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Gorjifard S, Jores T, Tonnies J, Mueth NA, Bubb K, Wrightsman T, Buckler ES, Fields S, Cuperus JT, Queitsch C. Arabidopsis and maize terminator strength is determined by GC content, polyadenylation motifs and cleavage probability. Nat Commun 2024; 15:5868. [PMID: 38997252 PMCID: PMC11245536 DOI: 10.1038/s41467-024-50174-7] [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: 06/16/2023] [Accepted: 07/03/2024] [Indexed: 07/14/2024] Open
Abstract
The 3' end of a gene, often called a terminator, modulates mRNA stability, localization, translation, and polyadenylation. Here, we adapted Plant STARR-seq, a massively parallel reporter assay, to measure the activity of over 50,000 terminators from the plants Arabidopsis thaliana and Zea mays. We characterize thousands of plant terminators, including many that outperform bacterial terminators commonly used in plants. Terminator activity is species-specific, differing in tobacco leaf and maize protoplast assays. While recapitulating known biology, our results reveal the relative contributions of polyadenylation motifs to terminator strength. We built a computational model to predict terminator strength and used it to conduct in silico evolution that generated optimized synthetic terminators. Additionally, we discover alternative polyadenylation sites across tens of thousands of terminators; however, the strongest terminators tend to have a dominant cleavage site. Our results establish features of plant terminator function and identify strong naturally occurring and synthetic terminators.
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Affiliation(s)
- Sayeh Gorjifard
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Tobias Jores
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Jackson Tonnies
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
- Graduate Program in Biology, University of Washington, Seattle, WA, 98195, USA
| | - Nicholas A Mueth
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Kerry Bubb
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Travis Wrightsman
- Section of Plant Breeding and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Edward S Buckler
- Section of Plant Breeding and Genetics, Cornell University, Ithaca, NY, 14853, USA
- Agricultural Research Service, United States Department of Agriculture, Ithaca, NY, 14853, USA
- Institute for Genomic Diversity, Cornell University, Ithaca, NY, 14853, USA
| | - Stanley Fields
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
- Department of Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Josh T Cuperus
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA.
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2
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Izquierdo-Pujol J, Puertas MC, Martinez-Picado J, Morón-López S. Targeting Viral Transcription for HIV Cure Strategies. Microorganisms 2024; 12:752. [PMID: 38674696 PMCID: PMC11052381 DOI: 10.3390/microorganisms12040752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 04/05/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
Combination antiretroviral therapy (ART) suppresses viral replication to undetectable levels, reduces mortality and morbidity, and improves the quality of life of people living with HIV (PWH). However, ART cannot cure HIV infection because it is unable to eliminate latently infected cells. HIV latency may be regulated by different HIV transcription mechanisms, such as blocks to initiation, elongation, and post-transcriptional processes. Several latency-reversing (LRA) and -promoting agents (LPA) have been investigated in clinical trials aiming to eliminate or reduce the HIV reservoir. However, none of these trials has shown a conclusive impact on the HIV reservoir. Here, we review the cellular and viral factors that regulate HIV-1 transcription, the potential pharmacological targets and genetic and epigenetic editing techniques that have been or might be evaluated to disrupt HIV-1 latency, the role of miRNA in post-transcriptional regulation of HIV-1, and the differences between the mechanisms regulating HIV-1 and HIV-2 expression.
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Affiliation(s)
- Jon Izquierdo-Pujol
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
| | - Maria C. Puertas
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
- CIBERINFEC, 28029 Madrid, Spain
| | - Javier Martinez-Picado
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
- CIBERINFEC, 28029 Madrid, Spain
- Department of Infectious Diseases and Immunity, School of Medicine, University of Vic-Central University of Catalonia (UVic-UCC), 08500 Vic, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
| | - Sara Morón-López
- IrsiCaixa, 08916 Badalona, Spain; (J.I.-P.); (M.C.P.); (J.M.-P.)
