1
|
Hirano T. Mitotic genome folding. J Cell Biol 2025; 224:e202504075. [PMID: 40492990 DOI: 10.1083/jcb.202504075] [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: 04/14/2025] [Revised: 05/30/2025] [Accepted: 06/02/2025] [Indexed: 06/12/2025] Open
Abstract
Mitotic genome folding, or mitotic chromosome assembly, is essential for the faithful segregation of genetic information into daughter cells. While this process was once thought to be highly complex, requiring a myriad of protein components, recent studies have begun to revise this conventional view. An emerging view is that the core reaction of mitotic genome folding is mediated by a dynamic interplay of a limited number of structural components, namely, condensins, topoisomerase II (topo II), and histones. Condensins and topo II are two distinct classes of ATPases that cooperate to actively form and manipulate DNA loops, both accumulating at the central axial regions of the resulting chromosomes. In contrast, nucleosomes and linker histones help to compact DNA loops by cooperating and competing with the action of these ATPases. In this review, I will focus on the recent advances in the field, with an emphasis on the mechanistic aspects of mitotic genome folding.
Collapse
|
2
|
Fettweis G, Wagh K, Stavreva DA, Jiménez-Panizo A, Kim S, Lion M, Alegre-Martí A, Rinaldi L, Johnson TA, Gilson E, Krishnamurthy M, Wang L, Ball DA, Karpova TS, Upadhyaya A, Vertommen D, Recio JF, Estébanez-Perpiñá E, Dequiedt F, Hager GL. Transcription factors form a ternary complex with NIPBL/MAU2 to localize cohesin at enhancers. Nucleic Acids Res 2025; 53:gkaf415. [PMID: 40377219 DOI: 10.1093/nar/gkaf415] [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: 02/18/2025] [Revised: 04/14/2025] [Accepted: 05/06/2025] [Indexed: 05/18/2025] Open
Abstract
While the cohesin complex is a key player in genome architecture, how it localizes to specific chromatin sites is not understood. Recently, we and others have proposed that direct interactions with transcription factors lead to the localization of the cohesin-loader complex (NIPBL/MAU2) within enhancers. Here, we identify two clusters of LxxLL motifs within the NIPBL sequence that regulate NIPBL dynamics, interactome, and NIPBL-dependent transcriptional programs. One of these clusters interacts with MAU2 and is necessary for the maintenance of the NIPBL-MAU2 heterodimer. The second cluster binds specifically to the ligand-binding domains of steroid receptors. For the glucocorticoid receptor (GR), we examine in detail its interaction surfaces with NIPBL and MAU2. Using AlphaFold2 and molecular docking algorithms, we uncover a GR-NIPBL-MAU2 ternary complex and describe its importance in GR-dependent gene regulation. Finally, we show that multiple transcription factors interact with NIPBL-MAU2, likely using interfaces other than those characterized for GR.
Collapse
Affiliation(s)
- Gregory Fettweis
- Laboratory of Gene Expression and Cancer, GIGA-Molecular & Computational Biology, University of Liège, 4000 Liège, Belgium
| | - Kaustubh Wagh
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Diana A Stavreva
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Alba Jiménez-Panizo
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
- Instituto de Ciencias de la Vid y del Vino (ICVV), CSIC-Universidad de La Rioja-Gobierno de La Rioja, 26007 Logroño, Spain
| | - Sohyoung Kim
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Michelle Lion
- Laboratory of Gene Expression and Cancer, GIGA-Molecular & Computational Biology, University of Liège, 4000 Liège, Belgium
| | - Andrea Alegre-Martí
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona (UB), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona (UB), 08028 Barcelona, Spain
| | - Lorenzo Rinaldi
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Thomas A Johnson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Elise Gilson
- Laboratory of Gene Expression and Cancer, GIGA-Molecular & Computational Biology, University of Liège, 4000 Liège, Belgium
| | - Manan Krishnamurthy
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Li Wang
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - David A Ball
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Tatiana S Karpova
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, MD 20742, United States
- Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, United States
| | - Didier Vertommen
- de Duve Institute, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Juan Fernández Recio
- Instituto de Ciencias de la Vid y del Vino (ICVV), CSIC-Universidad de La Rioja-Gobierno de La Rioja, 26007 Logroño, Spain
| | - Eva Estébanez-Perpiñá
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona (UB), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona (UB), 08028 Barcelona, Spain
| | - Franck Dequiedt
- Laboratory of Gene Expression and Cancer, GIGA-Molecular & Computational Biology, University of Liège, 4000 Liège, Belgium
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-5055, United States
| |
Collapse
|
3
|
Chen L, Zhang Z, Wang Z, Hong L, Wang H, Zhang J. Barrier effects on the kinetics of cohesin-mediated loop extrusion. Biophys J 2025; 124:1462-1477. [PMID: 40181539 DOI: 10.1016/j.bpj.2025.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2024] [Revised: 01/23/2025] [Accepted: 03/26/2025] [Indexed: 04/05/2025] Open
Abstract
Chromosome organization mediated by structural maintenance of chromosome complexes is crucial in many organisms. Cohesin extrudes chromatin into loops that are thought to lengthen until it is obstructed by CTCF proteins. In complex cellular environments, the loop extrusion machinery may encounter other chromatin-binding proteins. How these proteins interfere with the cohesin-meditated extrusion process is largely unexplored, but recent experiments have shown that some proteins serve as physical barriers that block cohesin translocation. Other proteins containing a cohesin-interaction motif serve as chemical barriers to induce cohesin pausing through interactions with it. Here, we develop an analytically solvable approach for the loop extrusion model incorporating barriers to investigate the effect of the barrier on the passive extrusion process. To further quantify the impact of barriers, we calculate the mean looping time it takes for cohesin to translocate to form a stable loop before dissociation. Our finding reveals that the physical barrier can accelerate the loop formation, and the degree of acceleration is closely related to the impedance strength of the physical barrier. In particular, the synergy of the cohesin loading site and the physical barrier site accelerates loop formation more significantly. The proximity of the cohesin loading site to the barrier site facilitates the rapid formation of stable loops in long genomes, which implies loop extrusion and chromatin-binding proteins might shape functional genomic organization. Conversely, chemical barriers consistently impede loop formation, with increasing impedance strength of the chemical barrier leading to longer loop formation time. Our study contributes to a more comprehensive understanding of the complexity of the loop extrusion process, providing a new perspective on the potential mechanisms of gene regulation.
Collapse
Affiliation(s)
- Leiyan Chen
- Guangdong Province Key Laboratory of Computational Science, Sun Yat-sen University, Guangzhou 510275, P.R. China; School of Mathematics, Sun Yat-sen University, Guangzhou 510275, P.R. China
| | - Zhenquan Zhang
- Guangdong Province Key Laboratory of Computational Science, Sun Yat-sen University, Guangzhou 510275, P.R. China; School of Mathematics, Sun Yat-sen University, Guangzhou 510275, P.R. China
| | - Zihao Wang
- Guangdong Province Key Laboratory of Computational Science, Sun Yat-sen University, Guangzhou 510275, P.R. China; School of Mathematics, Sun Yat-sen University, Guangzhou 510275, P.R. China
| | - Liu Hong
- School of Mathematics, Sun Yat-sen University, Guangzhou 510275, P.R. China
| | - Haohua Wang
- School of Mathematics and Statistics, Hainan University, Haikou 570228, P.R. China.
| | - Jiajun Zhang
- Guangdong Province Key Laboratory of Computational Science, Sun Yat-sen University, Guangzhou 510275, P.R. China; School of Mathematics, Sun Yat-sen University, Guangzhou 510275, P.R. China.
| |
Collapse
|
4
|
Koide H, Kodera N, Takada S, Terakawa T. Solution AFM Imaging and Coarse-grained Molecular Modeling of Yeast Condensin Structural Variation Coupled to the ATP Hydrolysis Cycle. J Mol Biol 2025; 437:169185. [PMID: 40324744 DOI: 10.1016/j.jmb.2025.169185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2025] [Revised: 04/25/2025] [Accepted: 04/29/2025] [Indexed: 05/07/2025]
Abstract
Condensin is a protein complex that regulates chromatin structural changes during mitosis. It varies the molecular conformation through the ATP hydrolysis cycle and extrudes DNA loops into its ring-like structure as a molecular motor. Condensin contains Smc2 and Smc4, in which a coiled-coil arm tethers the hinge and head domains and dimerizes at the hinge. ATPs bind between the heads, induce their engagement, and are hydrolyzed to promote their disengagement. Previously, we performed solution atomic force microscopy (AFM) imaging of yeast condensin holo-complex with ATP and conducted flexible molecular fitting, obtaining the hinge structure with open conformation. However, it has yet to be clarified how the opening/closing of the hinge is coupled to the ATP hydrolysis cycle. In this study, we performed solution AFM imaging in the presence and absence of varying nucleotides, including AMP-PNP, ATPγS, and ADP. Furthermore, we conducted molecular dynamics simulations of an Smc2/4 heterodimer and selected the structure best representing each AFM image. Our results suggested that head engagement upon ATP binding is coupled to hinge opening and that the N-terminal region of Brn1, one of the accessory subunits, re-associates to the Smc2 head after ADP release.
Collapse
Affiliation(s)
- Hiroki Koide
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Noriyuki Kodera
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Tsuyoshi Terakawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
| |
Collapse
|
5
|
Bürmann F, Clifton B, Koekemoer S, Wilkinson OJ, Kimanius D, Dillingham MS, Löwe J. Mechanism of DNA capture by the MukBEF SMC complex and its inhibition by a viral DNA mimic. Cell 2025; 188:2465-2479.e14. [PMID: 40168993 DOI: 10.1016/j.cell.2025.02.032] [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: 10/16/2024] [Revised: 12/18/2024] [Accepted: 02/26/2025] [Indexed: 04/03/2025]
Abstract
Ring-like structural maintenance of chromosome (SMC) complexes are crucial for genome organization and operate through mechanisms of DNA entrapment and loop extrusion. Here, we explore the DNA loading process of the bacterial SMC complex MukBEF. Using cryoelectron microscopy (cryo-EM), we demonstrate that ATP binding opens one of MukBEF's three potential DNA entry gates, exposing a DNA capture site that positions DNA at the open neck gate. We discover that the gp5.9 protein of bacteriophage T7 blocks this capture site by DNA mimicry, thereby preventing DNA loading and inactivating MukBEF. We propose a comprehensive and unidirectional loading mechanism in which DNA is first captured at the complex's periphery and then ingested through the DNA entry gate, powered by a single cycle of ATP hydrolysis. These findings illuminate a fundamental aspect of how ubiquitous DNA organizers are primed for genome maintenance and demonstrate how this process can be disrupted by viruses.
