1
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Ren L, Ma W, Wang Y. Predicting RNA polymerase II transcriptional elongation pausing and associated histone code. Brief Bioinform 2024; 25:bbae246. [PMID: 38783706 PMCID: PMC11116834 DOI: 10.1093/bib/bbae246] [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: 01/22/2024] [Revised: 04/12/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
RNA Polymerase II (Pol II) transcriptional elongation pausing is an integral part of the dynamic regulation of gene transcription in the genome of metazoans. It plays a pivotal role in many vital biological processes and disease progression. However, experimentally measuring genome-wide Pol II pausing is technically challenging and the precise governing mechanism underlying this process is not fully understood. Here, we develop RP3 (RNA Polymerase II Pausing Prediction), a network regularized logistic regression machine learning method, to predict Pol II pausing events by integrating genome sequence, histone modification, gene expression, chromatin accessibility, and protein-protein interaction data. RP3 can accurately predict Pol II pausing in diverse cellular contexts and unveil the transcription factors that are associated with the Pol II pausing machinery. Furthermore, we utilize a forward feature selection framework to systematically identify the combination of histone modification signals associated with Pol II pausing. RP3 is freely available at https://github.com/AMSSwanglab/RP3.
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Affiliation(s)
- Lixin Ren
- School of Mathematics and Physics, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Wanbiao Ma
- School of Mathematics and Physics, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Yong Wang
- CEMS, NCMIS, MDIS, Academy of Mathematics and Systems Science, National Center for Mathematics and Interdisciplinary Sciences, Chinese Academy of Sciences, 55 Zhongguancun East Road, Haidian District, Beijing 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, 32 Jiaochang Donglu, Wuhua District, Kunming 650223, China
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 1 Xiangshan Zhi Nong, West Lake District, Hangzhou 330106, China
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2
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Bao Y, Cao X, Landick R. RNA polymerase SI3 domain modulates global transcriptional pausing and pause-site fluctuations. Nucleic Acids Res 2024; 52:4556-4574. [PMID: 38554114 PMCID: PMC11077087 DOI: 10.1093/nar/gkae209] [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: 09/14/2023] [Revised: 03/03/2024] [Accepted: 03/26/2024] [Indexed: 04/01/2024] Open
Abstract
Transcriptional pausing aids gene regulation by cellular RNA polymerases (RNAPs). A surface-exposed domain inserted into the catalytic trigger loop (TL) of Escherichia coli RNAP, called SI3, modulates pausing and is essential for growth. Here we describe a viable E. coli strain lacking SI3 enabled by a suppressor TL substitution (β'Ala941→Thr; ΔSI3*). ΔSI3* increased transcription rate in vitro relative to ΔSI3, possibly explaining its viability, but retained both positive and negative effects of ΔSI3 on pausing. ΔSI3* inhibited pauses stabilized by nascent RNA structures (pause hairpins; PHs) but enhanced other pauses. Using NET-seq, we found that ΔSI3*-enhanced pauses resemble the consensus elemental pause sequence whereas sequences at ΔSI3*-suppressed pauses, which exhibited greater association with PHs, were more divergent. ΔSI3*-suppressed pauses also were associated with apparent pausing one nucleotide upstream from the consensus sequence, often generating tandem pause sites. These '-2 pauses' were stimulated by pyrophosphate in vitro and by addition of apyrase to degrade residual NTPs during NET-seq sample processing. We propose that some pauses are readily reversible by pyrophosphorolysis or single-nucleotide cleavage. Our results document multiple ways that SI3 modulates pausing in vivo and may explain discrepancies in consensus pause sequences in some NET-seq studies.
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Affiliation(s)
- Yu Bao
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Xinyun Cao
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, 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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Yang KB, Rasouly A, Epshtein V, Martinez C, Nguyen T, Shamovsky I, Nudler E. Persistence of backtracking by human RNA polymerase II. Mol Cell 2024; 84:897-909.e4. [PMID: 38340716 DOI: 10.1016/j.molcel.2024.01.019] [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: 08/25/2023] [Revised: 11/20/2023] [Accepted: 01/22/2024] [Indexed: 02/12/2024]
Abstract
RNA polymerase II (RNA Pol II) can backtrack during transcription elongation, exposing the 3' end of nascent RNA. Nascent RNA sequencing can approximate the location of backtracking events that are quickly resolved; however, the extent and genome-wide distribution of more persistent backtracking are unknown. Consequently, we developed a method to directly sequence the extruded, "backtracked" 3' RNA. Our data show that RNA Pol II slides backward more than 20 nt in human cells and can persist in this backtracked state. Persistent backtracking mainly occurs where RNA Pol II pauses near promoters and intron-exon junctions and is enriched in genes involved in translation, replication, and development, where gene expression is decreased if these events are unresolved. Histone genes are highly prone to persistent backtracking, and the resolution of such events is likely required for timely expression during cell division. These results demonstrate that persistent backtracking can potentially affect diverse gene expression programs.
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Affiliation(s)
- Kevin B Yang
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Aviram Rasouly
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA
| | - Vitaly Epshtein
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Criseyda Martinez
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Thao Nguyen
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ilya Shamovsky
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Evgeny Nudler
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA; Howard Hughes Medical Institute, NYU Langone Health, New York, NY 10016, USA.
