1
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Dumont A, Mendiboure N, Savocco J, Anani L, Moreau P, Thierry A, Modolo L, Jost D, Piazza A. Mechanism of homology search expansion during recombinational DNA break repair in Saccharomyces cerevisiae. Mol Cell 2024; 84:3237-3253.e6. [PMID: 39178861 DOI: 10.1016/j.molcel.2024.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 06/26/2024] [Accepted: 08/02/2024] [Indexed: 08/26/2024]
Abstract
Homology search is a central step of DNA double-strand break (DSB) repair by homologous recombination (HR). How it operates in cells remains elusive. We developed a Hi-C-based methodology to map single-stranded DNA (ssDNA) contacts genome-wide in S. cerevisiae, which revealed two main homology search phases. Initial search conducted by short Rad51-ssDNA nucleoprotein filaments (NPFs) is confined in cis by cohesin-mediated chromatin loop folding. Progressive growth of stiff NPFs enables exploration of distant genomic sites. Long-range resection drives this transition from local to genome-wide search by increasing the probability of assembling extensive NPFs. DSB end-tethering promotes coordinated search by opposite NPFs. Finally, an autonomous genetic element on chromosome III engages the NPF, which stimulates homology search in its vicinity. This work reveals the mechanism of the progressive expansion of homology search that is orchestrated by chromatin organizers, long-range resection, end-tethering, and specialized genetic elements and that exploits the stiff NPF structure conferred by Rad51 oligomerization.
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Affiliation(s)
- Agnès Dumont
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, 46 Allée d'Italie, 69007 Lyon, France
| | - Nicolas Mendiboure
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, 46 Allée d'Italie, 69007 Lyon, France
| | - Jérôme Savocco
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, 46 Allée d'Italie, 69007 Lyon, France
| | - Loqmen Anani
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, 46 Allée d'Italie, 69007 Lyon, France
| | - Pierrick Moreau
- Unité Régulation spatiale des génomes, Institut Pasteur, CNRS UMR3525, 75015 Paris, France
| | - Agnès Thierry
- Unité Régulation spatiale des génomes, Institut Pasteur, CNRS UMR3525, 75015 Paris, France
| | - Laurent Modolo
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, 46 Allée d'Italie, 69007 Lyon, France
| | - Daniel Jost
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, 46 Allée d'Italie, 69007 Lyon, France
| | - Aurèle Piazza
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, 46 Allée d'Italie, 69007 Lyon, France.
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2
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Sacristan C, Samejima K, Ruiz LA, Deb M, Lambers MLA, Buckle A, Brackley CA, Robertson D, Hori T, Webb S, Kiewisz R, Bepler T, van Kwawegen E, Risteski P, Vukušić K, Tolić IM, Müller-Reichert T, Fukagawa T, Gilbert N, Marenduzzo D, Earnshaw WC, Kops GJPL. Vertebrate centromeres in mitosis are functionally bipartite structures stabilized by cohesin. Cell 2024; 187:3006-3023.e26. [PMID: 38744280 PMCID: PMC11164432 DOI: 10.1016/j.cell.2024.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 01/30/2024] [Accepted: 04/14/2024] [Indexed: 05/16/2024]
Abstract
Centromeres are scaffolds for the assembly of kinetochores that ensure chromosome segregation during cell division. How vertebrate centromeres obtain a three-dimensional structure to accomplish their primary function is unclear. Using super-resolution imaging, capture-C, and polymer modeling, we show that vertebrate centromeres are partitioned by condensins into two subdomains during mitosis. The bipartite structure is found in human, mouse, and chicken cells and is therefore a fundamental feature of vertebrate centromeres. Super-resolution imaging and electron tomography reveal that bipartite centromeres assemble bipartite kinetochores, with each subdomain binding a distinct microtubule bundle. Cohesin links the centromere subdomains, limiting their separation in response to spindle forces and avoiding merotelic kinetochore-spindle attachments. Lagging chromosomes during cancer cell divisions frequently have merotelic attachments in which the centromere subdomains are separated and bioriented. Our work reveals a fundamental aspect of vertebrate centromere biology with implications for understanding the mechanisms that guarantee faithful chromosome segregation.
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Affiliation(s)
- Carlos Sacristan
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Kumiko Samejima
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK.
| | - Lorena Andrade Ruiz
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Moonmoon Deb
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Maaike L A Lambers
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Adam Buckle
- MRC Human Genetics Unit, Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Chris A Brackley
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Daniel Robertson
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Tetsuya Hori
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Shaun Webb
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Robert Kiewisz
- Simons Machine Learning Center, New York Structural Biology Center, New York, NY 10027, USA; Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, Cantoblanco, Madrid 28049, Spain
| | - Tristan Bepler
- Simons Machine Learning Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Eloïse van Kwawegen
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands
| | | | | | | | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Tatsuo Fukagawa
- Laboratory of Chromosome Biology, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Nick Gilbert
- MRC Human Genetics Unit, Institute of Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Davide Marenduzzo
- SUPA School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK.
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), and University Medical Center Utrecht, Utrecht, the Netherlands.
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3
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Xu J, Xu X, Huang D, Luo Y, Lin L, Bai X, Zheng Y, Yang Q, Cheng Y, Huang A, Shi J, Bo X, Gu J, Chen H. A comprehensive benchmarking with interpretation and operational guidance for the hierarchy of topologically associating domains. Nat Commun 2024; 15:4376. [PMID: 38782890 PMCID: PMC11116433 DOI: 10.1038/s41467-024-48593-7] [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: 09/18/2023] [Accepted: 05/03/2024] [Indexed: 05/25/2024] Open
Abstract
Topologically associating domains (TADs), megabase-scale features of chromatin spatial architecture, are organized in a domain-within-domain TAD hierarchy. Within TADs, the inner and smaller subTADs not only manifest cell-to-cell variability, but also precisely regulate transcription and differentiation. Although over 20 TAD callers are able to detect TAD, their usability in biomedicine is confined by a disagreement of outputs and a limit in understanding TAD hierarchy. We compare 13 computational tools across various conditions and develop a metric to evaluate the similarity of TAD hierarchy. Although outputs of TAD hierarchy at each level vary among callers, data resolutions, sequencing depths, and matrices normalization, they are more consistent when they have a higher similarity of larger TADs. We present comprehensive benchmarking of TAD hierarchy callers and operational guidance to researchers of life science researchers. Moreover, by simulating the mixing of different types of cells, we confirm that TAD hierarchy is generated not simply from stacking Hi-C heatmaps of heterogeneous cells. Finally, we propose an air conditioner model to decipher the role of TAD hierarchy in transcription.
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Affiliation(s)
- Jingxuan Xu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Surgery, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Xiang Xu
- Academy of Military Medical Science, Beijing, 100850, China
| | - Dandan Huang
- Department of Oncology, Peking University Shougang Hospital, Beijing, China
- Center for Precision Diagnosis and Treatment of Colorectal Cancer and Inflammatory Diseases, Peking University Health Science Center, Beijing, China
| | - Yawen Luo
- Academy of Military Medical Science, Beijing, 100850, China
| | - Lin Lin
- Academy of Military Medical Science, Beijing, 100850, China
- School of Computer Science and Information Technology& KLAS, Northeast Normal University, Changchun, China
| | - Xuemei Bai
- Academy of Military Medical Science, Beijing, 100850, China
| | - Yang Zheng
- Academy of Military Medical Science, Beijing, 100850, China
| | - Qian Yang
- Academy of Military Medical Science, Beijing, 100850, China
| | - Yu Cheng
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Surgery, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - An Huang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Surgery, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Jingyi Shi
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Surgery, Peking University Cancer Hospital & Institute, Beijing, 100142, China
| | - Xiaochen Bo
- Academy of Military Medical Science, Beijing, 100850, China.
| | - Jin Gu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Surgery, Peking University Cancer Hospital & Institute, Beijing, 100142, China.
- Department of Oncology, Peking University Shougang Hospital, Beijing, China.
- Center for Precision Diagnosis and Treatment of Colorectal Cancer and Inflammatory Diseases, Peking University Health Science Center, Beijing, China.
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.
- Peking University International Cancer Institute, Beijing, China.
| | - Hebing Chen
- Academy of Military Medical Science, Beijing, 100850, China.
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4
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Abdennur N, Abraham S, Fudenberg G, Flyamer IM, Galitsyna AA, Goloborodko A, Imakaev M, Oksuz BA, Venev SV, Xiao Y. Cooltools: Enabling high-resolution Hi-C analysis in Python. PLoS Comput Biol 2024; 20:e1012067. [PMID: 38709825 PMCID: PMC11098495 DOI: 10.1371/journal.pcbi.1012067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 05/16/2024] [Accepted: 04/10/2024] [Indexed: 05/08/2024] Open
Abstract
Chromosome conformation capture (3C) technologies reveal the incredible complexity of genome organization. Maps of increasing size, depth, and resolution are now used to probe genome architecture across cell states, types, and organisms. Larger datasets add challenges at each step of computational analysis, from storage and memory constraints to researchers' time; however, analysis tools that meet these increased resource demands have not kept pace. Furthermore, existing tools offer limited support for customizing analysis for specific use cases or new biology. Here we introduce cooltools (https://github.com/open2c/cooltools), a suite of computational tools that enables flexible, scalable, and reproducible analysis of high-resolution contact frequency data. Cooltools leverages the widely-adopted cooler format which handles storage and access for high-resolution datasets. Cooltools provides a paired command line interface (CLI) and Python application programming interface (API), which respectively facilitate workflows on high-performance computing clusters and in interactive analysis environments. In short, cooltools enables the effective use of the latest and largest genome folding datasets.
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Affiliation(s)
- Open2C
- https://open2c.github.io/
| | - Nezar Abdennur
- Department of Genomics and Computational Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Sameer Abraham
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Geoffrey Fudenberg
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California, United States of America
| | - Ilya M. Flyamer
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Aleksandra A. Galitsyna
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Anton Goloborodko
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Maxim Imakaev
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States of America
| | - Betul A. Oksuz
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Sergey V. Venev
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Yao Xiao
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California, United States of America
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5
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Golov AK, Gavrilov AA. Cohesin-Dependent Loop Extrusion: Molecular Mechanics and Role in Cell Physiology. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:601-625. [PMID: 38831499 DOI: 10.1134/s0006297924040023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 12/29/2023] [Accepted: 02/15/2024] [Indexed: 06/05/2024]
Abstract
The most prominent representatives of multisubunit SMC complexes, cohesin and condensin, are best known as structural components of mitotic chromosomes. It turned out that these complexes, as well as their bacterial homologues, are molecular motors, the ATP-dependent movement of these complexes along DNA threads leads to the formation of DNA loops. In recent years, we have witnessed an avalanche-like accumulation of data on the process of SMC dependent DNA looping, also known as loop extrusion. This review briefly summarizes the current understanding of the place and role of cohesin-dependent extrusion in cell physiology and presents a number of models describing the potential molecular mechanism of extrusion in a most compelling way. We conclude the review with a discussion of how the capacity of cohesin to extrude DNA loops may be mechanistically linked to its involvement in sister chromatid cohesion.