- Germans Trias i Pujol Research Institute (IGTP), 08916 Badalona, Spain
- CIBERINFEC, 28029 Madrid, Spain
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3
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Chou SP, Alexander AK, Rice EJ, Choate LA, Danko CG. Genetic dissection of the RNA polymerase II transcription cycle. eLife 2022; 11:78458. [PMID: 35775732 PMCID: PMC9286732 DOI: 10.7554/elife.78458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/30/2022] [Indexed: 11/20/2022] Open
Abstract
How DNA sequence affects the dynamics and position of RNA Polymerase II (Pol II) during transcription remains poorly understood. Here, we used naturally occurring genetic variation in F1 hybrid mice to explore how DNA sequence differences affect the genome-wide distribution of Pol II. We measured the position and orientation of Pol II in eight organs collected from heterozygous F1 hybrid mice using ChRO-seq. Our data revealed a strong genetic basis for the precise coordinates of transcription initiation and promoter proximal pause, allowing us to redefine molecular models of core transcriptional processes. Our results implicate DNA sequence, including both known and novel DNA sequence motifs, as key determinants of the position of Pol II initiation and pause. We report evidence that initiation site selection follows a stochastic process similar to Brownian motion along the DNA template. We found widespread differences in the position of transcription termination, which impact the primary structure and stability of mature mRNA. Finally, we report evidence that allelic changes in transcription often affect mRNA and ncRNA expression across broad genomic domains. Collectively, we reveal how DNA sequences shape core transcriptional processes at single nucleotide resolution in mammals.
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Affiliation(s)
- Shao-Pei Chou
- Baker Institute for Animal Health, Cornell University, Ithaca, United States
| | - Adriana K Alexander
- Baker Institute for Animal Health, Cornell University, Ithaca, United States
| | - Edward J Rice
- Baker Institute for Animal Health, Cornell University, Ithaca, United States
| | - Lauren A Choate
- Baker Institute for Animal Health, Cornell University, Ithaca, United States
| | - Charles G Danko
- Baker Institute for Animal Health, Cornell University, Ithaca, United States
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4
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CSB-independent, XPC-dependent transcription-coupled repair in Drosophila. Proc Natl Acad Sci U S A 2022; 119:2123163119. [PMID: 35217627 PMCID: PMC8892495 DOI: 10.1073/pnas.2123163119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2022] [Indexed: 02/08/2023] Open
Abstract
Drosophila melanogaster has been extensively used as a model system to study ionizing radiation and chemical-induced mutagenesis, double-strand break repair, and recombination. However, there are only limited studies on nucleotide excision repair in this important model organism. An early study reported that Drosophila lacks the transcription-coupled repair (TCR) form of nucleotide excision repair. This conclusion was seemingly supported by the Drosophila genome sequencing project, which revealed that Drosophila lacks a homolog to CSB, which is known to be required for TCR in mammals and yeasts. However, by using excision repair sequencing (XR-seq) genome-wide repair mapping technology, we recently found that the Drosophila S2 cell line performs TCR comparable to human cells. Here, we have extended this work to Drosophila at all its developmental stages. We find TCR takes place throughout the life cycle of the organism. Moreover, we find that in contrast to humans and other multicellular organisms previously studied, the XPC repair factor is required for both global and transcription-coupled repair in Drosophila.
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5
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Mo W, Liu B, Zhang H, Jin X, Lu D, Yu Y, Liu Y, Jia J, Long Y, Deng X, Cao X, Guo H, Zhai J. Landscape of transcription termination in Arabidopsis revealed by single-molecule nascent RNA sequencing. Genome Biol 2021; 22:322. [PMID: 34823554 PMCID: PMC8613925 DOI: 10.1186/s13059-021-02543-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 11/01/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The dynamic process of transcription termination produces transient RNA intermediates that are difficult to distinguish from each other via short-read sequencing methods. RESULTS Here, we use single-molecule nascent RNA sequencing to characterize the various forms of transient RNAs during termination at genome-wide scale in wildtype Arabidopsis and in atxrn3, fpa, and met1 mutants. Our data reveal a wide range of termination windows among genes, ranging from ~ 50 nt to over 1000 nt. We also observe efficient termination before downstream tRNA genes, suggesting that chromatin structure around the promoter region of tRNA genes may block pol II elongation. 5' Cleaved readthrough transcription in atxrn3 with delayed termination can run into downstream genes to produce normally spliced and polyadenylated mRNAs in the absence of their own transcription initiation. Consistent with previous reports, we also observe long chimeric transcripts with cryptic splicing in fpa mutant; but loss of CG DNA methylation has no obvious impact on termination in the met1 mutant. CONCLUSIONS Our method is applicable to establish a comprehensive termination landscape in a broad range of species.
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Affiliation(s)
- Weipeng Mo
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Bo Liu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Hong Zhang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xianhao Jin
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Dongdong Lu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yiming Yu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yuelin Liu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jinbu Jia
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yanping Long
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xian Deng
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaofeng Cao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hongwei Guo
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jixian Zhai
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
- Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen, 518055, China.
