1
|
Yue XJ, Wang JR, Zhao JN, Pan Z, Li YZ. Determination of the chromosomal position effects for plug-and-play application in the Myxococcus xanthus chassis cells. Synth Syst Biotechnol 2024; 9:540-548. [PMID: 38680947 PMCID: PMC11046052 DOI: 10.1016/j.synbio.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/30/2024] [Accepted: 04/08/2024] [Indexed: 05/01/2024] Open
Abstract
The chromosomal position effect can significantly affect the transgene expression, which may provide an efficient strategy for the inauguration of alien genes in new hosts, but has been less explored rationally. The bacterium Myxococcus xanthus harbors a large circular high-GC genome, and the position effect in this chassis may result in a thousand-fold expression variation of alien natural products. In this study, we conducted transposon insertion at TA sites on the M. xanthus genome, and used enrichment and dilution indexes to respectively appraise high and low expression potentials of alien genes at insertion sites. The enrichment sites are characteristically distributed along the genome, and the dilution sites are overlapped well with the horizontal transfer genes. We experimentally demonstrated the enrichment sites as high expression integration sites (HEISs), and the dilution sites unsuitable for gene integration expression. This work highlights that HEISs are the plug-and-play sites for efficient expression of integrated genes.
Collapse
Affiliation(s)
- Xin-jing Yue
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Jia-rui Wang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Jun-ning Zhao
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Zhuo Pan
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| | - Yue-zhong Li
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, PR China
| |
Collapse
|
2
|
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] [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.
Collapse
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.
| |
Collapse
|
3
|
Prevo B, Earnshaw WC. DNA packaging by molecular motors: from bacteriophage to human chromosomes. Nat Rev Genet 2024:10.1038/s41576-024-00740-y. [PMID: 38886215 DOI: 10.1038/s41576-024-00740-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2024] [Indexed: 06/20/2024]
Abstract
Dense packaging of genomic DNA is crucial for organismal survival, as DNA length always far exceeds the dimensions of the cells that contain it. Organisms, therefore, use sophisticated machineries to package their genomes. These systems range across kingdoms from a single ultra-powerful rotary motor that spools the DNA into a bacteriophage head, to hundreds of thousands of relatively weak molecular motors that coordinate the compaction of mitotic chromosomes in eukaryotic cells. Recent technological advances, such as DNA proximity-based sequencing approaches, polymer modelling and in vitro reconstitution of DNA loop extrusion, have shed light on the biological mechanisms driving DNA organization in different systems. Here, we discuss DNA packaging in bacteriophage, bacteria and eukaryotic cells, which, despite their extreme variation in size, structure and genomic content, all rely on the action of molecular motors to package their genomes.
Collapse
Affiliation(s)
- Bram Prevo
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK.
| | - William C Earnshaw
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK.
| |
Collapse
|
4
|
Hong Y, Ye F, Qian J, Gao X, Inman JT, Wang MD. Optical Torque Calculations and Measurements for DNA Torsional Studies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596477. [PMID: 38853956 PMCID: PMC11160753 DOI: 10.1101/2024.05.29.596477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The angular optical trap (AOT) is a powerful instrument for measuring the torsional and rotational properties of a biological molecule. Thus far, AOT studies of DNA torsional mechanics have been carried out using a high numerical aperture oil-immersion objective, which permits strong trapping, but inevitably introduces spherical aberrations due to the glass-aqueous interface. However, the impact of these aberrations on torque measurements is not fully understood experimentally, partly due to a lack of theoretical guidance. Here, we present a numerical platform based on the finite element method to calculate forces and torques on a trapped quartz cylinder. We have also developed a new experimental method to accurately determine the shift in the trapping position due to the spherical aberrations by using a DNA molecule as a distance ruler. We found that the calculated and measured focal shift ratios are in good agreement. We further determined how the angular trap stiffness depends on the trap height and the cylinder displacement from the trap center and found full agreement between predictions and measurements. As further verification of the methodology, we showed that DNA torsional properties, which are intrinsic to DNA, could be determined robustly under different trap heights and cylinder displacements. Thus, this work has laid both a theoretical and experimental framework that can be readily extended to investigate the trapping forces and torques exerted on particles with arbitrary shapes and optical properties. SIGNIFICANCE We developed a simulation platform based on the finite element method for force and torque calculation for particles in an angular optical trap (AOT), with considerations of tightly focused Gaussian beam, spherical aberrations, and optically anisotropic particles. Experimental measurements of focal shift ratio, force, and torque under multiple conditions were in good agreement with predictions from the simulations. We also demonstrated that intrinsic DNA torsional properties can be robustly measured under different AOT measurement conditions, strongly validating our simulations and calibrations. Our platform can facilitate trapping particle design for single-molecule assays using the AOT.
Collapse
|
5
|
Bairamukov VY, Kovalev RA, Ankudinov AV, Pantina RA, Fedorova ND, Bukatin AS, Grigoriev SV, Varfolomeeva EY. Alterations in the chromatin packaging, driven by transcriptional activity, revealed by AFM. Biochim Biophys Acta Gen Subj 2024; 1868:130568. [PMID: 38242181 DOI: 10.1016/j.bbagen.2024.130568] [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: 06/15/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
BACKGROUND The gene expression differs in the nuclei of normal and malignant mammalian cells, and transcription is a critical initial step, which defines the difference. The mechanical properties of transcriptionally active chromatin are still poorly understood. Recently we have probed transcriptionally active chromatin of the nuclei subjected to mechanical stress, by Atomic Force Microscopy (AFM) [1]. Nonetheless, a systematic study of the phenomenon is needed. METHODS Nuclei were deformed and studied by AFM. Non-deformed nuclei were studied by fluorescence confocal microscopy. Their transcriptional activity was studied by RNA electrophoresis. RESULTS The malignant nuclei under the study were stable to deformation and assembled of 100-300 nm beads-like units, while normal cell nuclei were prone to deformation. The difference in stability to deformation of the nuclei correlated with DNA supercoiling, and transcription-depended units were responsive to supercoils breakage. The inhibitors of the topoisomerases I and II disrupted supercoiling and made the malignant nucleus prone to deformation. Cell nuclei treatment with histone deacetylase inhibitors (HDACIs) preserved the mechanical stability of deformed malignant nuclei and, at the same time, made it possible to observe chromatin decondensation up to 20-60 nm units. The AFM results were supplemented with confocal microscopy and RNA electrophoresis data. CONCLUSIONS Self-assembly of transcriptionally active chromatin and its decondensation, driven by DNA supercoiling-dependent rigidity, was visualized by AFM in the mechanically deformed nuclei. GENERAL SIGNIFICANCE We demonstrated that supercoiled DNA defines the transcription mechanics, and hypothesized the nuclear mechanics in vivo should depend on the chromatin architecture.
Collapse
Affiliation(s)
- V Yu Bairamukov
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia.
| | - R A Kovalev
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - A V Ankudinov
- The Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 26, Politekhnicheskaya, 194021 Saint Petersburg, Russia
| | - R A Pantina
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - N D Fedorova
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - A S Bukatin
- Alferov Saint Petersburg National Research Academic University of the Russian Academy of Sciences, 8/3, Khlopina St., 194021 Saint Petersburg, Russia
| | - S V Grigoriev
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| | - E Yu Varfolomeeva
- Petersburg Nuclear Physics Institute Named by B.P. Konstantinov of NRC "Kurchatov Institute", 1, Orlova Roshcha, 188300 Gatchina, Russia
| |
Collapse
|
6
|
Figueroa-Bossi N, Fernández-Fernández R, Kerboriou P, Bouloc P, Casadesús J, Sánchez-Romero MA, Bossi L. Transcription-driven DNA supercoiling counteracts H-NS-mediated gene silencing in bacterial chromatin. Nat Commun 2024; 15:2787. [PMID: 38555352 PMCID: PMC10981669 DOI: 10.1038/s41467-024-47114-w] [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: 10/09/2023] [Accepted: 03/19/2024] [Indexed: 04/02/2024] Open
Abstract
In all living cells, genomic DNA is compacted through interactions with dedicated proteins and/or the formation of plectonemic coils. In bacteria, DNA compaction is achieved dynamically, coordinated with dense and constantly changing transcriptional activity. H-NS, a major bacterial nucleoid structuring protein, is of special interest due to its interplay with RNA polymerase. H-NS:DNA nucleoprotein filaments inhibit transcription initiation by RNA polymerase. However, the discovery that genes silenced by H-NS can be activated by transcription originating from neighboring regions has suggested that elongating RNA polymerases can disassemble H-NS:DNA filaments. In this study, we present evidence that transcription-induced counter-silencing does not require transcription to reach the silenced gene; rather, it exerts its effect at a distance. Counter-silencing is suppressed by introducing a DNA gyrase binding site within the intervening segment, suggesting that the long-range effect results from transcription-driven positive DNA supercoils diffusing toward the silenced gene. We propose a model wherein H-NS:DNA complexes form in vivo on negatively supercoiled DNA, with H-NS bridging the two arms of the plectoneme. Rotational diffusion of positive supercoils generated by neighboring transcription will cause the H-NS-bound negatively-supercoiled plectoneme to "unroll" disrupting the H-NS bridges and releasing H-NS.
Collapse
Affiliation(s)
- Nara Figueroa-Bossi
- Université Paris-Saclay, CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Gif-sur-Yvette, France
| | - Rocío Fernández-Fernández
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain
| | - Patricia Kerboriou
- Université Paris-Saclay, CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Gif-sur-Yvette, France
| | - Philippe Bouloc
- Université Paris-Saclay, CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Gif-sur-Yvette, France
| | - Josep Casadesús
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | | | - Lionello Bossi
- Université Paris-Saclay, CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Gif-sur-Yvette, France.
| |
Collapse
|
7
|
Hidmi O, Oster S, Monin J, Aqeilan RI. TOP1 and R-loops facilitate transcriptional DSBs at hypertranscribed cancer driver genes. iScience 2024; 27:109082. [PMID: 38375218 PMCID: PMC10875566 DOI: 10.1016/j.isci.2024.109082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/26/2023] [Accepted: 01/28/2024] [Indexed: 02/21/2024] Open
Abstract
DNA double-stranded breaks (DSBs) pose a significant threat to genomic integrity, and their generation during essential cellular processes like transcription remains poorly understood. In this study, we employ several techniques to map DSBs, R-loops, and topoisomerase 1 cleavage complex (TOP1cc) to comprehensively investigate the interplay between transcription, DSBs, topoisomerase 1 (TOP1), and R-loops. Our findings reveal the presence of DSBs at highly expressed genes enriched with TOP1 and R-loops. Remarkably, transcription-associated DSBs at these loci are significantly reduced upon depletion of R-loops and TOP1, uncovering the pivotal roles of TOP1 and R-loops in transcriptional DSB formation. By elucidating the intricate interplay between TOP1cc trapping, R-loops, and DSBs, our study provides insights into the mechanisms underlying transcription-associated genomic instability. Moreover, we establish a link between transcriptional DSBs and early molecular changes driving cancer development, highlighting the distinct etiology and molecular characteristics of driver mutations compared to passenger mutations.