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5
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Liu L, Zhao Y, Siepel A. DNA-sequence and epigenomic determinants of local rates of transcription elongation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.21.572932. [PMID: 38187771 PMCID: PMC10769381 DOI: 10.1101/2023.12.21.572932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Across all branches of life, transcription elongation is a crucial, regulated phase in gene expression. Many recent studies in eukaryotes have focused on the regulation of promoter-proximal pausing of RNA Polymerase II (Pol II), but rates of productive elongation also vary substantially throughout the gene body, both within and across genes. Here, we introduce a probabilistic model for systematically evaluating potential determinants of the local elongation rate based on nascent RNA sequencing (NRS) data. Our model is derived from a unified model for both the kinetics of Pol II movement along the DNA template and the generation of NRS read counts at steady state. It allows for a continuously variable elongation rate along the gene body, with the rate at each nucleotide defined by a generalized linear relationship with nearby genomic and epigenomic features. High-dimensional feature vectors are accommodated through a sparse-regression extension. We show with simulations that the model allows accurate detection of associated features and accurate prediction of local elongation rates. In an analysis of public PRO-seq and epigenomic data, we identify several features that are strongly associated with reductions in the local elongation rate, including DNA methylation, splice sites, RNA stem-loops, CTCF binding sites, and several histone marks, including H3K36me3 and H4K20me1. By contrast, low-complexity sequences and H3K79me2 marks are associated with increases in elongation rate. In an analysis of DNA k -mers, we find that cytosine nucleotides are strongly associated with reductions in local elongation rate, particularly when preceded by guanines and followed by adenines or thymines. Increases in elongation rate are associated with thymines and A+T-rich k -mers. These associations are generally shared across cell types, and by considering them our model is effective at predicting features of held-out PRO-seq data. Overall, our analysis is the first to permit genome-wide predictions of relative nucleotide-specific elongation rates based on complex sets of genomic and epigenomic covariates. We have made predictions available for the K562, CD14+, MCF-7, and HeLa-S3 cell types in a UCSC Genome Browser track.
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Affiliation(s)
- Lingjie Liu
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY
| | - Yixin Zhao
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | - Adam Siepel
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY
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6
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Yang KB, Rasouly A, Epshtein V, Martinez C, Nguyen T, Shamovsky I, Nudler E. Persistence of backtracking by human RNA polymerase II. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.13.571520. [PMID: 38168453 PMCID: PMC10760130 DOI: 10.1101/2023.12.13.571520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
RNA polymerase II (pol II) can backtrack during transcription elongation, exposing the 3' end of nascent RNA. Nascent RNA sequencing can approximate the location of backtracking events that are quickly resolved; however, the extent and genome wide distribution of more persistent backtracking is unknown. Consequently, we developed a novel method to directly sequence the extruded, "backtracked" 3' RNA. Our data shows that pol II slides backwards more than 20 nucleotides in human cells and can persist in this backtracked state. Persistent backtracking mainly occurs where pol II pauses near promoters and intron-exon junctions, and is enriched in genes involved in translation, replication, and development, where gene expression is decreased if these events are unresolved. Histone genes are highly prone to persistent backtracking, and the resolution of such events is likely required for timely expression during cell division. These results demonstrate that persistent backtracking has the potential to affect diverse gene expression programs.
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7
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Bressin A, Jasnovidova O, Arnold M, Altendorfer E, Trajkovski F, Kratz TA, Handzlik JE, Hnisz D, Mayer A. High-sensitive nascent transcript sequencing reveals BRD4-specific control of widespread enhancer and target gene transcription. Nat Commun 2023; 14:4971. [PMID: 37591883 PMCID: PMC10435483 DOI: 10.1038/s41467-023-40633-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 08/02/2023] [Indexed: 08/19/2023] Open
Abstract
Gene transcription by RNA polymerase II (Pol II) is under control of promoters and distal regulatory elements known as enhancers. Enhancers are themselves transcribed by Pol II correlating with their activity. How enhancer transcription is regulated and coordinated with transcription at target genes has remained unclear. Here, we developed a high-sensitive native elongating transcript sequencing approach, called HiS-NET-seq, to provide an extended high-resolution view on transcription, especially at lowly transcribed regions such as enhancers. HiS-NET-seq uncovers new transcribed enhancers in human cells. A multi-omics analysis shows that genome-wide enhancer transcription depends on the BET family protein BRD4. Specifically, BRD4 co-localizes to enhancer and promoter-proximal gene regions, and is required for elongation activation at enhancers and their genes. BRD4 keeps a set of enhancers and genes in proximity through long-range contacts. From these studies BRD4 emerges as a general regulator of enhancer transcription that may link transcription at enhancers and genes.
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Affiliation(s)
- Annkatrin Bressin
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
- Department of Mathematics and Computer Science, Freie Universität Berlin, 14195, Berlin, Germany
| | - Olga Jasnovidova
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
| | - Mirjam Arnold
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
| | - Elisabeth Altendorfer
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
| | - Filip Trajkovski
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
| | - Thomas A Kratz
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
| | - Joanna E Handzlik
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
| | - Denes Hnisz
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
| | - Andreas Mayer
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany.
