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Sun W, Dong Q, Li X, Gao J, Ye X, Hu C, Li F, Chen Y. The SUN-family protein Sad1 mediates heterochromatin spatial organization through interaction with histone H2A-H2B. Nat Commun 2024; 15:4322. [PMID: 38773107 PMCID: PMC11109203 DOI: 10.1038/s41467-024-48418-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 04/30/2024] [Indexed: 05/23/2024] Open
Abstract
Heterochromatin is generally associated with the nuclear periphery, but how the spatial organization of heterochromatin is regulated to ensure epigenetic silencing remains unclear. Here we found that Sad1, an inner nuclear membrane SUN-family protein in fission yeast, interacts with histone H2A-H2B but not H3-H4. We solved the crystal structure of the histone binding motif (HBM) of Sad1 in complex with H2A-H2B, revealing the intimate contacts between Sad1HBM and H2A-H2B. Structure-based mutagenesis studies revealed that the H2A-H2B-binding activity of Sad1 is required for the dynamic distribution of Sad1 throughout the nuclear envelope (NE). The Sad1-H2A-H2B complex mediates tethering telomeres and the mating-type locus to the NE. This complex is also important for heterochromatin silencing. Mechanistically, H2A-H2B enhances the interaction between Sad1 and HDACs, including Clr3 and Sir2, to maintain epigenetic identity of heterochromatin. Interestingly, our results suggest that Sad1 exhibits the histone-enhanced liquid-liquid phase separation property, which helps recruit heterochromatin factors to the NE. Our results uncover an unexpected role of SUN-family proteins in heterochromatin regulation and suggest a nucleosome-independent role of H2A-H2B in regulating Sad1's functionality.
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Affiliation(s)
- Wenqi Sun
- State Key Laboratory of Molecular Biology, Key Laboratory of Epigenetic Regulation and Intervention, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Qianhua Dong
- Department of Biology, New York University, New York, NY, USA
| | - Xueqing Li
- State Key Laboratory of Molecular Biology, Key Laboratory of Epigenetic Regulation and Intervention, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jinxin Gao
- Department of Biology, New York University, New York, NY, USA
| | - Xianwen Ye
- University of Chinese Academy of Sciences, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, China
| | - Chunyi Hu
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, Singapore
| | - Fei Li
- Department of Biology, New York University, New York, NY, USA.
| | - Yong Chen
- State Key Laboratory of Molecular Biology, Key Laboratory of Epigenetic Regulation and Intervention, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, China.
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2
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Lai C, Xu L, Dai S. The nuclear export protein exportin-1 in solid malignant tumours: From biology to clinical trials. Clin Transl Med 2024; 14:e1684. [PMID: 38783482 PMCID: PMC11116501 DOI: 10.1002/ctm2.1684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 04/15/2024] [Accepted: 04/19/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Exportin-1 (XPO1), a crucial protein regulating nuclear-cytoplasmic transport, is frequently overexpressed in various cancers, driving tumor progression and drug resistance. This makes XPO1 an attractive therapeutic target. Over the past few decades, the number of available nuclear export-selective inhibitors has been increasing. Only KPT-330 (selinexor) has been successfully used for treating haematological malignancies, and KPT-8602 (eltanexor) has been used for treating haematologic tumours in clinical trials. However, the use of nuclear export-selective inhibitors for the inhibition of XPO1 expression has yet to be thoroughly investigated in clinical studies and therapeutic outcomes for solid tumours. METHODS We collected numerous literatures to explain the efficacy of XPO1 Inhibitors in preclinical and clinical studies of a wide range of solid tumours. RESULTS In this review, we focus on the nuclear export function of XPO1 and results from clinical trials of its inhibitors in solid malignant tumours. We summarized the mechanism of action and therapeutic potential of XPO1 inhibitors, as well as adverse effects and response biomarkers. CONCLUSION XPO1 inhibition has emerged as a promising therapeutic strategy in the fight against cancer, offering a novel approach to targeting tumorigenic processes and overcoming drug resistance. SINE compounds have demonstrated efficacy in a wide range of solid tumours, and ongoing research is focused on optimizing their use, identifying response biomarkers, and developing effective combination therapies. KEY POINTS Exportin-1 (XPO1) plays a critical role in mediating nucleocytoplasmic transport and cell cycle. XPO1 dysfunction promotes tumourigenesis and drug resistance within solid tumours. The therapeutic potential and ongoing researches on XPO1 inhibitors in the treatment of solid tumours. Additional researches are essential to address safety concerns and identify biomarkers for predicting patient response to XPO1 inhibitors.
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Affiliation(s)
- Chuanxi Lai
- Department of Colorectal SurgerySir Run Run Shaw HospitalSchool of MedicineZhejiang UniversityHangzhouChina
- Key Laboratory of Biotherapy of Zhejiang ProvinceHangzhouChina
| | - Lingna Xu
- Department of Colorectal SurgerySir Run Run Shaw HospitalSchool of MedicineZhejiang UniversityHangzhouChina
- Key Laboratory of Biotherapy of Zhejiang ProvinceHangzhouChina
| | - Sheng Dai
- Department of Colorectal SurgerySir Run Run Shaw HospitalSchool of MedicineZhejiang UniversityHangzhouChina
- Key Laboratory of Biotherapy of Zhejiang ProvinceHangzhouChina
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3
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Cissé OH, Curran SJ, Folco HD, Liu Y, Bishop L, Wang H, Fischer ER, Davis AS, Combs C, Thapar S, Dekker JP, Grewal S, Cushion M, Ma L, Kovacs JA. Regional centromere configuration in the fungal pathogens of the Pneumocystis genus. mBio 2024; 15:e0318523. [PMID: 38380929 PMCID: PMC10936427 DOI: 10.1128/mbio.03185-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
Centromeres are constricted chromosomal regions that are essential for cell division. In eukaryotes, centromeres display a remarkable architectural and genetic diversity. The basis of centromere-accelerated evolution remains elusive. Here, we focused on Pneumocystis species, a group of mammalian-specific fungal pathogens that form a sister taxon with that of the Schizosaccharomyces pombe, an important genetic model for centromere biology research. Methods allowing reliable continuous culture of Pneumocystis species do not currently exist, precluding genetic manipulation. CENP-A, a variant of histone H3, is the epigenetic marker that defines centromeres in most eukaryotes. Using heterologous complementation, we show that the Pneumocystis CENP-A ortholog is functionally equivalent to CENP-ACnp1 of S. pombe. Using organisms from a short-term in vitro culture or infected animal models and chromatin immunoprecipitation (ChIP)-Seq, we identified CENP-A bound regions in two Pneumocystis species that diverged ~35 million years ago. Each species has a unique short regional centromere (<10 kb) flanked by heterochromatin in 16-17 monocentric chromosomes. They span active genes and lack conserved DNA sequence motifs and repeats. These features suggest an epigenetic specification of centromere function. Analysis of centromeric DNA across multiple Pneumocystis species suggests a vertical transmission at least 100 million years ago. The common ancestry of Pneumocystis and S. pombe centromeres is untraceable at the DNA level, but the overall architectural similarity could be the result of functional constraint for successful chromosomal segregation.IMPORTANCEPneumocystis species offer a suitable genetic system to study centromere evolution in pathogens because of their phylogenetic proximity with the non-pathogenic yeast S. pombe, a popular model for cell biology. We used this system to explore how centromeres have evolved after the divergence of the two clades ~ 460 million years ago. To address this question, we established a protocol combining short-term culture and ChIP-Seq to characterize centromeres in multiple Pneumocystis species. We show that Pneumocystis have short epigenetic centromeres that function differently from those in S. pombe.
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Affiliation(s)
- Ousmane H. Cissé
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Shelly J. Curran
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - H. Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Yueqin Liu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Lisa Bishop
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Honghui Wang
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Elizabeth R. Fischer
- Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - A. Sally Davis
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Christian Combs
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Sabrina Thapar
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - John P. Dekker
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, National Institute of Allergy, and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Shiv Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Melanie Cushion
- Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Liang Ma
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Joseph A. Kovacs
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
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4
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Ito N, Sakamoto T, Oko Y, Sato H, Hanamata S, Sakamoto Y, Matsunaga S. Nuclear pore complex proteins are involved in centromere distribution. iScience 2024; 27:108855. [PMID: 38318384 PMCID: PMC10839643 DOI: 10.1016/j.isci.2024.108855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 11/28/2023] [Accepted: 01/05/2024] [Indexed: 02/07/2024] Open
Abstract
The subnuclear distribution of centromeres is cooperatively regulated by condensin II and the linker of nucleoskeleton and cytoskeleton (LINC) complex. However, other nuclear membrane structures and nuclear proteins are probably involved in centromere dynamics and distribution. Here, we focused on the nuclear pore complex (NPC), which is known to regulate gene expression, transcription memory, and chromatin structure in addition to transport between the cytoplasm and nucleoplasm. We report here that some nucleoporins (Nups), including Nup85, Nup133, CG1, Nup93b, and NUA, are involved in centromere scattering in Arabidopsis thaliana. In addition, the centromere dynamics after metaphase in nup mutants were found to be similar to that of the condensin II mutant. Furthermore, both biochemical and genetic approaches showed that the Nups interact with the LINC complex. These results suggest that Nups regulate centromere scattering cooperatively with condensin II and the LINC complex.
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Affiliation(s)
- Nanami Ito
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Takuya Sakamoto
- Department of Science, Faculty of Science, Kanagawa University, Yokohama, Kanagawa 221-8686, Japan
- Faculty of Science and Technology, Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Yuka Oko
- Faculty of Science and Technology, Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Hikaru Sato
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Shigeru Hanamata
- Department of Science, Faculty of Science, Kanagawa University, Yokohama, Kanagawa 221-8686, Japan
| | - Yuki Sakamoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Sachihiro Matsunaga
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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5
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Bredeson JV, Mudd AB, Medina-Ruiz S, Mitros T, Smith OK, Miller KE, Lyons JB, Batra SS, Park J, Berkoff KC, Plott C, Grimwood J, Schmutz J, Aguirre-Figueroa G, Khokha MK, Lane M, Philipp I, Laslo M, Hanken J, Kerdivel G, Buisine N, Sachs LM, Buchholz DR, Kwon T, Smith-Parker H, Gridi-Papp M, Ryan MJ, Denton RD, Malone JH, Wallingford JB, Straight AF, Heald R, Hockemeyer D, Harland RM, Rokhsar DS. Conserved chromatin and repetitive patterns reveal slow genome evolution in frogs. Nat Commun 2024; 15:579. [PMID: 38233380 PMCID: PMC10794172 DOI: 10.1038/s41467-023-43012-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 10/27/2023] [Indexed: 01/19/2024] Open
Abstract
Frogs are an ecologically diverse and phylogenetically ancient group of anuran amphibians that include important vertebrate cell and developmental model systems, notably the genus Xenopus. Here we report a high-quality reference genome sequence for the western clawed frog, Xenopus tropicalis, along with draft chromosome-scale sequences of three distantly related emerging model frog species, Eleutherodactylus coqui, Engystomops pustulosus, and Hymenochirus boettgeri. Frog chromosomes have remained remarkably stable since the Mesozoic Era, with limited Robertsonian (i.e., arm-preserving) translocations and end-to-end fusions found among the smaller chromosomes. Conservation of synteny includes conservation of centromere locations, marked by centromeric tandem repeats associated with Cenp-a binding surrounded by pericentromeric LINE/L1 elements. This work explores the structure of chromosomes across frogs, using a dense meiotic linkage map for X. tropicalis and chromatin conformation capture (Hi-C) data for all species. Abundant satellite repeats occupy the unusually long (~20 megabase) terminal regions of each chromosome that coincide with high rates of recombination. Both embryonic and differentiated cells show reproducible associations of centromeric chromatin and of telomeres, reflecting a Rabl-like configuration. Our comparative analyses reveal 13 conserved ancestral anuran chromosomes from which contemporary frog genomes were constructed.
