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Mayer C, Vogt A, Uslu T, Scalzitti N, Chennen K, Poch O, Thompson JD. CeGAL: Redefining a Widespread Fungal-Specific Transcription Factor Family Using an In Silico Error-Tracking Approach. J Fungi (Basel) 2023; 9:jof9040424. [PMID: 37108879 PMCID: PMC10141177 DOI: 10.3390/jof9040424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/21/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023] Open
Abstract
In fungi, the most abundant transcription factor (TF) class contains a fungal-specific ‘GAL4-like’ Zn2C6 DNA binding domain (DBD), while the second class contains another fungal-specific domain, known as ‘fungal_trans’ or middle homology domain (MHD), whose function remains largely uncharacterized. Remarkably, almost a third of MHD-containing TFs in public sequence databases apparently lack DNA binding activity, since they are not predicted to contain a DBD. Here, we reassess the domain organization of these ‘MHD-only’ proteins using an in silico error-tracking approach. In a large-scale analysis of ~17,000 MHD-only TF sequences present in all fungal phyla except Microsporidia and Cryptomycota, we show that the vast majority (>90%) result from genome annotation errors and we are able to predict a new DBD sequence for 14,261 of them. Most of these sequences correspond to a Zn2C6 domain (82%), with a small proportion of C2H2 domains (4%) found only in Dikarya. Our results contradict previous findings that the MHD-only TF are widespread in fungi. In contrast, we show that they are exceptional cases, and that the fungal-specific Zn2C6–MHD domain pair represents the canonical domain signature defining the most predominant fungal TF family. We call this family CeGAL, after the highly characterized members: Cep3, whose 3D structure is determined, and GAL4, a eukaryotic TF archetype. We believe that this will not only improve the annotation and classification of the Zn2C6 TF but will also provide critical guidance for future fungal gene regulatory network analyses.
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Affiliation(s)
- Claudine Mayer
- Complex Systems and Translational Bioinformatics (CSTB), ICube Laboratory, UMR7357, University of Strasbourg, 1 rue Eugène Boeckel, 67000 Strasbourg, France
- Faculté des Sciences, Université Paris Cité, UFR Sciences du Vivant, 75013 Paris, France
- Correspondence: (C.M.); (J.D.T.)
| | - Arthur Vogt
- Complex Systems and Translational Bioinformatics (CSTB), ICube Laboratory, UMR7357, University of Strasbourg, 1 rue Eugène Boeckel, 67000 Strasbourg, France
| | - Tuba Uslu
- Complex Systems and Translational Bioinformatics (CSTB), ICube Laboratory, UMR7357, University of Strasbourg, 1 rue Eugène Boeckel, 67000 Strasbourg, France
| | - Nicolas Scalzitti
- Complex Systems and Translational Bioinformatics (CSTB), ICube Laboratory, UMR7357, University of Strasbourg, 1 rue Eugène Boeckel, 67000 Strasbourg, France
| | - Kirsley Chennen
- Complex Systems and Translational Bioinformatics (CSTB), ICube Laboratory, UMR7357, University of Strasbourg, 1 rue Eugène Boeckel, 67000 Strasbourg, France
| | - Olivier Poch
- Complex Systems and Translational Bioinformatics (CSTB), ICube Laboratory, UMR7357, University of Strasbourg, 1 rue Eugène Boeckel, 67000 Strasbourg, France
| | - Julie D. Thompson
- Complex Systems and Translational Bioinformatics (CSTB), ICube Laboratory, UMR7357, University of Strasbourg, 1 rue Eugène Boeckel, 67000 Strasbourg, France
- Correspondence: (C.M.); (J.D.T.)