Collapse
Affiliation(s)
- Osama Hidmi
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sara Oster
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jonathan Monin
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rami I. Aqeilan
- The Concern Foundation Laboratories, The Lautenberg Center for Immunology and Cancer Research, Department of Immunology and Cancer Research-IMRIC, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- Cyprus Cancer Research Institute (CCRI), Nicosia, Cyprus
| |
Collapse
|
8
|
Gilhooly NS, Kowalczykowski SC. Specific anchoring of large topologically closed DNA for single-molecule protein:DNA interactions. BIOPHYSICAL REPORTS 2024; 4:100144. [PMID: 38390466 PMCID: PMC10881311 DOI: 10.1016/j.bpr.2024.100144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 01/22/2024] [Indexed: 02/24/2024]
Abstract
Single-molecule and bulk biophysical approaches to study protein-DNA interactions on surface-immobilized nucleic acid templates typically rely on modifying the ends of linear DNA molecules to enable surface-DNA attachments. Unless both strands are constrained, this results in topologically free DNA molecules and the inability to observe supercoiling-dependent biological processes or requires additional means to micromanipulate the free DNA end to impose rotational constraints or induce supercoiling. We developed a method using RecA protein to induce the formation of a circularized compliment-stabilized D-loop. The resulting joint molecule is topologically closed, surface anchorable, and stable under microfluidic flow. Importantly, the method obviates the need for subsequent manipulation of surface-tethered DNA; tethered molecules remain supercoiled and retain accessibility to DNA-binding proteins. This approach adds to the toolkit for those studying processes on DNA that require supercoiled DNA templates or topologically constrained systems.
Collapse
Affiliation(s)
- Neville S Gilhooly
- Department of Microbiology and Molecular Genetics and Department of Molecular and Cellular Biology, University of California, Davis, Davis, California
| | - Stephen C Kowalczykowski
- Department of Microbiology and Molecular Genetics and Department of Molecular and Cellular Biology, University of California, Davis, Davis, California
| |
Collapse
|
9
|
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: 1] [Impact Index Per Article: 1.0] [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.
Collapse
Affiliation(s)
- Richard Janissen
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Roman Barth
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Minco Polinder
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Jaco van der Torre
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, South-Holland 2629HZ, The Netherlands
| |
Collapse
|
10
|
Tan BG, Gustafsson CM, Falkenberg M. Mechanisms and regulation of human mitochondrial transcription. Nat Rev Mol Cell Biol 2024; 25:119-132. [PMID: 37783784 DOI: 10.1038/s41580-023-00661-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2023] [Indexed: 10/04/2023]
Abstract
The expression of mitochondrial genes is regulated in response to the metabolic needs of different cell types, but the basic mechanisms underlying this process are still poorly understood. In this Review, we describe how different layers of regulation cooperate to fine tune initiation of both mitochondrial DNA (mtDNA) transcription and replication in human cells. We discuss our current understanding of the molecular mechanisms that drive and regulate transcription initiation from mtDNA promoters, and how the packaging of mtDNA into nucleoids can control the number of mtDNA molecules available for both transcription and replication. Indeed, a unique aspect of the mitochondrial transcription machinery is that it is coupled to mtDNA replication, such that mitochondrial RNA polymerase is additionally required for primer synthesis at mtDNA origins of replication. We discuss how the choice between replication-primer formation and genome-length RNA synthesis is controlled at the main origin of replication (OriH) and how the recent discovery of an additional mitochondrial promoter (LSP2) in humans may change this long-standing model.
Collapse
Affiliation(s)
- Benedict G Tan
- Institute for Mitochondrial Diseases and Ageing, Faculty of Medicine and University Hospital Cologne, Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
| |
Collapse
|
11
|
Wang L. RNA polymerase collisions and their role in transcription. Transcription 2024; 15:38-47. [PMID: 38357902 DOI: 10.1080/21541264.2024.2316972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/06/2024] [Indexed: 02/16/2024] Open
Abstract
RNA polymerases are the central enzymes of gene expression and function frequently in either a head-on or co-directional manner on the busy DNA track. Whether and how these collisions between RNA polymerases contribute to transcriptional regulation is mysterious. Increasing evidence from biochemical and single-molecule studies suggests that RNA polymerase collisions function as an important regulator to fine-tune transcription, rather than creating deleterious "traffic jams". This review summarizes the recent progress on elucidating the consequences of RNA polymerase collisions during transcription and highlights the significance of cooperation and coordination between RNA polymerases.
Collapse
Affiliation(s)
- Ling Wang
- Department of Chemical Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| |
Collapse
|
12
|
Greiss F, Lardon N, Schütz L, Barak Y, Daube SS, Weinhold E, Noireaux V, Bar-Ziv R. A genetic circuit on a single DNA molecule as an autonomous dissipative nanodevice. Nat Commun 2024; 15:883. [PMID: 38287055 PMCID: PMC10825189 DOI: 10.1038/s41467-024-45186-2] [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: 11/03/2023] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
Realizing genetic circuits on single DNA molecules as self-encoded dissipative nanodevices is a major step toward miniaturization of autonomous biological systems. A circuit operating on a single DNA implies that genetically encoded proteins localize during coupled transcription-translation to DNA, but a single-molecule measurement demonstrating this has remained a challenge. Here, we use a genetically encoded fluorescent reporter system with improved temporal resolution and observe the synthesis of individual proteins tethered to a DNA molecule by transient complexes of RNA polymerase, messenger RNA, and ribosome. Against expectations in dilute cell-free conditions where equilibrium considerations favor dispersion, these nascent proteins linger long enough to regulate cascaded reactions on the same DNA. We rationally design a pulsatile genetic circuit by encoding an activator and repressor in feedback on the same DNA molecule. Driven by the local synthesis of only several proteins per hour and gene, the circuit dynamics exhibit enhanced variability between individual DNA molecules, and fluctuations with a broad power spectrum. Our results demonstrate that co-expressional localization, as a nonequilibrium process, facilitates single-DNA genetic circuits as dissipative nanodevices, with implications for nanobiotechnology applications and artificial cell design.
Collapse
Affiliation(s)
- Ferdinand Greiss
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Nicolas Lardon
- Department of Chemical Biology, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
| | - Leonie Schütz
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Yoav Barak
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Shirley S Daube
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Roy Bar-Ziv
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| |
Collapse
|
13
|
Fu Z, Guo MS, Zhou W, Xiao J. Differential roles of positive and negative supercoiling in organizing the E. coli genome. Nucleic Acids Res 2024; 52:724-737. [PMID: 38050973 PMCID: PMC10810199 DOI: 10.1093/nar/gkad1139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/01/2023] [Accepted: 11/21/2023] [Indexed: 12/07/2023] Open
Abstract
This study aims to explore whether and how positive and negative supercoiling contribute to the three-dimensional (3D) organization of the bacterial genome. We used recently published Escherichia coli GapR ChIP-seq and TopoI ChIP-seq (also called EcTopoI-seq) data, which marks positive and negative supercoiling sites, respectively, to study how supercoiling correlates with the spatial contact maps obtained from chromosome conformation capture sequencing (Hi-C and 5C). We find that supercoiled chromosomal loci have overall higher Hi-C contact frequencies than sites that are not supercoiled. Surprisingly, positive supercoiling corresponds to higher spatial contact than negative supercoiling. Additionally, positive, but not negative, supercoiling could be identified from Hi-C data with high accuracy. We further find that the majority of positive and negative supercoils coincide with highly active transcription units, with a minor group likely associated with replication and other genomic processes. Our results show that both positive and negative supercoiling enhance spatial contact, with positive supercoiling playing a larger role in bringing genomic loci closer in space. Based on our results, we propose new physical models of how the E. coli chromosome is organized by positive and negative supercoils.
Collapse
Affiliation(s)
- Ziqi Fu
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Monica S Guo
- Department of Microbiology, University of Washington, Seattle, WA 98198, USA
| | - Weiqiang Zhou
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| |
Collapse
|
14
|
Bunch H, Kim D, Naganuma M, Nakagawa R, Cong A, Jeong J, Ehara H, Vu H, Chang JH, Schellenberg MJ, Sekine SI. ERK2-topoisomerase II regulatory axis is important for gene activation in immediate early genes. Nat Commun 2023; 14:8341. [PMID: 38097570 PMCID: PMC10721843 DOI: 10.1038/s41467-023-44089-y] [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: 09/14/2022] [Accepted: 11/29/2023] [Indexed: 12/17/2023] Open
Abstract
The function of the mitogen-activated protein kinase signaling pathway is required for the activation of immediate early genes (IEGs), including EGR1 and FOS, for cell growth and proliferation. Recent studies have identified topoisomerase II (TOP2) as one of the important regulators of the transcriptional activation of IEGs. However, the mechanism underlying transcriptional regulation involving TOP2 in IEG activation has remained unknown. Here, we demonstrate that ERK2, but not ERK1, is important for IEG transcriptional activation and report a critical ELK1 binding sequence for ERK2 function at the EGR1 gene. Our data indicate that both ERK1 and ERK2 extensively phosphorylate the C-terminal domain of TOP2B at mutual and distinctive residues. Although both ERK1 and ERK2 enhance the catalytic rate of TOP2B required to relax positive DNA supercoiling, ERK2 delays TOP2B catalysis of negative DNA supercoiling. In addition, ERK1 may relax DNA supercoiling by itself. ERK2 catalytic inhibition or knock-down interferes with transcription and deregulates TOP2B in IEGs. Furthermore, we present the first cryo-EM structure of the human cell-purified TOP2B and etoposide together with the EGR1 transcriptional start site (-30 to +20) that has the strongest affinity to TOP2B within -423 to +332. The structure shows TOP2B-mediated breakage and dramatic bending of the DNA. Transcription is activated by etoposide, while it is inhibited by ICRF193 at EGR1 and FOS, suggesting that TOP2B-mediated DNA break to favor transcriptional activation. Taken together, this study suggests that activated ERK2 phosphorylates TOP2B to regulate TOP2-DNA interactions and favor transcriptional activation in IEGs. We propose that TOP2B association, catalysis, and dissociation on its substrate DNA are important processes for regulating transcription and that ERK2-mediated TOP2B phosphorylation may be key for the catalysis and dissociation steps.
Collapse
Affiliation(s)
- Heeyoun Bunch
- Department of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea.
