1
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Whitney PH, Lionnet T. The method in the madness: Transcriptional control from stochastic action at the single-molecule scale. Curr Opin Struct Biol 2024; 87:102873. [PMID: 38954990 DOI: 10.1016/j.sbi.2024.102873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 05/07/2024] [Accepted: 06/05/2024] [Indexed: 07/04/2024]
Abstract
Cell states result from the ordered activation of gene expression by transcription factors. Transcription factors face opposing design constraints: they need to be dynamic to trigger rapid cell state transitions, but also stable enough to maintain terminal cell identities indefinitely. Recent progress in live-cell single-molecule microscopy has helped define the biophysical principles underlying this paradox. Beyond transcription factor activity, single-molecule experiments have revealed that at nearly every level of transcription regulation, control emerges from multiple short-lived stochastic interactions, rather than deterministic, stable interactions typical of other biochemical pathways. This architecture generates consistent outcomes that can be rapidly choreographed. Here, we highlight recent results that demonstrate how order in transcription regulation emerges from the apparent molecular-scale chaos and discuss remaining conceptual challenges.
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Affiliation(s)
- Peter H Whitney
- Institute for Systems Genetics, New York University School of Medicine, New York, NY 10016, USA; Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - Timothée Lionnet
- Institute for Systems Genetics, New York University School of Medicine, New York, NY 10016, USA; Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA; Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY 11201, USA.
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2
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Yang JH, Hansen AS. Enhancer selectivity in space and time: from enhancer-promoter interactions to promoter activation. Nat Rev Mol Cell Biol 2024; 25:574-591. [PMID: 38413840 DOI: 10.1038/s41580-024-00710-6] [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] [Accepted: 01/30/2024] [Indexed: 02/29/2024]
Abstract
The primary regulators of metazoan gene expression are enhancers, originally functionally defined as DNA sequences that can activate transcription at promoters in an orientation-independent and distance-independent manner. Despite being crucial for gene regulation in animals, what mechanisms underlie enhancer selectivity for promoters, and more fundamentally, how enhancers interact with promoters and activate transcription, remain poorly understood. In this Review, we first discuss current models of enhancer-promoter interactions in space and time and how enhancers affect transcription activation. Next, we discuss different mechanisms that mediate enhancer selectivity, including repression, biochemical compatibility and regulation of 3D genome structure. Through 3D polymer simulations, we illustrate how the ability of 3D genome folding mechanisms to mediate enhancer selectivity strongly varies for different enhancer-promoter interaction mechanisms. Finally, we discuss how recent technical advances may provide new insights into mechanisms of enhancer-promoter interactions and how technical biases in methods such as Hi-C and Micro-C and imaging techniques may affect their interpretation.
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Affiliation(s)
- Jin H Yang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, Cambridge, MA, USA
| | - Anders S Hansen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Koch Institute for Integrative Cancer Research, Cambridge, MA, USA.
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3
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Lakadamyali M. From feulgen to modern methods: marking a century of DNA imaging advances. Histochem Cell Biol 2024; 162:13-22. [PMID: 38753186 DOI: 10.1007/s00418-024-02291-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2024] [Indexed: 07/07/2024]
Abstract
The mystery of how human DNA is compactly packaged into a nucleus-a space a hundred thousand times smaller-while still allowing for the regulation of gene function, has long been one of the greatest enigmas in cell biology. This puzzle is gradually being solved, thanks in part to the advent of new technologies. Among these, innovative genome-labeling techniques combined with high-resolution imaging methods have been pivotal. These methods facilitate the visualization of DNA within intact nuclei and have significantly contributed to our current understanding of genome organization. This review will explore various labeling and imaging approaches that are revolutionizing our understanding of the three-dimensional organization of the genome, shedding light on the relationship between its structure and function.
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Affiliation(s)
- Melike Lakadamyali
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.
- Perelman School of Medicine, Epigenetics Institute, University of Pennsylvania, Philadelphia, USA.