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Affiliation(s)
- Arkadiy K Golov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
- Technion - Israel Institute of Technology, Haifa, 3525433, Israel
| | - Alexey A Gavrilov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
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6
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Dreyer J, Ricci G, van den Berg J, Bhardwaj V, Funk J, Armstrong C, van Batenburg V, Sine C, VanInsberghe MA, Marsman R, Mandemaker IK, di Sanzo S, Costantini J, Manzo SG, Biran A, Burny C, Völker-Albert M, Groth A, Spencer SL, van Oudenaarden A, Mattiroli F. Acute multi-level response to defective de novo chromatin assembly in S-phase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.22.586291. [PMID: 38585916 PMCID: PMC10996472 DOI: 10.1101/2024.03.22.586291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Long-term perturbation of de novo chromatin assembly during DNA replication has profound effects on epigenome maintenance and cell fate. The early mechanistic origin of these defects is unknown. Here, we combine acute degradation of Chromatin Assembly Factor 1 (CAF-1), a key player in de novo chromatin assembly, with single-cell genomics, quantitative proteomics, and live-microscopy to uncover these initiating mechanisms in human cells. CAF-1 loss immediately slows down DNA replication speed and renders nascent DNA hyperaccessible. A rapid cellular response, distinct from canonical DNA damage signaling, is triggered and lowers histone mRNAs. As a result, histone variants usage and their modifications are altered, limiting transcriptional fidelity and delaying chromatin maturation within a single S-phase. This multi-level response induces a cell-cycle arrest after mitosis. Our work reveals the immediate consequences of defective de novo chromatin assembly during DNA replication, explaining how at later times the epigenome and cell fate can be altered.
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Affiliation(s)
- Jan Dreyer
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Giulia Ricci
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Jeroen van den Berg
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Oncode Institute, The Netherlands
| | - Vivek Bhardwaj
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Oncode Institute, The Netherlands
| | - Janina Funk
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Claire Armstrong
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Vincent van Batenburg
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Oncode Institute, The Netherlands
| | - Chance Sine
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Michael A. VanInsberghe
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Oncode Institute, The Netherlands
| | - Richard Marsman
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Imke K. Mandemaker
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Simone di Sanzo
- MOLEQLAR Analytics GmbH, Rosenheimer Street 141 h, 81671 Munich, Germany
| | - Juliette Costantini
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Stefano G. Manzo
- Oncode Institute, The Netherlands
- Division of Gene Regulation, Netherlands Cancer Institute, The Netherlands
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Alva Biran
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen 2200, Denmark
- Biotech Research & Innovation Centre, University of Copenhagen, Copenhagen 2200, Denmark
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen 2200, Denmark
| | - Claire Burny
- MOLEQLAR Analytics GmbH, Rosenheimer Street 141 h, 81671 Munich, Germany
| | | | - Anja Groth
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen 2200, Denmark
- Biotech Research & Innovation Centre, University of Copenhagen, Copenhagen 2200, Denmark
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen 2200, Denmark
| | - Sabrina L. Spencer
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80303, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Alexander van Oudenaarden
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Oncode Institute, The Netherlands
| | - Francesca Mattiroli
- Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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7
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Ochs F, Green C, Szczurek AT, Pytowski L, Kolesnikova S, Brown J, Gerlich DW, Buckle V, Schermelleh L, Nasmyth KA. Sister chromatid cohesion is mediated by individual cohesin complexes. Science 2024; 383:1122-1130. [PMID: 38452070 DOI: 10.1126/science.adl4606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/26/2024] [Indexed: 03/09/2024]
Abstract
Eukaryotic genomes are organized by loop extrusion and sister chromatid cohesion, both mediated by the multimeric cohesin protein complex. Understanding how cohesin holds sister DNAs together, and how loss of cohesion causes age-related infertility in females, requires knowledge as to cohesin's stoichiometry in vivo. Using quantitative super-resolution imaging, we identified two discrete populations of chromatin-bound cohesin in postreplicative human cells. Whereas most complexes appear dimeric, cohesin that localized to sites of sister chromatid cohesion and associated with sororin was exclusively monomeric. The monomeric stoichiometry of sororin:cohesin complexes demonstrates that sister chromatid cohesion is conferred by individual cohesin rings, a key prediction of the proposal that cohesion arises from the co-entrapment of sister DNAs.
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Affiliation(s)
- Fena Ochs
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Charlotte Green
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | | | - Lior Pytowski
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Sofia Kolesnikova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, 1030 Vienna Austria
| | - Jill Brown
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - Daniel Wolfram Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna Austria
| | - Veronica Buckle
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
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8
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Liu T, Qiu QT, Hua KJ, Ma BG. Chromosome structure modeling tools and their evaluation in bacteria. Brief Bioinform 2024; 25:bbae044. [PMID: 38385874 PMCID: PMC10883143 DOI: 10.1093/bib/bbae044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/31/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024] Open
Abstract
The three-dimensional (3D) structure of bacterial chromosomes is crucial for understanding chromosome function. With the growing availability of high-throughput chromosome conformation capture (3C/Hi-C) data, the 3D structure reconstruction algorithms have become powerful tools to study bacterial chromosome structure and function. It is highly desired to have a recommendation on the chromosome structure reconstruction tools to facilitate the prokaryotic 3D genomics. In this work, we review existing chromosome 3D structure reconstruction algorithms and classify them based on their underlying computational models into two categories: constraint-based modeling and thermodynamics-based modeling. We briefly compare these algorithms utilizing 3C/Hi-C datasets and fluorescence microscopy data obtained from Escherichia coli and Caulobacter crescentus, as well as simulated datasets. We discuss current challenges in the 3D reconstruction algorithms for bacterial chromosomes, primarily focusing on software usability. Finally, we briefly prospect future research directions for bacterial chromosome structure reconstruction algorithms.
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Affiliation(s)
- Tong Liu
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Qin-Tian Qiu
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Kang-Jian Hua
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Bin-Guang Ma
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
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9
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Gilbert BR, Luthey-Schulten Z. Replicating Chromosomes in Whole-Cell Models of Bacteria. Methods Mol Biol 2024; 2819:625-653. [PMID: 39028527 DOI: 10.1007/978-1-0716-3930-6_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Computational models of cells cannot be considered complete unless they include the most fundamental process of life, the replication of genetic material. In a recent study, we presented a computational framework to model systems of replicating bacterial chromosomes as polymers at 10 bp resolution with Brownian dynamics. This approach was used to investigate changes in chromosome organization during replication and extend the applicability of an existing whole-cell model (WCM) for a genetically minimal bacterium, JCVI-syn3A, to the entire cell cycle. To achieve cell-scale chromosome structures that are realistic, we modeled the chromosome as a self-avoiding homopolymer with bending and torsional stiffnesses that capture the essential mechanical properties of dsDNA in Syn3A. Additionally, the polymer interacts with ribosomes distributed according to cryo-electron tomograms of Syn3A. The polymer model was further augmented by computational models of loop extrusion by structural maintenance of chromosomes (SMC) protein complexes and topoisomerase action, and the modeling and analysis of multi-fork replication states.
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Affiliation(s)
- Benjamin R Gilbert
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- NSF Science and Technology Center for Quantitative Cell Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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10
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González-Acosta D, Lopes M. DNA replication and replication stress response in the context of nuclear architecture. Chromosoma 2024; 133:57-75. [PMID: 38055079 PMCID: PMC10904558 DOI: 10.1007/s00412-023-00813-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 12/07/2023]
Abstract
The DNA replication process needs to be coordinated with other DNA metabolism transactions and must eventually extend to the full genome, regardless of chromatin status, gene expression, secondary structures and DNA lesions. Completeness and accuracy of DNA replication are crucial to maintain genome integrity, limiting transformation in normal cells and offering targeting opportunities for proliferating cancer cells. DNA replication is thus tightly coordinated with chromatin dynamics and 3D genome architecture, and we are only beginning to understand the underlying molecular mechanisms. While much has recently been discovered on how DNA replication initiation is organised and modulated in different genomic regions and nuclear territories-the so-called "DNA replication program"-we know much less on how the elongation of ongoing replication forks and particularly the response to replication obstacles is affected by the local nuclear organisation. Also, it is still elusive how specific components of nuclear architecture participate in the replication stress response. Here, we review known mechanisms and factors orchestrating replication initiation, and replication fork progression upon stress, focusing on recent evidence linking genome organisation and nuclear architecture with the cellular responses to replication interference, and highlighting open questions and future challenges to explore this exciting new avenue of research.
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Affiliation(s)
| | - Massimo Lopes
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
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11
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Poinsignon T, Gallopin M, Grognet P, Malagnac F, Lelandais G, Poulain P. 3D models of fungal chromosomes to enhance visual integration of omics data. NAR Genom Bioinform 2023; 5:lqad104. [PMID: 38058589 PMCID: PMC10696920 DOI: 10.1093/nargab/lqad104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/11/2023] [Accepted: 11/17/2023] [Indexed: 12/08/2023] Open
Abstract
The functions of eukaryotic chromosomes and their spatial architecture in the nucleus are reciprocally dependent. Hi-C experiments are routinely used to study chromosome 3D organization by probing chromatin interactions. Standard representation of the data has relied on contact maps that show the frequency of interactions between parts of the genome. In parallel, it has become easier to build 3D models of the entire genome based on the same Hi-C data, and thus benefit from the methodology and visualization tools developed for structural biology. 3D modeling of entire genomes leverages the understanding of their spatial organization. However, this opportunity for original and insightful modeling is underexploited. In this paper, we show how seeing the spatial organization of chromosomes can bring new perspectives to omics data integration. We assembled state-of-the-art tools into a workflow that goes from Hi-C raw data to fully annotated 3D models and we re-analysed public omics datasets available for three fungal species. Besides the well-described properties of the spatial organization of their chromosomes (Rabl conformation, hypercoiling and chromosome territories), our results highlighted (i) in Saccharomyces cerevisiae, the backbones of the cohesin anchor regions, which were aligned all along the chromosomes, (ii) in Schizosaccharomyces pombe, the oscillations of the coiling of chromosome arms throughout the cell cycle and (iii) in Neurospora crassa, the massive relocalization of histone marks in mutants of heterochromatin regulators. 3D modeling of the chromosomes brings new opportunities for visual integration of omics data. This holistic perspective supports intuition and lays the foundation for building new concepts.
