1
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Yao Q, Zhu L, Shi Z, Banerjee S, Chen C. Topoisomerase-modulated genome-wide DNA supercoiling domains colocalize with nuclear compartments and regulate human gene expression. Nat Struct Mol Biol 2024:10.1038/s41594-024-01377-5. [PMID: 39152238 DOI: 10.1038/s41594-024-01377-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 07/24/2024] [Indexed: 08/19/2024]
Abstract
DNA supercoiling is a biophysical feature of the double helix with a pivotal role in biological processes. However, understanding of DNA supercoiling in the chromatin remains limited. Here, we developed azide-trimethylpsoralen sequencing (ATMP-seq), a DNA supercoiling assay offering quantitative accuracy while minimizing genomic bias and background noise. Using ATMP-seq, we directly visualized transcription-dependent negative and positive twin-supercoiled domains around genes and mapped kilobase-resolution DNA supercoiling throughout the human genome. Remarkably, we discovered megabase-scale supercoiling domains (SDs) across all chromosomes that are modulated mainly by topoisomerases I and IIβ. Transcription activities, but not the consequent supercoiling accumulation in the local region, contribute to SD formation, indicating the long-range propagation of transcription-generated supercoiling. Genome-wide SDs colocalize with A/B compartments in both human and Drosophila cells but are distinct from topologically associating domains (TADs), with negative supercoiling accumulation at TAD boundaries. Furthermore, genome-wide DNA supercoiling varies between cell states and types and regulates human gene expression, underscoring the importance of supercoiling dynamics in chromatin regulation and function.
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Affiliation(s)
- Qian Yao
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Linying Zhu
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zhen Shi
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Subhadra Banerjee
- Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Chongyi Chen
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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2
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Hebenstreit D, Karmakar P. Transcriptional bursting: from fundamentals to novel insights. Biochem Soc Trans 2024:BST20231286. [PMID: 39119657 DOI: 10.1042/bst20231286] [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: 03/25/2024] [Revised: 07/12/2024] [Accepted: 07/30/2024] [Indexed: 08/10/2024]
Abstract
Transcription occurs as irregular bursts in a very wide range of systems, including numerous different species and many genes within these. In this review, we examine the underlying theories, discuss how these relate to experimental measurements, and explore some of the discrepancies that have emerged among various studies. Finally, we consider more recent works that integrate novel concepts, such as the involvement of biomolecular condensates in enhancer-promoter interactions and their effects on the dynamics of transcriptional bursting.
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Affiliation(s)
| | - Pradip Karmakar
- School of Life Sciences, University of Warwick, CV4 7AL Coventry, U.K
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3
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Schofield JA, Hahn S. Transcriptional noise, gene activation, and roles of SAGA and Mediator Tail measured using nucleotide recoding single-cell RNA-seq. Cell Rep 2024; 43:114593. [PMID: 39102335 DOI: 10.1016/j.celrep.2024.114593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 06/29/2024] [Accepted: 07/22/2024] [Indexed: 08/07/2024] Open
Abstract
We describe a time-resolved nascent single-cell RNA sequencing (RNA-seq) approach that measures gene-specific transcriptional noise and the fraction of active genes in S. cerevisiae. Most genes are expressed with near-constitutive behavior, while a subset of genes show high mRNA variance suggestive of transcription bursting. Transcriptional noise is highest in the cofactor/coactivator-redundant (CR) gene class (dependent on both SAGA and TFIID) and strongest in TATA-containing CR genes. Using this approach, we also find that histone gene transcription switches from a low-level, low-noise constitutive mode during M and M/G1 to an activated state in S phase that shows both an increase in the fraction of active promoters and a switch to a noisy and bursty transcription mode. Rapid depletion of cofactors SAGA and MED Tail indicates that both factors play an important role in stimulating the fraction of active promoters at CR genes, with a more modest role in transcriptional noise.
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Affiliation(s)
| | - Steven Hahn
- Fred Hutchinson Cancer Center, Seattle, WA 98109, USA.
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4
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Li S, Vemuri C, Chen C. DNA topology: A central dynamic coordinator in chromatin regulation. Curr Opin Struct Biol 2024; 87:102868. [PMID: 38878530 PMCID: PMC11283972 DOI: 10.1016/j.sbi.2024.102868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 05/15/2024] [Accepted: 05/27/2024] [Indexed: 07/29/2024]
Abstract
Double helical DNA winds around nucleosomes, forming a beads-on-a-string array that further contributes to the formation of high-order chromatin structures. The regulatory components of the chromatin, interacting intricately with DNA, often exploit the topological tension inherent in the DNA molecule. Recent findings shed light on, and simultaneously complicate, the multifaceted roles of DNA topology (also known as DNA supercoiling) in various aspects of chromatin regulation. Different studies may emphasize the dynamics of DNA topological tension across different scales, interacting with diverse chromatin factors such as nucleosomes, nucleic acid motors that propel DNA-tracking processes, and DNA topoisomerases. In this review, we consolidate recent studies and establish connections between distinct scientific discoveries, advancing our current understanding of chromatin regulation mediated by the supercoiling tension of the double helix. Additionally, we explore the implications of DNA topology and DNA topoisomerases in human diseases, along with their potential applications in therapeutic interventions.