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4
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Presman DM, Benítez B, Lafuente AL, Vázquez Lareu A. Chromatin structure and dynamics: one nucleosome at a time. Histochem Cell Biol 2024; 162:79-90. [PMID: 38607419 DOI: 10.1007/s00418-024-02281-1] [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] [Accepted: 03/19/2024] [Indexed: 04/13/2024]
Abstract
Eukaryotic genomes store information on many levels, including their linear DNA sequence, the posttranslational modifications of its constituents (epigenetic modifications), and its three-dimensional folding. Understanding how this information is stored and read requires multidisciplinary collaborations from many branches of science beyond biology, including physics, chemistry, and computer science. Concurrent recent developments in all these areas have enabled researchers to image the genome with unprecedented spatial and temporal resolution. In this review, we focus on what single-molecule imaging and tracking of individual proteins in live cells have taught us about chromatin structure and dynamics. Starting with the basics of single-molecule tracking (SMT), we describe some advantages over in situ imaging techniques and its current limitations. Next, we focus on single-nucleosome studies and what they have added to our current understanding of the relationship between chromatin dynamics and transcription. In celebration of Robert Feulgen's ground-breaking discovery that allowed us to start seeing the genome, we discuss current models of chromatin structure and future challenges ahead.
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Affiliation(s)
- Diego M Presman
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.
| | - Belén Benítez
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
- Instituto de Química Biológica (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
| | - Agustina L Lafuente
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
| | - Alejo Vázquez Lareu
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
- Instituto de Química Biológica (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina
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5
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Zhang LL, Liu JX. 3D chromatin reorganization during stress responses in plants. Sci Bull (Beijing) 2024; 69:847-849. [PMID: 38278707 DOI: 10.1016/j.scib.2024.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2024]
Affiliation(s)
- Lin-Lin Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Life Sciences, Zhejiang University, Hangzhou 310027, China
| | - Jian-Xiang Liu
- State Key Laboratory of Plant Environmental Resilience, College of Life Sciences, Zhejiang University, Hangzhou 310027, China.
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6
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Lizana L, Schwartz YB. The scales, mechanisms, and dynamics of the genome architecture. SCIENCE ADVANCES 2024; 10:eadm8167. [PMID: 38598632 PMCID: PMC11006219 DOI: 10.1126/sciadv.adm8167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 03/06/2024] [Indexed: 04/12/2024]
Abstract
Even when split into several chromosomes, DNA molecules that make up our genome are too long to fit into the cell nuclei unless massively folded. Such folding must accommodate the need for timely access to selected parts of the genome by transcription factors, RNA polymerases, and DNA replication machinery. Here, we review our current understanding of the genome folding inside the interphase nuclei. We consider the resulting genome architecture at three scales with a particular focus on the intermediate (meso) scale and summarize the insights gained from recent experimental observations and diverse computational models.
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Affiliation(s)
- Ludvig Lizana
- Integrated Science Lab, Department of Physics, Umeå University, Umeå, Sweden
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7
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Zülske T, Attou A, Groß L, Hörl D, Harz H, Wedemann G. Nucleosome spacing controls chromatin spatial structure and accessibility. Biophys J 2024; 123:847-857. [PMID: 38419332 PMCID: PMC10995425 DOI: 10.1016/j.bpj.2024.02.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/31/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024] Open
Abstract
Recent research highlights the significance of the three-dimensional structure of chromatin in regulating various cellular processes, particularly transcription. This is achieved through dynamic chromatin structures that facilitate long-range contacts and control spatial accessibility. Chromatin consists of DNA and a variety of proteins, of which histones play an essential structural role by forming nucleosomes. Extensive experimental and theoretical research in recent decades has yielded conflicting results about key factors that regulate the spatial structure of chromatin, which remains enigmatic. By using a computer model that allows us to simulate chromatin volumes containing physiological nucleosome concentrations, we investigated whether nucleosome spacing or nucleosome density is fundamental for three-dimensional chromatin accessibility. Unexpectedly, the regularity of the nucleosome spacing is crucial for determining the accessibility of the chromatin network to diffusive processes, whereas variation in nucleosome concentrations has only minor effects. Using only the basic physical properties of DNA and nucleosomes was sufficient to generate chromatin structures consistent with published electron microscopy data. Contrary to other work, we found that nucleosome density did not substantially alter the properties of chromatin fibers or contact probabilities of genomic loci. No breakup of fiber-like structures was observed at high molar density. These findings challenge previous assumptions and highlight the importance of nucleosome spacing as a key driver of chromatin organization. These results identified changes in nucleosome spacing as a tentative mechanism for altering the spatial chromatin structure and thus genomic functions.