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Affiliation(s)
- Jessen V Bredeson
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
- DOE-Joint Genome Institute, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Austin B Mudd
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Sofia Medina-Ruiz
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Therese Mitros
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Owen Kabnick Smith
- Department of Biochemistry, Stanford University School of Medicine, 279 Campus Drive, Beckman Center 409, Stanford, CA, 94305-5307, USA
| | - Kelly E Miller
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Jessica B Lyons
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Sanjit S Batra
- Computer Science Division, University of California Berkeley, 2626 Hearst Avenue, Berkeley, CA, 94720, USA
| | - Joseph Park
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Kodiak C Berkoff
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Christopher Plott
- HudsonAlpha Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Jane Grimwood
- HudsonAlpha Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Jeremy Schmutz
- HudsonAlpha Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Guadalupe Aguirre-Figueroa
- Department of Biochemistry, Stanford University School of Medicine, 279 Campus Drive, Beckman Center 409, Stanford, CA, 94305-5307, USA
| | - Mustafa K Khokha
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
| | - Maura Lane
- Pediatric Genomics Discovery Program, Departments of Pediatrics and Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06510, USA
| | - Isabelle Philipp
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Mara Laslo
- Department of Organismic and Evolutionary Biology, and Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
| | - James Hanken
- Department of Organismic and Evolutionary Biology, and Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
| | - Gwenneg Kerdivel
- Département Adaptation du Vivant, UMR 7221 CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Nicolas Buisine
- Département Adaptation du Vivant, UMR 7221 CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Laurent M Sachs
- Département Adaptation du Vivant, UMR 7221 CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Daniel R Buchholz
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Taejoon Kwon
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Heidi Smith-Parker
- Department of Integrative Biology, Patterson Labs, 2401 Speedway, University of Texas, Austin, TX, 78712, USA
| | - Marcos Gridi-Papp
- Department of Biological Sciences, University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA
| | - Michael J Ryan
- Department of Integrative Biology, Patterson Labs, 2401 Speedway, University of Texas, Austin, TX, 78712, USA
| | - Robert D Denton
- Department of Molecular and Cell Biology and Institute of Systems Genomics, University of Connecticut, 181 Auditorium Road, Unit 3197, Storrs, CT, 06269, USA
| | - John H Malone
- Department of Molecular and Cell Biology and Institute of Systems Genomics, University of Connecticut, 181 Auditorium Road, Unit 3197, Storrs, CT, 06269, USA
| | - John B Wallingford
- Department of Molecular Biosciences, Patterson Labs, 2401 Speedway, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Aaron F Straight
- Department of Biochemistry, Stanford University School of Medicine, 279 Campus Drive, Beckman Center 409, Stanford, CA, 94305-5307, USA
| | - Rebecca Heald
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
- Innovative Genomics Institute, University of California, Berkeley, CA, 94720, USA
- Chan-Zuckerberg BioHub, 499 Illinois Street, San Francisco, CA, 94158, USA
| | - Richard M Harland
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA
| | - Daniel S Rokhsar
- Department of Molecular and Cell Biology, Weill Hall, University of California, Berkeley, CA, 94720, USA.
- DOE-Joint Genome Institute, 1 Cyclotron Road, Berkeley, CA, 94720, USA.
- Innovative Genomics Institute, University of California, Berkeley, CA, 94720, USA.
- Chan-Zuckerberg BioHub, 499 Illinois Street, San Francisco, CA, 94158, USA.
- Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 9040495, Japan.
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6
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Strachan J, Leidecker O, Spanos C, Le Coz C, Chapman E, Arsenijevic A, Zhang H, Zhao N, Spoel SH, Bayne EH. SUMOylation regulates Lem2 function in centromere clustering and silencing. J Cell Sci 2023; 136:jcs260868. [PMID: 37970674 PMCID: PMC10730020 DOI: 10.1242/jcs.260868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 11/07/2023] [Indexed: 11/17/2023] Open
Abstract
Regulation by the small modifier SUMO is heavily dependent on spatial control of enzymes that mediate the attachment and removal of SUMO on substrate proteins. Here, we show that in the fission yeast Schizosaccharomyces pombe, delocalisation of the SUMO protease Ulp1 from the nuclear envelope results in centromeric defects that can be attributed to hyper-SUMOylation at the nuclear periphery. Unexpectedly, we find that although this localised hyper-SUMOylation impairs centromeric silencing, it can also enhance centromere clustering. Moreover, both effects are at least partially dependent on SUMOylation of the inner nuclear membrane protein Lem2. Lem2 has previously been implicated in diverse biological processes, including the promotion of both centromere clustering and silencing, but how these distinct activities are coordinated was unclear; our observations suggest a model whereby SUMOylation serves as a regulatory switch, modulating Lem2 interactions with competing partner proteins to balance its roles in alternative pathways. Our findings also reveal a previously unappreciated role for SUMOylation in promoting centromere clustering.
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Affiliation(s)
- Joanna Strachan
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Orsolya Leidecker
- Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, Cologne 50931, Germany
| | - Christos Spanos
- Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Clementine Le Coz
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Elliott Chapman
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Ana Arsenijevic
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Haidao Zhang
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Ning Zhao
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
| | - Steven H. Spoel
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Elizabeth H. Bayne
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK
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7
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Colin L, Reyes C, Berthezene J, Maestroni L, Modolo L, Toselli E, Chanard N, Schaak S, Cuvier O, Gachet Y, Coulon S, Bernard P, Tournier S. Condensin positioning at telomeres by shelterin proteins drives sister-telomere disjunction in anaphase. eLife 2023; 12:RP89812. [PMID: 37988290 PMCID: PMC10662949 DOI: 10.7554/elife.89812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023] Open
Abstract
The localization of condensin along chromosomes is crucial for their accurate segregation in anaphase. Condensin is enriched at telomeres but how and for what purpose had remained elusive. Here, we show that fission yeast condensin accumulates at telomere repeats through the balancing acts of Taz1, a core component of the shelterin complex that ensures telomeric functions, and Mit1, a nucleosome remodeler associated with shelterin. We further show that condensin takes part in sister-telomere separation in anaphase, and that this event can be uncoupled from the prior separation of chromosome arms, implying a telomere-specific separation mechanism. Consistent with a cis-acting process, increasing or decreasing condensin occupancy specifically at telomeres modifies accordingly the efficiency of their separation in anaphase. Genetic evidence suggests that condensin promotes sister-telomere separation by counteracting cohesin. Thus, our results reveal a shelterin-based mechanism that enriches condensin at telomeres to drive in cis their separation during mitosis.
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Affiliation(s)
- Léonard Colin
- CNRS - Laboratory of Biology and Modelling of the CellLyonFrance
- ENS de Lyon, Université Lyon, site Jacques MonodLyonFrance
| | - Celine Reyes
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Julien Berthezene
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Laetitia Maestroni
- CNRS, INSERM, Aix Marseille Université, Institut Paoli-Calmettes, CRCM, Equipe labellisée par la Ligue Nationale contre le CancerMarseilleFrance
| | - Laurent Modolo
- CNRS - Laboratory of Biology and Modelling of the CellLyonFrance
- ENS de Lyon, Université Lyon, site Jacques MonodLyonFrance
| | - Esther Toselli
- CNRS - Laboratory of Biology and Modelling of the CellLyonFrance
- ENS de Lyon, Université Lyon, site Jacques MonodLyonFrance
| | - Nicolas Chanard
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
- CBI, MCD-UMR5077, CNRS, Chromatin Dynamics TeamToulouseFrance
| | - Stephane Schaak
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
- CBI, MCD-UMR5077, CNRS, Chromatin Dynamics TeamToulouseFrance
| | - Olivier Cuvier
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
- CBI, MCD-UMR5077, CNRS, Chromatin Dynamics TeamToulouseFrance
| | - Yannick Gachet
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
| | - Stephane Coulon
- CNRS, INSERM, Aix Marseille Université, Institut Paoli-Calmettes, CRCM, Equipe labellisée par la Ligue Nationale contre le CancerMarseilleFrance
| | - Pascal Bernard
- CNRS - Laboratory of Biology and Modelling of the CellLyonFrance
- ENS de Lyon, Université Lyon, site Jacques MonodLyonFrance
| | - Sylvie Tournier
- MCD, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPSToulouseFrance
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8
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London N, Medina-Pritchard B, Spanos C, Rappsilber J, Jeyaprakash AA, Allshire RC. Direct recruitment of Mis18 to interphase spindle pole bodies promotes CENP-A chromatin assembly. Curr Biol 2023; 33:4187-4201.e6. [PMID: 37714149 DOI: 10.1016/j.cub.2023.08.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/04/2023] [Accepted: 08/22/2023] [Indexed: 09/17/2023]
Abstract
CENP-A chromatin specifies mammalian centromere identity, and its chaperone HJURP replenishes CENP-A when recruited by the Mis18 complex (Mis18C) via M18BP1/KNL2 to CENP-C at kinetochores during interphase. However, the Mis18C recruitment mechanism remains unresolved in species lacking M18BP1, such as fission yeast. Fission yeast centromeres cluster at G2 spindle pole bodies (SPBs) when CENP-ACnp1 is replenished and where Mis18C also localizes. We show that SPBs play an unexpected role in concentrating Mis18C near centromeres through the recruitment of Mis18 by direct binding to the major SPB linker of nucleoskeleton and cytoskeleton (LINC) component Sad1. Mis18C recruitment by Sad1 is important for CENP-ACnp1 chromatin establishment and acts in parallel with a CENP-C-mediated Mis18C recruitment pathway to maintain centromeric CENP-ACnp1 but operates independently of Sad1-mediated centromere clustering. SPBs therefore provide a non-chromosomal scaffold for both Mis18C recruitment and centromere clustering during G2. This centromere-independent Mis18-SPB recruitment provides a mechanism that governs de novo CENP-ACnp1 chromatin assembly by the proximity of appropriate sequences to SPBs and highlights how nuclear spatial organization influences centromere identity.
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Affiliation(s)
- Nitobe London
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Bethan Medina-Pritchard
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Christos Spanos
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Juri Rappsilber
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK; Institute of Biotechnology, Technische Universität, 13355 Berlin, Germany
| | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK; Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK.