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Affiliation(s)
- Thibault Poinsignon
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | - Mélina Gallopin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Pierre Grognet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Fabienne Malagnac
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Gaëlle Lelandais
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Pierre Poulain
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
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12
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Nasmyth KA, Lee BG, Roig MB, Löwe J. What AlphaFold tells us about cohesin's retention on and release from chromosomes. eLife 2023; 12:RP88656. [PMID: 37975572 PMCID: PMC10656103 DOI: 10.7554/elife.88656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023] Open
Abstract
Cohesin is a trimeric complex containing a pair of SMC proteins (Smc1 and Smc3) whose ATPase domains at the end of long coiled coils (CC) are interconnected by Scc1. During interphase, it organizes chromosomal DNA topology by extruding loops in a manner dependent on Scc1's association with two large hook-shaped proteins called SA (yeast: Scc3) and Nipbl (Scc2). The latter's replacement by Pds5 recruits Wapl, which induces release from chromatin via a process requiring dissociation of Scc1's N-terminal domain (NTD) from Smc3. If blocked by Esco (Eco)-mediated Smc3 acetylation, cohesin containing Pds5 merely maintains pre-existing loops, but a third fate occurs during DNA replication, when Pds5-containing cohesin associates with Sororin and forms structures that hold sister DNAs together. How Wapl induces and Sororin blocks release has hitherto remained mysterious. In the 20 years since their discovery, not a single testable hypothesis has been proposed as to their role. Here, AlphaFold 2 (AF) three-dimensional protein structure predictions lead us to propose formation of a quarternary complex between Wapl, SA, Pds5, and Scc1's NTD, in which the latter is juxtaposed with (and subsequently sequestered by) a highly conserved cleft within Wapl's C-terminal domain. AF also reveals how Scc1's dissociation from Smc3 arises from a distortion of Smc3's CC induced by engagement of SMC ATPase domains, how Esco acetyl transferases are recruited to Smc3 by Pds5, and how Sororin prevents release by binding to the Smc3/Scc1 interface. Our hypotheses explain the phenotypes of numerous existing mutations and are highly testable.
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Affiliation(s)
- Kim A Nasmyth
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Byung-Gil Lee
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | - Jan Löwe
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
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13
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Soroczynski J, Risca VI. Technological advances in probing 4D genome organization. Curr Opin Cell Biol 2023; 84:102211. [PMID: 37556867 PMCID: PMC10588670 DOI: 10.1016/j.ceb.2023.102211] [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: 04/01/2023] [Revised: 05/13/2023] [Accepted: 06/29/2023] [Indexed: 08/11/2023]
Abstract
The last two decades of work on chromosome conformation in eukaryotic nuclei have revealed a complex and highly regulated hierarchy of architectural features, from self-associating domains and compartmental interactions to locus-specific loops. Recent findings have shown that these structures are dynamic and heterogeneous, with emerging insights into the factors that shape them and implications for the control of transcription and other nuclear processes. Here, we review the latest advances in the DNA sequencing- and microscopy-based technologies for probing these features in space and time (4D) and discuss how they have been combined with complementary approaches such as genetic perturbations, protein and RNA measurements, and modeling to gain mechanistic insights about genome regulation across space and time.
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Affiliation(s)
- Jan Soroczynski
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, 1230 York Ave., Box 176, New York, NY 10065, USA; David Rockefeller Graduate Program in Bioscience, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Viviana I Risca
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University, 1230 York Ave., Box 176, New York, NY 10065, USA.
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14
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Nagasaka K, Davidson IF, Stocsits RR, Tang W, Wutz G, Batty P, Panarotto M, Litos G, Schleiffer A, Gerlich DW, Peters JM. Cohesin mediates DNA loop extrusion and sister chromatid cohesion by distinct mechanisms. Mol Cell 2023; 83:3049-3063.e6. [PMID: 37591243 DOI: 10.1016/j.molcel.2023.07.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 05/28/2023] [Accepted: 07/25/2023] [Indexed: 08/19/2023]
Abstract
Cohesin connects CTCF-binding sites and other genomic loci in cis to form chromatin loops and replicated DNA molecules in trans to mediate sister chromatid cohesion. Whether cohesin uses distinct or related mechanisms to perform these functions is unknown. Here, we describe a cohesin hinge mutant that can extrude DNA into loops but is unable to mediate cohesion in human cells. Our results suggest that the latter defect arises during cohesion establishment. The observation that cohesin's cohesion and loop extrusion activities can be partially separated indicates that cohesin uses distinct mechanisms to perform these two functions. Unexpectedly, the same hinge mutant can also not be stopped by CTCF boundaries as well as wild-type cohesin. This suggests that cohesion establishment and cohesin's interaction with CTCF boundaries depend on related mechanisms and raises the possibility that both require transient hinge opening to entrap DNA inside the cohesin ring.
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Affiliation(s)
- Kota Nagasaka
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Roman R Stocsits
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Wen Tang
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Gordana Wutz
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Paul Batty
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, Vienna 1030, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna 1030, Austria
| | - Melanie Panarotto
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna 1030, Austria
| | - Gabriele Litos
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Alexander Schleiffer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria; Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, Vienna 1030, Austria
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, Vienna 1030, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria.
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15
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Abstract
Many cellular processes require large-scale rearrangements of chromatin structure. Structural maintenance of chromosomes (SMC) protein complexes are molecular machines that can provide structure to chromatin. These complexes can connect DNA elements in cis, walk along DNA, build and processively enlarge DNA loops and connect DNA molecules in trans to hold together the sister chromatids. These DNA-shaping abilities place SMC complexes at the heart of many DNA-based processes, including chromosome segregation in mitosis, transcription control and DNA replication, repair and recombination. In this Review, we discuss the latest insights into how SMC complexes such as cohesin, condensin and the SMC5-SMC6 complex shape DNA to direct these fundamental chromosomal processes. We also consider how SMC complexes, by building chromatin loops, can counteract the natural tendency of alike chromatin regions to cluster. SMC complexes thus control nuclear organization by participating in a molecular tug of war that determines the architecture of our genome.
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Affiliation(s)
- Claire Hoencamp
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Benjamin D Rowland
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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16
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Castellano-Pozo M, Sioutas G, Barroso C, Prince JP, Lopez-Jimenez P, Davy J, Jaso-Tamame AL, Crawley O, Shao N, Page J, Martinez-Perez E. The kleisin subunit controls the function of C. elegans meiotic cohesins by determining the mode of DNA binding and differential regulation by SCC-2 and WAPL-1. eLife 2023; 12:e84138. [PMID: 37650378 PMCID: PMC10497282 DOI: 10.7554/elife.84138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 07/29/2023] [Indexed: 09/01/2023] Open
Abstract
The cohesin complex plays essential roles in chromosome segregation, 3D genome organisation, and DNA damage repair through its ability to modify DNA topology. In higher eukaryotes, meiotic chromosome function, and therefore fertility, requires cohesin complexes containing meiosis-specific kleisin subunits: REC8 and RAD21L in mammals and REC-8 and COH-3/4 in Caenorhabditis elegans. How these complexes perform the multiple functions of cohesin during meiosis and whether this involves different modes of DNA binding or dynamic association with chromosomes is poorly understood. Combining time-resolved methods of protein removal with live imaging and exploiting the temporospatial organisation of the C. elegans germline, we show that REC-8 complexes provide sister chromatid cohesion (SCC) and DNA repair, while COH-3/4 complexes control higher-order chromosome structure. High-abundance COH-3/4 complexes associate dynamically with individual chromatids in a manner dependent on cohesin loading (SCC-2) and removal (WAPL-1) factors. In contrast, low-abundance REC-8 complexes associate stably with chromosomes, tethering sister chromatids from S-phase until the meiotic divisions. Our results reveal that kleisin identity determines the function of meiotic cohesin by controlling the mode and regulation of cohesin-DNA association, and are consistent with a model in which SCC and DNA looping are performed by variant cohesin complexes that coexist on chromosomes.
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Affiliation(s)
| | | | | | - Josh P Prince
- MRC London Institute of Medical SciencesLondonUnited Kingdom
| | | | - Joseph Davy
- MRC London Institute of Medical SciencesLondonUnited Kingdom
| | | | - Oliver Crawley
- MRC London Institute of Medical SciencesLondonUnited Kingdom
| | - Nan Shao
- MRC London Institute of Medical SciencesLondonUnited Kingdom
| | - Jesus Page
- Universidad Autónoma de MadridMadridSpain
| | - Enrique Martinez-Perez
- MRC London Institute of Medical SciencesLondonUnited Kingdom
- Imperial College Faculty of MedicineLondonUnited Kingdom
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17
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Batty P, Langer CCH, Takács Z, Tang W, Blaukopf C, Peters J, Gerlich DW. Cohesin-mediated DNA loop extrusion resolves sister chromatids in G2 phase. EMBO J 2023; 42:e113475. [PMID: 37357575 PMCID: PMC10425840 DOI: 10.15252/embj.2023113475] [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: 01/10/2023] [Revised: 05/26/2023] [Accepted: 06/14/2023] [Indexed: 06/27/2023] Open
Abstract
Genetic information is stored in linear DNA molecules, which are highly folded inside cells. DNA replication along the folded template path yields two sister chromatids that initially occupy the same nuclear region in an intertwined arrangement. Dividing cells must disentangle and condense the sister chromatids into separate bodies such that a microtubule-based spindle can move them to opposite poles. While the spindle-mediated transport of sister chromatids has been studied in detail, the chromosome-intrinsic mechanics presegregating sister chromatids have remained elusive. Here, we show that human sister chromatids resolve extensively already during interphase, in a process dependent on the loop-extruding activity of cohesin, but not that of condensins. Increasing cohesin's looping capability increases sister DNA resolution in interphase nuclei to an extent normally seen only during mitosis, despite the presence of abundant arm cohesion. That cohesin can resolve sister chromatids so extensively in the absence of mitosis-specific activities indicates that DNA loop extrusion is a generic mechanism for segregating replicated genomes, shared across different Structural Maintenance of Chromosomes (SMC) protein complexes in all kingdoms of life.