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Southern University of Science and Technology, Shenzhen, 518055, China.
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6
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Soles LV, Shi Y. Crosstalk Between mRNA 3'-End Processing and Epigenetics. Front Genet 2021; 12:637705. [PMID: 33613650 PMCID: PMC7890070 DOI: 10.3389/fgene.2021.637705] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/06/2021] [Indexed: 12/02/2022] Open
Abstract
The majority of eukaryotic genes produce multiple mRNA isoforms by using alternative poly(A) sites in a process called alternative polyadenylation (APA). APA is a dynamic process that is highly regulated in development and in response to extrinsic or intrinsic stimuli. Mis-regulation of APA has been linked to a wide variety of diseases, including cancer, neurological and immunological disorders. Since the first example of APA was described 40 years ago, the regulatory mechanisms of APA have been actively investigated. Conventionally, research in this area has focused primarily on the roles of regulatory cis-elements and trans-acting RNA-binding proteins. Recent studies, however, have revealed important functions for epigenetic mechanisms, including DNA and histone modifications and higher-order chromatin structures, in APA regulation. Here we will discuss these recent findings and their implications for our understanding of the crosstalk between epigenetics and mRNA 3'-end processing.
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Affiliation(s)
- Lindsey V Soles
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, United States
| | - Yongsheng Shi
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, United States
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7
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Integrator is a genome-wide attenuator of non-productive transcription. Mol Cell 2020; 81:514-529.e6. [PMID: 33385327 DOI: 10.1016/j.molcel.2020.12.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 10/11/2020] [Accepted: 11/20/2020] [Indexed: 12/28/2022]
Abstract
Termination of RNA polymerase II (RNAPII) transcription in metazoans relies largely on the cleavage and polyadenylation (CPA) and integrator (INT) complexes originally found to act at the ends of protein-coding and small nuclear RNA (snRNA) genes, respectively. Here, we monitor CPA- and INT-dependent termination activities genome-wide, including at thousands of previously unannotated transcription units (TUs), producing unstable RNA. We verify the global activity of CPA occurring at pA sites indiscriminately of their positioning relative to the TU promoter. We also identify a global activity of INT, which is largely sequence-independent and restricted to a ~3-kb promoter-proximal region. Our analyses suggest two functions of genome-wide INT activity: it dampens transcriptional output from weak promoters, and it provides quality control of RNAPII complexes that are unfavorably configured for transcriptional elongation. We suggest that the function of INT in stable snRNA production is an exception from its general cellular role, the attenuation of non-productive transcription.
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8
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Lamana A, Villares R, Seoane IV, Andrés N, Lucas P, Emery P, Vital EM, Triguero-Martínez A, Marquez A, Ortiz AM, Maxime R, Martínez C, Martín J, Gomariz RP, Ponchel F, González-Álvaro I, Mellado M. Identification of a Human SOCS1 Polymorphism That Predicts Rheumatoid Arthritis Severity. Front Immunol 2020; 11:1336. [PMID: 32670294 PMCID: PMC7332777 DOI: 10.3389/fimmu.2020.01336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 05/26/2020] [Indexed: 12/17/2022] Open
Abstract
Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an autoimmune response in the joints and an exacerbation of cytokine responses. A minority of patients with RA experience spontaneous remission, but most will show moderate/high disease activity, with aggressive joint damage and multiple systemic manifestations. There is thus is a great need to identify prognostic biomarkers for disease risk to improve diagnosis and prognosis, and to inform on the most appropriate therapy. Here we focused on suppressor of cytokine signaling 1 (SOCS1), a physiological negative regulator of cytokines that modulates cell activation. Using four independent cohorts of patients with arthritis, we characterized the correlation between SOCS1 mRNA levels and clinical outcome. We found a significant inverse correlation between SOCS1 mRNA expression and disease activity throughout the follow-up of patients with RA. Lower baseline SOCS1 levels were associated with poorer disease control in response to methotrexate and other conventional synthetic disease-modifying anti-rheumatic drugs in early arthritis, and to rituximab in established (active) RA. Moreover, we identified several single nucleotide polymorphisms in the SOCS1 gene that correlated with SOCS1 mRNA expression, and that might identify those patients with early arthritis that fulfill RA classification criteria. One of them, rs4780355, is in linkage disequilibrium with a microsatellite (TTTTC)3−5, mapped 0.9 kb downstream of the SNP, and correlated with reduced SOCS1 expression in vitro. Overall, our data support the association between SOCS1 expression and disease progression, disease severity and response to treatment in RA. These observations underlie the relevance of SOCS1 mRNA levels for stratifying patients prognostically and guiding therapeutic decisions.
