecules.
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Affiliation(s)
- Xingguang Deng
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu610064, China
| | - Ying He
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu610064, China
| | - Xiaoya Tang
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu610064, China
| | - Xianghong Liu
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu610064, China
| | - Yuh-Ru Julie Lee
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA95616
| | - Bo Liu
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA95616
| | - Honghui Lin
- Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Sciences, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu610064, China
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7
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Zhou KD, Zhang CX, Niu FR, Bai HC, Wu DD, Deng JC, Qian HY, Jiang YL, Ma W. Exploring Plant Meiosis: Insights from the Kinetochore Perspective. Curr Issues Mol Biol 2023; 45:7974-7995. [PMID: 37886947 PMCID: PMC10605258 DOI: 10.3390/cimb45100504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/12/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023] Open
Abstract
The central player for chromosome segregation in both mitosis and meiosis is the macromolecular kinetochore structure, which is assembled by >100 structural and regulatory proteins on centromere DNA. Kinetochores play a crucial role in cell division by connecting chromosomal DNA and microtubule polymers. This connection helps in the proper segregation and alignment of chromosomes. Additionally, kinetochores can act as a signaling hub, regulating the start of anaphase through the spindle assembly checkpoint, and controlling the movement of chromosomes during anaphase. However, the role of various kinetochore proteins in plant meiosis has only been recently elucidated, and these proteins differ in their functionality from those found in animals. In this review, our current knowledge of the functioning of plant kinetochore proteins in meiosis will be summarized. In addition, the functional similarities and differences of core kinetochore proteins in meiosis between plants and other species are discussed, and the potential applications of manipulating certain kinetochore genes in meiosis for breeding purposes are explored.
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Affiliation(s)
- Kang-Di Zhou
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (K.-D.Z.); (C.-X.Z.)
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Cai-Xia Zhang
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (K.-D.Z.); (C.-X.Z.)
| | - Fu-Rong Niu
- College of Forestry, Gansu Agricultural University, Lanzhou 730070, China;
| | - Hao-Chen Bai
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Dan-Dan Wu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China;
| | - Jia-Cheng Deng
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Hong-Yuan Qian
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Yun-Lei Jiang
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (H.-C.B.); (J.-C.D.); (H.-Y.Q.); (Y.-L.J.)
| | - Wei Ma
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; (K.-D.Z.); (C.-X.Z.)
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8
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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9
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Zhao Y, Yang J, Lu D, Zhu Y, Liao K, Tian Y, Yin R. The Loss-Function of KNL1 Causes Oligospermia and Asthenospermia in Mice by Affecting the Assembly and Separation of the Spindle through Flow Cytometry and Immunofluorescence. Sensors (Basel) 2023; 23:2571. [PMID: 36904774 PMCID: PMC10007211 DOI: 10.3390/s23052571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/13/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
KNL1 (kinetochore scaffold 1) has attracted much attention as one of the assembly elements of the outer kinetochore, and the functions of its different domains have been gradually revealed, most of which are associated with cancers, but few links have been made between KNL1 and male fertility. Here, we first linked KNL1 to male reproductive health and the loss-function of KNL1 resulted in oligospermia and asthenospermia in mice (an 86.5% decrease in total sperm number and an 82.4% increase in static sperm number, respectively) through CASA (computer-aided sperm analysis). Moreover, we introduced an ingenious method to pinpoint the abnormal stage in the spermatogenic cycle using flow cytometry combined with immunofluorescence. Results showed that 49.5% haploid sperm was reduced and 53.2% diploid sperm was increased after the function of KNL1 was lost. Spermatocytes arrest was identified at the meiotic prophase I of spermatogenesis, which was induced by the abnormal assembly and separation of the spindle. In conclusion, we established an association between KNL1 and male fertility, providing a guide for future genetic counseling regarding oligospermia and asthenospermia, and a powerful method for further exploring spermatogenic dysfunction by utilizing flow cytometry and immunofluorescence.
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Affiliation(s)
- Yuwei Zhao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
| | - Jingmin Yang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
- Shanghai WeHealth BioMedical Technology Co., Ltd., Shanghai 201318, China
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
| | - Daru Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
| | - Yijian Zhu
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
| | - Kai Liao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
| | - Yafei Tian
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200000, China
- Shanghai WeHealth BioMedical Technology Co., Ltd., Shanghai 201318, China
| | - Rui Yin
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning Science and Technology Research Institute, Chongqing 404100, China
- Reproductive Medicine Research Center, Medical Research Institute, Southwest University, Chongqing 400715, China
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10
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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11
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Cieslinski K, Wu YL, Nechyporenko L, Hörner SJ, Conti D, Skruzny M, Ries J. Nanoscale structural organization and stoichiometry of the budding yeast kinetochore. J Cell Biol 2023; 222:213833. [PMID: 36705601 PMCID: PMC9929930 DOI: 10.1083/jcb.202209094] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/16/2022] [Accepted: 12/27/2022] [Indexed: 01/28/2023] Open
Abstract
Proper chromosome segregation is crucial for cell division. In eukaryotes, this is achieved by the kinetochore, an evolutionarily conserved multiprotein complex that physically links the DNA to spindle microtubules and takes an active role in monitoring and correcting erroneous spindle-chromosome attachments. Our mechanistic understanding of these functions and how they ensure an error-free outcome of mitosis is still limited, partly because we lack a complete understanding of the kinetochore structure in the cell. In this study, we use single-molecule localization microscopy to visualize individual kinetochore complexes in situ in budding yeast. For major kinetochore proteins, we measured their abundance and position within the metaphase kinetochore. Based on this comprehensive dataset, we propose a quantitative model of the budding yeast kinetochore. While confirming many aspects of previous reports based on bulk imaging, our results present a unifying nanoscale model of the kinetochore in budding yeast.
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Affiliation(s)
- Konstanty Cieslinski
- https://ror.org/03mstc592Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany,Translational Radiation Oncology Unit, Deutsches Krebsforschungszentrum, Heidelberg, Germany
| | - Yu-Le Wu
- https://ror.org/03mstc592Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany,Faculty of Biosciences, Collaboration for Joint PhD Degree Between European Molecular Biology Laboratory and Heidelberg University, Heidelberg, Germany
| | - Lisa Nechyporenko
- https://ror.org/03mstc592Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany,Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Sarah Janice Hörner
- https://ror.org/03mstc592Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany,https://ror.org/04p61dj41Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany,Interdisciplinary Center for Neuroscience, Heidelberg University, Heidelberg, Germany
| | - Duccio Conti
- https://ror.org/03vpj4s62Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Michal Skruzny
- https://ror.org/03mstc592Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jonas Ries
- https://ror.org/03mstc592Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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12
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Smeele PH, Vaccari T. Snapshots from within the cell: Novel trafficking and non trafficking functions of Snap29 during tissue morphogenesis. Semin Cell Dev Biol 2023; 133:42-52. [PMID: 35256275 DOI: 10.1016/j.semcdb.2022.02.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 01/27/2023]
Abstract
Membrane trafficking is a core cellular process that supports diversification of cell shapes and behaviors relevant to morphogenesis during development and in adult organisms. However, how precisely trafficking components regulate specific differentiation programs is incompletely understood. Snap29 is a multifaceted Soluble N-ethylmaleimide-sensitive factor Attachment protein Receptor, involved in a wide range of trafficking and non-trafficking processes in most cells. A body of knowledge, accrued over more than two decades since its discovery, reveals that Snap29 is essential for establishing and maintaining the operation of a number of cellular events that support cell polarity and signaling. In this review, we first summarize established functions of Snap29 and then we focus on novel ones in the context of autophagy, Golgi trafficking and vesicle fusion at the plasma membrane, as well as on non-trafficking activities of Snap29. We further describe emerging evidence regarding the compartmentalisation and regulation of Snap29. Finally, we explore how the loss of distinct functions of human Snap29 may lead to the clinical manifestations of congenital disorders such as CEDNIK syndrome and how altered SNAP29 activity may contribute to the pathogenesis of cancer, viral infection and neurodegenerative diseases.
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Affiliation(s)
- Paulien H Smeele
- Department of Biosciences, Università Degli Studi Di Milano, Milan, Italy
| | - Thomas Vaccari
- Department of Biosciences, Università Degli Studi Di Milano, Milan, Italy.