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Affiliation(s)
- Tilo Zülske
- Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany
| | - Aymen Attou
- Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany; Human Biology & BioImaging, Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Laurens Groß
- Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany
| | - David Hörl
- Human Biology & BioImaging, Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Hartmann Harz
- Human Biology & BioImaging, Faculty of Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Gero Wedemann
- Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany.
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8
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Hümpfer N, Thielhorn R, Ewers H. Expanding boundaries - a cell biologist's guide to expansion microscopy. J Cell Sci 2024; 137:jcs260765. [PMID: 38629499 PMCID: PMC11058692 DOI: 10.1242/jcs.260765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024] Open
Abstract
Expansion microscopy (ExM) is a revolutionary novel approach to increase resolution in light microscopy. In contrast to super-resolution microscopy methods that rely on sophisticated technological advances, including novel instrumentation, ExM instead is entirely based on sample preparation. In ExM, labeled target molecules in fixed cells are anchored in a hydrogel, which is then physically enlarged by osmotic swelling. The isotropic swelling of the hydrogel pulls the labels apart from one another, and their relative organization can thus be resolved using conventional microscopes even if it was below the diffraction limit of light beforehand. As ExM can additionally benefit from the technical resolution enhancements achieved by super-resolution microscopy, it can reach into the nanometer range of resolution with an astoundingly low degree of error induced by distortion during the physical expansion process. Because the underlying chemistry is well understood and the technique is based on a relatively simple procedure, ExM is easily reproducible in non-expert laboratories and has quickly been adopted to address an ever-expanding spectrum of problems across the life sciences. In this Review, we provide an overview of this rapidly expanding new field, summarize the most important insights gained so far and attempt to offer an outlook on future developments.
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Affiliation(s)
- Nadja Hümpfer
- Department of Biology, Chemistry and Pharmacy, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany
| | - Ria Thielhorn
- Department of Biology, Chemistry and Pharmacy, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany
| | - Helge Ewers
- Department of Biology, Chemistry and Pharmacy, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany
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9
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Chen Z, Snetkova V, Bower G, Jacinto S, Clock B, Dizehchi A, Barozzi I, Mannion BJ, Alcaina-Caro A, Lopez-Rios J, Dickel DE, Visel A, Pennacchio LA, Kvon EZ. Increased enhancer-promoter interactions during developmental enhancer activation in mammals. Nat Genet 2024; 56:675-685. [PMID: 38509385 PMCID: PMC11203181 DOI: 10.1038/s41588-024-01681-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 02/06/2024] [Indexed: 03/22/2024]
Abstract
Remote enhancers are thought to interact with their target promoters via physical proximity, yet the importance of this proximity for enhancer function remains unclear. Here we investigate the three-dimensional (3D) conformation of enhancers during mammalian development by generating high-resolution tissue-resolved contact maps for nearly a thousand enhancers with characterized in vivo activities in ten murine embryonic tissues. Sixty-one percent of developmental enhancers bypass their neighboring genes, which are often marked by promoter CpG methylation. The majority of enhancers display tissue-specific 3D conformations, and both enhancer-promoter and enhancer-enhancer interactions are moderately but consistently increased upon enhancer activation in vivo. Less than 14% of enhancer-promoter interactions form stably across tissues; however, these invariant interactions form in the absence of the enhancer and are likely mediated by adjacent CTCF binding. Our results highlight the general importance of enhancer-promoter physical proximity for developmental gene activation in mammals.