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Affiliation(s)
- Amalia Lamana
- Rheumatology Service, Instituto de Investigación Sanitaria La Princesa, Hospital Universitario de la Princesa, Madrid, Spain
| | - Ricardo Villares
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - Iria V Seoane
- Department of Cellular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Nuria Andrés
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - Pilar Lucas
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | - Paul Emery
- Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), The University of Leeds, Leeds, United Kingdom
| | - Edward M Vital
- Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), The University of Leeds, Leeds, United Kingdom
| | - Ana Triguero-Martínez
- Rheumatology Service, Instituto de Investigación Sanitaria La Princesa, Hospital Universitario de la Princesa, Madrid, Spain
| | - Ana Marquez
- Institute of Parasitology and Biomedicine López-Neyra, CSIC, Granada, Spain
| | - Ana M Ortiz
- Rheumatology Service, Instituto de Investigación Sanitaria La Princesa, Hospital Universitario de la Princesa, Madrid, Spain
| | - Robin Maxime
- Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), The University of Leeds, Leeds, United Kingdom
| | - Carmen Martínez
- Department of Cellular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Javier Martín
- Institute of Parasitology and Biomedicine López-Neyra, CSIC, Granada, Spain
| | - Rosa P Gomariz
- Department of Cellular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Frederique Ponchel
- Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), The University of Leeds, Leeds, United Kingdom
| | - Isidoro González-Álvaro
- Rheumatology Service, Instituto de Investigación Sanitaria La Princesa, Hospital Universitario de la Princesa, Madrid, Spain
| | - Mario Mellado
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
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9
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Phung DK, Etienne C, Batista M, Langendijk-Genevaux P, Moalic Y, Laurent S, Liuu S, Morales V, Jebbar M, Fichant G, Bouvier M, Flament D, Clouet-d’Orval B. RNA processing machineries in Archaea: the 5'-3' exoribonuclease aRNase J of the β-CASP family is engaged specifically with the helicase ASH-Ski2 and the 3'-5' exoribonucleolytic RNA exosome machinery. Nucleic Acids Res 2020; 48:3832-3847. [PMID: 32030412 PMCID: PMC7144898 DOI: 10.1093/nar/gkaa052] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/14/2020] [Accepted: 01/23/2020] [Indexed: 01/22/2023] Open
Abstract
A network of RNA helicases, endoribonucleases and exoribonucleases regulates the quantity and quality of cellular RNAs. To date, mechanistic studies focussed on bacterial and eukaryal systems due to the challenge of identifying the main drivers of RNA decay and processing in Archaea. Here, our data support that aRNase J, a 5'-3' exoribonuclease of the β-CASP family conserved in Euryarchaeota, engages specifically with a Ski2-like helicase and the RNA exosome to potentially exert control over RNA surveillance, at the vicinity of the ribosome. Proteomic landscapes and direct protein-protein interaction analyses, strengthened by comprehensive phylogenomic studies demonstrated that aRNase J interplay with ASH-Ski2 and a cap exosome subunit. Finally, Thermococcus barophilus whole-cell extract fractionation experiments provide evidences that an aRNase J/ASH-Ski2 complex might exist in vivo and hint at an association of aRNase J with the ribosome that is emphasised in absence of ASH-Ski2. Whilst aRNase J homologues are found among bacteria, the RNA exosome and the Ski2-like RNA helicase have eukaryotic homologues, underlining the mosaic aspect of archaeal RNA machines. Altogether, these results suggest a fundamental role of β-CASP RNase/helicase complex in archaeal RNA metabolism.