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Casado-del Castillo V, Benito EP, Díaz-Mínguez JM. The Role of the Fusarium oxysporum FTF2 Transcription Factor in Host Colonization and Virulence in Common Bean Plants (Phaseolus vulgaris L.). Pathogens 2023; 12:pathogens12030380. [PMID: 36986302 PMCID: PMC10054582 DOI: 10.3390/pathogens12030380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/17/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023] Open
Abstract
The FTF (Fusarium Transcription Factor) gene family is composed of two members (FTF1 and FTF2) with high-sequence homology that encode transcription factors involved in the modulation of virulence in the F. oxysporum species complex (FOSC). While FTF1 is a multicopy gene exclusive of highly virulent strains of FOSC and is located in the accessory genome, FTF2 is a single-copy gene, located in the core genome, and well-conserved in all filamentous ascomycete fungi, except yeast. The involvement of FTF1 in the colonization of the vascular system and regulation of the expression of SIX effectors has been stablished. To address the role of FTF2, we generated and characterized mutants defective in FTF2 in a F. oxysporum f. sp. phaseoli weakly virulent strain and analyzed them together with the equivalent mutants formerly obtained in a highly virulent strain. The results obtained highlight a role for FTF2 as a negative regulator of the production of macroconidia and demonstrate that it is required for full virulence and the positive regulation of SIX effectors. In addition, gene expression analyses provided compelling evidence that FTF2 is involved in the regulation of hydrophobins likely required for plant colonization.
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Yan K, Zhang Z, Yang J, McLaughlin SH, Barford D. Architecture of the CBF3-centromere complex of the budding yeast kinetochore. Nat Struct Mol Biol 2018; 25:1103-1110. [PMID: 30478265 PMCID: PMC6292502 DOI: 10.1038/s41594-018-0154-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/10/2018] [Indexed: 01/01/2023]
Abstract
Kinetochores are multicomponent complexes responsible for coordinating the attachment of centromeric DNA to mitotic-spindle microtubules. The point centromeres of budding yeast are organized into three centromeric determining elements (CDEs), and are associated with the centromere-specific nucleosome Cse4. Deposition of Cse4 at CEN loci is dependent on the CBF3 complex that engages CDEIII to direct Cse4 nucleosomes to CDEII. To understand how CBF3 recognizes CDEIII and positions Cse4, we determined a cryo-EM structure of a CBF3-CEN complex. CBF3 interacts with CEN DNA as a head-to-head dimer that includes the whole of CDEIII and immediate 3' regions. Specific CEN-binding of CBF3 is mediated by a Cep3 subunit of one of the CBF3 protomers that forms major groove interactions with the conserved and essential CCG and TGT motifs of CDEIII. We propose a model for a CBF3-Cse4-CEN complex with implications for understanding CBF3-directed deposition of the Cse4 nucleosome at CEN loci.
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Affiliation(s)
- Kaige Yan
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Cambridge, UK
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Zhang W, Lukoyanova N, Miah S, Lucas J, Vaughan CK. Insights into Centromere DNA Bending Revealed by the Cryo-EM Structure of the Core Centromere Binding Factor 3 with Ndc10. Cell Rep 2018; 24:744-754. [PMID: 30021170 PMCID: PMC6077249 DOI: 10.1016/j.celrep.2018.06.068] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/06/2018] [Accepted: 06/15/2018] [Indexed: 12/21/2022] Open
Abstract
The centromere binding factor 3 (CBF3) complex binds the third centromere DNA element in organisms with point centromeres, such as S. cerevisiae. It is an essential complex for assembly of the kinetochore in these organisms, as it facilitates genetic centromere specification and allows association of all other kinetochore components. We determined high-resolution structures of the core complex of CBF3 alone and in association with a monomeric construct of Ndc10, using cryoelectron microscopy (cryo-EM). We identify the DNA-binding site of the complex and present a model in which CBF3 induces a tight bend in centromeric DNA, thus facilitating assembly of the centromeric nucleosome. Cryo-EM studies of CBF3 reveal the core complex has a deep asymmetric channel The size, conservation, and charge of the channel suggest that it binds centromere DNA Unique insertions in the Ctf13 F box provide the binding site for one Ndc10 monomer The Ndc10 DNA-binding site is in plane with and perpendicular to the CBF3 channel
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Affiliation(s)
- Wenjuan Zhang
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK; Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Natalya Lukoyanova
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Shomon Miah
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Jonathan Lucas
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Cara K Vaughan
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, UK; Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK.
