51
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Tettey TT, Gao X, Shao W, Li H, Story BA, Chitsazan AD, Glaser RL, Goode ZH, Seidel CW, Conaway RC, Zeitlinger J, Blanchette M, Conaway JW. A Role for FACT in RNA Polymerase II Promoter-Proximal Pausing. Cell Rep 2020; 27:3770-3779.e7. [PMID: 31242411 DOI: 10.1016/j.celrep.2019.05.099] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 04/22/2019] [Accepted: 05/24/2019] [Indexed: 01/06/2023] Open
Abstract
FACT (facilitates chromatin transcription) is an evolutionarily conserved histone chaperone that was initially identified as an activity capable of promoting RNA polymerase II (Pol II) transcription through nucleosomes in vitro. In this report, we describe a global analysis of FACT function in Pol II transcription in Drosophila. We present evidence that loss of FACT has a dramatic impact on Pol II elongation-coupled processes including histone H3 lysine 4 (H3K4) and H3K36 methylation, consistent with a role for FACT in coordinating histone modification and chromatin architecture during Pol II transcription. Importantly, we identify a role for FACT in the maintenance of promoter-proximal Pol II pausing, a key step in transcription activation in higher eukaryotes. These findings bring to light a broader role for FACT in the regulation of Pol II transcription.
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Affiliation(s)
- Theophilus T Tettey
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA; The Open University, Walton Hall, Milton Keynes, Buckinghamshire MK7 6AA, UK
| | - Xin Gao
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Wanqing Shao
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Hua Li
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Benjamin A Story
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Alex D Chitsazan
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Robert L Glaser
- Wadsworth Center, New York State Department of Health, PO Box 509, Albany, NY 12201, USA
| | - Zach H Goode
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Christopher W Seidel
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Ronald C Conaway
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Julia Zeitlinger
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA; Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Marco Blanchette
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA
| | - Joan W Conaway
- Stowers Institute for Medical Research, 1000 E 50th St, Kansas City, MO 64110, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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52
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Wachs AS, Bohne J. Two sides of the same medal: Noncoding mutations reveal new pathological mechanisms and insights into the regulation of gene expression. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1616. [PMID: 32633083 DOI: 10.1002/wrna.1616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 12/22/2022]
Abstract
Noncoding sequences constitute the major part of the human genome and also of pre-mRNAs. Single nucleotide variants in these regions are often overlooked, but may be responsible for much of the variation of phenotypes observed. Mutations in the noncoding part of pre-mRNAs often reveal new and meaningful insights into the regulation of cellular gene expression. Thus, the mechanistic analysis of the pathological mechanism of such mutations will both foster a deeper understanding of the disease and the underlying cellular pathways. Even synonymous mutations can cause diseases, since the primary mRNA sequence not only encodes amino acids, but also encrypts information on RNA-binding proteins and secondary structure. In fact, the RNA sequence directs assembly of a specific mRNP complex, which in turn dictates the fate of the mRNA or regulates its biogenesis. The accumulation of genomic sequence information is increasing at a rapid pace. However, much of the diversity uncovered may not explain the phenotype of a certain syndrome or disease. For this reason, we also emphasize the value of mechanistic studies on pathological mechanisms being complementary to genome-wide studies and bioinformatic approaches. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Processing > 3' End Processing RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Amelie S Wachs
- Institute of Virology, Hannover Medical School, Hanover, Germany
| | - Jens Bohne
- Institute of Virology, Hannover Medical School, Hanover, Germany
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53
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Cheng Q, Xiao H, Xiong Q. Conserved exitrons of FLAGELLIN-SENSING 2 (FLS2) across dicot plants and their functions. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 296:110507. [PMID: 32540022 DOI: 10.1016/j.plantsci.2020.110507] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 03/20/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
The alternative splicing of pattern recognition receptor genes regulates immune signalling in mammals, but in plants its role is still unknown. Here, we detected alternatively spliced introns (exitrons) in the first annotated exons of FLAGELLIN-SENSING 2 (FLS2) genes in all the examined dicot plants across nine families. The 5' splice site (SS) regions were conserved and with rare synonymous substitutions. Point mutations and gene swaps indicated that the position and efficiency of exitron splicing primarily depended on the nucleotide sequences of FLS2 genes. Single-nucleotide mutations in the invariable codon carrying 5' SS dramatically altered the accumulation of poplar and tomato FLS2 transcripts, indicating the 5'-proximal exitrons of FLS2 function as stimulatory introns on gene expression. The 3' SSs of exitrons are diverse and can be changed by 1-2 nucleotide mutations in Salicaceae FLS2. The alternative transcripts (ATs) of poplar and tobacco FLS2, which encode small secreted proteins, were specifically induced by flg22, and one such AT from tobacco FLS2 suppressed flg22-induced response. Our results indicated that the exitrons of FLS2 genes regulate the accumulation of transcripts by an intron mediated enhancement (IME) mechanism and some ATs have the potential to encode suppressors for FLS2 pathway.
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Affiliation(s)
- Qiang Cheng
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China.
| | - Hongju Xiao
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Qin Xiong
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
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54
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Davidson L, Francis L, Cordiner RA, Eaton JD, Estell C, Macias S, Cáceres JF, West S. Rapid Depletion of DIS3, EXOSC10, or XRN2 Reveals the Immediate Impact of Exoribonucleolysis on Nuclear RNA Metabolism and Transcriptional Control. Cell Rep 2020; 26:2779-2791.e5. [PMID: 30840897 PMCID: PMC6403362 DOI: 10.1016/j.celrep.2019.02.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/09/2019] [Accepted: 02/04/2019] [Indexed: 12/26/2022] Open
Abstract
Cell-based studies of human ribonucleases traditionally rely on methods that deplete proteins slowly. We engineered cells in which the 3′→5′ exoribonucleases of the exosome complex, DIS3 and EXOSC10, can be rapidly eliminated to assess their immediate roles in nuclear RNA biology. The loss of DIS3 has the greatest impact, causing the substantial accumulation of thousands of transcripts within 60 min. These transcripts include enhancer RNAs, promoter upstream transcripts (PROMPTs), and products of premature cleavage and polyadenylation (PCPA). These transcripts are unaffected by the rapid loss of EXOSC10, suggesting that they are rarely targeted to it. More direct detection of EXOSC10-bound transcripts revealed its substrates to prominently include short 3′ extended ribosomal and small nucleolar RNAs. Finally, the 5′→3′ exoribonuclease, XRN2, has little activity on exosome substrates, but its elimination uncovers different mechanisms for the early termination of transcription from protein-coding gene promoters. Engineered human cells for rapid inducible degradation of EXOSC10 and DIS3 DIS3 degrades the majority of nuclear exosome substrates Direct targets of EXOSC10 include ribosomal and small nucleolar RNAs XRN2 has little activity on exosome substrates
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Affiliation(s)
- Lee Davidson
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Laura Francis
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Ross A Cordiner
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Joshua D Eaton
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Chris Estell
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK
| | - Sara Macias
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Javier F Cáceres
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Steven West
- The Living Systems Institute, University of Exeter, Stocker Rd, Exeter EX4 4QD, UK.