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13
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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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14
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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15
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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16
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Roy B, Sim J, Han SJY, Joglekar AP. Kre28-Spc105 interaction is essential for Spc105 loading at the kinetochore. Open Biol 2022; 12:210274. [PMID: 35042402 PMCID: PMC8767186 DOI: 10.1098/rsob.210274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Kinetochore (KTs) are macromolecular protein assemblies that attach sister chromatids to spindle microtubules (MTs) and mediate accurate chromosome segregation during mitosis. The outer KT consists of the KMN network, a protein super-complex comprising Knl1 (yeast Spc105), Mis12 (yeast Mtw1), and Ndc80 (yeast Ndc80), which harbours sites for MT binding. Within the KMN network, Spc105 acts as an interaction hub of components involved in spindle assembly checkpoint (SAC) signalling. It is known that Spc105 forms a complex with KT component Kre28. However, where Kre28 physically localizes in the budding yeast KT is not clear. The exact function of Kre28 at the KT is also unknown. Here, we investigate how Spc105 and Kre28 interact and how they are organized within bioriented yeast KTs using genetics and cell biological experiments. Our microscopy data show that Spc105 and Kre28 localize at the KT with a 1 : 1 stoichiometry. We also show that the Kre28-Spc105 interaction is important for Spc105 protein turn-over and essential for their mutual recruitment at the KTs. We created several truncation mutants of kre28 that affect Spc105 loading at the KTs. When over-expressed, these mutants sustain the cell viability, but SAC signalling and KT biorientation are impaired. Therefore, we conclude that Kre28 contributes to chromosome biorientation and high-fidelity segregation at least indirectly by regulating Spc105 localization at the KTs.
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Affiliation(s)
- Babhrubahan Roy
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Janice Sim
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Simon J Y Han
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ajit P Joglekar
- Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
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17
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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Audett MR, Johnson EL, McGory JM, Barcelos DM, Szalai EO, Przewloka MR, Maresca TJ. The microtubule- and PP1-binding activities of Drosophila melanogaster Spc105 control the kinetics of SAC satisfaction. Mol Biol Cell 2022; 33:ar1. [PMID: 34705493 PMCID: PMC8886820 DOI: 10.1091/mbc.e21-06-0307-t] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/31/2021] [Accepted: 10/22/2021] [Indexed: 11/18/2022] Open
Abstract
KNL1 is a large intrinsically disordered kinetochore (KT) protein that recruits spindle assembly checkpoint (SAC) components to mediate SAC signaling. The N-terminal region (NTR) of KNL1 possesses two activities that have been implicated in SAC silencing: microtubule (MT) binding and protein phosphatase 1 (PP1) recruitment. The NTR of Drosophila melanogaster KNL1 (Spc105) has never been shown to bind MTs or to recruit PP1. Furthermore, the phosphoregulatory mechanisms known to control SAC protein binding to KNL1 orthologues is absent in D. melanogaster. Here, these apparent discrepancies are resolved using in vitro and cell-based assays. A phosphoregulatory circuit that utilizes Aurora B kinase promotes SAC protein binding to the central disordered region of Spc105 while the NTR binds directly to MTs in vitro and recruits PP1-87B to KTs in vivo. Live-cell assays employing an optogenetic oligomerization tag and deletion/chimera mutants are used to define the interplay of MT and PP1 binding by Spc105 and the relative contributions of both activities to the kinetics of SAC satisfaction.
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Affiliation(s)
- Margaux R. Audett
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Amherst MA 01003
| | - Erin L. Johnson
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
| | - Jessica M. McGory
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Amherst MA 01003
| | - Dylan M. Barcelos
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
| | - Evelin Oroszne Szalai
- Institute for Life Sciences, School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Marcin R. Przewloka
- Institute for Life Sciences, School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Thomas J. Maresca
- Biology Department, University of Massachusetts, Amherst, Amherst MA 01003
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Amherst MA 01003
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19
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Zhang M, Yang F, Wang W, Wang X, Wang D, Dou Z, Song X, Liu X, Yao X. SKAP interacts with Aurora B to guide end-on capture of spindle microtubules via phase separation. J Mol Cell Biol 2021; 13:841-852. [PMID: 34554241 PMCID: PMC8800532 DOI: 10.1093/jmcb/mjab058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/15/2021] [Accepted: 06/21/2021] [Indexed: 11/18/2022] Open
Abstract
Chromosome segregation in mitosis is orchestrated by the dynamic interactions between the kinetochore and spindle microtubules. Our recent studies show that mitotic motor CENP-E cooperates with SKAP and forms a link between kinetochore core MIS13 complex and spindle microtubule plus-ends to achieve accurate chromosome alignment in mitosis. However, it remains elusive how SKAP regulates kinetochore attachment from lateral association to end-on attachment during metaphase alignment. Here, we identify a novel interaction between Aurora B and SKAP that orchestrates accurate interaction between the kinetochore and dynamic spindle microtubules. Interestingly, SKAP spontaneously phase-separates in vitro via weak, multivalent interactions into droplets with fast internal dynamics. SKAP and Aurora B form heterogeneous coacervates in vitro, which recapitulate the dynamics and behavior of SKAP comets in vivo. Importantly, SKAP interaction with Aurora B via phase separation is essential for accurate chromosome segregation and alignment. Based on those findings, we reason that SKAP–Aurora B interaction via phase separation constitutes a dynamic pool of Aurora B activity during the lateral to end-on conversion of kinetochore–microtubule attachments to achieve faithful cell division.
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Affiliation(s)
- Manjuan Zhang
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China.,Anhui Key Laboratory for Cellular Dynamics & Chemical Biology and CAS Center for Excellence in Molecular Cell Science, Hefei 230027, China
| | - Fengrui Yang
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China.,Anhui Key Laboratory for Cellular Dynamics & Chemical Biology and CAS Center for Excellence in Molecular Cell Science, Hefei 230027, China.,Keck Center for Organoids Plasticity Control, Atlanta, GA 30310, USA
| | - Wenwen Wang
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China.,Keck Center for Organoids Plasticity Control, Atlanta, GA 30310, USA
| | - Xiwei Wang
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China.,Anhui Key Laboratory for Cellular Dynamics & Chemical Biology and CAS Center for Excellence in Molecular Cell Science, Hefei 230027, China.,Keck Center for Organoids Plasticity Control, Atlanta, GA 30310, USA
| | - Dongmei Wang
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China.,Anhui Key Laboratory for Cellular Dynamics & Chemical Biology and CAS Center for Excellence in Molecular Cell Science, Hefei 230027, China.,Keck Center for Organoids Plasticity Control, Atlanta, GA 30310, USA
| | - Zhen Dou
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China.,Anhui Key Laboratory for Cellular Dynamics & Chemical Biology and CAS Center for Excellence in Molecular Cell Science, Hefei 230027, China
| | - Xiaoyu Song
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China.,Anhui Key Laboratory for Cellular Dynamics & Chemical Biology and CAS Center for Excellence in Molecular Cell Science, Hefei 230027, China.,Keck Center for Organoids Plasticity Control, Atlanta, GA 30310, USA
| | - Xing Liu
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China
| | - Xuebiao Yao
- MOE Key Laboratory for Cellular Dynamics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230027, China
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20
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Kumon T, Ma J, Akins RB, Stefanik D, Nordgren CE, Kim J, Levine MT, Lampson MA. Parallel pathways for recruiting effector proteins determine centromere drive and suppression. Cell 2021; 184:4904-4918.e11. [PMID: 34433012 PMCID: PMC8448984 DOI: 10.1016/j.cell.2021.07.037] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 06/07/2021] [Accepted: 07/29/2021] [Indexed: 12/19/2022]
Abstract
Selfish centromere DNA sequences bias their transmission to the egg in female meiosis. Evolutionary theory suggests that centromere proteins evolve to suppress costs of this "centromere drive." In hybrid mouse models with genetically different maternal and paternal centromeres, selfish centromere DNA exploits a kinetochore pathway to recruit microtubule-destabilizing proteins that act as drive effectors. We show that such functional differences are suppressed by a parallel pathway for effector recruitment by heterochromatin, which is similar between centromeres in this system. Disrupting the kinetochore pathway with a divergent allele of CENP-C reduces functional differences between centromeres, whereas disrupting heterochromatin by CENP-B deletion amplifies the differences. Molecular evolution analyses using Murinae genomes identify adaptive evolution in proteins in both pathways. We propose that centromere proteins have recurrently evolved to minimize the kinetochore pathway, which is exploited by selfish DNA, relative to the heterochromatin pathway that equalizes centromeres, while maintaining essential functions.