- School of Applied Biosciences, College of Agriculture & Life Sciences, Kyungpook National University, Daegu, 41566, Republic of Korea.
| | - Deukyeong Kim
- School of Applied Biosciences, College of Agriculture & Life Sciences, Kyungpook National University, Daegu, 41566, Republic of Korea
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Masahiro Naganuma
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Reiko Nakagawa
- RIKEN BDR Laboratory for Phyloinformatics, Hyogo, 650-0047, Japan
| | - Anh Cong
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jaehyeon Jeong
- Department of Applied Biosciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Haruhiko Ehara
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Hongha Vu
- Department of Biology Education, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Jeong Ho Chang
- Department of Biology Education, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Matthew J Schellenberg
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Shun-Ichi Sekine
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| |
Collapse
|
15
|
Gómez-González B, Aguilera A. Break-induced RNA-DNA hybrids (BIRDHs) in homologous recombination: friend or foe? EMBO Rep 2023; 24:e57801. [PMID: 37818834 DOI: 10.15252/embr.202357801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/29/2023] [Accepted: 09/26/2023] [Indexed: 10/13/2023] Open
Abstract
Double-strand breaks (DSBs) are the most harmful DNA lesions, with a strong impact on cell proliferation and genome integrity. Depending on cell cycle stage, DSBs are preferentially repaired by non-homologous end joining or homologous recombination (HR). In recent years, numerous reports have revealed that DSBs enhance DNA-RNA hybrid formation around the break site. We call these hybrids "break-induced RNA-DNA hybrids" (BIRDHs) to differentiate them from sporadic R-loops consisting of DNA-RNA hybrids and a displaced single-strand DNA occurring co-transcriptionally in intact DNA. Here, we review and discuss the most relevant data about BIRDHs, with a focus on two main questions raised: (i) whether BIRDHs form by de novo transcription after a DSB or by a pre-existing nascent RNA in DNA regions undergoing transcription and (ii) whether they have a positive role in HR or are just obstacles to HR accidentally generated as an intrinsic risk of transcription. We aim to provide a comprehensive view of the exciting and yet unresolved questions about the source and impact of BIRDHs in the cell.
Collapse
Affiliation(s)
- Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC, Seville, Spain
| |
Collapse
|
16
|
Dubey S, Maurya RK, Shree S, Kumar S, Jahan F, Krishnan MY, Ramachandran R. Mycobacterium tuberculosis Rv2324 is a multifunctional feast/famine regulatory protein involved in growth, DNA replication and damage control. Int J Biol Macromol 2023; 252:126459. [PMID: 37634786 DOI: 10.1016/j.ijbiomac.2023.126459] [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: 02/02/2023] [Revised: 06/20/2023] [Accepted: 08/20/2023] [Indexed: 08/29/2023]
Abstract
Feast/famine regulatory proteins (FFRPs) are multifunctional regulators. We show that Mtb Rv2324 is important for growth, survival, and countering DNA damage in Mycobacterium tuberculosis (Mtb). DNA-relaxation activity against linear and supercoiled substrates suggest its involvement in transcription activation, while its high affinity for recombination, replication and repair substrates suggest a role there too. Small-Angle-X-ray scattering supports the adoption of an 'open' quaternary association in response to amino-acid binding. Size-exclusion-chromatography and glutaraldehyde cross-linking identify the adoption of diverse oligomers modulated by amino-acid binding, and DNA interactions. We tested G52A, G101T and D104A mutants which correspond to highly conserved residues, distal to the DNA-binding site, and are important for amino acids binding. G101T exhibits increased DNA affinity, while G52A and D104A exhibit weak DNA-binding thereby suggesting that they mediate effector-binding, and DNA binding activities. Gain and loss-of-function studies show that Rv2324 overexpression promotes growth-rate, while its knock-down leads to retarded growth. Rv2324 down-regulation lowers Mtb survival inside resting and IFN-ϒ-activated macrophages. Rv2324 protects the pathogen from DNA damage, as evidenced by the reduction in the knockdown strain's survival following treatment with H2O2 and UV light. Overall, we show that Rv2324 plays a crucial role in regulating survival and growth of Mtb.
Collapse
Affiliation(s)
- Shikha Dubey
- Biochemistry and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Uttar Pradesh 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Rahul Kumar Maurya
- Molecular Microbiology and Immunology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Uttar Pradesh 226031, India
| | - Sonal Shree
- Biochemistry and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Uttar Pradesh 226031, India; Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA
| | - Sanjay Kumar
- Biochemistry and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Uttar Pradesh 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Farheen Jahan
- Biochemistry and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Uttar Pradesh 226031, India
| | - Manju Yasoda Krishnan
- Molecular Microbiology and Immunology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Uttar Pradesh 226031, India
| | - Ravishankar Ramachandran
- Biochemistry and Structural Biology Division, CSIR-Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Uttar Pradesh 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
| |
Collapse
|
17
|
Boulas I, Bruno L, Rimsky S, Espeli O, Junier I, Rivoire O. Assessing in vivo the impact of gene context on transcription through DNA supercoiling. Nucleic Acids Res 2023; 51:9509-9521. [PMID: 37667073 PMCID: PMC10570042 DOI: 10.1093/nar/gkad688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 07/24/2023] [Accepted: 08/09/2023] [Indexed: 09/06/2023] Open
Abstract
Gene context can have significant impact on gene expression but is currently not integrated in quantitative models of gene regulation despite known biophysical principles and quantitative in vitro measurements. Conceptually, the simplest gene context consists of a single gene framed by two topological barriers, known as the twin transcriptional-loop model, which illustrates the interplay between transcription and DNA supercoiling. In vivo, DNA supercoiling is additionally modulated by topoisomerases, whose modus operandi remains to be quantified. Here, we bridge the gap between theory and in vivo properties by realizing in Escherichia coli the twin transcriptional-loop model and by measuring how gene expression varies with promoters and distances to the topological barriers. We find that gene expression depends on the distance to the upstream barrier but not to the downstream barrier, with a promoter-dependent intensity. We rationalize these findings with a first-principle biophysical model of DNA transcription. Our results are explained if TopoI and gyrase both act specifically, respectively upstream and downstream of the gene, with antagonistic effects of TopoI, which can repress initiation while facilitating elongation. Altogether, our work sets the foundations for a systematic and quantitative description of the impact of gene context on gene regulation.
Collapse
Affiliation(s)
- Ihab Boulas
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Lisa Bruno
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Sylvie Rimsky
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Olivier Espeli
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Ivan Junier
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
| | - Olivier Rivoire
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Gulliver, ESPCI, CNRS, Université PSL, Paris, France
| |
Collapse
|
18
|
Cowell IG, Casement JW, Austin CA. To Break or Not to Break: The Role of TOP2B in Transcription. Int J Mol Sci 2023; 24:14806. [PMID: 37834253 PMCID: PMC10573011 DOI: 10.3390/ijms241914806] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023] Open
Abstract
Transcription and its regulation pose challenges related to DNA torsion and supercoiling of the DNA template. RNA polymerase tracking the helical groove of the DNA introduces positive helical torsion and supercoiling upstream and negative torsion and supercoiling behind its direction of travel. This can inhibit transcriptional elongation and other processes essential to transcription. In addition, chromatin remodeling associated with gene activation can generate or be hindered by excess DNA torsional stress in gene regulatory regions. These topological challenges are solved by DNA topoisomerases via a strand-passage reaction which involves transiently breaking and re-joining of one (type I topoisomerases) or both (type II topoisomerases) strands of the phosphodiester backbone. This review will focus on one of the two mammalian type II DNA topoisomerase enzymes, DNA topoisomerase II beta (TOP2B), that have been implicated in correct execution of developmental transcriptional programs and in signal-induced transcription, including transcriptional activation by nuclear hormone ligands. Surprisingly, several lines of evidence indicate that TOP2B-mediated protein-free DNA double-strand breaks are involved in signal-induced transcription. We discuss the possible significance and origins of these DSBs along with a network of protein interaction data supporting a variety of roles for TOP2B in transcriptional regulation.
Collapse
Affiliation(s)
- Ian G. Cowell
- Biosciences Institute, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - John W. Casement
- Bioinformatics Support Unit, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Caroline A. Austin
- Biosciences Institute, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| |
Collapse
|
19
|
Biswas P, Sengupta S, Nagaraja V. Evolution of YacG to safeguard DNA gyrase from external perturbation. Res Microbiol 2023; 174:104093. [PMID: 37343614 DOI: 10.1016/j.resmic.2023.104093] [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: 03/20/2023] [Revised: 06/10/2023] [Accepted: 06/14/2023] [Indexed: 06/23/2023]
Abstract
Cells have evolved strategies to safeguard their genome integrity. We describe a mechanism to counter double strand breaks in the chromosome that involves the protection of an essential housekeeping enzyme from external agents. YacG is a DNA gyrase inhibitory protein from Escherichia coli that protects the bacterium from the cytotoxic effects of catalytic inhibitors as well as cleavage-complex stabilizers of DNA gyrase. By virtue of blocking the primary DNA binding site of the enzyme, YacG prevents the accumulation of double strand breaks induced by gyrase poisons. It also enables the bacterium to resist the growth-inhibitory property of novobiocin. Gyrase poison-induced oxidative stress upregulates YacG production, probably as a cellular response to counter DNA damage. YacG-mediated protection of the genome is specific for gyrase targeting agents as the protection is not observed from the action of general DNA damaging agents. YacG also intensifies the transcription stress induced by rifampicin substantiating the importance of gyrase activity during transcription. Although essential for bacterial survival, DNA gyrase often gets entrapped by external inhibitors and poisons, resulting in cell death. The existence of YacG to specifically protect an essential housekeeping enzyme might be a strategy adopted by bacteria for competitive fitness advantage.
Collapse
Affiliation(s)
- Priti Biswas
- Department of Life Sciences, Presidency University Kolkata, 86/1 College Street, Kolkata-700073, India.
| | - Sugopa Sengupta
- Department of Life Sciences, Presidency University Kolkata, 86/1 College Street, Kolkata-700073, India.
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India; Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore-560064, India.
| |
Collapse
|
20
|
Einig E, Jin C, Andrioletti V, Macek B, Popov N. RNAPII-dependent ATM signaling at collisions with replication forks. Nat Commun 2023; 14:5147. [PMID: 37620345 PMCID: PMC10449895 DOI: 10.1038/s41467-023-40924-4] [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: 01/13/2023] [Accepted: 08/16/2023] [Indexed: 08/26/2023] Open
Abstract
Deregulation of RNA Polymerase II (RNAPII) by oncogenic signaling leads to collisions of RNAPII with DNA synthesis machinery (transcription-replication conflicts, TRCs). TRCs can result in DNA damage and are thought to underlie genomic instability in tumor cells. Here we provide evidence that elongating RNAPII nucleates activation of the ATM kinase at TRCs to stimulate DNA repair. We show the ATPase WRNIP1 associates with RNAPII and limits ATM activation during unperturbed cell cycle. WRNIP1 binding to elongating RNAPII requires catalytic activity of the ubiquitin ligase HUWE1. Mutation of HUWE1 induces TRCs, promotes WRNIP1 dissociation from RNAPII and binding to the replisome, stimulating ATM recruitment and activation at RNAPII. TRCs and translocation of WRNIP1 are rapidly induced in response to hydroxyurea treatment to activate ATM and facilitate subsequent DNA repair. We propose that TRCs can provide a controlled mechanism for stalling of replication forks and ATM activation, instrumental in cellular response to replicative stress.
