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Rahman F, Augoustides V, Tyler E, Daugird TA, Arthur C, Legant WR. Mapping the nuclear landscape with multiplexed super-resolution fluorescence microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.27.605159. [PMID: 39211261 PMCID: PMC11360932 DOI: 10.1101/2024.07.27.605159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The nucleus coordinates many different processes. Visualizing how these are spatially organized requires imaging protein complexes, epigenetic marks, and DNA across scales from single molecules to the whole nucleus. To accomplish this, we developed a multiplexed imaging protocol to localize 13 different nuclear targets with nanometer precision in single cells. We show that nuclear specification into active and repressive states exists along a spectrum of length scales, emerging below one micron and becoming strengthened at the nanoscale with unique organizational principles in both heterochromatin and euchromatin. HP1-α was positively correlated with DNA at the microscale but uncorrelated at the nanoscale. RNA Polymerase II, p300, and CDK9 were positively correlated at the microscale but became partitioned below 300 nm. Perturbing histone acetylation or transcription disrupted nanoscale organization but had less effect at the microscale. We envision that our imaging and analysis pipeline will be useful to reveal the organizational principles not only of the cell nucleus but also other cellular compartments.
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2
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Huber J, Tanasie NL, Zernia S, Stigler J. Single-molecule imaging reveals a direct role of CTCF's zinc fingers in SA interaction and cluster-dependent RNA recruitment. Nucleic Acids Res 2024; 52:6490-6506. [PMID: 38742641 PMCID: PMC11194110 DOI: 10.1093/nar/gkae391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/21/2024] [Accepted: 05/01/2024] [Indexed: 05/16/2024] Open
Abstract
CTCF is a zinc finger protein associated with transcription regulation that also acts as a barrier factor for topologically associated domains (TADs) generated by cohesin via loop extrusion. These processes require different properties of CTCF-DNA interaction, and it is still unclear how CTCF's structural features may modulate its diverse roles. Here, we employ single-molecule imaging to study both full-length CTCF and truncation mutants. We show that CTCF enriches at CTCF binding sites (CBSs), displaying a longer lifetime than observed previously. We demonstrate that the zinc finger domains mediate CTCF clustering and that clustering enables RNA recruitment, possibly creating a scaffold for interaction with RNA-binding proteins like cohesin's subunit SA. We further reveal a direct recruitment and an increase of SA residence time by CTCF bound at CBSs, suggesting that CTCF-SA interactions are crucial for cohesin stability on chromatin at TAD borders. Furthermore, we establish a single-molecule T7 transcription assay and show that although a transcribing polymerase can remove CTCF from CBSs, transcription is impaired. Our study shows that context-dependent nucleic acid binding determines the multifaceted CTCF roles in genome organization and transcription regulation.
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Affiliation(s)
- Jonas Huber
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | | | - Sarah Zernia
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Johannes Stigler
- Gene Center Munich, Ludwig-Maximilians-Universität München, Munich, Germany
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3
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Wagner T, Priyanka P, Micheletti R, Friedman MJ, Nair SJ, Gamliel A, Taylor H, Song X, Cho M, Oh S, Li W, Han J, Ohgi KA, Abrass M, D'Antonio-Chronowska A, D'Antonio M, Hazuda H, Duggirala R, Blangero J, Ding S, Guzmann C, Frazer KA, Aggarwal AK, Zemljic-Harpf AE, Rosenfeld MG, Suh Y. Recruitment of CTCF to the SIRT1 promoter after Oxidative Stress mediates Cardioprotective Transcription. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594600. [PMID: 38798402 PMCID: PMC11118446 DOI: 10.1101/2024.05.17.594600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Because most DNA-binding transcription factors (dbTFs), including the architectural regulator CTCF, bind RNA and exhibit di-/multimerization, a central conundrum is whether these distinct properties are regulated post-transcriptionally to modulate transcriptional programs. Here, investigating stress-dependent activation of SIRT1, encoding an evolutionarily-conserved protein deacetylase, we show that induced phosphorylation of CTCF acts as a rheostat to permit CTCF occupancy of low-affinity promoter DNA sites to precisely the levels necessary. This CTCF recruitment to the SIRT1 promoter is eliciting a cardioprotective cardiomyocyte transcriptional activation program and provides resilience against the stress of the beating heart in vivo . Mice harboring a mutation in the conserved low-affinity CTCF promoter binding site exhibit an altered, cardiomyocyte-specific transcriptional program and a systolic heart failure phenotype. This transcriptional role for CTCF reveals that a covalent dbTF modification regulating signal-dependent transcription serves as a previously unsuspected component of the oxidative stress response.
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Camerino M, Chang W, Cvekl A. Analysis of long-range chromatin contacts, compartments and looping between mouse embryonic stem cells, lens epithelium and lens fibers. Epigenetics Chromatin 2024; 17:10. [PMID: 38643244 PMCID: PMC11031936 DOI: 10.1186/s13072-024-00533-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/08/2024] [Indexed: 04/22/2024] Open
Abstract
BACKGROUND Nuclear organization of interphase chromosomes involves individual chromosome territories, "open" and "closed" chromatin compartments, topologically associated domains (TADs) and chromatin loops. The DNA- and RNA-binding transcription factor CTCF together with the cohesin complex serve as major organizers of chromatin architecture. Cellular differentiation is driven by temporally and spatially coordinated gene expression that requires chromatin changes of individual loci of various complexities. Lens differentiation represents an advantageous system to probe transcriptional mechanisms underlying tissue-specific gene expression including high transcriptional outputs of individual crystallin genes until the mature lens fiber cells degrade their nuclei. RESULTS Chromatin organization between mouse embryonic stem (ES) cells, newborn (P0.5) lens epithelium and fiber cells were analyzed using Hi-C. Localization of CTCF in both lens chromatins was determined by ChIP-seq and compared with ES cells. Quantitative analyses show major differences between number and size of TADs and chromatin loop size between these three cell types. In depth analyses show similarities between lens samples exemplified by overlaps between compartments A and B. Lens epithelium-specific CTCF peaks are found in mostly methylated genomic regions while lens fiber-specific and shared peaks occur mostly within unmethylated DNA regions. Major differences in TADs and loops are illustrated at the ~ 500 kb Pax6 locus, encoding the critical lens regulatory transcription factor and within a larger ~ 15 Mb WAGR locus, containing Pax6 and other loci linked to human congenital diseases. Lens and ES cell Hi-C data (TADs and loops) together with ATAC-seq, CTCF, H3K27ac, H3K27me3 and ENCODE cis-regulatory sites are shown in detail for the Pax6, Sox1 and Hif1a loci, multiple crystallin genes and other important loci required for lens morphogenesis. The majority of crystallin loci are marked by unexpectedly high CTCF-binding across their transcribed regions. CONCLUSIONS Our study has generated the first data on 3-dimensional (3D) nuclear organization in lens epithelium and lens fibers and directly compared these data with ES cells. These findings generate novel insights into lens-specific transcriptional gene control, open new research avenues to study transcriptional condensates in lens fiber cells, and enable studies of non-coding genetic variants linked to cataract and other lens and ocular abnormalities.
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Affiliation(s)
- Michael Camerino
- The Departments Genetics, Albert Einstein College of Medicine, NY10461, Bronx, USA
| | - William Chang
- Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, NY10461, Bronx, USA
| | - Ales Cvekl
- The Departments Genetics, Albert Einstein College of Medicine, NY10461, Bronx, USA.
- Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, NY10461, Bronx, USA.
