1
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Obermeyer S, Kapoor H, Markusch H, Grasser KD. Transcript elongation by RNA polymerase II in plants: factors, regulation and impact on gene expression. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 118:645-656. [PMID: 36703573 DOI: 10.1111/tpj.16115] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/12/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Transcriptional elongation by RNA polymerase II (RNAPII) through chromatin is a dynamic and highly regulated step of eukaryotic gene expression. A combination of transcript elongation factors (TEFs) including modulators of RNAPII activity and histone chaperones facilitate efficient transcription on nucleosomal templates. Biochemical and genetic analyses, primarily performed in Arabidopsis, provided insight into the contribution of TEFs to establish gene expression patterns during plant growth and development. In addition to summarising the role of TEFs in plant gene expression, we emphasise in our review recent advances in the field. Thus, mechanisms are presented how aberrant intragenic transcript initiation is suppressed by repressing transcriptional start sites within coding sequences. We also discuss how transcriptional interference of ongoing transcription with neighbouring genes is prevented. Moreover, it appears that plants make no use of promoter-proximal RNAPII pausing in the way mammals do, but there are nucleosome-defined mechanism(s) that determine the efficiency of mRNA synthesis by RNAPII. Accordingly, a still growing number of processes related to plant growth, development and responses to changing environmental conditions prove to be regulated at the level of transcriptional elongation.
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Affiliation(s)
- Simon Obermeyer
- Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Henna Kapoor
- Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Hanna Markusch
- Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
| | - Klaus D Grasser
- Cell Biology and Plant Biochemistry, Biochemistry Centre, University of Regensburg, Universitätsstr. 31, D-93053, Regensburg, Germany
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2
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Santana JF, Spector BM, Suarez G, Luse D, Price D. NELF focuses sites of initiation and maintains promoter architecture. Nucleic Acids Res 2024; 52:2977-2994. [PMID: 38197272 PMCID: PMC11014283 DOI: 10.1093/nar/gkad1253] [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: 09/26/2023] [Revised: 11/29/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024] Open
Abstract
Many factors control the elongation phase of transcription by RNA polymerase II (Pol II), a process that plays an essential role in regulating gene expression. We utilized cells expressing degradation tagged subunits of NELFB, PAF1 and RTF1 to probe the effects of depletion of the factors on nascent transcripts using PRO-Seq and on chromatin architecture using DFF-ChIP. Although NELF is involved in promoter proximal pausing, depletion of NELFB had only a minimal effect on the level of paused transcripts and almost no effect on control of productive elongation. Instead, NELF depletion increased the utilization of downstream transcription start sites and caused a dramatic, genome-wide loss of H3K4me3 marked nucleosomes. Depletion of PAF1 and RTF1 both had major effects on productive transcript elongation in gene bodies and also caused initiation site changes like those seen with NELFB depletion. Our study confirmed that the first nucleosome encountered during initiation and early elongation is highly positioned with respect to the major TSS. In contrast, the positions of H3K4me3 marked nucleosomes in promoter regions are heterogeneous and are influenced by transcription. We propose a model defining NELF function and a general role of the H3K4me3 modification in blocking transcription initiation.
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Affiliation(s)
- Juan F Santana
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Benjamin M Spector
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Gustavo A Suarez
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Donal S Luse
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - David H Price
- Department of Biochemistry and Molecular Biology, The University of Iowa, Iowa City, IA 52242, USA
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3
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Su BG, Vos SM. Distinct negative elongation factor conformations regulate RNA polymerase II promoter-proximal pausing. Mol Cell 2024; 84:1243-1256.e5. [PMID: 38401543 PMCID: PMC10997474 DOI: 10.1016/j.molcel.2024.01.023] [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: 10/11/2023] [Revised: 12/17/2023] [Accepted: 01/25/2024] [Indexed: 02/26/2024]
Abstract
Metazoan gene expression regulation involves pausing of RNA polymerase (Pol II) in the promoter-proximal region of genes and is stabilized by DSIF and NELF. Upon depletion of elongation factors, NELF appears to accompany elongating Pol II past pause sites; however, prior work indicates that NELF prevents Pol II elongation. Here, we report cryoelectron microscopy structures of Pol II-DSIF-NELF complexes with NELF in two distinct conformations corresponding to paused and poised states. The paused NELF state supports Pol II stalling, whereas the poised NELF state enables transcription elongation as it does not support a tilted RNA-DNA hybrid. Further, the poised NELF state can accommodate TFIIS binding to Pol II, allowing for Pol II reactivation at paused or backtracking sites. Finally, we observe that the NELF-A tentacle interacts with the RPB2 protrusion and is necessary for pausing. Our results define how NELF can support pausing, reactivation, and elongation by Pol II.
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Affiliation(s)
- Bonnie G Su
- Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, USA
| | - Seychelle M Vos
- Department of Biology, Massachusetts Institute of Technology, Building 68, 31 Ames St., Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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4
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Chen P, Li G, Li W. Nucleosome Dynamics Derived at the Single-Molecule Level Bridges Its Structures and Functions. JACS AU 2024; 4:866-876. [PMID: 38559720 PMCID: PMC10976579 DOI: 10.1021/jacsau.3c00658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 04/04/2024]
Abstract
Nucleosome, the building block of chromatin, plays pivotal roles in all DNA-related processes. While cryogenic-electron microscopy (cryo-EM) has significantly advanced our understanding of nucleosome structures, the emerging field of single-molecule force spectroscopy is illuminating their dynamic properties. This technique is crucial for revealing how nucleosome behavior is influenced by chaperones, remodelers, histone variants, and post-translational modifications, particularly in their folding and unfolding mechanisms under tension. Such insights are vital for deciphering the complex interplay in nucleosome assembly and structural regulation, highlighting the nucleosome's versatility in response to DNA activities. In this Perspective, we aim to consolidate the latest advancements in nucleosome dynamics, with a special focus on the revelations brought forth by single-molecule manipulation. Our objective is to highlight the insights gained from studying nucleosome dynamics through this innovative approach, emphasizing the transformative impact of single-molecule manipulation techniques in the field of chromatin research.
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Affiliation(s)
- Ping Chen
- National
Laboratory of Biomacromolecules and Key Laboratory of Epigenetic Regulation
and Intervention, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
- Department
of Immunology, School of Basic Medical Sciences, Beijing Key Laboratory
for Tumor Invasion and Metastasis, Capital
Medical University, Beijing 100069, P. R. China
| | - Guohong Li
- National
Laboratory of Biomacromolecules and Key Laboratory of Epigenetic Regulation
and Intervention, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
- University
of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Wei Li
- National
Laboratory of Biomacromolecules and Key Laboratory of Epigenetic Regulation
and Intervention, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P. R. China
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5
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Sekine SI, Ehara H, Kujirai T, Kurumizaka H. Structural perspectives on transcription in chromatin. Trends Cell Biol 2024; 34:211-224. [PMID: 37596139 DOI: 10.1016/j.tcb.2023.07.011] [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: 04/21/2023] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/20/2023]
Abstract
In eukaryotes, all genetic processes take place in the cell nucleus, where DNA is packaged as chromatin in 'beads-on-a-string' nucleosome arrays. RNA polymerase II (RNAPII) transcribes protein-coding and many non-coding genes in this chromatin environment. RNAPII elongates RNA while passing through multiple nucleosomes and maintaining the integrity of the chromatin structure. Recent structural studies have shed light on the detailed mechanisms of this process, including how transcribing RNAPII progresses through a nucleosome and reassembles it afterwards, and how transcription elongation factors, chromatin remodelers, and histone chaperones participate in these processes. Other studies have also illuminated the crucial role of nucleosomes in preinitiation complex assembly and transcription initiation. In this review we outline these advances and discuss future perspectives.
