1
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Raimer Young HM, Hou PC, Bartosik AR, Atkin ND, Wang L, Wang Z, Ratan A, Zang C, Wang YH. DNA fragility at topologically associated domain boundaries is promoted by alternative DNA secondary structure and topoisomerase II activity. Nucleic Acids Res 2024; 52:3837-3855. [PMID: 38452213 DOI: 10.1093/nar/gkae164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/03/2024] [Accepted: 02/23/2024] [Indexed: 03/09/2024] Open
Abstract
CCCTC-binding factor (CTCF) binding sites are hotspots of genome instability. Although many factors have been associated with CTCF binding site fragility, no study has integrated all fragility-related factors to understand the mechanism(s) of how they work together. Using an unbiased, genome-wide approach, we found that DNA double-strand breaks (DSBs) are enriched at strong, but not weak, CTCF binding sites in five human cell types. Energetically favorable alternative DNA secondary structures underlie strong CTCF binding sites. These structures coincided with the location of topoisomerase II (TOP2) cleavage complex, suggesting that DNA secondary structure acts as a recognition sequence for TOP2 binding and cleavage at CTCF binding sites. Furthermore, CTCF knockdown significantly increased DSBs at strong CTCF binding sites and at CTCF sites that are located at topologically associated domain (TAD) boundaries. TAD boundary-associated CTCF sites that lost CTCF upon knockdown displayed increased DSBs when compared to the gained sites, and those lost sites are overrepresented with G-quadruplexes, suggesting that the structures act as boundary insulators in the absence of CTCF, and contribute to increased DSBs. These results model how alternative DNA secondary structures facilitate recruitment of TOP2 to CTCF binding sites, providing mechanistic insight into DNA fragility at CTCF binding sites.
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Affiliation(s)
- Heather M Raimer Young
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Pei-Chi Hou
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Anna R Bartosik
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Naomi D Atkin
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
| | - Lixin Wang
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Zhenjia Wang
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA 22908-0717, USA
| | - Aakrosh Ratan
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA 22908-0717, USA
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- University of Virginia Comprehensive Cancer Center, Charlottesville, VA 22908, USA
| | - Chongzhi Zang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
- Center for Public Health Genomics, University of Virginia School of Medicine, Charlottesville, VA 22908-0717, USA
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- University of Virginia Comprehensive Cancer Center, Charlottesville, VA 22908, USA
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908-0733, USA
- University of Virginia Comprehensive Cancer Center, Charlottesville, VA 22908, USA
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2
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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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 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.
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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.
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3
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Santarelli P, Rosti V, Vivo M, Lanzuolo C. Chromatin organization of muscle stem cell. Curr Top Dev Biol 2024; 158:375-406. [PMID: 38670713 DOI: 10.1016/bs.ctdb.2024.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
The proper functioning of skeletal muscles is essential throughout life. A crucial crosstalk between the environment and several cellular mechanisms allows striated muscles to perform successfully. Notably, the skeletal muscle tissue reacts to an injury producing a completely functioning tissue. The muscle's robust regenerative capacity relies on the fine coordination between muscle stem cells (MuSCs or "satellite cells") and their specific microenvironment that dictates stem cells' activation, differentiation, and self-renewal. Critical for the muscle stem cell pool is a fine regulation of chromatin organization and gene expression. Acquiring a lineage-specific 3D genome architecture constitutes a crucial modulator of muscle stem cell function during development, in the adult stage, in physiological and pathological conditions. The context-dependent relationship between genome structure, such as accessibility and chromatin compartmentalization, and their functional effects will be analysed considering the improved 3D epigenome knowledge, underlining the intimate liaison between environmental encounters and epigenetics.
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Affiliation(s)
- Philina Santarelli
- INGM Istituto Nazionale Genetica Molecolare Romeo ed Enrica Invernizzi, Milan, Italy
| | - Valentina Rosti
- INGM Istituto Nazionale Genetica Molecolare Romeo ed Enrica Invernizzi, Milan, Italy; CNR Institute of Biomedical Technologies, Milan, Italy
| | - Maria Vivo
- Università degli studi di Salerno, Fisciano, Italy.
| | - Chiara Lanzuolo
- INGM Istituto Nazionale Genetica Molecolare Romeo ed Enrica Invernizzi, Milan, Italy; CNR Institute of Biomedical Technologies, Milan, Italy.
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4
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Richeldi M, Pobegalov G, Higashi TL, Gmurczyk K, Uhlmann F, Molodtsov MI. Mechanical disengagement of the cohesin ring. Nat Struct Mol Biol 2024; 31:23-31. [PMID: 37872232 DOI: 10.1038/s41594-023-01122-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 09/11/2023] [Indexed: 10/25/2023]
Abstract
Cohesin forms a proteinaceous ring that is thought to link sister chromatids by entrapping DNA and counteracting the forces generated by the mitotic spindle. Whether individual cohesins encircle both sister DNAs and how cohesin opposes spindle-generated forces remains unknown. Here we perform force measurements on individual yeast cohesin complexes either bound to DNA or holding together two DNAs. By covalently closing the hinge and Smc3Psm3-kleisin interfaces we find that the mechanical stability of the cohesin ring entrapping DNA is determined by the hinge domain. Forces of ~20 pN disengage cohesin at the hinge and release DNA, indicating that ~40 cohesin molecules are sufficient to counteract known spindle forces. Our findings provide a mechanical framework for understanding how cohesin interacts with sister chromatids and opposes the spindle-generated tension during mitosis, with implications for other force-generating chromosomal processes including transcription and DNA replication.
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Affiliation(s)
- Martina Richeldi
- Biophysics and Mechanobiology Laboratory, The Francis Crick Institute, London, UK
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
- Department of Physics and Astronomy, University College London, London, UK
| | - Georgii Pobegalov
- Biophysics and Mechanobiology Laboratory, The Francis Crick Institute, London, UK
- Department of Physics and Astronomy, University College London, London, UK
| | - Torahiko L Higashi
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
- Kamakura Research Laboratories, Chugai Pharmaceutical Co., Kamakura City, Japan
| | - Karolina Gmurczyk
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
| | - Maxim I Molodtsov
- Biophysics and Mechanobiology Laboratory, The Francis Crick Institute, London, UK.
- Department of Physics and Astronomy, University College London, London, UK.
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5
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Dekker C, Haering CH, Peters JM, Rowland BD. How do molecular motors fold the genome? Science 2023; 382:646-648. [PMID: 37943927 DOI: 10.1126/science.adi8308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
A potential mechanism of DNA loop extrusion by molecular motors is discussed.
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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
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6
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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7
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Kaur P, Lu X, Xu Q, Irvin EM, Pappas C, Zhang H, Finkelstein IJ, Shi Z, Tao YJ, Yu H, Wang H. High-speed AFM imaging reveals DNA capture and loop extrusion dynamics by cohesin-NIPBL. J Biol Chem 2023; 299:105296. [PMID: 37774974 PMCID: PMC10656236 DOI: 10.1016/j.jbc.2023.105296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 08/24/2023] [Accepted: 09/13/2023] [Indexed: 10/01/2023] Open
Abstract
3D chromatin organization plays a critical role in regulating gene expression, DNA replication, recombination, and repair. While initially discovered for its role in sister chromatid cohesion, emerging evidence suggests that the cohesin complex (SMC1, SMC3, RAD21, and SA1/SA2), facilitated by NIPBL, mediates topologically associating domains and chromatin loops through DNA loop extrusion. However, information on how conformational changes of cohesin-NIPBL drive its loading onto DNA, initiation, and growth of DNA loops is still lacking. In this study, high-speed atomic force microscopy imaging reveals that cohesin-NIPBL captures DNA through arm extension, assisted by feet (shorter protrusions), and followed by transfer of DNA to its lower compartment (SMC heads, RAD21, SA1, and NIPBL). While binding at the lower compartment, arm extension leads to the capture of a second DNA segment and the initiation of a DNA loop that is independent of ATP hydrolysis. The feet are likely contributed by the C-terminal domains of SA1 and NIPBL and can transiently bind to DNA to facilitate the loading of the cohesin complex onto DNA. Furthermore, high-speed atomic force microscopy imaging reveals distinct forward and reverse DNA loop extrusion steps by cohesin-NIPBL. These results advance our understanding of cohesin by establishing direct experimental evidence for a multistep DNA-binding mechanism mediated by dynamic protein conformational changes.
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Affiliation(s)
- Parminder Kaur
- Physics Department, North Carolina State University, Raleigh, North Carolina, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina, USA.
| | - Xiaotong Lu
- Department of BioSciences, Rice University, Houston, Texas, USA
| | - Qi Xu
- Westlake Laboratory of Life Sciences and Biomedicine, Westlake University, Hangzhou, Zhejiang Province, P.R. China; School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province, P.R. China
| | | | - Colette Pappas
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Hongshan Zhang
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Zhubing Shi
- Westlake Laboratory of Life Sciences and Biomedicine, Westlake University, Hangzhou, Zhejiang Province, P.R. China; School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province, P.R. China
| | - Yizhi Jane Tao
- Department of BioSciences, Rice University, Houston, Texas, USA
| | - Hongtao Yu
- Westlake Laboratory of Life Sciences and Biomedicine, Westlake University, Hangzhou, Zhejiang Province, P.R. China; School of Life Sciences, Westlake University, Hangzhou, Zhejiang Province, P.R. China
| | - Hong Wang
- Physics Department, North Carolina State University, Raleigh, North Carolina, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina, USA; Toxicology Program, North Carolina State University, Raleigh, North Carolina, USA.