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5
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Breton V, Nazac P, Boulet D, Danglot L. Molecular mapping of neuronal architecture using STORM microscopy and new fluorescent probes for SMLM imaging. NEUROPHOTONICS 2024; 11:014414. [PMID: 38464866 PMCID: PMC10923464 DOI: 10.1117/1.nph.11.1.014414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/27/2024] [Accepted: 01/31/2024] [Indexed: 03/12/2024]
Abstract
Imaging neuronal architecture has been a recurrent challenge over the years, and the localization of synaptic proteins is a frequent challenge in neuroscience. To quantitatively detect and analyze the structure of synapses, we recently developed free SODA software to detect the association of pre and postsynaptic proteins. To fully take advantage of spatial distribution analysis in complex cells, such as neurons, we also selected some new dyes for plasma membrane labeling. Using Icy SODA plugin, we could detect and analyze synaptic association in both conventional and single molecule localization microscopy, giving access to a molecular map at the nanoscale level. To replace those molecular distributions within the neuronal three-dimensional (3D) shape, we used MemBright probes and 3D STORM analysis to decipher the entire 3D shape of various dendritic spine types at the single-molecule resolution level. We report here the example of synaptic proteins within neuronal mask, but these tools have a broader spectrum of interest since they can be used whatever the proteins or the cellular type. Altogether with SODA plugin, MemBright probes thus provide the perfect toolkit to decipher a nanometric molecular map of proteins within a 3D cellular context.
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Affiliation(s)
- Victor Breton
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy and Diseased Brain, Paris, France
| | - Paul Nazac
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy and Diseased Brain, Paris, France
| | - David Boulet
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy and Diseased Brain, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, NeurImag Core Facility, Paris, France
| | - Lydia Danglot
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Membrane Traffic in Healthy and Diseased Brain, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, NeurImag Core Facility, Paris, France
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6
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Wang C, Zhao B. Epstein-Barr virus and host cell 3D genome organization. J Med Virol 2023; 95:e29234. [PMID: 37988227 PMCID: PMC10664867 DOI: 10.1002/jmv.29234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/23/2023]
Abstract
The human genome is organized in an extremely complexed yet ordered way within the nucleus. Genome organization plays a critical role in the regulation of gene expression. Viruses manipulate the host machinery to influence host genome organization to favor their survival and promote disease development. Epstein-Barr virus (EBV) is a common human virus, whose infection is associated with various diseases, including infectious mononucleosis, cancer, and autoimmune disorders. This review summarizes our current knowledge of how EBV uses different strategies to control the cellular 3D genome organization to affect cell gene expression to transform normal cells into lymphoblasts.
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Affiliation(s)
- Chong Wang
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Bo Zhao
- Department of Medicine, Division of Infectious Disease, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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7
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Idoko-Akoh A, Goldhill DH, Sheppard CM, Bialy D, Quantrill JL, Sukhova K, Brown JC, Richardson S, Campbell C, Taylor L, Sherman A, Nazki S, Long JS, Skinner MA, Shelton H, Sang HM, Barclay WS, McGrew MJ. Creating resistance to avian influenza infection through genome editing of the ANP32 gene family. Nat Commun 2023; 14:6136. [PMID: 37816720 PMCID: PMC10564915 DOI: 10.1038/s41467-023-41476-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/05/2023] [Indexed: 10/12/2023] Open
Abstract
Chickens genetically resistant to avian influenza could prevent future outbreaks. In chickens, influenza A virus (IAV) relies on host protein ANP32A. Here we use CRISPR/Cas9 to generate homozygous gene edited (GE) chickens containing two ANP32A amino acid substitutions that prevent viral polymerase interaction. After IAV challenge, 9/10 edited chickens remain uninfected. Challenge with a higher dose, however, led to breakthrough infections. Breakthrough IAV virus contained IAV polymerase gene mutations that conferred adaptation to the edited chicken ANP32A. Unexpectedly, this virus also replicated in chicken embryos edited to remove the entire ANP32A gene and instead co-opted alternative ANP32 protein family members, chicken ANP32B and ANP32E. Additional genome editing for removal of ANP32B and ANP32E eliminated all viral growth in chicken cells. Our data illustrate a first proof of concept step to generate IAV-resistant chickens and show that multiple genetic modifications will be required to curtail viral escape.
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Affiliation(s)
- Alewo Idoko-Akoh
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK.
| | - Daniel H Goldhill
- Department of Infectious Disease, Imperial College London, London, UK
- Royal Veterinary College, London, UK
| | - Carol M Sheppard
- Department of Infectious Disease, Imperial College London, London, UK
| | | | | | - Ksenia Sukhova
- Department of Infectious Disease, Imperial College London, London, UK
| | - Jonathan C Brown
- Department of Infectious Disease, Imperial College London, London, UK
| | | | - Ciara Campbell
- Department of Infectious Disease, Imperial College London, London, UK
| | - Lorna Taylor
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK
| | - Adrian Sherman
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK
| | | | - Jason S Long
- Department of Infectious Disease, Imperial College London, London, UK
- Division of Virology, National Institute for Biological Standards and Control, Potters Bar, UK
| | - Michael A Skinner
- Department of Infectious Disease, Imperial College London, London, UK
| | | | - Helen M Sang
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK.
| | - Wendy S Barclay
- Department of Infectious Disease, Imperial College London, London, UK.
| | - Mike J McGrew
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, UK.
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8
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Zhang H, Shi Z, Banigan EJ, Kim Y, Yu H, Bai XC, Finkelstein IJ. CTCF and R-loops are boundaries of cohesin-mediated DNA looping. Mol Cell 2023; 83:2856-2871.e8. [PMID: 37536339 DOI: 10.1016/j.molcel.2023.07.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 05/10/2023] [Accepted: 07/06/2023] [Indexed: 08/05/2023]
Abstract
Cohesin and CCCTC-binding factor (CTCF) are key regulatory proteins of three-dimensional (3D) genome organization. Cohesin extrudes DNA loops that are anchored by CTCF in a polar orientation. Here, we present direct evidence that CTCF binding polarity controls cohesin-mediated DNA looping. Using single-molecule imaging, we demonstrate that a critical N-terminal motif of CTCF blocks cohesin translocation and DNA looping. The cryo-EM structure of the cohesin-CTCF complex reveals that this CTCF motif ahead of zinc fingers can only reach its binding site on the STAG1 cohesin subunit when the N terminus of CTCF faces cohesin. Remarkably, a C-terminally oriented CTCF accelerates DNA compaction by cohesin. DNA-bound Cas9 and Cas12a ribonucleoproteins are also polar cohesin barriers, indicating that stalling may be intrinsic to cohesin itself. Finally, we show that RNA-DNA hybrids (R-loops) block cohesin-mediated DNA compaction in vitro and are enriched with cohesin subunits in vivo, likely forming TAD boundaries.