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Affiliation(s)
- Zhuoxin Chen
- Department of Developmental and Cell Biology, School of the Biological Sciences, University of California, Irvine, CA, USA
| | - Valentina Snetkova
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Grace Bower
- Department of Developmental and Cell Biology, School of the Biological Sciences, University of California, Irvine, CA, USA
| | - Sandra Jacinto
- Department of Developmental and Cell Biology, School of the Biological Sciences, University of California, Irvine, CA, USA
| | - Benjamin Clock
- Department of Developmental and Cell Biology, School of the Biological Sciences, University of California, Irvine, CA, USA
| | - Atrin Dizehchi
- Department of Developmental and Cell Biology, School of the Biological Sciences, University of California, Irvine, CA, USA
| | - Iros Barozzi
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Center for Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Brandon J Mannion
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, CA, USA
| | - Ana Alcaina-Caro
- Centro Andaluz de Biología del Desarrollo, CSIC, Universidad Pablo de Olavide, Junta de Andalucía, Seville, Spain
| | - Javier Lopez-Rios
- Centro Andaluz de Biología del Desarrollo, CSIC, Universidad Pablo de Olavide, Junta de Andalucía, Seville, Spain
- School of Health Sciences, Universidad Loyola Andalucía, Seville, Spain
| | - Diane E Dickel
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Octant, Inc, Emeryville, CA, USA
| | - Axel Visel
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
- School of Natural Sciences, University of California, Merced, CA, USA
| | - Len A Pennacchio
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Evgeny Z Kvon
- Department of Developmental and Cell Biology, School of the Biological Sciences, University of California, Irvine, CA, USA.
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10
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Woodworth MA, Lakadamyali M. Toward a comprehensive view of gene architecture during transcription. Curr Opin Genet Dev 2024; 85:102154. [PMID: 38309073 PMCID: PMC10989512 DOI: 10.1016/j.gde.2024.102154] [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: 08/31/2023] [Revised: 12/20/2023] [Accepted: 01/09/2024] [Indexed: 02/05/2024]
Abstract
The activation of genes within the nucleus of eukaryotic cells is a tightly regulated process, orchestrated by a complex interplay of various physical properties and interacting factors. Studying the multitude of components and features that collectively contribute to gene activation has proven challenging due to the complexities of simultaneously visualizing the dynamic and transiently interacting elements that coalesce within the small space occupied by each individual gene. However, various labeling and imaging advances are now starting to overcome this challenge, enabling visualization of gene activation at different lengths and timescales. In this review, we aim to highlight these microscopy-based advances and suggest how they can be combined to provide a comprehensive view of the mechanisms regulating gene activation.
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Affiliation(s)
- Marcus A Woodworth
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Melike Lakadamyali
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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11
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Ryu K, Park G, Cho WK. Emerging insights into transcriptional condensates. Exp Mol Med 2024; 56:820-826. [PMID: 38658705 PMCID: PMC11059374 DOI: 10.1038/s12276-024-01228-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/26/2024] [Accepted: 03/05/2024] [Indexed: 04/26/2024] Open
Abstract
Eukaryotic transcription, a fundamental process that governs cell-specific gene expression, has long been the subject of extensive investigations in the fields of molecular biology, biochemistry, and structural biology. Recent advances in microscopy techniques have led to a fascinating concept known as "transcriptional condensates." These dynamic assemblies are the result of a phenomenon called liquid‒liquid phase separation, which is driven by multivalent interactions between the constituent proteins in cells. The essential proteins associated with transcription are concentrated in transcriptional condensates. Recent studies have shed light on the temporal dynamics of transcriptional condensates and their potential role in enhancing the efficiency of transcription. In this article, we explore the properties of transcriptional condensates, investigate how they evolve over time, and evaluate the significant impact they have on the process of transcription. Furthermore, we highlight innovative techniques that allow us to manipulate these condensates, thus demonstrating their responsiveness to cellular signals and their connection to transcriptional bursting. As our understanding of transcriptional condensates continues to grow, they are poised to revolutionize our understanding of eukaryotic gene regulation.