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55
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Thomas QA, Ard R, Liu J, Li B, Wang J, Pelechano V, Marquardt S. Transcript isoform sequencing reveals widespread promoter-proximal transcriptional termination in Arabidopsis. Nat Commun 2020; 11:2589. [PMID: 32444691 PMCID: PMC7244574 DOI: 10.1038/s41467-020-16390-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 04/29/2020] [Indexed: 01/22/2023] Open
Abstract
RNA polymerase II (RNAPII) transcription converts the DNA sequence of a single gene into multiple transcript isoforms that may carry alternative functions. Gene isoforms result from variable transcription start sites (TSSs) at the beginning and polyadenylation sites (PASs) at the end of transcripts. How alternative TSSs relate to variable PASs is poorly understood. Here, we identify both ends of RNA molecules in Arabidopsis thaliana by transcription isoform sequencing (TIF-seq) and report four transcript isoforms per expressed gene. While intragenic initiation represents a large source of regulated isoform diversity, we observe that ~14% of expressed genes generate relatively unstable short promoter-proximal RNAs (sppRNAs) from nascent transcript cleavage and polyadenylation shortly after initiation. The location of sppRNAs correlates with the position of promoter-proximal RNAPII stalling, indicating that large pools of promoter-stalled RNAPII may engage in transcriptional termination. We propose that promoter-proximal RNAPII stalling-linked to premature transcriptional termination may represent a checkpoint that governs plant gene expression.
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Affiliation(s)
- Quentin Angelo Thomas
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Ryan Ard
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Jinghan Liu
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Bingnan Li
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Jingwen Wang
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Sebastian Marquardt
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark.
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56
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Krooss S, Werwitzke S, Kopp J, Rovai A, Varnholt D, Wachs AS, Goyenvalle A, Aarstma-Rus A, Ott M, Tiede A, Langemeier J, Bohne J. Pathological mechanism and antisense oligonucleotide-mediated rescue of a non-coding variant suppressing factor 9 RNA biogenesis leading to hemophilia B. PLoS Genet 2020; 16:e1008690. [PMID: 32267853 PMCID: PMC7141619 DOI: 10.1371/journal.pgen.1008690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 02/22/2020] [Indexed: 01/25/2023] Open
Abstract
Loss-of-function mutations in the human coagulation factor 9 (F9) gene lead to hemophilia B. Here, we dissected the consequences and the pathomechanism of a non-coding mutation (c.2545A>G) in the F9 3’ untranslated region. Using wild type and mutant factor IX (FIX) minigenes we revealed that the mutation leads to reduced F9 mRNA and FIX protein levels and to lower coagulation activity of cell culture supernatants. The phenotype could not be compensated by increased transcription. The pathomechanism comprises the de novo creation of a binding site for the spliceosomal component U1snRNP, which is able to suppress the nearby F9 poly(A) site. This second, splicing-independent function of U1snRNP was discovered previously and blockade of U1snRNP restored mutant F9 mRNA expression. In addition, we explored the vice versa approach and masked the mutation by antisense oligonucleotides resulting in significantly increased F9 mRNA expression and coagulation activity. This treatment may transform the moderate/severe hemophilia B into a mild or subclinical form in the patients. This antisense based strategy is applicable to other mutations in untranslated regions creating deleterious binding sites for cellular proteins. The elucidation of the pathomechanisms of non-coding variants yields important insights into diseases as well as cellular processes causing the defect. Although these variants may account for the majority of phenotypic variation, only a minority of them can be explained mechanistically. The human coagulation factor 9 3’ UTR variant described here converts a non-essential sequence motif into a U1snRNP-binding site with deleterious effects on RNA 3’ end processing at the nearby poly(A) site. Poly(A) site suppression by U1snRNP was described before and it normally protects cellular mRNAs from premature termination. However, if misled by creation of a U1 site close the authentic poly(A) site as in the F9 3’ UTR, this nuclear surveillance mechanism results in the opposite. Since recognition by U1snRNP depends on sequence complementarity we were able to use antisense oligonucleotides to mask the mutant site and partially restored F9 mRNA levels. This antisense based strategy may be applicable to other variants in untranslated regions, which create deleterious binding sites for cellular proteins.
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Affiliation(s)
- Simon Krooss
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School and Twincore Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Sonja Werwitzke
- Clinic of Hematology, Oncology and Hemostaseology, Hannover Medical School, Hannover, Germany
| | - Johannes Kopp
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Alice Rovai
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School and Twincore Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Dirk Varnholt
- Clinic of Hematology, Oncology and Hemostaseology, Hannover Medical School, Hannover, Germany
| | - Amelie S. Wachs
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | | | | | - Michael Ott
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School and Twincore Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Andreas Tiede
- Clinic of Hematology, Oncology and Hemostaseology, Hannover Medical School, Hannover, Germany
| | - Jörg Langemeier
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Pediatric Intensive Care Unit, Children’s Hospital Bielefeld, Germany
- * E-mail: (JL); (JB)
| | - Jens Bohne
- Institute of Virology, Hannover Medical School, Hannover, Germany
- * E-mail: (JL); (JB)
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Abstract
Targeting the function of MYC oncoproteins holds the promise of achieving conceptually new and effective anticancer therapies that can be applied to a broad range of tumors. The nature of the target however—a broadly, possibly universally acting transcription factor that has no enzymatic activity and is largely unstructured unless complexed with partner proteins—has so far defied the development of clinically applicable MYC-directed therapies. At the same time, lingering questions about exactly which functions of MYC proteins account for their pervasive oncogenic role in human tumors and need to be targeted have prevented the development of effective therapies using surrogate targets that act in critical MYC-dependent pathways. In this review, we therefore argue that rigorous testing of critical oncogenic functions and protein/protein interactions and new chemical approaches to target them are necessary to successfully eradicate MYC-driven tumors.