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Affiliation(s)
- Paul Batty
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna BioCenter (VBC)ViennaAustria
- Vienna BioCenter PhD ProgramDoctoral School of the University of Vienna and Medical University of ViennaViennaAustria
| | - Christoph CH Langer
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna BioCenter (VBC)ViennaAustria
| | - Zsuzsanna Takács
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna BioCenter (VBC)ViennaAustria
| | - Wen Tang
- Research Institute of Molecular Pathology (IMP)Vienna BioCenter (VBC)ViennaAustria
| | - Claudia Blaukopf
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna BioCenter (VBC)ViennaAustria
| | - Jan‐Michael Peters
- Research Institute of Molecular Pathology (IMP)Vienna BioCenter (VBC)ViennaAustria
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA)Vienna BioCenter (VBC)ViennaAustria
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18
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Gilbert BR, Thornburg ZR, Brier TA, Stevens JA, Grünewald F, Stone JE, Marrink SJ, Luthey-Schulten Z. Dynamics of chromosome organization in a minimal bacterial cell. Front Cell Dev Biol 2023; 11:1214962. [PMID: 37621774 PMCID: PMC10445541 DOI: 10.3389/fcell.2023.1214962] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 07/10/2023] [Indexed: 08/26/2023] Open
Abstract
Computational models of cells cannot be considered complete unless they include the most fundamental process of life, the replication and inheritance of genetic material. By creating a computational framework to model systems of replicating bacterial chromosomes as polymers at 10 bp resolution with Brownian dynamics, we investigate changes in chromosome organization during replication and extend the applicability of an existing whole-cell model (WCM) for a genetically minimal bacterium, JCVI-syn3A, to the entire cell-cycle. To achieve cell-scale chromosome structures that are realistic, we model the chromosome as a self-avoiding homopolymer with bending and torsional stiffnesses that capture the essential mechanical properties of dsDNA in Syn3A. In addition, the conformations of the circular DNA must avoid overlapping with ribosomes identitied in cryo-electron tomograms. While Syn3A lacks the complex regulatory systems known to orchestrate chromosome segregation in other bacteria, its minimized genome retains essential loop-extruding structural maintenance of chromosomes (SMC) protein complexes (SMC-scpAB) and topoisomerases. Through implementing the effects of these proteins in our simulations of replicating chromosomes, we find that they alone are sufficient for simultaneous chromosome segregation across all generations within nested theta structures. This supports previous studies suggesting loop-extrusion serves as a near-universal mechanism for chromosome organization within bacterial and eukaryotic cells. Furthermore, we analyze ribosome diffusion under the influence of the chromosome and calculate in silico chromosome contact maps that capture inter-daughter interactions. Finally, we present a methodology to map the polymer model of the chromosome to a Martini coarse-grained representation to prepare molecular dynamics models of entire Syn3A cells, which serves as an ultimate means of validation for cell states predicted by the WCM.
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Affiliation(s)
- Benjamin R. Gilbert
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Zane R. Thornburg
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Troy A. Brier
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Jan A. Stevens
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Fabian Grünewald
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - John E. Stone
- NVIDIA Corporation, Santa Clara, CA, United States
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Siewert J. Marrink
- Molecular Dynamics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
- NSF Center for the Physics of Living Cells, Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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19
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Langer CCH, Mitter M, Stocsits RR, Gerlich DW. HiCognition: a visual exploration and hypothesis testing tool for 3D genomics. Genome Biol 2023; 24:158. [PMID: 37408019 PMCID: PMC10320903 DOI: 10.1186/s13059-023-02996-9] [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: 06/29/2022] [Accepted: 06/25/2023] [Indexed: 07/07/2023] Open
Abstract
Genome browsers facilitate integrated analysis of multiple genomics datasets yet visualize only a few regions at a time and lack statistical functions for extracting meaningful information. We present HiCognition, a visual exploration and machine-learning tool based on a new genomic region set concept, enabling detection of patterns and associations between 3D chromosome conformation and collections of 1D genomics profiles of any type. By revealing how transcription and cohesion subunit isoforms contribute to chromosome conformation, we showcase how the flexible user interface and machine learning tools of HiCognition help to understand the relationship between the structure and function of the genome.
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Affiliation(s)
- Christoph C H Langer
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Michael Mitter
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Roman R Stocsits
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria.
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20
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Jia BB, Jussila A, Kern C, Zhu Q, Ren B. A spatial genome aligner for resolving chromatin architectures from multiplexed DNA FISH. Nat Biotechnol 2023; 41:1004-1017. [PMID: 36593410 PMCID: PMC10344783 DOI: 10.1038/s41587-022-01568-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 10/13/2022] [Indexed: 01/03/2023]
Abstract
Multiplexed fluorescence in situ hybridization (FISH) is a widely used approach for analyzing three-dimensional genome organization, but it is challenging to derive chromosomal conformations from noisy fluorescence signals, and tracing chromatin is not straightforward. Here we report a spatial genome aligner that parses true chromatin signal from noise by aligning signals to a DNA polymer model. Using genomic distances separating imaged loci, our aligner estimates spatial distances expected to separate loci on a polymer in three-dimensional space. Our aligner then evaluates the physical probability observed signals belonging to these loci are connected, thereby tracing chromatin structures. We demonstrate that this spatial genome aligner can efficiently model chromosome architectures from DNA FISH data across multiple scales and be used to predict chromosome ploidies de novo in interphase cells. Reprocessing of previous whole-genome chromosome tracing data with this method indicates the spatial aggregation of sister chromatids in S/G2 phase cells in asynchronous mouse embryonic stem cells and provides evidence for extranumerary chromosomes that remain tightly paired in postmitotic neurons of the adult mouse cortex.
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Affiliation(s)
- Bojing Blair Jia
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, CA, USA
- Medical Scientist Training Program, University of California San Diego, La Jolla, CA, USA
| | - Adam Jussila
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, CA, USA
| | - Colin Kern
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA
| | - Quan Zhu
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA
| | - Bing Ren
- Department of Cellular and Molecular Medicine, Center for Epigenomics, University of California San Diego, La Jolla, CA, USA.
- Ludwig Institute for Cancer Research, La Jolla, CA, USA.
- Institute of Genomic Medicine, Moores Cancer Center, School of Medicine, University of California San Diego, La Jolla, CA, USA.
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21
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Borrie MS, Kraycer PM, Gartenberg MR. Transcription-Driven Translocation of Cohesive and Non-Cohesive Cohesin In Vivo. Mol Cell Biol 2023; 43:254-268. [PMID: 37178128 PMCID: PMC10251789 DOI: 10.1080/10985549.2023.2199660] [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: 01/03/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 05/15/2023] Open
Abstract
Cohesin is a central architectural element of chromosomes that regulates numerous DNA-based events. The complex holds sister chromatids together until anaphase onset and organizes individual chromosomal DNAs into loops and self-associating domains. Purified cohesin diffuses along DNA in an ATP-independent manner but can be propelled by transcribing RNA polymerase. In conjunction with a cofactor, the complex also extrudes DNA loops in an ATP-dependent manner. In this study we examine transcription-driven translocation of cohesin under various conditions in yeast. To this end, obstacles of increasing size were tethered to DNA to act as roadblocks to complexes mobilized by an inducible gene. The obstacles were built from a GFP-lacI core fused to one or more mCherries. A chimera with four mCherries blocked cohesin passage in late G1. During M phase, the threshold barrier depended on the state of cohesion: non-cohesive complexes were also blocked by four mCherries whereas cohesive complexes were blocked by as few as three mCherries. Furthermore cohesive complexes that were stalled at obstacles, in turn, blocked the passage of non-cohesive complexes. That synthetic barriers capture mobilized cohesin demonstrates that transcription-driven complexes translocate processively in vivo. Together, this study reveals unexplored limitations to cohesin movement on chromosomes.
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Affiliation(s)
- Melinda S. Borrie
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Paul M. Kraycer
- Graduate Program in Cellular and Molecular Pharmacology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Marc R. Gartenberg
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Member of The Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
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22
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Davidson IF, Barth R, Zaczek M, van der Torre J, Tang W, Nagasaka K, Janissen R, Kerssemakers J, Wutz G, Dekker C, Peters JM. CTCF is a DNA-tension-dependent barrier to cohesin-mediated loop extrusion. Nature 2023; 616:822-827. [PMID: 37076620 PMCID: PMC10132984 DOI: 10.1038/s41586-023-05961-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 03/16/2023] [Indexed: 04/21/2023]
Abstract
In eukaryotes, genomic DNA is extruded into loops by cohesin1. By restraining this process, the DNA-binding protein CCCTC-binding factor (CTCF) generates topologically associating domains (TADs)2,3 that have important roles in gene regulation and recombination during development and disease1,4-7. How CTCF establishes TAD boundaries and to what extent these are permeable to cohesin is unclear8. Here, to address these questions, we visualize interactions of single CTCF and cohesin molecules on DNA in vitro. We show that CTCF is sufficient to block diffusing cohesin, possibly reflecting how cohesive cohesin accumulates at TAD boundaries, and is also sufficient to block loop-extruding cohesin, reflecting how CTCF establishes TAD boundaries. CTCF functions asymmetrically, as predicted; however, CTCF is dependent on DNA tension. Moreover, CTCF regulates cohesin's loop-extrusion activity by changing its direction and by inducing loop shrinkage. Our data indicate that CTCF is not, as previously assumed, simply a barrier to cohesin-mediated loop extrusion but is an active regulator of this process, whereby the permeability of TAD boundaries can be modulated by DNA tension. These results reveal mechanistic principles of how CTCF controls loop extrusion and genome architecture.
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Affiliation(s)
- Iain F Davidson
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Maciej Zaczek
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
- Children's Cancer Research Institute, St Anna Kinderkrebsforschung, Vienna, Austria
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Wen Tang
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Kota Nagasaka
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Jacob Kerssemakers
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Gordana Wutz
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands.
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria.
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23
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de Wit E, Nora EP. New insights into genome folding by loop extrusion from inducible degron technologies. Nat Rev Genet 2023; 24:73-85. [PMID: 36180596 DOI: 10.1038/s41576-022-00530-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2022] [Indexed: 01/24/2023]
Abstract
Chromatin folds into dynamic loops that often span hundreds of kilobases and physically wire distant loci together for gene regulation. These loops are continuously created, extended and positioned by structural maintenance of chromosomes (SMC) protein complexes, such as condensin and cohesin, and their regulators, including CTCF, in a highly dynamic process known as loop extrusion. Genetic loss of extrusion factors is lethal, complicating their study. Inducible protein degradation technologies enable the depletion of loop extrusion factors within hours, leading to the rapid reconfiguration of chromatin folding. Here, we review how these technologies have changed our understanding of genome organization, upsetting long-held beliefs on its role in transcription. Finally, we examine recent models that attempt to reconcile observations after chronic versus acute perturbations, and discuss future developments in this rapidly developing field of research.