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Affiliation(s)
- Kwangmin Ryu
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Deahak-ro, Yuseong-gu, Daejeon, 34141, Korea
| | - Gunhee Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Deahak-ro, Yuseong-gu, Daejeon, 34141, Korea
| | - Won-Ki Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Deahak-ro, Yuseong-gu, Daejeon, 34141, Korea.
- KAIST Stem Cell Research Center, Korea Advanced Institute of Science and Technology (KAIST), 291 Deahak-ro, Yuseong-gu, Daejeon, 34141, Korea.
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12
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Valyaeva AA, Sheval EV. Nonspecific Interactions in Transcription Regulation and Organization of Transcriptional Condensates. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:688-700. [PMID: 38831505 DOI: 10.1134/s0006297924040084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 06/05/2024]
Abstract
Eukaryotic cells are characterized by a high degree of compartmentalization of their internal contents, which ensures precise and controlled regulation of intracellular processes. During many processes, including different stages of transcription, dynamic membraneless compartments termed biomolecular condensates are formed. Transcription condensates contain various transcription factors and RNA polymerase and are formed by high- and low-specificity interactions between the proteins, DNA, and nearby RNA. This review discusses recent data demonstrating important role of nonspecific multivalent protein-protein and RNA-protein interactions in organization and regulation of transcription.
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Affiliation(s)
- Anna A Valyaeva
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia.
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
- Department of Cell Biology and Histology, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Eugene V Sheval
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
- Department of Cell Biology and Histology, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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13
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Stortz M, Presman DM, Levi V. Transcriptional condensates: a blessing or a curse for gene regulation? Commun Biol 2024; 7:187. [PMID: 38365945 PMCID: PMC10873363 DOI: 10.1038/s42003-024-05892-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 02/06/2024] [Indexed: 02/18/2024] Open
Abstract
Whether phase-separation is involved in the organization of the transcriptional machinery and if it aids or inhibits the transcriptional process is a matter of intense debate. In this Mini Review, we will cover the current knowledge regarding the role of transcriptional condensates on gene expression regulation. We will summarize the latest discoveries on the relationship between condensate formation, genome organization, and transcriptional activity, focusing on the strengths and weaknesses of the experimental approaches used to interrogate these aspects of transcription in living cells. Finally, we will discuss the challenges for future research.
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Grants
- PICT 2020-00818 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- PICT-2018-1921 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- PICT 2019-0397 Ministry of Science, Technology and Productive Innovation, Argentina | Agencia Nacional de Promoción Científica y Tecnológica (National Agency for Science and Technology, Argentina)
- 20020190100101BA University of Buenos Aires | Secretaría de Ciencia y Técnica, Universidad de Buenos Aires (Secretaría de Ciencia y Técnica de la Universidad de Buenos Aires)
- 2022-11220210100212CO Consejo Nacional de Investigaciones Científicas y Técnicas (National Scientific and Technical Research Council)
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Affiliation(s)
- Martin Stortz
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Diego M Presman
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, C1428EGA, Argentina.
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.
| | - Valeria Levi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.