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8
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [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.
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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
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9
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Chen J, Floyd EN, Dawson DS, Rankin S. Cornelia de Lange Syndrome mutations in SMC1A cause cohesion defects in yeast. Genetics 2023; 225:iyad159. [PMID: 37650609 PMCID: PMC10550314 DOI: 10.1093/genetics/iyad159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 08/07/2023] [Accepted: 08/11/2023] [Indexed: 09/01/2023] Open
Abstract
Cornelia de Lange Syndrome (CdLS) is a developmental disorder characterized by limb truncations, craniofacial abnormalities, and cognitive delays. CdLS is caused mainly by mutations in genes encoding subunits or regulators of the cohesin complex. Cohesin plays 2 distinct roles in chromosome dynamics as follows: it promotes looping, organization, and compaction of individual chromosomes, and it holds newly replicated sister chromatids together until cell division. CdLS-associated mutations result in altered gene expression likely by affecting chromosome architecture. Whether CdLS mutations cause phenotypes through impact on sister chromatid cohesion is less clear. Here, we show that CdLS-associated mutations introduced into the SMC1A gene of budding yeast had measurable impacts on sister chromatid cohesion, mitotic progression, and DNA damage sensitivity. These data suggest that sister chromatid cohesion-related defects may contribute to phenotypes seen in CdLS affected individuals.
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Affiliation(s)
- Jingrong Chen
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th St. Oklahoma City, OK 73104, USA
| | - Erin N Floyd
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th St. Oklahoma City, OK 73104, USA
| | - Dean S Dawson
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th St. Oklahoma City, OK 73104, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Susannah Rankin
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825 NE 13th St. Oklahoma City, OK 73104, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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10
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Alonso-Gil D, Losada A. NIPBL and cohesin: new take on a classic tale. Trends Cell Biol 2023; 33:860-871. [PMID: 37062615 DOI: 10.1016/j.tcb.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 04/18/2023]
Abstract
Cohesin folds the genome in dynamic chromatin loops and holds the sister chromatids together. NIPBLScc2 is currently considered the cohesin loader, a role that may need reevaluation. NIPBL activates the cohesin ATPase, which is required for topological entrapment of sister DNAs and to fuel DNA loop extrusion, but is not required for chromatin association. Mechanistic dissection of these processes suggests that both NIPBL and the cohesin STAG subunit bind DNA. NIPBL also regulates conformational switches of the complex. Interactions of NIPBL with chromatin factors, including remodelers, replication proteins, and the transcriptional machinery, affect cohesin loading and distribution. Here, we discuss recent research addressing how NIPBL modulates cohesin activities and how its mutation causes a developmental disorder, Cornelia de Lange Syndrome (CdLS).
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Affiliation(s)
- Dácil Alonso-Gil
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Ana Losada
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
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11
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Scadden AW, Graybill AS, Hull-Crew C, Lundberg TJ, Lande NM, Klocko AD. Histone deacetylation and cytosine methylation compartmentalize heterochromatic regions in the genome organization of Neurospora crassa. bioRxiv 2023:2023.07.03.547530. [PMID: 37461718 PMCID: PMC10349943 DOI: 10.1101/2023.07.03.547530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Chromosomes must correctly fold in eukaryotic nuclei for proper genome function. Eukaryotic organisms hierarchically organize their genomes, including in the fungus Neurospora crassa, where chromatin fiber loops compact into Topologically Associated Domain (TAD)-like structures formed by heterochromatic region aggregation. However, insufficient data exists on how histone post-translational modifications, including acetylation, affect genome organization. In Neurospora, the HCHC complex (comprised of the proteins HDA-1, CDP-2, HP1, and CHAP) deacetylates heterochromatic nucleosomes, as loss of individual HCHC members increases centromeric acetylation and alters the methylation of cytosines in DNA. Here, we assess if the HCHC complex affects genome organization by performing Hi-C in strains deleted of the cdp-2 or chap genes. CDP-2 loss increases intra- and inter-chromosomal heterochromatic region interactions, while loss of CHAP decreases heterochromatic region compaction. Individual HCHC mutants exhibit different patterns of histone post-translational modifications genome-wide: without CDP-2, heterochromatic H4K16 acetylation is increased, yet smaller heterochromatic regions lose H3K9 trimethylation and gain inter-heterochromatic region interactions; CHAP loss produces minimal acetylation changes but increases heterochromatic H3K9me3 enrichment. Loss of both CDP-2 and the DIM-2 DNA methyltransferase causes extensive genome disorder, as heterochromatic-euchromatic contacts increase despite additional H3K9me3 enrichment. Our results highlight how the increased cytosine methylation in HCHC mutants ensures genome compartmentalization when heterochromatic regions become hyperacetylated without HDAC activity.
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Affiliation(s)
- Ashley W. Scadden
- University of Colorado Colorado Springs, Department of Chemistry & Biochemistry, Colorado Springs, CO 80918, USA
| | - Alayne S. Graybill
- University of Colorado Colorado Springs, Department of Chemistry & Biochemistry, Colorado Springs, CO 80918, USA
| | - Clayton Hull-Crew
- University of Colorado Colorado Springs, Department of Chemistry & Biochemistry, Colorado Springs, CO 80918, USA
| | - Tiffany J. Lundberg
- University of Colorado Colorado Springs, Department of Chemistry & Biochemistry, Colorado Springs, CO 80918, USA
| | - Nickolas M. Lande
- University of Colorado Colorado Springs, Department of Chemistry & Biochemistry, Colorado Springs, CO 80918, USA
| | - Andrew D. Klocko
- University of Colorado Colorado Springs, Department of Chemistry & Biochemistry, Colorado Springs, CO 80918, USA
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12
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Kaushik A, Than T, Petela NJ, Voulgaris M, Percival C, Daniels P, Rafferty JB, Nasmyth KA, Hu B. Conformational dynamics of cohesin/Scc2 loading complex are regulated by Smc3 acetylation and ATP binding. Nat Commun 2023; 14:5929. [PMID: 37739959 PMCID: PMC10516938 DOI: 10.1038/s41467-023-41596-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 09/11/2023] [Indexed: 09/24/2023] Open
Abstract
The ring-shaped cohesin complex is a key player in sister chromatid cohesion, DNA repair, and gene transcription. The loading of cohesin to chromosomes requires the loader Scc2 and is regulated by ATP. This process is hindered by Smc3 acetylation. However, the molecular mechanism underlying this inhibition remains mysterious. Here, using Saccharomyces cerevisiae as a model system, we identify a novel configuration of Scc2 with pre-engaged cohesin and reveal dynamic conformations of the cohesin/Scc2 complex in the loading reaction. We demonstrate that Smc3 acetylation blocks the association of Scc2 with pre-engaged cohesin by impairing the interaction of Scc2 with Smc3's head. Lastly, we show that ATP binding induces the cohesin/Scc2 complex to clamp DNA by promoting the interaction between Scc2 and Smc3 coiled coil. Our results illuminate a dynamic reconfiguration of the cohesin/Scc2 complex during loading and indicate how Smc3 acetylation and ATP regulate this process.
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Affiliation(s)
- Aditi Kaushik
- The Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK
| | - Thane Than
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Naomi J Petela
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | | | - Charlotte Percival
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Peter Daniels
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - John B Rafferty
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Kim A Nasmyth
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Bin Hu
- The Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK.
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13
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Nagasaka K, Davidson IF, Stocsits RR, Tang W, Wutz G, Batty P, Panarotto M, Litos G, Schleiffer A, Gerlich DW, Peters JM. Cohesin mediates DNA loop extrusion and sister chromatid cohesion by distinct mechanisms. Mol Cell 2023; 83:3049-3063.e6. [PMID: 37591243 DOI: 10.1016/j.molcel.2023.07.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 05/28/2023] [Accepted: 07/25/2023] [Indexed: 08/19/2023]
Abstract
Cohesin connects CTCF-binding sites and other genomic loci in cis to form chromatin loops and replicated DNA molecules in trans to mediate sister chromatid cohesion. Whether cohesin uses distinct or related mechanisms to perform these functions is unknown. Here, we describe a cohesin hinge mutant that can extrude DNA into loops but is unable to mediate cohesion in human cells. Our results suggest that the latter defect arises during cohesion establishment. The observation that cohesin's cohesion and loop extrusion activities can be partially separated indicates that cohesin uses distinct mechanisms to perform these two functions. Unexpectedly, the same hinge mutant can also not be stopped by CTCF boundaries as well as wild-type cohesin. This suggests that cohesion establishment and cohesin's interaction with CTCF boundaries depend on related mechanisms and raises the possibility that both require transient hinge opening to entrap DNA inside the cohesin ring.
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Affiliation(s)
- Kota Nagasaka
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Roman R Stocsits
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Wen Tang
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Gordana Wutz
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Paul Batty
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, Vienna 1030, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna 1030, Austria
| | - Melanie Panarotto
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna 1030, Austria
| | - Gabriele Litos
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria
| | - Alexander Schleiffer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria; Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, Vienna 1030, Austria
| | - Daniel W Gerlich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, Vienna 1030, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna 1030, Austria.