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Affiliation(s)
- Shuai Li
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Charan Vemuri
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Chongyi Chen
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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5
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Nemsick S, Hansen AS. Molecular models of bidirectional promoter regulation. Curr Opin Struct Biol 2024; 87:102865. [PMID: 38905929 DOI: 10.1016/j.sbi.2024.102865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/30/2024] [Accepted: 05/27/2024] [Indexed: 06/23/2024]
Abstract
Approximately 11% of human genes are transcribed by a bidirectional promoter (BDP), defined as two genes with <1 kb between their transcription start sites. Despite their evolutionary conservation and enrichment for housekeeping genes and oncogenes, the regulatory role of BDPs remains unclear. BDPs have been suggested to facilitate gene coregulation and/or decrease expression noise. This review discusses these potential regulatory functions through the context of six prospective underlying mechanistic models: a single nucleosome free region, shared transcription factor/regulator binding, cooperative negative supercoiling, bimodal histone marks, joint activation by enhancer(s), and RNA-mediated recruitment of regulators. These molecular mechanisms may act independently and/or cooperatively to facilitate the coregulation and/or decreased expression noise predicted of BDPs.
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Affiliation(s)
- Sarah Nemsick
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; The Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA
| | - Anders S Hansen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; The Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA.
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6
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Yao YM, Miodownik I, O'Hagan MP, Jbara M, Afek A. Deciphering the dynamic code: DNA recognition by transcription factors in the ever-changing genome. Transcription 2024:1-25. [PMID: 39033307 DOI: 10.1080/21541264.2024.2379161] [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: 03/15/2024] [Accepted: 07/03/2024] [Indexed: 07/23/2024] Open
Abstract
Transcription factors (TFs) intricately navigate the vast genomic landscape to locate and bind specific DNA sequences for the regulation of gene expression programs. These interactions occur within a dynamic cellular environment, where both DNA and TF proteins experience continual chemical and structural perturbations, including epigenetic modifications, DNA damage, mechanical stress, and post-translational modifications (PTMs). While many of these factors impact TF-DNA binding interactions, understanding their effects remains challenging and incomplete. This review explores the existing literature on these dynamic changes and their potential impact on TF-DNA interactions.
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Affiliation(s)
- Yumi Minyi Yao
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Irina Miodownik
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Michael P O'Hagan
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Muhammad Jbara
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ariel Afek
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
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7
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Brahmachari S, Tripathi S, Onuchic JN, Levine H. Nucleosomes play a dual role in regulating transcription dynamics. Proc Natl Acad Sci U S A 2024; 121:e2319772121. [PMID: 38968124 PMCID: PMC11252751 DOI: 10.1073/pnas.2319772121] [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: 11/10/2023] [Accepted: 05/31/2024] [Indexed: 07/07/2024] Open
Abstract
Transcription has a mechanical component, as the translocation of the transcription machinery or RNA polymerase (RNAP) on DNA or chromatin is dynamically coupled to the chromatin torsion. This posits chromatin mechanics as a possible regulator of eukaryotic transcription, however, the modes and mechanisms of this regulation are elusive. Here, we first take a statistical mechanics approach to model the torsional response of topology-constrained chromatin. Our model recapitulates the experimentally observed weaker torsional stiffness of chromatin compared to bare DNA and proposes structural transitions of nucleosomes into chirally distinct states as the driver of the contrasting torsional mechanics. Coupling chromatin mechanics with RNAP translocation in stochastic simulations, we reveal a complex interplay of DNA supercoiling and nucleosome dynamics in governing RNAP velocity. Nucleosomes play a dual role in controlling the transcription dynamics. The steric barrier aspect of nucleosomes in the gene body counteracts transcription via hindering RNAP motion, whereas the chiral transitions facilitate RNAP motion via driving a low restoring torque upon twisting the DNA. While nucleosomes with low dissociation rates are typically transcriptionally repressive, highly dynamic nucleosomes offer less of a steric barrier and enhance the transcription elongation dynamics of weakly transcribed genes via buffering DNA twist. We use the model to predict transcription-dependent levels of DNA supercoiling in segments of the budding yeast genome that are in accord with available experimental data. The model unveils a paradigm of DNA supercoiling-mediated interaction between genes and makes testable predictions that will guide experimental design.