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14
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Kawasaki K, Fukaya T. Regulatory landscape of enhancer-mediated transcriptional activation. Trends Cell Biol 2024:S0962-8924(24)00020-5. [PMID: 38355349 DOI: 10.1016/j.tcb.2024.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/21/2023] [Accepted: 01/22/2024] [Indexed: 02/16/2024]
Abstract
Enhancers are noncoding regulatory elements that instruct spatial and temporal specificity of gene transcription in response to a variety of intrinsic and extrinsic signals during development. Although it has long been postulated that enhancers physically interact with target promoters through the formation of stable loops, recent studies have changed this static view: sequence-specific transcription factors (TFs) and coactivators are dynamically recruited to enhancers and assemble so-called transcription hubs. Dynamic assembly of transcription hubs appears to serve as a key scaffold to integrate regulatory information encoded by surrounding genome and biophysical properties of transcription machineries. In this review, we outline emerging new models of transcriptional regulation by enhancers and discuss future perspectives.
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Affiliation(s)
- Koji Kawasaki
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Takashi Fukaya
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan; Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.
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15
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Meeussen JVW, Lenstra TL. Time will tell: comparing timescales to gain insight into transcriptional bursting. Trends Genet 2024; 40:160-174. [PMID: 38216391 PMCID: PMC10860890 DOI: 10.1016/j.tig.2023.11.003] [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: 09/13/2023] [Revised: 11/27/2023] [Accepted: 11/27/2023] [Indexed: 01/14/2024]
Abstract
Recent imaging studies have captured the dynamics of regulatory events of transcription inside living cells. These events include transcription factor (TF) DNA binding, chromatin remodeling and modification, enhancer-promoter (E-P) proximity, cluster formation, and preinitiation complex (PIC) assembly. Together, these molecular events culminate in stochastic bursts of RNA synthesis, but their kinetic relationship remains largely unclear. In this review, we compare the timescales of upstream regulatory steps (input) with the kinetics of transcriptional bursting (output) to generate mechanistic models of transcription dynamics in single cells. We highlight open questions and potential technical advances to guide future endeavors toward a quantitative and kinetic understanding of transcription regulation.
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Affiliation(s)
- Joseph V W Meeussen
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066CX, The Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066CX, The Netherlands.
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16
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Barral A, Zaret KS. Pioneer factors: roles and their regulation in development. Trends Genet 2024; 40:134-148. [PMID: 37940484 PMCID: PMC10873006 DOI: 10.1016/j.tig.2023.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
Pioneer factors are a subclass of transcription factors that can bind and initiate opening of silent chromatin regions. Pioneer factors subsequently regulate lineage-specific genes and enhancers and, thus, activate the zygotic genome after fertilization, guide cell fate transitions during development, and promote various forms of human cancers. As such, pioneer factors are useful in directed cell reprogramming. In this review, we define the structural and functional characteristics of pioneer factors, how they bind and initiate opening of closed chromatin regions, and the consequences for chromatin dynamics and gene expression during cell differentiation. We also discuss emerging mechanisms that modulate pioneer factors during development.
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Affiliation(s)
- Amandine Barral
- Institute for Regenerative Medicine and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Boulevard, Philadelphia, PA 19104, USA
| | - Kenneth S Zaret
- Institute for Regenerative Medicine and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Boulevard, Philadelphia, PA 19104, USA.