Collapse
Affiliation(s)
- Frank Bürmann
- MRC Laboratory of Molecular Biology, Structural Studies, Francis Crick Avenue, Cambridge CB2 0QH, UK; University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK.
| | - Bryony Clifton
- University of Bristol, School of Biochemistry, DNA:Protein Interactions Unit, Bristol BS8 1TD, UK
| | - Sophie Koekemoer
- University of Bristol, School of Biochemistry, DNA:Protein Interactions Unit, Bristol BS8 1TD, UK
| | - Oliver J Wilkinson
- University of Bristol, School of Biochemistry, DNA:Protein Interactions Unit, Bristol BS8 1TD, UK
| | - Dari Kimanius
- MRC Laboratory of Molecular Biology, Structural Studies, Francis Crick Avenue, Cambridge CB2 0QH, UK; CZ Imaging Institute, 3400 Bridge Parkway, Redwood City, CA 94065, USA
| | - Mark S Dillingham
- University of Bristol, School of Biochemistry, DNA:Protein Interactions Unit, Bristol BS8 1TD, UK.
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Structural Studies, Francis Crick Avenue, Cambridge CB2 0QH, UK.
| |
Collapse
|
6
|
Samejima K, Gibcus JH, Abraham S, Cisneros-Soberanis F, Samejima I, Beckett AJ, Pučeková N, Abad MA, Spanos C, Medina-Pritchard B, Paulson JR, Xie L, Jeyaprakash AA, Prior IA, Mirny LA, Dekker J, Goloborodko A, Earnshaw WC. Rules of engagement for condensins and cohesins guide mitotic chromosome formation. Science 2025; 388:eadq1709. [PMID: 40208986 PMCID: PMC12118822 DOI: 10.1126/science.adq1709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 12/25/2024] [Indexed: 04/12/2025]
Abstract
We used Hi-C, imaging, proteomics, and polymer modeling to define rules of engagement for SMC (structural maintenance of chromosomes) complexes as cells refold interphase chromatin into rod-shaped mitotic chromosomes. First, condensin disassembles interphase chromatin loop organization by evicting or displacing extrusive cohesin. Second, condensin bypasses cohesive cohesins, thereby maintaining sister chromatid cohesion as sisters separate. Studies of mitotic chromosomes formed by cohesin, condensin II, and condensin I alone or in combination lead to refined models of mitotic chromosome conformation. In these models, loops are consecutive and not overlapping, implying that condensins stall upon encountering each other. The dynamics of Hi-C interactions and chromosome morphology reveal that during prophase, loops are extruded in vivo at ∼1 to 3 kilobases per second by condensins as they form a disordered discontinuous helical scaffold within individual chromatids.
Collapse
Affiliation(s)
- Kumiko Samejima
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Johan H. Gibcus
- Department of Systems Biology, University of Massachusetts Chan Medical School; Worcester, USA
| | - Sameer Abraham
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology; Cambridge, USA
| | | | - Itaru Samejima
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Alison J. Beckett
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool; Liverpool, UK
| | - Nina Pučeková
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Maria Alba Abad
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Christos Spanos
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - Bethan Medina-Pritchard
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| | - James R. Paulson
- Department of Chemistry, University of Wisconsin-Oshkosh; Oshkosh, USA
| | - Linfeng Xie
- Department of Chemistry, University of Wisconsin-Oshkosh; Oshkosh, USA
| | - A. Arockia Jeyaprakash
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
- Gene Center Munich, Ludwig-Maximilians-Universität München; Munich, Germany
| | - Ian A. Prior
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool; Liverpool, UK
| | - Leonid A. Mirny
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology; Cambridge, USA
| | - Job Dekker
- Department of Systems Biology, University of Massachusetts Chan Medical School; Worcester, USA
- Howard Hughes Medical Institute; Chevy Chase, USA
| | | | - William C. Earnshaw
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh; Edinburgh, UK
| |
Collapse
|
7
|
Paldi F, Cavalli G. 3D genome folding in epigenetic regulation and cellular memory. Trends Cell Biol 2025:S0962-8924(25)00065-0. [PMID: 40221344 DOI: 10.1016/j.tcb.2025.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2025] [Revised: 03/07/2025] [Accepted: 03/11/2025] [Indexed: 04/14/2025]
Abstract
The 3D folding of the genome is tightly linked to its epigenetic state which maintains gene expression programmes. Although the relationship between gene expression and genome organisation is highly context dependent, 3D genome organisation is emerging as a novel epigenetic layer to reinforce and stabilise transcriptional states. Whether regulatory information carried in genome folding could be transmitted through mitosis is an area of active investigation. In this review, we discuss the relationship between epigenetic state and nuclear organisation, as well as the interplay between transcriptional regulation and epigenetic genome folding. We also consider the architectural remodelling of nuclei as cells enter and exit mitosis, and evaluate the potential of the 3D genome to contribute to cellular memory.
Collapse
Affiliation(s)
- Flora Paldi
- Institute of Human Genetics, CNRS and University of Montpellier, Montpellier, France
| | - Giacomo Cavalli
- Institute of Human Genetics, CNRS and University of Montpellier, Montpellier, France.
| |
Collapse
|
8
|
Fujishiro S, Sasai M, Maeshima K. Chromatin domains in the cell: Phase separation and condensation. Curr Opin Struct Biol 2025; 91:103006. [PMID: 39983411 DOI: 10.1016/j.sbi.2025.103006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2024] [Revised: 01/25/2025] [Accepted: 01/27/2025] [Indexed: 02/23/2025]
Abstract
Negatively charged genomic DNA wraps around positively charged core histone octamers to form nucleosomes, which, along with proteins and RNAs, self-organize into chromatin within the nucleus. In eukaryotic cells, chromatin forms loops that collapse into chromatin domains and serve as functional units of the genome. Chromatin domains vary in physical properties based on gene activity and are assembled into A (euchromatin) and B (heterochromatin) compartments. Since various factors-such as chromatin-binding proteins, histone modifications, transcriptional states, depletion attraction, and cations-can significantly impact chromatin organization, the formation processes of these hierarchical structures remain unclear. No single imaging, genomics, or modeling method can provide a complete picture of the process. Beautiful models can sometimes fool our thinking. In this short review, we critically discuss the formation mechanisms of the chromatin domain in the cell from a physical point of view, including phase separation and condensation.
Collapse
Affiliation(s)
- Shin Fujishiro
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto, 606-8103, Japan.
| | - Masaki Sasai
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto, 606-8103, Japan; Department of Complex Systems Science, Nagoya University, Nagoya, 464-8603, Japan.
| | - Kazuhiro Maeshima
- Genome Dynamics Laboratory, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan; Graduate Institute for Advanced Studies (SOKENDAI), Mishima, Shizuoka, 411-8540, Japan.
| |
Collapse
|
9
|
Zhao H, Shu L, Qin S, Lyu F, Liu F, Lin E, Xia S, Wang B, Wang M, Shan F, Lin Y, Zhang L, Gu Y, Blobel GA, Huang K, Zhang H. Extensive mutual influences of SMC complexes shape 3D genome folding. Nature 2025; 640:543-553. [PMID: 40011778 DOI: 10.1038/s41586-025-08638-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Accepted: 01/13/2025] [Indexed: 02/28/2025]
Abstract
Mammalian genomes are folded through the distinct actions of structural maintenance of chromosome (SMC) complexes, which include the chromatin loop-extruding cohesin (extrusive cohesin), the sister chromatid cohesive cohesin and the mitotic chromosome-associated condensins1-3. Although these complexes function at different stages of the cell cycle, they exist together on chromatin during the G2-to-M phase transition, when the genome structure undergoes substantial reorganization1,2. Yet, how the different SMC complexes affect each other and how their interactions orchestrate the dynamic folding of the three-dimensional genome remain unclear. Here we engineered all possible cohesin and condensin configurations on mitotic chromosomes to delineate the concerted, mutually influential action of SMC complexes. We show that condensin disrupts the binding of extrusive cohesin at CCCTC-binding factor (CTCF) sites, thereby promoting the disassembly of interphase topologically associating domains (TADs) and loops during mitotic progression. Conversely, extrusive cohesin impedes condensin-mediated mitotic chromosome spiralization. Condensin reduces peaks of cohesive cohesin, whereas cohesive cohesin antagonizes condensin-mediated longitudinal shortening of mitotic chromosomes. The presence of both extrusive and cohesive cohesin synergizes these effects and inhibits mitotic chromosome condensation. Extrusive cohesin positions cohesive cohesin at CTCF-binding sites. However, cohesive cohesin by itself cannot be arrested by CTCF molecules and is insufficient to establish TADs or loops. Moreover, it lacks loop-extrusion capacity, which indicates that cohesive cohesin has nonoverlapping functions with extrusive cohesin. Finally, cohesive cohesin restricts chromatin loop expansion mediated by extrusive cohesin. Collectively, our data describe a three-way interaction among major SMC complexes that dynamically modulates chromatin architecture during cell cycle progression.
Collapse
Affiliation(s)
- Han Zhao
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Lirong Shu
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- Shenzhen Medical Academy of Research and Translation, Shenzhen, China
| | - Shiyi Qin
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Fangxuan Lyu
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Fuhai Liu
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
| | - En Lin
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Sijian Xia
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- Capital Medical University, Beijing, China
| | - Baiyue Wang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Manzhu Wang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- Capital Medical University, Beijing, China
| | - Fengnian Shan
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- South China University of Technology, Guangzhou, China
| | - Yinzhi Lin
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- Shenzhen Medical Academy of Research and Translation, Shenzhen, China
| | - Lin Zhang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- School of Biological Science, Hong Kong University, Hong Kong, China
| | - Yufei Gu
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Gerd A Blobel
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kai Huang
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China.
| | - Haoyue Zhang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China.
| |
Collapse
|
10
|
Lee J, Chen LF, Gaudin S, Gupta K, Spakowitz A, Boettiger AN. Kinetic organization of the genome revealed by ultra-resolution, multiscale live imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.27.645817. [PMID: 40236138 PMCID: PMC11996339 DOI: 10.1101/2025.03.27.645817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2025]
Abstract
In the last decade, sequencing methods like Hi-C have made it clear the genome is intricately folded, and that this organization contributes significantly to the control of gene expression and thence cell fate and behavior. Single-cell DNA tracing microscopy and polymer physics-based simulations of genome folding have proposed these population-scale patterns arise from motor- driven, heterogeneous movement, rather than stable 3D genomic architecture, implying that motion, rather than structure, is key to understanding genome function. However, tools to directly observe this motion in vivo have been limited in coverage and resolution. Here we describe TRansposon Assisted Chromatin Kinetic Imaging Technology (TRACK-IT), which combines a suite of imaging and labeling improvements to achieve ultra-resolution in space and time, with self-mapping transposons to distribute labels across the chromosome, uncovering dynamic behaviors across four orders of magnitude of genomic separation. We find that sequences separated by sub-megabase distances, typically 200-500 nm of nanometers apart, can transition to close proximity in tens of seconds - faster than previously hypothesized. This rapid motion is dependent upon cohesin and is exhibited only within certain genomic domains. Domain borders act as kinetic impediments to this search process, substantially slowing the rate and frequency of the transition to proximity. The genomic separation-dependent scaling of the search time for cis-interactions within a domain violates predictions of diffusion, suggesting motor driven folding. This distinctive scaling is lost following cohesin depletion, replaced with a behavior consistent with diffusion. Finally, we found cohesin containing cells exhibited rare, processive movements, not seen in cohesin depleted cells. These processive trajectories exhibit extrusion rates of ∼2.7 kb/s across three distinct genomic intervals, faster than recent in vitro measurements and prior estimates from in vivo data. Taken together, these results reveal a genome in motion across multiple genomic and temporal scales, where motor-dependent extrusion divides the sequence, not into spatially separate domains, but into kinetically separated domains that experience accelerated local search.