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9
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Bailey MLP, Surovtsev I, Williams JF, Yan H, Yuan T, Li K, Duseau K, Mochrie SGJ, King MC. Loops and the activity of loop extrusion factors constrain chromatin dynamics. Mol Biol Cell 2023; 34:ar78. [PMID: 37126401 PMCID: PMC10398873 DOI: 10.1091/mbc.e23-04-0119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/02/2023] Open
Abstract
The chromosomes-DNA polymers and their binding proteins-are compacted into a spatially organized, yet dynamic, three-dimensional structure. Recent genome-wide chromatin conformation capture experiments reveal a hierarchical organization of the DNA structure that is imposed, at least in part, by looping interactions arising from the activity of loop extrusion factors. The dynamics of chromatin reflects the response of the polymer to a combination of thermal fluctuations and active processes. However, how chromosome structure and enzymes acting on chromatin together define its dynamics remains poorly understood. To gain insight into the structure-dynamics relationship of chromatin, we combine high-precision microscopy in living Schizosaccharomyces pombe cells with systematic genetic perturbations and Rouse model polymer simulations. We first investigated how the activity of two loop extrusion factors, the cohesin and condensin complexes, influences chromatin dynamics. We observed that deactivating cohesin, or to a lesser extent condensin, increased chromatin mobility, suggesting that loop extrusion constrains rather than agitates chromatin motion. Our corresponding simulations reveal that the introduction of loops is sufficient to explain the constraining activity of loop extrusion factors, highlighting that the conformation adopted by the polymer plays a key role in defining its dynamics. Moreover, we find that the number of loops or residence times of loop extrusion factors influence the dynamic behavior of the chromatin polymer. Last, we observe that the activity of the INO80 chromatin remodeler, but not the SWI/SNF or RSC complexes, is critical for ATP-dependent chromatin mobility in fission yeast. Taking the data together, we suggest that thermal and INO80-dependent activities exert forces that drive chromatin fluctuations, which are constrained by the organization of the chromosome into loops.
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Affiliation(s)
- Mary Lou P. Bailey
- Department of Applied Physics, Yale University, New Haven, CT 06511
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
| | - Ivan Surovtsev
- Department of Physics, Yale University, New Haven, CT 06511
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | | | - Hao Yan
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Physics, Yale University, New Haven, CT 06511
| | - Tianyu Yuan
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Physics, Yale University, New Haven, CT 06511
| | - Kevin Li
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - Katherine Duseau
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - Simon G. J. Mochrie
- Department of Applied Physics, Yale University, New Haven, CT 06511
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Physics, Yale University, New Haven, CT 06511
| | - Megan C. King
- Integrated Graduate Program in Physics Engineering Biology, Yale University, New Haven, CT 06511
- Department of Molecular, Cell and Developmental Biology, Yale University, New Haven, CT 06511
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
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10
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Solé M, Pascual Á, Anton E, Blanco J, Sarrate Z. The courtship choreography of homologous chromosomes: timing and mechanisms of DSB-independent pairing. Front Cell Dev Biol 2023; 11:1191156. [PMID: 37377734 PMCID: PMC10291267 DOI: 10.3389/fcell.2023.1191156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Meiosis involves deep changes in the spatial organisation and interactions of chromosomes enabling the two primary functions of this process: increasing genetic diversity and reducing ploidy level. These two functions are ensured by crucial events such as homologous chromosomal pairing, synapsis, recombination and segregation. In most sexually reproducing eukaryotes, homologous chromosome pairing depends on a set of mechanisms, some of them associated with the repair of DNA double-strand breaks (DSBs) induced at the onset of prophase I, and others that operate before DSBs formation. In this article, we will review various strategies utilised by model organisms for DSB-independent pairing. Specifically, we will focus on mechanisms such as chromosome clustering, nuclear and chromosome movements, as well as the involvement of specific proteins, non-coding RNA, and DNA sequences.
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Affiliation(s)
| | | | | | - Joan Blanco
- *Correspondence: Joan Blanco, ; Zaida Sarrate,
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11
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Cissé OH, Curran S, Folco HD, Liu Y, Bishop L, Wang H, Fischer ER, Davis AS, Babb-Biernacki S, Doyle VP, Richards JK, Hassan SA, Dekker JP, Khil PP, Brenchley JM, Grewal S, Cushion M, Ma L, Kovacs JA. The Host Adapted Fungal Pathogens of Pneumocystis Genus Utilize Genic Regional Centromeres. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.12.540427. [PMID: 37425787 PMCID: PMC10327204 DOI: 10.1101/2023.05.12.540427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Centromeres are genomic regions that coordinate accurate chromosomal segregation during mitosis and meiosis. Yet, despite their essential function, centromeres evolve rapidly across eukaryotes. Centromeres are often the sites of chromosomal breaks which contribute to genome shuffling and promote speciation by inhibiting gene flow. How centromeres form in strongly host-adapted fungal pathogens has yet to be investigated. Here, we characterized the centromere structures in closely related species of mammalian-specific pathogens of the fungal phylum of Ascomycota. Methods allowing reliable continuous culture of Pneumocystis species do not currently exist, precluding genetic manipulation. CENP-A, a variant of histone H3, is the epigenetic marker that defines centromeres in most eukaryotes. Using heterologous complementation, we show that the Pneumocystis CENP-A ortholog is functionally equivalent to CENP-ACnp1 of Schizosaccharomyces pombe. Using organisms from a short-term in vitro culture or infected animal models and ChIP-seq, we identified centromeres in three Pneumocystis species that diverged ~100 million years ago. Each species has a unique short regional centromere (< 10kb) flanked by heterochromatin in 16-17 monocentric chromosomes. They span active genes and lack conserved DNA sequence motifs and repeats. CENP-C, a scaffold protein that links the inner centromere to the kinetochore appears dispensable in one species, suggesting a kinetochore rewiring. Despite the loss of DNA methyltransferases, 5-methylcytosine DNA methylation occurs in these species, though not related to centromere function. These features suggest an epigenetic specification of centromere function.
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Affiliation(s)
- Ousmane H Cissé
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Shelly Curran
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - H Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Yueqin Liu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Lisa Bishop
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Honghui Wang
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Elizabeth R Fischer
- Microscopy Unit, Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - A Sally Davis
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, USA
| | - Spenser Babb-Biernacki
- Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Vinson P Doyle
- Department of Plant Pathology and Crop Physiology, Lousiana State University AgCenter, Baton Rouge, Louisiana, USA
| | - Jonathan K Richards
- Department of Plant Pathology and Crop Physiology, Lousiana State University AgCenter, Baton Rouge, Louisiana, USA
| | - Sergio A Hassan
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - John P Dekker
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, National Institute of Allergy, and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Pavel P Khil
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, National Institute of Allergy, and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Jason M Brenchley
- Laboratory of Viral Diseases, National Institute of Allergy, and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Shiv Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Melanie Cushion
- Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Liang Ma
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Joseph A Kovacs
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
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12
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Mytlis A, Levy K, Elkouby YM. The many faces of the bouquet centrosome MTOC in meiosis and germ cell development. Curr Opin Cell Biol 2023; 81:102158. [PMID: 36913831 DOI: 10.1016/j.ceb.2023.102158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/28/2022] [Accepted: 02/12/2023] [Indexed: 03/13/2023]
Abstract
Meiotic chromosomal pairing is facilitated by a conserved cytoskeletal organization. Telomeres associate with perinuclear microtubules via Sun/KASH complexes on the nuclear envelope (NE) and dynein. Telomere sliding on perinuclear microtubules contributes to chromosome homology searches and is essential for meiosis. Telomeres ultimately cluster on the NE, facing the centrosome, in a configuration called the chromosomal bouquet. Here, we discuss novel components and functions of the bouquet microtubule organizing center (MTOC) in meiosis, but also broadly in gamete development. The cellular mechanics of chromosome movements and the bouquet MTOC dynamics are striking. The newly identified zygotene cilium mechanically anchors the bouquet centrosome and completes the bouquet MTOC machinery in zebrafish and mice. We hypothesize that various centrosome anchoring strategies evolved in different species. Evidence suggests that the bouquet MTOC machinery is a cellular organizer, linking meiotic mechanisms with gamete development and morphogenesis. We highlight this cytoskeletal organization as a new platform for creating a holistic understanding of early gametogenesis, with direct implications to fertility and reproduction.
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Affiliation(s)
- Avishag Mytlis
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem Faculty of Medicine, Ein-Kerem Campus, Jerusalem, 9112102, Israel; Institute for Medical Research - Israel-Canada (IMRIC), Ein-Kerem Campus, Jerusalem 9112102, Israel
| | - Karine Levy
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem Faculty of Medicine, Ein-Kerem Campus, Jerusalem, 9112102, Israel; Institute for Medical Research - Israel-Canada (IMRIC), Ein-Kerem Campus, Jerusalem 9112102, Israel
| | - Yaniv M Elkouby
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem Faculty of Medicine, Ein-Kerem Campus, Jerusalem, 9112102, Israel; Institute for Medical Research - Israel-Canada (IMRIC), Ein-Kerem Campus, Jerusalem 9112102, Israel.
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13
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Pennarun G, Picotto J, Bertrand P. Close Ties between the Nuclear Envelope and Mammalian Telomeres: Give Me Shelter. Genes (Basel) 2023; 14:genes14040775. [PMID: 37107534 PMCID: PMC10137478 DOI: 10.3390/genes14040775] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 04/29/2023] Open
Abstract
The nuclear envelope (NE) in eukaryotic cells is essential to provide a protective compartment for the genome. Beside its role in connecting the nucleus with the cytoplasm, the NE has numerous important functions including chromatin organization, DNA replication and repair. NE alterations have been linked to different human diseases, such as laminopathies, and are a hallmark of cancer cells. Telomeres, the ends of eukaryotic chromosomes, are crucial for preserving genome stability. Their maintenance involves specific telomeric proteins, repair proteins and several additional factors, including NE proteins. Links between telomere maintenance and the NE have been well established in yeast, in which telomere tethering to the NE is critical for their preservation and beyond. For a long time, in mammalian cells, except during meiosis, telomeres were thought to be randomly localized throughout the nucleus, but recent advances have uncovered close ties between mammalian telomeres and the NE that play important roles for maintaining genome integrity. In this review, we will summarize these connections, with a special focus on telomere dynamics and the nuclear lamina, one of the main NE components, and discuss the evolutionary conservation of these mechanisms.
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Affiliation(s)
- Gaëlle Pennarun
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
| | - Julien Picotto
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
| | - Pascale Bertrand
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
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14
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Choudhary K, Kupiec M. The cohesin complex of yeasts: sister chromatid cohesion and beyond. FEMS Microbiol Rev 2023; 47:6825453. [PMID: 36370456 DOI: 10.1093/femsre/fuac045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022] Open
Abstract
Each time a cell divides, it needs to duplicate the genome and then separate the two copies. In eukaryotes, which usually have more than one linear chromosome, this entails tethering the two newly replicated DNA molecules, a phenomenon known as sister chromatid cohesion (SCC). Cohesion ensures proper chromosome segregation to separate poles during mitosis. SCC is achieved by the presence of the cohesin complex. Besides its canonical function, cohesin is essential for chromosome organization and DNA damage repair. Surprisingly, yeast cohesin is loaded in G1 before DNA replication starts but only acquires its binding activity during DNA replication. Work in microorganisms, such as Saccharomyces cerevisiae and Schizosaccharomyces pombe has greatly contributed to the understanding of cohesin composition and functions. In the last few years, much progress has been made in elucidating the role of cohesin in chromosome organization and compaction. Here, we discuss the different functions of cohesin to ensure faithful chromosome segregation and genome stability during the mitotic cell division in yeast. We describe what is known about its composition and how DNA replication is coupled with SCC establishment. We also discuss current models for the role of cohesin in chromatin loop extrusion and delineate unanswered questions about the activity of this important, conserved complex.