Collapse
Affiliation(s)
- Elias Einig
- Department of Medical Oncology and Pulmonology, University Hospital Tübingen, Otfried-Mueller-Str 14, 72076, Tübingen, Germany
| | - Chao Jin
- Department of Medical Oncology and Pulmonology, University Hospital Tübingen, Otfried-Mueller-Str 14, 72076, Tübingen, Germany
| | - Valentina Andrioletti
- Department of Medical Oncology and Pulmonology, University Hospital Tübingen, Otfried-Mueller-Str 14, 72076, Tübingen, Germany
- enGenome S.R.L., Via Fratelli Cuzio 42, 27100, Pavia, Italy
| | - Boris Macek
- Interfaculty Institute of Cell Biology, Eberhard Karls University of Tübingen, Auf d. Morgenstelle 15, 72076, Tübingen, Germany
| | - Nikita Popov
- Department of Medical Oncology and Pulmonology, University Hospital Tübingen, Otfried-Mueller-Str 14, 72076, Tübingen, Germany.
| |
Collapse
|
21
|
Lininger A, Palermo G, Guglielmelli A, Nicoletta G, Goel M, Hinczewski M, Strangi G. Chirality in Light-Matter Interaction. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2107325. [PMID: 35532188 DOI: 10.1002/adma.202107325] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 04/07/2022] [Indexed: 06/14/2023]
Abstract
The scientific effort to control the interaction between light and matter has grown exponentially in the last 2 decades. This growth has been aided by the development of scientific and technological tools enabling the manipulation of light at deeply sub-wavelength scales, unlocking a large variety of novel phenomena spanning traditionally distant research areas. Here, the role of chirality in light-matter interactions is reviewed by providing a broad overview of its properties, materials, and applications. A perspective on future developments is highlighted, including the growing role of machine learning in designing advanced chiroptical materials to enhance and control light-matter interactions across several scales.
Collapse
Affiliation(s)
- Andrew Lininger
- Department of Physics, Case Western Reserve University, 2076 Adelbert Rd, Cleveland, OH, 44106, USA
| | - Giovanna Palermo
- Department of Physics, NLHT-Lab, University of Calabria and CNR-NANOTEC Istituto di Nanotecnologia, Rende, 87036, Italy
| | - Alexa Guglielmelli
- Department of Physics, NLHT-Lab, University of Calabria and CNR-NANOTEC Istituto di Nanotecnologia, Rende, 87036, Italy
| | - Giuseppe Nicoletta
- Department of Physics, NLHT-Lab, University of Calabria and CNR-NANOTEC Istituto di Nanotecnologia, Rende, 87036, Italy
| | - Madhav Goel
- Department of Physics, Case Western Reserve University, 2076 Adelbert Rd, Cleveland, OH, 44106, USA
| | - Michael Hinczewski
- Department of Physics, Case Western Reserve University, 2076 Adelbert Rd, Cleveland, OH, 44106, USA
| | - Giuseppe Strangi
- Department of Physics, Case Western Reserve University, 2076 Adelbert Rd, Cleveland, OH, 44106, USA
- Department of Physics, NLHT-Lab, University of Calabria and CNR-NANOTEC Istituto di Nanotecnologia, Rende, 87036, Italy
| |
Collapse
|
22
|
Choudhary R, Niska-Blakie J, Adhil M, Liberi G, Achar YJ, Giannattasio M, Foiani M. Sen1 and Rrm3 ensure permissive topological conditions for replication termination. Cell Rep 2023; 42:112747. [PMID: 37405920 DOI: 10.1016/j.celrep.2023.112747] [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: 10/01/2022] [Revised: 04/17/2023] [Accepted: 06/20/2023] [Indexed: 07/07/2023] Open
Abstract
Replication forks terminate at TERs and telomeres. Forks that converge or encounter transcription generate topological stress. Combining genetics, genomics, and transmission electron microscopy, we find that Rrm3hPif1 and Sen1hSenataxin helicases assist termination at TERs; Sen1 specifically acts at telomeres. rrm3 and sen1 genetically interact and fail to terminate replication, exhibiting fragility at termination zones (TERs) and telomeres. sen1rrm3 accumulates RNA-DNA hybrids and X-shaped gapped or reversed converging forks at TERs; sen1, but not rrm3, builds up RNA polymerase II (RNPII) at TERs and telomeres. Rrm3 and Sen1 restrain Top1 and Top2 activities, preventing toxic accumulation of positive supercoil at TERs and telomeres. We suggest that Rrm3 and Sen1 coordinate the activities of Top1 and Top2 when forks encounter transcription head on or codirectionally, respectively, thus preventing the slowing down of DNA and RNA polymerases. Hence Rrm3 and Sen1 are indispensable to generate permissive topological conditions for replication termination.
Collapse
Affiliation(s)
- Ramveer Choudhary
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Joanna Niska-Blakie
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Mohamood Adhil
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Giordano Liberi
- Istituto di Genetica Molecolare "Luigi Luca Cavalli-Sforza," CNR, Pavia, Italy
| | | | - Michele Giannattasio
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy; Università degli Studi di Milano, Via Festa del Perdono, 7, 20122 Milan, Italy
| | - Marco Foiani
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy; Università degli Studi di Milano, Via Festa del Perdono, 7, 20122 Milan, Italy.
| |
Collapse
|
23
|
Qiao YP, Ren CL, Ma YQ. Two Different Ways of Stress Release in Supercoiled DNA Minicircles under DNA Nick. J Phys Chem B 2023; 127:4015-4021. [PMID: 37126597 DOI: 10.1021/acs.jpcb.2c08618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
It is generally believed that DNA nick is an effective way to release stress in supercoiled DNA, resulting from the twisting motion that individual strands rotate around the axis of the DNA helix. Here, we use MD simulations based on the oxDNA model to investigate the relaxation of 336 bp supercoiled minicircular DNA under DNA nick. Our simulations show that stress release, characterized by the abrupt decrease in linking number, may be induced by two types of DNA motion depending on the nick position. Except for the twisting motion, there is a writhing motion, that is, double strands collectively rotating with one plectoneme removal, which may occur in the process of DNA relaxation with the nick position in the loop region. Moreover, the writhing motion is more likely to occur in the DNA with relatively high hardness, such as C-G pairs. Our simulation results uncover the relationship between structural transformation, stress release, and DNA motion during the dynamic process under DNA nick, indicating the influence of nick position on the relaxation of the supercoiled DNA.
Collapse
Affiliation(s)
- Ye-Peng Qiao
- National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Chun-Lai Ren
- National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yu-Qiang Ma
- National Laboratory of Solid State Microstructures and Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| |
Collapse
|
24
|
Yang LL, Li YC, Xia TJ, Li S, Feng X, Li C, Xie FY, Ou XH, Ma JY. Dynamic of centromere associated RNAs and the centromere loading of DNA repair proteins in growing oocytes. Front Genet 2023; 14:1131698. [PMID: 37035744 PMCID: PMC10080056 DOI: 10.3389/fgene.2023.1131698] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 03/16/2023] [Indexed: 04/11/2023] Open
Abstract
Mammalian centromeres are generally composed of dispersed repeats and the satellites such as α-satellites in human and major/minor satellites in mouse. Transcription of centromeres by RNA polymerase II is evolutionary conserved and critical for kinetochore assembly. In addition, it has been found that the transcribed satellite RNAs can bind DNA repair proteins such as MRE11 and PRKDC, and excessively expressed satellite RNAs could induce genome instability and facilitate tumorigenesis. During the maturation of female oocyte, centromeres are critical for accurate segregation of homologous chromosomes and sister chromatids. However, the dynamics of oocyte centromere transcription and whether it associated with DNA repair proteins are unknown. In this study, we found the transcription of centromeres is active in growing oocytes but it is silenced when oocytes are fully grown. DNA repair proteins like Mlh1, Mre11 and Prkdc are found associated with the minor satellites and this association can be interfered by RNA polymerase II inhibitor α-amanitin. When the growing oocyte is in vitro matured, Mlh1/Mre11/Prkdc foci would release from centromeres to the ooplasm. If the oocytes are treated with Mre11 inhibitor Mirin, the meiosis resumption of growing oocytes with Mre11 foci can be suppressed. These data revealed the dynamic of centromeric transcription in oocytes and its potential association with DNA repair proteins, which provide clues about how oocytes maintain centromere stability and assemble kinetochores.
Collapse
Affiliation(s)
- Lin-Li Yang
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Yan-Chu Li
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Tian-Jin Xia
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Sen Li
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xie Feng
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Chao Li
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng-Yun Xie
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xiang-Hong Ou
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
- *Correspondence: Xiang-Hong Ou, ; Jun-Yu Ma,
| | - Jun-Yu Ma
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Fertilization Preservation Lab, Guangdong-Hong Kong Metabolism and Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
- *Correspondence: Xiang-Hong Ou, ; Jun-Yu Ma,
| |
Collapse
|
25
|
Influence of Single Deuterium Replacement on Frequency of Hydrogen Bond Dissociation in IFNA17 under the Highest Critical Energy Range. Int J Mol Sci 2022; 23:ijms232415487. [PMID: 36555136 PMCID: PMC9778762 DOI: 10.3390/ijms232415487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/02/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
The effect of single substitutions of protium for deuterium in hydrogen bonds between pairs of nitrogenous bases on the open states occurrence probability at high critical breaking energies of these bonds has been studied. The study was carried out using numerical methods based on the angular mathematical model of DNA. The IFNA17 gene was divided into three approximately equal parts. A comparison of the open states occurrence probability in these parts of the gene was done. To improve the accuracy of the results, a special data processing algorithm was developed. The developed methods have shown their suitability for taking into account the occurrence of open states in the entire range of high critical energies. It has been established that single 2H/1H substitutions in certain nitrogenous bases can be a mechanism for maintaining the vital activity of IFNA17 under critical conditions. In general, the developed method of the mathematical modeling provide unprecedented insight into the DNA behavior under the highest critical energy range, which greatly expands scientific understanding of nucleobases interaction.
Collapse
|
26
|
Masnovo C, Lobo AF, Mirkin SM. Replication dependent and independent mechanisms of GAA repeat instability. DNA Repair (Amst) 2022; 118:103385. [PMID: 35952488 PMCID: PMC9675320 DOI: 10.1016/j.dnarep.2022.103385] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/28/2022] [Accepted: 07/30/2022] [Indexed: 11/20/2022]
Abstract
Trinucleotide repeat instability is a driver of human disease. Large expansions of (GAA)n repeats in the first intron of the FXN gene are the cause Friedreich's ataxia (FRDA), a progressive degenerative disorder which cannot yet be prevented or treated. (GAA)n repeat instability arises during both replication-dependent processes, such as cell division and intergenerational transmission, as well as in terminally differentiated somatic tissues. Here, we provide a brief historical overview on the discovery of (GAA)n repeat expansions and their association to FRDA, followed by recent advances in the identification of triplex H-DNA formation and replication fork stalling. The main body of this review focuses on the last decade of progress in understanding the mechanism of (GAA)n repeat instability during DNA replication and/or DNA repair. We propose that the discovery of additional mechanisms of (GAA)n repeat instability can be achieved via both comparative approaches to other repeat expansion diseases and genome-wide association studies. Finally, we discuss the advances towards FRDA prevention or amelioration that specifically target (GAA)n repeat expansions.