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Affiliation(s)
- Hongshan Zhang
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Zhubing Shi
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, Zhejiang, China; School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang, China; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Edward J Banigan
- Department of Physics, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yoori Kim
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Republic of Korea
| | - Hongtao Yu
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, Zhejiang, China; School of Life Sciences, Westlake University, Hangzhou 310024, Zhejiang, China; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Xiao-Chen Bai
- Department of Biophysics, Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Ilya J Finkelstein
- Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
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9
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Bond ML, Davis ES, Quiroga IY, Dey A, Kiran M, Love MI, Won H, Phanstiel DH. Chromatin loop dynamics during cellular differentiation are associated with changes to both anchor and internal regulatory features. Genome Res 2023; 33:1258-1268. [PMID: 37699658 PMCID: PMC10547260 DOI: 10.1101/gr.277397.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 07/07/2023] [Indexed: 09/14/2023]
Abstract
Three-dimensional (3D) chromatin structure has been shown to play a role in regulating gene transcription during biological transitions. Although our understanding of loop formation and maintenance is rapidly improving, much less is known about the mechanisms driving changes in looping and the impact of differential looping on gene transcription. One limitation has been a lack of well-powered differential looping data sets. To address this, we conducted a deeply sequenced Hi-C time course of megakaryocyte development comprising four biological replicates and 6 billion reads per time point. Statistical analysis revealed 1503 differential loops. Gained loop anchors were enriched for AP-1 occupancy and were characterized by large increases in histone H3K27ac (over 11-fold) but relatively small increases in CTCF and RAD21 binding (1.26- and 1.23-fold, respectively). Linear modeling revealed that changes in histone H3K27ac, chromatin accessibility, and JUN binding were better correlated with changes in looping than RAD21 and almost as well correlated as CTCF. Changes to epigenetic features between-rather than at-boundaries were highly predictive of changes in looping. Together these data suggest that although CTCF and RAD21 may be the core machinery dictating where loops form, other features (both at the anchors and within the loop boundaries) may play a larger role than previously anticipated in determining the relative loop strength across cell types and conditions.
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Affiliation(s)
- Marielle L Bond
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Eric S Davis
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Ivana Y Quiroga
- Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Anubha Dey
- Department of Systems and Computational Biology, University of Hyderabad, Hyderabad 500046, Telangana, India
| | - Manjari Kiran
- Department of Systems and Computational Biology, University of Hyderabad, Hyderabad 500046, Telangana, India
| | - Michael I Love
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Hyejung Won
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, USA;
- Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Douglas H Phanstiel
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA;
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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10
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Sun Y, Xu X, Zhao W, Zhang Y, Chen K, Li Y, Wang X, Zhang M, Xue B, Yu W, Hou Y, Wang C, Xie W, Li C, Kong D, Wang S, Sun Y. RAD21 is the core subunit of the cohesin complex involved in directing genome organization. Genome Biol 2023; 24:155. [PMID: 37381036 DOI: 10.1186/s13059-023-02982-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/07/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND The ring-shaped cohesin complex is an important factor for the formation of chromatin loops and topologically associating domains (TADs) by loop extrusion. However, the regulation of association between cohesin and chromatin is poorly understood. In this study, we use super-resolution imaging to reveal the unique role of cohesin subunit RAD21 in cohesin loading and chromatin structure regulation. RESULTS We directly visualize that up-regulation of RAD21 leads to excessive chromatin loop extrusion into a vermicelli-like morphology with RAD21 clustered into foci and excessively loaded cohesin bow-tying a TAD to form a beads-on-a-string-type pattern. In contrast, up-regulation of the other four cohesin subunits results in even distributions. Mechanistically, we identify that the essential role of RAD21 is attributed to the RAD21-loader interaction, which facilitates the cohesin loading process rather than increasing the abundance of cohesin complex upon up-regulation of RAD21. Furthermore, Hi-C and genomic analysis reveal how RAD21 up-regulation affects genome-wide higher-order chromatin structure. Accumulated contacts are shown at TAD corners while inter-TAD interactions increase after vermicelli formation. Importantly, we find that in breast cancer cells, the expression of RAD21 is aberrantly high with poor patient survival and RAD21 forms beads in the nucleus. Up-regulated RAD21 in HeLa cells leads to compartment switching and up-regulation of cancer-related genes. CONCLUSIONS Our results provide key insights into the molecular mechanism by which RAD21 facilitates the cohesin loading process and provide an explanation to how cohesin and loader work cooperatively to promote chromatin extrusion, which has important implications in construction of three-dimensional genome organization.
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Affiliation(s)
- Yuao Sun
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Xin Xu
- Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Wenxue Zhao
- Center for Bioinformatics, School of Life Sciences, Center for Statistical Science, Peking University, Beijing, 100871, China
| | - Yu Zhang
- Center for Stem Cell Biology and Regenerative Medicine, MOE Key Laboratory of Bioinformatics, School of Life Sciences, THU-PKU Center for Life Science, Tsinghua University, Beijing, 100084, China
| | - Keyang Chen
- Yuanpei College, Peking University, Beijing, 100871, China
| | - Yongzheng Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Xiaotian Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Mengling Zhang
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Boxin Xue
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
- College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Wanting Yu
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China
| | - Yingping Hou
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Chaobin Wang
- Breast Center, Peking University People's Hospital, Beijing, 100044, China
| | - Wei Xie
- Center for Stem Cell Biology and Regenerative Medicine, MOE Key Laboratory of Bioinformatics, School of Life Sciences, THU-PKU Center for Life Science, Tsinghua University, Beijing, 100084, China
| | - Cheng Li
- Center for Bioinformatics, School of Life Sciences, Center for Statistical Science, Peking University, Beijing, 100871, China
| | - Daochun Kong
- Peking-Tsinghua Center for Life Sciences, The National Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Shu Wang
- Breast Center, Peking University People's Hospital, Beijing, 100044, China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, School of Life Sciences, and Biomedical Pioneering Innovation Center (BIOPIC), Peking University, Beijing, 100871, China.
- Breast Center, Peking University People's Hospital, Beijing, 100044, China.
- National Biomedical Imaging Center, College of Future Technology, Peking University, Beijing, 100871, China.
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11
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Spencley AL, Bar S, Swigut T, Flynn RA, Lee CH, Chen LF, Bassik MC, Wysocka J. Co-transcriptional genome surveillance by HUSH is coupled to termination machinery. Mol Cell 2023; 83:1623-1639.e8. [PMID: 37164018 PMCID: PMC10915761 DOI: 10.1016/j.molcel.2023.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 01/12/2023] [Accepted: 04/12/2023] [Indexed: 05/12/2023]
Abstract
The HUSH complex recognizes and silences foreign DNA such as viruses, transposons, and transgenes without prior exposure to its targets. Here, we show that endogenous targets of the HUSH complex fall into two distinct classes based on the presence or absence of H3K9me3. These classes are further distinguished by their transposon content and differential response to the loss of HUSH. A de novo genomic rearrangement at the Sox2 locus induces a switch from H3K9me3-independent to H3K9me3-associated HUSH targeting, resulting in silencing. We further demonstrate that HUSH interacts with the termination factor WDR82 and-via its component MPP8-with nascent RNA. HUSH accumulates at sites of high RNAPII occupancy including long exons and transcription termination sites in a manner dependent on WDR82 and CPSF. Together, our results uncover the functional diversity of HUSH targets and show that this vertebrate-specific complex exploits evolutionarily ancient transcription termination machinery for co-transcriptional chromatin targeting and genome surveillance.
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Affiliation(s)
- Andrew L Spencley
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA; Cancer Biology Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Shiran Bar
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Tomek Swigut
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Ryan A Flynn
- Stem Cell Program, Boston Children's Hospital, Boston, MA, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | - Cameron H Lee
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Liang-Fu Chen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Michael C Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Joanna Wysocka
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA; Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA; Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.
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12
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Comerci CJ, McCarthy DG, Nosrati M, Kim KB, Kashani-Sabet M, Moerner WE, Leong SP. Nanometer-scale distribution of PD-1 in the melanoma tumor microenvironment. JOURNAL OF RADIOLOGY AND ONCOLOGY 2023; 7:20-25. [PMID: 37539093 PMCID: PMC10399701 DOI: 10.29328/journal.jro.1001048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
The nanometer-scale spatial organization of immune receptors plays a role in cell activation and suppression. While the connection between this spatial organization and cell signaling events is emerging from cell culture experiments, how these results translate to more physiologically relevant settings like the tumor microenvironment remains poorly understood due to the challenges of high-resolution imaging in vivo. Here we perform super-resolution immunofluorescence microscopy of human melanoma tissue sections to examine the spatial organization of the immune checkpoint inhibitor programmed cell death 1 (PD-1). We show that PD-1 exhibits a variety of organizations ranging from nanometer-scale clusters to more uniform membrane labeling. Our results demonstrate the capability of super-resolution imaging to examine the spatial organization of immune checkpoint markers in the tumor microenvironment, suggesting a future direction for both clinical and immunology research.