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14
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Wright NE, Mandal M, Clark MR. Molecular mechanisms insulating proliferation from genotoxic stress in B lymphocytes. Trends Immunol 2023; 44:668-677. [PMID: 37573227 PMCID: PMC10530527 DOI: 10.1016/j.it.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/25/2023] [Accepted: 06/30/2023] [Indexed: 08/14/2023]
Abstract
In mammals, B cells strictly segregate proliferation from somatic mutation as they develop within the bone marrow and then mature through germinal centers (GCs) in the periphery. Failure to do so risks autoimmunity and neoplastic transformation. Recent work has described how B cell progenitors transition between proliferation and mutation via cytokine signaling pathways, epigenetic chromatin regulation, and remodeling of 3D chromatin conformation. We propose a three-zone model of the GC that describes how proliferation and mutation are regulated. Using this model, we consider how recent mechanistic discoveries in B cell progenitors inform models of GC B cell function and reveal fundamental mechanisms underpinning humoral immunity, autoimmunity, and lymphomagenesis.
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Affiliation(s)
- Nathaniel E Wright
- Department of Medicine, Section of Rheumatology, and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL, USA
| | - Malay Mandal
- Department of Medicine, Section of Rheumatology, and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL, USA
| | - Marcus R Clark
- Department of Medicine, Section of Rheumatology, and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL, USA.
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15
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Irvin EM, Wang H. Single-molecule imaging of genome maintenance proteins encountering specific DNA sequences and structures. DNA Repair (Amst) 2023; 128:103528. [PMID: 37392578 PMCID: PMC10989508 DOI: 10.1016/j.dnarep.2023.103528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 06/08/2023] [Accepted: 06/21/2023] [Indexed: 07/03/2023]
Abstract
DNA repair pathways are tightly regulated processes that recognize specific hallmarks of DNA damage and coordinate lesion repair through discrete mechanisms, all within the context of a three-dimensional chromatin landscape. Dysregulation or malfunction of any one of the protein constituents in these pathways can contribute to aging and a variety of diseases. While the collective action of these many proteins is what drives DNA repair on the organismal scale, it is the interactions between individual proteins and DNA that facilitate each step of these pathways. In much the same way that ensemble biochemical techniques have characterized the various steps of DNA repair pathways, single-molecule imaging (SMI) approaches zoom in further, characterizing the individual protein-DNA interactions that compose each pathway step. SMI techniques offer the high resolving power needed to characterize the molecular structure and functional dynamics of individual biological interactions on the nanoscale. In this review, we highlight how our lab has used SMI techniques - traditional atomic force microscopy (AFM) imaging in air, high-speed AFM (HS-AFM) in liquids, and the DNA tightrope assay - over the past decade to study protein-nucleic acid interactions involved in DNA repair, mitochondrial DNA replication, and telomere maintenance. We discuss how DNA substrates containing specific DNA sequences or structures that emulate DNA repair intermediates or telomeres were generated and validated. For each highlighted project, we discuss novel findings made possible by the spatial and temporal resolution offered by these SMI techniques and unique DNA substrates.
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Affiliation(s)
| | - Hong Wang
- Toxicology Program, North Carolina State University, Raleigh, NC, USA; Physics Department, North Carolina State University, Raleigh, NC, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, USA.
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16
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Pobegalov G, Chu LY, Peters JM, Molodtsov MI. Single cohesin molecules generate force by two distinct mechanisms. Nat Commun 2023; 14:3946. [PMID: 37402740 DOI: 10.1038/s41467-023-39696-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/23/2023] [Indexed: 07/06/2023] Open
Abstract
Spatial organization of DNA is facilitated by cohesin protein complexes that move on DNA and extrude DNA loops. How cohesin works mechanistically as a molecular machine is poorly understood. Here, we measure mechanical forces generated by conformational changes in single cohesin molecules. We show that bending of SMC coiled coils is driven by random thermal fluctuations leading to a ~32 nm head-hinge displacement that resists forces up to 1 pN; ATPase head engagement occurs in a single step of ~10 nm and is driven by an ATP dependent head-head movement, resisting forces up to 15 pN. Our molecular dynamic simulations show that the energy of head engagement can be stored in a mechanically strained conformation of NIPBL and released during disengagement. These findings reveal how single cohesin molecules generate force by two distinct mechanisms. We present a model, which proposes how this ability may power different aspects of cohesin-DNA interaction.
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Affiliation(s)
- Georgii Pobegalov
- The Francis Crick Institute, London, NW1 1AT, UK
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
| | - Lee-Ya Chu
- The Francis Crick Institute, London, NW1 1AT, UK
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Vienna, 1030, Austria
| | - Maxim I Molodtsov
- The Francis Crick Institute, London, NW1 1AT, UK.
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Vienna, 1030, Austria.
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17
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Chan B, Rubinstein M. Theory of chromatin organization maintained by active loop extrusion. Proc Natl Acad Sci U S A 2023; 120:e2222078120. [PMID: 37253009 PMCID: PMC10266055 DOI: 10.1073/pnas.2222078120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/13/2023] [Indexed: 06/01/2023] Open
Abstract
The active loop extrusion hypothesis proposes that chromatin threads through the cohesin protein complex into progressively larger loops until reaching specific boundary elements. We build upon this hypothesis and develop an analytical theory for active loop extrusion which predicts that loop formation probability is a nonmonotonic function of loop length and describes chromatin contact probabilities. We validate our model with Monte Carlo and hybrid Molecular Dynamics-Monte Carlo simulations and demonstrate that our theory recapitulates experimental chromatin conformation capture data. Our results support active loop extrusion as a mechanism for chromatin organization and provide an analytical description of chromatin organization that may be used to specifically modify chromatin contact probabilities.
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Affiliation(s)
- Brian Chan
- Department of Biomedical Engineering, Duke University, Durham, NC27708
| | - Michael Rubinstein
- Department of Biomedical Engineering, Duke University, Durham, NC27708
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC27708
- Department of Chemistry, Duke University, Durham, NC27708
- Department of Physics, Duke University, Durham, NC27708
- Institute for Chemical Reaction Design and Discovery (World Premier International Research Center Initiative-ICReDD), Hokkaido University, Sapporo001-0021, Japan
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18
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Abstract
Structural maintenance of chromosomes (SMC) complexes guard and organize the three-dimensional structure of chromosomal DNA across the tree of life. Many SMC functions can be explained by an inherent motor activity that extrudes large DNA loops while the complexes move along their substrate. Here, we review recent structural insights into the architecture and conservation of these molecular machines, their interaction with DNA, and the conformational changes that are linked to their ATP hydrolysis cycle.
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Affiliation(s)
- Frank Bürmann
- MRC Laboratory of Molecular Biology, Structural Studies Division, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Structural Studies Division, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK.
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19
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Abstract
Structural maintenance of chromosomes (SMC) complexes are ubiquitous genome regulators with a wide range of functions. Among the three types of SMC complexes in eukaryotes, cohesin and condensin fold the genome into different domains and structures, while Smc5/6 plays direct roles in promoting chromosomal replication and repair and in restraining pathogenic viral extra-chromosomal DNA. The importance of Smc5/6 for growth, genotoxin resistance and host defense across species is highlighted by its involvement in disease prevention in plants and animals. Accelerated progress in recent years, including structural and single-molecule studies, has begun to provide greater insights into the mechanisms underlying Smc5/6 functions. Here we integrate a broad range of recent studies on Smc5/6 to identify emerging features of this unique SMC complex and to explain its diverse cellular functions and roles in disease pathogenesis. We also highlight many key areas requiring further investigation for achieving coherent views of Smc5/6-driven mechanisms.
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Affiliation(s)
- Xiao P Peng
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xiaolan Zhao
- Molecular Biology Program, Sloan Kettering Cancer Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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20
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Barth R, Pradhan B, Kim E, Davidson IF, van der Torre J, Peters JM, Dekker C. Testing pseudotopological and nontopological models for SMC-driven DNA loop extrusion against roadblock-traversal experiments. Sci Rep 2023; 13:8100. [PMID: 37208374 DOI: 10.1038/s41598-023-35359-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/17/2023] [Indexed: 05/21/2023] Open
Abstract
DNA loop extrusion by structural-maintenance-of-chromosome (SMC) complexes has emerged as a primary organizing principle for chromosomes. The mechanism by which SMC motor proteins extrude DNA loops is still unresolved and much debated. The ring-like structure of SMC complexes prompted multiple models where the extruded DNA is topologically or pseudotopologically entrapped within the ring during loop extrusion. However, recent experiments showed the passage of roadblocks much bigger than the SMC ring size, suggesting a nontopological mechanism. Recently, attempts were made to reconcile the observed passage of large roadblocks with a pseudotopological mechanism. Here we examine the predictions of these pseudotopological models and find that they are not consistent with new experimental data on SMC roadblock encounters. Particularly, these models predict the formation of two loops and that roadblocks will reside near the stem of the loop upon encounter-both in contrast to experimental observations. Overall, the experimental data reinforce the notion of a nontopological mechanism for extrusion of DNA.
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Affiliation(s)
- Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
| | - Biswajit Pradhan
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
- Max-Planck Institute of Biophysics, Frankfurt Am Main, Germany
| | - Eugene Kim
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
- Max-Planck Institute of Biophysics, Frankfurt Am Main, Germany
| | - Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, The Netherlands.