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5
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Schiklenk C, Petrova B, Kschonsak M, Hassler M, Klein C, Gibson TJ, Haering CH. Control of mitotic chromosome condensation by the fission yeast transcription factor Zas1. J Cell Biol 2018; 217:2383-2401. [PMID: 29735745 PMCID: PMC6028546 DOI: 10.1083/jcb.201711097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 03/28/2018] [Accepted: 04/17/2018] [Indexed: 01/05/2023] Open
Abstract
How chromosomes compact into rod-shaped structures is a longstanding unresolved question of cell biology. Schiklenk et al. identify the transcription factor Zas1 as a central regulator of mitotic chromosome condensation in fission yeast and show that it uses a conserved transactivation domain–based mechanism to control gene expression. Although the formation of rod-shaped chromosomes is vital for the correct segregation of eukaryotic genomes during cell divisions, the molecular mechanisms that control the chromosome condensation process have remained largely unknown. Here, we identify the C2H2 zinc-finger transcription factor Zas1 as a key regulator of mitotic condensation dynamics in a quantitative live-cell microscopy screen of the fission yeast Schizosaccharomyces pombe. By binding to specific DNA target sequences in their promoter regions, Zas1 controls expression of the Cnd1 subunit of the condensin protein complex and several other target genes, whose combined misregulation in zas1 mutants results in defects in chromosome condensation and segregation. Genetic and biochemical analysis reveals an evolutionarily conserved transactivation domain motif in Zas1 that is pivotal to its function in gene regulation. Our results suggest that this motif, together with the Zas1 C-terminal helical domain to which it binds, creates a cis/trans switch module for transcriptional regulation of genes that control chromosome condensation.
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Affiliation(s)
- Christoph Schiklenk
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Boryana Petrova
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Marc Kschonsak
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Markus Hassler
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Carlo Klein
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Toby J Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Christian H Haering
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany .,Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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Leber V, Nans A, Singleton MR. Structural basis for assembly of the CBF3 kinetochore complex. EMBO J 2018; 37:269-281. [PMID: 29212814 PMCID: PMC5771398 DOI: 10.15252/embj.201798134] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/30/2017] [Accepted: 11/20/2017] [Indexed: 11/09/2022] Open
Abstract
Eukaryotic chromosomes contain a specialised region known as the centromere, which forms the platform for kinetochore assembly and microtubule attachment. The centromere is distinguished by the presence of nucleosomes containing the histone H3 variant, CENP-A. In budding yeast, centromere establishment begins with the recognition of a specific DNA sequence by the CBF3 complex. This in turn facilitates CENP-ACse4 nucleosome deposition and kinetochore assembly. Here, we describe a 3.6 Å single-particle cryo-EM reconstruction of the core CBF3 complex, incorporating the sequence-specific DNA-binding protein Cep3 together with regulatory subunits Ctf13 and Skp1. This provides the first structural data on Ctf13, defining it as an F-box protein of the leucine-rich-repeat family, and demonstrates how a novel F-box-mediated interaction between Ctf13 and Skp1 is responsible for initial assembly of the CBF3 complex.
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Affiliation(s)
- Vera Leber
- Structural Biology of Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
| | - Andrea Nans
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, London, UK
| | - Martin R Singleton
- Structural Biology of Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
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Kobayashi N, Suzuki Y, Schoenfeld LW, Müller CA, Nieduszynski C, Wolfe KH, Tanaka TU. Discovery of an unconventional centromere in budding yeast redefines evolution of point centromeres. Curr Biol 2015; 25:2026-33. [PMID: 26166782 PMCID: PMC4533239 DOI: 10.1016/j.cub.2015.06.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 04/26/2015] [Accepted: 06/10/2015] [Indexed: 11/30/2022]
Abstract