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8
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Delbeau M, Omollo EO, Froom R, Koh S, Mooney RA, Lilic M, Brewer JJ, Rock J, Darst SA, Campbell EA, Landick R. Structural and functional basis of the universal transcription factor NusG pro-pausing activity in Mycobacterium tuberculosis. Mol Cell 2023; 83:1474-1488.e8. [PMID: 37116494 PMCID: PMC10231689 DOI: 10.1016/j.molcel.2023.04.007] [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: 10/06/2022] [Revised: 02/08/2023] [Accepted: 04/04/2023] [Indexed: 04/30/2023]
Abstract
Transcriptional pauses mediate regulation of RNA biogenesis. DNA-encoded pause signals trigger pausing by stabilizing RNA polymerase (RNAP) swiveling and inhibiting DNA translocation. The N-terminal domain (NGN) of the only universal transcription factor, NusG/Spt5, modulates pausing through contacts to RNAP and DNA. Pro-pausing NusGs enhance pauses, whereas anti-pausing NusGs suppress pauses. Little is known about pausing and NusG in the human pathogen Mycobacterium tuberculosis (Mtb). We report that MtbNusG is pro-pausing. MtbNusG captures paused, swiveled RNAP by contacts to the RNAP protrusion and nontemplate-DNA wedged between the NGN and RNAP gate loop. In contrast, anti-pausing Escherichia coli (Eco) NGN contacts the MtbRNAP gate loop, inhibiting swiveling and pausing. Using CRISPR-mediated genetics, we show that pro-pausing NGN is required for mycobacterial fitness. Our results define an essential function of mycobacterial NusG and the structural basis of pro- versus anti-pausing NusG activity, with broad implications for the function of all NusG orthologs.
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Affiliation(s)
- Madeleine Delbeau
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Expery O Omollo
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ruby Froom
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA; Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY 10065, USA
| | - Steven Koh
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Rachel A Mooney
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mirjana Lilic
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Joshua J Brewer
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Jeremy Rock
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY 10065, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA.
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA.
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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9
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Akcan TS, Vilov S, Heinig M. Predictive model of transcriptional elongation control identifies trans regulatory factors from chromatin signatures. Nucleic Acids Res 2023; 51:1608-1624. [PMID: 36727445 PMCID: PMC9976927 DOI: 10.1093/nar/gkac1272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/09/2022] [Accepted: 01/12/2023] [Indexed: 02/03/2023] Open
Abstract
Promoter-proximal Polymerase II (Pol II) pausing is a key rate-limiting step for gene expression. DNA and RNA-binding trans-acting factors regulating the extent of pausing have been identified. However, we lack a quantitative model of how interactions of these factors determine pausing, therefore the relative importance of implicated factors is unknown. Moreover, previously unknown regulators might exist. Here we address this gap with a machine learning model that accurately predicts the extent of promoter-proximal Pol II pausing from large-scale genome and transcriptome binding maps and gene annotation and sequence composition features. We demonstrate high accuracy and generalizability of the model by validation on an independent cell line which reveals the model's cell line agnostic character. Model interpretation in light of prior knowledge about molecular functions of regulatory factors confirms the interconnection of pausing with other RNA processing steps. Harnessing underlying feature contributions, we assess the relative importance of each factor, quantify their predictive effects and systematically identify previously unknown regulators of pausing. We additionally identify 16 previously unknown 7SK ncRNA interacting RNA-binding proteins predictive of pausing. Our work provides a framework to further our understanding of the regulation of the critical early steps in transcriptional elongation.
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Affiliation(s)
- Toray S Akcan
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.,Department of Computer Science, TUM School of Computation, Information and Technology, Technical University Munich, Munich, Germany
| | - Sergey Vilov
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Matthias Heinig
- Institute of Computational Biology, Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.,Department of Computer Science, TUM School of Computation, Information and Technology, Technical University Munich, Munich, Germany.,DZHK (German Centre for Cardiovascular Research), Munich Heart Association, Partner Site Munich, 10785 Berlin, Germany
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10
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Kang JY, Mishanina TV, Bao Y, Chen J, Llewellyn E, Liu J, Darst SA, Landick R. An ensemble of interconverting conformations of the elemental paused transcription complex creates regulatory options. Proc Natl Acad Sci U S A 2023; 120:e2215945120. [PMID: 36795753 PMCID: PMC9974457 DOI: 10.1073/pnas.2215945120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/10/2023] [Indexed: 02/17/2023] Open
Abstract
Transcriptional pausing underpins the regulation of cellular RNA synthesis, but its mechanism remains incompletely understood. Sequence-specific interactions of DNA and RNA with the dynamic, multidomain RNA polymerase (RNAP) trigger reversible conformational changes at pause sites that temporarily interrupt the nucleotide addition cycle. These interactions initially rearrange the elongation complex (EC) into an elemental paused EC (ePEC). ePECs can form longer-lived PECs by further rearrangements or interactions of diffusible regulators. For both bacterial and mammalian RNAPs, a half-translocated state in which the next DNA template base fails to load into the active site appears central to the ePEC. Some RNAPs also swivel interconnected modules that may stabilize the ePEC. However, it is unclear whether swiveling and half-translocation are requisite features of a single ePEC state or if multiple ePEC states exist. Here, we use cryo-electron microscopy (cryo-EM) analysis of ePECs with different RNA-DNA sequences combined with biochemical probes of ePEC structure to define an interconverting ensemble of ePEC states. ePECs occupy either pre- or half-translocated states but do not always swivel, indicating that difficulty in forming the posttranslocated state at certain RNA-DNA sequences may be the essence of the ePEC. The existence of multiple ePEC conformations has broad implications for transcriptional regulation.