Collapse
Affiliation(s)
- Chiara Masnovo
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Ayesha F Lobo
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, MA 02155, USA.
| |
Collapse
|
27
|
Joyeux M. Models of topological barriers and molecular motors of bacterial DNA. MOLECULAR SIMULATION 2022. [DOI: 10.1080/08927022.2022.2120626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Marc Joyeux
- Laboratoire Interdisciplinaire de Physique, CNRS and Université Grenoble Alpes, Grenoble, France
| |
Collapse
|
28
|
Tan BG, Mutti CD, Shi Y, Xie X, Zhu X, Silva-Pinheiro P, Menger KE, Díaz-Maldonado H, Wei W, Nicholls TJ, Chinnery PF, Minczuk M, Falkenberg M, Gustafsson CM. The human mitochondrial genome contains a second light strand promoter. Mol Cell 2022; 82:3646-3660.e9. [PMID: 36044900 DOI: 10.1016/j.molcel.2022.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/21/2022] [Accepted: 08/07/2022] [Indexed: 11/30/2022]
Abstract
The human mitochondrial genome must be replicated and expressed in a timely manner to maintain energy metabolism and supply cells with adequate levels of adenosine triphosphate. Central to this process is the idea that replication primers and gene products both arise via transcription from a single light strand promoter (LSP) such that primer formation can influence gene expression, with no consensus as to how this is regulated. Here, we report the discovery of a second light strand promoter (LSP2) in humans, with features characteristic of a bona fide mitochondrial promoter. We propose that the position of LSP2 on the mitochondrial genome allows replication and gene expression to be orchestrated from two distinct sites, which expands our long-held understanding of mitochondrial gene expression in humans.
Collapse
Affiliation(s)
- Benedict G Tan
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 405 30, Sweden
| | - Christian D Mutti
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Yonghong Shi
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 405 30, Sweden
| | - Xie Xie
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 405 30, Sweden
| | - Xuefeng Zhu
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 405 30, Sweden
| | - Pedro Silva-Pinheiro
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK
| | - Katja E Menger
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Héctor Díaz-Maldonado
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 405 30, Sweden
| | - Wei Wei
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Thomas J Nicholls
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Patrick F Chinnery
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK.
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 405 30, Sweden.
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 405 30, Sweden.
| |
Collapse
|
29
|
Han S, Lim KS, Blackburn BJ, Yun J, Putnam CW, Bull DA, Won YW. The Potential of Topoisomerase Inhibitor-Based Antibody–Drug Conjugates. Pharmaceutics 2022; 14:pharmaceutics14081707. [PMID: 36015333 PMCID: PMC9413092 DOI: 10.3390/pharmaceutics14081707] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/08/2022] [Accepted: 08/11/2022] [Indexed: 12/17/2022] Open
Abstract
DNA topoisomerases are essential enzymes that stabilize DNA supercoiling and resolve entanglements. Topoisomerase inhibitors have been widely used as anti-cancer drugs for the past 20 years. Due to their selectivity as topoisomerase I (TOP1) inhibitors that trap TOP1 cleavage complexes, camptothecin and its derivatives are promising anti-cancer drugs. To increase accumulation of TOP1 inhibitors in cancer cells through the targeting of tumors, TOP1 inhibitor antibody–drug conjugates (TOP1-ADC) have been developed and marketed. Some TOP1-ADCs have shown enhanced therapeutic efficacy compared to prototypical anti-cancer ADCs, such as T-DM1. Here, we review various types of camptothecin-based TOP1 inhibitors and recent developments in TOP1-ADCs. We then propose key points for the design and construction of TOP1-ADCs. Finally, we discuss promising combinatorial strategies, including newly developed approaches to maximizing the therapeutic potential of TOP1-ADCs.
Collapse
Affiliation(s)
- Seungmin Han
- Division of Cardiothoracic Surgery, Department of Surgery, University of Arizona College of Medicine—Tucson, Tucson, AZ 85724, USA
| | - Kwang Suk Lim
- Department of Biotechnology and Bioengineering, College of Art, Culture and Engineering, Kangwon National University, Chuncheon 24341, Korea
- Department of Smart Health Science and Technology, College of Art, Culture and Engineering, Kangwon National University, Chuncheon 24341, Korea
| | - Brody J. Blackburn
- Department of Medical Pharmacology, University of Arizona College of Medicine—Tucson, Tucson, AZ 85724, USA
| | - Jina Yun
- Division of Hematology-Oncology, Department of Medicine, Soonchunhyang University Bucheon Hospital, Bucheon 14584, Korea
| | - Charles W. Putnam
- Division of Cardiothoracic Surgery, Department of Surgery, University of Arizona College of Medicine—Tucson, Tucson, AZ 85724, USA
| | - David A. Bull
- Division of Cardiothoracic Surgery, Department of Surgery, University of Arizona College of Medicine—Tucson, Tucson, AZ 85724, USA
| | - Young-Wook Won
- Division of Cardiothoracic Surgery, Department of Surgery, University of Arizona College of Medicine—Tucson, Tucson, AZ 85724, USA
- Correspondence:
| |
Collapse
|
30
|
Dash S, Palma CSD, Baptista ISC, Almeida BLB, Bahrudeen MNM, Chauhan V, Jagadeesan R, Ribeiro AS. Alteration of DNA supercoiling serves as a trigger of short-term cold shock repressed genes of E. coli. Nucleic Acids Res 2022; 50:8512-8528. [PMID: 35920318 PMCID: PMC9410904 DOI: 10.1093/nar/gkac643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/07/2022] [Accepted: 07/20/2022] [Indexed: 11/14/2022] Open
Abstract
Cold shock adaptability is a key survival skill of gut bacteria of warm-blooded animals. Escherichia coli cold shock responses are controlled by a complex multi-gene, timely-ordered transcriptional program. We investigated its underlying mechanisms. Having identified short-term, cold shock repressed genes, we show that their responsiveness is unrelated to their transcription factors or global regulators, while their single-cell protein numbers' variability increases after cold shock. We hypothesized that some cold shock repressed genes could be triggered by high propensity for transcription locking due to changes in DNA supercoiling (likely due to DNA relaxation caused by an overall reduction in negative supercoiling). Concomitantly, we found that nearly half of cold shock repressed genes are also highly responsive to gyrase inhibition (albeit most genes responsive to gyrase inhibition are not cold shock responsive). Further, their response strengths to cold shock and gyrase inhibition correlate. Meanwhile, under cold shock, nucleoid density increases, and gyrases and nucleoid become more colocalized. Moreover, the cellular energy decreases, which may hinder positive supercoils resolution. Overall, we conclude that sensitivity to diminished negative supercoiling is a core feature of E. coli's short-term, cold shock transcriptional program, and could be used to regulate the temperature sensitivity of synthetic circuits.
Collapse
Affiliation(s)
- Suchintak Dash
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Cristina S D Palma
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Ines S C Baptista
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Bilena L B Almeida
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Mohamed N M Bahrudeen
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Vatsala Chauhan
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Rahul Jagadeesan
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Andre S Ribeiro
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland.,Center of Technology and Systems (CTS-Uninova), NOVA University of Lisbon 2829-516, Monte de Caparica, Portugal
| |
Collapse
|
31
|
Yi J, Yeou S, Lee NK. DNA Bending Force Facilitates Z-DNA Formation under Physiological Salt Conditions. J Am Chem Soc 2022; 144:13137-13145. [PMID: 35839423 PMCID: PMC9335521 DOI: 10.1021/jacs.2c02466] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Z-DNA, a noncanonical helical structure of double-stranded DNA (dsDNA), plays pivotal roles in various biological processes, including transcription regulation. Mechanical stresses on dsDNA, such as twisting and stretching, help to form Z-DNA. However, the effect of DNA bending, one of the most common dsDNA deformations, on Z-DNA formation is utterly unknown. Here, we show that DNA bending induces the formation of Z-DNA, that is, more Z-DNA is formed as the bending force becomes stronger. We regulated the bending force on dsDNA by using D-shaped DNA nanostructures. The B-Z transition was observed by single-molecule fluorescence resonance energy transfer. We found that as the bending force became stronger, Z-DNA was formed at lower Mg2+ concentrations. When dsDNA contained cytosine methylations, the B-Z transition occurred at 78 mM Mg2+ (midpoint) in the absence of the bending force. However, the B-Z transition occurred at a 28-fold lower Mg2+ concentration (2.8 mM) in the presence of the bending force. Monte Carlo simulation suggested that the B-Z transition stabilizes the bent form via the formation of the B-Z junction with base extrusion, which effectively releases the bending stress on DNA. Our results clearly show that the bending force facilitates the B-Z transition under physiological salt conditions.
Collapse
Affiliation(s)
- Jaehun Yi
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Sanghun Yeou
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Nam Ki Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| |
Collapse
|
32
|
Khazeem MM, Casement JW, Schlossmacher G, Kenneth NS, Sumbung NK, Chan JYT, McGow JF, Cowell IG, Austin CA. TOP2B Is Required to Maintain the Adrenergic Neural Phenotype and for ATRA-Induced Differentiation of SH-SY5Y Neuroblastoma Cells. Mol Neurobiol 2022; 59:5987-6008. [PMID: 35831557 PMCID: PMC9463316 DOI: 10.1007/s12035-022-02949-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 06/23/2022] [Indexed: 12/13/2022]
Abstract
The neuroblastoma cell line SH-SY5Y is widely used to study retinoic acid (RA)-induced gene expression and differentiation and as a tool to study neurodegenerative disorders. SH-SY5Y cells predominantly exhibit adrenergic neuronal properties, but they can also exist in an epigenetically interconvertible alternative state with more mesenchymal characteristics; as a result, these cells can be used to study gene regulation circuitry controlling neuroblastoma phenotype. Using a combination of pharmacological inhibition and targeted gene inactivation, we have probed the requirement for DNA topoisomerase IIB (TOP2B) in RA-induced gene expression and differentiation and in the balance between adrenergic neuronal versus mesenchymal transcription programmes. We found that expression of many, but not all genes that are rapidly induced by ATRA in SH-SY5Y cells was significantly reduced in the TOP2B null cells; these genes include BCL2, CYP26A1, CRABP2, and NTRK2. Comparing gene expression profiles in wild-type versus TOP2B null cells, we found that long genes and genes expressed at a high level in WT SH-SY5Y cells were disproportionately dependent on TOP2B. Notably, TOP2B null SH-SY5Y cells upregulated mesenchymal markers vimentin (VIM) and fibronectin (FN1) and components of the NOTCH signalling pathway. Enrichment analysis and comparison with the transcription profiles of other neuroblastoma-derived cell lines supported the conclusion that TOP2B is required to fully maintain the adrenergic neural-like transcriptional signature of SH-SY5Y cells and to suppress the alternative mesenchymal epithelial-like epigenetic state.