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Affiliation(s)
- Elzo de Wit
- Division of Gene Regulation, Oncode Institute, Amsterdam, the Netherlands.
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, the Netherlands.
| | - Elphège P Nora
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA.
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
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24
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Kariti H, Feld T, Kaplan N. Hypothesis-driven probabilistic modelling enables a principled perspective of genomic compartments. Nucleic Acids Res 2023; 51:1103-1119. [PMID: 36629266 PMCID: PMC9943678 DOI: 10.1093/nar/gkac1258] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/30/2022] [Accepted: 01/10/2023] [Indexed: 01/12/2023] Open
Abstract
The Hi-C method has revolutionized the study of genome organization, yet interpretation of Hi-C interaction frequency maps remains a major challenge. Genomic compartments are a checkered Hi-C interaction pattern suggested to represent the partitioning of the genome into two self-interacting states associated with active and inactive chromatin. Based on a few elementary mechanistic assumptions, we derive a generative probabilistic model of genomic compartments, called deGeco. Testing our model, we find it can explain observed Hi-C interaction maps in a highly robust manner, allowing accurate inference of interaction probability maps from extremely sparse data without any training of parameters. Taking advantage of the interpretability of the model parameters, we then test hypotheses regarding the nature of genomic compartments. We find clear evidence of multiple states, and that these states self-interact with different affinities. We also find that the interaction rules of chromatin states differ considerably within and between chromosomes. Inspecting the molecular underpinnings of a four-state model, we show that a simple classifier can use histone marks to predict the underlying states with 87% accuracy. Finally, we observe instances of mixed-state loci and analyze these loci in single-cell Hi-C maps, finding that mixing of states occurs mainly at the cell level.
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Affiliation(s)
- Hagai Kariti
- Department of Physiology, Biophysics & Systems Biology, Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, Haifa, Israel
| | - Tal Feld
- Department of Physiology, Biophysics & Systems Biology, Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, Haifa, Israel,Viterbi Faculty of Electrical & Computer Engineering, Technion – Israel Institute of Technology, Haifa, Israel
| | - Noam Kaplan
- To whom correspondence should be addressed. Tel: +972 4 8295293;
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25
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Lohia R, Fox N, Gillis J. A global high-density chromatin interaction network reveals functional long-range and trans-chromosomal relationships. Genome Biol 2022; 23:238. [PMID: 36352464 PMCID: PMC9647974 DOI: 10.1186/s13059-022-02790-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 10/10/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chromatin contacts are essential for gene-expression regulation; however, obtaining a high-resolution genome-wide chromatin contact map is still prohibitively expensive owing to large genome sizes and the quadratic scale of pairwise data. Chromosome conformation capture (3C)-based methods such as Hi-C have been extensively used to obtain chromatin contacts. However, since the sparsity of these maps increases with an increase in genomic distance between contacts, long-range or trans-chromatin contacts are especially challenging to sample. RESULTS Here, we create a high-density reference genome-wide chromatin contact map using a meta-analytic approach. We integrate 3600 human, 6700 mouse, and 500 fly Hi-C experiments to create species-specific meta-Hi-C chromatin contact maps with 304 billion, 193 billion, and 19 billion contacts in respective species. We validate that meta-Hi-C contact maps are uniquely powered to capture functional chromatin contacts in both cis and trans. We find that while individual dataset Hi-C networks are largely unable to predict any long-range coexpression (median 0.54 AUC), meta-Hi-C networks perform comparably in both cis and trans (0.65 AUC vs 0.64 AUC). Similarly, for long-range expression quantitative trait loci (eQTL), meta-Hi-C contacts outperform all individual Hi-C experiments, providing an improvement over the conventionally used linear genomic distance-based association. Assessing between species, we find patterns of chromatin contact conservation in both cis and trans and strong associations with coexpression even in species for which Hi-C data is lacking. CONCLUSIONS We have generated an integrated chromatin interaction network which complements a large number of methodological and analytic approaches focused on improved specificity or interpretation. This high-depth "super-experiment" is surprisingly powerful in capturing long-range functional relationships of chromatin interactions, which are now able to predict coexpression, eQTLs, and cross-species relationships. The meta-Hi-C networks are available at https://labshare.cshl.edu/shares/gillislab/resource/HiC/ .
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Affiliation(s)
- Ruchi Lohia
- Stanley Institute for Cognitive Genomics, Cold Spring Harbor Laboratory, Cold Spring Harbor, USA
| | - Nathan Fox
- Stanley Institute for Cognitive Genomics, Cold Spring Harbor Laboratory, Cold Spring Harbor, USA
| | - Jesse Gillis
- Stanley Institute for Cognitive Genomics, Cold Spring Harbor Laboratory, Cold Spring Harbor, USA
- Department of Physiology and Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
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26
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Liu Y, Dekker J. CTCF-CTCF loops and intra-TAD interactions show differential dependence on cohesin ring integrity. Nat Cell Biol 2022; 24:1516-1527. [PMID: 36202971 PMCID: PMC10174090 DOI: 10.1038/s41556-022-00992-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 08/11/2022] [Indexed: 11/08/2022]
Abstract
The ring-like cohesin complex mediates sister-chromatid cohesion by encircling pairs of sister chromatids. Cohesin also extrudes loops along chromatids. Whether the two activities involve similar mechanisms of DNA engagement is not known. We implemented an experimental approach based on isolated nuclei carrying engineered cleavable RAD21 proteins to precisely control cohesin ring integrity so that its role in chromatin looping could be studied under defined experimental conditions. This approach allowed us to identify cohesin complexes with distinct biochemical, and possibly structural, properties that mediate different sets of chromatin loops. When RAD21 is cleaved and the cohesin ring is opened, cohesin complexes at CTCF sites are released from DNA and loops at these elements are lost. In contrast, cohesin-dependent loops within chromatin domains that are not anchored at pairs of CTCF sites are more resistant to RAD21 cleavage. The results show that the cohesin complex mediates loops in different ways depending on the genomic context and suggests that it undergoes structural changes as it dynamically extrudes and encounters CTCF sites.
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Affiliation(s)
- Yu Liu
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Job Dekker
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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27
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Das P, Shen T, McCord RP. Characterizing the variation in chromosome structure ensembles in the context of the nuclear microenvironment. PLoS Comput Biol 2022; 18:e1010392. [PMID: 35969616 PMCID: PMC9410561 DOI: 10.1371/journal.pcbi.1010392] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 08/25/2022] [Accepted: 07/15/2022] [Indexed: 11/23/2022] Open
Abstract
Inside the nucleus, chromosomes are subjected to direct physical interaction between different components, active forces, and thermal noise, leading to the formation of an ensemble of three-dimensional structures. However, it is still not well understood to what extent and how the structural ensemble varies from one chromosome region or cell-type to another. We designed a statistical analysis technique and applied it to single-cell chromosome imaging data to reveal the heterogeneity of individual chromosome structures. By analyzing the resulting structural landscape, we find that the largest dynamic variation is the overall radius of gyration of the chromatin region, followed by domain reorganization within the region. By comparing different human cell-lines and experimental perturbation data using this statistical analysis technique and a network-based similarity quantification approach, we identify both cell-type and condition-specific features of the structural landscapes. We identify a relationship between epigenetic state and the properties of chromosome structure fluctuation and validate this relationship through polymer simulations. Overall, our study suggests that the types of variation in a chromosome structure ensemble are cell-type as well as region-specific and can be attributed to constraints placed on the structure by factors such as variation in epigenetic state. Recent work has revealed principles of how chromosomes are folded and structured inside the human nucleus. It is now even possible to microscopically trace the path of chromosomes in 3D in individual cells. With this data, we can start to examine how much variation exists in chromosome structure and what biological factors may restrict or enhance this variation. Are chromosomes stuck in just a few possible positions or do they move around more freely, sampling many configurations? Here, we use a mathematical approach to compare chromosome structure variation in different cell types, at different locations along the genome, and when key structural proteins are removed. Through these comparisons and dynamic simulations of chromosome behavior, we identify factors that may constrain or promote variation in chromosome structure.
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Affiliation(s)
- Priyojit Das
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Tongye Shen
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
- Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Rachel Patton McCord
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
- Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail:
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28
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Fleck K, Raj R, Erceg J. The 3D genome landscape: Diverse chromosomal interactions and their functional implications. Front Cell Dev Biol 2022; 10:968145. [PMID: 36036013 PMCID: PMC9402908 DOI: 10.3389/fcell.2022.968145] [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: 06/13/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Genome organization includes contacts both within a single chromosome and between distinct chromosomes. Thus, regulatory organization in the nucleus may include interplay of these two types of chromosomal interactions with genome activity. Emerging advances in omics and single-cell imaging technologies have allowed new insights into chromosomal contacts, including those of homologs and sister chromatids, and their significance to genome function. In this review, we highlight recent studies in this field and discuss their impact on understanding the principles of chromosome organization and associated functional implications in diverse cellular processes. Specifically, we describe the contributions of intra-chromosomal, inter-homolog, and inter-sister chromatid contacts to genome organization and gene expression.
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Affiliation(s)
- Katherine Fleck
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Romir Raj
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
| | - Jelena Erceg
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, United States
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, United States
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT, United States
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29
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Sou IF, Hamer G, Tee WW, Vader G, McClurg UL. Cancer and meiotic gene expression: Two sides of the same coin? Curr Top Dev Biol 2022; 151:43-68. [PMID: 36681477 DOI: 10.1016/bs.ctdb.2022.06.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Meiosis increases genetic diversity in offspring by generating genetically unique haploid gametes with reshuffled chromosomes. This process requires a specialized set of meiotic proteins, which facilitate chromosome recombination and segregation. However, re-expression of meiotic proteins in mitosis can have catastrophic oncogenic consequences and aberrant expression of meiotic proteins is a common occurrence in human tumors. Mechanistically, re-activation of meiotic genes in cancer promotes oncogenesis likely because cancers-conversely to healthy mitosis-are fueled by genetic instability which promotes tumor evolution, and evasion of immune response and treatment pressure. In this review, we explore similarities between meiotic and cancer cells with a particular focus on the oncogenic activation of meiotic genes in cancer. We emphasize the role of histones and their modifications, DNA methylation, genome organization, R-loops and the availability of distal enhancers.
