1
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Hyder U, Challa A, Thornton M, Nandu T, Kraus WL, D'Orso I. KAP1 negatively regulates RNA polymerase II elongation kinetics to activate signal-induced transcription. Nat Commun 2024; 15:5859. [PMID: 38997286 PMCID: PMC11245487 DOI: 10.1038/s41467-024-49905-7] [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: 11/05/2023] [Accepted: 06/20/2024] [Indexed: 07/14/2024] Open
Abstract
Signal-induced transcriptional programs regulate critical biological processes through the precise spatiotemporal activation of Immediate Early Genes (IEGs); however, the mechanisms of transcription induction remain poorly understood. By combining an acute depletion system with several genomics approaches to interrogate synchronized, temporal transcription, we reveal that KAP1/TRIM28 is a first responder that fulfills the temporal and heightened transcriptional demand of IEGs. Acute KAP1 loss triggers an increase in RNA polymerase II elongation kinetics during early stimulation time points. This elongation defect derails the normal progression through the transcriptional cycle during late stimulation time points, ultimately leading to decreased recruitment of the transcription apparatus for re-initiation thereby dampening IEGs transcriptional output. Collectively, KAP1 plays a counterintuitive role by negatively regulating transcription elongation to support full activation across multiple transcription cycles of genes critical for cell physiology and organismal functions.
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Affiliation(s)
- Usman Hyder
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ashwini Challa
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Micah Thornton
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Tulip Nandu
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - W Lee Kraus
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Iván D'Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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2
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Ma M, Szavits-Nossan J, Singh A, Grima R. Analysis of a detailed multi-stage model of stochastic gene expression using queueing theory and model reduction. Math Biosci 2024; 373:109204. [PMID: 38710441 DOI: 10.1016/j.mbs.2024.109204] [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: 01/23/2024] [Revised: 04/03/2024] [Accepted: 04/29/2024] [Indexed: 05/08/2024]
Abstract
We introduce a biologically detailed, stochastic model of gene expression describing the multiple rate-limiting steps of transcription, nuclear pre-mRNA processing, nuclear mRNA export, cytoplasmic mRNA degradation and translation of mRNA into protein. The processes in sub-cellular compartments are described by an arbitrary number of processing stages, thus accounting for a significantly finer molecular description of gene expression than conventional models such as the telegraph, two-stage and three-stage models of gene expression. We use two distinct tools, queueing theory and model reduction using the slow-scale linear-noise approximation, to derive exact or approximate analytic expressions for the moments or distributions of nuclear mRNA, cytoplasmic mRNA and protein fluctuations, as well as lower bounds for their Fano factors in steady-state conditions. We use these to study the phase diagram of the stochastic model; in particular we derive parametric conditions determining three types of transitions in the properties of mRNA fluctuations: from sub-Poissonian to super-Poissonian noise, from high noise in the nucleus to high noise in the cytoplasm, and from a monotonic increase to a monotonic decrease of the Fano factor with the number of processing stages. In contrast, protein fluctuations are always super-Poissonian and show weak dependence on the number of mRNA processing stages. Our results delineate the region of parameter space where conventional models give qualitatively incorrect results and provide insight into how the number of processing stages, e.g. the number of rate-limiting steps in initiation, splicing and mRNA degradation, shape stochastic gene expression by modulation of molecular memory.
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Affiliation(s)
- Muhan Ma
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | | | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark DE 19716, USA
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK.
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3
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Mayeux F, Buisine N, Fayol O, Uguen P. Transcriptional activation of candidate paused genes after partial hepatectomy. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001160. [PMID: 38919542 PMCID: PMC11196992 DOI: 10.17912/micropub.biology.001160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/26/2024] [Accepted: 05/31/2024] [Indexed: 06/27/2024]
Abstract
Partial hepatectomy is a model of acute liver injury that is known to induce a strong reprogrammation of gene expression. Transcriptional induction of Immediate Early Genes is extremely fast and this would be due to the release of RNA Polymerase II poised for elongation at 'paused' genes. Using bioinformatic analysis, we identified 23 genes sharing features of paused genes before hepatectomy, and with predicted quick and strong expression induction after. This transcriptional dynamic, confirmed by RT-qPCR for Jun , Fos , Btg2, is very precocious. RNA Pol II CTD Ser2 hyperphosphorylation indicates a switch to productive elongation and release from transcriptional pause.
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Affiliation(s)
| | - Nicolas Buisine
- UMR CNRS 7221, Muséum national d'Histoire naturelle, Paris, France
| | | | - Patricia Uguen
- UMR-S1174, Université Paris-Saclay, Orsay, France
- UMR 3348, INSERM U1278, Institut Curie, Université Paris-Saclay, Orsay, France
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4
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Hyder U, Challa A, Thornton M, Nandu T, Kraus WL, D’Orso I. KAP1 negatively regulates RNA polymerase II elongation kinetics to activate signal-induced transcription. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.05.592422. [PMID: 38746145 PMCID: PMC11092767 DOI: 10.1101/2024.05.05.592422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Signal-induced transcriptional programs regulate critical biological processes through the precise spatiotemporal activation of Immediate Early Genes (IEGs); however, the mechanisms of transcription induction remain poorly understood. By combining an acute depletion system with high resolution genomics approaches to interrogate synchronized, temporal transcription, we reveal that KAP1/TRIM28 is a first responder that fulfills the temporal and heightened transcriptional demand of IEGs. Unexpectedly, acute KAP1 loss triggers an increase in RNA polymerase II elongation kinetics during early stimulation time points. This elongation defect derails the normal progression through the transcriptional cycle during late stimulation time points, ultimately leading to decreased recruitment of the transcription apparatus for re-initiation thereby dampening IEGs transcriptional output. Collectively, KAP1 plays a counterintuitive role by negatively regulating transcription elongation to support full activation across multiple transcription cycles of genes critical for cell physiology and organismal functions.
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Affiliation(s)
- Usman Hyder
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ashwini Challa
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Micah Thornton
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tulip Nandu
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - W. Lee Kraus
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Iván D’Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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5
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Jones T, Sigauke RF, Sanford L, Taatjes DJ, Allen MA, Dowell RD. A transcription factor (TF) inference method that broadly measures TF activity and identifies mechanistically distinct TF networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.15.585303. [PMID: 38559193 PMCID: PMC10980006 DOI: 10.1101/2024.03.15.585303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
TF profiler is a method of inferring transcription factor regulatory activity, i.e. when a TF is present and actively regulating transcription, directly directly from nascent sequencing assays such as PRO-seq and GRO-seq. Transcription factors orchestrate transcription and play a critical role in cellular maintenance, identity and response to external stimuli. While ChIP assays have measured DNA localization, they fall short of identifying when and where transcription factors are actively regulating transcription. Our method, on the other hand, uses RNA polymerase activity to infer TF activity across hundreds of data sets and transcription factors. Based on these classifications we identify three distinct classes of transcription factors: ubiquitous factors that play roles in cellular homeostasis, driving basal gene programs across tissues and cell types, tissue specific factors that act almost exclusively at enhancers and are themselves regulated at transcription, and stimulus responsive TFs which are regulated post-transcriptionally but act predominantly at enhancers. TF profiler is broadly applicable, providing regulatory insights on any PRO-seq sample for any transcription factor with a known binding motif.
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6
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Dunn LEM, Birkenheuer CH, Baines JD. A Revision of Herpes Simplex Virus Type 1 Transcription: First, Repress; Then, Express. Microorganisms 2024; 12:262. [PMID: 38399666 PMCID: PMC10892140 DOI: 10.3390/microorganisms12020262] [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: 12/15/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The herpes virus genome bears more than 80 strong transcriptional promoters. Upon entry into the host cell nucleus, these genes are transcribed in an orderly manner, producing five immediate-early (IE) gene products, including ICP0, ICP4, and ICP22, while non-IE genes are mostly silent. The IE gene products are necessary for the transcription of temporal classes following sequentially as early, leaky late, and true late. A recent analysis using precision nuclear run-on followed by deep sequencing (PRO-seq) has revealed an important step preceding all HSV-1 transcription. Specifically, the immediate-early proteins ICP4 and ICP0 enter the cell with the incoming genome to help preclude the nascent antisense, intergenic, and sense transcription of all viral genes. VP16, which is also delivered into the nucleus upon entry, almost immediately reverses this repression on IE genes. The resulting de novo expression of ICP4 and ICP22 further repress antisense, intergenic, and early and late viral gene transcription through different mechanisms before the sequential de-repression of these gene classes later in infection. This early repression, termed transient immediate-early protein-mediated repression (TIEMR), precludes unproductive, antisense, intergenic, and late gene transcription early in infection to ensure the efficient and orderly progression of the viral cascade.
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Affiliation(s)
- Laura E M Dunn
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
| | - Claire H Birkenheuer
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
| | - Joel D Baines
- Baker Institute for Animal Health, Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14850, USA
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7
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Sigauke RF, Sanford L, Maas ZL, Jones T, Stanley JT, Townsend HA, Allen MA, Dowell RD. Atlas of nascent RNA transcripts reveals enhancer to gene linkages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.07.570626. [PMID: 38105978 PMCID: PMC10723487 DOI: 10.1101/2023.12.07.570626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Gene transcription is controlled and modulated by regulatory regions, including enhancers and promoters. These regions are abundant in unstable, non-coding bidirectional transcription. Using nascent RNA transcription data across hundreds of human samples, we identified over 800,000 regions containing bidirectional transcription. We then identify highly correlated transcription between bidirectional and gene regions. The identified correlated pairs, a bidirectional region and a gene, are enriched for disease associated SNPs and often supported by independent 3D data. We present these resources as an SQL database which serves as a resource for future studies into gene regulation, enhancer associated RNAs, and transcription factors.
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Affiliation(s)
- Rutendo F. Sigauke
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
| | - Lynn Sanford
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
| | - Zachary L. Maas
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
- Computer Science, University of Colorado Boulder, 1111 Engineering Drive, UCB 430, Boulder, 80309, CO, USA
| | - Taylor Jones
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
| | - Jacob T. Stanley
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
| | - Hope A. Townsend
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
- Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave, UCB 347, Boulder, 80309, CO, USA
| | - Mary A. Allen
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
| | - Robin D. Dowell
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave., UCB 596, Boulder, 80309, CO, USA
- Computer Science, University of Colorado Boulder, 1111 Engineering Drive, UCB 430, Boulder, 80309, CO, USA
- Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Ave, UCB 347, Boulder, 80309, CO, USA
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8
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Dastidar SG, De Kumar B, Lauckner B, Parrello D, Perley D, Vlasenok M, Tyagi A, Koney NKK, Abbas A, Nechaev S. Transcriptional responses of cancer cells to heat shock-inducing stimuli involve amplification of robust HSF1 binding. Nat Commun 2023; 14:7420. [PMID: 37973875 PMCID: PMC10654513 DOI: 10.1038/s41467-023-43157-7] [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: 11/23/2022] [Accepted: 11/01/2023] [Indexed: 11/19/2023] Open
Abstract
Responses of cells to stimuli are increasingly discovered to involve the binding of sequence-specific transcription factors outside of known target genes. We wanted to determine to what extent the genome-wide binding and function of a transcription factor are shaped by the cell type versus the stimulus. To do so, we induced the Heat Shock Response pathway in two different cancer cell lines with two different stimuli and related the binding of its master regulator HSF1 to nascent RNA and chromatin accessibility. Here, we show that HSF1 binding patterns retain their identity between basal conditions and under different magnitudes of activation, so that common HSF1 binding is globally associated with distinct transcription outcomes. HSF1-induced increase in DNA accessibility was modest in scale, but occurred predominantly at remote genomic sites. Apart from regulating transcription at existing elements including promoters and enhancers, HSF1 binding amplified during responses to stimuli may engage inactive chromatin.