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Affiliation(s)
- Tomohiro Kumon
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jun Ma
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - R Brian Akins
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Derek Stefanik
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - C Erik Nordgren
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Junhyong Kim
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mia T Levine
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael A Lampson
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA.
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21
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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22
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Abstract
The tremendous diversity in eukaryotic life forms can ultimately be traced back to evolutionary modifications at the level of molecular networks. Deep understanding of these modifications will not only explain cellular diversity, but will also uncover different ways to execute similar processes and expose the evolutionary 'rules' that shape the molecular networks. Here, we review the evolutionary dynamics of the spindle assembly checkpoint (SAC), a signaling network that guards fidelity of chromosome segregation. We illustrate how the interpretation of divergent SAC systems in eukaryotic species is facilitated by combining detailed molecular knowledge of the SAC and extensive comparative genome analyses. Ultimately, expanding this to other core cellular systems and experimentally interrogating such systems in organisms from all major lineages may start outlining the routes to and eventual manifestation of the cellular diversity of eukaryotic life.
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Affiliation(s)
- Geert J P L Kops
- Oncode Institute, Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, The Netherlands.
| | - Berend Snel
- Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands.
| | - Eelco C Tromer
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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23
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Li J, Wang Y, Zou W, Jian L, Fu Y, Zhao J. AtNUF2 modulates spindle microtubule organization and chromosome segregation during mitosis. Plant J 2021; 107:801-816. [PMID: 33993566 DOI: 10.1111/tpj.15347] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 05/08/2021] [Accepted: 05/10/2021] [Indexed: 06/12/2023]
Abstract
The NDC80 complex is a conserved eukaryotic complex composed of four subunits (NUF2, SPC25, NDC80, and SPC24). In yeast and animal cells, the complex is located at the outer layer of the kinetochore, connecting the inner layer of the kinetochore and spindle microtubules (MTs) during cell division. In higher plants, the relationship of the NDC80 complex with MTs is still unclear. In this study, we characterized the biological function of AtNUF2, a subunit of the Arabidopsis NDC80 complex. We found that AtNUF2 is widely expressed in various organs, especially in different stages of embryonic development. It was verified that AtNUF2 co-localized with α-tubulin on MTs during mitosis by immunohistochemical assays. Mutation of AtNUF2 led to severe mitotic defects, not only in the embryo and endosperm, but also in seedlings, resulting in seed abortion and stagnating seedling growth. Furthermore, the biological function of AtNUF2 was studied using partially complemented nuf2-3/-DD45;ABI3pro::AtNUF2 (nuf2-3/-DA ) seedlings. The chromosome bridge and lagging chromatids occurred in nuf2-3/-DA root apical meristem cells, along with aberration of spindle MTs, resulting in blocked root growth. Meanwhile, the direct binding of AtNUF2 and AtSPC25 to MTs was determined by an MT co-sedimentation assay in vitro. This study revealed the function of AtNUF2 in mitosis and the underlying mechanisms, modulating spindle MT organization and ensuring chromosome segregation during embryo, endosperm, and root development, laying the foundation for subsequent research of the NDC80 complex.
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Affiliation(s)
- Jin Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yutao Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wenxuan Zou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Liufang Jian
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Ying Fu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China
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24
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Fischer ES, Yu CWH, Bellini D, McLaughlin SH, Orr CM, Wagner A, Freund SMV, Barford D. Molecular mechanism of Mad1 kinetochore targeting by phosphorylated Bub1. EMBO Rep 2021; 22:e52242. [PMID: 34013668 PMCID: PMC8391104 DOI: 10.15252/embr.202052242] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/02/2021] [Accepted: 04/13/2021] [Indexed: 01/10/2023] Open
Abstract
During metaphase, in response to improper kinetochore-microtubule attachments, the spindle assembly checkpoint (SAC) activates the mitotic checkpoint complex (MCC), an inhibitor of the anaphase-promoting complex/cyclosome (APC/C). This process is orchestrated by the kinase Mps1, which initiates the assembly of the MCC onto kinetochores through a sequential phosphorylation-dependent signalling cascade. The Mad1-Mad2 complex, which is required to catalyse MCC formation, is targeted to kinetochores through a direct interaction with the phosphorylated conserved domain 1 (CD1) of Bub1. Here, we present the crystal structure of the C-terminal domain of Mad1 (Mad1CTD ) bound to two phosphorylated Bub1CD1 peptides at 1.75 Å resolution. This interaction is mediated by phosphorylated Bub1 Thr461, which not only directly interacts with Arg617 of the Mad1 RLK (Arg-Leu-Lys) motif, but also directly acts as an N-terminal cap to the CD1 α-helix dipole. Surprisingly, only one Bub1CD1 peptide binds to the Mad1 homodimer in solution. We suggest that this stoichiometry is due to inherent asymmetry in the coiled-coil of Mad1CTD and has implications for how the Mad1-Bub1 complex at kinetochores promotes efficient MCC assembly.
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Affiliation(s)
| | | | - Dom Bellini
- MRC Laboratory of Molecular BiologyCambridgeUK
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25
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De la Fuente IM, Martínez L, Carrasco-Pujante J, Fedetz M, López JI, Malaina I. Self-Organization and Information Processing: From Basic Enzymatic Activities to Complex Adaptive Cellular Behavior. Front Genet 2021; 12:644615. [PMID: 34093645 PMCID: PMC8176287 DOI: 10.3389/fgene.2021.644615] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/16/2021] [Indexed: 11/13/2022] Open
Abstract
One of the main aims of current biology is to understand the origin of the molecular organization that underlies the complex dynamic architecture of cellular life. Here, we present an overview of the main sources of biomolecular order and complexity spanning from the most elementary levels of molecular activity to the emergence of cellular systemic behaviors. First, we have addressed the dissipative self-organization, the principal source of molecular order in the cell. Intensive studies over the last four decades have demonstrated that self-organization is central to understand enzyme activity under cellular conditions, functional coordination between enzymatic reactions, the emergence of dissipative metabolic networks (DMN), and molecular rhythms. The second fundamental source of order is molecular information processing. Studies on effective connectivity based on transfer entropy (TE) have made possible the quantification in bits of biomolecular information flows in DMN. This information processing enables efficient self-regulatory control of metabolism. As a consequence of both main sources of order, systemic functional structures emerge in the cell; in fact, quantitative analyses with DMN have revealed that the basic units of life display a global enzymatic structure that seems to be an essential characteristic of the systemic functional metabolism. This global metabolic structure has been verified experimentally in both prokaryotic and eukaryotic cells. Here, we also discuss how the study of systemic DMN, using Artificial Intelligence and advanced tools of Statistic Mechanics, has shown the emergence of Hopfield-like dynamics characterized by exhibiting associative memory. We have recently confirmed this thesis by testing associative conditioning behavior in individual amoeba cells. In these Pavlovian-like experiments, several hundreds of cells could learn new systemic migratory behaviors and remember them over long periods relative to their cell cycle, forgetting them later. Such associative process seems to correspond to an epigenetic memory. The cellular capacity of learning new adaptive systemic behaviors represents a fundamental evolutionary mechanism for cell adaptation.
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Affiliation(s)
- Ildefonso M. De la Fuente
- Department of Nutrition, CEBAS-CSIC Institute, Murcia, Spain
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Luis Martínez
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
- Basque Center of Applied Mathematics (BCAM), Bilbao, Spain
| | - Jose Carrasco-Pujante
- Department of Cell Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Maria Fedetz
- Department of Cell Biology and Immunology, Institute of Parasitology and Biomedicine “López-Neyra”, CSIC, Granada, Spain
| | - José I. López
- Department of Pathology, Cruces University Hospital, Biocruces-Bizkaia Health Research Institute, Barakaldo, Spain
| | - Iker Malaina
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
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26
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Singh P, Pesenti ME, Maffini S, Carmignani S, Hedtfeld M, Petrovic A, Srinivasamani A, Bange T, Musacchio A. BUB1 and CENP-U, Primed by CDK1, Are the Main PLK1 Kinetochore Receptors in Mitosis. Mol Cell 2021; 81:67-87.e9. [PMID: 33248027 PMCID: PMC7837267 DOI: 10.1016/j.molcel.2020.10.040] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 09/08/2020] [Accepted: 10/28/2020] [Indexed: 02/02/2023]
Abstract
Reflecting its pleiotropic functions, Polo-like kinase 1 (PLK1) localizes to various sub-cellular structures during mitosis. At kinetochores, PLK1 contributes to microtubule attachments and mitotic checkpoint signaling. Previous studies identified a wealth of potential PLK1 receptors at kinetochores, as well as requirements for various mitotic kinases, including BUB1, Aurora B, and PLK1 itself. Here, we combine ectopic localization, in vitro reconstitution, and kinetochore localization studies to demonstrate that most and likely all of the PLK1 is recruited through BUB1 in the outer kinetochore and centromeric protein U (CENP-U) in the inner kinetochore. BUB1 and CENP-U share a constellation of sequence motifs consisting of a putative PP2A-docking motif and two neighboring PLK1-docking sites, which, contingent on priming phosphorylation by cyclin-dependent kinase 1 and PLK1 itself, bind PLK1 and promote its dimerization. Our results rationalize previous observations and describe a unifying mechanism for recruitment of PLK1 to human kinetochores.