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Affiliation(s)
- Ieng Fong Sou
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom; Chromatin Dynamics and Disease Epigenetics Group, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Geert Hamer
- Center for Reproductive Medicine, Reproductive Biology Laboratory, Amsterdam Reproduction and Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Wee-Wei Tee
- Chromatin Dynamics and Disease Epigenetics Group, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Gerben Vader
- Center for Reproductive Medicine, Reproductive Biology Laboratory, Amsterdam Reproduction and Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands; Section of Oncogenetics, Department of Human Genetics, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands; Cancer Center Amsterdam, Cancer Biology and Immunology, Amsterdam, The Netherlands
| | - Urszula Lucja McClurg
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom.
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30
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Srinivasan D, Shisode T, Shrinet J, Fraser P. Chromosome organization through the cell cycle at a glance. J Cell Sci 2022; 135:275498. [PMID: 35608019 DOI: 10.1242/jcs.244004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Genome organization and the three-dimensional folding of chromosomes are now seen as major contributors to nearly all nuclear functions including gene regulation, replication and repair. Recent studies have shown that in addition to the dramatic metamorphoses in chromosome conformation associated with entry to, and exit from mitosis, chromosomes undergo continual conformational changes throughout interphase with differential dynamics in loop structure, topological domains, compartments and lamina-associated domains. Understanding and accounting for these cell-cycle-dependent conformational changes is essential for the interpretation of data from a growing array of powerful molecular techniques to investigate genome conformation function, and to identify the molecules and mechanisms that drive chromosome conformational changes. In this Cell Science at a Glance article and the accompanying poster, we review Hi-C and microscopy studies describing cell-cycle-dependent conformational changes in chromosome structure.
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Affiliation(s)
- Divyaa Srinivasan
- Department of Biological Science, Florida State University, Tallahassee, FL 32304, USA
| | - Tarak Shisode
- Department of Biological Science, Florida State University, Tallahassee, FL 32304, USA
| | - Jatin Shrinet
- Department of Biological Science, Florida State University, Tallahassee, FL 32304, USA
| | - Peter Fraser
- Department of Biological Science, Florida State University, Tallahassee, FL 32304, USA
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31
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Sister chromatid-sensitive Hi-C to map the conformation of replicated genomes. Nat Protoc 2022; 17:1486-1517. [PMID: 35478248 DOI: 10.1038/s41596-022-00687-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 01/19/2022] [Indexed: 12/23/2022]
Abstract
Chromosome conformation capture (Hi-C) techniques map the 3D organization of entire genomes. How sister chromatids fold in replicated chromosomes, however, cannot be determined with conventional Hi-C because of the identical DNA sequences of sister chromatids. Here, we present a protocol for sister chromatid-sensitive Hi-C (scsHi-C) that enables the distinction of DNA contacts within individual sister chromatids (cis sister contacts) from those between sister chromatids (trans sister contacts), thereby allowing investigation of the organization of replicated genomes. scsHi-C is based on live-cell labeling of nascent DNA by the synthetic nucleoside 4-thio-thymidine (4sT), which incorporates into a distinct DNA strand on each sister chromatid because of semi-conservative DNA replication. After purification of genomic DNA and in situ Hi-C library preparation, 4sT is chemically converted into 5-methyl-cytosine in the presence of OsO4/NH4Cl to introduce T-to-C signature point mutations on 4sT-labeled DNA. The Hi-C library is then sequenced, and ligated fragments are assigned to sister chromatids on the basis of strand orientation and the presence of signature mutations. The ensemble of scsHi-C contacts thereby represents genome-wide contact probabilities within and across sister chromatids. scsHi-C can be completed in 2 weeks, has been successfully applied in HeLa cells and can potentially be established for any cell type that allows proper cell cycle synchronization and incorporation of sufficient amounts of 4sT. The genome-wide maps of replicated chromosomes detected by scsHi-C enable investigation of the molecular mechanisms shaping sister chromatid topologies and the relevance of sister chromatid conformation in crucial processes like DNA repair, mitotic chromosome formation and potentially other biological processes.
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32
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A walk through the SMC cycle: From catching DNAs to shaping the genome. Mol Cell 2022; 82:1616-1630. [PMID: 35477004 DOI: 10.1016/j.molcel.2022.04.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 02/02/2022] [Accepted: 04/04/2022] [Indexed: 12/16/2022]
Abstract
SMC protein complexes are molecular machines that provide structure to chromosomes. These complexes bridge DNA elements and by doing so build DNA loops in cis and hold together the sister chromatids in trans. We discuss how drastic conformational changes allow SMC complexes to build such intricate DNA structures. The tight regulation of these complexes controls fundamental chromosomal processes such as transcription, recombination, repair, and mitosis.
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33
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van Schie JJM, de Lange J. The Interplay of Cohesin and the Replisome at Processive and Stressed DNA Replication Forks. Cells 2021; 10:3455. [PMID: 34943967 PMCID: PMC8700348 DOI: 10.3390/cells10123455] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 12/12/2022] Open
Abstract
The cohesin complex facilitates faithful chromosome segregation by pairing the sister chromatids after DNA replication until mitosis. In addition, cohesin contributes to proficient and error-free DNA replication. Replisome progression and establishment of sister chromatid cohesion are intimately intertwined processes. Here, we review how the key factors in DNA replication and cohesion establishment cooperate in unperturbed conditions and during DNA replication stress. We discuss the detailed molecular mechanisms of cohesin recruitment and the entrapment of replicated sister chromatids at the replisome, the subsequent stabilization of sister chromatid cohesion via SMC3 acetylation, as well as the role and regulation of cohesin in the response to DNA replication stress.
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Affiliation(s)
- Janne J. M. van Schie
- Cancer Center Amsterdam, Department of Human Genetics, Section Oncogenetics, Amsterdam University Medical Centers, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
| | - Job de Lange
- Cancer Center Amsterdam, Department of Human Genetics, Section Oncogenetics, Amsterdam University Medical Centers, De Boelelaan 1118, 1081 HV Amsterdam, The Netherlands
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34
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Perspectives for the reconstruction of 3D chromatin conformation using single cell Hi-C data. PLoS Comput Biol 2021; 17:e1009546. [PMID: 34793453 PMCID: PMC8601426 DOI: 10.1371/journal.pcbi.1009546] [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: 06/22/2021] [Accepted: 10/08/2021] [Indexed: 11/19/2022] Open
Abstract
Construction of chromosomes 3D models based on single cell Hi-C data constitute an important challenge. We present a reconstruction approach, DPDchrom, that incorporates basic knowledge whether the reconstructed conformation should be coil-like or globular and spring relaxation at contact sites. In contrast to previously published protocols, DPDchrom can naturally form globular conformation due to the presence of explicit solvent. Benchmarking of this and several other methods on artificial polymer models reveals similar reconstruction accuracy at high contact density and DPDchrom advantage at low contact density. To compare 3D structures insensitively to spatial orientation and scale, we propose the Modified Jaccard Index. We analyzed two sources of the contact dropout: contact radius change and random contact sampling. We found that the reconstruction accuracy exponentially depends on the number of contacts per genomic bin allowing to estimate the reconstruction accuracy in advance. We applied DPDchrom to model chromosome configurations based on single-cell Hi-C data of mouse oocytes and found that these configurations differ significantly from a random one, that is consistent with other studies.
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35
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Piazza A, Bordelet H, Dumont A, Thierry A, Savocco J, Girard F, Koszul R. Cohesin regulates homology search during recombinational DNA repair. Nat Cell Biol 2021; 23:1176-1186. [PMID: 34750581 DOI: 10.1038/s41556-021-00783-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 09/27/2021] [Indexed: 02/06/2023]
Abstract
Homologous recombination repairs DNA double-strand breaks (DSB) using an intact dsDNA molecule as a template. It entails a homology search step, carried out along a conserved RecA/Rad51-ssDNA filament assembled on each DSB end. Whether, how and to what extent a DSB impacts chromatin folding, and how this (re)organization in turns influences the homology search process, remain ill-defined. Here we characterize two layers of spatial chromatin reorganization following DSB formation in Saccharomyces cerevisiae. Although cohesin folds chromosomes into cohesive arrays of ~20-kb-long chromatin loops as cells arrest in G2/M, the DSB-flanking regions interact locally in a resection- and 9-1-1 clamp-dependent manner, independently of cohesin, Mec1ATR, Rad52 and Rad51. This local structure blocks cohesin progression, constraining the DSB region at the base of a loop. Functionally, cohesin promotes DSB-dsDNA interactions and donor identification in cis, while inhibiting them in trans. This study identifies multiple direct and indirect ways by which cohesin regulates homology search during recombinational DNA repair.
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Affiliation(s)
- Aurèle Piazza
- Institut Pasteur, CNRS UMR3525, Unité Régulation Spatiale des Génomes, F-75015, Paris, France.
- Université de Lyon, ENS de Lyon, Université Claude Bernard, Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR5239, INSERM U1210, 46 allée d'Italie, 69007, Lyon, France.
| | - Hélène Bordelet
- Institut Pasteur, CNRS UMR3525, Unité Régulation Spatiale des Génomes, F-75015, Paris, France
- Université de Lyon, ENS de Lyon, Université Claude Bernard, Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR5239, INSERM U1210, 46 allée d'Italie, 69007, Lyon, France
| | - Agnès Dumont
- Université de Lyon, ENS de Lyon, Université Claude Bernard, Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR5239, INSERM U1210, 46 allée d'Italie, 69007, Lyon, France
| | - Agnès Thierry
- Institut Pasteur, CNRS UMR3525, Unité Régulation Spatiale des Génomes, F-75015, Paris, France
| | - Jérôme Savocco
- Université de Lyon, ENS de Lyon, Université Claude Bernard, Laboratoire de Biologie et Modélisation de la Cellule, CNRS UMR5239, INSERM U1210, 46 allée d'Italie, 69007, Lyon, France
| | - Fabien Girard
- Institut Pasteur, CNRS UMR3525, Unité Régulation Spatiale des Génomes, F-75015, Paris, France
| | - Romain Koszul
- Institut Pasteur, CNRS UMR3525, Unité Régulation Spatiale des Génomes, F-75015, Paris, France.