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21
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Uyehara CM, Apostolou E. 3D enhancer-promoter interactions and multi-connected hubs: Organizational principles and functional roles. Cell Rep 2023; 42:112068. [PMID: 37059094 PMCID: PMC10556201 DOI: 10.1016/j.celrep.2023.112068] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/25/2022] [Accepted: 01/20/2023] [Indexed: 04/16/2023] Open
Abstract
The spatiotemporal control of gene expression is dependent on the activity of cis-acting regulatory sequences, called enhancers, which regulate target genes over variable genomic distances and, often, by skipping intermediate promoters, suggesting mechanisms that control enhancer-promoter communication. Recent genomics and imaging technologies have revealed highly complex enhancer-promoter interaction networks, whereas advanced functional studies have started interrogating the forces behind the physical and functional communication among multiple enhancers and promoters. In this review, we first summarize our current understanding of the factors involved in enhancer-promoter communication, with a particular focus on recent papers that have revealed new layers of complexities to old questions. In the second part of the review, we focus on a subset of highly connected enhancer-promoter "hubs" and discuss their potential functions in signal integration and gene regulation, as well as the putative factors that might determine their dynamics and assembly.
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Affiliation(s)
- Christopher M Uyehara
- Sanford I. Weill Department of Medicine, Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Effie Apostolou
- Sanford I. Weill Department of Medicine, Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA.
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22
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Ortabozkoyun H, Huang PY, Cho H, Tsirigos A, Mazzoni E, Reinberg D. Novel Chromatin Insulating Activities Uncovered upon Eliminating Known Insulators in vivo. bioRxiv 2023:2023.04.25.538167. [PMID: 37162865 PMCID: PMC10168243 DOI: 10.1101/2023.04.25.538167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
CCCTC-binding factor (CTCF) and MAZ are recognized insulators required for shielding repressed posterior genes from active anterior genes within the Hox clusters during motor neuron (MN) differentiation. CTCF and MAZ interact independently with cohesin and regulate three-dimensional genome organization. Here, we followed cohesin re-location upon CTCF and MAZ depletion in mouse embryonic stem cells (mESCs) to identify novel insulators. Cohesin relocated to DNA motifs for various transcription factors, including PATZ1 and other zinc finger proteins (ZNFs). Moreover, PATZ1 and ZNFs co-localized with CTCF, MAZ, and cohesin with apparent overlapping specificity as dictated by the site to be insulated. Similar to CTCF and MAZ, PATZ1 interacted with RAD21. Patz1 KO mESCs exhibited altered global gene expression. While the absence of MAZ impacts anterior CTCF-boundaries as shown previously 1 , Patz1 KO led to derepression of posterior Hox genes, resulting in cervicothoracic transformation of motor neuron (MN) fate during differentiation. These findings point to a varied, combinatorial binding of known and newly defined accessory factors as being critical for positional identity and cellular fate determination during differentiation.
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23
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Tiukacheva EA, Ulianov SV, Karpukhina A, Razin SV, Vassetzky Y. 3D genome alterations and editing in pathology. Mol Ther 2023; 31:924-933. [PMID: 36755493 PMCID: PMC10124079 DOI: 10.1016/j.ymthe.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/07/2022] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
The human genome is folded into a multi-level 3D structure that controls many nuclear functions including gene expression. Recently, alterations in 3D genome organization were associated with several genetic diseases and cancer. As a consequence, experimental approaches are now being developed to modify the global 3D genome organization and that of specific loci. Here, we discuss emerging experimental approaches of 3D genome editing that may prove useful in biomedicine.
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Affiliation(s)
- Eugenia A Tiukacheva
- CNRS UMR9018, Institut Gustave Roussy, 94805 Villejuif, France; Institute of Gene Biology, Moscow 119334, Russia; Moscow Institute of Physics and Technology, Moscow 141700, Russia; Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia; Koltzov Institute of Developmental Biology, Moscow 119334, Russia
| | - Sergey V Ulianov
- Institute of Gene Biology, Moscow 119334, Russia; Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Anna Karpukhina
- CNRS UMR9018, Institut Gustave Roussy, 94805 Villejuif, France; Koltzov Institute of Developmental Biology, Moscow 119334, Russia
| | - Sergey V Razin
- Institute of Gene Biology, Moscow 119334, Russia; Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Yegor Vassetzky
- CNRS UMR9018, Institut Gustave Roussy, 94805 Villejuif, France; Koltzov Institute of Developmental Biology, Moscow 119334, Russia.
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24
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Horsfield JA. Full circle: a brief history of cohesin and the regulation of gene expression. FEBS J 2023; 290:1670-1687. [PMID: 35048511 DOI: 10.1111/febs.16362] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/21/2021] [Accepted: 01/18/2022] [Indexed: 12/17/2022]
Abstract
The cohesin complex has a range of crucial functions in the cell. Cohesin is essential for mediating chromatid cohesion during mitosis, for repair of double-strand DNA breaks, and for control of gene transcription. This last function has been the subject of intense research ever since the discovery of cohesin's role in the long-range regulation of the cut gene in Drosophila. Subsequent research showed that the expression of some genes is exquisitely sensitive to cohesin depletion, while others remain relatively unperturbed. Sensitivity to cohesin depletion is also remarkably cell type- and/or condition-specific. The relatively recent discovery that cohesin is integral to forming chromatin loops via loop extrusion should explain much of cohesin's gene regulatory properties, but surprisingly, loop extrusion has failed to identify a 'one size fits all' mechanism for how cohesin controls gene expression. This review will illustrate how early examples of cohesin-dependent gene expression integrate with later work on cohesin's role in genome organization to explain mechanisms by which cohesin regulates gene expression.
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Affiliation(s)
- Julia A Horsfield
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
- Genetics Otago Research Centre, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, New Zealand
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25
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Boardman K, Xiang S, Chatterjee F, Mbonu U, Guacci V, Koshland D. A model for Scc2p stimulation of cohesin's ATPase and its inhibition by acetylation of Smc3p. Genes Dev 2023; 37:277-290. [PMID: 37055084 PMCID: PMC10153460 DOI: 10.1101/gad.350278.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/09/2023] [Indexed: 04/15/2023]
Abstract
The evolutionarily conserved cohesin complex mediates sister chromatid cohesion and facilitates mitotic chromosome condensation, DNA repair, and transcription regulation. These biological functions require cohesin's two ATPases, formed by the Smc1p and Smc3p subunits. Cohesin's ATPase activity is stimulated by the Scc2p auxiliary factor. This stimulation is inhibited by Eco1p acetylation of Smc3p at an interface with Scc2p. It was unclear how cohesin's ATPase activity is stimulated by Scc2p or how acetylation inhibits Scc2p, given that the acetylation site is distal to cohesin's ATPase active sites. Here, we identify mutations in budding yeast that suppressed the in vivo defects caused by Smc3p acetyl-mimic and acetyl-defective mutations. We provide compelling evidence that Scc2p activation of cohesin ATPase depends on an interface between Scc2p and a region of Smc1p proximal to cohesin's Smc3p ATPase active site. Furthermore, substitutions at this interface increase or decrease ATPase activity to overcome ATPase modulation by acetyl-mimic and acetyl-null mutations. Using these observations and an existing cryo-EM structure, we propose a model for regulating cohesin ATPase activity. We suggest that Scc2p binding to Smc1p causes the adjacent Smc1p residues and ATP to shift, stimulating Smc3p's ATPase. This stimulatory shift is inhibited through acetylation of the distal Scc2p-Smc3p interface.
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Affiliation(s)
- Kevin Boardman
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA
| | - Siheng Xiang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA
| | - Fiona Chatterjee
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA
| | - Udochi Mbonu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA
| | - Vincent Guacci
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA
| | - Douglas Koshland
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA
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26
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Davidson IF, Barth R, Zaczek M, van der Torre J, Tang W, Nagasaka K, Janissen R, Kerssemakers J, Wutz G, Dekker C, Peters JM. CTCF is a DNA-tension-dependent barrier to cohesin-mediated loop extrusion. Nature 2023; 616:822-827. [PMID: 37076620 PMCID: PMC10132984 DOI: 10.1038/s41586-023-05961-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 03/16/2023] [Indexed: 04/21/2023]
Abstract
In eukaryotes, genomic DNA is extruded into loops by cohesin1. By restraining this process, the DNA-binding protein CCCTC-binding factor (CTCF) generates topologically associating domains (TADs)2,3 that have important roles in gene regulation and recombination during development and disease1,4-7. How CTCF establishes TAD boundaries and to what extent these are permeable to cohesin is unclear8. Here, to address these questions, we visualize interactions of single CTCF and cohesin molecules on DNA in vitro. We show that CTCF is sufficient to block diffusing cohesin, possibly reflecting how cohesive cohesin accumulates at TAD boundaries, and is also sufficient to block loop-extruding cohesin, reflecting how CTCF establishes TAD boundaries. CTCF functions asymmetrically, as predicted; however, CTCF is dependent on DNA tension. Moreover, CTCF regulates cohesin's loop-extrusion activity by changing its direction and by inducing loop shrinkage. Our data indicate that CTCF is not, as previously assumed, simply a barrier to cohesin-mediated loop extrusion but is an active regulator of this process, whereby the permeability of TAD boundaries can be modulated by DNA tension. These results reveal mechanistic principles of how CTCF controls loop extrusion and genome architecture.
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Affiliation(s)
- Iain F Davidson
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Maciej Zaczek
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
- Children's Cancer Research Institute, St Anna Kinderkrebsforschung, Vienna, Austria
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Wen Tang
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Kota Nagasaka
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Jacob Kerssemakers
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Gordana Wutz
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands.
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria.
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27
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Shin H, Kim Y. Regulation of loop extrusion on the interphase genome. Crit Rev Biochem Mol Biol 2023; 58:1-18. [PMID: 36921088 DOI: 10.1080/10409238.2023.2182273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
In the human cell nucleus, dynamically organized chromatin is the substrate for gene regulation, DNA replication, and repair. A central mechanism of DNA loop formation is an ATPase motor cohesin-mediated loop extrusion. The cohesin complexes load and unload onto the chromosome under the control of other regulators that physically interact and affect motor activity. Regulation of the dynamic loading cycle of cohesin influences not only the chromatin structure but also genome-associated human disorders and aging. This review focuses on the recently spotlighted genome organizing factors and the mechanism by which their dynamic interactions shape the genome architecture in interphase.