Collapse
Affiliation(s)
- Mushtaq M Khazeem
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,National Center of Hematology, Mustansiriyah University, Baghdad, Iraq
| | - John W Casement
- Bioinformatics Support Unit, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - George Schlossmacher
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Niall S Kenneth
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Nielda K Sumbung
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Janice Yuen Tung Chan
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Jade F McGow
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Ian G Cowell
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Caroline A Austin
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| |
Collapse
|
33
|
Bowater RP, Bohálová N, Brázda V. Interaction of Proteins with Inverted Repeats and Cruciform Structures in Nucleic Acids. Int J Mol Sci 2022; 23:ijms23116171. [PMID: 35682854 PMCID: PMC9180970 DOI: 10.3390/ijms23116171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/26/2022] [Accepted: 05/30/2022] [Indexed: 01/27/2023] Open
Abstract
Cruciforms occur when inverted repeat sequences in double-stranded DNA adopt intra-strand hairpins on opposing strands. Biophysical and molecular studies of these structures confirm their characterization as four-way junctions and have demonstrated that several factors influence their stability, including overall chromatin structure and DNA supercoiling. Here, we review our understanding of processes that influence the formation and stability of cruciforms in genomes, covering the range of sequences shown to have biological significance. It is challenging to accurately sequence repetitive DNA sequences, but recent advances in sequencing methods have deepened understanding about the amounts of inverted repeats in genomes from all forms of life. We highlight that, in the majority of genomes, inverted repeats are present in higher numbers than is expected from a random occurrence. It is, therefore, becoming clear that inverted repeats play important roles in regulating many aspects of DNA metabolism, including replication, gene expression, and recombination. Cruciforms are targets for many architectural and regulatory proteins, including topoisomerases, p53, Rif1, and others. Notably, some of these proteins can induce the formation of cruciform structures when they bind to DNA. Inverted repeat sequences also influence the evolution of genomes, and growing evidence highlights their significance in several human diseases, suggesting that the inverted repeat sequences and/or DNA cruciforms could be useful therapeutic targets in some cases.
Collapse
Affiliation(s)
- Richard P. Bowater
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK;
| | - Natália Bohálová
- Department of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics of the Czech Academy of Sciences, 61265 Brno, Czech Republic;
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Václav Brázda
- Department of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics of the Czech Academy of Sciences, 61265 Brno, Czech Republic;
- Correspondence:
| |
Collapse
|
34
|
Dzhimak S, Svidlov A, Elkina A, Gerasimenko E, Baryshev M, Drobotenko M. Genesis of Open States Zones in a DNA Molecule Depends on the Localization and Value of the Torque. Int J Mol Sci 2022; 23:ijms23084428. [PMID: 35457247 PMCID: PMC9025193 DOI: 10.3390/ijms23084428] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 03/31/2022] [Accepted: 04/15/2022] [Indexed: 11/24/2022] Open
Abstract
The formation and dynamics of the open states in a double-stranded DNA molecule are largely determined by its mechanical parameters. The main one is the torque. However, the experimental study of DNA dynamics and the occurrence of open states is limited by the spatial resolution of available biophysical instruments. Therefore, in this work, on the basis of a mechanical mathematical model of DNA, calculations of the torque effect on the process of occurrence and dynamics of open states were carried out for the interferon alpha 17 gene. It was shown that torsion action leads to the occurrence of rotational movements of nitrogenous bases. This influence is nonlinear, and an increase in the amplitude of the torsion action does not lead to an automatic increase in the amplitude of rotational movements and an increase in the zones’ open states. Calculations with a constant torsion moment demonstrate that open states zones are more often formed at the boundaries of the gen and in regions with a predominance of A–T pairs. It is shown, that for the occurrence of open states in the part of the gene that contains a small number of A–T pairs, a large amount of torque is required. When the torque is applied to a certain region of the gene, the probability of the formation of the open state depends on the content of A–T pairs in this region, the size of this region, and on the exposure time. For this mathematical model, open states zones can be closed when the torsion action stops. The simulation results showed that the values of the torsion moment required for the appearance of open states zones, in some cases, are close to experimentally measured (13–15 pN·nm).
Collapse
Affiliation(s)
- Stepan Dzhimak
- Department of Radiophysics and Nanothechnology, Physics Faculty, Kuban State University, 350040 Krasnodar, Russia; (A.S.); (A.E.); (M.B.); (M.D.)
- Laboratory of Problems of Stable Isotope Spreading in Living Systems, Federal Research Center the Southern Scientific Center of the Russian Academy of Sciences, 344006 Rostov-on-Don, Russia
- Correspondence: ; Tel.: +7-905-408-36-12
| | - Alexandr Svidlov
- Department of Radiophysics and Nanothechnology, Physics Faculty, Kuban State University, 350040 Krasnodar, Russia; (A.S.); (A.E.); (M.B.); (M.D.)
- Laboratory of Problems of Stable Isotope Spreading in Living Systems, Federal Research Center the Southern Scientific Center of the Russian Academy of Sciences, 344006 Rostov-on-Don, Russia
| | - Anna Elkina
- Department of Radiophysics and Nanothechnology, Physics Faculty, Kuban State University, 350040 Krasnodar, Russia; (A.S.); (A.E.); (M.B.); (M.D.)
- Laboratory of Problems of Stable Isotope Spreading in Living Systems, Federal Research Center the Southern Scientific Center of the Russian Academy of Sciences, 344006 Rostov-on-Don, Russia
| | - Eugeny Gerasimenko
- Department of Technology of Fats, Cosmetics, Commodity Science, Processes and Devices, Kuban State Technological University, 350072 Krasnodar, Russia;
| | - Mikhail Baryshev
- Department of Radiophysics and Nanothechnology, Physics Faculty, Kuban State University, 350040 Krasnodar, Russia; (A.S.); (A.E.); (M.B.); (M.D.)
- Laboratory of Problems of Stable Isotope Spreading in Living Systems, Federal Research Center the Southern Scientific Center of the Russian Academy of Sciences, 344006 Rostov-on-Don, Russia
- Department of Technology of Fats, Cosmetics, Commodity Science, Processes and Devices, Kuban State Technological University, 350072 Krasnodar, Russia;
| | - Mikhail Drobotenko
- Department of Radiophysics and Nanothechnology, Physics Faculty, Kuban State University, 350040 Krasnodar, Russia; (A.S.); (A.E.); (M.B.); (M.D.)
| |
Collapse
|
35
|
Pommier Y, Nussenzweig A, Takeda S, Austin C. Human topoisomerases and their roles in genome stability and organization. Nat Rev Mol Cell Biol 2022; 23:407-427. [PMID: 35228717 PMCID: PMC8883456 DOI: 10.1038/s41580-022-00452-3] [Citation(s) in RCA: 116] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2022] [Indexed: 12/15/2022]
Abstract
Human topoisomerases comprise a family of six enzymes: two type IB (TOP1 and mitochondrial TOP1 (TOP1MT), two type IIA (TOP2A and TOP2B) and two type IA (TOP3A and TOP3B) topoisomerases. In this Review, we discuss their biochemistry and their roles in transcription, DNA replication and chromatin remodelling, and highlight the recent progress made in understanding TOP3A and TOP3B. Because of recent advances in elucidating the high-order organization of the genome through chromatin loops and topologically associating domains (TADs), we integrate the functions of topoisomerases with genome organization. We also discuss the physiological and pathological formation of irreversible topoisomerase cleavage complexes (TOPccs) as they generate topoisomerase DNA–protein crosslinks (TOP-DPCs) coupled with DNA breaks. We discuss the expanding number of redundant pathways that repair TOP-DPCs, and the defects in those pathways, which are increasingly recognized as source of genomic damage leading to neurological diseases and cancer. Topoisomerases have essential roles in transcription, DNA replication, chromatin remodelling and, as recently revealed, 3D genome organization. However, topoisomerases also generate DNA–protein crosslinks coupled with DNA breaks, which are increasingly recognized as a source of disease-causing genomic damage.
Collapse
|
36
|
Lim W, Randisi F, Doye JPK, Louis AA. The interplay of supercoiling and thymine dimers in DNA. Nucleic Acids Res 2022; 50:2480-2492. [PMID: 35188542 PMCID: PMC8934635 DOI: 10.1093/nar/gkac082] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/21/2022] [Accepted: 02/04/2022] [Indexed: 11/16/2022] Open
Abstract
Thymine dimers are a major mutagenic photoproduct induced by UV radiation. While they have been the subject of extensive theoretical and experimental investigations, questions of how DNA supercoiling affects local defect properties, or, conversely, how the presence of such defects changes global supercoiled structure, are largely unexplored. Here, we introduce a model of thymine dimers in the oxDNA forcefield, parametrized by comparison to melting experiments and structural measurements of the thymine dimer induced bend angle. We performed extensive molecular dynamics simulations of double-stranded DNA as a function of external twist and force. Compared to undamaged DNA, the presence of a thymine dimer lowers the supercoiling densities at which plectonemes and bubbles occur. For biologically relevant supercoiling densities and forces, thymine dimers can preferentially segregate to the tips of the plectonemes, where they enhance the probability of a localized tip-bubble. This mechanism increases the probability of highly bent and denatured states at the thymine dimer site, which may facilitate repair enzyme binding. Thymine dimer-induced tip-bubbles also pin plectonemes, which may help repair enzymes to locate damage. We hypothesize that the interplay of supercoiling and local defects plays an important role for a wider set of DNA damage repair systems.
Collapse
Affiliation(s)
- Wilber Lim
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - Ferdinando Randisi
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK
- FabricNano Limited, 192 Drummond St, London NW1 3HP, UK
| | - Jonathan P K Doye
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK
| | - Ard A Louis
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| |
Collapse
|
37
|
Gao X, Inman JT, Wang MD. Angular Optical Trapping to Directly Measure DNA Torsional Mechanics. Methods Mol Biol 2022; 2478:37-73. [PMID: 36063318 DOI: 10.1007/978-1-0716-2229-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Angular optical trapping (AOT) is a powerful technique that permits direct angular manipulation of a trapped particle with simultaneous measurement of torque and rotation, while also retaining the capabilities of position and force detection. This technique provides unique approaches to investigate the torsional properties of nucleic acids and DNA-protein complexes, as well as impacts of torsional stress on fundamental biological processes, such as transcription and replication. Here we describe the principle, construction, and calibration of the AOT in detail and provide a guide to the performance of single-molecule torque measurements on DNA molecules. We include the constant-force method and, notably, a new constant-extension method that enables measurement of the twist persistence length of both extended DNA, under an extremely low force, and plectonemic DNA. This chapter can assist in the implementation and application of this technique for general researchers in the single-molecule field.
Collapse
Affiliation(s)
- Xiang Gao
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, USA
- Laboratory of Atomic and Solid State Physics (LASSP), Department of Physics, Cornell University, Ithaca, NY, USA
| | - James T Inman
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, USA
- Laboratory of Atomic and Solid State Physics (LASSP), Department of Physics, Cornell University, Ithaca, NY, USA
| | - Michelle D Wang
- Howard Hughes Medical Institute, Cornell University, Ithaca, NY, USA.