Collapse
|
11
|
Qi S, Shi Z, Yu H. Genome folding by cohesin. Curr Opin Genet Dev 2025; 91:102310. [PMID: 39827577 DOI: 10.1016/j.gde.2025.102310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2024] [Revised: 12/22/2024] [Accepted: 01/03/2025] [Indexed: 01/22/2025]
Abstract
Chromosomes in eukaryotic cells undergo compaction at multiple levels and are folded into hierarchical structures to fit into the nucleus with limited dimensions. Three-dimensional genome organization needs to be coordinated with chromosome-templated processes, including DNA replication and gene transcription. As an ATPase molecular machine, the cohesin complex is a major driver of genome folding, which regulates transcription by modulating promoter-enhancer contacts. Here, we review our current understanding of genome folding by cohesin. We summarize the available evidence supporting a role of loop extrusion by cohesin in forming chromatin loops and topologically associating domains. We describe different conformations of cohesin and discuss the regulation of loop extrusion by cohesin-binding factors and loop-extrusion barriers. Finally, we propose a dimeric inchworm model for cohesin-mediated loop extrusion.
Collapse
Affiliation(s)
- Shutao Qi
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; New Cornerstone Science Laboratory, Westlake University, Hangzhou, Zhejiang, China
| | - Zhubing Shi
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China.
| | - Hongtao Yu
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China; New Cornerstone Science Laboratory, Westlake University, Hangzhou, Zhejiang, China.
| |
Collapse
|
12
|
Rodemoyer B, Kariyawasam G, Subramanian V, Schmidt K. Condensin II interacts with BLM helicase in S phase to maintain genome stability. Commun Biol 2025; 8:492. [PMID: 40133469 PMCID: PMC11937517 DOI: 10.1038/s42003-025-07916-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Accepted: 03/11/2025] [Indexed: 03/27/2025] Open
Abstract
Vertebrates possess two condensins, I and II, that are essential for chromosome condensation and segregation. Condensin II has also been implicated in maintaining genome integrity outside of mitosis, though the underlying mechanisms are unclear. Here, we found that condensin II interacts with a short linear motif in the disordered N-terminal tail of the Bloom syndrome helicase BLM, contributing to BLM association with nascent DNA and genome stability. Disrupting the BLM-condensin II interaction reduced replication speed, increased fork stalling and sister-chromatid exchanges, delayed repair of DNA double-strand breaks, and led to micronuclei. In S phase, interactions of SMC2 with other condensin II subunits and with BLM weakened temporarily, suggesting a conformational change followed by phosphorylation-induced disruption of BLM interactions with TOP2A and RPA. Our findings suggest a new way by which BLM contributes to genome integrity and implicates condensin II in interphase functions linked to genome stability.
Collapse
Affiliation(s)
- Brian Rodemoyer
- Department of Molecular Biosciences, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA
| | - Ganesha Kariyawasam
- Department of Molecular Biosciences, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA
| | - Veena Subramanian
- Department of Molecular Biosciences, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA
| | - Kristina Schmidt
- Department of Molecular Biosciences, University of South Florida, 4202 E. Fowler Ave., Tampa, FL, 33620, USA.
- Cancer Biology & Evolution Program, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA.
| |
Collapse
|
13
|
Uhlmann F. A unified model for cohesin function in sisterchromatid cohesion and chromatin loop formation. Mol Cell 2025; 85:1058-1071. [PMID: 40118039 DOI: 10.1016/j.molcel.2025.02.005] [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: 09/20/2024] [Revised: 01/12/2025] [Accepted: 02/06/2025] [Indexed: 03/23/2025]
Abstract
The ring-shaped cohesin complex topologically entraps two DNAs to establish sister chromatid cohesion. Cohesin also shapes the interphase chromatin landscape by forming DNA loops, which it is thought to achieve using an in vitro-observed loop extrusion mechanism. However, recent studies revealed that loop-extrusion-deficient cohesin retains its ability to form chromatin loops, suggesting a divergence of in vitro and in vivo loop formation. Instead of loop extrusion, we examine whether cohesin forms chromatin loops by a mechanism akin to sister chromatid cohesion establishment: sequential topological capture of two DNAs. We explore similarities and differences between the "loop capture" and the "loop extrusion" model, how they compare at explaining experimental observations, and how future approaches can delineate their possible respective contributions. We extend our DNA-DNA capture model for cohesin function to related structural maintenance of chromosomes (SMC) family members, condensin, the Smc5-Smc6 complex, and bacterial SMC complexes.
Collapse
Affiliation(s)
- Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
| |
Collapse
|
14
|
Liao Q, Brandão HB, Ren Z, Wang X. Replisomes restrict SMC-mediated DNA-loop extrusion in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.02.23.639750. [PMID: 40027636 PMCID: PMC11870623 DOI: 10.1101/2025.02.23.639750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2025]
Abstract
Structural maintenance of chromosomes (SMC) complexes organize genomes by extruding DNA loops, while replisomes duplicate entire chromosomes. These essential molecular machines must collide frequently in every cell cycle, yet how such collisions are resolved in vivo remains poorly understood. Taking advantage of the ability to load SMC complexes at defined sites in the Bacillus subtilis genome, we engineered head-on and head-to-tail collisions between SMC complexes and the replisome. Replisome progression was monitored by marker frequency analysis, and SMC translocation was monitored by time-resolved ChIP-seq and Hi-C. We found that SMC complexes do not impede replisome progression. By contrast, replisomes restrict SMC translocation regardless of collision orientations. Combining experimental data with simulations, we determined that SMC complexes are blocked by the replisome and then released from the chromosome. Occasionally, SMC complexes can bypass the replisome and continue translocating. Our findings establish that the replisome is a barrier to SMC-mediated DNA-loop extrusion in vivo , with implications for processes such as chromosome segregation, DNA repair, and gene regulation that require dynamic chromosome organization in all organisms.
Collapse
|
15
|
Selivanovskiy AV, Molodova MN, Khrameeva EE, Ulianov SV, Razin SV. Liquid condensates: a new barrier to loop extrusion? Cell Mol Life Sci 2025; 82:80. [PMID: 39976773 PMCID: PMC11842697 DOI: 10.1007/s00018-024-05559-8] [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: 07/10/2024] [Revised: 12/04/2024] [Accepted: 12/20/2024] [Indexed: 02/23/2025]
Abstract
Liquid-liquid phase separation (LLPS), driven by dynamic, low-affinity multivalent interactions of proteins and RNA, results in the formation of macromolecular condensates on chromatin. These structures are likely to provide high local concentrations of effector factors responsible for various processes including transcriptional regulation and DNA repair. In particular, enhancers, super-enhancers, and promoters serve as platforms for condensate assembly. In the current paradigm, enhancer-promoter (EP) interaction could be interpreted as a result of enhancer- and promoter-based condensate contact/fusion. There is increasing evidence that the spatial juxtaposition of enhancers and promoters could be provided by loop extrusion (LE) by SMC complexes. Here, we propose that condensates may act as barriers to LE, thereby contributing to various nuclear processes including spatial contacts between regulatory genomic elements.
Collapse
Affiliation(s)
- Arseniy V Selivanovskiy
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234, Moscow, Russia
| | - Maria N Molodova
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
- Skolkovo Institute of Science and Technology, 121205, Moscow, Russia
| | | | - Sergey V Ulianov
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234, Moscow, Russia
| | - Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, 119334, Moscow, Russia.
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234, Moscow, Russia.
| |
Collapse
|
16
|
Fettweis G, Wagh K, Stavreva DA, Jiménez-Panizo A, Kim S, Lion M, Alegre-Martí A, Rinaldi L, Johnson TA, Krishnamurthy M, Wang L, Ball DA, Karpova TS, Upadhyaya A, Vertommen D, Recio JF, Estébanez-Perpiñá E, Dequiedt F, Hager GL. Transcription factors form a ternary complex with NIPBL/MAU2 to localize cohesin at enhancers. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2024.12.09.627537. [PMID: 39713324 PMCID: PMC11661173 DOI: 10.1101/2024.12.09.627537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/24/2024]
Abstract
While the cohesin complex is a key player in genome architecture, how it localizes to specific chromatin sites is not understood. Recently, we and others have proposed that direct interactions with transcription factors lead to the localization of the cohesin-loader complex (NIPBL/MAU2) within enhancers. Here, we identify two clusters of LxxLL motifs within the NIPBL sequence that regulate NIPBL dynamics, interactome, and NIPBL-dependent transcriptional programs. One of these clusters interacts with MAU2 and is necessary for the maintenance of the NIPBL-MAU2 heterodimer. The second cluster binds specifically to the ligand-binding domains of steroid receptors. For the glucocorticoid receptor (GR), we examine in detail its interaction surfaces with NIPBL and MAU2. Using AlphaFold2 and molecular docking algorithms, we uncover a GR-NIPBL-MAU2 ternary complex and describe its importance in GR-dependent gene regulation. Finally, we show that multiple transcription factors interact with NIPBL-MAU2, likely using interfaces other than those characterized for GR.