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Affiliation(s)
- Hyogyung Shin
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Yoori Kim
- Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea.,New Biology Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
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28
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Alonso-Gil D, Cuadrado A, Giménez-Llorente D, Rodríguez-Corsino M, Losada A. Different NIPBL requirements of cohesin-STAG1 and cohesin-STAG2. Nat Commun 2023; 14:1326. [PMID: 36898992 PMCID: PMC10006224 DOI: 10.1038/s41467-023-36900-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/22/2023] [Indexed: 03/12/2023] Open
Abstract
Cohesin organizes the genome through the formation of chromatin loops. NIPBL activates cohesin's ATPase and is essential for loop extrusion, but its requirement for cohesin loading is unclear. Here we have examined the effect of reducing NIPBL levels on the behavior of the two cohesin variants carrying STAG1 or STAG2 by combining a flow cytometry assay to measure chromatin-bound cohesin with analyses of its genome-wide distribution and genome contacts. We show that NIPBL depletion results in increased cohesin-STAG1 on chromatin that further accumulates at CTCF positions while cohesin-STAG2 diminishes genome-wide. Our data are consistent with a model in which NIPBL may not be required for chromatin association of cohesin but it is for loop extrusion, which in turn facilitates stabilization of cohesin-STAG2 at CTCF positions after being loaded elsewhere. In contrast, cohesin-STAG1 binds chromatin and becomes stabilized at CTCF sites even under low NIPBL levels, but genome folding is severely impaired.
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Affiliation(s)
- Dácil Alonso-Gil
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Ana Cuadrado
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Daniel Giménez-Llorente
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Miriam Rodríguez-Corsino
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Ana Losada
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
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29
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Kabirova E, Nurislamov A, Shadskiy A, Smirnov A, Popov A, Salnikov P, Battulin N, Fishman V. Function and Evolution of the Loop Extrusion Machinery in Animals. Int J Mol Sci 2023; 24:ijms24055017. [PMID: 36902449 PMCID: PMC10003631 DOI: 10.3390/ijms24055017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/25/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Structural maintenance of chromosomes (SMC) complexes are essential proteins found in genomes of all cellular organisms. Essential functions of these proteins, such as mitotic chromosome formation and sister chromatid cohesion, were discovered a long time ago. Recent advances in chromatin biology showed that SMC proteins are involved in many other genomic processes, acting as active motors extruding DNA, which leads to the formation of chromatin loops. Some loops formed by SMC proteins are highly cell type and developmental stage specific, such as SMC-mediated DNA loops required for VDJ recombination in B-cell progenitors, or dosage compensation in Caenorhabditis elegans and X-chromosome inactivation in mice. In this review, we focus on the extrusion-based mechanisms that are common for multiple cell types and species. We will first describe an anatomy of SMC complexes and their accessory proteins. Next, we provide biochemical details of the extrusion process. We follow this by the sections describing the role of SMC complexes in gene regulation, DNA repair, and chromatin topology.
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Affiliation(s)
- Evelyn Kabirova
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Artem Nurislamov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Artem Shadskiy
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Alexander Smirnov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Andrey Popov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Pavel Salnikov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Nariman Battulin
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Veniamin Fishman
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
- Artificial Intelligence Research Institute (AIRI), 121108 Moscow, Russia
- Correspondence:
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30
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Zhang Y, Ma M, Liu M, Sun A, Zheng X, Liu K, Yin C, Li C, Jiang C, Tu X, Fang Y. Histone H2A monoubiquitination marks are targeted to specific sites by cohesin subunits in Arabidopsis. Nat Commun 2023; 14:1209. [PMID: 36869051 PMCID: PMC9984397 DOI: 10.1038/s41467-023-36788-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 02/16/2023] [Indexed: 03/05/2023] Open
Abstract
Histone H2A monoubiquitination (H2Aub1) functions as a conserved posttranslational modification in eukaryotes to maintain gene expression and guarantee cellular identity. Arabidopsis H2Aub1 is catalyzed by the core components AtRING1s and AtBMI1s of polycomb repressive complex 1 (PRC1). Because PRC1 components lack known DNA binding domains, it is unclear how H2Aub1 is established at specific genomic locations. Here, we show that the Arabidopsis cohesin subunits AtSYN4 and AtSCC3 interact with each other, and AtSCC3 binds to AtBMI1s. H2Aub1 levels are reduced in atsyn4 mutant or AtSCC3 artificial microRNA knockdown plants. ChIP-seq assays indicate that most binding events of AtSYN4 and AtSCC3 are associated with H2Aub1 along the genome where transcription is activated independently of H3K27me3. Finally, we show that AtSYN4 binds directly to the G-box motif and directs H2Aub1 to these sites. Our study thus reveals a mechanism for cohesin-mediated recruitment of AtBMI1s to specific genomic loci to mediate H2Aub1.
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Affiliation(s)
- Yu Zhang
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Min Ma
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Meng Liu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Life Sciences and Technology, Tongji University, 200065, Shanghai, China
| | - Aiqing Sun
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Xiaoyun Zheng
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Kunpeng Liu
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Chunmei Yin
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Chuanshun Li
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Cizhong Jiang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Life Sciences and Technology, Tongji University, 200065, Shanghai, China.
| | - Xiaoyu Tu
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China.
| | - Yuda Fang
- Joint Center for Single Cell Biology, School of Agriculture and Biology, Shanghai Jiao Tong University, 200240, Shanghai, China.
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31
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Moeckel C, Zaravinos A, Georgakopoulos-Soares I. Strand Asymmetries Across Genomic Processes. Comput Struct Biotechnol J 2023; 21:2036-2047. [PMID: 36968020 PMCID: PMC10030826 DOI: 10.1016/j.csbj.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/08/2023] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
Across biological systems, a number of genomic processes, including transcription, replication, DNA repair, and transcription factor binding, display intrinsic directionalities. These directionalities are reflected in the asymmetric distribution of nucleotides, motifs, genes, transposon integration sites, and other functional elements across the two complementary strands. Strand asymmetries, including GC skews and mutational biases, have shaped the nucleotide composition of diverse organisms. The investigation of strand asymmetries often serves as a method to understand underlying biological mechanisms, including protein binding preferences, transcription factor interactions, retrotransposition, DNA damage and repair preferences, transcription-replication collisions, and mutagenesis mechanisms. Research into this subject also enables the identification of functional genomic sites, such as replication origins and transcription start sites. Improvements in our ability to detect and quantify DNA strand asymmetries will provide insights into diverse functionalities of the genome, the contribution of different mutational mechanisms in germline and somatic mutagenesis, and our knowledge of genome instability and evolution, which all have significant clinical implications in human disease, including cancer. In this review, we describe key developments that have been made across the field of genomic strand asymmetries, as well as the discovery of associated mechanisms.
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Affiliation(s)
- Camille Moeckel
- Institute for Personalized Medicine, Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Apostolos Zaravinos
- Department of Life Sciences, European University Cyprus, Diogenis Str., 6, Nicosia 2404, Cyprus
- Cancer Genetics, Genomics and Systems Biology laboratory, Basic and Translational Cancer Research Center (BTCRC), Nicosia 1516, Cyprus
- Corresponding author at: Department of Life Sciences, European University Cyprus, Diogenis Str., 6, Nicosia 2404, Cyprus.
| | - Ilias Georgakopoulos-Soares
- Institute for Personalized Medicine, Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
- Corresponding author.
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32
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Yeo SJ, Ying C, Fullwood MJ, Tergaonkar V. Emerging regulatory mechanisms of noncoding RNAs in topologically associating domains. Trends Genet 2023; 39:217-232. [PMID: 36642680 DOI: 10.1016/j.tig.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 12/17/2022] [Accepted: 12/20/2022] [Indexed: 01/15/2023]
Abstract
Topologically associating domains (TADs) are integral to spatial genome organization, instructing gene expression, and cell fate. Recently, several advances have uncovered roles for noncoding RNAs (ncRNAs) in the regulation of the form and function of mammalian TADs. Phase separation has also emerged as a potential arbiter of ncRNAs in the regulation of TADs. In this review we discuss the implications of these novel findings in relation to how ncRNAs might structurally and functionally regulate TADs from two perspectives: moderating loop extrusion through interactions with architectural proteins, and facilitating TAD phase separation. Additionally, we propose future studies and directions to investigate these phenomena.
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Affiliation(s)
- Samuel Jianjie Yeo
- Laboratory of NFκB Signaling, Institute of Molecular Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University (NTU), Singapore 308232, Singapore
| | - Chen Ying
- Laboratory of NFκB Signaling, Institute of Molecular Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore
| | - Melissa Jane Fullwood
- Cancer Science Institute of Singapore, Centre for Translational Medicine, National University of Singapore, Singapore 117599, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.
| | - Vinay Tergaonkar
- Laboratory of NFκB Signaling, Institute of Molecular Biology (IMCB), A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore; Department of Pathology and the Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore.