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Affiliation(s)
- Duy Khanh Phung
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
| | - Clarisse Etienne
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
| | - Manon Batista
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
| | - Petra Langendijk-Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
| | - Yann Moalic
- Ifremer, Univ Brest, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes, F-29280 Plouzané, France
| | - Sébastien Laurent
- Ifremer, Univ Brest, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes, F-29280 Plouzané, France
| | - Sophie Liuu
- Micalis Institute, PAPPSO, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Violette Morales
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
| | - Mohamed Jebbar
- Ifremer, Univ Brest, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes, F-29280 Plouzané, France
| | - Gwennaele Fichant
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
| | - Marie Bouvier
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
| | - Didier Flament
- Ifremer, Univ Brest, CNRS, Laboratoire de Microbiologie des Environnements Extrêmes, F-29280 Plouzané, France
| | - Béatrice Clouet-d’Orval
- Laboratoire de Microbiologie et de Génétique Moléculaires, UMR5100, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Paul Sabatier, F-31062 Toulouse, France
- To whom correspondence should be addressed. Tel: +33 561 335 875; Fax: +33 561 335 886;
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10
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Lee JS, Mendell JT. Antisense-Mediated Transcript Knockdown Triggers Premature Transcription Termination. Mol Cell 2020; 77:1044-1054.e3. [PMID: 31924448 DOI: 10.1016/j.molcel.2019.12.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/11/2019] [Accepted: 12/12/2019] [Indexed: 12/15/2022]
Abstract
Antisense oligonucleotides (ASOs) that trigger RNase-H-mediated cleavage are commonly used to knock down transcripts for experimental or therapeutic purposes. In particular, ASOs are frequently used to functionally interrogate long noncoding RNAs (lncRNAs) and discriminate lncRNA loci that produce functional RNAs from those whose activity is attributable to the act of transcription. Transcription termination is triggered by cleavage of nascent transcripts, generally during polyadenylation, resulting in degradation of the residual RNA polymerase II (Pol II)-associated RNA by XRN2 and dissociation of elongating Pol II. Here, we show that ASOs act upon nascent transcripts and, consequently, induce premature transcription termination downstream of the cleavage site in an XRN2-dependent manner. Targeting the transcript 3' end with ASOs, however, allows transcript knockdown while preserving Pol II association with the gene body. These results demonstrate that the effects of ASOs on transcription must be considered for appropriate experimental and therapeutic use of these reagents.
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Affiliation(s)
- Jong-Sun Lee
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - Joshua T Mendell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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11
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Campbell JB, Edwards MJ, Ozersky SA, Duina AA. Evidence that dissociation of Spt16 from transcribed genes is partially dependent on RNA Polymerase II termination. Transcription 2019; 10:195-206. [PMID: 31809228 PMCID: PMC6948958 DOI: 10.1080/21541264.2019.1685837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
FACT (FAcilitates Chromatin Transactions) is a highly conserved histone chaperone complex in eukaryotic cells that can interact and manipulate nucleosomes in order to promote a variety of DNA-based processes and to maintain the integrity of chromatin throughout the genome. Whereas key features of the physical interactions that occur between FACT and nucleosomes in vitro have been elucidated in recent years, less is known regarding FACT functional dynamics in vivo. Using the Saccharomyces cerevisiae system, we now provide evidence that at least at some genes dissociation of the FACT subunit Spt16 from their 3′ ends is partially dependent on RNA Polymerase II (Pol II) termination. Combined with other studies, our results are consistent with a two-phase mechanism for FACT dissociation from genes, one that occurs upstream from Pol II dissociation and is Pol II termination-independent and the other that occurs further downstream and is dependent on Pol II termination.
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Affiliation(s)
| | | | | | - Andrea A Duina
- Biology Department, Hendrix College, Conway, Arkansas, USA
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12
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Distinct Functions of the Cap-Binding Complex in Stimulation of Nuclear mRNA Export. Mol Cell Biol 2019; 39:MCB.00540-18. [PMID: 30745412 DOI: 10.1128/mcb.00540-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/23/2019] [Indexed: 11/20/2022] Open
Abstract
Cap-binding complex (CBC) associates cotranscriptionally with the cap structure at the 5' end of nascent mRNA to protect it from exonucleolytic degradation. Here, we show that CBC promotes the targeting of an mRNA export adaptor, Yra1 (forming transcription export [TREX] complex with THO and Sub2), to the active genes and enhances mRNA export in Saccharomyces cerevisiae Likewise, recruitment of Npl3 (an hnRNP involved in mRNA export via formation of export-competent ribonuclear protein complex [RNP]) to the active genes is facilitated by CBC. Thus, CBC enhances targeting of the export factors and promotes mRNA export. Such function of CBC is not mediated via THO and Sub2 of TREX, cleavage and polyadenylation factors, or Sus1 (that regulates mRNA export via transcription export 2 [TREX-2]). However, CBC promotes splicing of SUS1 mRNA and, consequently, Sus1 protein level and mRNA export via TREX-2. Collectively, our results support the hypothesis that CBC promotes recruitment of Yra1 and Npl3 to the active genes, independently of THO, Sub2, or cleavage and polyadenylation factors, and enhances mRNA export via TREX and RNP, respectively, in addition to its role in facilitating SUS1 mRNA splicing to increase mRNA export through TREX-2, revealing distinct stimulatory functions of CBC in mRNA export.