Collapse
Affiliation(s)
- Gregory Fettweis
- Laboratory of Gene Expression and Cancer, GIGA-Molecular & Computational Biology, University of Liège, 4000 Liège, Belgium
| | - Kaustubh Wagh
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Diana A. Stavreva
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alba Jiménez-Panizo
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Instituto de Ciencias de la Vid y del Vino (ICVV), CSIC - Universidad de La Rioja - Gobierno de La Rioja, 26007 Logroño, Spain
| | - Sohyoung Kim
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michelle Lion
- Laboratory of Gene Expression and Cancer, GIGA-Molecular & Computational Biology, University of Liège, 4000 Liège, Belgium
| | - Andrea Alegre-Martí
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona (UB), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona (UB), 08028 Barcelona, Spain
| | - Lorenzo Rinaldi
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Present Address: Delfi Diagnostics Inc, Baltimore, MD 21224, USA
| | - Thomas A. Johnson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Manan Krishnamurthy
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Present Address: Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Li Wang
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David A. Ball
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tatiana S. Karpova
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, Maryland 20742, USA
- Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
| | - Didier Vertommen
- de Duve Institute, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Juan Fernández Recio
- Instituto de Ciencias de la Vid y del Vino (ICVV), CSIC - Universidad de La Rioja - Gobierno de La Rioja, 26007 Logroño, Spain
| | - Eva Estébanez-Perpiñá
- Institute of Biomedicine of the University of Barcelona (IBUB), University of Barcelona (UB), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona (UB), 08028 Barcelona, Spain
| | - Franck Dequiedt
- Laboratory of Gene Expression and Cancer, GIGA-Molecular & Computational Biology, University of Liège, 4000 Liège, Belgium
| | - Gordon L. Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
17
|
Barth R, Davidson IF, van der Torre J, Taschner M, Gruber S, Peters JM, Dekker C. SMC motor proteins extrude DNA asymmetrically and can switch directions. Cell 2025; 188:749-763.e21. [PMID: 39824185 DOI: 10.1016/j.cell.2024.12.020] [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: 12/22/2023] [Revised: 09/13/2024] [Accepted: 12/13/2024] [Indexed: 01/20/2025]
Abstract
Structural maintenance of chromosomes (SMC) complexes organize the genome via DNA loop extrusion. Although some SMCs were reported to do so symmetrically, reeling DNA from both sides into the extruded DNA loop simultaneously, others perform loop extrusion asymmetrically toward one direction only. The mechanism underlying this variability remains unclear. Here, we examine the directionality of DNA loop extrusion by SMCs using in vitro single-molecule experiments. We find that cohesin and SMC5/6 do not reel in DNA from both sides, as reported before, but instead extrude DNA asymmetrically, although the direction can switch over time. Asymmetric DNA loop extrusion thus is the shared mechanism across all eukaryotic SMC complexes. For cohesin, direction switches strongly correlate with the turnover of the subunit NIPBL, during which DNA strand switching may occur. Apart from expanding by extrusion, loops frequently diffuse and shrink. The findings reveal that SMCs, surprisingly, can switch directions.
Collapse
Affiliation(s)
- Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Michael Taschner
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands.
| |
Collapse
|
18
|
Rutkauskas M, Kim E. In vitro dynamics of DNA loop extrusion by structural maintenance of chromosomes complexes. Curr Opin Genet Dev 2025; 90:102284. [PMID: 39591812 DOI: 10.1016/j.gde.2024.102284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2024] [Accepted: 11/05/2024] [Indexed: 11/28/2024]
Abstract
Genomic DNA inside the cell's nucleus is highly organized and tightly controlled by the structural maintenance of chromosomes (SMC) protein complexes. These complexes fold genomes by creating and processively enlarging loops, a process called loop extrusion. After more than a decade of accumulating indirect evidence, recent in vitro single-molecule studies confirmed loop extrusion as an evolutionarily conserved function among eukaryotic and prokaryotic SMCs. These studies further provided important insights into mechanisms and regulations of these universal molecular machines, which will be discussed in this minireview.
Collapse
Affiliation(s)
- Marius Rutkauskas
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Eugene Kim
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.
| |
Collapse
|
19
|
Scott JS, Al Ayadi L, Epeslidou E, van Scheppingen RH, Mukha A, Kaaij LJT, Lutz C, Prekovic S. Emerging roles of cohesin-STAG2 in cancer. Oncogene 2025; 44:277-287. [PMID: 39613934 DOI: 10.1038/s41388-024-03221-y] [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: 09/15/2024] [Revised: 10/30/2024] [Accepted: 11/04/2024] [Indexed: 12/01/2024]
Abstract
Cohesin, a crucial regulator of genome organisation, plays a fundamental role in maintaining chromatin architecture as well as gene expression. Among its subunits, STAG2 stands out because of its frequent deleterious mutations in various cancer types, such as bladder cancer and melanoma. Loss of STAG2 function leads to significant alterations in chromatin structure, disrupts transcriptional regulation, and impairs DNA repair pathways. In this review, we explore the molecular mechanisms underlying cohesin-STAG2 function, highlighting its roles in healthy cells and its contributions to cancer biology, showing how STAG2 dysfunction promotes tumourigenesis and presents opportunities for targeted therapeutic interventions.
Collapse
Affiliation(s)
- Julia S Scott
- Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands
| | - Loubna Al Ayadi
- Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands
| | | | | | - Anna Mukha
- Department of Medical BioSciences, RadboudUMC, Nijmegen, The Netherlands
| | - Lucas J T Kaaij
- Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands
| | - Catrin Lutz
- Division of Molecular Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
| | - Stefan Prekovic
- Center for Molecular Medicine, UMC Utrecht, Utrecht, The Netherlands.
| |
Collapse
|
20
|
Coulon A. Interphase chromatin biophysics and mechanics: new perspectives and open questions. Curr Opin Genet Dev 2025; 90:102296. [PMID: 39724779 DOI: 10.1016/j.gde.2024.102296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2024] [Revised: 11/01/2024] [Accepted: 11/26/2024] [Indexed: 12/28/2024]
Abstract
The physical organization and properties of chromatin within the interphase nucleus are intimately linked to a wide range of functional DNA-based processes. In this context, interphase chromatin mechanics - that is, how chromatin, physically, responds to forces - is gaining increasing attention. Recent methodological advances for probing the force-response of chromatin in cellulo open new avenues for research, as well as new questions. This review discusses emerging views from these approaches and others, including recent in vitro single-molecule studies of cohesin and condensin motor activities, providing insights into physical and material aspects of chromatin, its plasticity in the context of functional processes, its nonequilibrium or 'active matter' properties, and the importance of factors such as chromatin fiber tension and stiffness. This growing field offers exciting opportunities to better understand the interplay between interphase chromosome structure, dynamics, mechanics, and functions.
Collapse
Affiliation(s)
- Antoine Coulon
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR3664 Laboratoire Dynamique du Noyau, CNRS UMR168 Laboratoire Physique des Cellules et Cancer, 75005 Paris, France.
| |
Collapse
|
21
|
Ren Z, Way LE, Wang X. SMC translocation is unaffected by an excess of nucleoid associated proteins in vivo. Sci Rep 2025; 15:2447. [PMID: 39828741 PMCID: PMC11743769 DOI: 10.1038/s41598-025-86946-4] [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: 10/31/2024] [Accepted: 01/15/2025] [Indexed: 01/22/2025] Open
Abstract
Genome organization is important for DNA replication, gene expression, and chromosome segregation. In bacteria, two large families of proteins, nucleoid-associated proteins (NAPs) and SMC complexes, play important roles in organizing the genome. NAPs are highly abundant DNA-binding proteins that can bend, wrap, bridge, and compact DNA, while SMC complexes load onto the chromosome, translocate on the DNA, and extrude DNA loops. Although SMC complexes are capable of traversing the entire chromosome bound by various NAPs in vivo, it is unclear whether SMC translocation is influenced by NAPs. In this study, using Bacillus subtilis as a model system, we expressed a collection of representative bacterial and archaeal DNA-binding proteins that introduce distinct DNA structures and potentially pose different challenges for SMC movement. By fluorescence microscopy and chromatin immunoprecipitation, we observed that these proteins bound to the genome in characteristic manners. Using genome-wide chromosome conformation capture (Hi-C) assays, we found that the SMC complex traversed these DNA-binding proteins without slowing down. Our findings revealed that the DNA-loop-extruding activity of the SMC complex is unaffected by exogenously expressed DNA-binding proteins, which highlights the robustness of SMC motors on the busy chromatin.
Collapse
Affiliation(s)
- Zhongqing Ren
- Department of Biology, Indiana University, 1001 E 3rd Street, Bloomington, IN 47405, USA
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Lindsey E Way
- Department of Biology, Indiana University, 1001 E 3rd Street, Bloomington, IN 47405, USA
| | - Xindan Wang
- Department of Biology, Indiana University, 1001 E 3rd Street, Bloomington, IN 47405, USA.
| |
Collapse
|
22
|
Jeppsson K. Structural Maintenance of Chromosomes Complexes. Methods Mol Biol 2025; 2856:11-22. [PMID: 39283444 DOI: 10.1007/978-1-0716-4136-1_2] [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: 11/03/2024]
Abstract
The Structural Maintenance of Chromosomes (SMC) protein complexes are DNA-binding molecular machines required to shape chromosomes into functional units and to safeguard the genome through cell division. These ring-shaped multi-subunit protein complexes, which are present in all kingdoms of life, achieve this by organizing chromosomes in three-dimensional space. Mechanistically, the SMC complexes hydrolyze ATP to either stably entrap DNA molecules within their lumen, or rapidly reel DNA into large loops, which allow them to link two stretches of DNA in cis or trans. In this chapter, the canonical structure of the SMC complexes is first introduced, followed by a description of the composition and general functions of the main types of eukaryotic and prokaryotic SMC complexes. Thereafter, the current model for how SMC complexes perform in vitro DNA loop extrusion is presented. Lastly, chromosome loop formation by SMC complexes is introduced, and how the DNA loop extrusion mechanism contributes to chromosome looping by SMC complexes in cells is discussed.
Collapse
Affiliation(s)
- Kristian Jeppsson
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.
- Karolinska Institutet, Department of Cell and Molecular Biology, Stockholm, Sweden.
| |
Collapse
|
23
|
Platania A, Erb C, Barbieri M, Molcrette B, Grandgirard E, de Kort MAC, Pomp W, Meaburn K, Taylor T, Shchuka VM, Kocanova S, Nazarova M, Oliveira GM, Mitchell JA, Soutoglou E, Lenstra TL, Molina N, Papantonis A, Bystricky K, Sexton T. Transcription processes compete with loop extrusion to homogenize promoter and enhancer dynamics. SCIENCE ADVANCES 2024; 10:eadq0987. [PMID: 39671497 PMCID: PMC11641109 DOI: 10.1126/sciadv.adq0987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 11/07/2024] [Indexed: 12/15/2024]
Abstract
The spatiotemporal configuration of genes with distal regulatory elements is believed to be crucial for transcriptional control, but full mechanistic understanding is lacking. We combine simultaneous live tracking of pairs of genomic loci and nascent transcripts with molecular dynamics simulations to assess the Sox2 gene and its enhancer. We find that both loci exhibit more constrained mobility than control sequences due to stalled cohesin at CCCTC-binding factor sites. Strikingly, enhancer mobility becomes constrained on transcriptional firing, homogenizing its dynamics with the gene promoter, suggestive of their cotranscriptional sharing of a nuclear microenvironment. Furthermore, we find transcription and loop extrusion to be antagonistic processes constraining regulatory loci. These findings indicate that modulating chromatin mobility can be an additional, underestimated means for effective gene regulation.