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Affiliation(s)
- Jin Young Kang
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon34141, Republic of Korea
| | - Tatiana V. Mishanina
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA92093
| | - Yu Bao
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI53706
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - Eliza Llewellyn
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - James Liu
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI53706
| | - Seth A. Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI53706
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI53706
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11
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Nabavizadeh N, Bressin A, Shboul M, Moreno Traspas R, Chia PH, Bonnard C, Szenker‐Ravi E, Sarıbaş B, Beillard E, Altunoglu U, Hojati Z, Drutman S, Freier S, El‐Khateeb M, Fathallah R, Casanova J, Soror W, Arafat A, Escande‐Beillard N, Mayer A, Reversade B. A progeroid syndrome caused by a deep intronic variant in TAPT1 is revealed by RNA/SI-NET sequencing. EMBO Mol Med 2023; 15:e16478. [PMID: 36652330 PMCID: PMC9906387 DOI: 10.15252/emmm.202216478] [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: 06/21/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 01/19/2023] Open
Abstract
Exome sequencing has introduced a paradigm shift for the identification of germline variations responsible for Mendelian diseases. However, non-coding regions, which make up 98% of the genome, cannot be captured. The lack of functional annotation for intronic and intergenic variants makes RNA-seq a powerful companion diagnostic. Here, we illustrate this point by identifying six patients with a recessive Osteogenesis Imperfecta (OI) and neonatal progeria syndrome. By integrating homozygosity mapping and RNA-seq, we delineated a deep intronic TAPT1 mutation (c.1237-52 G>A) that segregated with the disease. Using SI-NET-seq, we document that TAPT1's nascent transcription was not affected in patients' fibroblasts, indicating instead that this variant leads to an alteration of pre-mRNA processing. Predicted to serve as an alternative splicing branchpoint, this mutation enhances TAPT1 exon 12 skipping, creating a protein-null allele. Additionally, our study reveals dysregulation of pathways involved in collagen and extracellular matrix biology in disease-relevant cells. Overall, our work highlights the power of transcriptomic approaches in deciphering the repercussions of non-coding variants, as well as in illuminating the molecular mechanisms of human diseases.
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Affiliation(s)
- Nasrinsadat Nabavizadeh
- Laboratory of Human Genetics & TherapeuticsGenome Institute of Singapore, A*STARSingapore CitySingapore
- Division of Genetics, Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and TechnologyUniversity of IsfahanIsfahanIran
- Medical Genetics DepartmentKoç University School of MedicineIstanbulTurkey
| | | | - Mohammad Shboul
- Department of Medical Laboratory SciencesJordan University of Science and TechnologyIrbidJordan
| | - Ricardo Moreno Traspas
- Laboratory of Human Genetics & TherapeuticsGenome Institute of Singapore, A*STARSingapore CitySingapore
| | - Poh Hui Chia
- Laboratory of Human Genetics & TherapeuticsGenome Institute of Singapore, A*STARSingapore CitySingapore
| | - Carine Bonnard
- Model Development, A*STAR Skin Research Labs (A*SRL)Singapore CitySingapore
| | - Emmanuelle Szenker‐Ravi
- Laboratory of Human Genetics & TherapeuticsGenome Institute of Singapore, A*STARSingapore CitySingapore
| | - Burak Sarıbaş
- Laboratory of Human Genetics & TherapeuticsGenome Institute of Singapore, A*STARSingapore CitySingapore
- Medical Genetics DepartmentKoç University School of MedicineIstanbulTurkey
| | | | - Umut Altunoglu
- Medical Genetics DepartmentKoç University School of MedicineIstanbulTurkey
| | - Zohreh Hojati
- Division of Genetics, Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and TechnologyUniversity of IsfahanIsfahanIran
| | - Scott Drutman
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller BranchRockefeller UniversityNew YorkNYUSA
| | - Susanne Freier
- Max Planck Institute for Molecular GeneticsBerlinGermany
| | | | - Rajaa Fathallah
- National Center for Diabetes, Endocrinology and GeneticsAmmanJordan
| | - Jean‐Laurent Casanova
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller BranchRockefeller UniversityNew YorkNYUSA
- Laboratory of Human Genetics of Infectious Diseases, Necker BranchINSERM U1163, Necker Hospital for Sick ChildrenParisFrance
- Imagine InstituteUniversity of ParisParisFrance
- Howard Hughes Medical InstituteNew YorkNYUSA
- Pediatric Hematology and Immunology UnitNecker Hospital for Sick ChildrenParisFrance
| | - Wesam Soror
- National Center for Diabetes, Endocrinology and GeneticsAmmanJordan
| | - Alaa Arafat
- National Center for Diabetes, Endocrinology and GeneticsAmmanJordan
| | - Nathalie Escande‐Beillard
- Medical Genetics DepartmentKoç University School of MedicineIstanbulTurkey