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Affiliation(s)
- 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.
| | - Haruhiko Ehara
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Tomoya Kujirai
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan; Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hitoshi Kurumizaka
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan; Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
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6
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Jacobs RQ, Schneider DA. Transcription elongation mechanisms of RNA polymerases I, II, and III and their therapeutic implications. J Biol Chem 2024; 300:105737. [PMID: 38336292 PMCID: PMC10907179 DOI: 10.1016/j.jbc.2024.105737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024] Open
Abstract
Transcription is a tightly regulated, complex, and essential cellular process in all living organisms. Transcription is comprised of three steps, transcription initiation, elongation, and termination. The distinct transcription initiation and termination mechanisms of eukaryotic RNA polymerases I, II, and III (Pols I, II, and III) have long been appreciated. Recent methodological advances have empowered high-resolution investigations of the Pols' transcription elongation mechanisms. Here, we review the kinetic similarities and differences in the individual steps of Pol I-, II-, and III-catalyzed transcription elongation, including NTP binding, bond formation, pyrophosphate release, and translocation. This review serves as an important summation of Saccharomyces cerevisiae (yeast) Pol I, II, and III kinetic investigations which reveal that transcription elongation by the Pols is governed by distinct mechanisms. Further, these studies illustrate how basic, biochemical investigations of the Pols can empower the development of chemotherapeutic compounds.
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Affiliation(s)
- Ruth Q Jacobs
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David A Schneider
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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7
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Archuleta SR, Goodrich JA, Kugel JF. Mechanisms and Functions of the RNA Polymerase II General Transcription Machinery during the Transcription Cycle. Biomolecules 2024; 14:176. [PMID: 38397413 PMCID: PMC10886972 DOI: 10.3390/biom14020176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Central to the development and survival of all organisms is the regulation of gene expression, which begins with the process of transcription catalyzed by RNA polymerases. During transcription of protein-coding genes, the general transcription factors (GTFs) work alongside RNA polymerase II (Pol II) to assemble the preinitiation complex at the transcription start site, open the promoter DNA, initiate synthesis of the nascent messenger RNA, transition to productive elongation, and ultimately terminate transcription. Through these different stages of transcription, Pol II is dynamically phosphorylated at the C-terminal tail of its largest subunit, serving as a control mechanism for Pol II elongation and a signaling/binding platform for co-transcriptional factors. The large number of core protein factors participating in the fundamental steps of transcription add dense layers of regulation that contribute to the complexity of temporal and spatial control of gene expression within any given cell type. The Pol II transcription system is highly conserved across different levels of eukaryotes; however, most of the information here will focus on the human Pol II system. This review walks through various stages of transcription, from preinitiation complex assembly to termination, highlighting the functions and mechanisms of the core machinery that participates in each stage.
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Affiliation(s)
| | - James A. Goodrich
- Department of Biochemistry, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA;
| | - Jennifer F. Kugel
- Department of Biochemistry, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA;
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8
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Chen X, Xu Y. Interplay between the transcription preinitiation complex and the +1 nucleosome. Trends Biochem Sci 2024; 49:145-155. [PMID: 38218671 DOI: 10.1016/j.tibs.2023.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 11/27/2023] [Accepted: 12/01/2023] [Indexed: 01/15/2024]
Abstract
Eukaryotic transcription starts with the assembly of a preinitiation complex (PIC) on core promoters. Flanking this region is the +1 nucleosome, the first nucleosome downstream of the core promoter. While this nucleosome is rich in epigenetic marks and plays a key role in transcription regulation, how the +1 nucleosome interacts with the transcription machinery has been a long-standing question. Here, we summarize recent structural and functional studies of the +1 nucleosome in complex with the PIC. We specifically focus on how differently organized promoter-nucleosome templates affect the assembly of the PIC and PIC-Mediator on chromatin and result in distinct transcription initiation.
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Affiliation(s)
- Xizi Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, New Cornerstone Science Laboratory, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, New Cornerstone Science Laboratory, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.
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9
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Hardtke HA, Zhang YJ. Collaborators or competitors: the communication between RNA polymerase II and the nucleosome during eukaryotic transcription. Crit Rev Biochem Mol Biol 2024; 59:1-19. [PMID: 38288999 DOI: 10.1080/10409238.2024.2306365] [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: 11/26/2023] [Accepted: 01/12/2024] [Indexed: 04/22/2024]
Abstract
Decades of scientific research have been devoted to unraveling the intricacies of eukaryotic transcription since the groundbreaking discovery of eukaryotic RNA polymerases in the late 1960s. RNA polymerase II, the polymerase responsible for mRNA synthesis, has always attracted the most attention. Despite its structural resemblance to its bacterial counterpart, eukaryotic RNA polymerase II faces a unique challenge in progressing transcription due to the presence of nucleosomes that package DNA in the nuclei. In this review, we delve into the impact of RNA polymerase II and histone signaling on the progression of eukaryotic transcription. We explore the pivotal points of interactions that bridge the RNA polymerase II and histone signaling systems. Finally, we present an analysis of recent cryo-electron microscopy structures, which captured RNA polymerase II-nucleosome complexes at different stages of the transcription cycle. The combination of the signaling crosstalk and the direct visualization of RNA polymerase II-nucleosome complexes provides a deeper understanding of the communication between these two major players in eukaryotic transcription.
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Affiliation(s)
- Haley A Hardtke
- Department of Molecular Biosciences, University of Texas, Austin, TX, USA
| | - Y Jessie Zhang
- Department of Molecular Biosciences, University of Texas, Austin, TX, USA
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10
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Chen Y, Cramer P. RNA polymerase II elongation factors use conserved regulatory mechanisms. Curr Opin Struct Biol 2024; 84:102766. [PMID: 38181687 DOI: 10.1016/j.sbi.2023.102766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/11/2023] [Accepted: 12/13/2023] [Indexed: 01/07/2024]
Abstract
RNA polymerase II (Pol II) transcription is regulated by many elongation factors. Among these factors, TFIIF, PAF-RTF1, ELL and Elongin stimulate mRNA chain elongation by Pol II. Cryo-EM structures of Pol II complexes with these elongation factors now reveal some general principles on how elongation factors bind Pol II and how they stimulate transcription. All four elongation factors contact Pol II at domains external 2 and protrusion, whereas TFIIF and ELL additionally bind the Pol II lobe. All factors apparently stabilize cleft-flanking elements, whereas RTF1 and Elongin additionally approach the active site with a latch element and may influence catalysis or translocation. Due to the shared binding sites on Pol II, factor binding is mutually exclusive, and thus it remains to be studied what determines which elongation factors bind at a certain gene and under which condition.