Collapse
Affiliation(s)
- Angeliki Platania
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Cathie Erb
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Mariano Barbieri
- Translational Epigenetics Group, Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Bastien Molcrette
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Erwan Grandgirard
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Marit A. C. de Kort
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, Netherlands
| | - Wim Pomp
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, Netherlands
| | - Karen Meaburn
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Tiegh Taylor
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M55 3G5, Canada
| | - Virlana M. Shchuka
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M55 3G5, Canada
| | - Silvia Kocanova
- Molecular Cellular and Developmental Biology Unit (MCD), Centre de Biologie Integrative (CBI), University of Toulouse Paul Sabatier, CNRS, 31062 Toulouse, France
| | - Mariia Nazarova
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Guilherme Monteiro Oliveira
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Jennifer A. Mitchell
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M55 3G5, Canada
| | - Evi Soutoglou
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Tineke L. Lenstra
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, 1066CX Amsterdam, Netherlands
| | - Nacho Molina
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| | - Argyris Papantonis
- Translational Epigenetics Group, Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Kerstin Bystricky
- Molecular Cellular and Developmental Biology Unit (MCD), Centre de Biologie Integrative (CBI), University of Toulouse Paul Sabatier, CNRS, 31062 Toulouse, France
- Institut Universitaire de France (IUF), 75005 Paris, France
| | - Tom Sexton
- Department of Functional Genomics and Cancer, Institute of Genetics and Molecular and Cellular Biology (IGBMC), UMR7104, Centre National de la Recherche Scientifique, U1258, Institut National de la Santé et de la Recherche Médicale, University of Strasbourg, 6704 Illkirch, France
| |
Collapse
|
24
|
Martin-Gonzalez A, Tišma M, Analikwu B, Barth A, Janissen R, Antar H, Kemps G, Gruber S, Dekker C. DNA supercoiling enhances DNA condensation by ParB proteins. Nucleic Acids Res 2024; 52:13255-13268. [PMID: 39441069 PMCID: PMC11602141 DOI: 10.1093/nar/gkae936] [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: 07/17/2024] [Revised: 09/27/2024] [Accepted: 10/08/2024] [Indexed: 10/25/2024] Open
Abstract
The ParABS system plays a critical role in bacterial chromosome segregation. The key component of this system, ParB, loads and spreads along DNA to form a local protein-DNA condensate known as a partition complex. As bacterial chromosomes are heavily supercoiled due to the continuous action of RNA polymerases, topoisomerases and nucleoid-associated proteins, it is important to study the impact of DNA supercoiling on the ParB-DNA partition complex formation. Here, we use an in-vitro single-molecule assay to visualize ParB on supercoiled DNA. Unlike most DNA-binding proteins, individual ParB proteins are found to not pin plectonemes on supercoiled DNA, but freely diffuse along supercoiled DNA. We find that DNA supercoiling enhances ParB-DNA condensation, which initiates at lower ParB concentrations than on DNA that is torsionally relaxed. ParB proteins induce a DNA-protein condensate that strikingly absorbs all supercoiling writhe. Our findings provide mechanistic insights that have important implications for our understanding of bacterial chromosome organization and segregation.
Collapse
Affiliation(s)
- Alejandro Martin-Gonzalez
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Miloš Tišma
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Brian T Analikwu
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Anders Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
- BITZ Transformation Lab, Deggendorf Institute of Technology, 94363 Oberschneiding, Germany
| | - Hammam Antar
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL); CH-1015 Lausanne, Switzerland
| | - Gianluca Kemps
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL); CH-1015 Lausanne, Switzerland
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Van der Massweg 9, 2629HZ Delft, Netherlands
| |
Collapse
|
25
|
Dekker J, Mirny LA. The chromosome folding problem and how cells solve it. Cell 2024; 187:6424-6450. [PMID: 39547207 PMCID: PMC11569382 DOI: 10.1016/j.cell.2024.10.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2024] [Revised: 10/15/2024] [Accepted: 10/15/2024] [Indexed: 11/17/2024]
Abstract
Every cell must solve the problem of how to fold its genome. We describe how the folded state of chromosomes is the result of the combined activity of multiple conserved mechanisms. Homotypic affinity-driven interactions lead to spatial partitioning of active and inactive loci. Molecular motors fold chromosomes through loop extrusion. Topological features such as supercoiling and entanglements contribute to chromosome folding and its dynamics, and tethering loci to sub-nuclear structures adds additional constraints. Dramatically diverse chromosome conformations observed throughout the cell cycle and across the tree of life can be explained through differential regulation and implementation of these basic mechanisms. We propose that the first functions of chromosome folding are to mediate genome replication, compaction, and segregation and that mechanisms of folding have subsequently been co-opted for other roles, including long-range gene regulation, in different conditions, cell types, and species.
Collapse
Affiliation(s)
- Job Dekker
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| | - Leonid A Mirny
- Institute for Medical Engineering and Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
| |
Collapse
|
26
|
Prevo B, Earnshaw WC. DNA packaging by molecular motors: from bacteriophage to human chromosomes. Nat Rev Genet 2024; 25:785-802. [PMID: 38886215 DOI: 10.1038/s41576-024-00740-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2024] [Indexed: 06/20/2024]
Abstract
Dense packaging of genomic DNA is crucial for organismal survival, as DNA length always far exceeds the dimensions of the cells that contain it. Organisms, therefore, use sophisticated machineries to package their genomes. These systems range across kingdoms from a single ultra-powerful rotary motor that spools the DNA into a bacteriophage head, to hundreds of thousands of relatively weak molecular motors that coordinate the compaction of mitotic chromosomes in eukaryotic cells. Recent technological advances, such as DNA proximity-based sequencing approaches, polymer modelling and in vitro reconstitution of DNA loop extrusion, have shed light on the biological mechanisms driving DNA organization in different systems. Here, we discuss DNA packaging in bacteriophage, bacteria and eukaryotic cells, which, despite their extreme variation in size, structure and genomic content, all rely on the action of molecular motors to package their genomes.
Collapse
Affiliation(s)
- Bram Prevo
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK.
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK.
| |
Collapse
|
27
|
Dasgupta M, Guha S, Armbruster L, Das D, Mitra MK. Nature of barriers determines first passage times in heterogeneous media. SOFT MATTER 2024; 20:8353-8362. [PMID: 39318347 DOI: 10.1039/d4sm00908h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2024]
Abstract
Intuition suggests that passage times across a region increase with the number of barriers along the path. Can this fail depending on the nature of the barrier? To probe this fundamental question, we exactly solve for the first passage time in general d-dimensions for diffusive transport through a spatially patterned array of obstacles - either entropic or energetic, depending on the nature of the obstacles. For energetic barriers, we show that first passage times vary non-monotonically with the number of barriers, while for entropic barriers it increases monotonically. This non-monotonicity for energetic barriers is further reflected in the behaviour of effective diffusivity as well. We then design a simple experiment where a robotic bug navigates in a heterogeneous environment through a spatially patterned array of obstacles to validate our predictions. Finally, using numerical simulations, we show that this non-monotonic behaviour for energetic barriers is general and extends to even super-diffusive transport.
Collapse
Affiliation(s)
| | - Sougata Guha
- Department of Physics, IIT Bombay, Mumbai 400076, India.
- INFN Napoli, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy
| | | | - Dibyendu Das
- Department of Physics, IIT Bombay, Mumbai 400076, India.
| | - Mithun K Mitra
- Department of Physics, IIT Bombay, Mumbai 400076, India.
| |
Collapse
|
28
|
Guérin TM, Barrington C, Pobegalov G, Molodtsov MI, Uhlmann F. An extrinsic motor directs chromatin loop formation by cohesin. EMBO J 2024; 43:4173-4196. [PMID: 39160275 PMCID: PMC11445435 DOI: 10.1038/s44318-024-00202-5] [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: 03/05/2024] [Revised: 07/30/2024] [Accepted: 07/31/2024] [Indexed: 08/21/2024] Open
Abstract
The ring-shaped cohesin complex topologically entraps two DNA molecules to establish sister chromatid cohesion. Cohesin also shapes the interphase chromatin landscape with wide-ranging implications for gene regulation, and cohesin is thought to achieve this by actively extruding DNA loops without topologically entrapping DNA. The 'loop extrusion' hypothesis finds motivation from in vitro observations-whether this process underlies in vivo chromatin loop formation remains untested. Here, using the budding yeast S. cerevisiae, we generate cohesin variants that have lost their ability to extrude DNA loops but retain their ability to topologically entrap DNA. Analysis of these variants suggests that in vivo chromatin loops form independently of loop extrusion. Instead, we find that transcription promotes loop formation, and acts as an extrinsic motor that expands these loops and defines their ultimate positions. Our results necessitate a re-evaluation of the loop extrusion hypothesis. We propose that cohesin, akin to sister chromatid cohesion establishment at replication forks, forms chromatin loops by DNA-DNA capture at places of transcription, thus unifying cohesin's two roles in chromosome segregation and interphase genome organisation.
Collapse
Affiliation(s)
- Thomas M Guérin
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
- Université Paris Cité and Université Paris-Saclay, Inserm, CEA, Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, France
| | - Christopher Barrington
- Bioinformatics & Biostatistics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Georgii Pobegalov
- Mechanobiology and Biophysics Laboratory, The Francis Crick Institute, London, UK
- Department of Physics and Astronomy, University College London, London, UK
| | - Maxim I Molodtsov
- Mechanobiology and Biophysics Laboratory, The Francis Crick Institute, London, UK
- Department of Physics and Astronomy, University College London, London, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
| |
Collapse
|
29
|
Ortabozkoyun H, Huang PY, Gonzalez-Buendia E, Cho H, Kim SY, Tsirigos A, Mazzoni EO, Reinberg D. Members of an array of zinc-finger proteins specify distinct Hox chromatin boundaries. Mol Cell 2024; 84:3406-3422.e6. [PMID: 39173638 DOI: 10.1016/j.molcel.2024.08.007] [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: 10/20/2023] [Revised: 05/06/2024] [Accepted: 08/05/2024] [Indexed: 08/24/2024]
Abstract
Partitioning of repressive from actively transcribed chromatin in mammalian cells fosters cell-type-specific gene expression patterns. While this partitioning is reconstructed during differentiation, the chromatin occupancy of the key insulator, CCCTC-binding factor (CTCF), is unchanged at the developmentally important Hox clusters. Thus, dynamic changes in chromatin boundaries must entail other activities. Given its requirement for chromatin loop formation, we examined cohesin-based chromatin occupancy without known insulators, CTCF and Myc-associated zinc-finger protein (MAZ), and identified a family of zinc-finger proteins (ZNFs), some of which exhibit tissue-specific expression. Two such ZNFs foster chromatin boundaries at the Hox clusters that are distinct from each other and from MAZ. PATZ1 was critical to the thoracolumbar boundary in differentiating motor neurons and mouse skeleton, while ZNF263 contributed to cervicothoracic boundaries. We propose that these insulating activities act with cohesin, alone or combinatorially, with or without CTCF, to implement precise positional identity and cell fate during development.