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Affiliation(s)
- Karan Choudhary
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Martin Kupiec
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv 69978, Israel
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15
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Levinsky AJ, McEdwards G, Sethna N, Currie MA. Targets of histone H3 lysine 9 methyltransferases. Front Cell Dev Biol 2022; 10:1026406. [PMID: 36568972 PMCID: PMC9768651 DOI: 10.3389/fcell.2022.1026406] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/05/2022] [Indexed: 12/12/2022] Open
Abstract
Histone H3 lysine 9 di- and trimethylation are well-established marks of constitutively silenced heterochromatin domains found at repetitive DNA elements including pericentromeres, telomeres, and transposons. Loss of heterochromatin at these sites causes genomic instability in the form of aberrant DNA repair, chromosome segregation defects, replication stress, and transposition. H3K9 di- and trimethylation also regulate cell type-specific gene expression during development and form a barrier to cellular reprogramming. However, the role of H3K9 methyltransferases extends beyond histone methylation. There is a growing list of non-histone targets of H3K9 methyltransferases including transcription factors, steroid hormone receptors, histone modifying enzymes, and other chromatin regulatory proteins. Additionally, two classes of H3K9 methyltransferases modulate their own function through automethylation. Here we summarize the structure and function of mammalian H3K9 methyltransferases, their roles in genome regulation and constitutive heterochromatin, as well as the current repertoire of non-histone methylation targets including cases of automethylation.
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Affiliation(s)
- Aidan J. Levinsky
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Gregor McEdwards
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Nasha Sethna
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Mark A. Currie
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada,*Correspondence: Mark A. Currie,
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16
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Kuenzel NA, Alcázar-Román AR, Saiardi A, Bartsch SM, Daunaraviciute S, Fiedler D, Fleig U. Inositol Pyrophosphate-Controlled Kinetochore Architecture and Mitotic Entry in S. pombe. J Fungi (Basel) 2022; 8:933. [PMID: 36135658 PMCID: PMC9506091 DOI: 10.3390/jof8090933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Inositol pyrophosphates (IPPs) comprise a specific class of signaling molecules that regulate central biological processes in eukaryotes. The conserved Vip1/PPIP5K family controls intracellular IP8 levels, the highest phosphorylated form of IPPs present in yeasts, as it has both inositol kinase and pyrophosphatase activities. Previous studies have shown that the fission yeast S. pombe Vip1/PPIP5K family member Asp1 impacts chromosome transmission fidelity via the modulation of spindle function. We now demonstrate that an IP8 analogue is targeted by endogenous Asp1 and that cellular IP8 is subject to cell cycle control. Mitotic entry requires Asp1 kinase function and IP8 levels are increased at the G2/M transition. In addition, the kinetochore, the conductor of chromosome segregation that is assembled on chromosomes is modulated by IP8. Members of the yeast CCAN kinetochore-subcomplex such as Mal2/CENP-O localize to the kinetochore depending on the intracellular IP8-level: higher than wild-type IP8 levels reduce Mal2 kinetochore targeting, while a reduction in IP8 has the opposite effect. As our perturbations of the inositol polyphosphate and IPP pathways demonstrate that kinetochore architecture depends solely on IP8 and not on other IPPs, we conclude that chromosome transmission fidelity is controlled by IP8 via an interplay between entry into mitosis, kinetochore architecture, and spindle dynamics.
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Affiliation(s)
- Natascha Andrea Kuenzel
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Abel R. Alcázar-Román
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, Gower St., London WC1E 6BT, UK
| | - Simon M. Bartsch
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Sarune Daunaraviciute
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Dorothea Fiedler
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Ursula Fleig
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
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17
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Wu W, McHugh T, Kelly DA, Pidoux AL, Allshire RC. Establishment of centromere identity is dependent on nuclear spatial organization. Curr Biol 2022; 32:3121-3136.e6. [PMID: 35830853 PMCID: PMC9616734 DOI: 10.1016/j.cub.2022.06.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 04/24/2022] [Accepted: 06/15/2022] [Indexed: 11/15/2022]
Abstract
The establishment of centromere-specific CENP-A chromatin is influenced by epigenetic and genetic processes. Central domain sequences from fission yeast centromeres are preferred substrates for CENP-ACnp1 incorporation, but their use is context dependent, requiring adjacent heterochromatin. CENP-ACnp1 overexpression bypasses heterochromatin dependency, suggesting that heterochromatin ensures exposure to conditions or locations permissive for CENP-ACnp1 assembly. Centromeres cluster around spindle-pole bodies (SPBs). We show that heterochromatin-bearing minichromosomes localize close to SPBs, consistent with this location promoting CENP-ACnp1 incorporation. We demonstrate that heterochromatin-independent de novo CENP-ACnp1 chromatin assembly occurs when central domain DNA is placed near, but not far from, endogenous centromeres or neocentromeres. Moreover, direct tethering of central domain DNA at SPBs permits CENP-ACnp1 assembly, suggesting that the nuclear compartment surrounding SPBs is permissive for CENP-ACnp1 incorporation because target sequences are exposed to high levels of CENP-ACnp1 and associated assembly factors. Thus, nuclear spatial organization is a key epigenetic factor that influences centromere identity.
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Affiliation(s)
- Weifang Wu
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Toni McHugh
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - David A Kelly
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Alison L Pidoux
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK.
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18
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Gavade JN, Black BE. Chromosomes: A nuclear neighborhood conducive to centromere formation. Curr Biol 2022; 32:R776-R778. [PMID: 35882197 DOI: 10.1016/j.cub.2022.06.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Centromere identity is specified by nucleosomes containing the histone variant CENP-A. A new study reveals that subnuclear location dictates the efficiency with which a new centromere forms.
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Affiliation(s)
- Janardan N Gavade
- Department of Biochemistry and Biophysics, Penn Center for Genome Integrity, Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ben E Black
- Department of Biochemistry and Biophysics, Penn Center for Genome Integrity, Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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19
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Esposito E, Weidemann DE, Rogers JM, Morton CM, Baybay EK, Chen J, Hauf S. Mitotic checkpoint gene expression is tuned by codon usage bias. EMBO J 2022; 41:e107896. [PMID: 35811551 PMCID: PMC9340482 DOI: 10.15252/embj.2021107896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/30/2022] [Accepted: 06/06/2022] [Indexed: 11/09/2022] Open
Abstract
The mitotic checkpoint (also called spindle assembly checkpoint, SAC) is a signaling pathway that safeguards proper chromosome segregation. Correct functioning of the SAC depends on adequate protein concentrations and appropriate stoichiometries between SAC proteins. Yet very little is known about the regulation of SAC gene expression. Here, we show in the fission yeast Schizosaccharomyces pombe that a combination of short mRNA half-lives and long protein half-lives supports stable SAC protein levels. For the SAC genes mad2+ and mad3+ , their short mRNA half-lives are caused, in part, by a high frequency of nonoptimal codons. In contrast, mad1+ mRNA has a short half-life despite a higher frequency of optimal codons, and despite the lack of known RNA-destabilizing motifs. Hence, different SAC genes employ different strategies of expression. We further show that Mad1 homodimers form co-translationally, which may necessitate a certain codon usage pattern. Taken together, we propose that the codon usage of SAC genes is fine-tuned to ensure proper SAC function. Our work shines light on gene expression features that promote spindle assembly checkpoint function and suggests that synonymous mutations may weaken the checkpoint.
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Affiliation(s)
- Eric Esposito
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Douglas E Weidemann
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Jessie M Rogers
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Claire M Morton
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Erod Keaton Baybay
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Jing Chen
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
| | - Silke Hauf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, USA
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20
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Varberg JM, Unruh JR, Bestul AJ, Khan AA, Jaspersen SL. Quantitative analysis of nuclear pore complex organization in Schizosaccharomyces pombe. Life Sci Alliance 2022; 5:5/7/e202201423. [PMID: 35354597 PMCID: PMC8967992 DOI: 10.26508/lsa.202201423] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 01/06/2023] Open
Abstract
Characterization of nuclear pores in Schizosaccharomyces pombe identifies regions of heterogeneous NPC density and composition and shows that NPCs are excluded near the spindle pole body by Lem2-mediated centromere tethering. The number, distribution, and composition of nuclear pore complexes (NPCs) in the nuclear envelope varies between cell types and changes during cellular differentiation and in disease. To understand how NPC density and organization are controlled, we analyzed the NPC number and distribution in the fission yeast Schizosaccharomyces pombe using structured illumination microscopy. The small size of yeast nuclei, genetic features of fungi, and our robust image analysis pipeline allowed us to study NPCs in intact nuclei under multiple conditions. Our data revealed that NPC density is maintained across a wide range of nuclear sizes. Regions of reduced NPC density are observed over the nucleolus and surrounding the spindle pole body (SPB). Lem2-mediated tethering of the centromeres to the SPB is required to maintain NPC exclusion near SPBs. These findings provide a quantitative understanding of NPC number and distribution in S. pombe and show that interactions between the centromere and the nuclear envelope influences local NPC distribution.
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Affiliation(s)
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Andrew J Bestul
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Azqa A Khan
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO, USA .,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
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21
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Jiménez-Martín A, Pineda-Santaella A, Pinto-Cruz J, León-Periñán D, García-Sánchez S, Delgado-Gestoso D, Marín-Toral L, Fernández-Álvarez A. The Rabl chromosome configuration masks a kinetochore reassembly mechanism in yeast mitosis. Mol Biol Cell 2022; 33:br8. [PMID: 35274979 PMCID: PMC9282007 DOI: 10.1091/mbc.e20-09-0600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During cell cycle progression in metazoans, the kinetochore is assembled at mitotic onset and disassembled during mitotic exit. Once assembled, the kinetochore complex attached to centromeres interacts directly with the spindle microtubules, the vehicle of chromosome segregation. This reassembly program is assumed to be absent in budding and fission yeast, because most kinetochore proteins are stably maintained at the centromeres throughout the entire cell cycle. Here, we show that the reassembly program of the outer kinetochore at mitotic onset is unexpectedly conserved in the fission yeast Schizosaccharomyces pombe. We identified this behavior by removing the Rabl chromosome configuration, in which centromeres are permanently associated with the nuclear envelope beneath the spindle pole body during interphase. In addition to having evolutionary implications for kinetochore reassembly, our results aid the understanding of the molecular processes responsible for kinetochore disassembly and assembly during mitotic entry.
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Affiliation(s)
- Alberto Jiménez-Martín
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain).,Instituto de Biología Funcional y Genómica (IBFG) (Consejo Superior de Investigaciones Científicas and Universidad de Salamanca). Calle Zacarías González 2, 37007 Salamanca (Spain)
| | - Alberto Pineda-Santaella
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain)
| | - Jesús Pinto-Cruz
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain)
| | - Daniel León-Periñán
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain)
| | - Sabas García-Sánchez
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain)
| | - David Delgado-Gestoso
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain)
| | - Laura Marín-Toral
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain)
| | - Alfonso Fernández-Álvarez
- Andalusian Center for Developmental Biology (CABD) (Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide and Junta de Andalucía). Ctra. Utrera km. 1, 41013 Seville (Spain).,Instituto de Biología Funcional y Genómica (IBFG) (Consejo Superior de Investigaciones Científicas and Universidad de Salamanca). Calle Zacarías González 2, 37007 Salamanca (Spain)
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22
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Brändle F, Frühbauer B, Jagannathan M. Principles and functions of pericentromeric satellite DNA clustering into chromocenters. Semin Cell Dev Biol 2022; 128:26-39. [PMID: 35144860 DOI: 10.1016/j.semcdb.2022.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/03/2022] [Accepted: 02/03/2022] [Indexed: 12/29/2022]
Abstract
Simple non-coding tandem repeats known as satellite DNA are observed widely across eukaryotes. These repeats occupy vast regions at the centromere and pericentromere of chromosomes but their contribution to cellular function has remained incompletely understood. Here, we review the literature on pericentromeric satellite DNA and discuss its organization and functions across eukaryotic species. We specifically focus on chromocenters, DNA-dense nuclear foci that contain clustered pericentromeric satellite DNA repeats from multiple chromosomes. We first discuss chromocenter formation and the roles that epigenetic modifications, satellite DNA transcripts and sequence-specific satellite DNA-binding play in this process. We then review the newly emerging functions of chromocenters in genome encapsulation, the maintenance of cell fate and speciation. We specifically highlight how the rapid divergence of satellite DNA repeats impacts reproductive isolation between closely related species. Together, we underline the importance of this so-called 'junk DNA' in fundamental biological processes.