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Affiliation(s)
- Sayantani Ghosh Dastidar
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
- Illumina, Inc., San Diego, CA, 92122, USA
| | - Bony De Kumar
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
- Yale Center for Genome Analysis, Department of Genetics, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Bo Lauckner
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
| | - Damien Parrello
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
| | - Danielle Perley
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
- Canadian Centre for Computational Genomics, McGill Genome Centre, Montreal, QC, H3A0G1, Canada
| | - Maria Vlasenok
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, 121205, Russia
| | - Antariksh Tyagi
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
- Yale Center for Genome Analysis, Department of Genetics, Yale University School of Medicine, New Haven, CT, 06510, USA
| | - Nii Koney-Kwaku Koney
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
- University of Ghana Medical School, University of Ghana, Accra, Ghana
| | - Ata Abbas
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Sergei Nechaev
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, 58202, USA.
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9
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Hunter S, Hendrix J, Freeman J, Dowell RD, Allen MA. Transcription dosage compensation does not occur in Down syndrome. BMC Biol 2023; 21:228. [PMID: 37946204 PMCID: PMC10636926 DOI: 10.1186/s12915-023-01700-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 09/12/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND The increase in DNA copy number in Down syndrome (DS; caused by trisomy 21) has led to the DNA dosage hypothesis, which posits that the level of gene expression is proportional to the gene's DNA copy number. Yet many reports have suggested that a proportion of chromosome 21 genes are dosage compensated back towards typical expression levels (1.0×). In contrast, other reports suggest that dosage compensation is not a common mechanism of gene regulation in trisomy 21, providing support to the DNA dosage hypothesis. RESULTS In our work, we use both simulated and real data to dissect the elements of differential expression analysis that can lead to the appearance of dosage compensation, even when compensation is demonstrably absent. Using lymphoblastoid cell lines derived from a family with an individual with Down syndrome, we demonstrate that dosage compensation is nearly absent at both nascent transcription (GRO-seq) and steady-state RNA (RNA-seq) levels. Furthermore, we link the limited apparent dosage compensation to expected allelic variation in transcription levels. CONCLUSIONS Transcription dosage compensation does not occur in Down syndrome. Simulated data containing no dosage compensation can appear to have dosage compensation when analyzed via standard methods. Moreover, some chromosome 21 genes that appear to be dosage compensated are consistent with allele specific expression.
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Affiliation(s)
- Samuel Hunter
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, 80301, USA
| | - Jo Hendrix
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
- Computational Bioscience, The University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Justin Freeman
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
| | - Robin D Dowell
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, 80301, USA
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
- Linda Crnic Institute for Down Syndrome, 80045, Aurora, USA
- Crnic Boulder Branch, BioFrontiers, Boulder, 80309, USA
| | - Mary A Allen
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA.
- Linda Crnic Institute for Down Syndrome, 80045, Aurora, USA.
- Crnic Boulder Branch, BioFrontiers, Boulder, 80309, USA.
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10
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Martell DJ, Merens HE, Caulier A, Fiorini C, Ulirsch JC, Ietswaart R, Choquet K, Graziadei G, Brancaleoni V, Cappellini MD, Scott C, Roberts N, Proven M, Roy NBA, Babbs C, Higgs DR, Sankaran VG, Churchman LS. RNA polymerase II pausing temporally coordinates cell cycle progression and erythroid differentiation. Dev Cell 2023; 58:2112-2127.e4. [PMID: 37586368 PMCID: PMC10615711 DOI: 10.1016/j.devcel.2023.07.018] [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: 03/14/2023] [Revised: 05/23/2023] [Accepted: 07/25/2023] [Indexed: 08/18/2023]
Abstract
Controlled release of promoter-proximal paused RNA polymerase II (RNA Pol II) is crucial for gene regulation. However, studying RNA Pol II pausing is challenging, as pause-release factors are almost all essential. In this study, we identified heterozygous loss-of-function mutations in SUPT5H, which encodes SPT5, in individuals with β-thalassemia. During erythropoiesis in healthy human cells, cell cycle genes were highly paused as cells transition from progenitors to precursors. When the pathogenic mutations were recapitulated by SUPT5H editing, RNA Pol II pause release was globally disrupted, and as cells began transitioning from progenitors to precursors, differentiation was delayed, accompanied by a transient lag in erythroid-specific gene expression and cell cycle kinetics. Despite this delay, cells terminally differentiate, and cell cycle phase distributions normalize. Therefore, hindering pause release perturbs proliferation and differentiation dynamics at a key transition during erythropoiesis, identifying a role for RNA Pol II pausing in temporally coordinating the cell cycle and erythroid differentiation.
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Affiliation(s)
- Danya J Martell
- Department of Genetics, Harvard University, Boston, MA, USA; Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Hope E Merens
- Department of Genetics, Harvard University, Boston, MA, USA
| | - Alexis Caulier
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Claudia Fiorini
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jacob C Ulirsch
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | | | - Karine Choquet
- Department of Genetics, Harvard University, Boston, MA, USA
| | - Giovanna Graziadei
- Department of Clinical Sciences and Community, University of Milan, IRCCS Ca'Granda Foundation Maggiore Policlinico Hospital, Milan, Italy
| | - Valentina Brancaleoni
- Department of Clinical Sciences and Community, University of Milan, IRCCS Ca'Granda Foundation Maggiore Policlinico Hospital, Milan, Italy
| | - Maria Domenica Cappellini
- Department of Clinical Sciences and Community, University of Milan, IRCCS Ca'Granda Foundation Maggiore Policlinico Hospital, Milan, Italy
| | - Caroline Scott
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Nigel Roberts
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Melanie Proven
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Noémi B A Roy
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK; NIHR Oxford Biomedical Research Centre and BRC/NHS Translational Molecular Diagnostics Centre, John Radcliffe Hospital, Oxford, UK; Department of Haematology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Christian Babbs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Douglas R Higgs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Vijay G Sankaran
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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11
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Hunter S, Dowell RD, Hendrix J, Freeman J, Allen MA. Transcription dosage compensation does not occur in Down syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.543933. [PMID: 37333218 PMCID: PMC10274774 DOI: 10.1101/2023.06.07.543933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Trisomy 21, also known as Down syndrome, describes the genetic condition of having an extra copy of chromosome 21. The increase in DNA copy number has led to the "DNA dosage hypothesis", which claims that the level of gene transcription is proportional to the gene's DNA copy number. Yet many reports have suggested that a proportion of chromosome 21 genes are dosage compensated back towards typical expression levels (1.0x). In contrast, other reports suggest that dosage compensation is not a common mechanism of gene regulation in Trisomy 21, providing support to the DNA dosage hypothesis. Results In our work, we use both simulated and real data to dissect the elements of differential expression analysis that can lead to the appearance of dosage compensation even when compensation is demonstrably absent. Using lymphoblastoid cell lines derived from a family of an individual with Down syndrome, we demonstrate that dosage compensation is nearly absent at both nascent transcription (GRO-seq) and steady-state RNA (RNA-seq) levels. Conclusions Transcriptional dosage compensation does not occur in Down syndrome. Simulated data containing no dosage compensation can appear to have dosage compensation when analyzed via standard methods. Moreover, some chromosome 21 genes that appear to be dosage compensated are consistent with allele specific expression.
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12
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Abril-Garrido J, Dienemann C, Grabbe F, Velychko T, Lidschreiber M, Wang H, Cramer P. Structural basis of transcription reduction by a promoter-proximal +1 nucleosome. Mol Cell 2023:S1097-2765(23)00255-1. [PMID: 37148879 DOI: 10.1016/j.molcel.2023.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/16/2023] [Accepted: 04/11/2023] [Indexed: 05/08/2023]
Abstract
At active human genes, the +1 nucleosome is located downstream of the RNA polymerase II (RNA Pol II) pre-initiation complex (PIC). However, at inactive genes, the +1 nucleosome is found further upstream, at a promoter-proximal location. Here, we establish a model system to show that a promoter-proximal +1 nucleosome can reduce RNA synthesis in vivo and in vitro, and we analyze its structural basis. We find that the PIC assembles normally when the edge of the +1 nucleosome is located 18 base pairs (bp) downstream of the transcription start site (TSS). However, when the nucleosome edge is located further upstream, only 10 bp downstream of the TSS, the PIC adopts an inhibited state. The transcription factor IIH (TFIIH) shows a closed conformation and its subunit XPB contacts DNA with only one of its two ATPase lobes, inconsistent with DNA opening. These results provide a mechanism for nucleosome-dependent regulation of transcription initiation.
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Affiliation(s)
- Julio Abril-Garrido
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Christian Dienemann
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Frauke Grabbe
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Taras Velychko
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Michael Lidschreiber
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Haibo Wang
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Patrick Cramer
- Max Planck Institute for Multidisciplinary Sciences, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
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13
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Martell DJ, Merens HE, Fiorini C, Caulier A, Ulirsch JC, Ietswaart R, Choquet K, Graziadei G, Brancaleoni V, Cappellini MD, Scott C, Roberts N, Proven M, Roy NB, Babbs C, Higgs DR, Sankaran VG, Churchman LS. RNA Polymerase II pausing temporally coordinates cell cycle progression and erythroid differentiation. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.03.23286760. [PMID: 36945604 PMCID: PMC10029049 DOI: 10.1101/2023.03.03.23286760] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The controlled release of promoter-proximal paused RNA polymerase II (Pol II) into productive elongation is a major step in gene regulation. However, functional analysis of Pol II pausing is difficult because factors that regulate pause release are almost all essential. In this study, we identified heterozygous loss-of-function mutations in SUPT5H , which encodes SPT5, in individuals with β-thalassemia unlinked to HBB mutations. During erythropoiesis in healthy human cells, cell cycle genes were highly paused at the transition from progenitors to precursors. When the pathogenic mutations were recapitulated by SUPT5H editing, Pol II pause release was globally disrupted, and the transition from progenitors to precursors was delayed, marked by a transient lag in erythroid-specific gene expression and cell cycle kinetics. Despite this delay, cells terminally differentiate, and cell cycle phase distributions normalize. Therefore, hindering pause release perturbs proliferation and differentiation dynamics at a key transition during erythropoiesis, revealing a role for Pol II pausing in the temporal coordination between the cell cycle and differentiation.