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Affiliation(s)
- Priyanka Singh
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Marion E Pesenti
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Stefano Maffini
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Sara Carmignani
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Marius Hedtfeld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Arsen Petrovic
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Anupallavi Srinivasamani
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Tanja Bange
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany; Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstrasse, 45141 Essen, Germany.
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27
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Ghodgaonkar-Steger M, Potocnjak M, Zimniak T, Fischböck-Halwachs J, Solis-Mezarino V, Singh S, Speljko T, Hagemann G, Drexler DJ, Witte G, Herzog F. C-Terminal Motifs of the MTW1 Complex Cooperatively Stabilize Outer Kinetochore Assembly in Budding Yeast. Cell Rep 2020; 32:108190. [PMID: 32997987 DOI: 10.1016/j.celrep.2020.108190] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 07/18/2020] [Accepted: 09/01/2020] [Indexed: 12/01/2022] Open
Abstract
Kinetochores are macromolecular protein assemblies at centromeres that mediate accurate chromosome segregation during cell division. The outer kinetochore KNL1SPC105, MIS12MTW1, and NDC80NDC80 complexes assemble the KMN network, which harbors the sites of microtubule binding and spindle assembly checkpoint signaling. The buildup of the KMN network that transmits microtubule pulling forces to budding yeast point centromeres is poorly understood. Here, we identify 225 inter-protein crosslinks by mass spectrometry on KMN complexes isolated from Saccharomyces cerevisiae that delineate the KMN subunit connectivity for outer kinetochore assembly. C-Terminal motifs of Nsl1 and Mtw1 recruit the SPC105 complex through Kre28, and both motifs aid tethering of the NDC80 complex by the previously reported Dsn1 C terminus. We show that a hub of three C-terminal MTW1 subunit motifs mediates the cooperative stabilization of the KMN network, which is augmented by a direct NDC80-SPC105 association.
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Affiliation(s)
- Medini Ghodgaonkar-Steger
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Mia Potocnjak
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Tomasz Zimniak
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Josef Fischböck-Halwachs
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Victor Solis-Mezarino
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Sylvia Singh
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Tea Speljko
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Götz Hagemann
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - David Jan Drexler
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Gregor Witte
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
| | - Franz Herzog
- Gene Center Munich and Department of Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany.
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28
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Abstract
Eukaryotic chromosome segregation relies upon specific connections from DNA to the microtubule-based spindle that forms at cell division. The chromosomal locus that directs this process is the centromere, where a structure called the kinetochore forms upon entry into mitosis. Recent crystallography and single-particle electron microscopy have provided unprecedented high-resolution views of the molecular complexes involved in this process. The centromere is epigenetically specified by nucleosomes harbouring a histone H3 variant, CENP-A, and we review recent progress on how it differentiates centromeric chromatin from the rest of the chromosome, the biochemical pathway that mediates its assembly and how two non-histone components of the centromere specifically recognize CENP-A nucleosomes. The core centromeric nucleosome complex (CCNC) is required to recruit a 16-subunit complex termed the constitutive centromere associated network (CCAN), and we highlight recent structures reported of the budding yeast CCAN. Finally, the structures of multiple modular sub-complexes of the kinetochore have been solved at near-atomic resolution, providing insight into how connections are made to the CCAN on one end and to the spindle microtubules on the other. One can now build molecular models from the DNA through to the physical connections to microtubules.
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Affiliation(s)
- Kathryn Kixmoeller
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Praveen Kumar Allu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ben E Black
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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29
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Roscioli E, Germanova TE, Smith CA, Embacher PA, Erent M, Thompson AI, Burroughs NJ, McAinsh AD. Ensemble-Level Organization of Human Kinetochores and Evidence for Distinct Tension and Attachment Sensors. Cell Rep 2020; 31:107535. [PMID: 32348762 PMCID: PMC7196887 DOI: 10.1016/j.celrep.2020.107535] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 02/10/2020] [Accepted: 03/27/2020] [Indexed: 12/13/2022] Open
Abstract
Kinetochores are multi-protein machines that form dynamic attachments to microtubules and control chromosome segregation. High fidelity is ensured because kinetochores can monitor attachment status and tension, using this information to activate checkpoints and error-correction mechanisms. To explore how kinetochores achieve this, we used two- and three-color subpixel fluorescence localization to define how proteins from six major complexes (CCAN, MIS12, NDC80, KNL1, RZZ, and SKA) and the checkpoint proteins Bub1, Mad1, and Mad2 are organized in the human kinetochore. This reveals how the outer kinetochore has a high nematic order and is largely invariant to the loss of attachment or tension, except for two mechanical sensors. First, Knl1 unravels to relay tension, and second, NDC80 undergoes jackknifing and loss of nematic order under microtubule detachment, with only the latter wired up to the checkpoint signaling system. This provides insight into how kinetochores integrate mechanical signals to promote error-free chromosome segregation.
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Affiliation(s)
- Emanuele Roscioli
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK; Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Tsvetelina E Germanova
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK; Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Christopher A Smith
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK; Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Peter A Embacher
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK; Mathematics Institute, University of Warwick, Coventry, UK
| | - Muriel Erent
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK; Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Amelia I Thompson
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK; Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Nigel J Burroughs
- Centre for Mechanochemical Cell Biology, University of Warwick, Coventry, UK; Mathematics Institute, University of Warwick, Coventry, UK.
| | - 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.
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30
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Alex A, Piano V, Polley S, Stuiver M, Voss S, Ciossani G, Overlack K, Voss B, Wohlgemuth S, Petrovic A, Wu Y, Selenko P, Musacchio A, Maffini S. Electroporated recombinant proteins as tools for in vivo functional complementation, imaging and chemical biology. eLife 2019; 8:48287. [PMID: 31310234 PMCID: PMC6656429 DOI: 10.7554/elife.48287] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/12/2019] [Indexed: 02/06/2023] Open
Abstract
Delivery of native or chemically modified recombinant proteins into mammalian cells shows promise for functional investigations and various technological applications, but concerns that sub-cellular localization and functional integrity of delivered proteins may be affected remain high. Here, we surveyed batch electroporation as a delivery tool for single polypeptides and multi-subunit protein assemblies of the kinetochore, a spatially confined and well-studied subcellular structure. After electroporation into human cells, recombinant fluorescent Ndc80 and Mis12 multi-subunit complexes exhibited native localization, physically interacted with endogenous binding partners, and functionally complemented depleted endogenous counterparts to promote mitotic checkpoint signaling and chromosome segregation. Farnesylation is required for kinetochore localization of the Dynein adaptor Spindly. In cells with chronically inhibited farnesyl transferase activity, in vitro farnesylation and electroporation of recombinant Spindly faithfully resulted in robust kinetochore localization. Our data show that electroporation is well-suited to deliver synthetic and chemically modified versions of functional proteins, and, therefore, constitutes a promising tool for applications in chemical and synthetic biology.