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33
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Martínez‐García B, Dyson S, Segura J, Ayats A, Cutts EE, Gutierrez‐Escribano P, Aragón L, Roca J. Condensin pinches a short negatively supercoiled DNA loop during each round of ATP usage. EMBO J 2023; 42:e111913. [PMID: 36533296 PMCID: PMC9890231 DOI: 10.15252/embj.2022111913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 10/23/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Condensin, an SMC (structural maintenance of chromosomes) protein complex, extrudes DNA loops using an ATP-dependent mechanism that remains to be elucidated. Here, we show how condensin activity alters the topology of the interacting DNA. High condensin concentrations restrain positive DNA supercoils. However, in experimental conditions of DNA loop extrusion, condensin restrains negative supercoils. Namely, following ATP-mediated loading onto DNA, each condensin complex constrains a DNA linking number difference (∆Lk) of -0.4. This ∆Lk increases to -0.8 during ATP binding and resets to -0.4 upon ATP hydrolysis. These changes in DNA topology do not involve DNA unwinding, do not spread outside the condensin-DNA complex and can occur in the absence of the condensin subunit Ycg1. These findings indicate that during ATP binding, a short DNA domain delimited by condensin is pinched into a negatively supercoiled loop. We propose that this loop is the feeding segment of DNA that is subsequently merged to enlarge an extruding loop. Such a "pinch and merge" mechanism implies that two DNA-binding sites produce the feeding loop, while a third site, plausibly involving Ycg1, might anchor the extruding loop.
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Affiliation(s)
| | - Sílvia Dyson
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Joana Segura
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Alba Ayats
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Erin E Cutts
- DNA Motors GroupMRC London Institute of Medical Sciences (LMS)LondonUK
| | | | - Luís Aragón
- DNA Motors GroupMRC London Institute of Medical Sciences (LMS)LondonUK
| | - Joaquim Roca
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
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34
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Kabakci Z, Reichle HE, Lemke B, Rousova D, Gupta S, Weber J, Schleiffer A, Weir JR, Lehner CF. Homologous chromosomes are stably conjoined for Drosophila male meiosis I by SUM, a multimerized protein assembly with modules for DNA-binding and for separase-mediated dissociation co-opted from cohesin. PLoS Genet 2022; 18:e1010547. [DOI: 10.1371/journal.pgen.1010547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/20/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022] Open
Abstract
For meiosis I, homologous chromosomes must be paired into bivalents. Maintenance of homolog conjunction in bivalents until anaphase I depends on crossovers in canonical meiosis. However, instead of crossovers, an alternative system achieves homolog conjunction during the achiasmate male meiosis of Drosophila melanogaster. The proteins SNM, UNO and MNM are likely constituents of a physical linkage that conjoins homologs in D. melanogaster spermatocytes. Here, we report that SNM binds tightly to the C-terminal region of UNO. This interaction is homologous to that of the cohesin subunits stromalin/Scc3/STAG and α-kleisin, as revealed by sequence similarities, structure modeling and cross-link mass spectrometry. Importantly, purified SU_C, the heterodimeric complex of SNM and the C-terminal region of UNO, displayed DNA-binding in vitro. DNA-binding was severely impaired by mutational elimination of positively charged residues from the C-terminal helix of UNO. Phenotypic analyses in flies fully confirmed the physiological relevance of this basic helix for chromosome-binding and homolog conjunction during male meiosis. Beyond DNA, SU_C also bound MNM, one of many isoforms expressed from the complex mod(mdg4) locus. This binding of MNM to SU_C was mediated by the MNM-specific C-terminal region, while the purified N-terminal part common to all Mod(mdg4) isoforms multimerized into hexamers in vitro. Similarly, the UNO N-terminal domain formed tetramers in vitro. Thus, we suggest that multimerization confers to SUM, the assemblies composed of SNM, UNO and MNM, the capacity to conjoin homologous chromosomes stably by the resultant multivalent DNA-binding. Moreover, to permit homolog separation during anaphase I, SUM is dissociated by separase, since UNO, the α-kleisin-related protein, includes a separase cleavage site. In support of this proposal, we demonstrate that UNO cleavage by tobacco etch virus protease is sufficient to release homolog conjunction in vivo after mutational exchange of the separase cleavage site with that of the bio-orthogonal protease.
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35
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Freitag M, Jaklin S, Padovani F, Radzichevici E, Zernia S, Schmoller KM, Stigler J. Single-molecule experiments reveal the elbow as an essential folding guide in SMC coiled-coil arms. Biophys J 2022; 121:4702-4713. [PMID: 36242515 PMCID: PMC9748247 DOI: 10.1016/j.bpj.2022.10.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/16/2022] [Accepted: 10/12/2022] [Indexed: 11/19/2022] Open
Abstract
Structural maintenance of chromosome (SMC) complexes form ring-like structures through exceptional elongated coiled-coils (CCs). Recent studies found that variable CC conformations, including open and collapsed forms, which might result from discontinuities in the CC, facilitate the diverse functions of SMCs in DNA organization. However, a detailed description of the SMC CC architecture is still missing. Here, we study the structural composition and mechanical properties of SMC proteins with optical tweezers unfolding experiments using the isolated Psm3 CC as a model system. We find a comparatively unstable protein with three unzipping intermediates, which we could directly assign to CC features by crosslinking experiments and state-of-the-art prediction software. Particularly, the CC elbow is shown to be a flexible, potentially non-structured feature, which divides the CC into sections, induces a pairing shift from one CC strand to the other and could facilitate large-scale conformational changes, most likely via thermal fluctuations of the flanking CC sections. A replacement of the elbow amino acids hinders folding of the consecutive CC region and frequently leads to non-native misalignments, revealing the elbow as a guide for proper folding. Additional in vivo manipulation of the elbow flexibility resulted in impaired cohesin complexes, which directly link the sensitive CC architecture to the biological function of cohesin.
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Affiliation(s)
- Marvin Freitag
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sigrun Jaklin
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Francesco Padovani
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany
| | | | - Sarah Zernia
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Kurt M Schmoller
- Institute of Functional Epigenetics, Helmholtz Zentrum München, Neuherberg, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Johannes Stigler
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany.
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36
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Rossini R, Kumar V, Mathelier A, Rognes T, Paulsen J. MoDLE: high-performance stochastic modeling of DNA loop extrusion interactions. Genome Biol 2022; 23:247. [PMID: 36451166 PMCID: PMC9710047 DOI: 10.1186/s13059-022-02815-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
DNA loop extrusion emerges as a key process establishing genome structure and function. We introduce MoDLE, a computational tool for fast, stochastic modeling of molecular contacts from DNA loop extrusion capable of simulating realistic contact patterns genome wide in a few minutes. MoDLE accurately simulates contact maps in concordance with existing molecular dynamics approaches and with Micro-C data and does so orders of magnitude faster than existing approaches. MoDLE runs efficiently on machines ranging from laptops to high performance computing clusters and opens up for exploratory and predictive modeling of 3D genome structure in a wide range of settings.
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Affiliation(s)
- Roberto Rossini
- grid.5510.10000 0004 1936 8921Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Vipin Kumar
- grid.5510.10000 0004 1936 8921Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, 0318 Oslo, Norway
| | - Anthony Mathelier
- grid.5510.10000 0004 1936 8921Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, 0318 Oslo, Norway
| | - Torbjørn Rognes
- grid.5510.10000 0004 1936 8921Centre for Bioinformatics, Department of Informatics, University of Oslo, 0316 Oslo, Norway ,grid.55325.340000 0004 0389 8485Department of Microbiology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway
| | - Jonas Paulsen
- grid.5510.10000 0004 1936 8921Department of Biosciences, University of Oslo, 0316 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Bioinformatics, Department of Informatics, University of Oslo, 0316 Oslo, Norway
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Abstract
Cohesin, a structural maintenance of chromosome (SMC) complex, organizes chromatin into three-dimensional structures by threading chromatin into loops and stabilizing long-range chromatin interactions. Four subunits in a 1:1:1:1 ratio compose the cohesin core, which is regulated by auxiliary factors that interact with or modify the core subunits. An ongoing debate about cohesin's mechanism of action regards its stoichiometry. Namely, is cohesin activity mediated by a single complex or cooperation between several complexes that organize into dimers or oligomers? Several investigations that used various experimental approaches have tried to resolve this dispute. Some have convincingly demonstrated that the cohesin monomer is the active unit. However, others have revealed the formation of cohesin dimers and higher-order clusters on and off chromosomes. Elucidating the biological function of cohesin clusters and determining what regulates their formation are just two of the many new questions raised by these findings. We briefly review the history of the argument about cohesin stoichiometry and the central evidence for cohesin activity as a monomer vs. an oligomer. Finally, we discuss the possible biological significance of cohesin oligomerization and present open questions that remain to be answered.
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Affiliation(s)
| | - Itay Onn
- The Azrieli Faculty of Medicine, Bar-Ilan University, Ramat Gan, Safed, Israel
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38
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Fujita Y, Pather SR, Ming GL, Song H. 3D spatial genome organization in the nervous system: From development and plasticity to disease. Neuron 2022; 110:2902-2915. [PMID: 35777365 PMCID: PMC9509413 DOI: 10.1016/j.neuron.2022.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/15/2022] [Accepted: 06/03/2022] [Indexed: 01/03/2023]
Abstract
Chromatin is organized into multiscale three-dimensional structures, including chromosome territories, A/B compartments, topologically associating domains, and chromatin loops. This hierarchically organized genomic architecture regulates gene transcription, which, in turn, is essential for various biological processes during brain development and adult plasticity. Here, we review different aspects of spatial genome organization and their functions in regulating gene expression in the nervous system, as well as their dysregulation in brain disorders. We also highlight new technologies to probe and manipulate chromatin architecture and discuss how investigating spatial genome organization can lead to a better understanding of the nervous system and associated disorders.