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13
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Kindgren P, Ard R, Ivanov M, Marquardt S. Transcriptional read-through of the long non-coding RNA SVALKA governs plant cold acclimation. Nat Commun 2018; 9:4561. [PMID: 30385760 PMCID: PMC6212407 DOI: 10.1038/s41467-018-07010-6] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 10/10/2018] [Indexed: 02/08/2023] Open
Abstract
Most DNA in the genomes of higher organisms does not encode proteins, yet much is transcribed by RNA polymerase II (RNAPII) into long non-coding RNAs (lncRNAs). The biological significance of most lncRNAs is largely unclear. Here, we identify a lncRNA (SVALKA) in a cold-sensitive region of the Arabidopsis genome. Mutations in SVALKA affect CBF1 expression and freezing tolerance. RNAPII read-through transcription of SVALKA results in a cryptic lncRNA overlapping CBF1 on the antisense strand, termed asCBF1. Our molecular dissection reveals that CBF1 is suppressed by RNAPII collision stemming from the SVALKA-asCBF1 lncRNA cascade. The SVALKA-asCBF1 cascade provides a mechanism to tightly control CBF1 expression and timing that could be exploited to maximize freezing tolerance with mitigated fitness costs. Our results provide a compelling example of local gene regulation by lncRNA transcription having a profound impact on the ability of plants to appropriately acclimate to challenging environmental conditions. The function of most lncRNA is unknown. Here, the authors show that transcriptional read-through at the Arabidopsis SVALKA locus produces a cryptic lncRNA that overlaps with the neighboring cold-responsive CBF1 gene and limits CBF1 expression via an RNA polymerase II collision-based mechanism.
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Affiliation(s)
- Peter Kindgren
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Bulowsvej 34, Frederiksberg, 1871, Denmark
| | - Ryan Ard
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Bulowsvej 34, Frederiksberg, 1871, Denmark
| | - Maxim Ivanov
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Bulowsvej 34, Frederiksberg, 1871, Denmark
| | - Sebastian Marquardt
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Bulowsvej 34, Frederiksberg, 1871, Denmark.
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14
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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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15
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Richard P, Vethantham V, Manley JL. Roles of Sumoylation in mRNA Processing and Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 963:15-33. [PMID: 28197904 DOI: 10.1007/978-3-319-50044-7_2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
SUMO has gained prominence as a regulator in a number of cellular processes. The roles of sumoylation in RNA metabolism, however, while considerable, remain less well understood. In this chapter we have assembled data from proteomic analyses, localization studies and key functional studies to extend SUMO's role to the area of mRNA processing and metabolism. Proteomic analyses have identified multiple putative sumoylation targets in complexes functioning in almost all aspects of mRNA metabolism, including capping, splicing and polyadenylation of mRNA precursors. Possible regulatory roles for SUMO have emerged in pre-mRNA 3' processing, where SUMO influences the functions of polyadenylation factors and activity of the entire complex. SUMO is also involved in regulating RNA editing and RNA binding by hnRNP proteins, and recent reports have suggested the involvement of the SUMO pathway in mRNA export. Together, these reports suggest that SUMO is involved in regulation of many aspects of mRNA metabolism and hold the promise for exciting future studies.
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Affiliation(s)
- Patricia Richard
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | | | - James L Manley
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA.
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16
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Unusual Processing Generates SPA LncRNAs that Sequester Multiple RNA Binding Proteins. Mol Cell 2016; 64:534-548. [DOI: 10.1016/j.molcel.2016.10.007] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 07/22/2016] [Accepted: 10/04/2016] [Indexed: 12/13/2022]
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17
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Abstract
Termination of RNA polymerase II (RNAPII) transcription is a fundamental step of gene expression that involves the release of the nascent transcript and dissociation of RNAPII from the DNA template. As transcription termination is intimately linked to RNA 3' end processing, termination pathways have a key decisive influence on the fate of the transcribed RNA. Quite remarkably, when reaching the 3' end of genes, a substantial fraction of RNAPII fail to terminate transcription, requiring the contribution of alternative or "fail-safe" mechanisms of termination to release the polymerase. This point of view covers redundant mechanisms of transcription termination and how they relate to conventional termination models. In particular, we expand on recent findings that propose a reverse torpedo model of termination, in which the 3'5' exonucleolytic activity of the RNA exosome targets transcription events associated with paused and backtracked RNAPII.