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Affiliation(s)
- Elmar Wolf
- Department of Biochemistry and Molecular Biology, Theodor Boveri Institute, University of Würzburg, 97074 Würzburg, Germany;,
| | - Martin Eilers
- Department of Biochemistry and Molecular Biology, Theodor Boveri Institute, University of Würzburg, 97074 Würzburg, Germany;,
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58
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Localized Inhibition of Protein Phosphatase 1 by NUAK1 Promotes Spliceosome Activity and Reveals a MYC-Sensitive Feedback Control of Transcription. Mol Cell 2020; 77:1322-1339.e11. [PMID: 32006464 PMCID: PMC7086158 DOI: 10.1016/j.molcel.2020.01.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 12/09/2019] [Accepted: 01/07/2020] [Indexed: 01/19/2023]
Abstract
Deregulated expression of MYC induces a dependence on the NUAK1 kinase, but the molecular mechanisms underlying this dependence have not been fully clarified. Here, we show that NUAK1 is a predominantly nuclear protein that associates with a network of nuclear protein phosphatase 1 (PP1) interactors and that PNUTS, a nuclear regulatory subunit of PP1, is phosphorylated by NUAK1. Both NUAK1 and PNUTS associate with the splicing machinery. Inhibition of NUAK1 abolishes chromatin association of PNUTS, reduces spliceosome activity, and suppresses nascent RNA synthesis. Activation of MYC does not bypass the requirement for NUAK1 for spliceosome activity but significantly attenuates transcription inhibition. Consequently, NUAK1 inhibition in MYC-transformed cells induces global accumulation of RNAPII both at the pause site and at the first exon-intron boundary but does not increase mRNA synthesis. We suggest that NUAK1 inhibition in the presence of deregulated MYC traps non-productive RNAPII because of the absence of correctly assembled spliceosomes. Nuclear NUAK1 associates with PP1 and phosphorylates its targeting subunit PNUTS NUAK1, PP1, and PNUTS form a trimer that associates with the splicing machinery Inhibition of NUAK1 reduces spliceosome activity and nascent RNA synthesis When MYC is deregulated, NUAK1 inhibition traps RNAPII at the intron-exon boundary
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59
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Kainov YA, Makeyev EV. A transcriptome-wide antitermination mechanism sustaining identity of embryonic stem cells. Nat Commun 2020; 11:361. [PMID: 31953406 PMCID: PMC6969169 DOI: 10.1038/s41467-019-14204-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 12/11/2019] [Indexed: 11/29/2022] Open
Abstract
Eukaryotic gene expression relies on extensive crosstalk between transcription and RNA processing. Changes in this composite regulation network may provide an important means for shaping cell type-specific transcriptomes. Here we show that the RNA-associated protein Srrt/Ars2 sustains embryonic stem cell (ESC) identity by preventing premature termination of numerous transcripts at cryptic cleavage/polyadenylation sites in first introns. Srrt interacts with the nuclear cap-binding complex and facilitates recruitment of the spliceosome component U1 snRNP to cognate intronic positions. At least in some cases, U1 recruited in this manner inhibits downstream cleavage/polyadenylation events through a splicing-independent mechanism called telescripting. We further provide evidence that the naturally high expression of Srrt in ESCs offsets deleterious effects of retrotransposable sequences accumulating in its targets. Our work identifies Srrt as a molecular guardian of the pluripotent cell state. Besides its role in splicing, U1 snRNP can suppress pre-mRNA cleavage and polyadenylation. The authors show that the nuclear cap-binding complex component Srrt/Ars2 maintains embryonic stem cell identity by promoting U1 recruitment to first introns and preventing premature termination of multiple transcripts.
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Affiliation(s)
- Yaroslav A Kainov
- Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
| | - Eugene V Makeyev
- Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK.
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60
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Oh JM, Venters CC, Di C, Pinto AM, Wan L, Younis I, Cai Z, Arai C, So BR, Duan J, Dreyfuss G. U1 snRNP regulates cancer cell migration and invasion in vitro. Nat Commun 2020; 11:1. [PMID: 31911652 PMCID: PMC6946686 DOI: 10.1038/s41467-019-13993-7] [Citation(s) in RCA: 3037] [Impact Index Per Article: 759.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
Stimulated cells and cancer cells have widespread shortening of mRNA 3'-untranslated regions (3'UTRs) and switches to shorter mRNA isoforms due to usage of more proximal polyadenylation signals (PASs) in introns and last exons. U1 snRNP (U1), vertebrates' most abundant non-coding (spliceosomal) small nuclear RNA, silences proximal PASs and its inhibition with antisense morpholino oligonucleotides (U1 AMO) triggers widespread premature transcription termination and mRNA shortening. Here we show that low U1 AMO doses increase cancer cells' migration and invasion in vitro by up to 500%, whereas U1 over-expression has the opposite effect. In addition to 3'UTR length, numerous transcriptome changes that could contribute to this phenotype are observed, including alternative splicing, and mRNA expression levels of proto-oncogenes and tumor suppressors. These findings reveal an unexpected role for U1 homeostasis (available U1 relative to transcription) in oncogenic and activated cell states, and suggest U1 as a potential target for their modulation.
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Affiliation(s)
- Jung-Min Oh
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Christopher C Venters
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Chao Di
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Anna Maria Pinto
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Lili Wan
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Ihab Younis
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Zhiqiang Cai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Chie Arai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Byung Ran So
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Jingqi Duan
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Gideon Dreyfuss
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA.