- Institute of Molecular and Cell Biology, A*STARSingapore CitySingapore
| | - Andreas Mayer
- Max Planck Institute for Molecular GeneticsBerlinGermany
| | - Bruno Reversade
- Laboratory of Human Genetics & TherapeuticsGenome Institute of Singapore, A*STARSingapore CitySingapore
- Medical Genetics DepartmentKoç University School of MedicineIstanbulTurkey
- Institute of Molecular and Cell Biology, A*STARSingapore CitySingapore
- Department of PaediatricsNational University of SingaporeSingapore CitySingapore
- Smart‐Health Initiative, BESE, KAUSTThuwalKingdom of Saudi Arabia
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12
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Eischer N, Arnold M, Mayer A. Emerging roles of BET proteins in transcription and co-transcriptional RNA processing. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1734. [PMID: 35491403 DOI: 10.1002/wrna.1734] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/06/2022] [Accepted: 04/09/2022] [Indexed: 01/31/2023]
Abstract
Transcription by RNA polymerase II (Pol II) gives rise to all nuclear protein-coding and a large set of non-coding RNAs, and is strictly regulated and coordinated with RNA processing. Bromodomain and extraterminal (BET) family proteins including BRD2, BRD3, and BRD4 have been implicated in the regulation of Pol II transcription in mammalian cells. However, only recent technological advances have allowed the analysis of direct functions of individual BET proteins with high precision in cells. These studies shed new light on the molecular mechanisms of transcription control by BET proteins challenging previous longstanding views. The most studied BET protein, BRD4, emerges as a master regulator of transcription elongation with roles also in coupling nascent transcription with RNA processing. In contrast, BRD2 is globally required for the formation of transcriptional boundaries to restrict enhancer activity to nearby genes. Although these recent findings suggest non-redundant functions of BRD4 and BRD2 in Pol II transcription, more research is needed for further clarification. Little is known about the roles of BRD3. Here, we illuminate experimental work that has initially linked BET proteins to Pol II transcription in mammalian cells, outline main methodological breakthroughs that have strongly advanced the understanding of BET protein functions, and discuss emerging roles of individual BET proteins in transcription and transcription-coupled RNA processing. Finally, we propose an updated model for the function of BRD4 in transcription and co-transcriptional RNA maturation. This article is categorized under: RNA Processing > 3' End Processing RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
- Nicole Eischer
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Mirjam Arnold
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Andreas Mayer
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany
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13
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Huffines AK, Engel KL, French SL, Zhang Y, Viktorovskaya OV, Schneider DA. Rate of transcription elongation and sequence-specific pausing by RNA polymerase I directly influence rRNA processing. J Biol Chem 2022; 298:102730. [PMID: 36423683 PMCID: PMC9768379 DOI: 10.1016/j.jbc.2022.102730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/18/2022] [Accepted: 11/07/2022] [Indexed: 11/23/2022] Open
Abstract
One of the first steps in ribosome biogenesis is transcription of the ribosomal DNA by RNA polymerase I (Pol I). Processing of the resultant rRNA begins cotranscriptionally, and perturbation of Pol I transcription elongation results in defective rRNA processing. Mechanistic insight regarding the link between transcription elongation and ribosome assembly is lacking because of limited in vivo methods to assay Pol I transcription. Here, we use native elongating transcript sequencing (NET-Seq) with a strain of Saccharomyces cerevisiae containing a point mutation in Pol I, rpa190-F1205H, which results in impaired rRNA processing and ribosome assembly. We previously demonstrated that this mutation caused a mild reduction in the transcription elongation rate of Pol I in vitro; however, transcription elongation by the mutant has not been characterized in vivo. Here, our findings demonstrate that the mutant Pol I has an increased pause propensity during processive transcription elongation both in vitro and in vivo. NET-Seq reveals that rpa190-F1205H Pol I displays alternative pause site preferences in vivo. Specifically, the mutant is sensitized to A/G residues in the RNA:DNA hybrid and at the last incorporated nucleotide position. Furthermore, both NET-Seq and EM analysis of Miller chromatin spreads reveal pileups of rpa190-F1205H Pol I throughout the ribosomal DNA, particularly at the 5' end of the 35S gene. This combination of in vitro and in vivo analyses of a Pol I mutant provides novel insights into Pol I elongation properties and indicates how these properties are crucial for efficient cotranscriptional rRNA processing and ribosome assembly.