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17
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Katz LS, Brill G, Wang P, Lambertini L, Zhang P, Haldeman JM, Liu H, Newgard CB, Stewart AF, Garcia-Ocaña A, Scott DK. Transcriptional activation of the Myc gene by glucose in β-cells requires a ChREBP-dependent 3-D chromatin interaction between the Myc and Pvt1 genes. Mol Metab 2024; 79:101848. [PMID: 38042369 PMCID: PMC10714240 DOI: 10.1016/j.molmet.2023.101848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/14/2023] [Accepted: 11/28/2023] [Indexed: 12/04/2023] Open
Abstract
OBJECTIVE All forms of diabetes result from insufficient functional β-cell mass. Thus, achieving the therapeutic goal of expanding β-cell mass requires a better mechanistic understanding of how β-cells proliferate. Glucose is a natural β-cell mitogen that mediates its effects in part through the glucose-responsive transcription factor, carbohydrate response element binding protein (ChREBP) and the anabolic transcription factor, MYC. However, mechanistic details by which glucose activates Myc at the transcriptional level are poorly understood. METHODS Here, siRNA was used to test the role of ChREBP in the glucose response of MYC, ChIP and ChIPseq to identify potential regulatory binding sites, chromatin conformation capture to identify DNA/DNA interactions, and an adenovirus was constructed to expresses x-dCas9 and an sgRNA that specifically disrupts the recruitment of ChREBP to a specific targeted ChoRE. RESULTS We found that ChREBP is essential for glucose-mediated transcriptional induction of Myc, and for increases in Myc mRNA and protein abundance. Further, ChIPseq revealed that the carbohydrate response element (ChoRE) nearest to the Myc transcriptional start site (TSS) is immediately upstream of the gene encoding the lncRNA, Pvt1, 60,000 bp downstream of the Myc gene. Chromatin Conformation Capture (3C) confirmed a glucose-dependent interaction between these two sites. Transduction with an adenovirus expressing x-dCas9 and an sgRNA specifically targeting the highly conserved Pvt1 ChoRE, attenuates ChREBP recruitment, decreases Myc-Pvt1 DNA/DNA interaction, and decreases expression of the Pvt1 and Myc genes in response to glucose. Importantly, isolated and dispersed rat islet cells transduced with the ChoRE-disrupting adenovirus also display specific decreases in ChREBP-dependent, glucose-mediated expression of Pvt1 and Myc, as well as decreased glucose-stimulated β-cell proliferation. CONCLUSIONS The mitogenic glucose response of Myc is mediated via glucose-dependent recruitment of ChREBP to the promoter of the Pvt1 gene and subsequent DNA looping with the Myc promoter.
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Affiliation(s)
- Liora S Katz
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Gabriel Brill
- Pharmacologic Sciences Department, Stony Brook University, Stony Brook, NY, USA(5)
| | - Peng Wang
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Luca Lambertini
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Pili Zhang
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | | | - Hongtao Liu
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | | | - Andrew F Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Adolfo Garcia-Ocaña
- Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA.
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18
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Shivashankar GV. Mechanical forces and the 3D genome. Curr Opin Struct Biol 2023; 83:102728. [PMID: 37948897 DOI: 10.1016/j.sbi.2023.102728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 11/12/2023]
Abstract
Traditionally, the field of genomics has been studied from a biochemical perspective. Besides chemical influences, cells are subject to a variety of mechanical signals from their surrounding tissue microenvironment. These mechanical signals can not only cause changes to a cell's physical structure but can also lead to alterations in their genomes and gene expression programs. Understanding the mechanical control of genome organization and expression may provide a new perspective on gene regulation.
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19
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Park S, Wang X, Li X, Huang X, Fong KC, Yu C, Tran AA, Scipioni L, Dai Z, Huang L, Shi X. Proximity Labeling Expansion Microscopy (PL-ExM) resolves structure of the interactome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.09.566477. [PMID: 38014020 PMCID: PMC10680661 DOI: 10.1101/2023.11.09.566477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Elucidating the spatial relationships within the protein interactome is pivotal to understanding the organization and regulation of protein-protein interactions. However, capturing the 3D architecture of the interactome presents a dual challenge: precise interactome labeling and super-resolution imaging. To bridge this gap, we present the Proximity Labeling Expansion Microscopy (PL-ExM). This innovation combines proximity labeling (PL) to spatially biotinylate interacting proteins with expansion microscopy (ExM) to increase imaging resolution by physically enlarging cells. PL-ExM unveils intricate details of the 3D interactome's spatial layout in cells using standard microscopes, including confocal and Airyscan. Multiplexing PL-ExM imaging was achieved by pairing the PL with immunofluorescence staining. These multicolor images directly visualize how interactome structures position specific proteins in the protein-protein interaction network. Furthermore, PL-ExM stands out as an assessment method to gauge the labeling radius and efficiency of different PL techniques. The accuracy of PL-ExM is validated by our proteomic results from PL mass spectrometry. Thus, PL-ExM is an accessible solution for 3D mapping of the interactome structure and an accurate tool to access PL quality.