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Affiliation(s)
- Ying Chen
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.
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11
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García A, Durán L, Sánchez M, González S, Santamaría R, Antequera F. Asymmetrical nucleosomal DNA signatures regulate transcriptional directionality. Cell Rep 2024; 43:113605. [PMID: 38127622 DOI: 10.1016/j.celrep.2023.113605] [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: 02/16/2023] [Revised: 10/03/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
Despite the symmetrical structure of nucleosomes, in vitro studies have shown that transcription proceeds with different efficiency depending on the orientation of the DNA sequence around them. However, it is unclear whether this functional asymmetry is present in vivo and whether it could regulate transcriptional directionality. Here, we report that the proximal and distal halves of nucleosomal DNA contribute differentially to nucleosome stability in the genome. In +1 nucleosomes, this asymmetry facilitates or hinders transcription depending on the orientation of its underlying DNA, and this difference is associated with an asymmetrical interaction between DNA and histones. These properties are encoded in the DNA signature of +1 nucleosomes, since its incorporation in the two orientations into downstream nucleosomes renders them asymmetrically accessible to MNase and inverts the balance between sense and antisense transcription. Altogether, our results show that nucleosomal DNA endows nucleosomes with asymmetrical properties that modulate the directionality of transcription.
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Affiliation(s)
- Alicia García
- Instituto de Biología Funcional y Genómica (IBFG), CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Laura Durán
- Instituto de Biología Funcional y Genómica (IBFG), CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Mar Sánchez
- Instituto de Biología Funcional y Genómica (IBFG), CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Sara González
- Instituto de Biología Funcional y Genómica (IBFG), CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Rodrigo Santamaría
- Departamento de Informática y Automática, Universidad de Salamanca/Facultad de Ciencias, Plaza de los Caídos s/n, 37007 Salamanca, Spain
| | - Francisco Antequera
- Instituto de Biología Funcional y Genómica (IBFG), CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain.
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12
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Boltengagen M, Verhagen D, Wolff MR, Oberbeckmann E, Hanke M, Gerland U, Korber P, Mueller-Planitz F. A single fiber view of the nucleosome organization in eukaryotic chromatin. Nucleic Acids Res 2024; 52:166-185. [PMID: 37994698 PMCID: PMC10783498 DOI: 10.1093/nar/gkad1098] [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: 02/07/2023] [Revised: 10/13/2023] [Accepted: 10/31/2023] [Indexed: 11/24/2023] Open
Abstract
Eukaryotic cells are thought to arrange nucleosomes into extended arrays with evenly spaced nucleosomes phased at genomic landmarks. Here we tested to what extent this stereotypic organization describes the nucleosome organization in Saccharomyces cerevisiae using Fiber-Seq, a long-read sequencing technique that maps entire nucleosome arrays on individual chromatin fibers in a high throughput manner. With each fiber coming from a different cell, Fiber-Seq uncovers cell-to-cell heterogeneity. The long reads reveal the nucleosome architecture even over repetitive DNA such as the ribosomal DNA repeats. The absolute nucleosome occupancy, a parameter that is difficult to obtain with conventional sequencing approaches, is a direct readout of Fiber-Seq. We document substantial deviations from the stereotypical nucleosome organization with unexpectedly long linker DNAs between nucleosomes, gene bodies missing entire nucleosomes, cell-to-cell heterogeneity in nucleosome occupancy, heterogeneous phasing of arrays and irregular nucleosome spacing. Nucleosome array structures are indistinguishable throughout the gene body and with respect to the direction of transcription arguing against transcription promoting array formation. Acute nucleosome depletion destroyed most of the array organization indicating that nucleosome remodelers cannot efficiently pack nucleosomes under those conditions. Given that nucleosomes are cis-regulatory elements, the cell-to-cell heterogeneity uncovered by Fiber-Seq provides much needed information to understand chromatin structure and function.
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Affiliation(s)
- Mark Boltengagen
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Daan Verhagen
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
- Molecular Biology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Michael Roland Wolff
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, Garching, Germany
| | - Elisa Oberbeckmann
- Molecular Biology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Matthias Hanke
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, Garching, Germany
| | - Ulrich Gerland
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, Garching, Germany
| | - Philipp Korber
- Molecular Biology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Felix Mueller-Planitz
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
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13
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Nishimura M, Fujii T, Tanaka H, Maehara K, Morishima K, Shimizu M, Kobayashi Y, Nozawa K, Takizawa Y, Sugiyama M, Ohkawa Y, Kurumizaka H. Genome-wide mapping and cryo-EM structural analyses of the overlapping tri-nucleosome composed of hexasome-hexasome-octasome moieties. Commun Biol 2024; 7:61. [PMID: 38191828 PMCID: PMC10774305 DOI: 10.1038/s42003-023-05694-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 12/11/2023] [Indexed: 01/10/2024] Open
Abstract
The nucleosome is a fundamental unit of chromatin in which about 150 base pairs of DNA are wrapped around a histone octamer. The overlapping di-nucleosome has been proposed as a product of chromatin remodeling around the transcription start site, and previously found as a chromatin unit, in which about 250 base pairs of DNA continuously bind to the histone core composed of a hexamer and an octamer. In the present study, our genome-wide analysis of human cells suggests another higher nucleosome stacking structure, the overlapping tri-nucleosome, which wraps about 300-350 base-pairs of DNA in the region downstream of certain transcription start sites of actively transcribed genes. We determine the cryo-electron microscopy (cryo-EM) structure of the overlapping tri-nucleosome, in which three subnucleosome moieties, hexasome, hexasome, and octasome, are associated by short connecting DNA segments. Small angle X-ray scattering and coarse-grained molecular dynamics simulation analyses reveal that the cryo-EM structure of the overlapping tri-nucleosome may reflect its structure in solution. Our findings suggest that nucleosome stacking structures composed of hexasome and octasome moieties may be formed by nucleosome remodeling factors around transcription start sites for gene regulation.
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Affiliation(s)
- Masahiro Nishimura
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, 111 TW, Alexander Drive, Research Triangle Park, NC, 27707, USA
| | - Takeru Fujii
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka, 812-0054, Japan
| | - Hiroki Tanaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
- Department of Structural Virology, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan
| | - Kazumitsu Maehara
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka, 812-0054, Japan
| | - Ken Morishima
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan-gun, Osaka, 590-0494, Japan
| | - Masahiro Shimizu
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan-gun, Osaka, 590-0494, Japan
| | - Yuki Kobayashi
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Kayo Nozawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8501, Japan
| | - Yoshimasa Takizawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Masaaki Sugiyama
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori, Sennan-gun, Osaka, 590-0494, Japan
| | - Yasuyuki Ohkawa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka, 812-0054, Japan.