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Affiliation(s)
- Colin J Comerci
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
- Biophysics Program, Stanford University, Stanford, CA, 94305, USA
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Dannielle G McCarthy
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
- Chan-Zuckerberg Initiative, 801 Jefferson Ave, Redwood City, CA, 94063, USA
| | - Mehdi Nosrati
- Center for Melanoma Research and Treatment, California Pacific Medical Center, Research Institute, San Francisco, CA, 94107, USA
| | - Kevin B Kim
- Center for Melanoma Research and Treatment, California Pacific Medical Center, Research Institute, San Francisco, CA, 94107, USA
| | - Mohammed Kashani-Sabet
- Center for Melanoma Research and Treatment, California Pacific Medical Center, Research Institute, San Francisco, CA, 94107, USA
| | - WE Moerner
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Stanley P Leong
- Center for Melanoma Research and Treatment, California Pacific Medical Center, Research Institute, San Francisco, CA, 94107, USA
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13
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Burgers TCQ, Vlijm R. Fluorescence-based super-resolution-microscopy strategies for chromatin studies. Chromosoma 2023:10.1007/s00412-023-00792-9. [PMID: 37000292 PMCID: PMC10356683 DOI: 10.1007/s00412-023-00792-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/28/2023] [Accepted: 03/16/2023] [Indexed: 04/01/2023]
Abstract
Super-resolution microscopy (SRM) is a prime tool to study chromatin organisation at near biomolecular resolution in the native cellular environment. With fluorescent labels DNA, chromatin-associated proteins and specific epigenetic states can be identified with high molecular specificity. The aim of this review is to introduce the field of diffraction-unlimited SRM to enable an informed selection of the most suitable SRM method for a specific chromatin-related research question. We will explain both diffraction-unlimited approaches (coordinate-targeted and stochastic-localisation-based) and list their characteristic spatio-temporal resolutions, live-cell compatibility, image-processing, and ability for multi-colour imaging. As the increase in resolution, compared to, e.g. confocal microscopy, leads to a central role of the sample quality, important considerations for sample preparation and concrete examples of labelling strategies applicable to chromatin research are discussed. To illustrate how SRM-based methods can significantly improve our understanding of chromatin functioning, and to serve as an inspiring starting point for future work, we conclude with examples of recent applications of SRM in chromatin research.
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Affiliation(s)
- Thomas C Q Burgers
- Molecular Biophysics, Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Groningen, the Netherlands
| | - Rifka Vlijm
- Molecular Biophysics, Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Groningen, the Netherlands.
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14
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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] [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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15
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Banigan EJ, Tang W, van den Berg AA, Stocsits RR, Wutz G, Brandão HB, Busslinger GA, Peters JM, Mirny LA. Transcription shapes 3D chromatin organization by interacting with loop extrusion. Proc Natl Acad Sci U S A 2023; 120:e2210480120. [PMID: 36897969 PMCID: PMC10089175 DOI: 10.1073/pnas.2210480120] [Citation(s) in RCA: 52] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 12/03/2022] [Indexed: 03/12/2023] Open
Abstract
Cohesin folds mammalian interphase chromosomes by extruding the chromatin fiber into numerous loops. "Loop extrusion" can be impeded by chromatin-bound factors, such as CTCF, which generates characteristic and functional chromatin organization patterns. It has been proposed that transcription relocalizes or interferes with cohesin and that active promoters are cohesin loading sites. However, the effects of transcription on cohesin have not been reconciled with observations of active extrusion by cohesin. To determine how transcription modulates extrusion, we studied mouse cells in which we could alter cohesin abundance, dynamics, and localization by genetic "knockouts" of the cohesin regulators CTCF and Wapl. Through Hi-C experiments, we discovered intricate, cohesin-dependent contact patterns near active genes. Chromatin organization around active genes exhibited hallmarks of interactions between transcribing RNA polymerases (RNAPs) and extruding cohesins. These observations could be reproduced by polymer simulations in which RNAPs were moving barriers to extrusion that obstructed, slowed, and pushed cohesins. The simulations predicted that preferential loading of cohesin at promoters is inconsistent with our experimental data. Additional ChIP-seq experiments showed that the putative cohesin loader Nipbl is not predominantly enriched at promoters. Therefore, we propose that cohesin is not preferentially loaded at promoters and that the barrier function of RNAP accounts for cohesin accumulation at active promoters. Altogether, we find that RNAP is an extrusion barrier that is not stationary, but rather, translocates and relocalizes cohesin. Loop extrusion and transcription might interact to dynamically generate and maintain gene interactions with regulatory elements and shape functional genomic organization.
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Affiliation(s)
- Edward J. Banigan
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Wen Tang
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Aafke A. van den Berg
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Roman R. Stocsits
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Gordana Wutz
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Hugo B. Brandão
- Graduate Program in Biophysics, Harvard University, Cambridge, MA02138
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA02139
- The Broad Institute of MIT and Harvard, Cambridge, MA02142
| | - Georg A. Busslinger
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
- Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna1090, Austria
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna1090, Austria
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology, Vienna BioCenter1030Vienna, Austria
| | - Leonid A. Mirny
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA02139
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16
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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] [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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17
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de Wit E, Nora EP. New insights into genome folding by loop extrusion from inducible degron technologies. Nat Rev Genet 2023; 24:73-85. [PMID: 36180596 DOI: 10.1038/s41576-022-00530-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2022] [Indexed: 01/24/2023]
Abstract
Chromatin folds into dynamic loops that often span hundreds of kilobases and physically wire distant loci together for gene regulation. These loops are continuously created, extended and positioned by structural maintenance of chromosomes (SMC) protein complexes, such as condensin and cohesin, and their regulators, including CTCF, in a highly dynamic process known as loop extrusion. Genetic loss of extrusion factors is lethal, complicating their study. Inducible protein degradation technologies enable the depletion of loop extrusion factors within hours, leading to the rapid reconfiguration of chromatin folding. Here, we review how these technologies have changed our understanding of genome organization, upsetting long-held beliefs on its role in transcription. Finally, we examine recent models that attempt to reconcile observations after chronic versus acute perturbations, and discuss future developments in this rapidly developing field of research.
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Affiliation(s)
- Elzo de Wit
- Division of Gene Regulation, Oncode Institute, Amsterdam, the Netherlands.
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, the Netherlands.
| | - Elphège P Nora
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA.
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
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18
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Reed KSM, Davis ES, Bond ML, Cabrera A, Thulson E, Quiroga IY, Cassel S, Woolery KT, Hilton I, Won H, Love MI, Phanstiel DH. Temporal analysis suggests a reciprocal relationship between 3D chromatin structure and transcription. Cell Rep 2022; 41:111567. [PMID: 36323252 PMCID: PMC9707392 DOI: 10.1016/j.celrep.2022.111567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/19/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022] Open
Abstract
To infer potential causal relationships between 3D chromatin structure, enhancers, and gene transcription, we mapped each feature in a genome-wide fashion across eight narrowly spaced time points of macrophage activation. Enhancers and genes connected by loops exhibit stronger correlations between histone H3K27 acetylation and expression than can be explained by genomic distance or physical proximity alone. At these looped enhancer-promoter pairs, changes in acetylation at distal enhancers precede changes in gene expression. Changes in gene expression exhibit a directional bias at differential loop anchors; gained loops are associated with increased expression of genes oriented away from the center of the loop, and lost loops are often accompanied by high levels of transcription within the loop boundaries themselves. These results are consistent with a reciprocal relationship where loops can facilitate increased transcription by connecting promoters to distal enhancers, whereas high levels of transcription can impede loop formation.