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61
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Wissink EM, Vihervaara A, Tippens ND, Lis JT. Nascent RNA analyses: tracking transcription and its regulation. Nat Rev Genet 2019; 20:705-723. [PMID: 31399713 PMCID: PMC6858503 DOI: 10.1038/s41576-019-0159-6] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2019] [Indexed: 12/19/2022]
Abstract
The programmes that direct an organism's development and maintenance are encoded in its genome. Decoding of this information begins with regulated transcription of genomic DNA into RNA. Although transcription and its control can be tracked indirectly by measuring stable RNAs, it is only by directly measuring nascent RNAs that the immediate regulatory changes in response to developmental, environmental, disease and metabolic signals are revealed. Multiple complementary methods have been developed to quantitatively track nascent transcription genome-wide at nucleotide resolution, all of which have contributed novel insights into the mechanisms of gene regulation and transcription-coupled RNA processing. Here we critically evaluate the array of strategies used for investigating nascent transcription and discuss the recent conceptual advances they have provided.
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Affiliation(s)
- Erin M Wissink
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Anniina Vihervaara
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Nathaniel D Tippens
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
- Tri-Institutional Training Program in Computational Biology and Medicine, New York, NY, USA
| | - John T Lis
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
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62
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Abstract
The numerous quality control pathways that target defective ribonucleic acids (RNAs) for degradation play key roles in shaping mammalian transcriptomes and preventing disease. These pathways monitor most steps in the biogenesis of both noncoding RNAs (ncRNAs) and protein-coding messenger RNAs (mRNAs), degrading ncRNAs that fail to form functional complexes with one or more proteins and eliminating mRNAs that encode abnormal, potentially toxic proteins. Mutations in components of diverse RNA surveillance pathways manifest as disease. Some mutations are characterized by increased interferon production, suggesting that a major role of these pathways is to prevent aberrant cellular RNAs from being recognized as "non-self." Other mutations are common in cancer, or result in developmental defects, revealing the importance of RNA surveillance to cell and organismal function.
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Affiliation(s)
- Sandra L Wolin
- RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.
- Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA
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63
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LeRoy G, Oksuz O, Descostes N, Aoi Y, Ganai RA, Kara HO, Yu JR, Lee CH, Stafford J, Shilatifard A, Reinberg D. LEDGF and HDGF2 relieve the nucleosome-induced barrier to transcription in differentiated cells. SCIENCE ADVANCES 2019; 5:eaay3068. [PMID: 31616795 PMCID: PMC6774727 DOI: 10.1126/sciadv.aay3068] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/05/2019] [Indexed: 05/25/2023]
Abstract
FACT (facilitates chromatin transcription) is a protein complex that allows RNA polymerase II (RNAPII) to overcome the nucleosome-induced barrier to transcription. While abundant in undifferentiated cells and many cancers, FACT is not abundant or is absent in most tissues. Therefore, we screened for additional proteins that might replace FACT upon differentiation. We identified two proteins, lens epithelium-derived growth factor (LEDGF) and hepatoma-derived growth factor 2 (HDGF2), each containing two high mobility group A (HMGA)-like AT-hooks and a methyl-lysine reading Pro-Trp-Trp-Pro (PWWP) domain that binds to H3K36me2 and H3K36me3.LEDGF and HDGF2 colocalize with H3K36me2/3 at genomic regions containing active genes. In myoblasts, LEDGF and HDGF2 are enriched on most active genes. Upon differentiation to myotubes, LEDGF levels decrease, while HDGF2 levels are maintained. Moreover, HDGF2 is required for their proper expression. HDGF2 knockout myoblasts exhibit an accumulation of paused RNAPII within the transcribed region of many HDGF2 target genes, indicating a defect in early elongation.
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Affiliation(s)
- Gary LeRoy
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Ozgur Oksuz
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Nicolas Descostes
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
- EMBL Rome, Adriano Buzzati-Traverso Campus, Via Ramarini 32, 00015 Monterotondo (RM), Italy
| | - Yuki Aoi
- Department of Biochemistry and Molecular Genetics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Rais A. Ganai
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Havva Ortabozkoyun Kara
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Jia-Ray Yu
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Chul-Hwan Lee
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - James Stafford
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Ali Shilatifard
- Department of Biochemistry and Molecular Genetics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Danny Reinberg
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
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64
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Tatomer DC, Elrod ND, Liang D, Xiao MS, Jiang JZ, Jonathan M, Huang KL, Wagner EJ, Cherry S, Wilusz JE. The Integrator complex cleaves nascent mRNAs to attenuate transcription. Genes Dev 2019; 33:1525-1538. [PMID: 31530651 PMCID: PMC6824465 DOI: 10.1101/gad.330167.119] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/09/2019] [Indexed: 12/13/2022]
Abstract
In this study, Tatomer et al. systematically identify regulators of inducible gene expression; they performed high-throughput RNAi screening of the Drosophila Metallothionein A (MtnA) promoter, which showed that the Integrator complex attenuates MtnA transcription during copper stress. Their findings suggest that attenuation via Integrator cleavage limits production of many full-length mRNAs, allowing precise control of transcription outputs. Cellular homeostasis requires transcriptional outputs to be coordinated, and many events post-transcription initiation can dictate the levels and functions of mature transcripts. To systematically identify regulators of inducible gene expression, we performed high-throughput RNAi screening of the Drosophila Metallothionein A (MtnA) promoter. This revealed that the Integrator complex, which has a well-established role in 3′ end processing of small nuclear RNAs (snRNAs), attenuates MtnA transcription during copper stress. Integrator complex subunit 11 (IntS11) endonucleolytically cleaves MtnA transcripts, resulting in premature transcription termination and degradation of the nascent RNAs by the RNA exosome, a complex also identified in the screen. Using RNA-seq, we then identified >400 additional Drosophila protein-coding genes whose expression increases upon Integrator depletion. We focused on a subset of these genes and confirmed that Integrator is bound to their 5′ ends and negatively regulates their transcription via IntS11 endonuclease activity. Many noncatalytic Integrator subunits, which are largely dispensable for snRNA processing, also have regulatory roles at these protein-coding genes, possibly by controlling Integrator recruitment or RNA polymerase II dynamics. Altogether, our results suggest that attenuation via Integrator cleavage limits production of many full-length mRNAs, allowing precise control of transcription outputs.