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Affiliation(s)
- Jean-François Lemay
- a Department of Biochemistry ; Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Pavillon de Recherche Appliquée sur le Cancer (PRAC) ; Sherbrooke, Quebec
| | - François Bachand
- a Department of Biochemistry ; Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Pavillon de Recherche Appliquée sur le Cancer (PRAC) ; Sherbrooke, Quebec
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18
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Ogorodnikov A, Kargapolova Y, Danckwardt S. Processing and transcriptome expansion at the mRNA 3' end in health and disease: finding the right end. Pflugers Arch 2016; 468:993-1012. [PMID: 27220521 PMCID: PMC4893057 DOI: 10.1007/s00424-016-1828-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 04/19/2016] [Indexed: 01/09/2023]
Abstract
The human transcriptome is highly dynamic, with each cell type, tissue, and organ system expressing an ensemble of transcript isoforms that give rise to considerable diversity. Apart from alternative splicing affecting the "body" of the transcripts, extensive transcriptome diversification occurs at the 3' end. Transcripts differing at the 3' end can have profound physiological effects by encoding proteins with distinct functions or regulatory properties or by affecting the mRNA fate via the inclusion or exclusion of regulatory elements (such as miRNA or protein binding sites). Importantly, the dynamic regulation at the 3' end is associated with various (patho)physiological processes, including the immune regulation but also tumorigenesis. Here, we recapitulate the mechanisms of constitutive mRNA 3' end processing and review the current understanding of the dynamically regulated diversity at the transcriptome 3' end. We illustrate the medical importance by presenting examples that are associated with perturbations of this process and indicate resulting implications for molecular diagnostics as well as potentially arising novel therapeutic strategies.
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Affiliation(s)
- Anton Ogorodnikov
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Langenbeckstr 1, 55131, Mainz, Germany
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Langenbeckstr 1, 55131, Mainz, Germany
| | - Yulia Kargapolova
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Langenbeckstr 1, 55131, Mainz, Germany
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Langenbeckstr 1, 55131, Mainz, Germany
| | - Sven Danckwardt
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Langenbeckstr 1, 55131, Mainz, Germany.
- Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Langenbeckstr 1, 55131, Mainz, Germany.
- German Center for Cardiovascular Research (DZHK), Langenbeckstr 1, 55131, Mainz, Germany.
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19
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Lee JH, Kang BH, Jang H, Kim TW, Choi J, Kwak S, Han J, Cho EJ, Youn HD. AKT phosphorylates H3-threonine 45 to facilitate termination of gene transcription in response to DNA damage. Nucleic Acids Res 2015; 43:4505-16. [PMID: 25813038 PMCID: PMC4482061 DOI: 10.1093/nar/gkv176] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 02/20/2015] [Indexed: 11/13/2022] Open
Abstract
Post-translational modifications of core histones affect various cellular processes, primarily through transcription. However, their relationship with the termination of transcription has remained largely unknown. In this study, we show that DNA damage-activated AKT phosphorylates threonine 45 of core histone H3 (H3-T45). By genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) analysis, H3-T45 phosphorylation was distributed throughout DNA damage-responsive gene loci, particularly immediately after the transcription termination site. H3-T45 phosphorylation pattern showed close-resemblance to that of RNA polymerase II C-terminal domain (CTD) serine 2 phosphorylation, which establishes the transcription termination signal. AKT1 was more effective than AKT2 in phosphorylating H3-T45. Blocking H3-T45 phosphorylation by inhibiting AKT or through amino acid substitution limited RNA decay downstream of mRNA cleavage sites and decreased RNA polymerase II release from chromatin. Our findings suggest that AKT-mediated phosphorylation of H3-T45 regulates the processing of the 3' end of DNA damage-activated genes to facilitate transcriptional termination.