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan.
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14
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Gao J, Jishage M, Wang Y, Wang R, Chen M, Zhu Z, Zhang J, Diwu Y, Xu C, Liao S, Roeder RG, Tu X. Structural basis for evolutionarily conserved interactions between TFIIS and Paf1C. Int J Biol Macromol 2023; 253:126764. [PMID: 37696373 PMCID: PMC11164251 DOI: 10.1016/j.ijbiomac.2023.126764] [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: 04/22/2023] [Revised: 09/03/2023] [Accepted: 09/04/2023] [Indexed: 09/13/2023]
Abstract
The elongation factor TFIIS interacts with Paf1C complex to facilitate processive transcription by Pol II. We here determined the crystal structure of the trypanosoma TFIIS LW domain in a complex with the LFG motif of Leo1, as well as the structures of apo-form TFIIS LW domains from trypanosoma, yeast and human. We revealed that all three TFIIS LW domains possess a conserved hydrophobic core that mediates their interactions with Leo1. Intriguingly, the structural study revealed that trypanosoma Leo1 binding induces the TFIIS LW domain to undergo a conformational change reflected in the length and orientation of α6 helix that is absent in the yeast and human counterparts. These differences explain the higher binding affinity of the TFIIS LW domain interacting with Leo1 in trypanosoma than in yeast and human, and indicate species-specific variations in the interactions. Importantly, the interactions between the TFIIS LW domain and an LFG motif of Leo1 were found to be critical for TFIIS to anchor the entire Paf1C complex. Thus, in addition to revealing a detailed structural basis for the TFIIS-Paf1C interaction, our studies also shed light on the origin and evolution of the roles of TFIIS and Paf1C complex in regulation of transcription elongation.
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Affiliation(s)
- Jie Gao
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China; Department of Ophthalmology, The Second Affiliated Hospital of Anhui Medical University, 678 Furong Road, Hefei, Anhui, PR China
| | - Miki Jishage
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10065, USA
| | - Yuzhu Wang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China
| | - Rui Wang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China; Department of Anthropotomy and Histoembryology, Medical College, Henan University of Science and Technology, Luoyang, Henan 471023, PR China
| | - Meng Chen
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China
| | - Zhongliang Zhu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China
| | - Jiahai Zhang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China
| | - Yating Diwu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China
| | - Chao Xu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China
| | - Shanhui Liao
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China.
| | - Robert G Roeder
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10065, USA.
| | - Xiaoming Tu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230022, PR China.
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15
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Markert JW, Vos SM, Farnung L. Structure of the complete Saccharomyces cerevisiae Rpd3S-nucleosome complex. Nat Commun 2023; 14:8128. [PMID: 38065958 PMCID: PMC10709384 DOI: 10.1038/s41467-023-43968-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Acetylation of histones is a key post-translational modification that guides gene expression regulation. In yeast, the class I histone deacetylase containing Rpd3S complex plays a critical role in the suppression of spurious transcription by removing histone acetylation from actively transcribed genes. The S. cerevisiae Rpd3S complex has five subunits (Rpd3, Sin3, Rco1, Eaf3, and Ume1) but its subunit stoichiometry and how the complex engages nucleosomes to achieve substrate specificity remains elusive. Here we report the cryo-EM structure of the complete Rpd3S complex bound to a nucleosome. Sin3 and two copies of subunits Rco1 and Eaf3 encircle the deacetylase subunit Rpd3 and coordinate the positioning of Ume1. The Rpd3S complex binds both trimethylated H3 tails at position lysine 36 and makes multiple additional contacts with the nucleosomal DNA and the H2A-H2B acidic patch. Direct regulation via the Sin3 subunit coordinates binding of the acetylated histone substrate to achieve substrate specificity.
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Affiliation(s)
- Jonathan W Markert
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Seychelle M Vos
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Lucas Farnung
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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16
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Chen Y, Kokic G, Dienemann C, Dybkov O, Urlaub H, Cramer P. Structure of the transcribing RNA polymerase II-Elongin complex. Nat Struct Mol Biol 2023; 30:1925-1935. [PMID: 37932450 PMCID: PMC10716050 DOI: 10.1038/s41594-023-01138-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 09/26/2023] [Indexed: 11/08/2023]
Abstract
Elongin is a heterotrimeric elongation factor for RNA polymerase (Pol) II transcription that is conserved among metazoa. Here, we report three cryo-EM structures of human Elongin bound to transcribing Pol II. The structures show that Elongin subunit ELOA binds the RPB2 side of Pol II and anchors the ELOB-ELOC subunit heterodimer. ELOA contains a 'latch' that binds between the end of the Pol II bridge helix and funnel helices, thereby inducing a conformational change near the polymerase active center. The latch is required for the elongation-stimulatory activity of Elongin, but not for Pol II binding, indicating that Elongin functions by allosterically regulating the conformational mobility of the polymerase active center. Elongin binding to Pol II is incompatible with association of the super elongation complex, PAF1 complex and RTF1, which also contain an elongation-stimulatory latch element.
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Affiliation(s)
- Ying Chen
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Department of Clinical Laboratory, Qilu Hospital of Shandong University, Jinan, China
| | - Goran Kokic
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Christian Dienemann
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Olexandr Dybkov
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- University Medical Center Göttingen, Institute of Clinical Chemistry, Bioanalytics Group, Göttingen, Germany
- Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Göttingen, Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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17
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Akatsu M, Ehara H, Kujirai T, Fujita R, Ito T, Osumi K, Ogasawara M, Takizawa Y, Sekine SI, Kurumizaka H. Cryo-EM structures of RNA polymerase II-nucleosome complexes rewrapping transcribed DNA. J Biol Chem 2023; 299:105477. [PMID: 37981206 PMCID: PMC10703601 DOI: 10.1016/j.jbc.2023.105477] [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: 06/20/2023] [Revised: 10/30/2023] [Accepted: 11/11/2023] [Indexed: 11/21/2023] Open
Abstract
RNA polymerase II (RNAPII) transcribes DNA wrapped in the nucleosome by stepwise pausing, especially at nucleosomal superhelical locations -5 and -1 [SHL(-5) and SHL(-1), respectively]. In the present study, we performed cryo-electron microscopy analyses of RNAPII-nucleosome complexes paused at a major nucleosomal pausing site, SHL(-1). We determined two previously undetected structures, in which the transcribed DNA behind RNAPII is sharply kinked at the RNAPII exit tunnel and rewrapped around the nucleosomal histones in front of RNAPII by DNA looping. This DNA kink shifts the DNA orientation toward the nucleosome, and the transcribed DNA region interacts with basic amino acid residues of histones H2A, H2B, and H3 exposed by the RNAPII-mediated nucleosomal DNA peeling. The DNA loop structure was not observed in the presence of the transcription elongation factors Spt4/5 and Elf1. These RNAPII-nucleosome structures provide important information for understanding the functional relevance of DNA looping during transcription elongation in the nucleosome.