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Affiliation(s)
- Deirdre C Tatomer
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Nathan D Elrod
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas 77550, USA
| | - Dongming Liang
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Mei-Sheng Xiao
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Jeffrey Z Jiang
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Michael Jonathan
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Kai-Lieh Huang
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas 77550, USA
| | - Eric J Wagner
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas 77550, USA
| | - Sara Cherry
- Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Jeremy E Wilusz
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
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So BR, Di C, Cai Z, Venters CC, Guo J, Oh JM, Arai C, Dreyfuss G. A Complex of U1 snRNP with Cleavage and Polyadenylation Factors Controls Telescripting, Regulating mRNA Transcription in Human Cells. Mol Cell 2019; 76:590-599.e4. [PMID: 31522989 DOI: 10.1016/j.molcel.2019.08.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/25/2019] [Accepted: 08/02/2019] [Indexed: 11/27/2022]
Abstract
Full-length transcription in the majority of human genes depends on U1 snRNP (U1) to co-transcriptionally suppress transcription-terminating premature 3' end cleavage and polyadenylation (PCPA) from cryptic polyadenylation signals (PASs) in introns. However, the mechanism of this U1 activity, termed telescripting, is unknown. Here, we captured a complex, comprising U1 and CPA factors (U1-CPAFs), that binds intronic PASs and suppresses PCPA. U1-CPAFs are distinct from U1-spliceosomal complexes; they include CPA's three main subunits, CFIm, CPSF, and CstF; lack essential splicing factors; and associate with transcription elongation and mRNA export complexes. Telescripting requires U1:pre-mRNA base-pairing, which can be disrupted by U1 antisense oligonucleotide (U1 AMO), triggering PCPA. U1 AMO remodels U1-CPAFs, revealing changes, including recruitment of CPA-stimulating factors, that explain U1-CPAFs' switch from repressive to activated states. Our findings outline this U1 telescripting mechanism and demonstrate U1's unique role as central regulator of pre-mRNA processing and transcription.
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Affiliation(s)
- Byung Ran So
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Chao Di
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Zhiqiang Cai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Christopher C Venters
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Jiannan Guo
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Jung-Min Oh
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Chie Arai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Gideon Dreyfuss
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA.
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66
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Tang S, Patel A, Krause PR. Hidden regulation of herpes simplex virus 1 pre-mRNA splicing and polyadenylation by virally encoded immediate early gene ICP27. PLoS Pathog 2019; 15:e1007884. [PMID: 31206552 PMCID: PMC6597130 DOI: 10.1371/journal.ppat.1007884] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/27/2019] [Accepted: 06/03/2019] [Indexed: 12/23/2022] Open
Abstract
In contrast to human cells, very few HSV-1 genes are known to be spliced, although the same pre-mRNA processing machinery is shared. Here, through global analysis of splice junctions in cells infected with HSV-1 and an HSV-1 mutant virus with deletion of infectious cell culture protein 27 (ICP27), one of two viral immediate early (IE) genes essential for viral replication, we identify hundreds of novel alternative splice junctions mapping to both previously known HSV-1 spliced genes and previously unknown spliced genes, the majority of which alter the coding potential of viral genes. Quantitative and qualitative splicing efficiency analysis of these novel alternatively spliced genes based on RNA-Seq and RT-PCR reveals that splicing at these novel splice sites is efficient only when ICP27 is absent; while in wildtype HSV-1 infected cells, the splicing of these novel splice junctions is largely silenced in a gene/sequence specific manner, suggesting that ICP27 not only promotes accumulation of ICP27 targeted transcripts but also ensures correctness of the functional coding sequences through inhibition of alternative splicing. Furthermore, ICP27 toggles expression of ICP34.5, the major viral neurovirulence factor, through inhibition of splicing and activation of a proximal polyadenylation signal (PAS) in the newly identified intron, revealing a novel regulatory mechanism for expression of a viral gene. Thus, through the viral IE protein ICP27, HSV-1 co-opts both splicing and polyadenylation machinery to achieve optimal viral gene expression during lytic infection. On the other hand, during latent infection when ICP27 is absent, HSV-1 likely takes advantages of host splicing machinery to restrict expression of randomly activated antigenic viral genes to achieve immune evasion. Little is known regarding to how HSV, a large DNA virus and known to contain very few spliced genes, escapes host pre-mRNA splicing machinery. Here, by establishing a high throughput splice junction identification platform and quantitative analysis method to assess splicing efficiency based on high throughput data, we find that HSV-1 encodes hundreds of previously unknown alternative splice junctions; however, splicing of these novel spliced genes is largely silenced in wild-type HSV-1 infected cells, explaining why only very few spliced genes have been previously identified in HSV-1. Moreover, ICP27 is required for splicing inhibition and 3’ end formation of ICP34.5, the major viral neurovirulence factor and also the major target of latently expressed viral miRNAs. These findings not only fundamentally change the view of HSV gene structure, but also reveal a mechanism by which HSV employs host splicing and polyadenylation machineries to achieve optimal gene expression during acute infection and may also contribute to immune evasion during latency when ICP27 is not expressed.
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Affiliation(s)
- Shuang Tang
- Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, United States of America
- * E-mail: (ST); (PRK)
| | - Amita Patel
- Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, United States of America
| | - Philip R. Krause
- Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, United States of America
- * E-mail: (ST); (PRK)
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67
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Kamieniarz-Gdula K, Proudfoot NJ. Transcriptional Control by Premature Termination: A Forgotten Mechanism. Trends Genet 2019; 35:553-564. [PMID: 31213387 PMCID: PMC7471841 DOI: 10.1016/j.tig.2019.05.005] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/10/2019] [Accepted: 05/16/2019] [Indexed: 12/26/2022]
Abstract
The concept of early termination as an important means of transcriptional control has long been established. Even so, its role in metazoan gene expression is underappreciated. Recent technological advances provide novel insights into premature transcription termination (PTT). This process is frequent, widespread, and can occur close to the transcription start site (TSS), or within the gene body. Stable prematurely terminated transcripts contribute to the transcriptome as instances of alternative polyadenylation (APA). Independently of transcript stability and function, premature termination opposes the formation of full-length transcripts, thereby negatively regulating gene expression, especially of transcriptional regulators. Premature termination can be beneficial or harmful, depending on its context. As a result, multiple factors have evolved to control this process.