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Affiliation(s)
| | - Shubham Tripathi
- PhD Program in Systems, Synthetic, and Physical Biology, Rice University, Houston, TX77005
| | - José N. Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, TX77005
- Department of Physics and Astronomy, Rice University, Houston, TX77005
- Department of Chemistry, Rice University, Houston, TX77005
- Department of Biosciences, Rice University, Houston, TX77005
| | - Herbert Levine
- Center for Theoretical Biological Physics, Northeastern University, Boston, MA02115
- Department of Physics, Northeastern University, Boston, MA02115
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8
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Peterman EL, Ploessl DS, Galloway KE. Accelerating Diverse Cell-Based Therapies Through Scalable Design. Annu Rev Chem Biomol Eng 2024; 15:267-292. [PMID: 38594944 DOI: 10.1146/annurev-chembioeng-100722-121610] [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: 04/11/2024]
Abstract
Augmenting cells with novel, genetically encoded functions will support therapies that expand beyond natural capacity for immune surveillance and tissue regeneration. However, engineering cells at scale with transgenic cargoes remains a challenge in realizing the potential of cell-based therapies. In this review, we introduce a range of applications for engineering primary cells and stem cells for cell-based therapies. We highlight tools and advances that have launched mammalian cell engineering from bioproduction to precision editing of therapeutically relevant cells. Additionally, we examine how transgenesis methods and genetic cargo designs can be tailored for performance. Altogether, we offer a vision for accelerating the translation of innovative cell-based therapies by harnessing diverse cell types, integrating the expanding array of synthetic biology tools, and building cellular tools through advanced genome writing techniques.
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Affiliation(s)
- Emma L Peterman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA;
| | - Deon S Ploessl
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA;
| | - Kate E Galloway
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA;
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9
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Sood V, Holewinski R, Andresson T, Larson DR, Misteli T. Identification of molecular determinants of gene-specific bursting patterns by high-throughput imaging screens. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.597999. [PMID: 38903099 PMCID: PMC11188098 DOI: 10.1101/2024.06.08.597999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Stochastic transcriptional bursting is a universal property of active genes. While different genes exhibit distinct bursting patterns, the molecular mechanisms for gene-specific stochastic bursting are largely unknown. We have developed and applied a high-throughput-imaging based screening strategy to identify cellular factors and molecular mechanisms that determine the bursting behavior of human genes. Focusing on epigenetic regulators, we find that protein acetylation is a strong acute modulator of burst frequency, burst size and heterogeneity of bursting. Acetylation globally affects the Off-time of genes but has gene-specific effects on the On-time. Yet, these effects are not strongly linked to promoter acetylation, which do not correlate with bursting properties, and forced promoter acetylation has variable effects on bursting. Instead, we demonstrate acetylation of the Integrator complex as a key determinant of gene bursting. Specifically, we find that elevated Integrator acetylation decreases bursting frequency. Taken together our results suggest a prominent role of non-histone proteins in determining gene bursting properties, and they identify histone-independent acetylation of a transcription cofactor as an allosteric modulator of bursting via a far-downstream bursting checkpoint.
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Affiliation(s)
- Varun Sood
- National Cancer Institute, Bethesda, MD, USA
| | - Ronald Holewinski
- Protein Characterization Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Thorkell Andresson
- Protein Characterization Laboratory, National Cancer Institute, Frederick, MD, USA
| | | | - Tom Misteli
- National Cancer Institute, Bethesda, MD, USA
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10
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Werner A, Kanhere A, Wahlestedt C, Mattick JS. Natural antisense transcripts as versatile regulators of gene expression. Nat Rev Genet 2024:10.1038/s41576-024-00723-z. [PMID: 38632496 DOI: 10.1038/s41576-024-00723-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2024] [Indexed: 04/19/2024]
Abstract
Long non-coding RNAs (lncRNAs) are emerging as a major class of gene products that have central roles in cell and developmental biology. Natural antisense transcripts (NATs) are an important subset of lncRNAs that are expressed from the opposite strand of protein-coding and non-coding genes and are a genome-wide phenomenon in both eukaryotes and prokaryotes. In eukaryotes, a myriad of NATs participate in regulatory pathways that affect expression of their cognate sense genes. Recent developments in the study of NATs and lncRNAs and large-scale sequencing and bioinformatics projects suggest that whether NATs regulate expression, splicing, stability or translation of the sense transcript is influenced by the pattern and degrees of overlap between the sense-antisense pair. Moreover, epigenetic gene regulatory mechanisms prevail in somatic cells whereas mechanisms dependent on the formation of double-stranded RNA intermediates are prevalent in germ cells. The modulating effects of NATs on sense transcript expression make NATs rational targets for therapeutic interventions.