Collapse
Affiliation(s)
- Havva Ortabozkoyun
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA.
| | - Pin-Yao Huang
- Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA
| | - Edgar Gonzalez-Buendia
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA
| | - Hyein Cho
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA; Applied Bioinformatics Laboratories, NYU Langone Health, New York, NY 10016, USA; Department of Medicine, Division of Precision Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Sang Y Kim
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA
| | - Aristotelis Tsirigos
- Department of Pathology, NYU Langone Health, New York, NY 10016, USA; Applied Bioinformatics Laboratories, NYU Langone Health, New York, NY 10016, USA; Institute for Computational Medicine, NYU Langone Health, New York, NY 10016, USA
| | - Esteban O Mazzoni
- Department of Cell Biology, NYU Langone Health, New York, NY 10016, USA
| | - Danny Reinberg
- Howard Hughes Medical Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA.
| |
Collapse
|
30
|
Ortabozkoyun H, Huang PY, Gonzalez-Buendia E, Cho H, Kim SY, Tsirigos A, Mazzoni EO, Reinberg D. Members of an array of zinc finger proteins specify distinct Hox chromatin boundaries. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.25.538167. [PMID: 37162865 PMCID: PMC10168243 DOI: 10.1101/2023.04.25.538167] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Partitioning of repressive from actively transcribed chromatin in mammalian cells fosters cell-type specific gene expression patterns. While this partitioning is reconstructed during differentiation, the chromatin occupancy of the key insulator, CTCF, is unchanged at the developmentally important Hox clusters. Thus, dynamic changes in chromatin boundaries must entail other activities. Given its requirement for chromatin loop formation, we examined cohesin-based chromatin occupancy without known insulators, CTCF and MAZ, and identified a family of zinc finger proteins (ZNFs), some of which exhibit tissue-specific expression. Two such ZNFs foster chromatin boundaries at the Hox clusters that are distinct from each other and from MAZ. PATZ1 was critical to the thoracolumbar boundary in differentiating motor neurons and mouse skeleton, while ZNF263 contributed to cervicothoracic boundaries. We propose that these insulating activities act with cohesin, alone or combinatorially, with or without CTCF, to implement precise positional identity and cell fate during development.
Collapse
|
31
|
Moon KW, Kim DG, Ryu JK. Anisotropic scrunching of SMC with a baton-pass mechanism. Commun Biol 2024; 7:881. [PMID: 39030299 PMCID: PMC11271495 DOI: 10.1038/s42003-024-06557-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 07/04/2024] [Indexed: 07/21/2024] Open
Abstract
DNA-loop extrusion is considered to be a universal principle of structural maintenance of chromosome (SMC) proteins with regard to chromosome organization. Despite recent advancements in structural dynamics studies that involve the use of cryogenic-electron microscopy (Cryo-EM), atomic force microscopy (AFM), etc., the precise molecular mechanism underlying DNA-loop extrusion by SMC proteins remains the subject of ongoing discussions. In this context, we propose a scrunching model that incorporates the anisotropic motion of SMC folding with a baton-pass mechanism, offering a potential explanation of how a "DNA baton" is transferred from the hinge domain to a DNA pocket via an anisotropic hinge motion. This proposed model provides insights into how SMC proteins unidirectionally extrude DNA loops in the direction of loop elongation while also maintaining the stability of a DNA loop throughout the dynamic process of DNA-loop extrusion.
Collapse
Affiliation(s)
- Kyoung-Wook Moon
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
| | - Do-Gyun Kim
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
| | - Je-Kyung Ryu
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea.
- Institute of Applied Physics of Seoul National University, Seoul, South Korea.
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea.
- Department of Biological Sciences, Seoul National University, Seoul, South Korea.
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, South Korea.
| |
Collapse
|
32
|
Chua GNL, Liu S. When Force Met Fluorescence: Single-Molecule Manipulation and Visualization of Protein-DNA Interactions. Annu Rev Biophys 2024; 53:169-191. [PMID: 38237015 DOI: 10.1146/annurev-biophys-030822-032904] [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: 06/26/2024]
Abstract
Myriad DNA-binding proteins undergo dynamic assembly, translocation, and conformational changes while on DNA or alter the physical configuration of the DNA substrate to control its metabolism. It is now possible to directly observe these activities-often central to the protein function-thanks to the advent of single-molecule fluorescence- and force-based techniques. In particular, the integration of fluorescence detection and force manipulation has unlocked multidimensional measurements of protein-DNA interactions and yielded unprecedented mechanistic insights into the biomolecular processes that orchestrate cellular life. In this review, we first introduce the different experimental geometries developed for single-molecule correlative force and fluorescence microscopy, with a focus on optical tweezers as the manipulation technique. We then describe the utility of these integrative platforms for imaging protein dynamics on DNA and chromatin, as well as their unique capabilities in generating complex DNA configurations and uncovering force-dependent protein behaviors. Finally, we give a perspective on the future directions of this emerging research field.
Collapse
Affiliation(s)
- Gabriella N L Chua
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, New York, USA;
- Tri-Institutional PhD Program in Chemical Biology, New York, New York, USA
| | - Shixin Liu
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, New York, USA;
| |
Collapse
|
33
|
Harju J, van Teeseling MCF, Broedersz CP. Loop-extruders alter bacterial chromosome topology to direct entropic forces for segregation. Nat Commun 2024; 15:4618. [PMID: 38816445 PMCID: PMC11139863 DOI: 10.1038/s41467-024-49039-w] [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: 11/28/2023] [Accepted: 05/21/2024] [Indexed: 06/01/2024] Open
Abstract
Entropic forces have been argued to drive bacterial chromosome segregation during replication. In many bacterial species, however, specifically evolved mechanisms, such as loop-extruding SMC complexes and the ParABS origin segregation system, contribute to or are even required for chromosome segregation, suggesting that entropic forces alone may be insufficient. The interplay between and the relative contributions of these segregation mechanisms remain unclear. Here, we develop a biophysical model showing that purely entropic forces actually inhibit bacterial chromosome segregation until late replication stages. By contrast, our model reveals that loop-extruders loaded at the origins of replication, as observed in many bacterial species, alter the effective topology of the chromosome, thereby redirecting and enhancing entropic forces to enable accurate chromosome segregation during replication. We confirm our model predictions with polymer simulations: purely entropic forces do not allow for concurrent replication and segregation, whereas entropic forces steered by specifically loaded loop-extruders lead to robust, global chromosome segregation during replication. Finally, we show how loop-extruders can complement locally acting origin separation mechanisms, such as the ParABS system. Together, our results illustrate how changes in the geometry and topology of the polymer, induced by DNA-replication and loop-extrusion, impact the organization and segregation of bacterial chromosomes.
Collapse
Affiliation(s)
- Janni Harju
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Muriel C F van Teeseling
- Junior research group Prokaryotic Cell Biology, Department for Microbial Interactions, Institute of Microbiology, Friedrich-Schiller-Universität, Jena, Germany
| | - Chase P Broedersz
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilian-University Munich, Munich, Germany.
| |
Collapse
|
34
|
Oberbeckmann E, Oudelaar AM. Genome organization across scales: mechanistic insights from in vitro reconstitution studies. Biochem Soc Trans 2024; 52:793-802. [PMID: 38451192 PMCID: PMC11088924 DOI: 10.1042/bst20230883] [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: 01/12/2024] [Revised: 02/19/2024] [Accepted: 02/27/2024] [Indexed: 03/08/2024]
Abstract
Eukaryotic genomes are compacted and organized into distinct three-dimensional (3D) structures, which range from small-scale nucleosome arrays to large-scale chromatin domains. These chromatin structures play an important role in the regulation of transcription and other nuclear processes. The molecular mechanisms that drive the formation of chromatin structures across scales and the relationship between chromatin structure and function remain incompletely understood. Because the processes involved are complex and interconnected, it is often challenging to dissect the underlying principles in the nuclear environment. Therefore, in vitro reconstitution systems provide a valuable approach to gain insight into the molecular mechanisms by which chromatin structures are formed and to determine the cause-consequence relationships between the processes involved. In this review, we give an overview of in vitro approaches that have been used to study chromatin structures across scales and how they have increased our understanding of the formation and function of these structures. We start by discussing in vitro studies that have given insight into the mechanisms of nucleosome positioning. Next, we discuss recent efforts to reconstitute larger-scale chromatin domains and loops and the resulting insights into the principles of genome organization. We conclude with an outlook on potential future applications of chromatin reconstitution systems and how they may contribute to answering open questions concerning chromatin architecture.
Collapse
Affiliation(s)
- Elisa Oberbeckmann
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| | - A. Marieke Oudelaar
- Genome Organization and Regulation, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
| |
Collapse
|
35
|
Rogers AM, Neri NR, Chigweshe L, Holmes SG. Histone variant H2A.Z and linker histone H1 influence chromosome condensation in Saccharomyces cerevisiae. Genetics 2024; 226:iyae022. [PMID: 38366024 PMCID: PMC10990423 DOI: 10.1093/genetics/iyae022] [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: 10/15/2023] [Revised: 10/15/2023] [Accepted: 01/17/2024] [Indexed: 02/18/2024] Open
Abstract
Chromosome condensation is essential for the fidelity of chromosome segregation during mitosis and meiosis. Condensation is associated both with local changes in nucleosome structure and larger-scale alterations in chromosome topology mediated by the condensin complex. We examined the influence of linker histone H1 and variant histone H2A.Z on chromosome condensation in budding yeast cells. Linker histone H1 has been implicated in local and global compaction of chromatin in multiple eukaryotes, but we observe normal condensation of the rDNA locus in yeast strains lacking H1. However, deletion of the yeast HTZ1 gene, coding for variant histone H2A.Z, causes a significant defect in rDNA condensation. Loss of H2A.Z does not change condensin association with the rDNA locus or significantly affect condensin mRNA levels. Prior studies reported that several phenotypes caused by loss of H2A.Z are suppressed by eliminating Swr1, a key component of the SWR complex that deposits H2A.Z in chromatin. We observe that an htz1Δ swr1Δ strain has near-normal rDNA condensation. Unexpectedly, we find that elimination of the linker histone H1 can also suppress the rDNA condensation defect of htz1Δ strains. Our experiments demonstrate that histone H2A.Z promotes chromosome condensation, in part by counteracting activities of histone H1 and the SWR complex.
Collapse
Affiliation(s)
- Anna M Rogers
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | - Nola R Neri
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | - Lorencia Chigweshe
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| | - Scott G Holmes
- Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, CT 06459, USA
| |
Collapse
|
36
|
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.
Collapse
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.
| |
Collapse
|
37
|
Rittenhouse NL, Dowen JM. Cohesin regulation and roles in chromosome structure and function. Curr Opin Genet Dev 2024; 85:102159. [PMID: 38382406 PMCID: PMC10947815 DOI: 10.1016/j.gde.2024.102159] [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: 09/12/2023] [Revised: 01/22/2024] [Accepted: 01/27/2024] [Indexed: 02/23/2024]
Abstract
Chromosome structure regulates DNA-templated processes such as transcription of genes. Dynamic changes to chromosome structure occur during development and in disease contexts. The cohesin complex is a molecular motor that regulates chromosome structure by generating DNA loops that bring two distal genomic sites into close spatial proximity. There are many open questions regarding the formation and dissolution of DNA loops, as well as the role(s) of DNA loops in regulating transcription of the interphase genome. This review focuses on recent discoveries that provide molecular insights into the role of cohesin and chromosome structure in gene transcription during development and disease.