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Affiliation(s)
- Amal Alex
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Valentina Piano
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Soumitra Polley
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Marchel Stuiver
- In-Cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Berlin, Germany
| | - Stephanie Voss
- Chemical Genomics Centre, Max Planck Society, Dortmund, Germany
| | - Giuseppe Ciossani
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Katharina Overlack
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Beate Voss
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Sabine Wohlgemuth
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Arsen Petrovic
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Yaowen Wu
- Chemical Genomics Centre, Max Planck Society, Dortmund, Germany.,Department of Chemistry, Umeå University, Umeå, Sweden
| | - Philipp Selenko
- In-Cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Berlin, Germany.,Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany.,Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
| | - Stefano Maffini
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
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31
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Abstract
Mistakes in the process of cell division can lead to the loss, gain or rearrangement of chromosomes. Significant chromosomal abnormalities are usually lethal to the cells and cause spontaneous miscarriages. However, in some cases, defects in the spindle assembly checkpoint lead to severe diseases, such as cancer and birth and development defects, including Down's syndrome. The timely and accurate control of chromosome segregation in mitosis relies on the spindle assembly checkpoint (SAC), an evolutionary conserved, self-regulated signalling system present in higher organisms. The spindle assembly checkpoint is orchestrated by dynamic interactions between spindle microtubules and the kinetochore , a multiprotein complex that constitutes the site for attachment of chromosomes to microtubule polymers to pull sister chromatids apart during cell division. This chapter discusses the current molecular understanding of the essential, highly dynamic molecular interactions underpinning spindle assembly checkpoint signalling and how the complex choreography of interactions can be coordinated in time and space to finely regulate the process. The potential of targeting this signalling pathway to interfere with the abnormal segregation of chromosomes, which occurs in diverse malignancies and the new opportunities that recent technological developments are opening up for a deeper understanding of the spindle assembly checkpoint are also discussed.
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Affiliation(s)
- Victor M Bolanos-Garcia
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK.
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32
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Abstract
The emergence of eukaryotes from ancient prokaryotic lineages embodied a remarkable increase in cellular complexity. While prokaryotes operate simple systems to connect DNA to the segregation machinery during cell division, eukaryotes use a highly complex protein assembly known as the kinetochore. Although conceptually similar, prokaryotic segregation systems and the eukaryotic kinetochore are not homologous. Here we investigate the origins of the kinetochore before the last eukaryotic common ancestor (LECA) using phylogenetic trees, sensitive profile-versus-profile homology detection, and structural comparisons of its protein components. We show that LECA's kinetochore proteins share deep evolutionary histories with proteins involved in a few prokaryotic systems and a multitude of eukaryotic processes, including ubiquitination, transcription, and flagellar and vesicular transport systems. We find that gene duplications played a major role in shaping the kinetochore; more than half of LECA's kinetochore proteins have other kinetochore proteins as closest homologs. Some of these have no detectable homology to any other eukaryotic protein, suggesting that they arose as kinetochore-specific folds before LECA. We propose that the primordial kinetochore evolved from proteins involved in various (pre)eukaryotic systems as well as evolutionarily novel folds, after which a subset duplicated to give rise to the complex kinetochore of LECA.
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33
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Abstract
Faithful transmission of genetic information during cell division requires attachment of chromosomes to the mitotic spindle via the kinetochore. In vitro reconstitution studies are beginning to uncover how the kinetochore is assembled upon the underlying centromere, how the kinetochore couples chromosome movement to microtubule dynamics, and how cells ensure the site of kinetochore assembly is maintained from one generation to the next. Here we give special emphasis to advances made in Xenopus egg extract, which provides a unique, biochemically tractable in vitro system that affords the complexity of cytoplasm and nucleoplasm to permit reconstitution of the dynamic, cell cycle-regulated functions of the centromere and kinetochore.
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Affiliation(s)
- Bradley T French
- Department of Biochemistry, Stanford University, 279 Campus Drive, Beckman 409, Stanford, CA, 94305, USA
| | - Aaron F Straight
- Department of Biochemistry, Stanford University, 279 Campus Drive, Beckman 409, Stanford, CA, 94305, USA.
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34
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Abstract
Eukaryotic kinetochores connect spindlemicrotubules to chromosomal centromeres. A group of proteins called the Ctf19 complex (Ctf19c) in yeast and the constitutive centromere associated network (CCAN) in other organisms creates the foundation of a kinetochore. The Ctf19c/CCAN influences the timing of kinetochore assembly, sets its location by associating with a specialized nucleosome containing the histone H3 variant Cse4/CENP-A, and determines the organization of the microtubule attachment apparatus. We present here the structure of a reconstituted 13-subunit Ctf19c determined by cryo-electron microscopy at ~4 Å resolution. The structure accounts for known and inferred contacts with the Cse4 nucleosome and for an observed assembly hierarchy. We describe its implications for establishment of kinetochores and for their regulation by kinases throughout the cell cycle.
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Affiliation(s)
- Stephen M Hinshaw
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Howard Hughes Medical Institute, Boston, United States
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Howard Hughes Medical Institute, Boston, United States
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Chen C, Whitney IP, Banerjee A, Sacristan C, Sekhri P, Kern DM, Fontan A, Kops GJPL, Tyson JJ, Cheeseman IM, Joglekar AP. Ectopic Activation of the Spindle Assembly Checkpoint Signaling Cascade Reveals Its Biochemical Design. Curr Biol 2018; 29:104-119.e10. [PMID: 30595520 DOI: 10.1016/j.cub.2018.11.054] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 11/13/2018] [Accepted: 11/21/2018] [Indexed: 11/27/2022]
Abstract
Switch-like activation of the spindle assembly checkpoint (SAC) is critical for accurate chromosome segregation and for cell division in a timely manner. To determine the mechanisms that achieve this, we engineered an ectopic, kinetochore-independent SAC activator: the "eSAC." The eSAC stimulates SAC signaling by artificially dimerizing Mps1 kinase domain and a cytosolic KNL1 phosphodomain, the kinetochore signaling scaffold. By exploiting variable eSAC expression in a cell population, we defined the dependence of the eSAC-induced mitotic delay on eSAC concentration in a cell to reveal the dose-response behavior of the core signaling cascade of the SAC. These quantitative analyses and subsequent mathematical modeling of the dose-response data uncover two crucial properties of the core SAC signaling cascade: (1) a cellular limit on the maximum anaphase-inhibitory signal that the cascade can generate due to the limited supply of SAC proteins and (2) the ability of the KNL1 phosphodomain to produce the anaphase-inhibitory signal synergistically, when it recruits multiple SAC proteins simultaneously. We propose that these properties together achieve inverse, non-linear scaling between the signal output per kinetochore and the number of signaling kinetochores. When the number of kinetochores is low, synergistic signaling by KNL1 enables each kinetochore to produce a disproportionately strong signal output. However, when many kinetochores signal concurrently, they compete for a limited supply of SAC proteins. This frustrates synergistic signaling and lowers their signal output. Thus, the signaling activity of unattached kinetochores will adapt to the changing number of signaling kinetochores to enable the SAC to approximate switch-like behavior.
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Affiliation(s)
- Chu Chen
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ian P Whitney
- Whitehead Institute for Biomedical Research and Department of Biology, MIT, Nine Cambridge Center, Cambridge, MA 02142, USA
| | - Anand Banerjee
- Department of Biological Sciences, Virginia Polytechnic Institute & State University, Blacksburg, VA 24061, USA
| | - Carlos Sacristan
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences), and Molecular Cancer Research, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Palak Sekhri
- Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - David M Kern
- Whitehead Institute for Biomedical Research and Department of Biology, MIT, Nine Cambridge Center, Cambridge, MA 02142, USA
| | - Adrienne Fontan
- Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Geert J P L Kops
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences), and Molecular Cancer Research, University Medical Center Utrecht, Utrecht, the Netherlands
| | - John J Tyson
- Department of Biological Sciences, Virginia Polytechnic Institute & State University, Blacksburg, VA 24061, USA
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research and Department of Biology, MIT, Nine Cambridge Center, Cambridge, MA 02142, USA
| | - Ajit P Joglekar
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109, USA; Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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36
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Affiliation(s)
- Yang Yang
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Hongtao Yu
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Amin P, Soper Ní Chafraidh S, Leontiou I, Hardwick KG. Regulated reconstitution of spindle checkpoint arrest and silencing through chemically induced dimerisation in vivo. J Cell Sci 2018; 132:jcs.219766. [PMID: 30237224 PMCID: PMC6398473 DOI: 10.1242/jcs.219766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/04/2018] [Indexed: 12/19/2022] Open
Abstract
Chemically induced dimerisation (CID) uses small molecules to control specific protein-protein interactions. We employed CID dependent on the plant hormone abscisic acid (ABA) to reconstitute spindle checkpoint signalling in fission yeast. The spindle checkpoint signal usually originates at unattached or inappropriately attached kinetochores. These are complex, multiprotein structures with several important functions. To bypass kinetochore complexity, we took a reductionist approach to studying checkpoint signalling. We generated a synthetic checkpoint arrest ectopically by inducing heterodimerisation of the checkpoint proteins Mph1 (the fission yeast homologue of Mps1) and Spc7 (the fission yeast homologue of KNL1). These proteins were engineered such that they cannot localise to kinetochores, and only form a complex in the presence of ABA. Using this novel assay we were able to checkpoint arrest a synchronous population of cells within 30 min of ABA addition. This assay allows detailed genetic dissection of checkpoint activation and, importantly, also provides a valuable tool for studying checkpoint silencing. To analyse silencing of the checkpoint and the ensuing mitotic exit, we simply washed out the ABA from arrested fission yeast cells. We show here that silencing is critically dependent on protein phosphatase 1 (PP1) recruitment to Mph1-Spc7 signalling platforms.