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Affiliation(s)
- Danya J Martell
- Harvard University, Department of Genetics, Boston, MA
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
- Broad Institute of MIT and Harvard, Cambridge, MA
| | - Hope E Merens
- Harvard University, Department of Genetics, Boston, MA
| | - Claudia Fiorini
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
- Broad Institute of MIT and Harvard, Cambridge, MA
| | - Alexis Caulier
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
- Broad Institute of MIT and Harvard, Cambridge, MA
| | - Jacob C Ulirsch
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
- Broad Institute of MIT and Harvard, Cambridge, MA
| | | | | | - Giovanna Graziadei
- Department of Clinical Sciences and Community, University of Milan, IRCCS Ca'Granda Foundation Maggiore Policlinico Hospital, Milan, Italy
| | - Valentina Brancaleoni
- Department of Clinical Sciences and Community, University of Milan, IRCCS Ca'Granda Foundation Maggiore Policlinico Hospital, Milan, Italy
| | - Maria Domenica Cappellini
- Department of Clinical Sciences and Community, University of Milan, IRCCS Ca'Granda Foundation Maggiore Policlinico Hospital, Milan, Italy
| | - Caroline Scott
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Nigel Roberts
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Melanie Proven
- Oxford Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Noémi Ba Roy
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre and BRC/NHS Translational Molecular Diagnostics Centre, John Radcliffe Hospital, Oxford, UK
- Department of Haematology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Christian Babbs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Douglas R Higgs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Vijay G Sankaran
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA
- Broad Institute of MIT and Harvard, Cambridge, MA
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14
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Welsh SA, Gardini A. Genomic regulation of transcription and RNA processing by the multitasking Integrator complex. Nat Rev Mol Cell Biol 2023; 24:204-220. [PMID: 36180603 PMCID: PMC9974566 DOI: 10.1038/s41580-022-00534-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2022] [Indexed: 11/09/2022]
Abstract
In higher eukaryotes, fine-tuned activation of protein-coding genes and many non-coding RNAs pivots around the regulated activity of RNA polymerase II (Pol II). The Integrator complex is the only Pol II-associated large multiprotein complex that is metazoan specific, and has therefore been understudied for years. Integrator comprises at least 14 subunits, which are grouped into distinct functional modules. The phosphodiesterase activity of the core catalytic module is co-transcriptionally directed against several RNA species, including long non-coding RNAs (lncRNAs), U small nuclear RNAs (U snRNAs), PIWI-interacting RNAs (piRNAs), enhancer RNAs and nascent pre-mRNAs. Processing of non-coding RNAs by Integrator is essential for their biogenesis, and at protein-coding genes, Integrator is a key modulator of Pol II promoter-proximal pausing and transcript elongation. Recent studies have identified an Integrator-specific serine/threonine-protein phosphatase 2A (PP2A) module, which targets Pol II and other components of the basal transcription machinery. In this Review, we discuss how the activity of Integrator regulates transcription, RNA processing, chromatin landscape and DNA repair. We also discuss the diverse roles of Integrator in development and tumorigenesis.
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15
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Wells M, Steiner L. Epigenetic and Transcriptional Control of Erythropoiesis. Front Genet 2022; 13:805265. [PMID: 35330735 PMCID: PMC8940284 DOI: 10.3389/fgene.2022.805265] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 02/16/2022] [Indexed: 12/21/2022] Open
Abstract
Erythropoiesis is a process of enormous magnitude, with the average person generating two to three million red cells every second. Erythroid progenitors start as large cells with large nuclei, and over the course of three to four cell divisions they undergo a dramatic decrease in cell size accompanied by profound nuclear condensation, which culminates in enucleation. As maturing erythroblasts are undergoing these dramatic phenotypic changes, they accumulate hemoglobin and express high levels of other erythroid-specific genes, while silencing much of the non-erythroid transcriptome. These phenotypic and gene expression changes are associated with distinct changes in the chromatin landscape, and require close coordination between transcription factors and epigenetic regulators, as well as precise regulation of RNA polymerase II activity. Disruption of these processes are associated with inherited anemias and myelodysplastic syndromes. Here, we review the epigenetic mechanisms that govern terminal erythroid maturation, and their role in human disease.
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Affiliation(s)
- Maeve Wells
- Department of Pediatrics, University of Rochester, Rochester, NY, United States
| | - Laurie Steiner
- Department of Pediatrics, University of Rochester, Rochester, NY, United States
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16
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Hunter S, Sigauke RF, Stanley JT, Allen MA, Dowell RD. Protocol variations in run-on transcription dataset preparation produce detectable signatures in sequencing libraries. BMC Genomics 2022; 23:187. [PMID: 35255806 PMCID: PMC8900324 DOI: 10.1186/s12864-022-08352-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 01/25/2022] [Indexed: 11/20/2022] Open
Abstract
Background A variety of protocols exist for producing whole genome run-on transcription datasets. However, little is known about how differences between these protocols affect the signal within the resulting libraries. Results Using run-on transcription datasets generated from the same biological system, we show that a variety of GRO- and PRO-seq preparation methods leave identifiable signatures within each library. Specifically we show that the library preparation method results in differences in quality control metrics, as well as differences in the signal distribution at the 5 ′ end of transcribed regions. These shifts lead to disparities in eRNA identification, but do not impact analyses aimed at inferring the key regulators involved in changes to transcription. Conclusions Run-on sequencing protocol variations result in technical signatures that can be used to identify both the enrichment and library preparation method of a particular data set. These technical signatures are batch effects that limit detailed comparisons of pausing ratios and eRNAs identified across protocols. However, these batch effects have only limited impact on our ability to infer which regulators underlie the observed transcriptional changes. Supplementary Information The online version contains supplementary material available at (10.1186/s12864-022-08352-8).
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Affiliation(s)
- Samuel Hunter
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
| | - Rutendo F Sigauke
- Computational Bioscience Program, Anschutz Medical Campus, University of Colorado, Aurora, 80045, USA
| | - Jacob T Stanley
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, 80301, USA
| | - Mary A Allen
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA
| | - Robin D Dowell
- BioFrontiers Institute, University of Colorado, Boulder, 80309, USA. .,Computational Bioscience Program, Anschutz Medical Campus, University of Colorado, Aurora, 80045, USA. .,Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, 80301, USA. .,Department of Computer Science, University of Colorado, Boulder, 80309, USA.
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17
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Nojima T, Proudfoot NJ. Mechanisms of lncRNA biogenesis as revealed by nascent transcriptomics. Nat Rev Mol Cell Biol 2022; 23:389-406. [DOI: 10.1038/s41580-021-00447-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2021] [Indexed: 12/14/2022]
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18
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Braichenko S, Holehouse J, Grima R. Distinguishing between models of mammalian gene expression: telegraph-like models versus mechanistic models. J R Soc Interface 2021; 18:20210510. [PMID: 34610262 PMCID: PMC8492181 DOI: 10.1098/rsif.2021.0510] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Two-state models (telegraph-like models) have a successful history of predicting distributions of cellular and nascent mRNA numbers that can well fit experimental data. These models exclude key rate limiting steps, and hence it is unclear why they are able to accurately predict the number distributions. To answer this question, here we compare these models to a novel stochastic mechanistic model of transcription in mammalian cells that presents a unified description of transcriptional factor, polymerase and mature mRNA dynamics. We show that there is a large region of parameter space where the first, second and third moments of the distributions of the waiting times between two consecutively produced transcripts (nascent or mature) of two-state and mechanistic models exactly match. In this region: (i) one can uniquely express the two-state model parameters in terms of those of the mechanistic model, (ii) the models are practically indistinguishable by comparison of their transcript numbers distributions, and (iii) they are distinguishable from the shape of their waiting time distributions. Our results clarify the relationship between different gene expression models and identify a means to select between them from experimental data.
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Affiliation(s)
- Svitlana Braichenko
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK.,School of Informatics, University of Edinburgh, Edinburgh, UK
| | - James Holehouse
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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19
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Gadad SS, Camacho CV, Malladi V, Hutti CR, Nagari A, Kraus WL. PARP-1 Regulates Estrogen-Dependent Gene Expression in Estrogen Receptor α-Positive Breast Cancer Cells. Mol Cancer Res 2021; 19:1688-1698. [PMID: 34158394 PMCID: PMC8492518 DOI: 10.1158/1541-7786.mcr-21-0103] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/01/2021] [Accepted: 06/09/2021] [Indexed: 11/16/2022]
Abstract
Poly(ADP-ribose) polymerase-1 (PARP-1) has gained considerable attention as a target for therapeutic inhibitors in breast cancers. Previously we showed that PARP-1 localizes to active gene promoters to regulate histone methylation and RNA polymerase II activity (Pol II), altering the expression of various tumor-related genes. Here we report a role for PARP-1 in estrogen-dependent transcription in estrogen receptor alpha (ERα)-positive (ER+) breast cancers. Global nuclear run-on and sequencing analyses functionally linked PARP-1 to the direct control of estrogen-regulated gene expression in ER+ MCF-7 breast cancer cells by promoting transcriptional elongation by Pol II. Furthermore, chromatin immunoprecipitation sequencing analyses revealed that PARP-1 regulates the estrogen-dependent binding of ERα and FoxA1 to a subset of genomic ERα binding sites, promoting active enhancer formation. Moreover, we found that the expression levels of the PARP-1- and estrogen-coregulated gene set are enriched in the luminal subtype of breast cancer, and high PARP-1 expression in ER+ cases correlates with poor survival. Finally, treatment with a PARP inhibitor or a transcriptional elongation inhibitor attenuated estrogen-dependent growth of multiple ER+ breast cancer cell lines. Taken together, our results show that PARP-1 regulates critical molecular pathways that control the estrogen-dependent gene expression program underlying the proliferation of ER+ breast cancer cells. IMPLICATIONS: PARP-1 regulates the estrogen-dependent genomic binding of ERα and FoxA1 to regulate critical gene expression programs by RNA Pol II that underlie the proliferation of ER+ breast cancers, providing a potential therapeutic opportunity for PARP inhibitors in estrogen-responsive breast cancers.
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Affiliation(s)
- Shrikanth S Gadad
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, Texas.
- Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas
- Center of Emphasis in Cancer, Department of Molecular and Translational Medicine, Texas Tech University Health Sciences Center El Paso, Texas
| | - Cristel V Camacho
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Venkat Malladi
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Charles R Hutti
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Anusha Nagari
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, Texas
| | - W Lee Kraus
- Laboratory of Signaling and Gene Regulation, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, Texas.