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Su L, Chen F, Yu H, Yan H, Zhao F, Fan C, Zhao Y. Addition-Elimination Mechanism-Activated Nucleotide Transition Sequencing for RNA Dynamics Profiling. Anal Chem 2021; 93:13974-13980. [PMID: 34612623 DOI: 10.1021/acs.analchem.1c03361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Dynamic information of intracellular transcripts is essential to understand their functional roles. Routine RNA-sequencing (RNA-seq) methods only measure RNA species at a steady state and do not provide RNA dynamic information. Here, we develop addition-elimination mechanism-activated nucleotide transition sequencing (AENT-seq) for transcriptome-wide profiling of RNA dynamics. In AENT-seq, nascent transcripts are metabolically labeled with 4-thiouridine (4sU). The total RNA is treated with N2H4·H2O under aqueous conditions. N2H4·H2O is demonstrated to convert 4sU to 4-hydrazino cytosine (C*) based on an addition-elimination chemistry. C* is regarded as cytosine (C) during the DNA extension process. This 4sU-to-C transition marks nascent transcripts, so it enables sequencing analysis of RNA dynamics. We apply our AENT-seq to investigate transcript dynamic information of several genes involved in cancer progression and metastasis. This method uses a simple chemical reaction in aqueous solutions and will be rapidly disseminated with extensive applications.
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Affiliation(s)
- Li Su
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xianning West Road, Xi'an, Shaanxi 710049, China
| | - Feng Chen
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xianning West Road, Xi'an, Shaanxi 710049, China
| | - Huahang Yu
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xianning West Road, Xi'an, Shaanxi 710049, China
| | - Hao Yan
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xianning West Road, Xi'an, Shaanxi 710049, China
| | - Fengjiao Zhao
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xianning West Road, Xi'an, Shaanxi 710049, China
| | - Chunhai Fan
- Institute of Molecular Medicine, Renji Hospital, School of Medicine and School of Chemistry and Chemical Engineering, Shanghai JiaoTong University, Shanghai 200127, China
| | - Yongxi Zhao
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xianning West Road, Xi'an, Shaanxi 710049, China
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37
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Perea-Resa C, Wattendorf L, Marzouk S, Blower MD. Cohesin: behind dynamic genome topology and gene expression reprogramming. Trends Cell Biol 2021; 31:760-773. [PMID: 33766521 PMCID: PMC8364472 DOI: 10.1016/j.tcb.2021.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/23/2021] [Accepted: 03/04/2021] [Indexed: 01/01/2023]
Abstract
Beyond its originally discovered role tethering replicated sister chromatids, cohesin has emerged as a master regulator of gene expression. Recent advances in chromatin topology resolution and single-cell studies have revealed that cohesin has a pivotal role regulating highly dynamic chromatin interactions linked to transcription control. The dynamic association of cohesin with chromatin and its capacity to perform loop extrusion contribute to the heterogeneity of chromatin contacts. Additionally, different cohesin subcomplexes, with specific properties and regulation, control gene expression across the cell cycle and during developmental cell commitment. Here, we discuss the most recent literature in the field to highlight the role of cohesin in gene expression regulation during transcriptional shifts and its relationship with human diseases.
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Affiliation(s)
- Carlos Perea-Resa
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA.
| | - Lauren Wattendorf
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Sammer Marzouk
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Michael D Blower
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA.
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38
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Jerkovic I, Cavalli G. Understanding 3D genome organization by multidisciplinary methods. Nat Rev Mol Cell Biol 2021; 22:511-528. [PMID: 33953379 DOI: 10.1038/s41580-021-00362-w] [Citation(s) in RCA: 160] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/16/2021] [Indexed: 02/03/2023]
Abstract
Understanding how chromatin is folded in the nucleus is fundamental to understanding its function. Although 3D genome organization has been historically difficult to study owing to a lack of relevant methodologies, major technological breakthroughs in genome-wide mapping of chromatin contacts and advances in imaging technologies in the twenty-first century considerably improved our understanding of chromosome conformation and nuclear architecture. In this Review, we discuss methods of 3D genome organization analysis, including sequencing-based techniques, such as Hi-C and its derivatives, Micro-C, DamID and others; microscopy-based techniques, such as super-resolution imaging coupled with fluorescence in situ hybridization (FISH), multiplex FISH, in situ genome sequencing and live microscopy methods; and computational and modelling approaches. We describe the most commonly used techniques and their contribution to our current knowledge of nuclear architecture and, finally, we provide a perspective on up-and-coming methods that open possibilities for future major discoveries.
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Affiliation(s)
- Ivana Jerkovic
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France
| | - Giacomo Cavalli
- Institute of Human Genetics, CNRS, University of Montpellier, Montpellier, France.
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39
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Savocco J, Piazza A. Recombination-mediated genome rearrangements. Curr Opin Genet Dev 2021; 71:63-71. [PMID: 34325160 DOI: 10.1016/j.gde.2021.06.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/20/2021] [Accepted: 06/29/2021] [Indexed: 12/14/2022]
Abstract
Homologous recombination (HR) is a universal DNA double-strand break (DSB) repair pathway that uses an intact DNA molecule as a template. Signature HR reactions are homology search and DNA strand invasion catalyzed by the prototypical RecA-ssDNA filament (Rad51 and Dmc1 in eukaryotes), which produces heteroduplex DNA-containing joint molecules (JMs). These reactions uniquely infringe on the DNA strands association established at replication, on the basis of substantial sequence similarity. For that reason, and despite the high fidelity of its templated nature, DSB repair by HR authorizes the alteration of genome structure, guided by repetitive DNA elements. The resulting structural variations (SVs) can involve vast genomic regions, potentially affecting multiple coding sequences and regulatory elements at once, with possible pathological consequences. Here, we discuss recent advances in our understanding of genetic and molecular vulnerabilities of HR leading to SVs, and of the various fidelity-enforcing factors acting across scales on the balancing act of this complex pathway. An emphasis is put on extra-chomosomal DNAs, both product of, and substrate for HR-mediated chromosomal rearrangements.
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Affiliation(s)
- Jérôme Savocco
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, Lyon, France
| | - Aurèle Piazza
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR5239, Laboratoire de Biologie et Modélisation de la Cellule, Lyon, France.
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40
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Davidson IF, Peters JM. Genome folding through loop extrusion by SMC complexes. Nat Rev Mol Cell Biol 2021; 22:445-464. [PMID: 33767413 DOI: 10.1038/s41580-021-00349-7] [Citation(s) in RCA: 218] [Impact Index Per Article: 72.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2021] [Indexed: 02/02/2023]
Abstract
Genomic DNA is folded into loops and topologically associating domains (TADs), which serve important structural and regulatory roles. It has been proposed that these genomic structures are formed by a loop extrusion process, which is mediated by structural maintenance of chromosomes (SMC) protein complexes. Recent single-molecule studies have shown that the SMC complexes condensin and cohesin are indeed able to extrude DNA into loops. In this Review, we discuss how the loop extrusion hypothesis can explain key features of genome architecture; cellular functions of loop extrusion, such as separation of replicated DNA molecules, facilitation of enhancer-promoter interactions and immunoglobulin gene recombination; and what is known about the mechanism of loop extrusion and its regulation, for example, by chromatin boundaries that depend on the DNA binding protein CTCF. We also discuss how the loop extrusion hypothesis has led to a paradigm shift in our understanding of both genome architecture and the functions of SMC complexes.
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Affiliation(s)
- Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria.
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41
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Wang W, Klein KN, Proesmans K, Yang H, Marchal C, Zhu X, Borrman T, Hastie A, Weng Z, Bechhoefer J, Chen CL, Gilbert DM, Rhind N. Genome-wide mapping of human DNA replication by optical replication mapping supports a stochastic model of eukaryotic replication. Mol Cell 2021; 81:2975-2988.e6. [PMID: 34157308 DOI: 10.1016/j.molcel.2021.05.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 03/08/2021] [Accepted: 05/20/2021] [Indexed: 12/27/2022]
Abstract
The heterogeneous nature of eukaryotic replication kinetics and the low efficiency of individual initiation sites make mapping the location and timing of replication initiation in human cells difficult. To address this challenge, we have developed optical replication mapping (ORM), a high-throughput single-molecule approach, and used it to map early-initiation events in human cells. The single-molecule nature of our data and a total of >2,500-fold coverage of the human genome on 27 million fibers averaging ∼300 kb in length allow us to identify initiation sites and their firing probability with high confidence. We find that the distribution of human replication initiation is consistent with inefficient, stochastic activation of heterogeneously distributed potential initiation complexes enriched in accessible chromatin. These observations are consistent with stochastic models of initiation-timing regulation and suggest that stochastic regulation of replication kinetics is a fundamental feature of eukaryotic replication, conserved from yeast to humans.
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Affiliation(s)
- Weitao Wang
- Institut Curie, PSL Research University, CNRS UMR 3244, Paris 75005, France
| | - Kyle N Klein
- Florida State University, Department of Biological Science, Tallahassee, FL 32306, USA
| | - Karel Proesmans
- Simon Fraser University, Department of Physics, Burnaby, BC V5A 1S6, Canada
| | - Hongbo Yang
- Northwestern University, Feinberg School of Medicine, Department of Biochemistry and Molecular Genetics, Chicago, IL 60208, USA
| | - Claire Marchal
- Florida State University, Department of Biological Science, Tallahassee, FL 32306, USA
| | - Xiaopeng Zhu
- Carnegie Mellon University, Computational Biology Department, Pittsburgh, PA 15213, USA
| | - Tyler Borrman
- University of Massachusetts Medical School, Program in Bioinformatics and Integrated Biology, Worcester, MA 01605, USA
| | | | - Zhiping Weng
- University of Massachusetts Medical School, Program in Bioinformatics and Integrated Biology, Worcester, MA 01605, USA
| | - John Bechhoefer
- Simon Fraser University, Department of Physics, Burnaby, BC V5A 1S6, Canada.
| | - Chun-Long Chen
- Institut Curie, PSL Research University, CNRS UMR 3244, Paris 75005, France; Sorbonne University, Paris 75005, France.
| | - David M Gilbert
- Florida State University, Department of Biological Science, Tallahassee, FL 32306, USA.
| | - Nicholas Rhind
- University of Massachusetts Medical School, Department of Biochemistry and Molecular Pharmacology, Worcester, MA 01605, USA.