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Affiliation(s)
- Priya Amin
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Sadhbh Soper Ní Chafraidh
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Ioanna Leontiou
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Kevin G Hardwick
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Max Born Crescent, Edinburgh, EH9 3BF, UK
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Pesenti ME, Prumbaum D, Auckland P, Smith CM, Faesen AC, Petrovic A, Erent M, Maffini S, Pentakota S, Weir JR, Lin YC, Raunser S, McAinsh AD, Musacchio A. Reconstitution of a 26-Subunit Human Kinetochore Reveals Cooperative Microtubule Binding by CENP-OPQUR and NDC80. Mol Cell 2018; 71:923-939.e10. [PMID: 30174292 DOI: 10.1016/j.molcel.2018.07.038] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/04/2018] [Accepted: 07/25/2018] [Indexed: 12/15/2022]
Abstract
The approximately thirty core subunits of kinetochores assemble on centromeric chromatin containing the histone H3 variant CENP-A and connect chromosomes with spindle microtubules. The chromatin proximal 16-subunit CCAN (constitutive centromere associated network) creates a mechanically stable bridge between CENP-A and the kinetochore’s microtubule-binding machinery, the 10-subunit KMN assembly. Here, we reconstituted a stoichiometric 11-subunit human CCAN core that forms when the CENP-OPQUR complex binds to a joint interface on the CENP-HIKM and CENP-LN complexes. The resulting CCAN particle is globular and connects KMN and CENP-A in a 26-subunit recombinant particle. The disordered, basic N-terminal tail of CENP-Q binds microtubules and promotes accurate chromosome alignment, cooperating with KMN in microtubule binding. The N-terminal basic tail of the NDC80 complex, the microtubule-binding subunit of KMN, can functionally replace the CENP-Q tail. Our work dissects the connectivity and architecture of CCAN and reveals unexpected functional similarities between CENP-OPQUR and the NDC80 complex. The kinetochore CENP-OPQUR complex is reconstituted and functionally dissected A kinetochore particle with 26 subunits and defined stoichiometry is reconstituted EM structure of an 11-subunit inner kinetochore complex reveals globular shape CENP-Q and the Ndc80 complex bind microtubules cooperatively
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Pan D, Brockmeyer A, Mueller F, Musacchio A, Bange T. Simplified Protocol for Cross-linking Mass Spectrometry Using the MS-Cleavable Cross-linker DSBU with Efficient Cross-link Identification. Anal Chem 2018; 90:10990-10999. [PMID: 30074391 DOI: 10.1021/acs.analchem.8b02593] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chemical cross-linking combined with mass spectrometry (MS) is a powerful approach to identify and map protein-protein interactions. Its applications support computational modeling of three-dimensional structures and complement classical structural methodologies such as X-ray crystallography, NMR spectroscopy, and electron microscopy (EM). A plethora of cross-linkers, MS methods, and data analysis programs have been developed, but due to their methodological complexity application is currently reserved for specialized mass spectrometry laboratories. Here, we present a simplified single-step purification protocol that results in improved identifications of cross-linked peptides. We describe an easy-to-follow pipeline that combines the MS-cleavable cross-linker DSBU (disuccinimidyl dibutyric urea), a Q-Exactive mass spectrometer, and the dedicated software MeroX for data analysis to make cross-linking MS accessible to structural biology and biochemistry laboratories. In experiments focusing on kinetochore subcomplexes containing 4-10 subunits (so-called KMN network), one-step peptide purification, and enrichment by size-exclusion chromatography yielded identification of 135-228 non-redundant cross-links (577-820 cross-linked peptides) from each experiment. Notably, half of the non-redundant cross-links identified were not lysine-lysine cross-links and involved side chains with hydroxy groups. The new pipeline has a comparable potential toward the identification of protein-protein interactions as previously used pipelines based on isotope-labeled cross-linkers. A newly identified cross-link enabled us to improve our 3D-model of the KMN, emphasizing the power of cross-linking data for evaluation of low-resolution EM maps. In sum, our optimized experimental scheme represents a viable shortcut toward obtaining reliable cross-link data sets.
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Affiliation(s)
- Dongqing Pan
- Department of Mechanistic Cell Biology , Max Planck Institute of Molecular Physiology , Otto-Hahn-Str. 11 , 44227 Dortmund , Germany
| | - Andreas Brockmeyer
- Department of Chemical Biology , Max Planck Institute of Molecular Physiology , Otto-Hahn-Str. 11 , 44227 Dortmund , Germany
| | - Franziska Mueller
- Department of Mechanistic Cell Biology , Max Planck Institute of Molecular Physiology , Otto-Hahn-Str. 11 , 44227 Dortmund , Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology , Max Planck Institute of Molecular Physiology , Otto-Hahn-Str. 11 , 44227 Dortmund , Germany.,Centre for Medical Biotechnology, Faculty of Biology , University Duisburg-Essen , Universitaetsstrasse , 45141 Essen , Germany
| | - Tanja Bange
- Department of Mechanistic Cell Biology , Max Planck Institute of Molecular Physiology , Otto-Hahn-Str. 11 , 44227 Dortmund , Germany.,Department for Systems Chronobiology , Institute of Medical Psychology, LMU Munich , Goethe-Str. 31 , 80336 Munich , Germany
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Naveed M, Kazmi SK, Amin M, Asif Z, Islam U, Shahid K, Tehreem S. Comprehensive review on the molecular genetics of autosomal recessive primary microcephaly (MCPH). Genet Res (Camb) 2018; 100:e7. [PMID: 30086807 DOI: 10.1017/S0016672318000046] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Primary microcephaly (MCPH) is an autosomal recessive sporadic neurodevelopmental ailment with a trivial head size characteristic that is below 3-4 standard deviations. MCPH is the smaller upshot of an architecturally normal brain; a significant decrease in size is seen in the cerebral cortex. At birth MCPH presents with non-progressive mental retardation, while secondary microcephaly (onset after birth) presents with and without other syndromic features. MCPH is a neurogenic mitotic syndrome nevertheless pretentious patients demonstrate normal neuronal migration, neuronal apoptosis and neural function. Eighteen MCPH loci (MCPH1-MCPH18) have been mapped to date from various populations around the world and contain the following genes: Microcephalin, WDR62, CDK5RAP2, CASC5, ASPM, CENPJ, STIL, CEP135, CEP152, ZNF335, PHC1, CDK6, CENPE, SASS6, MFSD2A, ANKLE2, CIT and WDFY3, clarifying our understanding about the molecular basis of microcephaly genetic disorder. It has previously been reported that phenotype disease is caused by MCB gene mutations and the causes of this phenotype are disarrangement of positions and organization of chromosomes during the cell cycle as a result of mutated DNA, centriole duplication, neurogenesis, neuronal migration, microtubule dynamics, transcriptional control and the cell cycle checkpoint having some invisible centrosomal process that can manage the number of neurons that are produced by neuronal precursor cells. Furthermore, researchers inform us about the clinical management of families that are suffering from MCPH. Establishment of both molecular understanding and genetic advocating may help to decrease the rate of this ailment. This current review study examines newly identified genes along with previously identified genes involved in autosomal recessive MCPH.