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Affiliation(s)
- Kinga Kamieniarz-Gdula
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK; Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland; Center for Advanced Technology, Adam Mickiewicz University, Umultowska 89c, 61-614 Poznań, Poland.
| | - Nick J Proudfoot
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
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68
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Abstract
In this review, Core et al. discuss the recent advances in our understanding of the early steps in Pol II transcription, highlighting the events and factors involved in the establishment and release of paused Pol II. They also discuss a number of unanswered questions about the regulation and function of Pol II pausing. Precise spatio–temporal control of gene activity is essential for organismal development, growth, and survival in a changing environment. Decisive steps in gene regulation involve the pausing of RNA polymerase II (Pol II) in early elongation, and the controlled release of paused polymerase into productive RNA synthesis. Here we describe the factors that enable pausing and the events that trigger Pol II release into the gene. We also discuss open questions in the field concerning the stability of paused Pol II, nucleosomes as obstacles to elongation, and potential roles of pausing in defining the precision and dynamics of gene expression.
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Affiliation(s)
- Leighton Core
- Department of Molecular and Cell Biology, Institute of Systems Genomics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Karen Adelman
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
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69
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Singh RN, Singh NN. A novel role of U1 snRNP: Splice site selection from a distance. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:634-642. [PMID: 31042550 DOI: 10.1016/j.bbagrm.2019.04.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 04/15/2019] [Accepted: 04/18/2019] [Indexed: 12/23/2022]
Abstract
Removal of introns by pre-mRNA splicing is fundamental to gene function in eukaryotes. However, understanding the mechanism by which exon-intron boundaries are defined remains a challenging endeavor. Published reports support that the recruitment of U1 snRNP at the 5'ss marked by GU dinucleotides defines the 5'ss as well as facilitates 3'ss recognition through cross-exon interactions. However, exceptions to this rule exist as U1 snRNP recruited away from the 5'ss retains the capability to define the splice site, where the cleavage takes place. Independent reports employing exon 7 of Survival Motor Neuron (SMN) genes suggest a long-distance effect of U1 snRNP on splice site selection upon U1 snRNP recruitment at target sequences with or without GU dinucleotides. These findings underscore that sequences distinct from the 5'ss may also impact exon definition if U1 snRNP is recruited to them through partial complementarity with the U1 snRNA. In this review we discuss the expanded role of U1 snRNP in splice-site selection due to U1 ability to be recruited at more sites than predicted solely based on GU dinucleotides.
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Affiliation(s)
- Ravindra N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States of America.
| | - Natalia N Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, United States of America
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70
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Kamieniarz-Gdula K, Gdula MR, Panser K, Nojima T, Monks J, Wiśniewski JR, Riepsaame J, Brockdorff N, Pauli A, Proudfoot NJ. Selective Roles of Vertebrate PCF11 in Premature and Full-Length Transcript Termination. Mol Cell 2019; 74:158-172.e9. [PMID: 30819644 PMCID: PMC6458999 DOI: 10.1016/j.molcel.2019.01.027] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/07/2018] [Accepted: 01/17/2019] [Indexed: 12/02/2022]
Abstract
The pervasive nature of RNA polymerase II (Pol II) transcription requires efficient termination. A key player in this process is the cleavage and polyadenylation (CPA) factor PCF11, which directly binds to the Pol II C-terminal domain and dismantles elongating Pol II from DNA in vitro. We demonstrate that PCF11-mediated termination is essential for vertebrate development. A range of genomic analyses, including mNET-seq, 3′ mRNA-seq, chromatin RNA-seq, and ChIP-seq, reveals that PCF11 enhances transcription termination and stimulates early polyadenylation genome-wide. PCF11 binds preferentially between closely spaced genes, where it prevents transcriptional interference and consequent gene downregulation. Notably, PCF11 is sub-stoichiometric to the CPA complex. Low levels of PCF11 are maintained by an auto-regulatory mechanism involving premature termination of its own transcript and are important for normal development. Both in human cell culture and during zebrafish development, PCF11 selectively attenuates the expression of other transcriptional regulators by premature CPA and termination. Human PCF11 enhances transcription termination and 3′ end processing, genome-wide PCF11 is substoichiometric to CPA complex due to autoregulation of its transcription PCF11 stimulates expression of closely spaced genes but attenuates other genes PCF11-mediated functions are conserved in vertebrates and essential in development
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Affiliation(s)
- Kinga Kamieniarz-Gdula
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
| | - Michal R Gdula
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Karin Panser
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Takayuki Nojima
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Joan Monks
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Jacek R Wiśniewski
- Biochemical Proteomics Group, Department of Proteomics and Signal Transduction, Max-Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Joey Riepsaame
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Neil Brockdorff
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Andrea Pauli
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
| | - Nick J Proudfoot
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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71
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Venters CC, Oh JM, Di C, So BR, Dreyfuss G. U1 snRNP Telescripting: Suppression of Premature Transcription Termination in Introns as a New Layer of Gene Regulation. Cold Spring Harb Perspect Biol 2019; 11:11/2/a032235. [PMID: 30709878 DOI: 10.1101/cshperspect.a032235] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent observations showed that nascent RNA polymerase II transcripts, pre-mRNAs, and noncoding RNAs are highly susceptible to premature 3'-end cleavage and polyadenylation (PCPA) from numerous intronic cryptic polyadenylation signals (PASs). The importance of this in gene regulation was not previously appreciated as PASs, despite their prevalence, were thought to be active in terminal exons at gene ends. Unexpectedly, antisense oligonucleotide interference with U1 snRNA base-pairing to 5' splice sites, which is necessary for U1 snRNP's (U1) function in splicing, caused widespread PCPA in metazoans. This uncovered U1's PCPA suppression activity, termed telescripting, as crucial for full-length transcription in thousands of vertebrate genes, providing a general role in transcription elongation control. Progressive intron-size expansion in metazoan evolution greatly increased PCPA vulnerability and dependence on U1 telescripting. We describe how these observations unfolded and discuss U1 telescripting's role in shaping the transcriptome.