Collapse
Affiliation(s)
- Natalie L Rittenhouse
- Curriculum in Genetics & Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jill M Dowen
- Department of Biophysics & Biochemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| |
Collapse
|
38
|
Lebreton J, Colin L, Chatre E, Bernard P. RNAP II antagonizes mitotic chromatin folding and chromosome segregation by condensin. Cell Rep 2024; 43:113901. [PMID: 38446663 DOI: 10.1016/j.celrep.2024.113901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 12/07/2023] [Accepted: 02/16/2024] [Indexed: 03/08/2024] Open
Abstract
Condensin shapes mitotic chromosomes by folding chromatin into loops, but whether it does so by DNA-loop extrusion remains speculative. Although loop-extruding cohesin is stalled by transcription, the impact of transcription on condensin, which is enriched at highly expressed genes in many species, remains unclear. Using degrons of Rpb1 or the torpedo nuclease Dhp1XRN2 to either deplete or displace RNAPII on chromatin in fission yeast metaphase cells, we show that RNAPII does not load condensin on DNA. Instead, RNAPII retains condensin in cis and hinders its ability to fold mitotic chromatin and to support chromosome segregation, consistent with the stalling of a loop extruder. Transcription termination by Dhp1 limits such a hindrance. Our results shed light on the integrated functioning of condensin, and we argue that a tight control of transcription underlies mitotic chromosome assembly by loop-extruding condensin.
Collapse
Affiliation(s)
- Jérémy Lebreton
- ENS de Lyon, University Lyon, 46 allée d'Italie, 69007 Lyon, France
| | - Léonard Colin
- CNRS Laboratory of Biology and Modelling of the Cell, UMR 5239, ENS de Lyon, 46 allée d'Italie, 69007 Lyon, France
| | - Elodie Chatre
- Lymic-Platim, University Lyon, Université Claude Bernard Lyon 1, ENS de Lyon, CNRS UAR3444, Inserm US8, SFR Biosciences, 50 Avenue Tony Garnier, 69007 Lyon, France
| | - Pascal Bernard
- ENS de Lyon, University Lyon, 46 allée d'Italie, 69007 Lyon, France; CNRS Laboratory of Biology and Modelling of the Cell, UMR 5239, ENS de Lyon, 46 allée d'Italie, 69007 Lyon, France.
| |
Collapse
|
39
|
Bastié N, Chapard C, Cournac A, Nejmi S, Mboumba H, Gadal O, Thierry A, Beckouët F, Koszul R. Sister chromatid cohesion halts DNA loop expansion. Mol Cell 2024; 84:1139-1148.e5. [PMID: 38452765 DOI: 10.1016/j.molcel.2024.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 12/02/2023] [Accepted: 02/06/2024] [Indexed: 03/09/2024]
Abstract
Eukaryotic genomes are folded into DNA loops mediated by structural maintenance of chromosomes (SMC) complexes such as cohesin, condensin, and Smc5/6. This organization regulates different DNA-related processes along the cell cycle, such as transcription, recombination, segregation, and DNA repair. During the G2 stage, SMC-mediated DNA loops coexist with cohesin complexes involved in sister chromatid cohesion (SCC). However, the articulation between the establishment of SCC and the formation of SMC-mediated DNA loops along the chromatin remains unknown. Here, we show that SCC is indeed a barrier to cohesin-mediated DNA loop expansion along G2/M Saccharomyces cerevisiae chromosomes.
Collapse
Affiliation(s)
- Nathalie Bastié
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Christophe Chapard
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015 Paris, France
| | - Axel Cournac
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015 Paris, France
| | - Sanae Nejmi
- Cancer Research Centre of Toulouse, INSERM UMR 1037, 31037 Toulouse, France
| | - Henri Mboumba
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Olivier Gadal
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Agnès Thierry
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015 Paris, France
| | - Frederic Beckouët
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France.
| | - Romain Koszul
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015 Paris, France.
| |
Collapse
|
40
|
Jeppsson K, Pradhan B, Sutani T, Sakata T, Umeda Igarashi M, Berta DG, Kanno T, Nakato R, Shirahige K, Kim E, Björkegren C. Loop-extruding Smc5/6 organizes transcription-induced positive DNA supercoils. Mol Cell 2024; 84:867-882.e5. [PMID: 38295804 DOI: 10.1016/j.molcel.2024.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 11/16/2023] [Accepted: 01/08/2024] [Indexed: 03/10/2024]
Abstract
The structural maintenance of chromosomes (SMC) protein complexes-cohesin, condensin, and the Smc5/6 complex (Smc5/6)-are essential for chromosome function. At the molecular level, these complexes fold DNA by loop extrusion. Accordingly, cohesin creates chromosome loops in interphase, and condensin compacts mitotic chromosomes. However, the role of Smc5/6's recently discovered DNA loop extrusion activity is unknown. Here, we uncover that Smc5/6 associates with transcription-induced positively supercoiled DNA at cohesin-dependent loop boundaries on budding yeast (Saccharomyces cerevisiae) chromosomes. Mechanistically, single-molecule imaging reveals that dimers of Smc5/6 specifically recognize the tip of positively supercoiled DNA plectonemes and efficiently initiate loop extrusion to gather the supercoiled DNA into a large plectonemic loop. Finally, Hi-C analysis shows that Smc5/6 links chromosomal regions containing transcription-induced positive supercoiling in cis. Altogether, our findings indicate that Smc5/6 controls the three-dimensional organization of chromosomes by recognizing and initiating loop extrusion on positively supercoiled DNA.
Collapse
Affiliation(s)
- Kristian Jeppsson
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden; Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden; Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
| | - Biswajit Pradhan
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Takashi Sutani
- Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Toyonori Sakata
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden; Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden; Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Miki Umeda Igarashi
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden; Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden
| | - Davide Giorgio Berta
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden
| | - Takaharu Kanno
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden; Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden
| | - Ryuichiro Nakato
- Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Katsuhiko Shirahige
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden; Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden; Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Eugene Kim
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.
| | - Camilla Björkegren
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden; Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden.
| |
Collapse
|
41
|
Roisné-Hamelin F, Liu HW, Taschner M, Li Y, Gruber S. Structural basis for plasmid restriction by SMC JET nuclease. Mol Cell 2024; 84:883-896.e7. [PMID: 38309275 DOI: 10.1016/j.molcel.2024.01.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/06/2023] [Accepted: 01/09/2024] [Indexed: 02/05/2024]
Abstract
DNA loop-extruding SMC complexes play crucial roles in chromosome folding and DNA immunity. Prokaryotic SMC Wadjet (JET) complexes limit the spread of plasmids through DNA cleavage, yet the mechanisms for plasmid recognition are unresolved. We show that artificial DNA circularization renders linear DNA susceptible to JET nuclease cleavage. Unlike free DNA, JET cleaves immobilized plasmid DNA at a specific site, the plasmid-anchoring point, showing that the anchor hinders DNA extrusion but not DNA cleavage. Structures of plasmid-bound JetABC reveal two presumably stalled SMC motor units that are drastically rearranged from the resting state, together entrapping a U-shaped DNA segment, which is further converted to kinked V-shaped cleavage substrate by JetD nuclease binding. Our findings uncover mechanical bending of residual unextruded DNA as molecular signature for plasmid recognition and non-self DNA elimination. We moreover elucidate key elements of SMC loop extrusion, including the motor direction and the structure of a DNA-holding state.
Collapse
Affiliation(s)
- Florian Roisné-Hamelin
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Hon Wing Liu
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Michael Taschner
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Yan Li
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), 1015 Lausanne, Switzerland.
| |
Collapse
|
42
|
Janissen R, Barth R, Polinder M, van der Torre J, Dekker C. Single-molecule visualization of twin-supercoiled domains generated during transcription. Nucleic Acids Res 2024; 52:1677-1687. [PMID: 38084930 PMCID: PMC10899792 DOI: 10.1093/nar/gkad1181] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/13/2023] [Accepted: 11/30/2023] [Indexed: 02/29/2024] Open
Abstract
Transcription-coupled supercoiling of DNA is a key factor in chromosome compaction and the regulation of genetic processes in all domains of life. It has become common knowledge that, during transcription, the DNA-dependent RNA polymerase (RNAP) induces positive supercoiling ahead of it (downstream) and negative supercoils in its wake (upstream), as rotation of RNAP around the DNA axis upon tracking its helical groove gets constrained due to drag on its RNA transcript. Here, we experimentally validate this so-called twin-supercoiled-domain model with in vitro real-time visualization at the single-molecule scale. Upon binding to the promoter site on a supercoiled DNA molecule, RNAP merges all DNA supercoils into one large pinned plectoneme with RNAP residing at its apex. Transcription by RNAP in real time demonstrates that up- and downstream supercoils are generated simultaneously and in equal portions, in agreement with the twin-supercoiled-domain model. Experiments carried out in the presence of RNases A and H, revealed that an additional viscous drag of the RNA transcript is not necessary for the RNAP to induce supercoils. The latter results contrast the current consensus and simulations on the origin of the twin-supercoiled domains, pointing at an additional mechanistic cause underlying supercoil generation by RNAP in transcription.
Collapse
Affiliation(s)
- Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Minco Polinder
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| |
Collapse
|
43
|
Seba M, Boccard F, Duigou S. Activity of MukBEF for chromosome management in E. coli and its inhibition by MatP. eLife 2024; 12:RP91185. [PMID: 38315099 PMCID: PMC10945525 DOI: 10.7554/elife.91185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024] Open
Abstract
Structural maintenance of chromosomes (SMC) complexes share conserved structures and serve a common role in maintaining chromosome architecture. In the bacterium Escherichia coli, the SMC complex MukBEF is necessary for rapid growth and the accurate segregation and positioning of the chromosome, although the specific molecular mechanisms involved are still unknown. Here, we used a number of in vivo assays to reveal how MukBEF controls chromosome conformation and how the MatP/matS system prevents MukBEF activity. Our results indicate that the loading of MukBEF occurs preferentially on newly replicated DNA, at multiple loci on the chromosome where it can promote long-range contacts in cis even though MukBEF can promote long-range contacts in the absence of replication. Using Hi-C and ChIP-seq analyses in strains with rearranged chromosomes, the prevention of MukBEF activity increases with the number of matS sites and this effect likely results from the unloading of MukBEF by MatP. Altogether, our results reveal how MukBEF operates to control chromosome folding and segregation in E. coli.