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Affiliation(s)
| | | | | | - John S Mattick
- University of New South Wales, Sydney, New South Wales, Australia
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11
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Kindongo O, Lieb G, Skaggs B, Dusserre Y, Vincenzetti V, Pelet S. Implication of polymerase recycling for nascent transcript quantification by live cell imaging. Yeast 2024; 41:279-294. [PMID: 38389243 DOI: 10.1002/yea.3929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/29/2023] [Accepted: 01/18/2024] [Indexed: 02/24/2024] Open
Abstract
Transcription enables the production of RNA from a DNA template. Due to the highly dynamic nature of transcription, live-cell imaging methods play a crucial role in measuring the kinetics of this process. For instance, transcriptional bursts have been visualized using fluorescent phage-coat proteins that associate tightly with messenger RNA (mRNA) stem loops formed on nascent transcripts. To convert the signal emanating from a transcription site into meaningful estimates of transcription dynamics, the influence of various parameters on the measured signal must be evaluated. Here, the effect of gene length on the intensity of the transcription site focus was analyzed. Intuitively, a longer gene can support a larger number of transcribing polymerases, thus leading to an increase in the measured signal. However, measurements of transcription induced by hyper-osmotic stress responsive promoters display independence from gene length. A mathematical model of the stress-induced transcription process suggests that the formation of gene loops that favor the recycling of polymerase from the terminator to the promoter can explain the observed behavior. One experimentally validated prediction from this model is that the amount of mRNA produced from a short gene should be higher than for a long one as the density of active polymerase on the short gene will be increased by polymerase recycling. Our data suggest that this recycling contributes significantly to the expression output from a gene and that polymerase recycling is modulated by the promoter identity and the cellular state.
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Affiliation(s)
- Olivia Kindongo
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Guillaume Lieb
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Benjamin Skaggs
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Yves Dusserre
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Vincent Vincenzetti
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Serge Pelet
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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12
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Pomp W, Meeussen JVW, Lenstra TL. Transcription factor exchange enables prolonged transcriptional bursts. Mol Cell 2024; 84:1036-1048.e9. [PMID: 38377994 PMCID: PMC10962226 DOI: 10.1016/j.molcel.2024.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 11/27/2023] [Accepted: 01/24/2024] [Indexed: 02/22/2024]
Abstract
Single-molecule imaging inside living cells has revealed that transcription factors (TFs) bind to DNA transiently, but a long-standing question is how this transient binding is related to transcription activation. Here, we devised a microscopy method to simultaneously measure transient TF binding at a single locus and the effect of these binding events on transcription. We show that DNA binding of the yeast TF Gal4 activates transcription of a target gene within a few seconds, with at least ∼20% efficiency and with a high initiation rate of ∼1 RNA/s. Gal4 DNA dissociation decreases transcription rapidly. Moreover, at a gene with multiple binding sites, individual Gal4 molecules only rarely stay bound throughout the entire burst but instead frequently exchange during a burst to increase the transcriptional burst duration. Our results suggest a mechanism for enhancer regulation in more complex eukaryotes, where TF cooperativity and exchange enable robust and responsive transcription regulation.
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Affiliation(s)
- Wim Pomp
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Joseph V W Meeussen
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands.
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13
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Janissen R, Barth R, Polinder M, van der Torre J, Dekker C. Single-molecule visualization of twin-supercoiled domains generated during transcription. Nucleic Acids Res 2024; 52:1677-1687. [PMID: 38084930 PMCID: PMC10899792 DOI: 10.1093/nar/gkad1181] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/13/2023] [Accepted: 11/30/2023] [Indexed: 02/29/2024] Open
Abstract
Transcription-coupled supercoiling of DNA is a key factor in chromosome compaction and the regulation of genetic processes in all domains of life. It has become common knowledge that, during transcription, the DNA-dependent RNA polymerase (RNAP) induces positive supercoiling ahead of it (downstream) and negative supercoils in its wake (upstream), as rotation of RNAP around the DNA axis upon tracking its helical groove gets constrained due to drag on its RNA transcript. Here, we experimentally validate this so-called twin-supercoiled-domain model with in vitro real-time visualization at the single-molecule scale. Upon binding to the promoter site on a supercoiled DNA molecule, RNAP merges all DNA supercoils into one large pinned plectoneme with RNAP residing at its apex. Transcription by RNAP in real time demonstrates that up- and downstream supercoils are generated simultaneously and in equal portions, in agreement with the twin-supercoiled-domain model. Experiments carried out in the presence of RNases A and H, revealed that an additional viscous drag of the RNA transcript is not necessary for the RNAP to induce supercoils. The latter results contrast the current consensus and simulations on the origin of the twin-supercoiled domains, pointing at an additional mechanistic cause underlying supercoil generation by RNAP in transcription.
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Affiliation(s)
- Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Minco Polinder
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
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14
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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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