- Laboratory of Atomic and Solid State Physics (LASSP), Department of Physics, Cornell University, Ithaca, NY, USA.
| |
Collapse
|
38
|
Watson GD, Chan EW, Leake MC, Noy A. Structural interplay between DNA-shape protein recognition and supercoiling: The case of IHF. Comput Struct Biotechnol J 2022; 20:5264-5274. [PMID: 36212531 PMCID: PMC9519438 DOI: 10.1016/j.csbj.2022.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 09/12/2022] [Accepted: 09/12/2022] [Indexed: 11/03/2022] Open
|
39
|
The bacterial promoter spacer modulates promoter strength and timing by length, TG-motifs and DNA supercoiling sensitivity. Sci Rep 2021; 11:24399. [PMID: 34937877 PMCID: PMC8695583 DOI: 10.1038/s41598-021-03817-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 12/09/2021] [Indexed: 01/25/2023] Open
Abstract
Transcription, the first step to gene expression, is a central coordination process in all living matter. Besides a plethora of regulatory mechanisms, the promoter architecture sets the foundation of expression strength, timing and the potential for further regulatory modulation. In this study, we investigate the effects of promoter spacer length and sequence composition on strength and supercoiling sensitivity in bacteria. Combining transcriptomics data analysis and standardized synthetic promoter libraries, we exclude effects of specific promoter sequence contexts. Analysis of promoter activity shows a strong variance with spacer length and spacer sequence composition. A detailed study of the spacer sequence composition under selective conditions reveals an extension to the -10 region that enhances RNAP binding but damps promoter activity. Using physiological changes in DNA supercoiling levels, we link promoter supercoiling sensitivity to overall spacer GC-content. Time-resolved promoter activity screens, only possible with a novel mild treatment approach, reveal strong promoter timing potentials solely based on DNA supercoiling sensitivity in the absence of regulatory sites or alternative sigma factors.
Collapse
|
40
|
Zhang X, Garrett S, Graveley BR, Terns MP. Unique properties of spacer acquisition by the type III-A CRISPR-Cas system. Nucleic Acids Res 2021; 50:1562-1582. [PMID: 34893878 PMCID: PMC8860593 DOI: 10.1093/nar/gkab1193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/12/2021] [Accepted: 11/19/2021] [Indexed: 12/11/2022] Open
Abstract
Type III CRISPR-Cas systems have a unique mode of interference, involving crRNA-guided recognition of nascent RNA and leading to DNA and RNA degradation. How type III systems acquire new CRISPR spacers is currently not well understood. Here, we characterize CRISPR spacer uptake by a type III-A system within its native host, Streptococcus thermophilus. Adaptation by the type II-A system in the same host provided a basis for comparison. Cas1 and Cas2 proteins were critical for type III adaptation but deletion of genes responsible for crRNA biogenesis or interference did not detectably change spacer uptake patterns, except those related to host counter-selection. Unlike the type II-A system, type III spacers are acquired in a PAM- and orientation-independent manner. Interestingly, certain regions of plasmids and the host genome were particularly well-sampled during type III-A, but not type II-A, spacer uptake. These regions included the single-stranded origins of rolling-circle replicating plasmids, rRNA and tRNA encoding gene clusters, promoter regions of expressed genes and 5′ UTR regions involved in transcription attenuation. These features share the potential to form DNA secondary structures, suggesting a preferred substrate for type III adaptation. Lastly, the type III-A system adapted to and protected host cells from lytic phage infection.
Collapse
Affiliation(s)
- Xinfu Zhang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Sandra Garrett
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.,Department of Microbiology, University of Georgia, Athens, GA 30602, USA.,Department of Genetics, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
41
|
Sanchez-Contreras M, Sweetwyne MT, Kohrn BF, Tsantilas KA, Hipp MJ, Schmidt EK, Fredrickson J, Whitson JA, Campbell MD, Rabinovitch PS, Marcinek DJ, Kennedy SR. A replication-linked mutational gradient drives somatic mutation accumulation and influences germline polymorphisms and genome composition in mitochondrial DNA. Nucleic Acids Res 2021; 49:11103-11118. [PMID: 34614167 PMCID: PMC8565317 DOI: 10.1093/nar/gkab901] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 11/22/2022] Open
Abstract
Mutations in mitochondrial DNA (mtDNA) cause maternally inherited diseases, while somatic mutations are linked to common diseases of aging. Although mtDNA mutations impact health, the processes that give rise to them are under considerable debate. To investigate the mechanism by which de novo mutations arise, we analyzed the distribution of naturally occurring somatic mutations across the mouse and human mtDNA obtained by Duplex Sequencing. We observe distinct mutational gradients in G→A and T→C transitions delimited by the light-strand origin and the mitochondrial Control Region (mCR). The gradient increases unequally across the mtDNA with age and is lost in the absence of DNA polymerase γ proofreading activity. In addition, high-resolution analysis of the mCR shows that important regulatory elements exhibit considerable variability in mutation frequency, consistent with them being mutational ‘hot-spots’ or ‘cold-spots’. Collectively, these patterns support genome replication via a deamination prone asymmetric strand-displacement mechanism as the fundamental driver of mutagenesis in mammalian DNA. Moreover, the distribution of mtDNA single nucleotide polymorphisms in humans and the distribution of bases in the mtDNA across vertebrate species mirror this gradient, indicating that replication-linked mutations are likely the primary source of inherited polymorphisms that, over evolutionary timescales, influences genome composition during speciation.
Collapse
Affiliation(s)
- Monica Sanchez-Contreras
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Mariya T Sweetwyne
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Brendan F Kohrn
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | | | - Michael J Hipp
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Elizabeth K Schmidt
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Jeanne Fredrickson
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Jeremy A Whitson
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Matthew D Campbell
- Department of Radiology, University of Washington, Seattle, WA 98195, USA
| | - Peter S Rabinovitch
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - David J Marcinek
- Department of Radiology, University of Washington, Seattle, WA 98195, USA
| | - Scott R Kennedy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| |
Collapse
|
42
|
TOP2B's contributions to transcription. Biochem Soc Trans 2021; 49:2483-2493. [PMID: 34747992 DOI: 10.1042/bst20200454] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/07/2021] [Accepted: 10/11/2021] [Indexed: 12/23/2022]
Abstract
Transcription is regulated and mediated by multiprotein complexes in a chromatin context. Transcription causes changes in DNA topology which is modulated by DNA topoisomerases, enzymes that catalyse changes in DNA topology via transient breaking and re-joining of one or both strands of the phosphodiester backbone. Mammals have six DNA topoisomerases, this review focuses on one, DNA topoisomerase II beta (TOP2B). In the absence of TOP2B transcription of many developmentally regulated genes is altered. Long genes seem particularly susceptible to the lack of TOP2B. Biochemical studies of the role of TOP2B in transcription regulated by ligands such as nuclear hormones, growth factors and insulin has revealed PARP1 associated with TOP2B and also PRKDC, XRCC5 and XRCC6. Analysis of publicly available databases of protein interactions confirms these interactions and illustrates interactions with other key transcriptional regulators including TRIM28. TOP2B has been shown to interact with proteins involved in chromosome organisation including CTCF and RAD21. Comparison of publicly available Chip-seq datasets reveals the location at which these proteins interact with genes. The availability of resources such as large datasets of protein-protein interactions, e.g. BioGrid and IntAct and protein-DNA interactions such as Chip-seq in GEO enables scientists to extend models and propose new hypotheses.
Collapse
|
43
|
Duprey A, Groisman EA. The regulation of DNA supercoiling across evolution. Protein Sci 2021; 30:2042-2056. [PMID: 34398513 PMCID: PMC8442966 DOI: 10.1002/pro.4171] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/04/2021] [Accepted: 08/04/2021] [Indexed: 11/11/2022]
Abstract
DNA supercoiling controls a variety of cellular processes, including transcription, recombination, chromosome replication, and segregation, across all domains of life. As a physical property, DNA supercoiling alters the double helix structure by under- or over-winding it. Intriguingly, the evolution of DNA supercoiling reveals both similarities and differences in its properties and regulation across the three domains of life. Whereas all organisms exhibit local, constrained DNA supercoiling, only bacteria and archaea exhibit unconstrained global supercoiling. DNA supercoiling emerges naturally from certain cellular processes and can also be changed by enzymes called topoisomerases. While structurally and mechanistically distinct, topoisomerases that dissipate excessive supercoils exist in all domains of life. By contrast, topoisomerases that introduce positive or negative supercoils exist only in bacteria and archaea. The abundance of topoisomerases is also transcriptionally and post-transcriptionally regulated in domain-specific ways. Nucleoid-associated proteins, metabolites, and physicochemical factors influence DNA supercoiling by acting on the DNA itself or by impacting the activity of topoisomerases. Overall, the unique strategies that organisms have evolved to regulate DNA supercoiling hold significant therapeutic potential, such as bactericidal agents that target bacteria-specific processes or anticancer drugs that hinder abnormal DNA replication by acting on eukaryotic topoisomerases specialized in this process. The investigation of DNA supercoiling therefore reveals general principles, conserved mechanisms, and kingdom-specific variations relevant to a wide range of biological questions.
Collapse
Affiliation(s)
- Alexandre Duprey
- Department of Microbial PathogenesisYale School of MedicineNew HavenConnecticutUSA
| | - Eduardo A. Groisman
- Department of Microbial PathogenesisYale School of MedicineNew HavenConnecticutUSA
- Yale Microbial Sciences InstituteWest HavenConnecticutUSA
| |
Collapse
|
44
|
The spatial position effect: synthetic biology enters the era of 3D genomics. Trends Biotechnol 2021; 40:539-548. [PMID: 34607694 DOI: 10.1016/j.tibtech.2021.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 11/23/2022]
Abstract
Microbial cell factories are critical to achieving green biomanufacturing. A position effect occurs when a synthetic gene circuit is expressed from different positions in the chassis strain genome. Here, we propose the concept of the 'spatial position effect,' which uses technologies in 3D genomics to reveal the spatial structure characteristics of the 3D genome of the chassis. On this basis, we propose to rationally design the integration sites of synthetic gene circuits, use reporter genes for preliminary screening, and integrate synthetic gene circuits into promising sites for further experiments. This approach can produce stable and efficient chassis strains for green biomanufacturing. The proposed spatial position effect brings synthetic biology into the era of 3D genomics.
Collapse
|
45
|
Fogg JM, Judge AK, Stricker E, Chan HL, Zechiedrich L. Supercoiling and looping promote DNA base accessibility and coordination among distant sites. Nat Commun 2021; 12:5683. [PMID: 34584096 PMCID: PMC8478907 DOI: 10.1038/s41467-021-25936-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 08/30/2021] [Indexed: 11/29/2022] Open
Abstract
DNA in cells is supercoiled and constrained into loops and this supercoiling and looping influence every aspect of DNA activity. We show here that negative supercoiling transmits mechanical stress along the DNA backbone to disrupt base pairing at specific distant sites. Cooperativity among distant sites localizes certain sequences to superhelical apices. Base pair disruption allows sharp bending at superhelical apices, which facilitates DNA writhing to relieve torsional strain. The coupling of these processes may help prevent extensive denaturation associated with genomic instability. Our results provide a model for how DNA can form short loops, which are required for many essential processes, and how cells may use DNA loops to position nicks to facilitate repair. Furthermore, our results reveal a complex interplay between site-specific disruptions to base pairing and the 3-D conformation of DNA, which influences how genomes are stored, replicated, transcribed, repaired, and many other aspects of DNA activity.