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Affiliation(s)
- Abigail K Huffines
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Krysta L Engel
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Sarah L French
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Yinfeng Zhang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Olga V Viktorovskaya
- 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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14
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Jiang Y, Huang J, Tian K, Yi X, Zheng H, Zhu Y, Guo T, Ji X. Cross-regulome profiling of RNA polymerases highlights the regulatory role of polymerase III on mRNA transcription by maintaining local chromatin architecture. Genome Biol 2022; 23:246. [PMID: 36443871 PMCID: PMC9703767 DOI: 10.1186/s13059-022-02812-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 11/07/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Mammalian cells have three types of RNA polymerases (Pols), Pol I, II, and III. However, the extent to which these polymerases are cross-regulated and the underlying mechanisms remain unclear. RESULTS We employ genome-wide profiling after acute depletion of Pol I, Pol II, or Pol III to assess cross-regulatory effects between these Pols. We find that these enzymes mainly affect the transcription of their own target genes, while certain genes are transcribed by the other polymerases. Importantly, the most active type of crosstalk is exemplified by the fact that Pol III depletion affects Pol II transcription. Pol II genes with transcription changes upon Pol III depletion are enriched in diverse cellular functions, and Pol III binding sites are found near their promoters. However, these Pol III binding sites do not correspond to transfer RNAs. Moreover, we demonstrate that Pol III regulates Pol II transcription and chromatin binding of the facilitates chromatin transcription (FACT) complex to alter local chromatin structures, which in turn affects the Pol II transcription rate. CONCLUSIONS Our results support a model suggesting that RNA polymerases show cross-regulatory effects: Pol III affects local chromatin structures and the FACT-Pol II axis to regulate the Pol II transcription rate at certain gene loci. This study provides a new perspective for understanding the dysregulation of Pol III in various tissues affected by developmental diseases.
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Affiliation(s)
- Yongpeng Jiang
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Jie Huang
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Kai Tian
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Xiao Yi
- grid.494629.40000 0004 8008 9315Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,grid.494629.40000 0004 8008 9315Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,Westlake Omics (Hangzhou) Biotechnology Co., Ltd, Hangzhou, 310024 China
| | - Haonan Zheng
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
| | - Yi Zhu
- grid.494629.40000 0004 8008 9315Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,grid.494629.40000 0004 8008 9315Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,Westlake Omics (Hangzhou) Biotechnology Co., Ltd, Hangzhou, 310024 China
| | - Tiannan Guo
- grid.494629.40000 0004 8008 9315Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,grid.494629.40000 0004 8008 9315Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024 Zhejiang Province China ,Westlake Omics (Hangzhou) Biotechnology Co., Ltd, Hangzhou, 310024 China
| | - Xiong Ji
- grid.452723.50000 0004 7887 9190Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871 China
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15
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Fong N, Sheridan RM, Ramachandran S, Bentley DL. The pausing zone and control of RNA polymerase II elongation by Spt5: Implications for the pause-release model. Mol Cell 2022; 82:3632-3645.e4. [PMID: 36206739 PMCID: PMC9555879 DOI: 10.1016/j.molcel.2022.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/24/2022] [Accepted: 08/31/2022] [Indexed: 11/07/2022]
Abstract
The pause-release model of transcription proposes that 40-100 bases from the start site RNA Pol II pauses, followed by release into productive elongation. Pause release is facilitated by the PTEFb phosphorylation of the RNA Pol II elongation factor, Spt5. We mapped paused polymerases by eNET-seq and found frequent pausing in zones that extend ∼0.3-3 kb into genes even when PTEFb is inhibited. The fraction of paused polymerases or pausing propensity declines gradually over several kb and not abruptly as predicted for a discrete pause-release event. Spt5 depletion extends pausing zones, suggesting that it promotes the maturation of elongation complexes to a low-pausing state. The expression of mutants after Spt5 depletion showed that phosphomimetic substitutions in the CTR1 domain diminished pausing throughout genes. By contrast, mutants that prevent the phosphorylation of the Spt5 RNA-binding domain strengthened pausing. Thus, distinct Spt5 phospho-isoforms set the balance between pausing and elongation.
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Affiliation(s)
- Nova Fong
- RNA Bioscience Initiative, Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - Ryan M Sheridan
- RNA Bioscience Initiative, Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - Srinivas Ramachandran
- RNA Bioscience Initiative, Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - David L Bentley
- RNA Bioscience Initiative, Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA.
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16
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Abstract
Transcription elongation by RNA polymerase II (Pol II) has emerged as a regulatory hub in gene expression. A key control point occurs during early transcription elongation when Pol II pauses in the promoter-proximal region at the majority of genes in mammalian cells and at a large set of genes in Drosophila. An increasing number of trans-acting factors have been linked to promoter-proximal pausing. Some factors help to establish the pause, whereas others are required for the release of Pol II into productive elongation. A dysfunction of this elongation control point leads to aberrant gene expression and can contribute to disease development. The BET bromodomain protein BRD4 has been implicated in elongation control. However, only recently direct BRD4-specific functions in Pol II transcription elongation have been uncovered. This mainly became possible with technological advances that allow selective and rapid ablation of BRD4 in cells along with the availability of approaches that capture the immediate consequences on nascent transcription. This review sheds light on the experimental breakthroughs that led to the emerging view of BRD4 as a general regulator of transcription elongation.