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Affiliation(s)
- Munetaka Akatsu
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Haruhiko Ehara
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Tomoya Kujirai
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan; Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Risa Fujita
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Tomoko Ito
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Ken Osumi
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Mitsuo Ogasawara
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Yoshimasa Takizawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Shun-Ichi Sekine
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan.
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo, Tokyo, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo, Japan; Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan.
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18
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Gallardo A, Dutagaci B. Binding of small molecule inhibitors to RNA polymerase-Spt5 complex impacts RNA and DNA stability. J Comput Aided Mol Des 2023; 38:1. [PMID: 37987925 PMCID: PMC10663202 DOI: 10.1007/s10822-023-00543-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/08/2023] [Indexed: 11/22/2023]
Abstract
Spt5 is an elongation factor that associates with RNA polymerase II (Pol II) during transcription and has important functions in promoter-proximal pausing and elongation processivity. Spt5 was also recognized for its roles in the transcription of expanded-repeat genes that are related to neurodegenerative diseases. Recently, a set of Spt5-Pol II small molecule inhibitors (SPIs) were reported, which selectively inhibit mutant huntingtin gene transcription. Inhibition mechanisms as well as interaction sites of these SPIs with Pol II and Spt5 are not entirely known. In this study, we predicted the binding sites of three selected SPIs at the Pol II-Spt5 interface by docking and molecular dynamics simulations. Two molecules out of three demonstrated strong binding with Spt5 and Pol II, while the other molecule was more loosely bound and sampled multiple binding sites. Strongly bound SPIs indirectly affected RNA and DNA dynamics at the exit site as DNA became more flexible while RNA was stabilized by increased interactions with Spt5. Our results suggest that the transcription inhibition mechanism induced by SPIs can be related to Spt5-nucleic acid interactions, which were altered to some extent with strong binding of SPIs.
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Affiliation(s)
- Adan Gallardo
- Department of Molecular and Cell Biology, University of California Merced, 5200 North Lake Rd, Merced, CA, 95343, USA
| | - Bercem Dutagaci
- Department of Molecular and Cell Biology, University of California Merced, 5200 North Lake Rd, Merced, CA, 95343, USA.
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19
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Robert F, Jeronimo C. Transcription-coupled nucleosome assembly. Trends Biochem Sci 2023; 48:978-992. [PMID: 37657993 DOI: 10.1016/j.tibs.2023.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/21/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
Eukaryotic transcription occurs on chromatin, where RNA polymerase II encounters nucleosomes during elongation. These nucleosomes must unravel for the DNA to enter the active site. However, in most transcribed genes, nucleosomes remain intact due to transcription-coupled chromatin assembly mechanisms. These mechanisms primarily involve the local reassembly of displaced nucleosomes to prevent (epi)genomic instability and the emergence of cryptic transcription. As a fail-safe mechanism, cells can assemble nucleosomes de novo, particularly in highly transcribed genes, but this may result in the loss of epigenetic information. This review examines transcription-coupled chromatin assembly, with an emphasis on studies in yeast and recent structural studies. These studies shed light on how elongation factors and histone chaperones coordinate to enable nucleosome recycling during transcription.
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Affiliation(s)
- François Robert
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada; Département de Médecine, Faculté de Médecine, Université de Montréal, 2900 Boul. Édouard-Montpetit, Montréal, QC H3T 1J4, Canada; Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC H3A 1A3, Canada.
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada
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20
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Miller CLW, Warner JL, Winston F. Insights into Spt6: a histone chaperone that functions in transcription, DNA replication, and genome stability. Trends Genet 2023; 39:858-872. [PMID: 37481442 PMCID: PMC10592469 DOI: 10.1016/j.tig.2023.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/20/2023] [Accepted: 06/23/2023] [Indexed: 07/24/2023]
Abstract
Transcription elongation requires elaborate coordination between the transcriptional machinery and chromatin regulatory factors to successfully produce RNA while preserving the epigenetic landscape. Recent structural and genomic studies have highlighted that suppressor of Ty 6 (Spt6), a conserved histone chaperone and transcription elongation factor, sits at the crux of the transcription elongation process. Other recent studies have revealed that Spt6 also promotes DNA replication and genome integrity. Here, we review recent studies of Spt6 that have provided new insights into the mechanisms by which Spt6 controls transcription and have revealed the breadth of Spt6 functions in eukaryotic cells.
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Affiliation(s)
- Catherine L W Miller
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Laboratory of Genome Maintenance, Rockefeller University, New York, NY 10065, USA
| | - James L Warner
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Fred Winston
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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21
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Farnung L. Nucleosomes unwrapped: Structural perspectives on transcription through chromatin. Curr Opin Struct Biol 2023; 82:102690. [PMID: 37633188 DOI: 10.1016/j.sbi.2023.102690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/02/2023] [Accepted: 08/02/2023] [Indexed: 08/28/2023]
Abstract
Transcription of most protein-coding genes requires the passage of RNA polymerase II through chromatin. Chromatin with its fundamental unit, the nucleosome, represents a barrier to transcription. How RNA polymerase II and associated factors traverse through nucleosomes and how chromatin architecture is maintained have remained largely enigmatic. Only recently, cryo-EM structures have visualized the transcription process through chromatin. These structures have elucidated how transcription initiation and transcription elongation influence and are influenced by a chromatinized DNA substrate. This review provides a summary of our current structural understanding of transcription through chromatin, highlighting common mechanisms during nucleosomal traversal and novel regulatory mechanisms that have emerged in the last five years.
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Affiliation(s)
- Lucas Farnung
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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22
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Fields JK, Hicks CW, Wolberger C. Diverse modes of regulating methyltransferase activity by histone ubiquitination. Curr Opin Struct Biol 2023; 82:102649. [PMID: 37429149 PMCID: PMC10527252 DOI: 10.1016/j.sbi.2023.102649] [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: 03/17/2023] [Revised: 05/29/2023] [Accepted: 06/11/2023] [Indexed: 07/12/2023]
Abstract
Post-translational modification of histones plays a central role in regulating transcription. Methylation of histone H3 at lysines 4 (H3K4) and 79 (H3K79) play roles in activating transcription whereas methylation of H3K27 is a repressive mark. These modifications, in turn, depend upon prior monoubiquitination of specific histone residues in a phenomenon known as histone crosstalk. Earlier work had provided insights into the mechanism by which monoubiquitination histone H2BK120 stimulates H3K4 methylation by COMPASS/MLL1 and H3K79 methylation by DOT1L, and monoubiquitinated H2AK119 stimulates methylation of H3K27 by the PRC2 complex. Recent studies have shed new light on the role of individual subunits and paralogs in regulating the activity of PRC2 and how additional post-translational modifications regulate yeast Dot1 and human DOT1L, as well as provided new insights into the regulation of MLL1 by H2BK120ub.