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Affiliation(s)
- Yuki Fujita
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Developmental Biology, Faculty of Medicine, Shimane University, Izumo City, Shimane 693-8501, Japan.
| | - Sarshan R Pather
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Guo-Li Ming
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hongjun Song
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Abdul F, Diman A, Baechler B, Ramakrishnan D, Kornyeyev D, Beran RK, Fletcher SP, Strubin M. Smc5/6 silences episomal transcription by a three-step function. Nat Struct Mol Biol 2022. [PMID: 36097294 DOI: 10.1038/s41594-022-00829-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 07/29/2022] [Indexed: 11/08/2022]
Abstract
In addition to its role in chromosome maintenance, the six-membered Smc5/6 complex functions as a restriction factor that binds to and transcriptionally silences viral and other episomal DNA. However, the underlying mechanism is unknown. Here, we show that transcriptional silencing by the human Smc5/6 complex is a three-step process. The first step is entrapment of the episomal DNA by a mechanism dependent on Smc5/6 ATPase activity and a function of its Nse4a subunit for which the Nse4b paralog cannot substitute. The second step results in Smc5/6 recruitment to promyelocytic leukemia nuclear bodies by SLF2 (the human ortholog of Nse6). The third step promotes silencing through a mechanism requiring Nse2 but not its SUMO ligase activity. By contrast, the related cohesin and condensin complexes fail to bind to or silence episomal DNA, indicating a property unique to Smc5/6.
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40
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Arruda NL, Bryan AF, Dowen JM. PDS5A and PDS5B differentially affect gene expression without altering cohesin localization across the genome. Epigenetics Chromatin 2022; 15:30. [PMID: 35986423 PMCID: PMC9392266 DOI: 10.1186/s13072-022-00463-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/28/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Cohesin is an important structural regulator of the genome, regulating both three-dimensional genome organization and gene expression. The core cohesin trimer interacts with various HEAT repeat accessory subunits, yielding cohesin complexes of distinct compositions and potentially distinct functions. The roles of the two mutually exclusive HEAT repeat subunits PDS5A and PDS5B are not well understood. RESULTS Here, we determine that PDS5A and PDS5B have highly similar localization patterns across the mouse embryonic stem cell (mESC) genome and they show a strong overlap with other cohesin HEAT repeat accessory subunits, STAG1 and STAG2. Using CRISPR/Cas9 genome editing to generate individual stable knockout lines for PDS5A and PDS5B, we find that loss of one PDS5 subunit does not alter the distribution of the other PDS5 subunit, nor the core cohesin complex. Both PDS5A and PDS5B are required for proper gene expression, yet they display only partially overlapping effects on gene targets. Remarkably, gene expression following dual depletion of the PDS5 HEAT repeat proteins does not completely overlap the gene expression changes caused by dual depletion of the STAG HEAT repeat proteins, despite the overlapping genomic distribution of all four proteins. Furthermore, dual loss of PDS5A and PDS5B decreases cohesin association with NIPBL and WAPL, reduces SMC3 acetylation, and does not alter overall levels of cohesin on the genome. CONCLUSIONS This work reveals the importance of PDS5A and PDS5B for proper cohesin function. Loss of either subunit has little effect on cohesin localization across the genome yet PDS5A and PDS5B are differentially required for gene expression.
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Affiliation(s)
- Nicole L Arruda
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Audra F Bryan
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jill M Dowen
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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41
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Abstract
Meiosis increases genetic diversity in offspring by generating genetically unique haploid gametes with reshuffled chromosomes. This process requires a specialized set of meiotic proteins, which facilitate chromosome recombination and segregation. However, re-expression of meiotic proteins in mitosis can have catastrophic oncogenic consequences and aberrant expression of meiotic proteins is a common occurrence in human tumors. Mechanistically, re-activation of meiotic genes in cancer promotes oncogenesis likely because cancers-conversely to healthy mitosis-are fueled by genetic instability which promotes tumor evolution, and evasion of immune response and treatment pressure. In this review, we explore similarities between meiotic and cancer cells with a particular focus on the oncogenic activation of meiotic genes in cancer. We emphasize the role of histones and their modifications, DNA methylation, genome organization, R-loops and the availability of distal enhancers.
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42
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Yu Y, Li S, Ser Z, Kuang H, Than T, Guan D, Zhao X, Patel DJ. Cryo-EM structure of DNA-bound Smc5/6 reveals DNA clamping enabled by multi-subunit conformational changes. Proc Natl Acad Sci U S A 2022; 119:e2202799119. [PMID: 35648833 DOI: 10.1073/pnas.2202799119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Smc5/6 complex plays multiple roles in DNA replication and repair. Its genome-protecting functions rely on its interaction with DNA; however, how this complex engages DNA is poorly understood. We report on a cryogenic electron microscopy structure of DNA-bound budding yeast Smc5/6 complex, revealing that its subunits form a clamp to encircle a double-helical DNA. We define the multi-subunit interactions forming the DNA clamp and the DNA binding sites distributed among subunits. We identify subunit transformations upon DNA capture and functional effects conferred by its multiple DNA contact sites. Our findings, in conjunction with studies on other structural maintenance of chromosomes (SMC) complexes, suggest a common SMC DNA-clamp mechanism with individual complex specific features that enable diverse genome organization and protection functions by SMC family complexes. Structural maintenance of chromosomes (SMC) complexes are essential for chromatin organization and functions throughout the cell cycle. The cohesin and condensin SMCs fold and tether DNA, while Smc5/6 directly promotes DNA replication and repair. The functions of SMCs rely on their abilities to engage DNA, but how Smc5/6 binds and translocates on DNA remains largely unknown. Here, we present a 3.8 Å cryogenic electron microscopy (cryo-EM) structure of DNA-bound Saccharomyces cerevisiae Smc5/6 complex containing five of its core subunits, including Smc5, Smc6, and the Nse1-3-4 subcomplex. Intricate interactions among these subunits support the formation of a clamp that encircles the DNA double helix. The positively charged inner surface of the clamp contacts DNA in a nonsequence-specific manner involving numerous DNA binding residues from four subunits. The DNA duplex is held up by Smc5 and 6 head regions and positioned between their coiled-coil arm regions, reflecting an engaged-head and open-arm configuration. The Nse3 subunit secures the DNA from above, while the hook-shaped Nse4 kleisin forms a scaffold connecting DNA and all other subunits. The Smc5/6 DNA clamp shares similarities with DNA-clamps formed by other SMCs but also exhibits differences that reflect its unique functions. Mapping cross-linking mass spectrometry data derived from DNA-free Smc5/6 to the DNA-bound Smc5/6 structure identifies multi-subunit conformational changes that enable DNA capture. Finally, mutational data from cells reveal distinct DNA binding contributions from each subunit to Smc5/6 chromatin association and cell fitness. In summary, our integrative study illuminates how a unique SMC complex engages DNA in supporting genome regulation.
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43
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Shaltiel IA, Datta S, Lecomte L, Hassler M, Kschonsak M, Bravo S, Stober C, Ormanns J, Eustermann S, Haering CH. A hold-and-feed mechanism drives directional DNA loop extrusion by condensin. Science 2022; 376:1087-1094. [PMID: 35653469 DOI: 10.1126/science.abm4012] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Structural maintenance of chromosomes (SMC) protein complexes structure genomes by extruding DNA loops, but the molecular mechanism that underlies their activity has remained unknown. We show that the active condensin complex entraps the bases of a DNA loop transiently in two separate chambers. Single-molecule imaging and cryo-electron microscopy suggest a putative power-stroke movement at the first chamber that feeds DNA into the SMC-kleisin ring upon adenosine triphosphate binding, whereas the second chamber holds on upstream of the same DNA double helix. Unlocking the strict separation of "motor" and "anchor" chambers turns condensin from a one-sided into a bidirectional DNA loop extruder. We conclude that the orientation of two topologically bound DNA segments during the SMC reaction cycle determines the directionality of DNA loop extrusion.
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Affiliation(s)
- Indra A Shaltiel
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Sumanjit Datta
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Léa Lecomte
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Markus Hassler
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Marc Kschonsak
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Sol Bravo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Catherine Stober
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Jenny Ormanns
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany
| | | | - Christian H Haering
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Structural and Computational Biology Unit, EMBL, 69117 Heidelberg, Germany
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44
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van Ruiten MS, van Gent D, Sedeño Cacciatore Á, Fauster A, Willems L, Hekkelman ML, Hoekman L, Altelaar M, Haarhuis JHI, Brummelkamp TR, de Wit E, Rowland BD. The cohesin acetylation cycle controls chromatin loop length through a PDS5A brake mechanism. Nat Struct Mol Biol 2022; 29:586-591. [PMID: 35710836 PMCID: PMC9205776 DOI: 10.1038/s41594-022-00773-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 04/05/2022] [Indexed: 12/16/2022]
Abstract
Cohesin structures the genome through the formation of chromatin loops and by holding together the sister chromatids. The acetylation of cohesin's SMC3 subunit is a dynamic process that involves the acetyltransferase ESCO1 and deacetylase HDAC8. Here we show that this cohesin acetylation cycle controls the three-dimensional genome in human cells. ESCO1 restricts the length of chromatin loops, and of architectural stripes emanating from CTCF sites. HDAC8 conversely promotes the extension of such loops and stripes. This role in controlling loop length turns out to be distinct from the canonical role of cohesin acetylation that protects against WAPL-mediated DNA release. We reveal that acetylation controls the interaction of cohesin with PDS5A to restrict chromatin loop length. Our data support a model in which this PDS5A-bound state acts as a brake that enables the pausing and restart of loop enlargement. The cohesin acetylation cycle hereby provides punctuation in the process of genome folding.