- Division of Basic Research, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas
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20
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Rubin JD, Stanley JT, Sigauke RF, Levandowski CB, Maas ZL, Westfall J, Taatjes DJ, Dowell RD. Transcription factor enrichment analysis (TFEA) quantifies the activity of multiple transcription factors from a single experiment. Commun Biol 2021; 4:661. [PMID: 34079046 PMCID: PMC8172830 DOI: 10.1038/s42003-021-02153-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/20/2021] [Indexed: 02/04/2023] Open
Abstract
Detecting changes in the activity of a transcription factor (TF) in response to a perturbation provides insights into the underlying cellular process. Transcription Factor Enrichment Analysis (TFEA) is a robust and reliable computational method that detects positional motif enrichment associated with changes in transcription observed in response to a perturbation. TFEA detects positional motif enrichment within a list of ranked regions of interest (ROIs), typically sites of RNA polymerase initiation inferred from regulatory data such as nascent transcription. Therefore, we also introduce muMerge, a statistically principled method of generating a consensus list of ROIs from multiple replicates and conditions. TFEA is broadly applicable to data that informs on transcriptional regulation including nascent transcription (eg. PRO-Seq), CAGE, histone ChIP-Seq, and accessibility data (e.g., ATAC-Seq). TFEA not only identifies the key regulators responding to a perturbation, but also temporally unravels regulatory networks with time series data. Consequently, TFEA serves as a hypothesis-generating tool that provides an easy, rigorous, and cost-effective means to broadly assess TF activity yielding new biological insights.
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Affiliation(s)
- Jonathan D Rubin
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
| | - Jacob T Stanley
- BioFrontiers Institute, University of Colorado, Boulder, CO, USA
| | - Rutendo F Sigauke
- Computational Bioscience Program, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA
| | | | - Zachary L Maas
- BioFrontiers Institute, University of Colorado, Boulder, CO, USA
| | - Jessica Westfall
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Dylan J Taatjes
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
| | - Robin D Dowell
- BioFrontiers Institute, University of Colorado, Boulder, CO, USA.
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA.
- Department of Computer Science, University of Colorado, Boulder, CO, USA.
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21
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Clapier CR. Sophisticated Conversations between Chromatin and Chromatin Remodelers, and Dissonances in Cancer. Int J Mol Sci 2021; 22:5578. [PMID: 34070411 PMCID: PMC8197500 DOI: 10.3390/ijms22115578] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 01/13/2023] Open
Abstract
The establishment and maintenance of genome packaging into chromatin contribute to define specific cellular identity and function. Dynamic regulation of chromatin organization and nucleosome positioning are critical to all DNA transactions-in particular, the regulation of gene expression-and involve the cooperative action of sequence-specific DNA-binding factors, histone modifying enzymes, and remodelers. Remodelers are molecular machines that generate various chromatin landscapes, adjust nucleosome positioning, and alter DNA accessibility by using ATP binding and hydrolysis to perform DNA translocation, which is highly regulated through sophisticated structural and functional conversations with nucleosomes. In this review, I first present the functional and structural diversity of remodelers, while emphasizing the basic mechanism of DNA translocation, the common regulatory aspects, and the hand-in-hand progressive increase in complexity of the regulatory conversations between remodelers and nucleosomes that accompanies the increase in challenges of remodeling processes. Next, I examine how, through nucleosome positioning, remodelers guide the regulation of gene expression. Finally, I explore various aspects of how alterations/mutations in remodelers introduce dissonance into the conversations between remodelers and nucleosomes, modify chromatin organization, and contribute to oncogenesis.
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Affiliation(s)
- Cedric R Clapier
- Department of Oncological Sciences & Howard Hughes Medical Institute, Huntsman Cancer Institute, University of Utah School of Medicine, 2000 Circle of Hope, Salt Lake City, UT 84112, USA
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22
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Schnell AP, Kohrt S, Thoma-Kress AK. Latency Reversing Agents: Kick and Kill of HTLV-1? Int J Mol Sci 2021; 22:ijms22115545. [PMID: 34073995 PMCID: PMC8197370 DOI: 10.3390/ijms22115545] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 12/14/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1), the cause of adult T-cell leukemia/lymphoma (ATLL), is a retrovirus, which integrates into the host genome and persistently infects CD4+ T-cells. Virus propagation is stimulated by (1) clonal expansion of infected cells and (2) de novo infection. Viral gene expression is induced by the transactivator protein Tax, which recruits host factors like positive transcription elongation factor b (P-TEFb) to the viral promoter. Since HTLV-1 gene expression is repressed in vivo by viral, cellular, and epigenetic mechanisms in late phases of infection, HTLV-1 avoids an efficient CD8+ cytotoxic T-cell (CTL) response directed against the immunodominant viral Tax antigen. Hence, therapeutic strategies using latency reversing agents (LRAs) sought to transiently activate viral gene expression and antigen presentation of Tax to enhance CTL responses towards HTLV-1, and thus, to expose the latent HTLV-1 reservoir to immune destruction. Here, we review strategies that aimed at enhancing Tax expression and Tax-specific CTL responses to interfere with HTLV-1 latency. Further, we provide an overview of LRAs including (1) histone deacetylase inhibitors (HDACi) and (2) activators of P-TEFb, that have mainly been studied in context of human immunodeficiency virus (HIV), but which may also be powerful in the context of HTLV-1.
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23
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Wang Y, Mao Y, Zhao Y, Yi X, Ding G, Yu C, Sheng J, Liu X, Meng Y, Huang H. Early-life undernutrition induces enhancer RNA remodeling in mice liver. Epigenetics Chromatin 2021; 14:18. [PMID: 33789751 PMCID: PMC8011416 DOI: 10.1186/s13072-021-00392-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 03/19/2021] [Indexed: 01/10/2023] Open
Abstract
Background Maternal protein restriction diet (PRD) increases the risk of metabolic dysfunction in adulthood, the mechanisms during the early life of offspring are still poorly understood. Apart from genetic factors, epigenetic mechanisms are crucial to offer phenotypic plasticity in response to environmental situations and transmission. Enhancer-associated noncoding RNAs (eRNAs) transcription serves as a robust indicator of enhancer activation, and have potential roles in mediating enhancer functions and gene transcription. Results Using global run-on sequencing (GRO-seq) of nascent RNA including eRNA and total RNA sequencing data, we show that early-life undernutrition causes remodeling of enhancer activity in mouse liver. Differentially expressed nascent active genes were enriched in metabolic pathways. Besides, our work detected a large number of high confidence enhancers based on eRNA transcription at the ages of 4 weeks and 7 weeks, respectively. Importantly, except for ~ 1000 remodeling enhancers, the early-life undernutrition induced instability of enhancer activity which decreased in 4 weeks and increased in adulthood. eRNA transcription mainly contributes to the regulation of some important metabolic enzymes, suggesting a link between metabolic dysfunction and enhancer transcriptional control. We discovered a novel eRNA that is positively correlated to the expression of circadian gene Cry1 with increased binding of epigenetic cofactor p300. Conclusions Our study reveals novel insights into mechanisms of metabolic dysfunction. Enhancer activity in early life acts on metabolism-associated genes, leading to the increased susceptibility of metabolic disorders. Supplementary Information The online version contains supplementary material available at 10.1186/s13072-021-00392-w.
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Affiliation(s)
- Yinyu Wang
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yiting Mao
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yiran Zhao
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xianfu Yi
- School of Biomedical Engineering and Technology, Tianjin Medical University, Tianjin, China
| | - Guolian Ding
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China.,Institute of Embryo-Fetal Original Adult Disease Affiliated To Shanghai, Jiao Tong University School of Medicine, Shanghai, China
| | - Chuanjin Yu
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China.,Institute of Embryo-Fetal Original Adult Disease Affiliated To Shanghai, Jiao Tong University School of Medicine, Shanghai, China
| | - Jianzhong Sheng
- Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China.,Department of Pathology and Pathophysiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xinmei Liu
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China.,Institute of Embryo-Fetal Original Adult Disease Affiliated To Shanghai, Jiao Tong University School of Medicine, Shanghai, China
| | - Yicong Meng
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. .,Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China. .,Institute of Embryo-Fetal Original Adult Disease Affiliated To Shanghai, Jiao Tong University School of Medicine, Shanghai, China.
| | - Hefeng Huang
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. .,Shanghai Key Laboratory of Embryo Original Disease, Shanghai, China. .,Institute of Embryo-Fetal Original Adult Disease Affiliated To Shanghai, Jiao Tong University School of Medicine, Shanghai, China.
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24
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Sousa-Luís R, Dujardin G, Zukher I, Kimura H, Weldon C, Carmo-Fonseca M, Proudfoot NJ, Nojima T. POINT technology illuminates the processing of polymerase-associated intact nascent transcripts. Mol Cell 2021; 81:1935-1950.e6. [PMID: 33735606 PMCID: PMC8122139 DOI: 10.1016/j.molcel.2021.02.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/21/2020] [Accepted: 02/24/2021] [Indexed: 12/29/2022]
Abstract
Mammalian chromatin is the site of both RNA polymerase II (Pol II) transcription and coupled RNA processing. However, molecular details of such co-transcriptional mechanisms remain obscure, partly because of technical limitations in purifying authentic nascent transcripts. We present a new approach to characterize nascent RNA, called polymerase intact nascent transcript (POINT) technology. This three-pronged methodology maps nascent RNA 5′ ends (POINT-5), establishes the kinetics of co-transcriptional splicing patterns (POINT-nano), and profiles whole transcription units (POINT-seq). In particular, we show by depletion of the nuclear exonuclease Xrn2 that this activity acts selectively on cleaved 5′ P-RNA at polyadenylation sites. Furthermore, POINT-nano reveals that co-transcriptional splicing either occurs immediately after splice site transcription or is delayed until Pol II transcribes downstream sequences. Finally, we connect RNA cleavage and splicing with either premature or full-length transcript termination. We anticipate that POINT technology will afford full dissection of the complexity of co-transcriptional RNA processing. POINT methodology dissects intact nascent RNA processing Specificity of Xrn2 exonuclease in co-transcriptional RNA degradation Splicing suppresses Xrn2-dependent premature termination Different kinetic classes of co-transcriptional splicing in human genes
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Affiliation(s)
- Rui Sousa-Luís
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisbon, Portugal
| | - Gwendal Dujardin
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Inna Zukher
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Hiroshi Kimura
- Cell Biology Centre, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Carika Weldon
- Wellcome Trust Center for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Maria Carmo-Fonseca
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Professor Egas Moniz, 1649-028 Lisbon, Portugal.
| | - Nick J Proudfoot
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
| | - Takayuki Nojima
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK; Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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25
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Abstract
Post-transcriptional processing strongly affects the stability and the relative quantification of RNA molecules, so that steady-state levels of mature RNA, such as mRNAs, rarely reflect accurately the rate of in situ transcription in nuclei by RNA polymerases (RNAPs). The "Global Run-on Sequencing (GRO-Seq)" method, developed in 2008, combines the nuclear run-on assay with next-generation deep sequencing to detect nascent RNA levels to annotate the positions, the relative levels and the orientation of transcriptionally engaged RNA polymerase II (RNAPII) molecules genome-wide. Thus, GRO-Seq is a powerful method to infer mechanistic insights into the multiple levels of transcriptional regulation such as promoter-proximal pausing of RNAP, bidirectional transcription, and enhancer activity. Here, we describe a protocol for mammalian cells that can reliably detect low abundant nascent RNA from both coding and noncoding genomic regions. This protocol can easily be adapted for most mammalian cells to define the transcriptionally active regions of the genome and to measure dynamic transcriptional responses with high sensitivity upon external stimuli.