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Affiliation(s)
- James K Fields
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Chad W Hicks
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Cynthia Wolberger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
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23
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Yang DL, Huang K, Deng D, Zeng Y, Wang Z, Zhang Y. DNA-dependent RNA polymerases in plants. THE PLANT CELL 2023; 35:3641-3661. [PMID: 37453082 PMCID: PMC10533338 DOI: 10.1093/plcell/koad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 06/09/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
DNA-dependent RNA polymerases (Pols) transfer the genetic information stored in genomic DNA to RNA in all organisms. In eukaryotes, the typical products of nuclear Pol I, Pol II, and Pol III are ribosomal RNAs, mRNAs, and transfer RNAs, respectively. Intriguingly, plants possess two additional Pols, Pol IV and Pol V, which produce small RNAs and long noncoding RNAs, respectively, mainly for silencing transposable elements. The five plant Pols share some subunits, but their distinct functions stem from unique subunits that interact with specific regulatory factors in their transcription cycles. Here, we summarize recent advances in our understanding of plant nucleus-localized Pols, including their evolution, function, structures, and transcription cycles.
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Affiliation(s)
- Dong-Lei Yang
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Kun Huang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Deyin Deng
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Lin’an, Hangzhou 311300, China
| | - Yuan Zeng
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Zhenxing Wang
- College of Horticulture, National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
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24
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Goldberg GW, Kogenaru M, Keegan S, Haase MAB, Kagermazova L, Arias MA, Onyebeke K, Adams S, Fenyö D, Noyes MB, Boeke JD. Engineered transcription-associated Cas9 targeting in eukaryotic cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.18.558319. [PMID: 37781609 PMCID: PMC10541143 DOI: 10.1101/2023.09.18.558319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
DNA targeting Class 2 CRISPR-Cas effector nucleases, including the well-studied Cas9 proteins, evolved protospacer-adjacent motif (PAM) and guide RNA interactions that sequentially license their binding and cleavage activities at protospacer target sites. Both interactions are nucleic acid sequence specific but function constitutively; thus, they provide intrinsic spatial control over DNA targeting activities but naturally lack temporal control. Here we show that engineered Cas9 fusion proteins which bind to nascent RNAs near a protospacer can facilitate spatiotemporal coupling between transcription and DNA targeting at that protospacer: Transcription-associated Cas9 Targeting (TraCT). Engineered TraCT is enabled when suboptimal PAM interactions limit basal activity in vivo and when one or more nascent RNA substrates are still tethered to the actively transcribing target DNA in cis. We further show that this phenomenon can be exploited for selective editing at one of two identical targets in distinct gene loci, or, in diploid allelic loci that are differentially transcribed. Our work demonstrates that temporal control over Cas9's targeting activity at specific DNA sites may be engineered without modifying Cas9's core domains and guide RNA components or their expression levels. More broadly, it establishes RNA binding in cis as a mechanism that can conditionally stimulate CRISPR-Cas DNA targeting in eukaryotes.
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Affiliation(s)
- Gregory W. Goldberg
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Manjunatha Kogenaru
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Sarah Keegan
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
- Denotes equivalent contribution to the work
| | - Max A. B. Haase
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
- Denotes equivalent contribution to the work
| | - Larisa Kagermazova
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Mauricio A. Arias
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
| | - Kenenna Onyebeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Samantha Adams
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - David Fenyö
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Marcus B. Noyes
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Jef D. Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn NY 11201
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25
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Dollinger R, Deng EB, Schultz J, Wu S, Deorio HR, Gilmour DS. Assessment of the roles of Spt5-nucleic acid contacts in promoter proximal pausing of RNA polymerase II. J Biol Chem 2023; 299:105106. [PMID: 37517697 PMCID: PMC10482750 DOI: 10.1016/j.jbc.2023.105106] [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: 03/27/2023] [Revised: 07/10/2023] [Accepted: 07/18/2023] [Indexed: 08/01/2023] Open
Abstract
Promoter proximal pausing of RNA polymerase II (Pol II) is a critical transcriptional regulatory mechanism in metazoans that requires the transcription factor DRB sensitivity-inducing factor (DSIF) and the inhibitory negative elongation factor (NELF). DSIF, composed of Spt4 and Spt5, establishes the pause by recruiting NELF to the elongation complex. However, the role of DSIF in pausing beyond NELF recruitment remains unclear. We used a highly purified in vitro system and Drosophila nuclear extract to investigate the role of DSIF in promoter proximal pausing. We identified two domains of Spt5, the KOW4 and NGN domains, that facilitate Pol II pausing. The KOW4 domain promotes pausing through its interaction with the nascent RNA while the NGN domain does so through a short helical motif that is in close proximity to the non-transcribed DNA template strand. Removal of this sequence in Drosophila has a male-specific dominant negative effect. The alpha-helical motif is also needed to support fly viability. We also show that the interaction between the Spt5 KOW1 domain and the upstream DNA helix is required for DSIF association with the Pol II elongation complex. Disruption of the KOW1-DNA interaction is dominant lethal in vivo. Finally, we show that the KOW2-3 domain of Spt5 mediates the recruitment of NELF to the elongation complex. In summary, our results reveal additional roles for DSIF in transcription regulation and identify specific domains important for facilitating Pol II pausing.
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Affiliation(s)
- Roberta Dollinger
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Eilene B Deng
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Josie Schultz
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Sharon Wu
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Haley R Deorio
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA; Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - David S Gilmour
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA.
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26
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Markert JW, Vos SM, Farnung L. Structure of the complete S. cerevisiae Rpd3S-nucleosome complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.03.551877. [PMID: 37577459 PMCID: PMC10418238 DOI: 10.1101/2023.08.03.551877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Acetylation of histones is a key post-translational modification that guides gene expression regulation. In yeast, the class I histone deacetylase containing Rpd3S complex plays a critical role in the suppression of spurious transcription by removing histone acetylation from actively transcribed genes. The Saccharomyces cerevisiae Rpd3S complex has five subunits (Rpd3, Sin3, Rco1, Eaf3, and Ume1) but its subunit stoichiometry and how the complex engages nucleosomes to achieve substrate specificity remains elusive. Here we report the cryo-EM structure of the complete Rpd3S complex bound to a nucleosome. Sin3 and two copies of subunits Rco1 and Eaf3 encircle the deacetylase subunit Rpd3 and coordinate the binding of Ume1. The Rpd3S complex binds both trimethylated H3 tails at position lysine 36 and makes multiple additional contacts with the nucleo-somal DNA, the H2A-H2B acidic patch, and histone H3. Direct regulation via the Sin3 subunit coordinates binding of the acetylated histone substrate to achieve substrate specificity.