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Affiliation(s)
- Elisabeth Altendorfer
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Yelizaveta Mochalova
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany.,Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Andreas Mayer
- Otto-Warburg-Laboratory, Max Planck Institute for Molecular Genetics, Berlin, Germany
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17
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Couvillion M, Harlen KM, Lachance KC, Trotta KL, Smith E, Brion C, Smalec BM, Churchman LS. Transcription elongation is finely tuned by dozens of regulatory factors. eLife 2022; 11:e78944. [PMID: 35575476 PMCID: PMC9154744 DOI: 10.7554/elife.78944] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/15/2022] [Indexed: 11/30/2022] Open
Abstract
Understanding the complex network that regulates transcription elongation requires the quantitative analysis of RNA polymerase II (Pol II) activity in a wide variety of regulatory environments. We performed native elongating transcript sequencing (NET-seq) in 41 strains of Saccharomyces cerevisiae lacking known elongation regulators, including RNA processing factors, transcription elongation factors, chromatin modifiers, and remodelers. We found that the opposing effects of these factors balance transcription elongation and antisense transcription. Different sets of factors tightly regulate Pol II progression across gene bodies so that Pol II density peaks at key points of RNA processing. These regulators control where Pol II pauses with each obscuring large numbers of potential pause sites that are primarily determined by DNA sequence and shape. Antisense transcription varies highly across the regulatory landscapes analyzed, but antisense transcription in itself does not affect sense transcription at the same locus. Our findings collectively show that a diverse array of factors regulate transcription elongation by precisely balancing Pol II activity.
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Affiliation(s)
- Mary Couvillion
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Kevin M Harlen
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Kate C Lachance
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Kristine L Trotta
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Erin Smith
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Christian Brion
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Brendan M Smalec
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - L Stirling Churchman
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
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18
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Jeronimo C, Robert F. The histone chaperone FACT: a guardian of chromatin structure integrity. Transcription 2022; 13:16-38. [PMID: 35485711 PMCID: PMC9467567 DOI: 10.1080/21541264.2022.2069995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The identification of FACT as a histone chaperone enabling transcription through chromatin in vitro has strongly shaped how its roles are envisioned. However, FACT has been implicated in essentially all aspects of chromatin biology, from transcription to DNA replication, DNA repair, and chromosome segregation. In this review, we focus on recent literature describing the role and mechanisms of FACT during transcription. We highlight the prime importance of FACT in preserving chromatin integrity during transcription and challenge its role as an elongation factor. We also review evidence for FACT's role as a cell-type/gene-specificregulator of gene expression and briefly summarize current efforts at using FACT inhibition as an anti-cancerstrategy.
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Affiliation(s)
- Célia Jeronimo
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, Montréal, Québec, Canada.,Département de Médecine, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada.,Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec, Canada
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19
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Xu Z, Zhang N, Fu H, Wang F, Wen M, Chang H, Wu J, Abdelaala WB, Luo Q, Li Y, Li C, Wang Q, Wang ZY. Salt Stress Modulates the Landscape of Transcriptome and Alternative Splicing in Date Palm ( Phoenix dactylifera L.). FRONTIERS IN PLANT SCIENCE 2022; 12:807739. [PMID: 35126432 PMCID: PMC8810534 DOI: 10.3389/fpls.2021.807739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/20/2021] [Indexed: 05/14/2023]
Abstract
Date palm regards as a valuable genomic resource for exploring the tolerance genes due to its ability to survive under the sever condition. Although a large number of differentiated genes were identified in date palm responding to salt stress, the genome-wide study of alternative splicing (AS) landscape under salt stress conditions remains unknown. In the current study, we identified the stress-related genes through transcriptomic analysis to characterize their function under salt. A total of 17,169 genes were differentially expressed under salt stress conditions. Gene expression analysis confirmed that the salt overly sensitive (SOS) pathway genes, such as PdSOS2;1, PdSOS2;2, PdSOS4, PdSOS5, and PdCIPK11 were involved in the regulation of salt response in date palm, which is consistent with the physiological analysis that high salinity affected the Na+/K+ homeostasis and amino acid profile of date palm resulted in the inhibition of plant growth. Interestingly, the pathway of "spliceosome" was enriched in the category of upregulation, indicating their potential role of AS in date palm response to salt stress. Expectedly, many differentially alternative splicing (DAS) events were found under salt stress conditions, and some splicing factors, such as PdRS40, PdRSZ21, PdSR45a, and PdU2Af genes were abnormally spliced under salt, suggesting that AS-related proteins might participated in regulating the salt stress pathway. Moreover, the number of differentially DAS-specific genes was gradually decreased, while the number of differentially expressed gene (DEG)-specific genes was increased with prolonged salt stress treatment, suggesting that AS and gene expression could be distinctively regulated in response to salt stress. Therefore, our study highlighted the pivotal role of AS in the regulation of salt stress and provided novel insights for enhancing the resistance to salt in date palm.