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Affiliation(s)
- Christopher C Venters
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Jung-Min Oh
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Chao Di
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Byung Ran So
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Gideon Dreyfuss
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
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72
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Lloret-Llinares M, Karadoulama E, Chen Y, Wojenski LA, Villafano GJ, Bornholdt J, Andersson R, Core L, Sandelin A, Jensen TH. The RNA exosome contributes to gene expression regulation during stem cell differentiation. Nucleic Acids Res 2018; 46:11502-11513. [PMID: 30212902 PMCID: PMC6265456 DOI: 10.1093/nar/gky817] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/29/2018] [Accepted: 09/09/2018] [Indexed: 12/27/2022] Open
Abstract
Gene expression programs change during cellular transitions. It is well established that a network of transcription factors and chromatin modifiers regulate RNA levels during embryonic stem cell (ESC) differentiation, but the full impact of post-transcriptional processes remains elusive. While cytoplasmic RNA turnover mechanisms have been implicated in differentiation, the contribution of nuclear RNA decay has not been investigated. Here, we differentiate mouse ESCs, depleted for the ribonucleolytic RNA exosome, into embryoid bodies to determine to which degree RNA abundance in the two states can be attributed to changes in transcription versus RNA decay by the exosome. As a general observation, we find that exosome depletion mainly leads to the stabilization of RNAs from lowly transcribed loci, including several protein-coding genes. Depletion of the nuclear exosome cofactor RBM7 leads to similar effects. In particular, transcripts that are differentially expressed between states tend to be more exosome sensitive in the state where expression is low. We conclude that the RNA exosome contributes to down-regulation of transcripts with disparate expression, often in conjunction with transcriptional down-regulation.
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Affiliation(s)
| | - Evdoxia Karadoulama
- Department of Molecular Biology and Genetics, Aarhus University, Denmark
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Denmark
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Denmark
| | - Yun Chen
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Denmark
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Denmark
| | - Luke A Wojenski
- Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Geno J Villafano
- Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Jette Bornholdt
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Denmark
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Denmark
| | - Robin Andersson
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Denmark
| | - Leighton Core
- Department of Molecular and Cell Biology, Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA
| | - Albin Sandelin
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Denmark
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Denmark
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Nojima T, Tellier M, Foxwell J, Ribeiro de Almeida C, Tan-Wong SM, Dhir S, Dujardin G, Dhir A, Murphy S, Proudfoot NJ. Deregulated Expression of Mammalian lncRNA through Loss of SPT6 Induces R-Loop Formation, Replication Stress, and Cellular Senescence. Mol Cell 2018; 72:970-984.e7. [PMID: 30449723 PMCID: PMC6309921 DOI: 10.1016/j.molcel.2018.10.011] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 07/13/2018] [Accepted: 10/09/2018] [Indexed: 02/06/2023]
Abstract
Extensive tracts of the mammalian genome that lack protein-coding function are still transcribed into long noncoding RNA. While these lncRNAs are generally short lived, length restricted, and non-polyadenylated, how their expression is distinguished from protein-coding genes remains enigmatic. Surprisingly, depletion of the ubiquitous Pol-II-associated transcription elongation factor SPT6 promotes a redistribution of H3K36me3 histone marks from active protein coding to lncRNA genes, which correlates with increased lncRNA transcription. SPT6 knockdown also impairs the recruitment of the Integrator complex to chromatin, which results in a transcriptional termination defect for lncRNA genes. This leads to the formation of extended, polyadenylated lncRNAs that are both chromatin restricted and form increased levels of RNA:DNA hybrid (R-loops) that are associated with DNA damage. Additionally, these deregulated lncRNAs overlap with DNA replication origins leading to localized DNA replication stress and a cellular senescence phenotype. Overall, our results underline the importance of restricting lncRNA expression. SPT6 promotes the selective distribution of H3K36me3 over protein-coding genes SPT6 loss leads to formation of extended lncRNAs that are prone to R-loop formation Deregulated Pol II collides with DNA replisomes on lncRNA genes Collision between Pol II and DNA replisome leads to cellular senescence
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Affiliation(s)
- Takayuki Nojima
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
| | - Michael Tellier
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Jonathan Foxwell
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | | | - Sue Mei Tan-Wong
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Somdutta Dhir
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Gwendal Dujardin
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Ashish Dhir
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
| | - Nick J Proudfoot
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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Qin XG, Zeng JH, Lin P, Mo WJ, Li Q, Feng ZB, Luo DZ, Yang H, Chen G, Zeng JJ. Prognostic value of small nuclear RNAs (snRNAs) for digestive tract pan- adenocarcinomas identified by RNA sequencing data. Pathol Res Pract 2018; 215:414-426. [PMID: 30455130 DOI: 10.1016/j.prp.2018.11.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/24/2018] [Accepted: 11/06/2018] [Indexed: 12/11/2022]
Abstract
Malignant tumors of the digestive tract include esophageal, gastric, and colorectal carcinomas, which all have high global mortality rates. A clinical role for small nuclear RNA (snRNA), a type of small non-coding RNA, has not yet been documented for digestive tract pan-adenocarcinomas. Therefore, the aim of the study was to identify differentially expressed snRNAs and to explore their prognostic implications in pan-adenocarcinomas from the esophagus, stomach, colon, and rectum. The pan-carcinoma RNA-sequencing data of four types of digestive tract cancers with 1, 102 cases obtained from The Cancer Genome Atlas (TCGA) project were analyzed and the differentially expressed snRNAs were evaluated using the edgeR package. The prognostic value of each of the selected snRNAs was determined by univariate and multivariate Cox regression analyses. All the digestive tract pan-adenocarcinomas showed differential expression of three snRNAs: the up-regulated RNU1-106 P and RNU6-850 P and the down-regulated RNU6-529 P. Interestingly, RNU6-101 P appeared to be a risk factor for esophageal adenocarcinoma (ESAD) and RNVU1-4 was potentially a protective factor for stomach adenocarcinoma (STAD) survival. This consistent finding of differential expression of all three snRNAs in all four types of digestive system cancers suggests potential roles for these snRNAs in the tumorigenesis of digestive system cancers. RNU6-101 P could play a pivotal role in the progression of ESAD and RNVU1-4 could perform a protective role in STAD. However, since the current findings were based on RNA-sequencing data mining, more studies are needed for verification.