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27
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Fisher MJ, Luse DS. Promoter-proximal nucleosomes attenuate RNA polymerase II transcription through TFIID. J Biol Chem 2023; 299:104928. [PMID: 37330174 PMCID: PMC10404688 DOI: 10.1016/j.jbc.2023.104928] [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: 03/02/2023] [Revised: 05/08/2023] [Accepted: 06/08/2023] [Indexed: 06/19/2023] Open
Abstract
A nucleosome is typically positioned with its proximal edge (NPE) ∼50 bp downstream from the transcription start site of metazoan RNA polymerase II promoters. This +1 nucleosome has distinctive characteristics, including the presence of variant histone types and trimethylation of histone H3 at lysine 4. To address the role of these features in transcription complex assembly, we generated templates with four different promoters and nucleosomes located at a variety of downstream positions, which were transcribed in vitro using HeLa nuclear extracts. Two promoters lacked TATA elements, but all supported strong initiation from a single transcription start site. In contrast to results with minimal in vitro systems based on the TATA-binding protein (TBP), TATA promoter templates with a +51 NPE were transcriptionally inhibited in extracts; activity continuously increased as the nucleosome was moved downstream to +100. Inhibition was much more pronounced for the TATA-less promoters: +51 NPE templates were inactive, and substantial activity was only seen with the +100 NPE templates. Substituting the histone variants H2A.Z, H3.3, or both did not eliminate the inhibition. However, addition of excess TBP restored activity on nucleosomal templates with TATA promoters, even with an NPE at +20. Remarkably, nucleosomal templates with histone H3 trimethylated at lysine 4 are active with an NPE at +51 for both TATA and TATA-less promoters. Our results strongly suggest that the +1 nucleosome interferes with promoter recognition by TFIID. This inhibition can be overcome with TBP alone at TATA promoters or through positive interactions with histone modifications and TFIID.
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Affiliation(s)
- Michael J Fisher
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Donal S Luse
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
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28
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Kujirai T, Ehara H, Sekine SI, Kurumizaka H. Structural Transition of the Nucleosome during Transcription Elongation. Cells 2023; 12:1388. [PMID: 37408222 DOI: 10.3390/cells12101388] [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: 04/19/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 07/07/2023] Open
Abstract
In eukaryotes, genomic DNA is tightly wrapped in chromatin. The nucleosome is a basic unit of chromatin, but acts as a barrier to transcription. To overcome this impediment, the RNA polymerase II elongation complex disassembles the nucleosome during transcription elongation. After the RNA polymerase II passage, the nucleosome is rebuilt by transcription-coupled nucleosome reassembly. Nucleosome disassembly-reassembly processes play a central role in preserving epigenetic information, thus ensuring transcriptional fidelity. The histone chaperone FACT performs key functions in nucleosome disassembly, maintenance, and reassembly during transcription in chromatin. Recent structural studies of transcribing RNA polymerase II complexed with nucleosomes have provided structural insights into transcription elongation on chromatin. Here, we review the structural transitions of the nucleosome during transcription.
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Affiliation(s)
- Tomoya Kujirai
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Haruhiko Ehara
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - 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
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
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29
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Cermakova K, Hodges HC. Interaction modules that impart specificity to disordered protein. Trends Biochem Sci 2023; 48:477-490. [PMID: 36754681 PMCID: PMC10106370 DOI: 10.1016/j.tibs.2023.01.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 02/09/2023]
Abstract
Intrinsically disordered regions (IDRs) are especially enriched among proteins that regulate chromatin and transcription. As a result, mechanisms that influence specificity of IDR-driven interactions have emerged as exciting unresolved issues for understanding gene regulation. We review the molecular elements frequently found within IDRs that confer regulatory specificity. In particular, we summarize the differing roles of disordered low-complexity regions (LCRs) and short linear motifs (SLiMs) towards selective nuclear regulation. Examination of IDR-driven interactions highlights SLiMs as organizers of selectivity, with widespread roles in gene regulation and integration of cellular signals. Analysis of recurrent interactions between SLiMs and folded domains suggests diverse avenues for SLiMs to influence phase-separated condensates and highlights opportunities to manipulate these interactions for control of biological activity.
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Affiliation(s)
- Katerina Cermakova
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA
| | - H Courtney Hodges
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA; Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA; Department of Bioengineering, Rice University, Houston, TX, USA; Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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30
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Miller CLW, Winston F. The conserved histone chaperone Spt6 is strongly required for DNA replication and genome stability. Cell Rep 2023; 42:112264. [PMID: 36924499 PMCID: PMC10106089 DOI: 10.1016/j.celrep.2023.112264] [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: 05/06/2022] [Revised: 12/31/2022] [Accepted: 02/27/2023] [Indexed: 03/17/2023] Open
Abstract
Histone chaperones are an important class of proteins that regulate chromatin accessibility for DNA-templated processes. Spt6 is a conserved histone chaperone and key regulator of transcription and chromatin structure. However, its functions outside of these roles have been little explored. In this work, we demonstrate a requirement for S. cerevisiae Spt6 in DNA replication and, more broadly, as a regulator of genome stability. Depletion or mutation of Spt6 impairs DNA replication in vivo. Additionally, spt6 mutants are sensitive to DNA replication stress-inducing agents. Interestingly, this sensitivity is independent of the association of Spt6 with RNA polymerase II (RNAPII), suggesting that spt6 mutants have a transcription-independent impairment of DNA replication. Specifically, genomic studies reveal that spt6 mutants have decreased loading of the MCM replicative helicase at replication origins, suggesting that Spt6 promotes origin licensing. Our results identify Spt6 as a regulator of genome stability, at least in part through a role in DNA replication.
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Affiliation(s)
- Catherine L W Miller
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Fred Winston
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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31
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Are extraordinary nucleosome structures more ordinary than we thought? Chromosoma 2023:10.1007/s00412-023-00791-w. [PMID: 36917245 DOI: 10.1007/s00412-023-00791-w] [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: 01/23/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/16/2023]
Abstract
The nucleosome is a DNA-protein assembly that is the basic unit of chromatin. A nucleosome can adopt various structures. In the canonical nucleosome structure, 145-147 bp of DNA is wrapped around a histone heterooctamer. The strong histone-DNA interactions cause the DNA to be inaccessible for nuclear processes such as transcription. Therefore, the canonical nucleosome structure has to be altered into different, non-canonical structures to increase DNA accessibility. While it is recognised that non-canonical structures do exist, these structures are not well understood. In this review, we discuss both the evidence for various non-canonical nucleosome structures in the nucleus and the factors that are believed to induce these structures. The wide range of non-canonical structures is likely to regulate the amount of accessible DNA, and thus have important nuclear functions.