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The ARF tumor suppressor targets PPM1G/PP2Cγ to counteract NF-κB transcription tuning cell survival and the inflammatory response. Proc Natl Acad Sci U S A 2020; 117:32594-32605. [PMID: 33288725 DOI: 10.1073/pnas.2004470117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Inducible transcriptional programs mediate the regulation of key biological processes and organismal functions. Despite their complexity, cells have evolved mechanisms to precisely control gene programs in response to environmental cues to regulate cell fate and maintain normal homeostasis. Upon stimulation with proinflammatory cytokines such as tumor necrosis factor-α (TNF), the master transcriptional regulator nuclear factor (NF)-κB utilizes the PPM1G/PP2Cγ phosphatase as a coactivator to normally induce inflammatory and cell survival programs. However, how PPM1G activity is precisely regulated to control NF-κB transcription magnitude and kinetics remains unknown. Here, we describe a mechanism by which the ARF tumor suppressor binds PPM1G to negatively regulate its coactivator function in the NF-κB circuit thereby promoting insult resolution. ARF becomes stabilized upon binding to PPM1G and forms a ternary protein complex with PPM1G and NF-κB at target gene promoters in a stimuli-dependent manner to provide tunable control of the NF-κB transcriptional program. Consistently, loss of ARF in colon epithelial cells leads to up-regulation of NF-κB antiapoptotic genes upon TNF stimulation and renders cells partially resistant to TNF-induced apoptosis in the presence of agents blocking the antiapoptotic program. Notably, patient tumor data analysis validates these findings by revealing that loss of ARF strongly correlates with sustained expression of inflammatory and cell survival programs. Collectively, we propose that PPM1G emerges as a therapeutic target in a variety of cancers arising from ARF epigenetic silencing, to loss of ARF function, as well as tumors bearing oncogenic NF-κB activation.
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Severinova E, Alikunju S, Deng W, Dhawan P, Sayed N, Sayed D. Glucocorticoid Receptor-Binding and Transcriptome Signature in Cardiomyocytes. J Am Heart Assoc 2020; 8:e011484. [PMID: 30866692 PMCID: PMC6475044 DOI: 10.1161/jaha.118.011484] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Background An increase in serum cortisol has been identified as a risk factor for cardiac failure, which highlights the impact of glucocorticoid signaling in cardiomyocytes and its influence in the progression of failure. Dexamethasone, a synthetic glucocorticoid, is sufficient for induction of cardiomyocyte hypertrophy, but little is known of the glucocorticoid receptor (GR) genome‐binding and ‐dependent transcriptional changes that mediate this phenotype. Methods and Results In this study using high‐resolution sequencing, we identified genomic targets of GR and associated change in the transcriptome after 1 and 24 hours of dexamethasone treatment. We showed that GR associates with 6482 genes in the cardiac genome, with differential regulation of 738 genes. Interestingly, alignment of the chromatin immunoprecipitation and RNA sequencing data show that, after 1 hour, 69% of differentially regulated genes are associated with GR and identify as regulators of RNA pol II–dependent transcription. Conversely, after 24 hours only 45% of regulated genes are associated with GR and involved in dilated and hypertrophic cardiomyopathies as well as other growth‐related pathways. In addition, our data also reveal that a majority of genes (76.42%) associated with GR show incremental changes in transcript abundance and are genes involved in basic cellular processes that might be regulated by the dynamics of promoter‐paused RNA pol II, as seen in hearts undergoing hypertrophy. In vivo administration of dexamethasone resulted in similar changes in the cardiac transcriptome, as seen in isolated cardiomyocytes. Conclusions Our data reveal genome‐wide GR binding sites in cardiomyocytes, identify novel targets and GR‐dependent change in the transcriptome that induces and contributes to cardiomyocyte hypertrophy.
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Affiliation(s)
- Elena Severinova
- 1 Department of Cell Biology and Molecular Medicine Rutgers New Jersey Medical School Newark NJ
| | - Saleena Alikunju
- 1 Department of Cell Biology and Molecular Medicine Rutgers New Jersey Medical School Newark NJ
| | - Wei Deng
- 1 Department of Cell Biology and Molecular Medicine Rutgers New Jersey Medical School Newark NJ
| | - Puneet Dhawan
- 2 Genomics Center Department of Microbiology Biochemistry and Molecular Genetics Rutgers New Jersey Medical School Newark NJ
| | - Nazish Sayed
- 3 Cardiovascular Institute Stanford University Stanford CA
| | - Danish Sayed
- 1 Department of Cell Biology and Molecular Medicine Rutgers New Jersey Medical School Newark NJ
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28
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Qiu C, Jin H, Vvedenskaya I, Llenas JA, Zhao T, Malik I, Visbisky AM, Schwartz SL, Cui P, Čabart P, Han KH, Lai WKM, Metz RP, Johnson CD, Sze SH, Pugh BF, Nickels BE, Kaplan CD. Universal promoter scanning by Pol II during transcription initiation in Saccharomyces cerevisiae. Genome Biol 2020; 21:132. [PMID: 32487207 PMCID: PMC7265651 DOI: 10.1186/s13059-020-02040-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 05/08/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The majority of eukaryotic promoters utilize multiple transcription start sites (TSSs). How multiple TSSs are specified at individual promoters across eukaryotes is not understood for most species. In Saccharomyces cerevisiae, a pre-initiation complex (PIC) comprised of Pol II and conserved general transcription factors (GTFs) assembles and opens DNA upstream of TSSs. Evidence from model promoters indicates that the PIC scans from upstream to downstream to identify TSSs. Prior results suggest that TSS distributions at promoters where scanning occurs shift in a polar fashion upon alteration in Pol II catalytic activity or GTF function. RESULTS To determine the extent of promoter scanning across promoter classes in S. cerevisiae, we perturb Pol II catalytic activity and GTF function and analyze their effects on TSS usage genome-wide. We find that alterations to Pol II, TFIIB, or TFIIF function widely alter the initiation landscape consistent with promoter scanning operating at all yeast promoters, regardless of promoter class. Promoter architecture, however, can determine the extent of promoter sensitivity to altered Pol II activity in ways that are predicted by a scanning model. CONCLUSIONS Our observations coupled with previous data validate key predictions of the scanning model for Pol II initiation in yeast, which we term the shooting gallery. In this model, Pol II catalytic activity and the rate and processivity of Pol II scanning together with promoter sequence determine the distribution of TSSs and their usage.
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Affiliation(s)
- Chenxi Qiu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
- Present Address: Department of Medicine, Division of Translational Therapeutics, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA
| | - Huiyan Jin
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Irina Vvedenskaya
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Genetics, Rutgers University, Piscataway, NJ, 08854, USA
| | - Jordi Abante Llenas
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, 77843-3128, USA
- Present Address: Whitaker Biomedical Engineering Institute, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Tingting Zhao
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Indranil Malik
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
- Present Address: Department of Neurology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Alex M Visbisky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Scott L Schwartz
- Genomics and Bioinformatics Service, Texas A&M AgriLife, College Station, TX, 77845, USA
| | - Ping Cui
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Pavel Čabart
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
- Present Address: First Faculty of Medicine, Charles University, BIOCEV, 252 42, Vestec, Czech Republic
| | - Kang Hoo Han
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, 16802, USA
| | - William K M Lai
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, 16802, USA
- Present Address: Department of Molecular Biology and Genetics, 458 Biotechnology, Cornell University, New York, 14853, USA
| | - Richard P Metz
- Genomics and Bioinformatics Service, Texas A&M AgriLife, College Station, TX, 77845, USA
| | - Charles D Johnson
- Genomics and Bioinformatics Service, Texas A&M AgriLife, College Station, TX, 77845, USA
| | - Sing-Hoi Sze
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
- Department of Computer Science and Engineering, Texas A&M University, College Station, TX, 77843-3127, USA
| | - B Franklin Pugh
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, 16802, USA
- Present Address: Department of Molecular Biology and Genetics, 458 Biotechnology, Cornell University, New York, 14853, USA
| | - Bryce E Nickels
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Genetics, Rutgers University, Piscataway, NJ, 08854, USA
| | - Craig D Kaplan
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
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Fitz J, Neumann T, Steininger M, Wiedemann EM, Garcia AC, Athanasiadis A, Schoeberl UE, Pavri R. Spt5-mediated enhancer transcription directly couples enhancer activation with physical promoter interaction. Nat Genet 2020; 52:505-515. [PMID: 32251373 DOI: 10.1038/s41588-020-0605-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 02/28/2020] [Indexed: 12/19/2022]
Abstract
Active enhancers are frequently transcribed, yet the regulatory role of enhancer transcription remains debated. Here, we depleted the RNA polymerase II pausing and elongation factor Spt5 in activated mouse B cells and found that approximately 50% of enhancer-gene pairs showed co-regulated transcription, consistent with a potential functional requirement for enhancer transcription. In particular, Spt5 depletion led to loss of super-enhancer-promoter physical interaction and gene expression at the immunoglobulin heavy-chain locus (Igh), abrogating antibody class switch recombination. This defect correlated strictly with loss of enhancer transcription but did not affect acetylation of histone H3 at lysine 27, chromatin accessibility and occupancy of Mediator and cohesin at the enhancer. Strikingly, CRISPRa-mediated rescue of enhancer transcription in Spt5-depleted cells restored Igh gene expression. Our work suggests that Spt5-mediated enhancer transcription underlies the physical and functional interaction between a subset of active enhancers and their target promoters.
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Affiliation(s)
- Johanna Fitz
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Tobias Neumann
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | | | | | | | | | | | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna, Austria.