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Affiliation(s)
- Kathleen S M Reed
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Eric S Davis
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Marielle L Bond
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Alan Cabrera
- Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Eliza Thulson
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Ivana Yoseli Quiroga
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Shannon Cassel
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kamisha T Woolery
- Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Isaac Hilton
- Department of Bioengineering, Rice University, Houston, TX 77005, USA; Department of Biosciences, Rice University, Houston, TX 77005, USA
| | - Hyejung Won
- Department of Genetics and Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Michael I Love
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biostatistics, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599, USA
| | - Douglas H Phanstiel
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA; Curriculum in Bioinformatics and Computational Biology, University of North Carolina, Chapel Hill, NC 27599, USA; Thurston Arthritis Research Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA.
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19
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Matityahu A, Onn I. It's all in the numbers: Cohesin stoichiometry. Front Mol Biosci 2022; 9:1010894. [PMID: 36330215 PMCID: PMC9623059 DOI: 10.3389/fmolb.2022.1010894] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/05/2022] [Indexed: 01/09/2024] Open
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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20
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Wang H, Li B, Zuo L, Wang B, Yan Y, Tian K, Zhou R, Wang C, Chen X, Jiang Y, Zheng H, Qin F, Zhang B, Yu Y, Liu CP, Xu Y, Gao J, Qi Z, Deng W, Ji X. The transcriptional coactivator RUVBL2 regulates Pol II clustering with diverse transcription factors. Nat Commun 2022; 13:5703. [PMID: 36171202 PMCID: PMC9519968 DOI: 10.1038/s41467-022-33433-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 09/16/2022] [Indexed: 11/10/2022] Open
Abstract
RNA polymerase II (Pol II) apparatuses are compartmentalized into transcriptional clusters. Whether protein factors control these clusters remains unknown. In this study, we find that the ATPase-associated with diverse cellular activities (AAA + ) ATPase RUVBL2 co-occupies promoters with Pol II and various transcription factors. RUVBL2 interacts with unphosphorylated Pol II in chromatin to promote RPB1 carboxy-terminal domain (CTD) clustering and transcription initiation. Rapid depletion of RUVBL2 leads to a decrease in the number of Pol II clusters and inhibits nascent RNA synthesis, and tethering RUVBL2 to an active promoter enhances Pol II clustering at the promoter. We also identify target genes that are directly linked to the RUVBL2-Pol II axis. Many of these genes are hallmarks of cancers and encode proteins with diverse cellular functions. Our results demonstrate an emerging activity for RUVBL2 in regulating Pol II cluster formation in the nucleus.
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Affiliation(s)
- Hui Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- Department of Pathogenic Biology, Chengdu Medical College, Chengdu, 610500, China
| | - Boyuan Li
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Linyu Zuo
- Center for Quantitative Biology, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Bo Wang
- Biomedical Pioneering Innovation Center (BIOPIC), Academy for Advanced Interdisciplinary Studies, Beijing Advanced Innovation Center for Genomics (ICG), Peking-Tsinghua Center for Life Sciences (CLS), School of Life Sciences, Peking University, Beijing, 100871, China
| | - Yan Yan
- Institute for TCM-X; MOE Key Laboratory of Bioinformatics; Bioinformatics Division, BNRist (Beijing National Research Center for Information Science and Technology); Department of Automation, Tsinghua University, Beijing, 100084, China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China
| | - Kai Tian
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Rong Zhou
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Chenlu Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Xizi Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Yongpeng Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Haonan Zheng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Fangfei Qin
- Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Bin Zhang
- Departments of Pathology and Laboratory Medicine, and Pediatrics, University of Rochester Medical Center, 601 Elmwood Ave, Box 608, Rochester, NY, 14642, USA
| | - Yang Yu
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chao-Pei Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, 200032, China
| | - Juntao Gao
- Institute for TCM-X; MOE Key Laboratory of Bioinformatics; Bioinformatics Division, BNRist (Beijing National Research Center for Information Science and Technology); Department of Automation, Tsinghua University, Beijing, 100084, China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China
| | - Zhi Qi
- Center for Quantitative Biology, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Wulan Deng
- Biomedical Pioneering Innovation Center (BIOPIC), Academy for Advanced Interdisciplinary Studies, Beijing Advanced Innovation Center for Genomics (ICG), Peking-Tsinghua Center for Life Sciences (CLS), School of Life Sciences, Peking University, Beijing, 100871, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
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21
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Dehingia B, Milewska M, Janowski M, Pękowska A. CTCF shapes chromatin structure and gene expression in health and disease. EMBO Rep 2022; 23:e55146. [PMID: 35993175 PMCID: PMC9442299 DOI: 10.15252/embr.202255146] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/31/2022] [Accepted: 07/14/2022] [Indexed: 11/09/2022] Open
Abstract
CCCTC-binding factor (CTCF) is an eleven zinc finger (ZF), multivalent transcriptional regulator, that recognizes numerous motifs thanks to the deployment of distinct combinations of its ZFs. The great majority of the ~50,000 genomic locations bound by the CTCF protein in a given cell type is intergenic, and a fraction of these sites overlaps with transcriptional enhancers. Furthermore, a proportion of the regions bound by CTCF intersect genes and promoters. This suggests multiple ways in which CTCF may impact gene expression. At promoters, CTCF can directly affect transcription. At more distal sites, CTCF may orchestrate interactions between regulatory elements and help separate eu- and heterochromatic areas in the genome, exerting a chromatin barrier function. In this review, we outline how CTCF contributes to the regulation of the three-dimensional structure of chromatin and the formation of chromatin domains. We discuss how CTCF binding and architectural functions are regulated. We examine the literature implicating CTCF in controlling gene expression in development and disease both by acting as an insulator and a factor facilitating regulatory elements to efficiently interact with each other in the nuclear space.
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Affiliation(s)
- Bondita Dehingia
- Dioscuri Centre for Chromatin Biology and Epigenomics, Nencki Institute of Experimental BiologyPolish Academy of SciencesWarsawPoland
| | - Małgorzata Milewska
- Dioscuri Centre for Chromatin Biology and Epigenomics, Nencki Institute of Experimental BiologyPolish Academy of SciencesWarsawPoland
| | - Marcin Janowski
- Dioscuri Centre for Chromatin Biology and Epigenomics, Nencki Institute of Experimental BiologyPolish Academy of SciencesWarsawPoland
| | - Aleksandra Pękowska
- Dioscuri Centre for Chromatin Biology and Epigenomics, Nencki Institute of Experimental BiologyPolish Academy of SciencesWarsawPoland
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22
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Jeppsson K, Sakata T, Nakato R, Milanova S, Shirahige K, Björkegren C. Cohesin-dependent chromosome loop extrusion is limited by transcription and stalled replication forks. SCIENCE ADVANCES 2022; 8:eabn7063. [PMID: 35687682 PMCID: PMC9187231 DOI: 10.1126/sciadv.abn7063] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 12/15/2021] [Accepted: 04/27/2022] [Indexed: 05/31/2023]
Abstract
Genome function depends on regulated chromosome folding, and loop extrusion by the protein complex cohesin is essential for this multilayered organization. The chromosomal positioning of cohesin is controlled by transcription, and the complex also localizes to stalled replication forks. However, the role of transcription and replication in chromosome looping remains unclear. Here, we show that reduction of chromosome-bound RNA polymerase weakens normal cohesin loop extrusion boundaries, allowing cohesin to form new long-range chromosome cis interactions. Stress response genes induced by transcription inhibition are also shown to act as new loop extrusion boundaries. Furthermore, cohesin loop extrusion during early S phase is jointly controlled by transcription and replication units. Together, the results reveal that replication and transcription machineries are chromosome-folding regulators that block the progression of loop-extruding cohesin, opening for new perspectives on cohesin's roles in genome function and stability.