Collapse
Affiliation(s)
- Jonathan M Fogg
- Department of Molecular Virology and Microbiology, Houston, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Houston, TX, USA
- Department of Pharmacology and Chemical Biology, Houston, TX, USA
| | - Allison K Judge
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Houston, TX, USA
| | - Erik Stricker
- Department of Molecular Virology and Microbiology, Houston, TX, USA
| | - Hilda L Chan
- Graduate Program in Immunology and Microbiology, Houston, TX, USA
- Medical Scientist Training Program, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA
| | - Lynn Zechiedrich
- Department of Molecular Virology and Microbiology, Houston, TX, USA.
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Houston, TX, USA.
- Department of Pharmacology and Chemical Biology, Houston, TX, USA.
- Graduate Program in Immunology and Microbiology, Houston, TX, USA.
| |
Collapse
|
46
|
Wu T, Nance J, Chu F, Fazzio TG. Characterization of R-Loop-Interacting Proteins in Embryonic Stem Cells Reveals Roles in rRNA Processing and Gene Expression. Mol Cell Proteomics 2021; 20:100142. [PMID: 34478875 PMCID: PMC8461376 DOI: 10.1016/j.mcpro.2021.100142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 08/21/2021] [Accepted: 08/25/2021] [Indexed: 12/14/2022] Open
Abstract
Chromatin-associated RNAs have diverse roles in the nucleus. However, their mechanisms of action are poorly understood, in part because of the inability to identify proteins that specifically associate with chromatin-bound RNAs. Here, we address this problem for a subset of chromatin-associated RNAs that form R-loops-RNA-DNA hybrid structures that include a displaced strand of ssDNA. R-loops generally form cotranscriptionally and have important roles in regulation of gene expression, immunoglobulin class switching, and other processes. However, unresolved R-loops can lead to DNA damage and chromosome instability. To identify factors that may bind and regulate R-loop accumulation or mediate R-loop-dependent functions, we used a comparative immunoprecipitation/MS approach, with and without RNA-protein crosslinking, to identify a stringent set of R-loop-binding proteins in mouse embryonic stem cells. We identified 364 R-loop-interacting proteins, which were highly enriched for proteins with predicted RNA-binding functions. We characterized several R-loop-interacting proteins of the DEAD-box family of RNA helicases and found that these proteins localize to the nucleolus and, to a lesser degree, the nucleus. Consistent with their localization patterns, we found that these helicases are required for rRNA processing and regulation of gene expression. Surprisingly, depletion of these helicases resulted in misregulation of highly overlapping sets of protein-coding genes, including many genes that function in differentiation and development. We conclude that R-loop-interacting DEAD-box helicases have nonredundant roles that are critical for maintaining the normal embryonic stem cell transcriptome.
Collapse
Affiliation(s)
- Tong Wu
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jennifer Nance
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Feixia Chu
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Thomas G Fazzio
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
| |
Collapse
|
47
|
Qian J, Xu W, Dunlap D, Finzi L. Single-molecule insights into torsion and roadblocks in bacterial transcript elongation. Transcription 2021; 12:219-231. [PMID: 34719335 PMCID: PMC8632135 DOI: 10.1080/21541264.2021.1997315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 12/12/2022] Open
Abstract
During transcription, RNA polymerase (RNAP) translocates along the helical template DNA while maintaining high transcriptional fidelity. However, all genomes are dynamically twisted, writhed, and decorated by bound proteins and motor enzymes. In prokaryotes, proteins bound to DNA, specifically or not, frequently compact DNA into conformations that may silence genes by obstructing RNAP. Collision of RNAPs with these architectural proteins, may result in RNAP stalling and/or displacement of the protein roadblock. It is important to understand how rapidly transcribing RNAPs operate under different levels of supercoiling or in the presence of roadblocks. Given the broad range of asynchronous dynamics exhibited by transcriptional complexes, single-molecule assays, such as atomic force microscopy, fluorescence detection, optical and magnetic tweezers, etc. are well suited for detecting and quantifying activity with adequate spatial and temporal resolution. Here, we summarize current understanding of the effects of torsion and roadblocks on prokaryotic transcription, with a focus on single-molecule assays that provide real-time detection and readout.
Collapse
Affiliation(s)
- Jin Qian
- Emory University, Atlanta, GA, USA
| | | | | | | |
Collapse
|
48
|
Xiang Y, Surovtsev IV, Chang Y, Govers SK, Parry BR, Liu J, Jacobs-Wagner C. Interconnecting solvent quality, transcription, and chromosome folding in Escherichia coli. Cell 2021; 184:3626-3642.e14. [PMID: 34186018 DOI: 10.1016/j.cell.2021.05.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 12/09/2020] [Accepted: 05/25/2021] [Indexed: 12/12/2022]
Abstract
All cells fold their genomes, including bacterial cells, where the chromosome is compacted into a domain-organized meshwork called the nucleoid. How compaction and domain organization arise is not fully understood. Here, we describe a method to estimate the average mesh size of the nucleoid in Escherichia coli. Using nucleoid mesh size and DNA concentration estimates, we find that the cytoplasm behaves as a poor solvent for the chromosome when the cell is considered as a simple semidilute polymer solution. Monte Carlo simulations suggest that a poor solvent leads to chromosome compaction and DNA density heterogeneity (i.e., domain formation) at physiological DNA concentration. Fluorescence microscopy reveals that the heterogeneous DNA density negatively correlates with ribosome density within the nucleoid, consistent with cryoelectron tomography data. Drug experiments, together with past observations, suggest the hypothesis that RNAs contribute to the poor solvent effects, connecting chromosome compaction and domain formation to transcription and intracellular organization.
Collapse
Affiliation(s)
- Yingjie Xiang
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Ivan V Surovtsev
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Yunjie Chang
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06510, USA
| | - Sander K Govers
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA; Department of Biology and Institute of Chemistry, Engineering and Medicine for Human Health, Stanford University, Palo Alto, CA 94305, USA
| | - Bradley R Parry
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Jun Liu
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06510, USA
| | - Christine Jacobs-Wagner
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06510, USA; Department of Biology and Institute of Chemistry, Engineering and Medicine for Human Health, Stanford University, Palo Alto, CA 94305, USA.
| |
Collapse
|
49
|
Patel YD, Brown AJ, Zhu J, Rosignoli G, Gibson SJ, Hatton D, James DC. Control of Multigene Expression Stoichiometry in Mammalian Cells Using Synthetic Promoters. ACS Synth Biol 2021; 10:1155-1165. [PMID: 33939428 PMCID: PMC8296667 DOI: 10.1021/acssynbio.0c00643] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Indexed: 01/22/2023]
Abstract
To successfully engineer mammalian cells for a desired purpose, multiple recombinant genes are required to be coexpressed at a specific and optimal ratio. In this study, we hypothesized that synthetic promoters varying in transcriptional activity could be used to create single multigene expression vectors coexpressing recombinant genes at a predictable relative stoichiometry. A library of 27 multigene constructs was created comprising three discrete fluorescent reporter gene transcriptional units in fixed series, each under the control of either a relatively low, medium, or high transcriptional strength synthetic promoter in every possible combination. Expression of each reporter gene was determined by absolute quantitation qRT-PCR in CHO cells. The synthetic promoters did generally function as designed within a multigene vector context; however, significant divergences from predicted promoter-mediated transcriptional activity were observed. First, expression of all three genes within a multigene vector was repressed at varying levels relative to coexpression of identical reporter genes on separate single gene vectors at equivalent gene copies. Second, gene positional effects were evident across all constructs where expression of the reporter genes in positions 2 and 3 was generally reduced relative to position 1. Finally, after accounting for general repression, synthetic promoter transcriptional activity within a local multigene vector format deviated from that expected. Taken together, our data reveal that mammalian synthetic promoters can be employed in vectors to mediate expression of multiple genes at predictable relative stoichiometries. However, empirical validation of functional performance is a necessary prerequisite, as vector and promoter design features can significantly impact performance.
Collapse
Affiliation(s)
- Yash D. Patel
- Department
of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, U.K.
| | - Adam J. Brown
- Department
of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, U.K.
| | - Jie Zhu
- Cell
Culture and Fermentation Sciences, BioPharmaceuticals Development,
R&D, AstraZeneca, Gaithersburg, Maryland 20878, United States
| | - Guglielmo Rosignoli
- Dynamic
Omics, Antibody Discovery & Protein Engineering, R&D, AstraZeneca, Cambridge, CB21 6GH, U.K.
| | - Suzanne J. Gibson
- Cell
Culture and Fermentation Sciences, BioPharmaceuticals Development,
R&D, AstraZeneca, Cambridge, CB21 6GH, U.K.
| | - Diane Hatton
- Cell
Culture and Fermentation Sciences, BioPharmaceuticals Development,
R&D, AstraZeneca, Cambridge, CB21 6GH, U.K.
| | - David C. James
- Department
of Chemical and Biological Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, U.K.
| |
Collapse
|
50
|
Klindziuk A, Kolomeisky AB. Long-Range Supercoiling-Mediated RNA Polymerase Cooperation in Transcription. J Phys Chem B 2021; 125:4692-4700. [PMID: 33913709 DOI: 10.1021/acs.jpcb.1c01859] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is widely believed that DNA supercoiling plays an important role in the regulation of transcriptional dynamics. Recent studies show that it could affect transcription not only through the buildup and relaxation of torsional strain on DNA strands but also via effective long-range supercoiling-mediated interactions between RNA polymerase (RNAP) molecules. Here, we present a theoretical study that quantitatively analyzes the effect of long-range RNAP cooperation in transcription dynamics. Our minimal chemical-kinetic model assumes that one or two RNAP molecules can simultaneously participate in the transcription, and it takes into account their binding to and dissociation from DNA. It also explicitly accounts for competition between the supercoiling buildup that reduces the RNA elongation speed and gyrase binding that rescues the RNA synthesis. The full analytical solution of the model accompanied by Monte Carlo computer simulations predicts that the system should exhibit transcriptional bursting dynamics, in agreement with experimental observations. The analysis also revealed that when there are two polymerases participating in the elongation rather than one, the transcription process becomes much more efficient since the level of stochastic noise decreases while more RNA transcripts are produced. Our theoretical investigation clarifies molecular aspects of the supercoiling-mediated RNAP cooperativity during transcription.
Collapse
Affiliation(s)
- Alena Klindziuk
- Department of Chemistry, Rice University, Houston, Texas 77005, United States.,Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
| | - Anatoly B Kolomeisky
- Department of Chemistry, Rice University, Houston, Texas 77005, United States.,Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States.,Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States.,Department of Physics and Astronomy, Rice University, Houston, Texas 77005, United States
| |
Collapse
|