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Affiliation(s)
- Xin-Gan Qin
- Department of Gastrointestinal Surgery, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Jiang-Hui Zeng
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Peng Lin
- Department of Medical Ultrasonics, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Wei-Jia Mo
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Qing Li
- Department of Medical Ultrasonics, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Zhen-Bo Feng
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Dian-Zhong Luo
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Hong Yang
- Department of Medical Ultrasonics, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Gang Chen
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China
| | - Jing-Jing Zeng
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region 530021, Nanning, PR China.
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75
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Erickson B, Sheridan RM, Cortazar M, Bentley DL. Dynamic turnover of paused Pol II complexes at human promoters. Genes Dev 2018; 32:1215-1225. [PMID: 30150253 PMCID: PMC6120720 DOI: 10.1101/gad.316810.118] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/11/2018] [Indexed: 12/30/2022]
Abstract
Paused RNA polymerase II (Pol II) that piles up near most human promoters is the target of mechanisms that control entry into productive elongation. Whether paused Pol II is a stable or dynamic target remains unresolved. We report that most 5' paused Pol II throughout the genome is turned over within 2 min. This process is revealed under hypertonic conditions that prevent Pol II recruitment to promoters. This turnover requires cell viability but is not prevented by inhibiting transcription elongation, suggesting that it is mediated at the level of termination. When initiation was prevented by triptolide during recovery from high salt, a novel preinitiated state of Pol II lacking the pausing factor Spt5 accumulated at transcription start sites. We propose that Pol II occupancy near 5' ends is governed by a cycle of ongoing assembly of preinitiated complexes that transition to pause sites followed by eviction from the DNA template. This model suggests that mechanisms regulating the transition to productive elongation at pause sites operate on a dynamic population of Pol II that is turning over at rates far higher than previously suspected. We suggest that a plausible alternative to elongation control via escape from a stable pause is by escape from premature termination.
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Affiliation(s)
- Benjamin Erickson
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Ryan M Sheridan
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Michael Cortazar
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - David L Bentley
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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76
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Herzel L, Straube K, Neugebauer KM. Long-read sequencing of nascent RNA reveals coupling among RNA processing events. Genome Res 2018; 28:1008-1019. [PMID: 29903723 PMCID: PMC6028129 DOI: 10.1101/gr.232025.117] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/24/2018] [Indexed: 12/13/2022]
Abstract
Pre-mRNA splicing is accomplished by the spliceosome, a megadalton complex that assembles de novo on each intron. Because spliceosome assembly and catalysis occur cotranscriptionally, we hypothesized that introns are removed in the order of their transcription in genomes dominated by constitutive splicing. Remarkably little is known about splicing order and the regulatory potential of nascent transcript remodeling by splicing, due to the limitations of existing methods that focus on analysis of mature splicing products (mRNAs) rather than substrates and intermediates. Here, we overcome this obstacle through long-read RNA sequencing of nascent, multi-intron transcripts in the fission yeast Schizosaccharomyces pombe. Most multi-intron transcripts were fully spliced, consistent with rapid cotranscriptional splicing. However, an unexpectedly high proportion of transcripts were either fully spliced or fully unspliced, suggesting that splicing of any given intron is dependent on the splicing status of other introns in the transcript. Supporting this, mild inhibition of splicing by a temperature-sensitive mutation in prp2, the homolog of vertebrate U2AF65, increased the frequency of fully unspliced transcripts. Importantly, fully unspliced transcripts displayed transcriptional read-through at the polyA site and were degraded cotranscriptionally by the nuclear exosome. Finally, we show that cellular mRNA levels were reduced in genes with a high number of unspliced nascent transcripts during caffeine treatment, showing regulatory significance of cotranscriptional splicing. Therefore, overall splicing of individual nascent transcripts, 3′ end formation, and mRNA half-life depend on the splicing status of neighboring introns, suggesting crosstalk among spliceosomes and the polyA cleavage machinery during transcription elongation.
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Affiliation(s)
- Lydia Herzel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Korinna Straube
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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77
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78
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Bresson S, Tollervey D. Surveillance-ready transcription: nuclear RNA decay as a default fate. Open Biol 2018; 8:170270. [PMID: 29563193 PMCID: PMC5881035 DOI: 10.1098/rsob.170270] [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: 12/20/2017] [Accepted: 02/23/2018] [Indexed: 12/21/2022] Open
Abstract
Eukaryotic cells synthesize enormous quantities of RNA from diverse classes, most of which are subject to extensive processing. These processes are inherently error-prone, and cells have evolved robust quality control mechanisms to selectively remove aberrant transcripts. These surveillance pathways monitor all aspects of nuclear RNA biogenesis, and in addition remove nonfunctional transcripts arising from spurious transcription and a host of non-protein-coding RNAs (ncRNAs). Surprisingly, this is largely accomplished with only a handful of RNA decay enzymes. It has, therefore, been unclear how these factors efficiently distinguish between functional RNAs and huge numbers of diverse transcripts that must be degraded. Here we describe how bona fide transcripts are specifically protected, particularly by 5' and 3' modifications. Conversely, a plethora of factors associated with the nascent transcripts all act to recruit the RNA quality control, surveillance and degradation machinery. We conclude that initiating RNAPII is 'surveillance ready', with degradation being a default fate for all transcripts that lack specific protective features. We further postulate that this promiscuity is a key feature that allowed the proliferation of vast numbers of ncRNAs in eukaryotes, including humans.
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Affiliation(s)
- Stefan Bresson
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - David Tollervey
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
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