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Affiliation(s)
- Marjon S van Ruiten
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Démi van Gent
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | | | - Astrid Fauster
- Division of Biochemistry, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Laureen Willems
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Maarten L Hekkelman
- Division of Biochemistry, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Liesbeth Hoekman
- Proteomics Facility, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Maarten Altelaar
- Proteomics Facility, The Netherlands Cancer Institute, Amsterdam, the Netherlands
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht Institute for Pharmaceutical Sciences, Utrecht University and Netherlands Proteomics Centre, Utrecht, the Netherlands
| | - Judith H I Haarhuis
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Thijn R Brummelkamp
- Division of Biochemistry, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Elzo de Wit
- Division of Gene Regulation, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Benjamin D Rowland
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, the Netherlands.
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45
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Dequeker BJH, Scherr MJ, Brandão HB, Gassler J, Powell S, Gaspar I, Flyamer IM, Lalic A, Tang W, Stocsits R, Davidson IF, Peters JM, Duderstadt KE, Mirny LA, Tachibana K. MCM complexes are barriers that restrict cohesin-mediated loop extrusion. Nature 2022; 606:197-203. [PMID: 35585235 PMCID: PMC9159944 DOI: 10.1038/s41586-022-04730-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 04/06/2022] [Indexed: 12/23/2022]
Abstract
Eukaryotic genomes are compacted into loops and topologically associating domains (TADs)1-3, which contribute to transcription, recombination and genomic stability4,5. Cohesin extrudes DNA into loops that are thought to lengthen until CTCF boundaries are encountered6-12. Little is known about whether loop extrusion is impeded by DNA-bound machines. Here we show that the minichromosome maintenance (MCM) complex is a barrier that restricts loop extrusion in G1 phase. Single-nucleus Hi-C (high-resolution chromosome conformation capture) of mouse zygotes reveals that MCM loading reduces CTCF-anchored loops and decreases TAD boundary insulation, which suggests that loop extrusion is impeded before reaching CTCF. This effect extends to HCT116 cells, in which MCMs affect the number of CTCF-anchored loops and gene expression. Simulations suggest that MCMs are abundant, randomly positioned and partially permeable barriers. Single-molecule imaging shows that MCMs are physical barriers that frequently constrain cohesin translocation in vitro. Notably, chimeric yeast MCMs that contain a cohesin-interaction motif from human MCM3 induce cohesin pausing, indicating that MCMs are 'active' barriers with binding sites. These findings raise the possibility that cohesin can arrive by loop extrusion at MCMs, which determine the genomic sites at which sister chromatid cohesion is established. On the basis of in vivo, in silico and in vitro data, we conclude that distinct loop extrusion barriers shape the three-dimensional genome.
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Affiliation(s)
- Bart J H Dequeker
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Matthias J Scherr
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry (MPIB), Martinsried, Germany
| | - Hugo B Brandão
- Harvard Program in Biophysics, Harvard University, Cambridge, MA, USA
- Illumina Inc., San Diego, CA, USA
| | - Johanna Gassler
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Department of Totipotency, Max Planck Institute of Biochemistry (MPIB), Martinsried, Germany
| | - Sean Powell
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Imre Gaspar
- Department of Totipotency, Max Planck Institute of Biochemistry (MPIB), Martinsried, Germany
| | - Ilya M Flyamer
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine (IGMM), University of Edinburgh, Edinburgh, UK
| | - Aleksandar Lalic
- Department of Totipotency, Max Planck Institute of Biochemistry (MPIB), Martinsried, Germany
| | - Wen Tang
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Roman Stocsits
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Iain F Davidson
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Karl E Duderstadt
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry (MPIB), Martinsried, Germany.
- Department of Physics, Technical University of Munich, Garching, Germany.
| | - Leonid A Mirny
- Department of Physics, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
| | - Kikuë Tachibana
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.
- Department of Totipotency, Max Planck Institute of Biochemistry (MPIB), Martinsried, Germany.
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46
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Asor R, Kukura P. Characterising biomolecular interactions and dynamics with mass photometry. Curr Opin Chem Biol 2022; 68:102132. [DOI: 10.1016/j.cbpa.2022.102132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/22/2022] [Indexed: 12/25/2022]
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47
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Panarotto M, Davidson IF, Litos G, Schleiffer A, Peters JM. Cornelia de Lange syndrome mutations in NIPBL can impair cohesin-mediated DNA loop extrusion. Proc Natl Acad Sci U S A 2022; 119:e2201029119. [PMID: 35476527 PMCID: PMC9170158 DOI: 10.1073/pnas.2201029119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 03/25/2022] [Indexed: 11/22/2022] Open
Abstract
Cornelia de Lange syndrome (CdLS) is a developmental multisystem disorder frequently associated with mutations in NIPBL. CdLS is thought to arise from developmental gene regulation defects, but how NIPBL mutations cause these is unknown. Here we show that several NIPBL mutations impair the DNA loop extrusion activity of cohesin. Because this activity is required for the formation of chromatin loops and topologically associating domains, which have important roles in gene regulation, our results suggest that defects in cohesin-mediated loop extrusion contribute to the etiology of CdLS by altering interactions between developmental genes and their enhancers.
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Affiliation(s)
- Melanie Panarotto
- Research Institute of Molecular Pathology, Vienna BioCenter, 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, A-1030 Vienna, Austria
| | - Iain F. Davidson
- Research Institute of Molecular Pathology, Vienna BioCenter, 1030 Vienna, Austria
| | - Gabriele Litos
- Research Institute of Molecular Pathology, Vienna BioCenter, 1030 Vienna, Austria
| | - Alexander Schleiffer
- Research Institute of Molecular Pathology, Vienna BioCenter, 1030 Vienna, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology, Vienna BioCenter, 1030 Vienna, Austria
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48
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Nomidis SK, Carlon E, Gruber S, Marko JF. DNA tension-modulated translocation and loop extrusion by SMC complexes revealed by molecular dynamics simulations. Nucleic Acids Res 2022; 50:4974-4987. [PMID: 35474142 PMCID: PMC9122525 DOI: 10.1093/nar/gkac268] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 03/21/2022] [Accepted: 04/04/2022] [Indexed: 12/19/2022] Open
Abstract
Structural Maintenance of Chromosomes (SMC) complexes play essential roles in genome organization across all domains of life. To determine how the activities of these large (≈50 nm) complexes are controlled by ATP binding and hydrolysis, we developed a molecular dynamics model that accounts for conformational motions of the SMC and DNA. The model combines DNA loop capture with an ATP-induced ‘power stroke’ to translocate the SMC complex along DNA. This process is sensitive to DNA tension: at low tension (0.1 pN), the model makes loop-capture steps of average 60 nm and up to 200 nm along DNA (larger than the complex itself), while at higher tension, a distinct inchworm-like translocation mode appears. By tethering DNA to an experimentally-observed additional binding site (‘safety belt’), the model SMC complex can perform loop extrusion (LE). The dependence of LE on DNA tension is distinct for fixed DNA tension vs. fixed DNA end points: LE reversal occurs above 0.5 pN for fixed tension, while LE stalling without reversal occurs at about 2 pN for fixed end points. Our model matches recent experimental results for condensin and cohesin, and makes testable predictions for how specific structural variations affect SMC function.
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Affiliation(s)
- Stefanos K Nomidis
- Laboratory for Soft Matter and Biophysics, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
- Flemish Institute for Technological Research (VITO), Boeretang 200, B-2400 Mol, Belgium
| | - Enrico Carlon
- Laboratory for Soft Matter and Biophysics, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - Stephan Gruber
- Départment de Microbiologie Fondamentale, Université de Lausanne, 1015 Lausanne, Switzerland
| | - John F Marko
- To whom correspondence should be addressed. Tel: +1 847 467 1276; Fax: +1 847 467 1380;
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49
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Oldenkamp R, Rowland BD. A walk through the SMC cycle: From catching DNAs to shaping the genome. Mol Cell 2022:S1097-2765(22)00317-3. [PMID: 35477004 DOI: 10.1016/j.molcel.2022.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 02/02/2022] [Accepted: 04/04/2022] [Indexed: 12/16/2022]
Abstract
SMC protein complexes are molecular machines that provide structure to chromosomes. These complexes bridge DNA elements and by doing so build DNA loops in cis and hold together the sister chromatids in trans. We discuss how drastic conformational changes allow SMC complexes to build such intricate DNA structures. The tight regulation of these complexes controls fundamental chromosomal processes such as transcription, recombination, repair, and mitosis.
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50
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Abstract
SignificanceDNA needs to be compacted to fit into nuclei and during cell division, when dense chromatids are formed for their mechanical segregation, a process that depends on the protein complex condensin. It forms and enlarges loops in DNA through loop extrusion. Our work resolves the atomic structure of a DNA-bound state of condensin in which ATP has not been hydrolyzed. The DNA is clamped within a compartment that has been reported previously in other structural maintenance of chromosomes (SMC) complexes, including Rad50, cohesin, and MukBEF. With the caveat of important differences, it means that all SMC complexes cycle through at least some similar states and undergo similar conformational changes in their head modules, while hydrolyzing ATP and translocating DNA.
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Affiliation(s)
- Byung-Gil Lee
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - James Rhodes
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Jan Löwe
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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