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32
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The TFIIS N-terminal domain (TND): a transcription assembly module at the interface of order and disorder. Biochem Soc Trans 2023; 51:125-135. [PMID: 36651856 PMCID: PMC9987994 DOI: 10.1042/bst20220342] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/22/2022] [Accepted: 01/03/2023] [Indexed: 01/19/2023]
Abstract
Interaction scaffolds that selectively recognize disordered protein strongly shape protein interactomes. An important scaffold of this type that contributes to transcription is the TFIIS N-terminal domain (TND). The TND is a five-helical bundle that has no known enzymatic activity, but instead selectively reads intrinsically disordered sequences of other proteins. Here, we review the structural and functional properties of TNDs and their cognate disordered ligands known as TND-interacting motifs (TIMs). TNDs or TIMs are found in prominent members of the transcription machinery, including TFIIS, super elongation complex, SWI/SNF, Mediator, IWS1, SPT6, PP1-PNUTS phosphatase, elongin, H3K36me3 readers, the transcription factor MYC, and others. We also review how the TND interactome contributes to the regulation of transcription. Because the TND is the most significantly enriched fold among transcription elongation regulators, TND- and TIM-driven interactions have widespread roles in the regulation of many transcriptional processes.
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33
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Hamamoto K, Umemura Y, Makino S, Fukaya T. Dynamic interplay between non-coding enhancer transcription and gene activity in development. Nat Commun 2023; 14:826. [PMID: 36805453 PMCID: PMC9941499 DOI: 10.1038/s41467-023-36485-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 02/03/2023] [Indexed: 02/22/2023] Open
Abstract
Non-coding transcription at the intergenic regulatory regions is a prevalent feature of metazoan genomes, but its biological function remains uncertain. Here, we devise a live-imaging system that permits simultaneous visualization of gene activity along with intergenic non-coding transcription at single-cell resolution in Drosophila. Quantitative image analysis reveals that elongation of RNA polymerase II across the internal core region of enhancers leads to suppression of transcriptional bursting from linked genes. Super-resolution imaging and genome-editing analysis further demonstrate that enhancer transcription antagonizes molecular crowding of transcription factors, thereby interrupting the formation of a transcription hub at the gene locus. We also show that a certain class of developmental enhancers are structurally optimized to co-activate gene transcription together with non-coding transcription effectively. We suggest that enhancer function is flexibly tunable through the modulation of hub formation via surrounding non-coding transcription during development.
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Affiliation(s)
- Kota Hamamoto
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yusuke Umemura
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Shiho Makino
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takashi Fukaya
- Laboratory of Transcription Dynamics, Research Center for Biological Visualization, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan. .,Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
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34
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Fanourgakis S, Synacheri AC, Lavigne MD, Konstantopoulos D, Fousteri M. Histone H2Bub dynamics in the 5' region of active genes are tightly linked to the UV-induced transcriptional response. Comput Struct Biotechnol J 2022; 21:614-629. [PMID: 36659919 PMCID: PMC9823127 DOI: 10.1016/j.csbj.2022.12.013] [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: 08/15/2022] [Revised: 11/22/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
The timing and location of writing and erasing of histone modifications determine gene expression programs and are tightly controlled processes. One such modification is the monoubiquitination of histone H2B (H2Bub), whose precise level during transcription elongation is dynamically regulated by the synergistic action of RNF20/40 ubiquitin-ligase and the de-ubiquitinase (DUB) of the ATXN7L3-containing DUB modules. Here, we characterize the dynamics of H2Bub in transcription and explore its role in perspective with the recently updated model of UV damage-induced transcription reorganization. Employing integrative analysis of genome-wide high-throughput approaches, transcription inhibitors and ATXN7L3-DUB knockdown cells, we find that H2Bub levels and patterns depend on intron-exon architecture both in steady state and upon UV. Importantly, our analysis reveals a widespread redistribution of this histone mark, rather than a uniform loss as previously suggested, which closely mirrors the post-UV dynamics of elongating RNA Polymerase II (RNAPII) at transcribed loci. The observed effects are due to a direct inter-dependence on RNAPII local concentration and speed, and we show that deficient ATXN7L3-mediated DUB activity leads to increased elongation rates in both non-irradiated and irradiated conditions. Our data and the implementation of a high-resolution computational framework reveal that the H2Bub pattern follows that of RNAPII, both in the ATXNL3 knockdown and in response to UV guaranteeing faithful elongation speed, especially in the context of the transcription-driven DNA damage response.
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35
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Herbert A. Nucleosomes and flipons exchange energy to alter chromatin conformation, the readout of genomic information, and cell fate. Bioessays 2022; 44:e2200166. [DOI: 10.1002/bies.202200166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/24/2022] [Accepted: 09/28/2022] [Indexed: 11/27/2022]
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36
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Chen X, Wang X, Liu W, Ren Y, Qu X, Li J, Yin X, Xu Y. Structures of +1 nucleosome-bound PIC-Mediator complex. Science 2022; 378:62-68. [PMID: 36201575 DOI: 10.1126/science.abn8131] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
RNA polymerase II-mediated eukaryotic transcription starts with the assembly of the preinitiation complex (PIC) on core promoters. The +1 nucleosome is well positioned about 40 base pairs downstream of the transcription start site (TSS) and is commonly known as a barrier of transcription. The +1 nucleosome-bound PIC-Mediator structures show that PIC-Mediator prefers binding to T40N nucleosome located 40 base pairs downstream of TSS and contacts T50N but not the T70N nucleosome. The nucleosome facilitates the organization of PIC-Mediator on the promoter by binding TFIIH subunit p52 and Mediator subunits MED19 and MED26 and may contribute to transcription initiation. PIC-Mediator exhibits multiple nucleosome-binding patterns, supporting a structural role of the +1 nucleosome in the coordination of PIC-Mediator assembly. Our study reveals the molecular mechanism of PIC-Mediator organization on chromatin and underscores the significance of the +1 nucleosome in regulating transcription initiation.
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Affiliation(s)
- Xizi Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xinxin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Weida Liu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yulei Ren
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xuechun Qu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jiabei Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xiaotong Yin
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Shanghai Key Laboratory of Radiation Oncology, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China.,Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China
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37
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Ehara H, Kujirai T, Shirouzu M, Kurumizaka H, Sekine SI. Structural basis of nucleosome disassembly and reassembly by RNAPII elongation complex with FACT. Science 2022; 377:eabp9466. [PMID: 35981082 DOI: 10.1126/science.abp9466] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
During gene transcription, RNA polymerase II (RNAPII) traverses nucleosomes in chromatin, but its mechanism has remained elusive. Using cryo-electron microscopy, we obtained structures of the RNAPII elongation complex (EC) passing through a nucleosome, in the presence of transcription elongation factors Spt6, Spn1, Elf1, Spt4/5, and Paf1C and the histone chaperone FACT. The structures show snapshots of EC progression on DNA, mediating downstream nucleosome disassembly followed by its reassembly upstream of the EC, facilitated by FACT. FACT dynamically adapts to successively occurring subnucleosome intermediates, forming an interface with the EC. Spt6, Spt4/5, and Paf1C form a "cradle" at the EC DNA-exit site, and support the upstream nucleosome reassembly. These structures explain the mechanism by which the EC traverses nucleosomes while maintaining the chromatin structure and epigenetic information.
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Affiliation(s)
- Haruhiko Ehara
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Tomoya Kujirai
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan.,Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Mikako Shirouzu
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Hitoshi Kurumizaka
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan.,Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Shun-Ichi Sekine
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
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