Centromeres are the chromosomal regions promoting kinetochore assembly for chromosome segregation. In many eukaryotes, the centromere consists of up to mega base pairs of DNA. On such “regional centromeres,” kinetochore assembly is mainly defined by epigenetic regulation [1]. By contrast, a clade of budding yeasts (Saccharomycetaceae) has a “point centromere” of 120–200 base pairs of DNA, on which kinetochore assembly is defined by the consensus DNA sequence [2, 3]. During evolution, budding yeasts acquired point centromeres, which replaced ancestral, regional centromeres [4]. All known point centromeres among different yeast species share common consensus DNA elements (CDEs) [5, 6], implying that they evolved only once and stayed essentially unchanged throughout evolution. Here, we identify a yeast centromere that challenges this view: that of the budding yeast Naumovozyma castellii is the first unconventional point centromere with unique CDEs. The N. castellii centromere CDEs are essential for centromere function but have different DNA sequences from CDEs in other point centromeres. Gene order analyses around N. castellii centromeres indicate their unique, and separate, evolutionary origin. Nevertheless, they are still bound by the ortholog of the CBF3 complex, which recognizes CDEs in other point centromeres. The new type of point centromere originated prior to the divergence between N. castellii and its close relative Naumovozyma dairenensis and disseminated to all N. castellii chromosomes through extensive genome rearrangement. Thus, contrary to the conventional view, point centromeres can undergo rapid evolutionary changes. These findings give new insights into the evolution of point centromeres. A new type of point centromere has been identified in budding yeast N. castellii Its DNA sequence and evolutionary origin are different from other point centromeres N. castellii centromeres are bound by CBF3 that recognizes other point centromeres Contrary to the conventional view, point centromeres can change rapidly in evolution
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Affiliation(s)
- Norihiko Kobayashi
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Yutaka Suzuki
- Department of Computational Biology, School of Frontier Medicine, University of Tokyo, Chiba 277-8562, Japan
| | - Lori W Schoenfeld
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Carolin A Müller
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Conrad Nieduszynski
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Kenneth H Wolfe
- UCD Conway Institute, School of Medicine and Medical Science, University College Dublin, Dublin 4, Ireland
| | - Tomoyuki U Tanaka
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
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Westermann S, Schleiffer A. Family matters: structural and functional conservation of centromere-associated proteins from yeast to humans. Trends Cell Biol 2013; 23:260-9. [DOI: 10.1016/j.tcb.2013.01.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 01/22/2013] [Accepted: 01/31/2013] [Indexed: 01/19/2023]
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Perriches T, Singleton MR. Structure of yeast kinetochore Ndc10 DNA-binding domain reveals unexpected evolutionary relationship to tyrosine recombinases. J Biol Chem 2012; 287:5173-9. [PMID: 22215672 PMCID: PMC3281669 DOI: 10.1074/jbc.c111.318501] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 12/21/2011] [Indexed: 11/06/2022] Open
Abstract
We have solved the x-ray structure of the N-terminal half of the yeast kinetochore protein Ndc10 at 1.9 Å resolution. This essential protein is a key constituent of the budding yeast centromere and is essential for the recruitment of the centromeric nucleosome and establishment of the kinetochore. The fold of the protein shows unexpected similarities to the tyrosine recombinase/λ-integrase family of proteins, most notably Cre, with some variation in the relative position of the subdomains. This finding offers new insights into kinetochore evolution and the adaptation of a well studied protein fold to a novel role. By comparison with tyrosine recombinases and mutagenesis studies, we have been able to define some of the key DNA-binding motifs.
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Affiliation(s)
- Thibaud Perriches
- From the Macromolecular Structure and Function Laboratory, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, United Kingdom
| | - Martin R. Singleton
- From the Macromolecular Structure and Function Laboratory, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, United Kingdom
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10
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Cho US, Harrison SC. Ndc10 is a platform for inner kinetochore assembly in budding yeast. Nat Struct Mol Biol 2011; 19:48-55. [PMID: 22139014 PMCID: PMC3252399 DOI: 10.1038/nsmb.2178] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 09/20/2011] [Indexed: 01/21/2023]
Abstract
Kinetochores link centromeric DNA to spindle microtubules and ensure faithful chromosome segregation during mitosis. In point-centromere yeasts, the CBF3 complex, Skp1:Ctf13:(Cep3)2:(Ndc10)2, recognizes a conserved centromeric DNA element through contacts made by Cep3 and Ndc10. We describe here the five-domain organization of Kluyveromyces lactis Ndc10 and the structure at 2.8 Å resolution of domains I–II (residues 1–402) bound to DNA. The structure resembles tyrosine DNA recombinases, although it lacks both endonuclease and ligase activities. Structural and biochemical data demonstrate that each subunit of the Ndc10 dimer binds a separate fragment of DNA, suggesting that Ndc10 stabilizes a DNA loop at the centromere. We describe in vitro association experiments showing that specific domains of Ndc10 interact with each of the known inner-kinetochore proteins or protein complexes in budding yeast. We propose that Ndc10 provides a central platform for inner-kinetochore assembly.