Collapse
Affiliation(s)
- Mohammed Seba
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, Gif-sur-Yvette, France
| | - Frederic Boccard
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, Gif-sur-Yvette, France
| | - Stéphane Duigou
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, Gif-sur-Yvette, France
| |
Collapse
|
44
|
O’Brien MP, Pryzhkova MV, Lake EMR, Mandino F, Shen X, Karnik R, Atkins A, Xu MJ, Ji W, Konstantino M, Brueckner M, Ment LR, Khokha MK, Jordan PW. SMC5 Plays Independent Roles in Congenital Heart Disease and Neurodevelopmental Disability. Int J Mol Sci 2023; 25:430. [PMID: 38203602 PMCID: PMC10779392 DOI: 10.3390/ijms25010430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
Up to 50% of patients with severe congenital heart disease (CHD) develop life-altering neurodevelopmental disability (NDD). It has been presumed that NDD arises in CHD cases because of hypoxia before, during, or after cardiac surgery. Recent studies detected an enrichment in de novo mutations in CHD and NDD, as well as significant overlap between CHD and NDD candidate genes. However, there is limited evidence demonstrating that genes causing CHD can produce NDD independent of hypoxia. A patient with hypoplastic left heart syndrome and gross motor delay presented with a de novo mutation in SMC5. Modeling mutation of smc5 in Xenopus tropicalis embryos resulted in reduced heart size, decreased brain length, and disrupted pax6 patterning. To evaluate the cardiac development, we induced the conditional knockout (cKO) of Smc5 in mouse cardiomyocytes, which led to the depletion of mature cardiomyocytes and abnormal contractility. To test a role for Smc5 specifically in the brain, we induced cKO in the mouse central nervous system, which resulted in decreased brain volume, and diminished connectivity between areas related to motor function but did not affect vascular or brain ventricular volume. We propose that genetic factors, rather than hypoxia alone, can contribute when NDD and CHD cases occur concurrently.
Collapse
Affiliation(s)
- Matthew P. O’Brien
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Marina V. Pryzhkova
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology, Uniformed Services, University of the Health Sciences, 4301 Jones Bridge Rd, Bethesda, MD 20814, USA
| | - Evelyn M. R. Lake
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Francesca Mandino
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Xilin Shen
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Ruchika Karnik
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Alisa Atkins
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
| | - Michelle J. Xu
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
| | - Weizhen Ji
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Monica Konstantino
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Martina Brueckner
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Laura R. Ment
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Mustafa K. Khokha
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Pediatric Genomics Discovery Program, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Philip W. Jordan
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, 615 N Wolfe St, Baltimore, MD 21205, USA
- Department of Biochemistry and Molecular Biology, Uniformed Services, University of the Health Sciences, 4301 Jones Bridge Rd, Bethesda, MD 20814, USA
| |
Collapse
|
45
|
Tišma M, Janissen R, Antar H, Martin-Gonzalez A, Barth R, Beekman T, van der Torre J, Michieletto D, Gruber S, Dekker C. Dynamic ParB-DNA interactions initiate and maintain a partition condensate for bacterial chromosome segregation. Nucleic Acids Res 2023; 51:11856-11875. [PMID: 37850647 PMCID: PMC10681803 DOI: 10.1093/nar/gkad868] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/05/2023] [Accepted: 09/26/2023] [Indexed: 10/19/2023] Open
Abstract
In most bacteria, chromosome segregation is driven by the ParABS system where the CTPase protein ParB loads at the parS site to trigger the formation of a large partition complex. Here, we present in vitro studies of the partition complex for Bacillus subtilis ParB, using single-molecule fluorescence microscopy and AFM imaging to show that transient ParB-ParB bridges are essential for forming DNA condensates. Molecular Dynamics simulations confirm that condensation occurs abruptly at a critical concentration of ParB and show that multimerization is a prerequisite for forming the partition complex. Magnetic tweezer force spectroscopy on mutant ParB proteins demonstrates that CTP hydrolysis at the N-terminal domain is essential for DNA condensation. Finally, we show that transcribing RNA polymerases can steadily traverse the ParB-DNA partition complex. These findings uncover how ParB forms a stable yet dynamic partition complex for chromosome segregation that induces DNA condensation and segregation while enabling replication and transcription.
Collapse
Affiliation(s)
- Miloš Tišma
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Hammam Antar
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Alejandro Martin-Gonzalez
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Twan Beekman
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Davide Michieletto
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Stephan Gruber
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| |
Collapse
|
46
|
Yang H, Shi X. The Free Energy of Nucleosomal DNA Based on the Landau Model and Topology. Biomolecules 2023; 13:1686. [PMID: 38136559 PMCID: PMC10741420 DOI: 10.3390/biom13121686] [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: 09/10/2023] [Revised: 10/30/2023] [Accepted: 11/09/2023] [Indexed: 12/24/2023] Open
Abstract
The free energy of nucleosomal DNA plays a key role in the formation of nucleosomes in eukaryotes. Some work on the free energy of nucleosomal DNA have been carried out in experiments. However, the relationships between the free energy of nucleosomal DNA and its conformation, especially its topology, remain unclear in theory. By combining the Landau theory, the Hopfion model and experimental data, we find that the free energy of nucleosomal DNA is at the lower level. With the help of the energy minimum principle, we conclude that nucleosomal DNA stays in a stable state. Moreover, we discover that small perturbations on nucleosomal DNA have little effect on its free energy. This implies that nucleosomal DNA has a certain redundancy in order to stay stable. This explains why nucleosomal DNA will not change significantly due to small perturbations.
Collapse
Affiliation(s)
| | - Xuguang Shi
- College of Science, Beijing Forestry University, Beijing 100083, China;
| |
Collapse
|
47
|
Abstract
A potential mechanism of DNA loop extrusion by molecular motors is discussed.
Collapse
Affiliation(s)
- Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Christian H Haering
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Campus-Vienna-Biocenter 1, Vienna, Austria
| | - Benjamin D Rowland
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, Netherlands
| |
Collapse
|
48
|
Tang M, Pobegalov G, Tanizawa H, Chen ZA, Rappsilber J, Molodtsov M, Noma KI, Uhlmann F. Establishment of dsDNA-dsDNA interactions by the condensin complex. Mol Cell 2023; 83:3787-3800.e9. [PMID: 37820734 PMCID: PMC10842940 DOI: 10.1016/j.molcel.2023.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/13/2023] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
Condensin is a structural maintenance of chromosomes (SMC) complex family member thought to build mitotic chromosomes by DNA loop extrusion. However, condensin variants unable to extrude loops, yet proficient in chromosome formation, were recently described. Here, we explore how condensin might alternatively build chromosomes. Using bulk biochemical and single-molecule experiments with purified fission yeast condensin, we observe that individual condensins sequentially and topologically entrap two double-stranded DNAs (dsDNAs). Condensin loading transitions through a state requiring DNA bending, as proposed for the related cohesin complex. While cohesin then favors the capture of a second single-stranded DNA (ssDNA), second dsDNA capture emerges as a defining feature of condensin. We provide complementary in vivo evidence for DNA-DNA capture in the form of condensin-dependent chromatin contacts within, as well as between, chromosomes. Our results support a "diffusion capture" model in which condensin acts in mitotic chromosome formation by sequential dsDNA-dsDNA capture.
Collapse
Affiliation(s)
- Minzhe Tang
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Georgii Pobegalov
- Mechanobiology and Biophysics Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Hideki Tanizawa
- Division of Genome Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan
| | - Zhuo A Chen
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Juri Rappsilber
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany; Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Maxim Molodtsov
- Mechanobiology and Biophysics Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Ken-Ichi Noma
- Division of Genome Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Cell Biology Centre, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa 226-0026, Japan.
| |
Collapse
|
49
|
Wang C, Manders F, Groh L, Oldenkamp R, Logie C. Corticosteroid-induced chromatin loop dynamics at the FKBP5 gene. Ann N Y Acad Sci 2023; 1529:109-119. [PMID: 37796452 DOI: 10.1111/nyas.15064] [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: 10/06/2023]
Abstract
FKBP5 is a 115-kb-long glucocorticoid-inducible gene implicated in psychiatric disorders. To investigate the complexities of chromatin interaction frequencies at the FKBP5 topologically associated domain (TAD), we deployed 15 one-to-all chromatin capture viewpoints near gene promoters, enhancers, introns, and CTCF-loop anchors. This revealed a "one-TAD-one-gene" structure encompassing the FKBP5 promoter and its enhancers. The FKBP5 promoter and its two glucocorticoid-stimulated enhancers roam the entire TAD while displaying subtle cell type-specific interactomes. The FKBP5 TAD consists of two nested CTCF loops that are coordinated by one CTCF site in the eighth intron of FKBP5 and another beyond its polyadenylation site, 61 kb further. Loop extension correlates with transcription increases through the intronic CTCF site. This is efficiently compensated for, since the short loop is restored even under high transcription regimes. The boundaries of the FKBP5 TAD consist of divergent CTCF site patterns, harbor multiple smaller genes, and are resilient to glucocorticoid stimulation. Interestingly, both FKBP5 TAD boundaries harbor H3K27me3-marked heterochromatin blocks that may reinforce them. We propose that cis-acting genetic and epigenetic polymorphisms underlying FKBP5 expression variation are likely to reside within a 240-kb region that consists of the FKBP5 TAD, its left sub-TAD, and both its boundaries.
Collapse
Affiliation(s)
- Cheng Wang
- Department of Molecular Biology, Radboud Institute for Molecular Science, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| | - Freek Manders
- Department of Molecular Biology, Radboud Institute for Molecular Science, Faculty of Science, Radboud University, Nijmegen, The Netherlands
- Gendx, Utrecht, The Netherlands
| | - Laszlo Groh
- Department of Molecular Biology, Radboud Institute for Molecular Science, Faculty of Science, Radboud University, Nijmegen, The Netherlands
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Roel Oldenkamp
- Department of Molecular Biology, Radboud Institute for Molecular Science, Faculty of Science, Radboud University, Nijmegen, The Netherlands
- Division of Cell Biology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Colin Logie
- Department of Molecular Biology, Radboud Institute for Molecular Science, Faculty of Science, Radboud University, Nijmegen, The Netherlands
| |
Collapse
|
50
|
Moon KW, Ryu JK. Current working models of SMC-driven DNA-loop extrusion. Biochem Soc Trans 2023; 51:1801-1810. [PMID: 37767565 DOI: 10.1042/bst20220898] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 09/17/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
Structural maintenance of chromosome (SMC) proteins play a key roles in the chromosome organization by condensing two meters of DNA into cell-sized structures considered as the SMC protein extrudes DNA loop. Recent sequencing-based high-throughput chromosome conformation capture technique (Hi-C) and single-molecule experiments have provided direct evidence of DNA-loop extrusion. However, the molecular mechanism by which SMCs extrude a DNA loop is still under debate. Here, we review DNA-loop extrusion studies with single-molecule assays and introduce recent structural studies of how the ATP-hydrolysis cycle is coupled to the conformational changes of SMCs for DNA-loop extrusion. In addition, we explain the conservation of the DNA-binding sites that are vital for dynamic DNA-loop extrusion by comparing Cryo-EM structures of SMC complexes. Based on this information, we compare and discuss four compelling working models that explain how the SMC complex extrudes a DNA loop.
Collapse
Affiliation(s)
- Kyoung-Wook Moon
- Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Je-Kyung Ryu
- Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| |
Collapse
|