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Affiliation(s)
- Franziska Brändle
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland
| | - Benjamin Frühbauer
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland
| | - Madhav Jagannathan
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland.
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23
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3D Genome Organization: Causes and Consequences for DNA Damage and Repair. Genes (Basel) 2021; 13:genes13010007. [PMID: 35052348 PMCID: PMC8775012 DOI: 10.3390/genes13010007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 01/02/2023] Open
Abstract
The inability to repair damaged DNA severely compromises the integrity of any organism. In eukaryotes, the DNA damage response (DDR) operates within chromatin, a tightly organized DNA–histone complex in a non-random manner within the nucleus. Chromatin thus orchestrates various cellular processes, including repair. Here, we examine the chromatin landscape before, during, and after the DNA damage, focusing on double strand breaks (DSBs). We study how chromatin is modified during the repair process, not only around the damaged region (in cis), but also genome-wide (in trans). Recent evidence has highlighted a complex landscape in which different chromatin parameters (stiffness, compaction, loops) are transiently modified, defining “codes” for each specific stage of the DDR. We illustrate a novel aspect of DDR where chromatin modifications contribute to the movement of DSB-damaged chromatin, as well as undamaged chromatin, ensuring the mobilization of DSBs, their clustering, and their repair processes.
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24
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Bestul AJ, Yu Z, Unruh JR, Jaspersen SL. Redistribution of centrosomal proteins by centromeres and Polo kinase controls partial nuclear envelope breakdown in fission yeast. Mol Biol Cell 2021; 32:1487-1500. [PMID: 34133218 PMCID: PMC8351742 DOI: 10.1091/mbc.e21-05-0239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Proper mitotic progression in Schizosaccharomyces pombe requires partial nuclear envelope breakdown (NEBD) and insertion of the spindle pole body (SPB—yeast centrosome) to build the mitotic spindle. Linkage of the centromere to the SPB is vital to this process, but why that linkage is important is not well understood. Utilizing high-resolution structured illumination microscopy, we show that the conserved Sad1-UNC-84 homology-domain protein Sad1 and other SPB proteins redistribute during mitosis to form a ring complex around SPBs, which is a precursor for localized NEBD and spindle formation. Although the Polo kinase Plo1 is not necessary for Sad1 redistribution, it localizes to the SPB region connected to the centromere, and its activity is vital for redistribution of other SPB ring proteins and for complete NEBD at the SPB to allow for SPB insertion. Our results lead to a model in which centromere linkage to the SPB drives redistribution of Sad1 and Plo1 activation that in turn facilitate partial NEBD and spindle formation through building of a SPB ring structure.
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Affiliation(s)
- Andrew J Bestul
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Zulin Yu
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO 64110
| | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO 64110.,Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160
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25
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Todd S, Todd P, McGowan SJ, Hughes JR, Kakui Y, Leymarie FF, Latham W, Taylor S. CSynth: an interactive modelling and visualization tool for 3D chromatin structure. Bioinformatics 2021; 37:951-955. [PMID: 32866221 PMCID: PMC8128456 DOI: 10.1093/bioinformatics/btaa757] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 01/22/2023] Open
Abstract
MOTIVATION The 3D structure of chromatin in the nucleus is important for gene expression and regulation. Chromosome conformation capture techniques, such as Hi-C, generate large amounts of data showing interaction points on the genome but these are hard to interpret using standard tools. RESULTS We have developed CSynth, an interactive 3D genome browser and real-time chromatin restraint-based modeller to visualize models of any chromosome conformation capture (3C) data. Unlike other modelling systems, CSynth allows dynamic interaction with the modelling parameters to allow experimentation and effects on the model. It also allows comparison of models generated from data in different tissues/cell states and the results of third-party 3D modelling outputs. In addition, we include an option to view and manipulate these complicated structures using Virtual Reality (VR) so scientists can immerse themselves in the models for further understanding. This VR component has also proven to be a valuable teaching and a public engagement tool. AVAILABILITYAND IMPLEMENTATION CSynth is web based and available to use at csynth.org. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Stephen Todd
- Department of Computing, Goldsmiths, University of London, London, UK
- London Geometry, Ltd., London, UK
| | | | - Simon J McGowan
- Analysis, Visualization and Informatics, MRC Weatherall Institute of Molecular Medicine, Oxford, UK
| | - James R Hughes
- Genome Biology Group, MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, Oxford, UK
| | - Yasutaka Kakui
- The Francis Crick Institute, Chromosome Segregation Laboratory, London, UK
| | - Frederic Fol Leymarie
- Department of Computing, Goldsmiths, University of London, London, UK
- London Geometry, Ltd., London, UK
| | - William Latham
- Department of Computing, Goldsmiths, University of London, London, UK
- London Geometry, Ltd., London, UK
| | - Stephen Taylor
- Analysis, Visualization and Informatics, MRC Weatherall Institute of Molecular Medicine, Oxford, UK
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26
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Kim KD. Potential roles of condensin in genome organization and beyond in fission yeast. J Microbiol 2021; 59:449-459. [PMID: 33877578 DOI: 10.1007/s12275-021-1039-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 11/24/2022]
Abstract
The genome is highly organized hierarchically by the function of structural maintenance of chromosomes (SMC) complex proteins such as condensin and cohesin from bacteria to humans. Although the roles of SMC complex proteins have been well characterized, their specialized roles in nuclear processes remain unclear. Condensin and cohesin have distinct binding sites and mediate long-range and short-range genomic associations, respectively, to form cell cycle-specific genome organization. Condensin can be recruited to highly expressed genes as well as dispersed repeat genetic elements, such as Pol III-transcribed genes, LTR retrotransposon, and rDNA repeat. In particular, mitotic transcription factors Ace2 and Ams2 recruit condensin to their target genes, forming centromeric clustering during mitosis. Condensin is potentially involved in various chromosomal processes such as the mobility of chromosomes, chromosome territories, DNA reannealing, and transcription factories. The current knowledge of condensin in fission yeast summarized in this review can help us understand how condensin mediates genome organization and participates in chromosomal processes in other organisms.
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Affiliation(s)
- Kyoung-Dong Kim
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 17546, Republic of Korea.
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27
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Sato M, Kakui Y, Toya M. Tell the Difference Between Mitosis and Meiosis: Interplay Between Chromosomes, Cytoskeleton, and Cell Cycle Regulation. Front Cell Dev Biol 2021; 9:660322. [PMID: 33898463 PMCID: PMC8060462 DOI: 10.3389/fcell.2021.660322] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/02/2021] [Indexed: 12/04/2022] Open
Abstract
Meiosis is a specialized style of cell division conserved in eukaryotes, particularly designed for the production of gametes. A huge number of studies to date have demonstrated how chromosomes behave and how meiotic events are controlled. Yeast substantially contributed to the understanding of the molecular mechanisms of meiosis in the past decades. Recently, evidence began to accumulate to draw a perspective landscape showing that chromosomes and microtubules are mutually influenced: microtubules regulate chromosomes, whereas chromosomes also regulate microtubule behaviors. Here we focus on lessons from recent advancement in genetical and cytological studies of the fission yeast Schizosaccharomyces pombe, revealing how chromosomes, cytoskeleton, and cell cycle progression are organized and particularly how these are differentiated in mitosis and meiosis. These studies illuminate that meiosis is strategically designed to fulfill two missions: faithful segregation of genetic materials and production of genetic diversity in descendants through elaboration by meiosis-specific factors in collaboration with general factors.
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Affiliation(s)
- Masamitsu Sato
- Laboratory of Cytoskeletal Logistics, Center for Advanced Biomedical Sciences (TWIns), Waseda University, Tokyo, Japan.,Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.,Institute for Medical-Oriented Structural Biology, Waseda University, Tokyo, Japan
| | - Yasutaka Kakui
- Laboratory of Cytoskeletal Logistics, Center for Advanced Biomedical Sciences (TWIns), Waseda University, Tokyo, Japan.,Waseda Institute for Advanced Study, Waseda University, Tokyo, Japan
| | - Mika Toya
- Laboratory of Cytoskeletal Logistics, Center for Advanced Biomedical Sciences (TWIns), Waseda University, Tokyo, Japan.,Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.,Major in Bioscience, Global Center for Science and Engineering, Faculty of Science and Engineering, Waseda University, Tokyo, Japan
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28
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Kundu S, Ray MD, Sharma A. Interplay between genome organization and epigenomic alterations of pericentromeric DNA in cancer. J Genet Genomics 2021; 48:184-197. [PMID: 33840602 DOI: 10.1016/j.jgg.2021.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 02/07/2021] [Accepted: 02/20/2021] [Indexed: 12/16/2022]
Abstract
In eukaryotic genome biology, the genomic organization inside the three-dimensional (3D) nucleus is highly complex, and whether this organization governs gene expression is poorly understood. Nuclear lamina (NL) is a filamentous meshwork of proteins present at the lining of inner nuclear membrane that serves as an anchoring platform for genome organization. Large chromatin domains termed as lamina-associated domains (LADs), play a major role in silencing genes at the nuclear periphery. The interaction of the NL and genome is dynamic and stochastic. Furthermore, many genes change their positions during developmental processes or under disease conditions such as cancer, to activate certain sorts of genes and/or silence others. Pericentromeric heterochromatin (PCH) is mostly in the silenced region within the genome, which localizes at the nuclear periphery. Studies show that several genes located at the PCH are aberrantly expressed in cancer. The interesting question is that despite being localized in the pericentromeric region, how these genes still manage to overcome pericentromeric repression. Although epigenetic mechanisms control the expression of the pericentromeric region, recent studies about genome organization and genome-nuclear lamina interaction have shed light on a new aspect of pericentromeric gene regulation through a complex and coordinated interplay between epigenomic remodeling and genomic organization in cancer.
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Affiliation(s)
- Subhadip Kundu
- Laboratory of Chromatin and Cancer Epigenetics, Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - M D Ray
- Department of Surgical Oncology, IRCH, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Ashok Sharma
- Laboratory of Chromatin and Cancer Epigenetics, Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
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29
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Singh P, Halova L, Hagan IM. Highly Synchronous Mitotic Progression in Schizosaccharomyces pombe Upon Relief of Transient Cdc2-asM17 Inhibition. Methods Mol Biol 2021; 2329:123-142. [PMID: 34085220 DOI: 10.1007/978-1-0716-1538-6_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
Synchronized progression of a cell population through the cell division cycle supports the biochemical and functional dissection of cell cycle controls and execution. The concerted behaviour of the population reflects the attributes of each cell within that population. The reversible imposition of a block to cell cycle progression at the G2-M boundary through transient inactivation of the Cdk1-Cyclin B activating phosphatase, Cdc25, with the temperature sensitive cdc25-22 mutant, has been widely used to study fission yeast mitosis and DNA replication. However, the biology of the compromised Cdc25-22 phosphatase generates significant division abnormalities upon release from mitotic arrest. We show how reversible inhibition of Cdc2-asM17, with the ATP analog 3-BrB-PP1, generates higher levels of synchrony with timing and morphology much more reminiscent of a normal division. We also describe a version of the H1 kinase assay of Cdk1-Cyclin B activity that is widely used to monitor mitotic progression which does not require radiolabeled ATP.