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Affiliation(s)
- Kristian Jeppsson
- Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden
- Institute for Quantitative Bioscience, Tokyo University, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Toyonori Sakata
- Institute for Quantitative Bioscience, Tokyo University, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Ryuichiro Nakato
- Institute for Quantitative Bioscience, Tokyo University, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Stefina Milanova
- Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden
| | - Katsuhiko Shirahige
- Institute for Quantitative Bioscience, Tokyo University, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Camilla Björkegren
- Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83 Huddinge, Sweden
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77 Stockholm, Sweden
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23
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Misiura A, Dutta C, Leung W, Zepeda O J, Terlier T, Landes CF. The competing influence of surface roughness, hydrophobicity, and electrostatics on protein dynamics on a self-assembled monolayer. J Chem Phys 2022; 156:094707. [DOI: 10.1063/5.0078797] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Surface morphology, in addition to hydrophobic and electrostatic effects, can alter how proteins interact with solid surfaces. Understanding the heterogeneous dynamics of protein adsorption on surfaces with varying roughness is experimentally challenging. In this work, we use single-molecule fluorescence microscopy to study the adsorption of α-lactalbumin protein on the glass substrate covered with a self-assembled monolayer (SAM) with varying surface concentrations. Two distinct interaction mechanisms are observed: localized adsorption/desorption and continuous-time random walk (CTRW). We investigate the origin of these two populations by simultaneous single-molecule imaging of substrates with both bare glass and SAM-covered regions. SAM-covered areas of substrates are found to promote CTRW, whereas glass surfaces promote localized motion. Contact angle measurements and atomic force microscopy imaging show that increasing SAM concentration results in both increasing hydrophobicity and surface roughness. These properties lead to two opposing effects: increasing hydrophobicity promotes longer protein flights, but increasing surface roughness suppresses protein dynamics resulting in shorter residence times. Our studies suggest that controlling hydrophobicity and roughness, in addition to electrostatics, as independent parameters could provide a means to tune desirable or undesirable protein interactions with surfaces.
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Affiliation(s)
| | - Chayan Dutta
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
| | - Wesley Leung
- Applied Physics Graduate Program, Rice University, Houston, Texas 77005, USA
| | - Jorge Zepeda O
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
| | - Tanguy Terlier
- SIMS Laboratory, Shared Equipment Authority, Rice University, Houston, Texas 77005, USA
| | - Christy F. Landes
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
- Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, USA
- Smalley-Curl Institute, Rice University, Houston, Texas 77005, USA
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24
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Chen YJC, Koutelou E, Dent SY. Now open: Evolving insights to the roles of lysine acetylation in chromatin organization and function. Mol Cell 2022; 82:716-727. [PMID: 35016034 PMCID: PMC8857060 DOI: 10.1016/j.molcel.2021.12.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 11/30/2021] [Accepted: 12/06/2021] [Indexed: 12/17/2022]
Abstract
Protein acetylation is conserved across phylogeny and has been recognized as one of the most prominent post-translational modifications since its discovery nearly 60 years ago. Histone acetylation is an active mark characteristic of open chromatin, but acetylation on specific lysine residues and histone variants occurs in different biological contexts and can confer various outcomes. The significance of acetylation events is indicated by the associations of lysine acetyltransferases, deacetylases, and acetyl-lysine readers with developmental disorders and pathologies. Recent advances have uncovered new roles of acetylation regulators in chromatin-centric events, which emphasize the complexity of these functional networks. In this review, we discuss mechanisms and dynamics of acetylation in chromatin organization and DNA-templated processes, including gene transcription and DNA repair and replication.
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Affiliation(s)
- Ying-Jiun C. Chen
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Evangelia Koutelou
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sharon Y.R. Dent
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Correspondence:
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25
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Enhancer-promoter interactions and transcription are largely maintained upon acute loss of CTCF, cohesin, WAPL or YY1. Nat Genet 2022; 54:1919-1932. [PMID: 36471071 PMCID: PMC9729117 DOI: 10.1038/s41588-022-01223-8] [Citation(s) in RCA: 105] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 10/11/2022] [Indexed: 12/12/2022]
Abstract
It remains unclear why acute depletion of CTCF (CCCTC-binding factor) and cohesin only marginally affects expression of most genes despite substantially perturbing three-dimensional (3D) genome folding at the level of domains and structural loops. To address this conundrum, we used high-resolution Micro-C and nascent transcript profiling in mouse embryonic stem cells. We find that enhancer-promoter (E-P) interactions are largely insensitive to acute (3-h) depletion of CTCF, cohesin or WAPL. YY1 has been proposed as a structural regulator of E-P loops, but acute YY1 depletion also had minimal effects on E-P loops, transcription and 3D genome folding. Strikingly, live-cell, single-molecule imaging revealed that cohesin depletion reduced transcription factor (TF) binding to chromatin. Thus, although CTCF, cohesin, WAPL or YY1 is not required for the short-term maintenance of most E-P interactions and gene expression, our results suggest that cohesin may facilitate TFs to search for and bind their targets more efficiently.
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26
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Maresca M, Liu NQ, de Wit E. Acute Protein Depletion Strategies to Functionally Dissect the 3D Genome. Methods Mol Biol 2022; 2532:311-331. [PMID: 35867256 DOI: 10.1007/978-1-0716-2497-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The organization of the genome inside the nucleus facilitates many nuclear processes. Because the nuclear genome is highly dynamic and often regulated by essential proteins, rapid depletion strategies are necessary to perform loss-of-function analyses. Fortunately, in recent years, various methods have been developed to manipulate the cellular levels of a protein directly and acutely. Here, we describe different methods that have been developed to rapidly deplete proteins from cells, with a focus on auxin inducible degron and dTAG methods, as these are most commonly used in 3D genome organization studies. We outline best practices for designing a knockin strategy, as well as generation and validation of knockin cell lines. Acute depletion strategies have been transformative for the study of the 3D genome and will be important tools for delineating the processes and factors that determine organization of the genome inside the nucleus.
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Affiliation(s)
- Michela Maresca
- Division Gene Regulation, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Ning Qing Liu
- Division Gene Regulation, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Elzo de Wit
- Division Gene Regulation, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands.
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27
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Lee R, Kang MK, Kim YJ, Yang B, Shim H, Kim S, Kim K, Yang CM, Min BG, Jung WJ, Lee EC, Joo JS, Park G, Cho WK, Kim HP. CTCF-mediated chromatin looping provides a topological framework for the formation of phase-separated transcriptional condensates. Nucleic Acids Res 2021; 50:207-226. [PMID: 34931241 PMCID: PMC8855298 DOI: 10.1093/nar/gkab1242] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/22/2021] [Accepted: 12/03/2021] [Indexed: 12/31/2022] Open
Abstract
CTCF is crucial to the organization of mammalian genomes into loop structures. According to recent studies, the transcription apparatus is compartmentalized and concentrated at super-enhancers to form phase-separated condensates and drive the expression of cell-identity genes. However, it remains unclear whether and how transcriptional condensates are coupled to higher-order chromatin organization. Here, we show that CTCF is essential for RNA polymerase II (Pol II)-mediated chromatin interactions, which occur as hyperconnected spatial clusters at super-enhancers. We also demonstrate that CTCF clustering, unlike Pol II clustering, is independent of liquid-liquid phase-separation and resistant to perturbation of transcription. Interestingly, clusters of Pol II, BRD4, and MED1 were found to dissolve upon CTCF depletion, but were reinstated upon restoration of CTCF, suggesting a potent instructive function for CTCF in the formation of transcriptional condensates. Overall, we provide evidence suggesting that CTCF-mediated chromatin looping acts as an architectural prerequisite for the assembly of phase-separated transcriptional condensates.