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Hoischen C, Yavas S, Wohland T, Diekmann S. CENP-C/H/I/K/M/T/W/N/L and hMis12 but not CENP-S/X participate in complex formation in the nucleoplasm of living human interphase cells outside centromeres. PLoS One 2018; 13:e0192572. [PMID: 29509805 PMCID: PMC5839545 DOI: 10.1371/journal.pone.0192572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 01/25/2018] [Indexed: 12/25/2022] Open
Abstract
Kinetochore proteins assemble onto centromeric chromatin and regulate DNA segregation during cell division. The inner kinetochore proteins bind centromeres while most outer kinetochore proteins assemble at centromeres during mitosis, connecting the complex to microtubules. Here, we measured the co-migration between protein pairs of the constitutive centromere associated network (CCAN) and hMis12 complexes by fluorescence cross-correlation spectroscopy (FCCS) in the nucleoplasm outside centromeres in living human interphase cells. FCCS is a method that can tell if in living cells two differently fluorescently labelled molecules migrate independently, or co-migrate and thus are part of one and the same soluble complex. We also determined the apparent dissociation constants (Kd) of the hetero-dimers CENP-T/W and CENP-S/X. We measured co-migration between CENP-K and CENP-T as well as between CENP-M and CENP-T but not between CENP-T/W and CENP-S/X. Furthermore, CENP-C co-migrated with CENP-H, and CENP-K with CENP-N as well as with CENP-L. Thus, in the nucleoplasm outside centromeres, a large fraction of the CENP-H/I/K/M proteins interact with CENP-C, CENP-N/L and CENP-T/W but not with CENP-S/X. Our FCCS analysis of the Mis12 complex showed that hMis12, Nsl1, Dsn1 and Nnf1 also form a complex outside centromeres of which at least hMis12 associated with the CENP-C/H/I/K/M/T/W/N/L complex.
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Affiliation(s)
- Christian Hoischen
- Molecular Biology, Leibniz Institute on Aging-Friz-Lipmann-Institute (FLI), Jena, Germany
| | - Sibel Yavas
- Departments of Biological Sciences and Chemistry and Centre of Bioimaging Sciences, Lee Wee Kheng Buildung, National University of Singapore, Singapore, Singapore
| | - Thorsten Wohland
- Departments of Biological Sciences and Chemistry and Centre of Bioimaging Sciences, Lee Wee Kheng Buildung, National University of Singapore, Singapore, Singapore
| | - Stephan Diekmann
- Molecular Biology, Leibniz Institute on Aging-Friz-Lipmann-Institute (FLI), Jena, Germany
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42
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Shin J, Jeong G, Park JY, Kim H, Lee I. MUN (MERISTEM UNSTRUCTURED), encoding a SPC24 homolog of NDC80 kinetochore complex, affects development through cell division in Arabidopsis thaliana. Plant J 2018; 93:977-991. [PMID: 29356153 DOI: 10.1111/tpj.13823] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 11/24/2017] [Accepted: 12/14/2017] [Indexed: 05/22/2023]
Abstract
Kinetochore, a protein super-complex on the centromere of chromosomes, mediates chromosome segregation during cell division by providing attachment sites for spindle microtubules. The NDC80 complex, composed of four proteins, NDC80, NUF2, SPC24 and SPC25, is localized at the outer kinetochore and connects spindle fibers to the kinetochore. Although it is conserved across species, functional studies of this complex are rare in Arabidopsis. Here, we characterize a recessive mutant, meristem unstructured-1 (mun-1), exhibiting an abnormal phenotype with unstructured shoot apical meristem caused by ectopic expression of the WUSCHEL gene in unexpected tissues. mun-1 is a weak allele because of the insertion of T-DNA in the promoter region of the SPC24 homolog. The mutant exhibits stunted growth, embryo arrest, DNA aneuploidy, and defects in chromosome segregation with a low cell division rate. Null mutants of MUN from TALEN and CRISPR/Cas9-mediated mutagenesis showed zygotic embryonic lethality similar to nuf2-1; however, the null mutations were fully transmissible via pollen and ovules. Interactions among the components of the NDC80 complex were confirmed in a yeast two-hybrid assay and in planta co-immunoprecipitation. MUN is co-localized at the centromere with HTR12/CENH3, which is a centromere-specific histone variant, but MUN is not required to recruit HTR12/CENH3 to the kinetochore. Our results support that MUN is a functional homolog of SPC24 in Arabidopsis, which is required for proper cell division. In addition, we report the ectopic generations of stem cell niches by the malfunction of kinetochore components.
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Affiliation(s)
- Jinwoo Shin
- Laboratory of Plant Developmental Genetics, School of Biological Sciences, Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
| | - Goowon Jeong
- Laboratory of Plant Developmental Genetics, School of Biological Sciences, Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
| | - Jong-Yoon Park
- Laboratory of Plant Developmental Genetics, School of Biological Sciences, Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
| | - Hoyeun Kim
- Laboratory of Plant Developmental Genetics, School of Biological Sciences, Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
| | - Ilha Lee
- Laboratory of Plant Developmental Genetics, School of Biological Sciences, Plant Genomics and Breeding Institute, Seoul National University, Seoul, 08826, Korea
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43
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Zhou X, Zheng F, Wang C, Wu M, Zhang X, Wang Q, Yao X, Fu C, Zhang X, Zang J. Phosphorylation of CENP-C by Aurora B facilitates kinetochore attachment error correction in mitosis. Proc Natl Acad Sci U S A 2017; 114:E10667-76. [PMID: 29180432 DOI: 10.1073/pnas.1710506114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Kinetochores are large protein networks located on centromeres that mediate chromosome segregation during mitosis and maintain genomic stability. Mis12 complex (Mis12C) functions as a scaffold that targets Ndc80 and Knl1 complexes to the centromere by associating with CENP-C. Here, we provide insights into the molecular mechanism underlying the CENP-C–dependent kinetochore recruitment of Mis12C, which is negatively regulated by Aurora B-dependent CENP-C phosphorylation. Replacement of Schizosaccharomyces pombe Cnp3 with a phosphorylation-mimicking mutant, Cnp3T28E, results in defective chromosome segregation caused by improper kinetochore assembly. These findings indicate that Aurora B-dependent phosphorylation of CENP-C plays a role in interrupting the connection between the inner and outer kinetochore and is thus involved in the error correction/spindle assembly checkpoint pathway to prevent chromosome missegregation during mitosis. Kinetochores are superprotein complexes that orchestrate chromosome segregation via a dynamic interaction with spindle microtubules. A physical connection between CENP-C and the Mis12–Ndc80–Knl1 (KMN) protein network is an important pathway that is used to assemble kinetochores on CENP-A nucleosomes. Multiple outer kinetochore components are phosphorylated by Aurora B kinase to activate the spindle assembly checkpoint (SAC) and to ensure accurate chromosome segregation. However, it is unknown whether Aurora B can phosphorylate inner kinetochore components to facilitate proper mitotic chromosome segregation. Here, we reported the structure of the fission yeast Schizosaccharomyces pombe Mis12–Nnf1 complex and showed that N-terminal residues 26–50 in Cnp3 (the CENP-C homolog of S. pombe) are responsible for interacting with the Mis12 complex. Interestingly, Thr28 of Cnp3 is a substrate of Ark1 (the Aurora B homolog of S. pombe), and phosphorylation impairs the interaction between the Cnp3 and Mis12 complex. The expression of a phosphorylation-mimicking Cnp3 mutant results in defective chromosome segregation due to improper kinetochore assembly. These results establish a previously uncharacterized regulatory mechanism involved in CENP-C–Mis12-facilitated kinetochore attachment error correction to ensure accurate chromosome segregation during mitosis.
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44
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Valverde R, Ingram J, Harrison SC. Conserved Tetramer Junction in the Kinetochore Ndc80 Complex. Cell Rep 2017; 17:1915-1922. [PMID: 27851957 PMCID: PMC5131873 DOI: 10.1016/j.celrep.2016.10.065] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/07/2016] [Accepted: 10/18/2016] [Indexed: 12/14/2022] Open
Abstract
The heterotetrameric Ndc80 complex establishes connectivity along the principal longitudinal axis of a kinetochore. Its two heterodimeric subcomplexes, each with a globular end and a coiled-coil shaft, connect end-to-end to create a ∼600 Å long rod spanning the gap from centromere-proximal structures to spindle microtubules. Neither subcomplex has a known function on its own, but the heterotetrameric organization and the characteristics of the junction are conserved from yeast to man. We have determined crystal structures of two shortened ("dwarf") Ndc80 complexes that contain the full tetramer junction and both globular ends. The junction connects two α-helical coiled coils through regions of four-chain and three-chain overlap. The complexity of its structure depends on interactions among conserved amino-acid residues, suggesting a binding site for additional cellular factor(s) not yet identified.
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Affiliation(s)
- Roberto Valverde
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, and Howard Hughes Medical Institute, 250 Longwood Avenue, Boston, MA 02115, USA
| | - Jessica Ingram
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Stephen C Harrison
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, and Howard Hughes Medical Institute, 250 Longwood Avenue, Boston, MA 02115, USA.