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20
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Sept CE, Tak YE, Cerda-Smith CG, Hutchinson HM, Goel V, Blanchette M, Bhakta MS, Hansen AS, Joung JK, Johnstone S, Eyler CE, Aryee MJ. High-resolution CTCF footprinting reveals impact of chromatin state on cohesin extrusion dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.20.563340. [PMID: 37961446 PMCID: PMC10634716 DOI: 10.1101/2023.10.20.563340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
DNA looping is vital for establishing many enhancer-promoter interactions. While CTCF is known to anchor many cohesin-mediated loops, the looped chromatin fiber appears to predominantly exist in a poorly characterized actively extruding state. To better characterize extruding chromatin loop structures, we used CTCF MNase HiChIP data to determine both CTCF binding at high resolution and 3D contact information. Here we present FactorFinder, a tool that identifies CTCF binding sites at near base-pair resolution. We leverage this substantial advance in resolution to determine that the fully extruded (CTCF-CTCF) state is rare genome-wide with locus-specific variation from ~1-10%. We further investigate the impact of chromatin state on loop extrusion dynamics, and find that active enhancers and RNA Pol II impede cohesin extrusion, facilitating an enrichment of enhancer-promoter contacts in the partially extruded loop state. We propose a model of topological regulation whereby the transient, partially extruded states play active roles in transcription.
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Affiliation(s)
- Corriene E Sept
- Department of Biostatistics, Harvard T.H. Chan School of Public Health; Boston, MA 02115, USA
- Department of Data Sciences, Dana-Farber Cancer Institute; Boston, MA 02115, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
| | - Y Esther Tak
- Molecular Pathology Unit, Massachusetts General Hospital; Charlestown, MA 02129, USA
- Department of Pathology, Harvard Medical School; Boston, MA 02115, USA
| | - Christian G Cerda-Smith
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine; Durham, NC 27710, USA
| | - Haley M Hutchinson
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine; Durham, NC 27710, USA
| | - Viraat Goel
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Koch Institute for Integrative Cancer Research; Cambridge, MA 02139, USA
| | - Marco Blanchette
- Dovetail Genomics, Cantata Bio LLC, Scotts Valley, CA 95066, USA
| | - Mital S Bhakta
- Dovetail Genomics, Cantata Bio LLC, Scotts Valley, CA 95066, USA
| | - Anders S Hansen
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA 02139, USA
- Koch Institute for Integrative Cancer Research; Cambridge, MA 02139, USA
| | - J Keith Joung
- Molecular Pathology Unit, Massachusetts General Hospital; Charlestown, MA 02129, USA
- Department of Pathology, Harvard Medical School; Boston, MA 02115, USA
| | - Sarah Johnstone
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
- Department of Pathology, Dana-Farber Cancer Institute; Boston, MA 02215, USA
| | - Christine E Eyler
- Department of Radiation Oncology, Duke University School of Medicine; Durham, NC 27710, USA
- Duke Cancer Institute, Duke University School of Medicine; Durham, NC 27710, USA
| | - Martin J Aryee
- Department of Biostatistics, Harvard T.H. Chan School of Public Health; Boston, MA 02115, USA
- Department of Data Sciences, Dana-Farber Cancer Institute; Boston, MA 02115, USA
- Broad Institute of MIT and Harvard; Cambridge, MA 02142, USA
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21
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Stasevich TJ, Kimura H. An expanded view of transcription. Science 2023; 381:26-27. [PMID: 37410830 DOI: 10.1126/science.adi8187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
A new method expands chromatin to provide detailed images of transcription sites.
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Affiliation(s)
- Timothy J Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Hiroshi Kimura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
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