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Affiliation(s)
- Pawan Singh
- Cell Division Group, CRUK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Lenka Halova
- Cell Division Group, CRUK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Iain Michael Hagan
- Cell Division Group, CRUK Manchester Institute, The University of Manchester, Alderley Park, UK.
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30
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Burla R, La Torre M, Maccaroni K, Verni F, Giunta S, Saggio I. Interplay of the nuclear envelope with chromatin in physiology and pathology. Nucleus 2020; 11:205-218. [PMID: 32835589 PMCID: PMC7529417 DOI: 10.1080/19491034.2020.1806661] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 12/21/2022] Open
Abstract
The nuclear envelope compartmentalizes chromatin in eukaryotic cells. The main nuclear envelope components are lamins that associate with a panoply of factors, including the LEM domain proteins. The nuclear envelope of mammalian cells opens up during cell division. It is reassembled and associated with chromatin at the end of mitosis when telomeres tether to the nuclear periphery. Lamins, LEM domain proteins, and DNA binding factors, as BAF, contribute to the reorganization of chromatin. In this context, an emerging role is that of the ESCRT complex, a machinery operating in multiple membrane assembly pathways, including nuclear envelope reformation. Research in this area is unraveling how, mechanistically, ESCRTs link to nuclear envelope associated factors as LEM domain proteins. Importantly, ESCRTs work also during interphase for repairing nuclear envelope ruptures. Altogether the advances in this field are giving new clues for the interpretation of diseases implicating nuclear envelope fragility, as laminopathies and cancer. ABBREVIATIONS na, not analyzed; ko, knockout; kd, knockdown; NE, nuclear envelope; LEM, LAP2-emerin-MAN1 (LEM)-domain containing proteins; LINC, linker of nucleoskeleton and cytoskeleton complexes; Cyt, cytoplasm; Chr, chromatin; MB, midbody; End, endosomes; Tel, telomeres; INM, inner nuclear membrane; NP, nucleoplasm; NPC, Nuclear Pore Complex; ER, Endoplasmic Reticulum; SPB, spindle pole body.
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Affiliation(s)
- Romina Burla
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
- CNR Institute of Molecular Biology and Pathology, Italy
| | - Mattia La Torre
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Klizia Maccaroni
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Fiammetta Verni
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
| | - Simona Giunta
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
- Rockefeller University, New York, NY, USA
| | - Isabella Saggio
- Department of Biology and Biotechnology, Sapienza University of Rome, Rome, Italy
- CNR Institute of Molecular Biology and Pathology, Italy
- Institute of Structural Biology, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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31
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Cherezov RO, Vorontsova JE, Simonova OB. TBP-Related Factor 2 as a Trigger for Robertsonian Translocations and Speciation. Int J Mol Sci 2020; 21:E8871. [PMID: 33238614 PMCID: PMC7700478 DOI: 10.3390/ijms21228871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 11/16/2022] Open
Abstract
Robertsonian (centric-fusion) translocation is the form of chromosomal translocation in which two long arms of acrocentric chromosomes are fused to form one metacentric. These translocations reduce the number of chromosomes while preserving existing genes and are considered to contribute to speciation. We asked whether hypomorphic mutations in genes that disrupt the formation of pericentromeric regions could lead to centric fusion. TBP-related factor 2 (Trf2) encodes an alternative general transcription factor. A decrease of TRF2 expression disrupts the structure of the pericentromeric regions and prevents their association into chromocenter. We revealed several centric fusions in two lines of Drosophila melanogaster with weak Trf2 alleles in genetic experiments. We performed an RNAi-mediated knock-down of Trf2 in Drosophila and S2 cells and demonstrated that Trf2 upregulates expression of D1-one of the major genes responsible for chromocenter formation and nuclear integrity in Drosophila. Our data, for the first time, indicate that Trf2 may be involved in transcription program responsible for structuring of pericentromeric regions and may contribute to new karyotypes formation in particular by promoting centric fusion. Insight into the molecular mechanisms of Trf2 function and its new targets in different tissues will contribute to our understanding of its phenomenon.
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Affiliation(s)
| | | | - Olga B. Simonova
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Vavilova str. 26, 119991 Moscow, Russia; (R.O.C.); (J.E.V.)
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32
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Nuclear Envelope Proteins Modulating the Heterochromatin Formation and Functions in Fission Yeast. Cells 2020; 9:cells9081908. [PMID: 32824370 PMCID: PMC7464478 DOI: 10.3390/cells9081908] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/14/2020] [Accepted: 08/15/2020] [Indexed: 12/16/2022] Open
Abstract
The nuclear envelope (NE) consists of the inner and outer nuclear membranes (INM and ONM), and the nuclear pore complex (NPC), which penetrates the double membrane. ONM continues with the endoplasmic reticulum (ER). INM and NPC can interact with chromatin to regulate the genetic activities of the chromosome. Studies in the fission yeast Schizosaccharomyces pombe have contributed to understanding the molecular mechanisms underlying heterochromatin formation by the RNAi-mediated and histone deacetylase machineries. Recent studies have demonstrated that NE proteins modulate heterochromatin formation and functions through interactions with heterochromatic regions, including the pericentromeric and the sub-telomeric regions. In this review, we first introduce the molecular mechanisms underlying the heterochromatin formation and functions in fission yeast, and then summarize the NE proteins that play a role in anchoring heterochromatic regions and in modulating heterochromatin formation and functions, highlighting roles for a conserved INM protein, Lem2.
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33
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Francia ME, Bhavsar S, Ting LM, Croken MM, Kim K, Dubremetz JF, Striepen B. A Homolog of Structural Maintenance of Chromosome 1 Is a Persistent Centromeric Protein Which Associates With Nuclear Pore Components in Toxoplasma gondii. Front Cell Infect Microbiol 2020; 10:295. [PMID: 32714878 PMCID: PMC7343853 DOI: 10.3389/fcimb.2020.00295] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 05/19/2020] [Indexed: 01/02/2023] Open
Abstract
Apicomplexa are obligate intracellular parasites which cause various animal and human diseases including malaria, toxoplasmosis, and cryptosporidiosis. They proliferate by a unique mechanism that combines physically separated semi-closed mitosis of the nucleus and assembly of daughter cells by internal budding. Mitosis occurs in the presence of a nuclear envelope and with little appreciable chromatin condensation. A long standing question in the field has been how parasites keep track of their uncondensed chromatin chromosomes throughout their development, and hence secure proper chromosome segregation during division. Past work demonstrated that the centromeres, the region of kinetochore assembly at chromosomes, of Toxoplasma gondii remain clustered at a defined region of the nuclear periphery proximal to the main microtubule organizing center of the cell, the centrosome. We have proposed that this mechanism is likely involved in the process. Here we set out to identify underlying molecular players involved in centromere clustering. Through pharmacological treatment and structural analysis we show that centromere clustering is not mediated by persistent microtubules of the mitotic spindle. We identify the chromatin binding factor a homolog of structural maintenance of chromosomes 1 (SMC1). Additionally, we show that both TgSMC1, and a centromeric histone, interact with TgExportin1, a predicted soluble component of the nuclear pore complex. Our results suggest that the nuclear envelope, and in particular the nuclear pore complex may play a role in positioning centromeres in T. gondii.
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Affiliation(s)
- Maria E Francia
- Department of Cellular Biology, University of Georgia, Athens, GA, United States
| | - Sheila Bhavsar
- Department of Cellular Biology, University of Georgia, Athens, GA, United States
| | - Li-Min Ting
- Morsani College of Medicine, University of South Florida Health, Tampa, FL, United States
| | - Matthew M Croken
- Pathology, Molecular and Cell Based Medicine, Mount Sinai Medical Center, New York, NY, United States
| | - Kami Kim
- Morsani College of Medicine, University of South Florida Health, Tampa, FL, United States
| | | | - Boris Striepen
- Department of Cellular Biology, University of Georgia, Athens, GA, United States.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
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34
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Oko Y, Ito N, Sakamoto T. The mechanisms and significance of the positional control of centromeres and telomeres in plants. JOURNAL OF PLANT RESEARCH 2020; 133:471-478. [PMID: 32410007 DOI: 10.1007/s10265-020-01202-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/04/2020] [Indexed: 05/23/2023]
Abstract
The centromere and telomere are universal heterochromatic domains; however, the proper positioning of those domains in nuclear space during the mitotic interphase differs among eukaryotes. Consequently, the question arises how and why this difference occurs. Studies over the past 2 decades have identified several nuclear membrane proteins, nucleolar proteins, and the structural maintenance of a chromosome complex as factors involved in the positional control of centromeres and/or telomeres during the mitotic interphase in yeasts, animals, and plants. In this review, with a primary focus on plants, the roles of those factors are summarized, and the biological significance of proper centromere and telomere positionings during the mitotic interphase is discussed in an effort to provide guidance for this question.
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Affiliation(s)
- Yuka Oko
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Chiba, Japan
| | - Nanami Ito
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Chiba, Japan
| | - Takuya Sakamoto
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Chiba, Japan.
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35
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Loncar A, Rincon SA, Lera Ramirez M, Paoletti A, Tran PT. Kinesin-14 family proteins and microtubule dynamics define S. pombe mitotic and meiotic spindle assembly, and elongation. J Cell Sci 2020; 133:jcs240234. [PMID: 32327557 PMCID: PMC7295595 DOI: 10.1242/jcs.240234] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 04/06/2020] [Indexed: 12/18/2022] Open
Abstract
To segregate the chromosomes faithfully during cell division, cells assemble a spindle that captures the kinetochores and pulls them towards opposite poles. Proper spindle function requires correct interplay between microtubule motors and non-motor proteins. Defects in spindle assembly or changes in spindle dynamics are associated with diseases, such as cancer or developmental disorders. Here, we compared mitotic and meiotic spindles in fission yeast. We show that, even though mitotic and meiotic spindles underwent the typical three phases of spindle elongation, they have distinct features. We found that the relative concentration of the kinesin-14 family protein Pkl1 is decreased in meiosis I compared to mitosis, while the concentration of the kinesin-5 family protein Cut7 remains constant. We identified the second kinesin-14 family protein Klp2 and microtubule dynamics as factors necessary for proper meiotic spindle assembly. This work defines the differences between mitotic and meiotic spindles in fission yeast Schizosaccharomyces pombe, and provides prospect for future comparative studies.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Ana Loncar
- Institute Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France
| | - Sergio A Rincon
- Instituto de Biología Funcional y Genómica/Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca 37007, Spain
| | - Manuel Lera Ramirez
- Institute Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France
| | - Anne Paoletti
- Institute Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France
| | - Phong T Tran
- Institute Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France
- University of Pennsylvania, Department of Cell and Developmental Biology, Philadelphia, PA 19104, USA
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36
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Maestroni L, Reyes C, Vaurs M, Gachet Y, Tournier S, Géli V, Coulon S. Nuclear envelope attachment of telomeres limits TERRA and telomeric rearrangements in quiescent fission yeast cells. Nucleic Acids Res 2020; 48:3029-3041. [PMID: 31980821 PMCID: PMC7102995 DOI: 10.1093/nar/gkaa043] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 11/12/2022] Open
Abstract
Telomere anchoring to nuclear envelope (NE) is a key feature of nuclear genome architecture. Peripheral localization of telomeres is important for chromatin silencing, telomere replication and for the control of inappropriate recombination. Here, we report that fission yeast quiescent cells harbor predominantly a single telomeric cluster anchored to the NE. Telomere cluster association to the NE relies on Rap1-Bqt4 interaction, which is impacted by the length of telomeric sequences. In quiescent cells, reducing telomere length or deleting bqt4, both result in an increase in transcription of the telomeric repeat-containing RNA (TERRA). In the absence of Bqt4, telomere shortening leads to deep increase in TERRA level and the concomitant formation of subtelomeric rearrangements (STEEx) that accumulate massively in quiescent cells. Taken together, our data demonstrate that Rap1-Bqt4-dependent telomere association to NE preserves telomere integrity in post-mitotic cells, preventing telomeric transcription and recombination. This defines the nuclear periphery as an area where recombination is restricted, creating a safe zone for telomeres of post-mitotic cells.