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Affiliation(s)
- Zhongliang Xu
- Sanya Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
| | - Ning Zhang
- Sanya Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
| | - Haiquan Fu
- Sanya Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
| | - Fuyou Wang
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
| | - Mingfu Wen
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
- Zhanjiang Sugarcane Research Center, Guangzhou Sugarcane Industry Research Institute, Guangzhou, China
| | - Hailong Chang
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
| | - Jiantao Wu
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
| | - Walid Badawy Abdelaala
- Coconut Research Institute, Chinese Academy of Tropical Agricultural Sciences, Hainan, China
- Central Laboratory for Date Palm Research and Development of Agriculture Research Center, Giza, Egypt
| | - Qingwen Luo
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
- Zhanjiang Sugarcane Research Center, Guangzhou Sugarcane Industry Research Institute, Guangzhou, China
| | - Yang Li
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
- Zhanjiang Sugarcane Research Center, Guangzhou Sugarcane Industry Research Institute, Guangzhou, China
| | - Cong Li
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
- Zhanjiang Sugarcane Research Center, Guangzhou Sugarcane Industry Research Institute, Guangzhou, China
| | - Qinnan Wang
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
| | - Zhen-Yu Wang
- Institute of Nanfan & Seed Industry, Guangdong Academy of Sciences, Zhanjiang, China
- Zhanjiang Sugarcane Research Center, Guangzhou Sugarcane Industry Research Institute, Guangzhou, China
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20
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Palo MZ, Zhu J, Mishanina TV, Landick R. Conserved Trigger Loop Histidine of RNA Polymerase II Functions as a Positional Catalyst Primarily through Steric Effects. Biochemistry 2021; 60:3323-3336. [PMID: 34705427 DOI: 10.1021/acs.biochem.1c00528] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In all domains of life, multisubunit RNA polymerases (RNAPs) catalyze both the extension of mRNA transcripts by nucleotide addition and the hydrolysis of RNA, which enables proofreading by removal of misincorporated nucleotides. A highly conserved catalytic module within RNAPs called the trigger loop (TL) functions as the key controller of these activities. The TL is proposed to act as a positional catalyst of phosphoryl transfer and transcript cleavage via electrostatic and steric contacts with substrates in its folded helical form. The function of a near-universally conserved TL histidine that contacts NTP phosphates is of particular interest. Despite its exceptional conservation, substitutions of the TL His with Gln support efficient catalysis in bacterial and yeast RNAPs. Unlike bacterial TLs, which contain a nearby Arg, the TL His is the only acid-base catalyst candidate in the eukaryotic RNAPII TL. Nonetheless, replacement of the TL His with Leu is reported to support cell growth in yeast, suggesting that even hydrogen bonding and polarity at this position may be dispensable for efficient catalysis by RNAPII. To test how a TL His-to-Leu substitution affects the enzymatic functions of RNAPII, we compared its rates of nucleotide addition, pyrophosphorolysis, and RNA hydrolysis to those of the wild-type RNAPII enzyme. The His-to-Leu substitution slightly reduced rates of phosphoryl transfer with little if any effect on intrinsic transcript cleavage. These findings indicate that the highly conserved TL His is neither an obligate acid-base catalyst nor a polar contact for NTP phosphates but instead functions as a positional catalyst mainly through steric effects.
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Affiliation(s)
- Michael Z Palo
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Junqiao Zhu
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Tatiana V Mishanina
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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21
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Abstract
Cellular life depends on transcription of DNA by RNA polymerase to express genetic information. RNA polymerase has evolved not just to read information from DNA and write it to RNA but also to sense and process information from the cellular and extracellular environments. Much of this information processing occurs during transcript elongation, when transcriptional pausing enables regulatory decisions. Transcriptional pauses halt RNA polymerase in response to DNA and RNA sequences and structures at locations and times that help coordinate interactions with small molecules and transcription factors important for regulation. Four classes of transcriptional pause signals are now evident after decades of study: elemental pauses, backtrack pauses, hairpin-stabilized pauses, and regulator-stabilized pauses. In this review, I describe current understanding of the molecular mechanisms of these four classes of pause signals, remaining questions about how RNA polymerase responds to pause signals, and the many exciting directions now open to understand pausing and the regulation of transcript elongation on a genome-wide scale. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Robert Landick
- Department of Biochemistry and Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA;
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22
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A BRD4-mediated elongation control point primes transcribing RNA polymerase II for 3'-processing and termination. Mol Cell 2021; 81:3589-3603.e13. [PMID: 34324863 DOI: 10.1016/j.molcel.2021.06.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 04/14/2021] [Accepted: 06/22/2021] [Indexed: 12/15/2022]
Abstract
Transcription elongation has emerged as a regulatory hub in gene expression of metazoans. A major control point occurs during early elongation before RNA polymerase II (Pol II) is released into productive elongation. Prior research has linked BRD4 with transcription elongation. Here, we use rapid BET protein and BRD4-selective degradation along with quantitative genome-wide approaches to investigate direct functions of BRD4 in Pol II transcription regulation. Notably, as an immediate consequence of acute BRD4 loss, promoter-proximal pause release is impaired, and transcriptionally engaged Pol II past this checkpoint undergoes readthrough transcription. An integrated proteome-wide analysis uncovers elongation and 3'-RNA processing factors as core BRD4 interactors. BRD4 ablation disrupts the recruitment of general 3'-RNA processing factors at the 5'-control region, which correlates with RNA cleavage and termination defects. These studies, performed in human cells, reveal a BRD4-mediated checkpoint and begin to establish a molecular link between 5'-elongation control and 3'-RNA processing.
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