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30
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Sithole N, Williams CA, Abbink TEM, Lever AML. DDX5 potentiates HIV-1 transcription as a co-factor of Tat. Retrovirology 2020; 17:6. [PMID: 32228614 PMCID: PMC7106839 DOI: 10.1186/s12977-020-00514-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/16/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND HIV-1 does not encode a helicase and hijacks those of the cell for efficient replication. We and others previously showed that the DEAD box helicase, DDX5, is an essential HIV dependency factor. DDX5 was recently shown to be associated with the 7SK snRNP. Cellular positive transcription elongation factor b (P-TEFb) is bound in an inactive form with HEXIM1/2 on 7SK snRNP. The Tat/P-TEFb complex is essential for efficient processivity of Pol II in HIV-1 transcription elongation and Tat competes with HEXIM1/2 for P-TEFb. We investigated the precise role of DDX5 in HIV replication using siRNA mediated knockdown and rescue with DDX5 mutants which prevent protein-protein interactions and RNA and ATP binding. RESULTS We demonstrate a critical role for DDX5 in the Tat/HEXIM1 interaction. DDX5 acts to potentiate Tat activity and can bind both Tat and HEXIM1 suggesting it may facilitate the dissociation of HEXIM1/2 from the 7SK-snRNP complex, enhancing Tat/P-TEFb availability. We show knockdown of DDX5 in a T cell line significantly reduces HIV-1 infectivity and viral protein production. This activity is unique to DDX5 and cannot be substituted by its close paralog DDX17. Overexpression of DDX5 stimulates the Tat/LTR promoter but suppresses other cellular and viral promoters. Individual mutations of conserved ATP binding, RNA binding, helicase related or protein binding motifs within DDX5 show that the N terminal RNA binding motifs, the Walker B and the glycine doublet motifs are essential for this function. The Walker A and RNA binding motifs situated on the transactivation domain are however dispensable. CONCLUSION DDX5 is an essential cellular factor for efficient HIV transcription elongation. It interacts with Tat and may potentiate the availability of P-TEFb through sequestering HEXIM1.
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Affiliation(s)
- Nyaradzai Sithole
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
| | - Claire A Williams
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
- Department of Microbiology, Specialist Virology Centre, Norfolk and Norwich University Hospitals, Norwich, UK
| | - Truus E M Abbink
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK
- Department of Paediatrics, Child Neurology, Centre for Childhood White Matter Disorders, VU University Medical Centre, Amsterdam, The Netherlands
| | - Andrew M L Lever
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK.
- Department of Medicine, National University of Singapore, Singapore, 119228, Singapore.
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31
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Ait-Ammar A, Kula A, Darcis G, Verdikt R, De Wit S, Gautier V, Mallon PWG, Marcello A, Rohr O, Van Lint C. Current Status of Latency Reversing Agents Facing the Heterogeneity of HIV-1 Cellular and Tissue Reservoirs. Front Microbiol 2020; 10:3060. [PMID: 32038533 PMCID: PMC6993040 DOI: 10.3389/fmicb.2019.03060] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/18/2019] [Indexed: 12/15/2022] Open
Abstract
One of the most explored therapeutic approaches aimed at eradicating HIV-1 reservoirs is the "shock and kill" strategy which is based on HIV-1 reactivation in latently-infected cells ("shock" phase) while maintaining antiretroviral therapy (ART) in order to prevent spreading of the infection by the neosynthesized virus. This kind of strategy allows for the "kill" phase, during which latently-infected cells die from viral cytopathic effects or from host cytolytic effector mechanisms following viral reactivation. Several latency reversing agents (LRAs) with distinct mechanistic classes have been characterized to reactivate HIV-1 viral gene expression. Some LRAs have been tested in terms of their potential to purge latent HIV-1 in vivo in clinical trials, showing that reversing HIV-1 latency is possible. However, LRAs alone have failed to reduce the size of the viral reservoirs. Together with the inability of the immune system to clear the LRA-activated reservoirs and the lack of specificity of these LRAs, the heterogeneity of the reservoirs largely contributes to the limited success of clinical trials using LRAs. Indeed, HIV-1 latency is established in numerous cell types that are characterized by distinct phenotypes and metabolic properties, and these are influenced by patient history. Hence, the silencing mechanisms of HIV-1 gene expression in these cellular and tissue reservoirs need to be better understood to rationally improve this cure strategy and hopefully reach clinical success.
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Affiliation(s)
- Amina Ait-Ammar
- Service of Molecular Virology, Department of Molecular Virology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Anna Kula
- Malopolska Centre of Biotechnology, Laboratory of Virology, Jagiellonian University, Krakow, Poland
| | - Gilles Darcis
- Infectious Diseases Department, Liège University Hospital, Liège, Belgium
| | - Roxane Verdikt
- Service of Molecular Virology, Department of Molecular Virology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
| | - Stephane De Wit
- Service des Maladies Infectieuses, CHU Saint-Pierre, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Virginie Gautier
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Patrick W G Mallon
- UCD Centre for Experimental Pathogen Host Research (CEPHR), School of Medicine, University College Dublin, Dublin, Ireland
| | - Alessandro Marcello
- Laboratory of Molecular Virology, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Olivier Rohr
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Carine Van Lint
- Service of Molecular Virology, Department of Molecular Virology (DBM), Université Libre de Bruxelles (ULB), Gosselies, Belgium
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33
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Yukl SA, Kaiser P, Kim P, Telwatte S, Joshi SK, Vu M, Lampiris H, Wong JK. HIV latency in isolated patient CD4 + T cells may be due to blocks in HIV transcriptional elongation, completion, and splicing. Sci Transl Med 2019; 10:10/430/eaap9927. [PMID: 29491188 DOI: 10.1126/scitranslmed.aap9927] [Citation(s) in RCA: 214] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 11/10/2017] [Indexed: 12/16/2022]
Abstract
Latently infected CD4+ T cells are the main barrier to complete clearance of HIV infection, but it is unclear what mechanisms govern latent HIV infection in vivo. To address this question, we developed a new panel of reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) assays specific for different HIV transcripts that define distinct blocks to transcription. We applied this panel of assays to CD4+ T cells freshly isolated from HIV-infected patients on suppressive antiretroviral therapy (ART) to quantify the degree to which different mechanisms inhibit HIV transcription. In addition, we measured the degree to which these transcriptional blocks could be reversed ex vivo by T cell activation (using anti-CD3/CD28 antibodies) or latency-reversing agents. We found that the main reversible block to HIV RNA transcription was not inhibition of transcriptional initiation but rather a series of blocks to proximal elongation, distal transcription/polyadenylation (completion), and multiple splicing. Cell dilution experiments suggested that these mechanisms operated in most of the HIV-infected CD4+ T cells examined. Latency-reversing agents exerted differential effects on the three blocks to HIV transcription, suggesting that these blocks may be governed by different mechanisms.
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Affiliation(s)
- Steven A Yukl
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA.
| | - Philipp Kaiser
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA
| | - Peggy Kim
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA
| | - Sushama Telwatte
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA
| | - Sunil K Joshi
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA
| | - Mai Vu
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA
| | - Harry Lampiris
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA
| | - Joseph K Wong
- San Francisco Veterans Affairs Medical Center and University of California, San Francisco, 4150 Clement Street, 111W, San Francisco, CA 94121, USA
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Abstract
Numerous studies based on new single-cell and single-gene techniques show that individual genes can be transcribed in short bursts or pulses accompanied by changes in pulsing frequencies. Since so many examples of such discontinuous or fluctuating transcription have been found from prokaryotes to mammals, it now seems to be a common mode of gene expression. In this review we discuss the occurrence of the transcriptional fluctuations, the techniques used for their detection, their putative causes, kinetic characteristics, and probable physiological significance.
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Affiliation(s)
- Evgeny Smirnov
- a Institute of Biology and Medical Genetics , First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
| | - Matúš Hornáček
- a Institute of Biology and Medical Genetics , First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
| | - Tomáš Vacík
- a Institute of Biology and Medical Genetics , First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
| | - Dušan Cmarko
- a Institute of Biology and Medical Genetics , First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
| | - Ivan Raška
- a Institute of Biology and Medical Genetics , First Faculty of Medicine , Charles University and General University Hospital in Prague , Prague , Czech Republic
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Zheng B, Mai Q, Jiang J, Zhou Q. The Therapeutic Potential of Small Activating RNAs for Colorectal Carcinoma. Curr Gene Ther 2019; 19:140-146. [PMID: 31284860 DOI: 10.2174/1566523219666190708111404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 05/17/2019] [Accepted: 06/02/2019] [Indexed: 12/15/2022]
Abstract
Small double-strand RNAs have been recognized as master regulators of gene expression.
In contrast to the evolutionary conserved RNA interference machinery, which degrades or inhibits the
translation of target mRNAs, small activating RNA (saRNA) activates the specific gene in a target dependent
manner through a similar mechanism as RNAi. Recently, saRNA mediated expression regulation
of specific genes has been extensively studied in cancer researches. Of particular interest is the
application of the RNA mediated gene activation within colorectal cancer (CRC) development, due to
the high incidence of the CRC. In this review, we summarize the current knowledge of saRNA mediated
genetic activation and its underlying mechanisms. Furthermore, we highlight the advantages of
the utilization of saRNAs induced gene expression as an investigating tool in colorectal cancer research.
Finally, the possibility and the challenge of the saRNA application as a potential therapy for
colorectal cancer are addressed.
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Affiliation(s)
- Bin Zheng
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - QingYun Mai
- The Center for Reproductive medicine, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - JinXing Jiang
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - QinQin Zhou
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
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Stark R, Grzelak M, Hadfield J. RNA sequencing: the teenage years. Nat Rev Genet 2019; 20:631-656. [DOI: 10.1038/s41576-019-0150-2] [Citation(s) in RCA: 679] [Impact Index Per Article: 135.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2019] [Indexed: 12/12/2022]
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Wang Y, Sun L, Luo Y, He S. Knockdown of KDM1B inhibits cell proliferation and induces apoptosis of pancreatic cancer cells. Pathol Res Pract 2019; 215:1054-1060. [PMID: 30846414 DOI: 10.1016/j.prp.2019.02.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/23/2019] [Accepted: 02/26/2019] [Indexed: 02/07/2023]
Abstract
Pancreatic cancer (PC) is one of the common malignant tumors in digestive tract with a high fatality rate. The oncogenic role of lysine-specific demethylase1 (LSD1/KDM1 A) has been well recognized in PC. While, the role of its homolog LSD2 (KDM1B) in regulating PC progression is poorly understood. In this study, we attempted to evaluate the functional role of KDM1B in PC cells. The expression of KDM1B was detected by immunohistochemistry and immunoblotting in PC tissues and cells. Lentivirus-mediated shRNA was applied to silence KDM1B in PANC-1 and SW1990 cells. Cell proliferation was measured by MTT and Celigo assay. Cell apoptosis was determined by both Caspase-Glo®3/7 assay and Flow cytometry. Intracellular signaling molecules were detected using a PathScan intracellular signaling array kit. In this study, we found KDM1B was highly expressed in PC tissues compared to paracancerous tissues. Moreover, elevated expression of KDM1B was detected in PC cell lines (BxPC-3, CFPAC-1, PANC-1 and SW1990) as compared with a normal human pancreatic duct epithelial cell line (HPDE6-C7). Further investigations revealed that KDM1B knockdown significantly inhibited PC cell proliferation. Furthermore, the apoptosis of PANC-1 and SW1990 cells was significantly increased after KDM1B knockdown. Notably, the activations of p-ERK1/2, p-Smad2, p-p53, cleaved PARP, cleaved Caspase-3, cleaved Caspase-7, p-eIF2a and Survivin were promoted by KDM1B knockdown, while IkBa was suppressed. Taken together, our findings provided new insights into the critical and multifaceted roles of KDM1B in the regulation of cell proliferation and apoptosis, and offered a potentially novel target in preventing the progression of PC.