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Affiliation(s)
- Laetitia Maestroni
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
| | - Céline Reyes
- LBCMCP, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Mélina Vaurs
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
| | - Yannick Gachet
- LBCMCP, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Sylvie Tournier
- LBCMCP, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Vincent Géli
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
| | - Stéphane Coulon
- CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, Marseille, France. Equipe labellisée Ligue contre le Cancer, France
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37
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Hocher A, Taddei A. Subtelomeres as Specialized Chromatin Domains. Bioessays 2020; 42:e1900205. [PMID: 32181520 DOI: 10.1002/bies.201900205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/19/2020] [Indexed: 12/26/2022]
Abstract
Specificities associated with chromosomal linearity are not restricted to telomeres. Here, recent results obtained on fission and budding yeast are summarized and an attempt is made to define subtelomeres using chromatin features extending beyond the heterochromatin emanating from telomeres. Subtelomeres, the chromosome domains adjacent to telomeres, differ from the rest of the genome by their gene content, rapid evolution, and chromatin features that together contribute to organism adaptation. However, current definitions of subtelomeres are generally based on synteny and are largely gene-centered. Taking into consideration both the peculiar gene content and dynamics as well as the chromatin properties of those domains, it is discussed how chromatin features can contribute to subtelomeric properties and functions, and play a pivotal role in the emergence of subtelomeres.
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Affiliation(s)
- Antoine Hocher
- MRC London Institute of Medical Sciences (LMS), Du Cane Road, London, W12 0NN, UK.,Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Angela Taddei
- Institut Curie, PSL Research University, CNRS, UMR3664, Paris, F-75005, France.,Sorbonne Université, UPMC University Paris 06, CNRS, UMR3664, Paris, F-75005, France
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38
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Gallardo P, Barrales RR, Daga RR, Salas-Pino S. Nuclear Mechanics in the Fission Yeast. Cells 2019; 8:cells8101285. [PMID: 31635174 PMCID: PMC6829894 DOI: 10.3390/cells8101285] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/14/2019] [Accepted: 10/17/2019] [Indexed: 12/13/2022] Open
Abstract
In eukaryotic cells, the organization of the genome within the nucleus requires the nuclear envelope (NE) and its associated proteins. The nucleus is subjected to mechanical forces produced by the cytoskeleton. The physical properties of the NE and the linkage of chromatin in compacted conformation at sites of cytoskeleton contacts seem to be key for withstanding nuclear mechanical stress. Mechanical perturbations of the nucleus normally occur during nuclear positioning and migration. In addition, cell contraction or expansion occurring for instance during cell migration or upon changes in osmotic conditions also result innuclear mechanical stress. Recent studies in Schizosaccharomyces pombe (fission yeast) have revealed unexpected functions of cytoplasmic microtubules in nuclear architecture and chromosome behavior, and have pointed to NE-chromatin tethers as protective elements during nuclear mechanics. Here, we review and discuss how fission yeast cells can be used to understand principles underlying the dynamic interplay between genome organization and function and the effect of forces applied to the nucleus by the microtubule cytoskeleton.
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Affiliation(s)
- Paola Gallardo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
| | - Ramón R Barrales
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
| | - Rafael R Daga
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
| | - Silvia Salas-Pino
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Junta de Andalucia, 41010 Seville, Spain.
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39
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Shirasugi Y, Sato M. Kinetochore-mediated outward force promotes spindle pole separation in fission yeast. Mol Biol Cell 2019; 30:2802-2813. [PMID: 31532702 PMCID: PMC6789161 DOI: 10.1091/mbc.e19-07-0366] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bipolar spindles are organized by motor proteins that generate microtubule-dependent forces to separate the two spindle poles. The fission yeast Cut7 (kinesin-5) is a plus-end-directed motor that generates the outward force to separate the two spindle poles, whereas the minus-end-directed motor Pkl1 (kinesin-14) generates the inward force. Balanced forces by these antagonizing kinesins are essential for bipolar spindle organization in mitosis. Here, we demonstrate that chromosomes generate another outward force that contributes to the bipolar spindle assembly. First, it was noted that the cut7 pkl1 double knockout failed to separate spindle poles in meiosis I, although the mutant is known to succeed it in mitosis. It was assumed that this might be because meiotic kinetochores of bivalent chromosomes joined by cross-overs generate weaker tensions in meiosis I than the strong tensions in mitosis generated by tightly tethered sister kinetochores. In line with this idea, when meiotic mono-oriented kinetochores were artificially converted to a mitotic bioriented layout, the cut7 pkl1 mutant successfully separated spindle poles in meiosis I. Therefore, we propose that spindle pole separation is promoted by outward forces transmitted from kinetochores to spindle poles through microtubules.
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Affiliation(s)
- Yutaka Shirasugi
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience
| | - Masamitsu Sato
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience.,Institute for Medical--Oriented Structural Biology, Waseda Research Institute for Science and Engineering, School of Advanced Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan.,Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, School of Advanced Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
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40
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Salas-Pino S, Daga RR. Spatiotemporal control of spindle disassembly in fission yeast. Cell Mol Life Sci 2019; 76:3543-3551. [PMID: 31129857 PMCID: PMC11105212 DOI: 10.1007/s00018-019-03139-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/29/2019] [Accepted: 05/07/2019] [Indexed: 12/20/2022]
Abstract
Maintenance of genomic stability during cell division is one of the most important cellular tasks, and it critically depends on the faithful replication of the genetic material and its equal partitioning into daughter cells, gametes, or spores in the case of yeasts. Defective mitotic spindle assembly and disassembly both result in changes in cellular ploidy that ultimately impinge proliferation fitness and might increase tumor malignancy. Although a great progress has been made in understanding how spindles are assembled to orchestrate chromosome segregation, much less is known about how they are disassembled once completed their function. Here, we review two recently uncovered mechanisms of spindle disassembly that operate at different stages of the fission yeast life cycle.
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Affiliation(s)
- Silvia Salas-Pino
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucia, Carretera de Utrera, km1, 41013, Seville, Spain.
| | - Rafael R Daga
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucia, Carretera de Utrera, km1, 41013, Seville, Spain.
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41
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Abstract
Magnaporthe oryzae is an important fungal pathogen that causes a loss of 10% to 30% of the annual rice crop due to the devastating blast disease. In most organisms, kinetochores are clustered together or arranged at the metaphase plate to facilitate synchronized anaphase separation of sister chromatids in mitosis. In this study, we showed that the initially clustered kinetochores separate and position randomly prior to anaphase in M. oryzae. Centromeres in M. oryzae occupy large genomic regions and form on AT-rich DNA without any common sequence motifs. Overall, this study identified atypical kinetochore dynamics and mapped functional centromeres in M. oryzae to define the roles of centromeric and pericentric boundaries in kinetochore assembly on epigenetically specified centromere loci. This study should pave the way for further understanding of the contribution of heterochromatin in genome stability and virulence of the blast fungus and its related species of high economic importance. Precise kinetochore-microtubule interactions ensure faithful chromosome segregation in eukaryotes. Centromeres, identified as scaffolding sites for kinetochore assembly, are among the most rapidly evolving chromosomal loci in terms of the DNA sequence and length and organization of intrinsic elements. Neither the centromere structure nor the kinetochore dynamics is well studied in plant-pathogenic fungi. Here, we sought to understand the process of chromosome segregation in the rice blast fungus Magnaporthe oryzae. High-resolution imaging of green fluorescent protein (GFP)-tagged inner kinetochore proteins CenpA and CenpC revealed unusual albeit transient declustering of centromeres just before anaphase separation of chromosomes in M. oryzae. Strikingly, the declustered centromeres positioned randomly at the spindle midzone without an apparent metaphase plate per se. Using CenpA chromatin immunoprecipitation followed by deep sequencing, all seven centromeres in M. oryzae were found to be regional, spanning 57-kb to 109-kb transcriptionally poor regions. Highly AT-rich and heavily methylated DNA sequences were the only common defining features of all the centromeres in rice blast. Lack of centromere-specific DNA sequence motifs or repetitive elements suggests an epigenetic specification of centromere function in M. oryzae. PacBio genome assemblies and synteny analyses facilitated comparison of the centromeric/pericentromeric regions in distinct isolates of rice blast and wheat blast and in Magnaporthiopsis poae. Overall, this study revealed unusual centromere dynamics and precisely identified the centromere loci in the top model fungal pathogens that belong to Magnaporthales and cause severe losses in the global production of food crops and turf grasses.
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42
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The Impact of Centromeres on Spatial Genome Architecture. Trends Genet 2019; 35:565-578. [PMID: 31200946 DOI: 10.1016/j.tig.2019.05.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/06/2019] [Accepted: 05/09/2019] [Indexed: 01/01/2023]
Abstract
The development of new technologies and experimental techniques is enabling researchers to see what was once unable to be seen. For example, the centromere was first seen as the mediator between spindle fiber and chromosome during mitosis and meiosis. Although this continues to be its most prominent role, we now know that the centromere functions beyond cellular division with important roles in genome organization and chromatin regulation. Here we aim to share the structures and functions of centromeres in various organisms beginning with the diversity of their DNA sequence anatomies. We zoom out to describe their position in the nucleus and ultimately detail the different ways they contribute to genome organization and regulation at the spatial level.
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43
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The Rabl configuration limits topological entanglement of chromosomes in budding yeast. Sci Rep 2019; 9:6795. [PMID: 31043625 PMCID: PMC6494875 DOI: 10.1038/s41598-019-42967-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 03/27/2019] [Indexed: 11/25/2022] Open
Abstract
The three dimensional organization of genomes remains mostly unknown due to their high degree of condensation. Biophysical studies predict that condensation promotes the topological entanglement of chromatin fibers and the inhibition of function. How organisms balance between functionally active genomes and a high degree of condensation remains to be determined. Here we hypothesize that the Rabl configuration, characterized by the attachment of centromeres and telomeres to the nuclear envelope, helps to reduce the topological entanglement of chromosomes. To test this hypothesis we developed a novel method to quantify chromosome entanglement complexity in 3D reconstructions obtained from Chromosome Conformation Capture (CCC) data. Applying this method to published data of the yeast genome, we show that computational models implementing the attachment of telomeres or centromeres alone are not sufficient to obtain the reduced entanglement complexity observed in 3D reconstructions. It is only when the centromeres and telomeres are attached to the nuclear envelope (i.e. the Rabl configuration) that the complexity of entanglement of the genome is comparable to that of the 3D reconstructions. We therefore suggest that the Rabl configuration is an essential player in the simplification of the entanglement of chromatin fibers.