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42
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Li J, Lin Y, Tang Q, Li M. Understanding three-dimensional chromatin organization in diploid genomes. Comput Struct Biotechnol J 2021; 19:3589-3598. [PMID: 34257838 PMCID: PMC8246089 DOI: 10.1016/j.csbj.2021.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/11/2021] [Accepted: 06/12/2021] [Indexed: 11/17/2022] Open
Abstract
The three-dimensional (3D) organization of chromatin in the nucleus of diploid eukaryotic organisms has fascinated biologists for many years. Despite major progress in chromatin conformation studies, current knowledge regarding the spatial organization of diploid (maternal and paternal) genomes is still limited. Recent advances in Hi-C technology and data processing approaches have enabled construction of diploid Hi-C contact maps. These maps greatly accelerated the pace of novel discoveries in haplotype-resolved 3D genome studies, revealing the role of allele biased chromatin conformation in transcriptional regulation. Here, we review emerging concepts and haplotype phasing strategies of Hi-C data in 3D diploid genome studies. We discuss new insights on homologous chromosomal organization and the interplay between allelic biased chromatin architecture and several nuclear functions, explaining how haplotype-resolved Hi-C technologies have been used to resolve important biological questions.
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Affiliation(s)
- Jing Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Yu Lin
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Qianzi Tang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
| | - Mingzhou Li
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China
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43
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van Ruiten MS, Rowland BD. On the choreography of genome folding: A grand pas de deux of cohesin and CTCF. Curr Opin Cell Biol 2021; 70:84-90. [PMID: 33545664 DOI: 10.1016/j.ceb.2020.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 12/05/2020] [Indexed: 02/06/2023]
Abstract
Cohesin and CTCF are key to the 3D folding of interphase chromosomes. Cohesin forms chromatin loops via loop extrusion, a process that involves the formation and enlargement of DNA loops. The architectural protein CTCF controls this process by acting as an anchor for chromatin looping. How CTCF controls cohesin has long been a mystery. Recent work shows that CTCF dictates chromatin looping via a direct interaction of its N-terminus with cohesin. CTCF's ability to regulate chromatin looping turns out to also be partially dependent on several RNA-binding domains. In this review, we discuss recent insights and consider how cohesin and CTCF together may orchestrate the folding of the genome into chromosomal loops.
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Affiliation(s)
- Marjon S van Ruiten
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, 1066 CX, the Netherlands
| | - Benjamin D Rowland
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, 1066 CX, the Netherlands.
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44
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Peters JM. How DNA loop extrusion mediated by cohesin enables V(D)J recombination. Curr Opin Cell Biol 2021; 70:75-83. [PMID: 33422934 DOI: 10.1016/j.ceb.2020.11.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 11/28/2020] [Indexed: 12/16/2022]
Abstract
'Structural maintenance of chromosomes' (SMC) complexes are required for the folding of genomic DNA into loops. Theoretical considerations and single-molecule experiments performed with the SMC complexes cohesin and condensin indicate that DNA folding occurs via loop extrusion. Recent work indicates that this process is essential for the assembly of antigen receptor genes by V(D)J recombination in developing B and T cells of the vertebrate immune system. Here, I review how recent studies of the mouse immunoglobulin heavy chain locus Igh have provided evidence for this hypothesis and how the formation of chromatin loops by cohesin and regulation of this process by CTCF and Wapl might ensure that all variable gene segments in this locus (VH segments) participate in recombination with a re-arranged DJH segment, to ensure generation of a maximally diverse repertoire of B-cell receptors and antibodies.
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Affiliation(s)
- Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
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45
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Paulson JR, Hudson DF, Cisneros-Soberanis F, Earnshaw WC. Mitotic chromosomes. Semin Cell Dev Biol 2021; 117:7-29. [PMID: 33836947 PMCID: PMC8406421 DOI: 10.1016/j.semcdb.2021.03.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 01/25/2023]
Abstract
Our understanding of the structure and function of mitotic chromosomes has come a long way since these iconic objects were first recognized more than 140 years ago, though many details remain to be elucidated. In this chapter, we start with the early history of chromosome studies and then describe the path that led to our current understanding of the formation and structure of mitotic chromosomes. We also discuss some of the remaining questions. It is now well established that each mitotic chromatid consists of a central organizing region containing a so-called "chromosome scaffold" from which loops of DNA project radially. Only a few key non-histone proteins and protein complexes are required to form the chromosome: topoisomerase IIα, cohesin, condensin I and condensin II, and the chromokinesin KIF4A. These proteins are concentrated along the axis of the chromatid. Condensins I and II are primarily responsible for shaping the chromosome and the scaffold, and they produce the loops of DNA by an ATP-dependent process known as loop extrusion. Modelling of Hi-C data suggests that condensin II adopts a spiral staircase arrangement with an extruded loop extending out from each step in a roughly helical pattern. Condensin I then forms loops nested within these larger condensin II loops, thereby giving rise to the final compaction of the mitotic chromosome in a process that requires Topo IIα.
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Affiliation(s)
- James R Paulson
- Department of Chemistry, University of Wisconsin Oshkosh, 800 Algoma Boulevard, Oshkosh, WI 54901, USA.
| | - Damien F Hudson
- Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Fernanda Cisneros-Soberanis
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, ICB, University of Edinburgh, Michael Swann Building, King's Buildings, Max Born Crescent, Edinburgh EH9 3BF, Scotland, UK.
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46
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Krasheninina OA, Thaler J, Erlacher MD, Micura R. Amine-to-Azide Conversion on Native RNA via Metal-Free Diazotransfer Opens New Avenues for RNA Manipulations. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 133:7046-7050. [PMID: 38504956 PMCID: PMC10947191 DOI: 10.1002/ange.202015034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/19/2020] [Indexed: 03/21/2024]
Abstract
A major challenge in the field of RNA chemistry is the identification of selective and quantitative conversion reactions on RNA that can be used for tagging and any other RNA tool development. Here, we introduce metal-free diazotransfer on native RNA containing an aliphatic primary amino group using the diazotizing reagent fluorosulfuryl azide (FSO2N3). The reaction provides the corresponding azide-modified RNA in nearly quantitatively yields without affecting the nucleobase amino groups. The obtained azido-RNA can then be further processed utilizing well-established bioortho-gonal reactions, such as azide-alkyne cycloadditions (Click) or Staudinger ligations. We exemplify the robustness of this approach for the synthesis of peptidyl-tRNA mimics and for the pull-down of 3-(3-amino-3-carboxypropyl)uridine (acp3U)- and lysidine (k2C)-containing tRNAs of an Escherichia coli tRNA pool isolated from cellular extracts. Our approach therefore adds a new dimension to the targeted chemical manipulation of diverse RNA species.
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Affiliation(s)
- Olga A. Krasheninina
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Julia Thaler
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Matthias D. Erlacher
- Institute of Genomics and RNomicsBiocenterMedical University of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
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47
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Krasheninina OA, Thaler J, Erlacher MD, Micura R. Amine-to-Azide Conversion on Native RNA via Metal-Free Diazotransfer Opens New Avenues for RNA Manipulations. Angew Chem Int Ed Engl 2021; 60:6970-6974. [PMID: 33400347 PMCID: PMC8048507 DOI: 10.1002/anie.202015034] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/19/2020] [Indexed: 12/12/2022]
Abstract
A major challenge in the field of RNA chemistry is the identification of selective and quantitative conversion reactions on RNA that can be used for tagging and any other RNA tool development. Here, we introduce metal-free diazotransfer on native RNA containing an aliphatic primary amino group using the diazotizing reagent fluorosulfuryl azide (FSO2 N3 ). The reaction provides the corresponding azide-modified RNA in nearly quantitatively yields without affecting the nucleobase amino groups. The obtained azido-RNA can then be further processed utilizing well-established bioortho-gonal reactions, such as azide-alkyne cycloadditions (Click) or Staudinger ligations. We exemplify the robustness of this approach for the synthesis of peptidyl-tRNA mimics and for the pull-down of 3-(3-amino-3-carboxypropyl)uridine (acp3 U)- and lysidine (k2 C)-containing tRNAs of an Escherichia coli tRNA pool isolated from cellular extracts. Our approach therefore adds a new dimension to the targeted chemical manipulation of diverse RNA species.
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Affiliation(s)
- Olga A. Krasheninina
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Julia Thaler
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Matthias D. Erlacher
- Institute of Genomics and RNomicsBiocenterMedical University of InnsbruckInnrain 80–826020InnsbruckAustria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular BiosciencesUniversity of InnsbruckInnrain 80–826020InnsbruckAustria
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48
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Gregan J. The Spatial Organization of Sister Chromatids. Trends Biochem Sci 2021; 46:255-257. [PMID: 33593592 DOI: 10.1016/j.tibs.2021.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 11/19/2022]
Abstract
Understanding how genomes are spatially organized is central to many aspects of cell biology. However, it has been difficult to study the relationships between sister chromatids because sequencing-based techniques such as Hi-C could not distinguish identical sister DNAs. Here, I discuss recent developments that provide insights into sister chromatid organization.
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Affiliation(s)
- Juraj Gregan
- Advanced Microscopy Facility, VBCF, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, 1030 Vienna, Austria; Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, 1030 Vienna, Austria.
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49
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Mitter M, Gerlich DW. Mapping Sister Chromatid Conformation in Replicated Chromosomes. Trends Biochem Sci 2020; 46:169-170. [PMID: 33342665 DOI: 10.1016/j.tibs.2020.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 11/30/2020] [Indexed: 12/24/2022]
Affiliation(s)
- Michael Mitter
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria.
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50
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Detecting chromatin interactions between and along sister chromatids with SisterC. Nat Methods 2020; 17:1002-1009. [PMID: 32968250 PMCID: PMC7541687 DOI: 10.1038/s41592-020-0930-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 07/04/2020] [Accepted: 07/21/2020] [Indexed: 11/28/2022]
Abstract
Chromosome segregation requires both compaction and disentanglement of sister chromatids. We describe SisterC, a chromosome conformation capture assay that distinguishes interactions between and along identical sister chromatids. SisterC employs BrdU incorporation during S-phase to label newly replicated strands, followed by Hi-C and then the destruction of BrdU-containing strands by UV/Hoechst treatment. After sequencing of the remaining intact strands, this allows for assignment of Hi-C products as inter- and intra-sister interactions based on the strands that reads are mapped to. We performed SisterC on mitotic S. cerevisiae cells. We find precise alignment of sister chromatids at centromeres. Along arms, sister chromatids are less precisely aligned with inter-sister connections every ~35kb. Inter-sister interactions occur between cohesin binding sites that often are offset by 5 to 25kb. Along sister chromatids, cohesin forms loops of up to 50kb. SisterC allows study of the complex interplay between sister chromatid compaction and their segregation during mitosis.
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