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Affiliation(s)
- Yun Wang
- Department of Gastroenterology, The First Hospital of Xian Jiaotong University, Xi'an, 710061, China
| | - Liankang Sun
- Department of Hepatobiliary Surgery, The First Hospital of Xian Jiaotong University, Xi'an, 710061, China
| | - Yumei Luo
- Department of Gastroenterology, The First Hospital of Xian Jiaotong University, Xi'an, 710061, China
| | - Shuixiang He
- Department of Gastroenterology, The First Hospital of Xian Jiaotong University, Xi'an, 710061, China.
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Bartman CR, Hamagami N, Keller CA, Giardine B, Hardison RC, Blobel GA, Raj A. Transcriptional Burst Initiation and Polymerase Pause Release Are Key Control Points of Transcriptional Regulation. Mol Cell 2019; 73:519-532.e4. [PMID: 30554946 PMCID: PMC6368450 DOI: 10.1016/j.molcel.2018.11.004] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/06/2018] [Accepted: 11/01/2018] [Indexed: 11/16/2022]
Abstract
Transcriptional regulation occurs via changes to rates of different biochemical steps of transcription, but it remains unclear which rates are subject to change upon biological perturbation. Biochemical studies have suggested that stimuli predominantly affect the rates of RNA polymerase II (Pol II) recruitment and polymerase release from promoter-proximal pausing. Single-cell studies revealed that transcription occurs in discontinuous bursts, suggesting that features of such bursts like frequency and intensity could also be regulated. We combined Pol II chromatin immunoprecipitation sequencing (ChIP-seq) and single-cell transcriptional measurements to show that an independently regulated burst initiation step is required before polymerase recruitment can occur. Using a number of global and targeted transcriptional regulatory perturbations, we showed that biological perturbations regulated both burst initiation and polymerase pause release rates but seemed not to regulate polymerase recruitment rate. Our results suggest that transcriptional regulation primarily acts by changing the rates of burst initiation and polymerase pause release.
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Affiliation(s)
- Caroline R Bartman
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicole Hamagami
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cheryl A Keller
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Belinda Giardine
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Ross C Hardison
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Gerd A Blobel
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Arjun Raj
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Aprile-Garcia F, Tomar P, Hummel B, Khavaran A, Sawarkar R. Nascent-protein ubiquitination is required for heat shock–induced gene downregulation in human cells. Nat Struct Mol Biol 2019; 26:137-146. [DOI: 10.1038/s41594-018-0182-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 12/21/2018] [Indexed: 12/20/2022]
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NETSeq reveals heterogeneous nucleotide incorporation by RNA polymerase I. Proc Natl Acad Sci U S A 2018; 115:E11633-E11641. [PMID: 30482860 PMCID: PMC6294894 DOI: 10.1073/pnas.1809421115] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DNA sequence motifs that affect RNA polymerase transcription elongation are well studied in prokaryotic organisms and contribute directly to regulation of gene expression. Despite significant work on the regulation of eukaryotic transcription, the effect of DNA template sequence on RNA polymerase I (Pol I) transcription elongation remains unknown. In this study, we examined the effects of DNA sequence motifs on Pol I transcription elongation kinetics in vitro and in vivo. Specifically, we characterized how the spy rho-independent terminator motif from Escherichia coli directly affects Saccharomyces cerevisiae Pol I activity, demonstrating evolutionary conservation of sequence-specific effects on transcription. The insight gained from this analysis led to the identification of a homologous sequence in the ribosomal DNA of S. cerevisiae We then used native elongating transcript sequencing (NETSeq) to determine whether Pol I encounters pause-inducing sequences in vivo. We found hundreds of positions within the ribosomal DNA (rDNA) that reproducibly induce pausing in vivo. We also observed significantly lower Pol I occupancy at G residues in the rDNA, independent of other sequence context, indicating differential nucleotide incorporation rates for Pol I in vivo. These data demonstrate that DNA template sequence elements directly influence Pol I transcription elongation. Furthermore, we have developed the necessary experimental and analytical methods to investigate these perturbations in living cells going forward.
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Proximity-CLIP provides a snapshot of protein-occupied RNA elements in subcellular compartments. Nat Methods 2018; 15:1074-1082. [PMID: 30478324 PMCID: PMC6289640 DOI: 10.1038/s41592-018-0220-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 09/25/2018] [Indexed: 12/22/2022]
Abstract
Methods to systematically study subcellular RNA localization are limited and lagging behind proteomic tools. Here, we combined APEX2-mediated proximity biotinylation of proteins with photoactivatable ribonucleoside-enhanced crosslinking to simultaneously profile the proteome, as well as the transcriptome bound by RNA-binding proteins in any given subcellular compartment. Our approach is fractionation-independent and enables to study the localization of RNA processing intermediates, as well as the identification of regulatory RNA cis-acting elements occupied by proteins in a cellular compartment-specific manner. We applied Proximity-CLIP to study RNA and protein in the nucleus, cytoplasm and at cell-cell interfaces. Among other insights, we observed frequent transcriptional readthrough continuing for several kilobases downstream of the canonical cleavage and polyadenylation site and a differential RBP occupancy pattern for mRNAs in the nucleus and cytoplasm. Surprisingly, mRNAs localized to cell-cell interfaces often encoded regulatory proteins and contained protein-occupied CUG sequence elements in their 3’ untranslated region.
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Immediate-Early Promoter-Driven Transgenic Reporter System for Neuroethological Research in a Hemimetabolous Insect. eNeuro 2018; 5:eN-MNT-0061-18. [PMID: 30225346 PMCID: PMC6140108 DOI: 10.1523/eneuro.0061-18.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 07/11/2018] [Accepted: 07/20/2018] [Indexed: 01/04/2023] Open
Abstract
Genes expressed in response to increased neuronal activity are widely used as activity markers in recent behavioral neuroscience. In the present study, we established transgenic reporter system for whole-brain activity mapping in the two-spotted cricket Gryllus bimaculatus, a hemimetabolous insect used in neuroethology and behavioral ecology. In the cricket brain, a homolog of early growth response-1 (Gryllus egr-B) was rapidly induced as an immediate-early gene (IEG) in response to neuronal hyperexcitability. The upstream genomic fragment of Gryllus egr-B contains potential binding sites for transcription factors regulated by various intracellular signaling pathways, as well as core promoter elements conserved across insect/crustacean egr-B homologs. Using the upstream genomic fragment of Gryllus egr-B, we established an IEG promoter-driven transgenic reporter system in the cricket. In the brain of transgenic crickets, the reporter gene (a nuclear-targeted destabilized EYFP) was induced in response to neuronal hyperexcitability. Inducible expression of reporter protein was detected in almost all neurons after neuronal hyperexcitability. Using our novel reporter system, we successfully detected neuronal activation evoked by feeding in the cricket brain. Our IEG promoter-driven activity reporting system allows us to visualize behaviorally relevant neural circuits at cellular resolution in the cricket brain.
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Wang J, Zhao Y, Zhou X, Hiebert SW, Liu Q, Shyr Y. Nascent RNA sequencing analysis provides insights into enhancer-mediated gene regulation. BMC Genomics 2018; 19:633. [PMID: 30139328 PMCID: PMC6107967 DOI: 10.1186/s12864-018-5016-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 08/14/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Enhancers are distal cis-regulatory elements that control gene expression. Despite an increasing appreciation of the importance of enhancers in cellular function and disease, our knowledge of enhancer-regulated transcription is very limited. Nascent RNA sequencing technologies, such as global nuclear run-on sequencing (GRO-seq) and precision run-on sequencing (PRO-seq), not only provide a direct and reliable measurement of enhancer activity, but also allow for quantifying transcription of enhancers and target genes simultaneously, making these technologies extremely useful for exploring enhancer-mediated regulation. RESULTS Nascent RNA sequencing analysis (NRSA) provides a comprehensive view of enhancer-mediated gene regulation. NRSA not only outperforms existing methods for enhancer identification, but also enables annotation and quantification of active enhancers, and prediction of their target genes. Furthermore, NRSA identifies functionally important enhancers by integrating 1) nascent transcriptional changes in enhancers and their target genes and 2) binding profiles from regulator(s) of interest. Applied to wildtype and histone deacetylase 3 (Hdac3) knockout mouse livers, NRSA showed that HDAC3 regulates RNA polymerase recruitment through both proximal (promoter) and distal (enhancer) regulatory elements. Integrating ChIP-seq with PRO-seq data, NRSA prioritized enhancers based on their potential contribution to mediating HDAC3 regulation. CONCLUSIONS NRSA will greatly facilitate the usage of nascent RNA sequencing techniques and accelerate the study of enhancer-mediated regulation.
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Affiliation(s)
- Jing Wang
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN USA
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN USA
| | - Yue Zhao
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN USA
| | - Xiaofan Zhou
- Department of Biological Science, Vanderbilt University, Nashville, TN USA
| | - Scott W. Hiebert
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN USA
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN USA
| | - Qi Liu
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN USA
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN USA
| | - Yu Shyr
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN USA
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN USA
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44
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Fitz J, Neumann T, Pavri R. Regulation of RNA polymerase II processivity by Spt5 is restricted to a narrow window during elongation. EMBO J 2018. [PMID: 29514850 PMCID: PMC5897773 DOI: 10.15252/embj.201797965] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spt5 is a highly conserved RNA polymerase II (Pol II)‐associated pausing and elongation factor. However, its impact on global elongation and Pol II processivity in mammalian cells has not been clarified. Here, we show that depleting Spt5 in mouse embryonic fibroblasts (MEFs) does not cause global elongation defects or decreased elongation rates. Instead, in Spt5‐depleted cells, a fraction of Pol II molecules are dislodged during elongation, thus decreasing the number of Pol II complexes that complete the transcription cycle. Most strikingly, this decrease is restricted to a narrow window between 15 and 20 kb from the promoter, a distance which coincides with the stage where accelerating Pol II attains maximum elongation speed. Consequently, long genes show a greater dependency on Spt5 for optimal elongation efficiency and overall gene expression than short genes. We propose that an important role of Spt5 in mammalian elongation is to promote the processivity of those Pol II complexes that are transitioning toward maximum elongation speed 15–20 kb from the promoter.
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Affiliation(s)
- Johanna Fitz
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Tobias Neumann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Rushad Pavri
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
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45
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Azofeifa JG, Allen MA, Hendrix JR, Read T, Rubin JD, Dowell RD. Enhancer RNA profiling predicts transcription factor activity. Genome Res 2018; 28:334-344. [PMID: 29449408 PMCID: PMC5848612 DOI: 10.1101/gr.225755.117] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 01/24/2018] [Indexed: 12/18/2022]
Abstract
Transcription factors (TFs) exert their regulatory influence through the binding of enhancers, resulting in coordination of gene expression programs. Active enhancers are often characterized by the presence of short, unstable transcripts termed enhancer RNAs (eRNAs). While their function remains unclear, we demonstrate that eRNAs are a powerful readout of TF activity. We infer sites of eRNA origination across hundreds of publicly available nascent transcription data sets and show that eRNAs initiate from sites of TF binding. By quantifying the colocalization of TF binding motif instances and eRNA origins, we derive a simple statistic capable of inferring TF activity. In doing so, we uncover dozens of previously unexplored links between diverse stimuli and the TFs they affect.