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44
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Mittal P, Chavan A, Trakroo D, Shah S, Ghosh SK. Outer kinetochore protein Dam1 promotes centromere clustering in parallel with Slk19 in budding yeast. Chromosoma 2019; 128:133-148. [PMID: 30903360 DOI: 10.1007/s00412-019-00694-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 01/14/2019] [Accepted: 02/11/2019] [Indexed: 12/16/2022]
Abstract
A higher order organization of the centromeres in the form of clustering of these DNA loci has been observed in many organisms. While centromere clustering is biologically significant to achieve faithful chromosome segregation, the underlying molecular mechanism is yet to be fully understood. In budding yeast, a kinetochore-associated protein Slk19 is shown to have a role in clustering in association with the microtubules whereas removal of either Slk19 or microtubules alone does not have any effect on the centromere clustering. Furthermore, Slk19 is non-essential for growth and becomes cleaved during anaphase whereas clustering being an essential event occurs throughout the cell cycle. Hence, we searched for an additional factor involved in the clustering and since the integrity of the kinetochore complex is shown to be crucial for centromere clustering, we restricted our search within the complex. We observed that the outermost kinetochore protein Dam1 promotes centromere clustering through stabilization of the kinetochore integrity. While in the absence of Dam1 we failed to detect Slk19 at the centromere, on the other hand, we found almost no Dam1 at the centromere in the absence of Slk19 and microtubules suggesting interdependency between these two pathways. Strikingly, we observed that overexpression of Dam1 or Slk19 could restore the centromere clustering largely in the cells devoid of Slk19 and microtubules or Dam1, respectively. Thus, we propose that in budding yeast, centromere clustering is achieved at least by two parallel pathways, through Dam1 and another via Slk19, in concert with the microtubules suggesting that having a dual mechanism may be crucial for ensuring microtubule capture by the point centromeres where each attaches to only one microtubule.
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Affiliation(s)
- Priyanka Mittal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Ankita Chavan
- Molecular and Cell Biology Department, University of Connecticut, Storrs, CT, 06269, USA
| | - Deepika Trakroo
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Sanket Shah
- Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai, 410210, India
| | - Santanu K Ghosh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
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45
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Spindle pole body movement is affected by glucose and ammonium chloride in fission yeast. Biochem Biophys Res Commun 2019; 511:820-825. [PMID: 30846209 DOI: 10.1016/j.bbrc.2019.02.128] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 02/23/2019] [Indexed: 02/06/2023]
Abstract
The complexity of chromatin dynamics is orchestrated by several active processes. In fission yeast, the centromeres are clustered around the spindle pole body (SPB) and oscillate in a microtubule- and adenosine triphosphate (ATP)-dependent manner. However, whether and how SPB oscillation are affected by different environmental conditions remain poorly understood. In this study, we quantitated movements of the SPB component, which colocalizes with the centromere in fission yeast. We found that SPB movement was significantly reduced at low glucose concentrations. Movement of the SPB was also affected by the presence of ammonium chloride. Power spectral analysis revealed that periodic movement of the SPB is disrupted by low glucose concentrations. Measurement of ATP levels in living cells by quantitative single-cell imaging suggests that ATP levels are not the only determinant of SPB movement. Our results provide novel insight into how SPB movement is regulated by cellular energy status and additional factors such as the medium nutritional composition.
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46
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Cell Cycle-Regulated Transcription of CENP-A by the MBF Complex Ensures Optimal Level of CENP-A for Centromere Formation. Genetics 2019; 211:861-875. [PMID: 30635289 DOI: 10.1534/genetics.118.301745] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/04/2019] [Indexed: 11/18/2022] Open
Abstract
The centromere plays an essential role in chromosome segregation. In most eukaryotes, centromeres are epigenetically defined by the conserved histone H3 variant CENP-A. Proper centromere assembly is dependent upon the tight regulation of CENP-A level. Cell cycle regulation of CENP-A transcription appears to be a universal feature across eukaryotes, but the molecular mechanism underlying the temporal control of CENP-A transcription and how such regulation contributes to centromere function remains elusive. CENP-A in fission yeast has been shown to be transcribed before S phase. Using various synchronization methods, we confirmed that CENP-A transcription occurs at G1, leading to an almost twofold increase of the protein during S phase. Through a genetic screen, we identified the MBF (MluI box-binding factors) complex as a key regulator of temporal control of CENP-A transcription. The periodic transcription of CENP-A is lost in MBF mutants, resulting in CENP-A mislocalization and chromosome segregation defects. We identified the MCB (MluI cell cycle box) motif in the CENP-A promoter, and further showed that the MBF complex binds to the motif to restrict CENP-A transcription to G1. Mutations of the MCB motif cause constitutive CENP-A expression and deleterious effects on cell survival. Using promoters driving transcription to different cell cycle stages, we found that timing of CENP-A transcription is dispensable for its centromeric localization. Our data instead indicate that cell cycle-regulated CENP-A transcription is a key step to ensure that a proper amount of CENP-A is generated across generations. This study provides mechanistic insights into the regulation of cell cycle-dependent CENP-A transcription, as well as its importance on centromere function.
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Nishimura K, Komiya M, Hori T, Itoh T, Fukagawa T. 3D genomic architecture reveals that neocentromeres associate with heterochromatin regions. J Cell Biol 2018; 218:134-149. [PMID: 30396998 PMCID: PMC6314543 DOI: 10.1083/jcb.201805003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 09/21/2018] [Accepted: 10/15/2018] [Indexed: 12/22/2022] Open
Abstract
Although centromeres usually associate with heterochromatic repetitive sequences, such repetitive sequences are not detected around neocentromeres. Nishimura et al. performed systematic 4C analysis of cells containing differently positioned neocentromeres and demonstrate that these neocentromeres commonly associate with distant heterochromatin-rich regions at the 3D level. The centromere is an important genomic locus for chromosomal segregation. Although the centromere is specified by sequence-independent epigenetic mechanisms in most organisms, it is usually composed of highly repetitive sequences, which associate with heterochromatin. We have previously generated various chicken DT40 cell lines containing differently positioned neocentromeres, which do not contain repetitive sequences and do not associate with heterochromatin. In this study, we performed systematic 4C analysis using three cell lines containing differently positioned neocentromeres to identify neocentromere-associated regions at the 3D level. This analysis reveals that these neocentromeres commonly associate with specific heterochromatin-rich regions, which were distantly located from neocentromeres. In addition, we demonstrate that centromeric chromatin adopts a compact structure, and centromere clustering also occurs in vertebrate interphase nuclei. Interestingly, the occurrence of centromere–heterochromatin associations depend on CENP-H, but not CENP-C. Our analyses provide an insight into understanding the 3D architecture of the genome, including the centromeres.
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Affiliation(s)
- Kohei Nishimura
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Masataka Komiya
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | - Tetsuya Hori
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Takehiko Itoh
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | - Tatsuo Fukagawa
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
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Winter DJ, Ganley ARD, Young CA, Liachko I, Schardl CL, Dupont PY, Berry D, Ram A, Scott B, Cox MP. Repeat elements organise 3D genome structure and mediate transcription in the filamentous fungus Epichloë festucae. PLoS Genet 2018; 14:e1007467. [PMID: 30356280 PMCID: PMC6218096 DOI: 10.1371/journal.pgen.1007467] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 11/05/2018] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
Structural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organisation influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus, Epichloë festucae. We use Hi-C data to examine the three-dimensional organisation of the genome, and RNA-seq data to investigate how Epichloë genome structure contributes to the suite of transcriptional changes needed to maintain symbiotic relationships with the grass host. Our results reveal a genome in which very repeat-rich blocks of DNA with discrete boundaries are interspersed by gene-rich sequences that are almost repeat-free. In contrast to other species reported to date, the three-dimensional structure of the genome is anchored by these repeat blocks, which act to isolate transcription in neighbouring gene-rich regions. Genes that are differentially expressed in planta are enriched near the boundaries of these repeat-rich blocks, suggesting that their three-dimensional orientation partly encodes and regulates the symbiotic relationship formed by this organism.
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Affiliation(s)
- David J. Winter
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | - Austen R. D. Ganley
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Carolyn A. Young
- Noble Research Institute, LLC, Ardmore, Oklahoma, United States of America
| | - Ivan Liachko
- Phase Genomics Inc, Seattle, Washington, United States of America
| | - Christopher L. Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Pierre-Yves Dupont
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Daniel Berry
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Arvina Ram
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Barry Scott
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Murray P. Cox
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
- * E-mail:
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Fission Yeast CENP-C (Cnp3) Plays a Role in Restricting the Site of CENP-A Accumulation. G3-GENES GENOMES GENETICS 2018; 8:2723-2733. [PMID: 29925533 PMCID: PMC6071599 DOI: 10.1534/g3.118.200486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The centromere is a chromosomal locus where a microtubule attachment site, termed kinetochore, is assembled in mitosis. In most eukaryotes, with the exception of holocentric species, each chromosome contains a single distinct centromere. A chromosome with an additional centromere undergoes successive rounds of anaphase bridge formation and breakage, or triggers a cell cycle arrest imposed by DNA damage and replication checkpoints. We report here a study in Schizosaccharomyces pombe to characterize a mutant (cnp3-1) in a gene encoding a homolog of mammalian centromere-specific protein, CENP-C. At the restrictive temperature 36°, the Cnp3-1 mutant protein loses its localization at the centromere. In the cnp3-1 mutant, the level of the Cnp1 (a homolog of a centromere-specific histone CENP-A) also decreases at the centromere. Interestingly, the cnp3-1 mutant is prone to promiscuous accumulation of Cnp1 at non-centromeric regions, when Cnp1 is present in excess. Unlike the wild type protein, Cnp3-1 mutant protein is found at the sites of promiscuous accumulation of Cnp1, suggesting that Cnp3-1 may stabilize or promote accumulation of Cnp1 at non-centromeric regions. From these results, we infer the role of Cnp3 in restricting the site of accumulation of Cnp1 and thus to prevent formation of de novo centromeres.
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Duplication and Nuclear Envelope Insertion of the Yeast Microtubule Organizing Centre, the Spindle Pole Body. Cells 2018; 7:cells7050042. [PMID: 29748517 PMCID: PMC5981266 DOI: 10.3390/cells7050042] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 11/16/2022] Open
Abstract
The main microtubule organizing centre in the unicellular model organisms Saccharomyces cerevisiae and Schizosaccharomyces pompe is the spindle pole body (SPB). The SPB is a multilayer structure, which duplicates exactly once per cell cycle. Unlike higher eukaryotic cells, both yeast model organisms undergo mitosis without breakdown of the nuclear envelope (NE), a so-called closed mitosis. Therefore, in order to simultaneously nucleate nuclear and cytoplasmic MTs, it is vital to embed the SPB into the NE at least during mitosis, similarly to the nuclear pore complex (NPC). This review aims to embrace the current knowledge of the SPB duplication cycle with special emphasis on the critical step of the insertion of the new SPB into the NE.
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