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Affiliation(s)
- Uhn-Soo Cho
- Jack and Eileen Connors Structural Biology Laboratory and Howard Hughes Medical Institute, Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
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Cho US, Corbett KD, Al-Bassam J, Bellizzi JJ, De Wulf P, Espelin CW, Miranda JJ, Simons K, Wei RR, Sorger PK, Harrison SC. Molecular structures and interactions in the yeast kinetochore. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2011; 75:395-401. [PMID: 21467141 DOI: 10.1101/sqb.2010.75.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Kinetochores are the elaborate protein assemblies that attach chromosomes to spindle microtubules in mitosis and meiosis. The kinetochores of point-centromere yeast appear to represent an elementary module, which repeats a number of times in kinetochores assembled on regional centromeres. Structural analyses of the discrete protein subcomplexes that make up the budding-yeast kinetochore have begun to reveal principles of kinetochore architecture and to uncover molecular mechanisms underlying functions such as transmission of tension and establishment and maintenance of bipolar attachment. The centromeric DNA is probably wrapped into a compact organization, not only by a conserved, centromeric nucleosome, but also by interactions among various other DNA-bound kinetochore components. The rod-like, heterotetrameric Ndc80 complex, roughly 600 Å long, appears to extend from the DNA-proximal assembly to the plus end of a microtubule, to which one end of the complex is known to bind. Ongoing structural studies will clarify the roles of a number of other well-defined complexes.
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Affiliation(s)
- U-S Cho
- Jack and Eileen Connors Structural Biology Laboratory, Harvard Medical School, Boston, Massachusetts 02115, USA
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Abstract
Chromosome segregation in eukaryotes requires a large molecular assembly termed the kinetochore to attach chromosomes to spindle microtubules. Recent work has made substantial progress in defining the composition and activities of the kinetochore, but much remains to be learned about its macromolecular structure. This commentary discusses recent insights into structural features of the kinetochore, how these inform our understanding of its biological function, and the key challenges for the future.
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Affiliation(s)
- Julie P I Welburn
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142, USA.
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13
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Bouck DC, Joglekar AP, Bloom KS. Design features of a mitotic spindle: balancing tension and compression at a single microtubule kinetochore interface in budding yeast. Annu Rev Genet 2009; 42:335-59. [PMID: 18680435 DOI: 10.1146/annurev.genet.42.110807.091620] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Accurate segregation of duplicated chromosomes ensures that daughter cells get one and only one copy of each chromosome. Errors in chromosome segregation result in aneuploidy and have severe consequences on human health. Incorrect chromosome number and chromosomal instability are hallmarks of tumor cells. Hence, segregation errors are thought to be a major cause of tumorigenesis. A study of the physical mechanical basis of chromosome segregation is essential to understand the processes that can lead to errors. Tremendous progress has been made in recent years in identifying the proteins necessary for chromosome movement and segregation, but the mechanism and structure of critical force generating components and the molecular basis of centromere stiffness remain poorly understood.
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Affiliation(s)
- David C Bouck
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA.
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14
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Cohen RL, Espelin CW, De Wulf P, Sorger PK, Harrison SC, Simons KT. Structural and functional dissection of Mif2p, a conserved DNA-binding kinetochore protein. Mol Biol Cell 2008; 19:4480-91. [PMID: 18701705 DOI: 10.1091/mbc.e08-03-0297] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Mif2p is the budding-yeast orthologue of the mammalian centromere-binding protein CENP-C. We have mapped domains of Saccharomyces cerevisiae Mif2p and studied the phenotyptic consequences of their deletion. Using chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assays, we have further shown that Mif2p binds in the CDEIII region of the budding-yeast centromere, probably in close spatial association with Ndc10p. Moreover, ChIP experiments show that Mif2p recruits to yeast kinetochores a substantial subset of inner and outer kinetochore proteins, but not the Ndc80 or Spc105 complexes. We have determined the crystal structure of the C-terminal, dimerization domain of Mif2p. It has a "cupin" fold, extremely similar both in polypeptide chain conformation and in dimer geometry to the dimerization domain of a bacterial transcription factor. The Mif2p dimer seems to be part of an enhanceosome-like structure that nucleates kinetochore assembly in budding yeast.
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Affiliation(s)
- R L Cohen
- Jack and Eileen Connors Structural Biology Laboratory, Harvard Medical School, Boston, MA 02115, USA
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15
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Current awareness on yeast. Yeast 2008. [DOI: 10.1002/yea.1563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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