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Affiliation(s)
- Ryanggeun Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.,College of Natural Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
| | - Moo-Koo Kang
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Yong-Jin Kim
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Bobae Yang
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Hwanyong Shim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
| | - Sugyung Kim
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Kyungwoo Kim
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Chul Min Yang
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Byeong-Gyu Min
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
| | - Woong-Jae Jung
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Eun-Chong Lee
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Jung-Sik Joo
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
| | - Gunhee Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
| | - Won-Ki Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.,KI for Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea
| | - Hyoung-Pyo Kim
- Department of Environmental Medical Biology, Institute of Tropical Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.,Yonsei Genome Center, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea
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28
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Zhang S, Übelmesser N, Josipovic N, Forte G, Slotman JA, Chiang M, Gothe HJ, Gusmao EG, Becker C, Altmüller J, Houtsmuller AB, Roukos V, Wendt KS, Marenduzzo D, Papantonis A. RNA polymerase II is required for spatial chromatin reorganization following exit from mitosis. SCIENCE ADVANCES 2021; 7:eabg8205. [PMID: 34678064 PMCID: PMC8535795 DOI: 10.1126/sciadv.abg8205] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Mammalian chromosomes are three-dimensional entities shaped by converging and opposing forces. Mitotic cell division induces marked chromosome condensation, but following reentry into the G1 phase of the cell cycle, chromosomes reestablish their interphase organization. Here, we tested the role of RNA polymerase II (RNAPII) in this transition using a cell line that allows its auxin-mediated degradation. In situ Hi-C showed that RNAPII is required for both compartment and loop establishment following mitosis. RNAPs often counteract loop extrusion, and in their absence, longer and more prominent loops arose. Evidence from chromatin binding, super-resolution imaging, and in silico modeling allude to these effects being a result of RNAPII-mediated cohesin loading upon G1 reentry. Our findings reconcile the role of RNAPII in gene expression with that in chromatin architecture.
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Affiliation(s)
- Shu Zhang
- Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Nadine Übelmesser
- Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Natasa Josipovic
- Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Giada Forte
- School of Physics and Astronomy, University of Edinburgh, EH9 3FD Edinburgh, UK
| | - Johan A. Slotman
- Optical Imaging Centre, Erasmus Medical Center, 3015 GD Rotterdam, Netherlands
| | - Michael Chiang
- School of Physics and Astronomy, University of Edinburgh, EH9 3FD Edinburgh, UK
| | | | - Eduardo Gade Gusmao
- Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Christian Becker
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | | | | | - Kerstin S. Wendt
- Department of Cell Biology, Erasmus Medical Center, 3015 GD Rotterdam, Netherlands
| | - Davide Marenduzzo
- School of Physics and Astronomy, University of Edinburgh, EH9 3FD Edinburgh, UK
| | - Argyris Papantonis
- Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne, Germany
- Corresponding author.
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29
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Tallan A, Stanton BZ. Inducible Protein Degradation to Understand Genome Architecture. Biochemistry 2021; 60:2387-2396. [PMID: 34292716 DOI: 10.1021/acs.biochem.1c00306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We review exciting recent advances in protein degradation, with a focus on chromatin structure. In our analysis of the literature, we highlight studies of kinetic control of protein stability for cohesin, condensin, ATP-dependent chromatin remodeling, and pioneer transcription factors. With new connections emerging between chromatin remodeling and genome structure, we anticipate exciting developments at the intersection of these topics to be revealed in the coming years. Moreover, we pay special attention to the 20-year anniversary of PROTACs, with an overview of E3 ligase/target pairings and central questions that might lead to the next generation of PROTACs with an expanded scope and generality. While steady-state experimental measurements with constitutive genome editing are impactful, we highlight complementary approaches for rapid kinetic protein degradation to uncover early targeting functions and to understand the central determinants of genome structure-function relationships.
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Affiliation(s)
- Alexi Tallan
- Abigail Wexner Research Institute, Nationwide Children's Hospital, Center for Childhood Cancer and Blood Diseases, 700 Children's Drive, Columbus, Ohio 43205, United States.,Molecular, Cellular, and Developmental Biology Program, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210, United States
| | - Benjamin Z Stanton
- Abigail Wexner Research Institute, Nationwide Children's Hospital, Center for Childhood Cancer and Blood Diseases, 700 Children's Drive, Columbus, Ohio 43205, United States.,Molecular, Cellular, and Developmental Biology Program, The Ohio State University, 484 West 12th Avenue, Columbus, Ohio 43210, United States.,Department of Pediatrics, The Ohio State University College of Medicine, 370 West 9th Avenue, Columbus, Ohio 43210, United States.,Department of Biological Chemistry and Pharmacology, The Ohio State University College of Medicine, 370 West 9th Avenue, Columbus, Ohio 43210, United States
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30
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Wagh K, Garcia DA, Upadhyaya A. Phase separation in transcription factor dynamics and chromatin organization. Curr Opin Struct Biol 2021; 71:148-155. [PMID: 34303933 DOI: 10.1016/j.sbi.2021.06.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 06/16/2021] [Indexed: 02/07/2023]
Abstract
Studies over the past decade have highlighted the key role of liquid-liquid phase separation in cellular organization and function. Dynamic compartmentalization of transcription factors and coactivators by such phase-separated condensates regulates the assembly of transcriptional machinery at genomic loci. Although rapid advances in microscopy have demonstrated the ubiquity of such condensates, a rigorous characterization of the physics of phase separation in transcription remains to be carried out. In this review, we discuss theoretical and experimental evidence for biomolecular condensates as dynamic regulators of transcription. Looking beyond, we highlight functional consequences for transcription factor dynamics and gene expression and discuss potential pitfalls of misclassifying biomolecular condensates as liquid droplets in the absence of a rigorous physical description.
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Affiliation(s)
- Kaustubh Wagh
- Department of Physics, University of Maryland, College Park, MD, 20742, USA; Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - David A Garcia
- Department of Physics, University of Maryland, College Park, MD, 20742, USA; Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, MD, 20742, USA; Institute for Physical Science and Technology, University of Maryland, College Park, MD, 20742, USA.