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Schmitzberger F, Richter MM, Gordiyenko Y, Robinson CV, Dadlez M, Westermann S. Molecular basis for inner kinetochore configuration through RWD domain-peptide interactions. EMBO J 2017; 36:3458-3482. [PMID: 29046335 PMCID: PMC5709738 DOI: 10.15252/embj.201796636] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 07/31/2017] [Accepted: 09/08/2017] [Indexed: 01/05/2023] Open
Abstract
Kinetochores are dynamic cellular structures that connect chromosomes to microtubules. They form from multi‐protein assemblies that are evolutionarily conserved between yeasts and humans. One of these assemblies—COMA—consists of subunits Ame1CENP‐U, Ctf19CENP‐P, Mcm21CENP‐O and Okp1CENP‐Q. A description of COMA molecular organization has so far been missing. We defined the subunit topology of COMA, bound with inner kinetochore proteins Nkp1 and Nkp2, from the yeast Kluyveromyces lactis, with nanoflow electrospray ionization mass spectrometry, and mapped intermolecular contacts with hydrogen‐deuterium exchange coupled to mass spectrometry. Our data suggest that the essential Okp1 subunit is a multi‐segmented nexus with distinct binding sites for Ame1, Nkp1‐Nkp2 and Ctf19‐Mcm21. Our crystal structure of the Ctf19‐Mcm21 RWD domains bound with Okp1 shows the molecular contacts of this important inner kinetochore joint. The Ctf19‐Mcm21 binding motif in Okp1 configures a branch of mitotic inner kinetochores, by tethering Ctf19‐Mcm21 and Chl4CENP‐N‐Iml3CENP‐L. Absence of this motif results in dependence on the mitotic checkpoint for viability.
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Affiliation(s)
- Florian Schmitzberger
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA .,Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Magdalena M Richter
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Yuliya Gordiyenko
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Carol V Robinson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Michał Dadlez
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.,Institute of Genetics and Biotechnology, Biology Department, Warsaw University, Warsaw, Poland
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Abstract
The genetic material, contained on chromosomes, is often described as the "blueprint for life." During nuclear division, the chromosomes are pulled into each of the two daughter nuclei by the coordination of spindle microtubules, kinetochores, centromeres, and chromatin. These four functional units must link the chromosomes to the microtubules, signal to the cell when the attachment is made so that division can proceed, and withstand the force generated by pulling the chromosomes to either daughter cell. To perform each of these functions, kinetochores are large protein complexes, approximately 5MDa in size, and they contain at least 45 unique proteins. Many of the central components in the kinetochore are well conserved, yielding a common core of proteins forming consistent structures. However, many of the peripheral subcomplexes vary between different taxonomic groups, including changes in primary sequence and gain or loss of whole proteins. It is still unclear how significant these changes are, and answers to this question may provide insights into adaptation to specific lifestyles or progression of disease that involve chromosome instability.
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Akiyoshi B. The unconventional kinetoplastid kinetochore: from discovery toward functional understanding. Biochem Soc Trans 2016; 44:1201-17. [PMID: 27911702 DOI: 10.1042/BST20160112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/15/2016] [Accepted: 06/21/2016] [Indexed: 11/17/2022]
Abstract
The kinetochore is the macromolecular protein complex that drives chromosome segregation in eukaryotes. Its most fundamental function is to connect centromeric DNA to dynamic spindle microtubules. Studies in popular model eukaryotes have shown that centromere protein (CENP)-A is critical for DNA-binding, whereas the Ndc80 complex is essential for microtubule-binding. Given their conservation in diverse eukaryotes, it was widely believed that all eukaryotes would utilize these components to make up a core of the kinetochore. However, a recent study identified an unconventional type of kinetochore in evolutionarily distant kinetoplastid species, showing that chromosome segregation can be achieved using a distinct set of proteins. Here, I review the discovery of the two kinetochore systems and discuss how their studies contribute to a better understanding of the eukaryotic chromosome segregation machinery.
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Abstract
During eukaryotic cell division, the sister chromatids of duplicated chromosomes are pulled apart by microtubules, which connect via kinetochores. The kinetochore is a multiprotein structure that links centromeres to microtubules, and that emits molecular signals in order to safeguard the equal distribution of duplicated chromosomes over daughter cells. Although microtubule‐mediated chromosome segregation is evolutionary conserved, kinetochore compositions seem to have diverged. To systematically inventory kinetochore diversity and to reconstruct its evolution, we determined orthologs of 70 kinetochore proteins in 90 phylogenetically diverse eukaryotes. The resulting ortholog sets imply that the last eukaryotic common ancestor (LECA) possessed a complex kinetochore and highlight that current‐day kinetochores differ substantially. These kinetochores diverged through gene loss, duplication, and, less frequently, invention and displacement. Various kinetochore components co‐evolved with one another, albeit in different manners. These co‐evolutionary patterns improve our understanding of kinetochore function and evolution, which we illustrated with the RZZ complex, TRIP13, the MCC, and some nuclear pore proteins. The extensive diversity of kinetochore compositions in eukaryotes poses numerous questions regarding evolutionary flexibility of essential cellular functions.
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Affiliation(s)
- Jolien Je van Hooff
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences), Utrecht, The Netherlands.,Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands.,Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Eelco Tromer
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences), Utrecht, The Netherlands.,Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands
| | - Leny M van Wijk
- Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands
| | - Berend Snel
- Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands
| | - Geert Jpl Kops
- Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences), Utrecht, The Netherlands .,Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands.,Cancer Genomics Netherlands, University Medical Center Utrecht, Utrecht, The Netherlands
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Hammond RG, Tan X, Johnson MA. SARS-unique fold in the Rousettus bat coronavirus HKU9. Protein Sci 2017; 26:1726-1737. [PMID: 28580734 PMCID: PMC5563143 DOI: 10.1002/pro.3208] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/26/2017] [Accepted: 05/26/2017] [Indexed: 12/28/2022]
Abstract
The coronavirus nonstructural protein 3 (nsp3) is a multifunctional protein that comprises multiple structural domains. This protein assists viral polyprotein cleavage, host immune interference, and may play other roles in genome replication or transcription. Here, we report the solution NMR structure of a protein from the “SARS‐unique region” of the bat coronavirus HKU9. The protein contains a frataxin fold or double‐wing motif, which is an α + β fold that is associated with protein/protein interactions, DNA binding, and metal ion binding. High structural similarity to the human severe acute respiratory syndrome (SARS) coronavirus nsp3 is present. A possible functional site that is conserved among some betacoronaviruses has been identified using bioinformatics and biochemical analyses. This structure provides strong experimental support for the recent proposal advanced by us and others that the “SARS‐unique” region is not unique to the human SARS virus, but is conserved among several different phylogenetic groups of coronaviruses and provides essential functions. PDB Code(s): 5UTV
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Affiliation(s)
- Robert G Hammond
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Xuan Tan
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama, 35294
| | - Margaret A Johnson
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama, 35294
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McKinley KL, Cheeseman IM. Large-Scale Analysis of CRISPR/Cas9 Cell-Cycle Knockouts Reveals the Diversity of p53-Dependent Responses to Cell-Cycle Defects. Dev Cell 2017; 40:405-420.e2. [PMID: 28216383 DOI: 10.1016/j.devcel.2017.01.012] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/23/2016] [Accepted: 01/23/2017] [Indexed: 12/20/2022]
Abstract
Defining the genes that are essential for cellular proliferation is critical for understanding organismal development and identifying high-value targets for disease therapies. However, the requirements for cell-cycle progression in human cells remain incompletely understood. To elucidate the consequences of acute and chronic elimination of cell-cycle proteins, we generated and characterized inducible CRISPR/Cas9 knockout human cell lines targeting 209 genes involved in diverse cell-cycle processes. We performed single-cell microscopic analyses to systematically establish the effects of the knockouts on subcellular architecture. To define variations in cell-cycle requirements between cultured cell lines, we generated knockouts across cell lines of diverse origins. We demonstrate that p53 modulates the phenotype of specific cell-cycle defects through distinct mechanisms, depending on the defect. This work provides a resource to broadly facilitate robust and long-term depletion of cell-cycle proteins and reveals insights into the requirements for cell-cycle progression.
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Affiliation(s)
- Kara L McKinley
- Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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