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Affiliation(s)
- Joseph G Azofeifa
- Department of Computer Science, University of Colorado, Boulder, Colorado 80309, USA
- BioFrontiers Institute, University of Colorado, Boulder, Colorado 80309, USA
| | - Mary A Allen
- BioFrontiers Institute, University of Colorado, Boulder, Colorado 80309, USA
| | - Josephina R Hendrix
- Department of Computer Science, University of Colorado, Boulder, Colorado 80309, USA
- Department of Molecular, Cellular and Developmental Biology
| | - Timothy Read
- BioFrontiers Institute, University of Colorado, Boulder, Colorado 80309, USA
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Jonathan D Rubin
- Department of Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - Robin D Dowell
- Department of Computer Science, University of Colorado, Boulder, Colorado 80309, USA
- BioFrontiers Institute, University of Colorado, Boulder, Colorado 80309, USA
- Department of Molecular, Cellular and Developmental Biology
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46
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Guo X, Myasnikov AG, Chen J, Crucifix C, Papai G, Takacs M, Schultz P, Weixlbaumer A. Structural Basis for NusA Stabilized Transcriptional Pausing. Mol Cell 2018; 69:816-827.e4. [PMID: 29499136 PMCID: PMC5842316 DOI: 10.1016/j.molcel.2018.02.008] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/22/2018] [Accepted: 02/02/2018] [Indexed: 12/12/2022]
Abstract
Transcriptional pausing by RNA polymerases (RNAPs) is a key mechanism to regulate gene expression in all kingdoms of life and is a prerequisite for transcription termination. The essential bacterial transcription factor NusA stimulates both pausing and termination of transcription, thus playing a central role. Here, we report single-particle electron cryo-microscopy reconstructions of NusA bound to paused E. coli RNAP elongation complexes with and without a pause-enhancing hairpin in the RNA exit channel. The structures reveal four interactions between NusA and RNAP that suggest how NusA stimulates RNA folding, pausing, and termination. An asymmetric translocation intermediate of RNA and DNA converts the active site of the enzyme into an inactive state, providing a structural explanation for the inhibition of catalysis. Comparing RNAP at different stages of pausing provides insights on the dynamic nature of the process and the role of NusA as a regulatory factor.
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Affiliation(s)
- Xieyang Guo
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch Cedex, France; Université de Strasbourg, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale (Inserm), U964, 67404 Illkirch Cedex, France
| | - Alexander G Myasnikov
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch Cedex, France; Université de Strasbourg, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale (Inserm), U964, 67404 Illkirch Cedex, France
| | - James Chen
- The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Corinne Crucifix
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch Cedex, France; Université de Strasbourg, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale (Inserm), U964, 67404 Illkirch Cedex, France
| | - Gabor Papai
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch Cedex, France; Université de Strasbourg, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale (Inserm), U964, 67404 Illkirch Cedex, France
| | - Maria Takacs
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch Cedex, France; Université de Strasbourg, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale (Inserm), U964, 67404 Illkirch Cedex, France
| | - Patrick Schultz
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch Cedex, France; Université de Strasbourg, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale (Inserm), U964, 67404 Illkirch Cedex, France
| | - Albert Weixlbaumer
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67404 Illkirch Cedex, France; Université de Strasbourg, 67404 Illkirch Cedex, France; Centre National de la Recherche Scientifique (CNRS), UMR 7104, 67404 Illkirch Cedex, France; Institut National de la Santé et de la Recherche Médicale (Inserm), U964, 67404 Illkirch Cedex, France.
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Janardhan A, Kathera C, Darsi A, Ali W, He L, Yang Y, Luo L, Guo Z. Prominent role of histone lysine demethylases in cancer epigenetics and therapy. Oncotarget 2018; 9:34429-34448. [PMID: 30344952 PMCID: PMC6188137 DOI: 10.18632/oncotarget.24319] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 12/04/2017] [Indexed: 12/14/2022] Open
Abstract
Protein methylation has an important role in the regulation of chromatin, gene expression and regulation. The protein methyl transferases are genetically altered in various human cancers. The enzymes that remove histone methylation have led to increased awareness of protein interactions as potential drug targets. Specifically, Lysine Specific Demethylases (LSD) removes methylated histone H3 lysine 4 (H3K4) and H3 lysine 9 (H3K9) through formaldehyde-generating oxidation. It has been reported that LSD1 and its downstream targets are involved in tumor-cell growth and metastasis. Functional studies of LSD1 indicate that it regulates activation and inhibition of gene transcription in the nucleus. Here we made a discussion about the summary of histone lysine demethylase and their functions in various human cancers.
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Affiliation(s)
- Avilala Janardhan
- The No. 7 People's Hospital of Changzhou, Changzhou, China.,Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chandrasekhar Kathera
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Amrutha Darsi
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Wajid Ali
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Lingfeng He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Yanhua Yang
- The No. 7 People's Hospital of Changzhou, Changzhou, China
| | - Libo Luo
- The No. 7 People's Hospital of Changzhou, Changzhou, China
| | - Zhigang Guo
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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48
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Krause MW, Love DC, Ghosh SK, Wang P, Yun S, Fukushige T, Hanover JA. Nutrient-Driven O-GlcNAcylation at Promoters Impacts Genome-Wide RNA Pol II Distribution. Front Endocrinol (Lausanne) 2018; 9:521. [PMID: 30250452 PMCID: PMC6139338 DOI: 10.3389/fendo.2018.00521] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/21/2018] [Indexed: 01/07/2023] Open
Abstract
Nutrient-driven O-GlcNAcylation has been linked to epigenetic regulation of gene expression in metazoans. In C. elegans, O-GlcNAc marks the promoters of over 800 developmental, metabolic, and stress-related genes; these O-GlcNAc marked genes show a strong 5', promoter-proximal bias in the distribution of RNA Polymerase II (Pol II). In response to starvation or feeding, the steady state distribution of O-GlcNAc at promoters remain nearly constant presumably due to dynamic cycling mediated by the transferase OGT-1 and the O-GlcNAcase OGA-1. However, in viable mutants lacking either of these enzymes of O-GlcNAc metabolism, the nutrient-responsive GlcNAcylation of promoters is dramatically altered. Blocked O-GlcNAc cycling leads to a striking nutrient-dependent accumulation of O-GlcNAc on RNA Pol II. O-GlcNAc cycling mutants also show an exaggerated, nutrient-responsive redistribution of promoter-proximal RNA Pol II isoforms and extensive transcriptional deregulation. Our findings suggest a complex interplay between the O-GlcNAc modification at promoters, the kinase-dependent "CTD-code," and co-factors regulating RNA Pol II dynamics. Nutrient-responsive O-GlcNAc cycling may buffer the transcriptional apparatus from dramatic swings in nutrient availability by modulating promoter activity to meet metabolic and developmental needs.
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Affiliation(s)
- Michael W. Krause
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Dona C. Love
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Salil K. Ghosh
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Peng Wang
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Sijung Yun
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Tetsunari Fukushige
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - John A. Hanover
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: John A. Hanover
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49
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McKinlay A, Podicheti R, Wendte JM, Cocklin R, Rusch DB. RNA polymerases IV and V influence the 3' boundaries of Polymerase II transcription units in Arabidopsis. RNA Biol 2017; 15:269-279. [PMID: 29199514 DOI: 10.1080/15476286.2017.1409930] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Nuclear multisubunit RNA polymerases IV and V (Pol IV and Pol V) evolved in plants as specialized forms of Pol II. Their functions are best understood in the context of RNA-directed DNA methylation (RdDM), a process in which Pol IV-dependent 24 nt siRNAs direct the de novo cytosine methylation of regions transcribed by Pol V. Pol V has additional functions, independent of Pol IV and 24 nt siRNA biogenesis, in maintaining the repression of transposons and genomic repeats whose silencing depends on maintenance cytosine methylation. Here we report that Pol IV and Pol V play unexpected roles in defining the 3' boundaries of Pol II transcription units. Nuclear run-on assays reveal that in the absence of Pol IV or Pol V, Pol II occupancy downstream of poly A sites increases for approximately 12% of protein-coding genes. This effect is most pronounced for convergently transcribed gene pairs. Although Pols IV and V are detected near transcript ends of the affected Pol II - transcribed genes, their role in limiting Pol II read-through is independent of siRNA biogenesis or cytosine methylation for the majority of these genes. Interestingly, we observed that splicing was less efficient in pol IV or pol V mutant plants, compared to wild-type plants, suggesting that Pol IV or Pol V might affect pre-mRNA processing. We speculate that Pols IV and V (and/or their associated factors) play roles in Pol II transcription termination and pre-mRNA splicing by influencing polymerase elongation rates and/or release at collision sites for convergent genes.
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Affiliation(s)
- Anastasia McKinlay
- a Department of Biology , Indiana University , Bloomington , Indiana , USA
| | - Ram Podicheti
- b Center for Genomics and Bioinformatics, Indiana University , Bloomington , Indiana , USA.,c School of Informatics and Computing, Indiana University , Bloomington , IN , USA
| | - Jered M Wendte
- a Department of Biology , Indiana University , Bloomington , Indiana , USA
| | - Ross Cocklin
- a Department of Biology , Indiana University , Bloomington , Indiana , USA.,d Howard Hughes Medical Institute, Indiana University , Bloomington , Indiana
| | - Douglas B Rusch
- b Center for Genomics and Bioinformatics, Indiana University , Bloomington , Indiana , USA
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50
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CBP Regulates Recruitment and Release of Promoter-Proximal RNA Polymerase II. Mol Cell 2017; 68:491-503.e5. [PMID: 29056321 DOI: 10.1016/j.molcel.2017.09.031] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 07/13/2017] [Accepted: 09/21/2017] [Indexed: 11/21/2022]
Abstract
Transcription activation involves RNA polymerase II (Pol II) recruitment and release from the promoter into productive elongation, but how specific chromatin regulators control these steps is unclear. Here, we identify a novel activity of the histone acetyltransferase p300/CREB-binding protein (CBP) in regulating promoter-proximal paused Pol II. We find that Drosophila CBP inhibition results in "dribbling" of Pol II from the pause site to positions further downstream but impedes transcription through the +1 nucleosome genome-wide. Promoters strongly occupied by CBP and GAGA factor have high levels of paused Pol II, a unique chromatin signature, and are highly expressed regardless of cell type. Interestingly, CBP activity is rate limiting for Pol II recruitment to these highly paused promoters through an interaction with TFIIB but for transit into elongation by histone acetylation at other genes. Thus, CBP directly stimulates both Pol II recruitment and the ability to traverse the first nucleosome, thereby promoting transcription of most genes.
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