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31
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Wang W, Gao L, Ye Y, Gao Y. CCIP: Predicting CTCF-mediated chromatin loops with transitivity. Bioinformatics 2021; 37:4635-4642. [PMID: 34289010 PMCID: PMC8665748 DOI: 10.1093/bioinformatics/btab534] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/18/2021] [Accepted: 07/19/2021] [Indexed: 11/14/2022] Open
Abstract
Motivation CTCF-mediated chromatin loops underlie the formation of topological associating domains and serve as the structural basis for transcriptional regulation. However, the formation mechanism of these loops remains unclear, and the genome-wide mapping of these loops is costly and difficult. Motivated by the recent studies on the formation mechanism of CTCF-mediated loops, we studied the possibility of making use of transitivity-related information of interacting CTCF anchors to predict CTCF loops computationally. In this context, transitivity arises when two CTCF anchors interact with the same third anchor by the loop extrusion mechanism and bring themselves close to each other spatially to form an indirect loop. Results To determine whether transitivity is informative for predicting CTCF loops and to obtain an accurate and low-cost predicting method, we proposed a two-stage random-forest-based machine learning method, CTCF-mediated Chromatin Interaction Prediction (CCIP), to predict CTCF-mediated chromatin loops. Our two-stage learning approach makes it possible for us to train a prediction model by taking advantage of transitivity-related information as well as functional genome data and genomic data. Experimental studies showed that our method predicts CTCF-mediated loops more accurately than other methods and that transitivity, when used as a properly defined attribute, is informative for predicting CTCF loops. Furthermore, we found that transitivity explains the formation of tandem CTCF loops and facilitates enhancer–promoter interactions. Our work contributes to the understanding of the formation mechanism and function of CTCF-mediated chromatin loops. Availability and implementation The source code of CCIP can be accessed at: https://github.com/GaoLabXDU/CCIP. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Weibing Wang
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
| | - Lin Gao
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
| | - Yusen Ye
- School of Computer Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China
| | - Yong Gao
- Department of Computer Science, The University of British Columbia Okanagan, Kelowna, BC, V1V 1V5, Canada
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32
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Xie L, Liu Z. Single-cell imaging of genome organization and dynamics. Mol Syst Biol 2021; 17:e9653. [PMID: 34232558 PMCID: PMC8262488 DOI: 10.15252/msb.20209653] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/13/2021] [Accepted: 04/23/2021] [Indexed: 12/28/2022] Open
Abstract
Probing the architecture, mechanism, and dynamics of genome folding is fundamental to our understanding of genome function in homeostasis and disease. Most chromosome conformation capture studies dissect the genome architecture with population- and time-averaged snapshots and thus have limited capabilities to reveal 3D nuclear organization and dynamics at the single-cell level. Here, we discuss emerging imaging techniques ranging from light microscopy to electron microscopy that enable investigation of genome folding and dynamics at high spatial and temporal resolution. Results from these studies complement genomic data, unveiling principles underlying the spatial arrangement of the genome and its potential functional links to diverse biological activities in the nucleus.
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Affiliation(s)
- Liangqi Xie
- Janelia Research CampusHoward Hughes Medical InstituteAshburnVAUSA
| | - Zhe Liu
- Janelia Research CampusHoward Hughes Medical InstituteAshburnVAUSA
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33
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Li J, Pertsinidis A. New insights into promoter-enhancer communication mechanisms revealed by dynamic single-molecule imaging. Biochem Soc Trans 2021; 49:1299-1309. [PMID: 34060610 PMCID: PMC8325597 DOI: 10.1042/bst20200963] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 01/10/2023]
Abstract
Establishing cell-type-specific gene expression programs relies on the action of distal enhancers, cis-regulatory elements that can activate target genes over large genomic distances - up to Mega-bases away. How distal enhancers physically relay regulatory information to target promoters has remained a mystery. Here, we review the latest developments and insights into promoter-enhancer communication mechanisms revealed by live-cell, real-time single-molecule imaging approaches.
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Affiliation(s)
- Jieru Li
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, NY 10065, USA
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34
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Henrikus SS, Costa A. Towards a Structural Mechanism for Sister Chromatid Cohesion Establishment at the Eukaryotic Replication Fork. BIOLOGY 2021; 10:466. [PMID: 34073213 PMCID: PMC8229022 DOI: 10.3390/biology10060466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/23/2022]
Abstract
Cohesion between replicated chromosomes is essential for chromatin dynamics and equal segregation of duplicated genetic material. In the G1 phase, the ring-shaped cohesin complex is loaded onto duplex DNA, enriching at replication start sites, or "origins". During the same phase of the cell cycle, and also at the origin sites, two MCM helicases are loaded as symmetric double hexamers around duplex DNA. During the S phase, and through the action of replication factors, cohesin switches from encircling one parental duplex DNA to topologically enclosing the two duplicated DNA filaments, which are known as sister chromatids. Despite its vital importance, the structural mechanism leading to sister chromatid cohesion establishment at the replication fork is mostly elusive. Here we review the current understanding of the molecular interactions between the replication machinery and cohesin, which support sister chromatid cohesion establishment and cohesin function. In particular, we discuss how cryo-EM is shedding light on the mechanisms of DNA replication and cohesin loading processes. We further expound how frontier cryo-EM approaches, combined with biochemistry and single-molecule fluorescence assays, can lead to understanding the molecular basis of sister chromatid cohesion establishment at the replication fork.
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Affiliation(s)
| | - Alessandro Costa
- Macromolecular Machines Laboratory, The Francis Crick Institute, London NW1 1AT, UK;
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35
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Ryu JK, Bouchoux C, Liu HW, Kim E, Minamino M, de Groot R, Katan AJ, Bonato A, Marenduzzo D, Michieletto D, Uhlmann F, Dekker C. Bridging-induced phase separation induced by cohesin SMC protein complexes. SCIENCE ADVANCES 2021; 7:eabe5905. [PMID: 33568486 PMCID: PMC7875533 DOI: 10.1126/sciadv.abe5905] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/18/2020] [Indexed: 05/04/2023]
Abstract
Structural maintenance of chromosome (SMC) protein complexes are able to extrude DNA loops. While loop extrusion constitutes a fundamental building block of chromosomes, other factors may be equally important. Here, we show that yeast cohesin exhibits pronounced clustering on DNA, with all the hallmarks of biomolecular condensation. DNA-cohesin clusters exhibit liquid-like behavior, showing fusion of clusters, rapid fluorescence recovery after photobleaching and exchange of cohesin with the environment. Strikingly, the in vitro clustering is DNA length dependent, as cohesin forms clusters only on DNA exceeding 3 kilo-base pairs. We discuss how bridging-induced phase separation, a previously unobserved type of biological condensation, can explain the DNA-cohesin clustering through DNA-cohesin-DNA bridges. We confirm that, in yeast cells in vivo, a fraction of cohesin associates with chromatin in a manner consistent with bridging-induced phase separation. Biomolecular condensation by SMC proteins constitutes a new basic principle by which SMC complexes direct genome organization.
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Affiliation(s)
- Je-Kyung Ryu
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Céline Bouchoux
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
| | - Hon Wing Liu
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
| | - Eugene Kim
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Masashi Minamino
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK
| | - Ralph de Groot
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Allard J Katan
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands
| | - Andrea Bonato
- SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, UK
| | - Davide Marenduzzo
- SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, UK
| | - Davide Michieletto
- SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, UK
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London, UK.
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands.
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Kindrick JD, Mole DR. Hypoxic Regulation of Gene Transcription and Chromatin: Cause and Effect. Int J Mol Sci 2020; 21:E8320. [PMID: 33171917 PMCID: PMC7664190 DOI: 10.3390/ijms21218320] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 12/11/2022] Open
Abstract
Cellular responses to low oxygen (hypoxia) are fundamental to normal physiology and to the pathology of many common diseases. Hypoxia-inducible factor (HIF) is central to this by enhancing the transcriptional activity of many hundreds of genes. The cellular response to HIF is cell-type-specific and is largely governed by the pre-existing epigenetic landscape. Prior to activation, HIF-binding sites and the promoters of HIF-target genes are already accessible, in contact with each other through chromatin looping and display markers of activity. However, hypoxia also modulates the epigenetic environment, both in parallel to and as a consequence of HIF activation. This occurs through a combination of oxygen-sensitive changes in enzyme activity, transcriptional activation of epigenetic modifiers, and localized recruitment to chromatin by HIF and activated RNApol2. These hypoxic changes in the chromatin environment may both contribute to and occur as a consequence of transcriptional regulation. Nevertheless, they have the capacity to both modulate and extend the transcriptional response to hypoxia.
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Affiliation(s)
| | - David R. Mole
- NDM Research Building, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7FZ, UK;
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