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Affiliation(s)
- Jong-Hyuk Lee
- National Creative Research Center for Epigenome Reprogramming Network, Department of Biomedical Sciences, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Byung-Hee Kang
- National Creative Research Center for Epigenome Reprogramming Network, Department of Biomedical Sciences, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Hyonchol Jang
- Division of Cancer Biology, Research Institute, National Cancer Center, Goyang 410-769, Republic of Korea
| | - Tae Wan Kim
- National Creative Research Center for Epigenome Reprogramming Network, Department of Biomedical Sciences, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Jinmi Choi
- National Creative Research Center for Epigenome Reprogramming Network, Department of Biomedical Sciences, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Sojung Kwak
- National Creative Research Center for Epigenome Reprogramming Network, Department of Biomedical Sciences, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Jungwon Han
- National Creative Research Center for Epigenome Reprogramming Network, Department of Biomedical Sciences, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea
| | - Eun-Jung Cho
- College of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Hong-Duk Youn
- National Creative Research Center for Epigenome Reprogramming Network, Department of Biomedical Sciences, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence and Technology, Seoul National University, Seoul 110-799, Republic of Korea
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20
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Yamamoto J, Hagiwara Y, Chiba K, Isobe T, Narita T, Handa H, Yamaguchi Y. DSIF and NELF interact with Integrator to specify the correct post-transcriptional fate of snRNA genes. Nat Commun 2014; 5:4263. [PMID: 24968874 DOI: 10.1038/ncomms5263] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 06/01/2014] [Indexed: 01/26/2023] Open
Abstract
The elongation factors DSIF and NELF are responsible for promoter-proximal RNA polymerase II (Pol II) pausing. NELF is also involved in 3' processing of replication-dependent histone genes, which produce non-polyadenylated mRNAs. Here we show that DSIF and NELF contribute to the synthesis of small nuclear RNAs (snRNAs) through their association with Integrator, the large multisubunit complex responsible for 3' processing of pre-snRNAs. In HeLa cells, Pol II, Integrator, DSIF and NELF accumulate at the 3' end of the U1 snRNA gene. Knockdown of NELF results in misprocessing of U1, U2, U4 and U5 snRNAs, while DSIF is required for proper transcription of these genes. Knocking down NELF also disrupts transcription termination and induces the production of polyadenylated U1 transcripts caused by an enhanced recruitment of cleavage stimulation factor. Our results indicate that NELF plays a key role in determining the post-transcriptional fate of Pol II-transcribed genes.
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Affiliation(s)
- Junichi Yamamoto
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Yuri Hagiwara
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Kunitoshi Chiba
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Tomoyasu Isobe
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Takashi Narita
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Hiroshi Handa
- Department of Nanoparticle Translational Research, Tokyo Medical University, Tokyo 160-8402, Japan
| | - Yuki Yamaguchi
- 1] Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan [2] PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
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21
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Natarajan M, Schiralli Lester GM, Lee C, Missra A, Wasserman GA, Steffen M, Gilmour DS, Henderson AJ. Negative elongation factor (NELF) coordinates RNA polymerase II pausing, premature termination, and chromatin remodeling to regulate HIV transcription. J Biol Chem 2013; 288:25995-26003. [PMID: 23884411 DOI: 10.1074/jbc.m113.496489] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A barrier to eradicating HIV infection is targeting and eliminating latently infected cells. Events that contribute to HIV transcriptional latency include repressive chromatin structure, transcriptional interference, the inability of Tat to recruit positive transcription factor b, and poor processivity of RNA polymerase II (RNAP II). In this study, we investigated mechanisms by which negative elongation factor (NELF) establishes and maintains HIV latency. Negative elongation factor (NELF) induces RNAP II promoter proximal pausing and limits provirus expression in HIV-infected primary CD4(+) T cells. Decreasing NELF expression overcomes RNAP II pausing to enhance HIV transcription elongation in infected primary T cells, demonstrating the importance of pausing in repressing HIV transcription. We also show that RNAP II pausing is coupled to premature transcription termination and chromatin remodeling. NELF interacts with Pcf11, a transcription termination factor, and diminishing Pcf11 in primary CD4(+) T cells induces HIV transcription elongation. In addition, we identify NCoR1-GPS2-HDAC3 as a NELF-interacting corepressor complex that is associated with repressed HIV long terminal repeats. We propose a model in which NELF recruits Pcf11 and NCoR1-GPS2-HDAC3 to paused RNAP II, reinforcing repression of HIV transcription and establishing a critical checkpoint for HIV transcription and latency.
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Affiliation(s)
- Malini Natarajan
- From the Immunology and Infectious Diseases, Integrated Biosciences Graduate Program, Penn State University, University Park, Pennsylvania 16802,; the Departments of Medicine and Infectious Diseases
| | | | - Chanhyo Lee
- the Departments of Medicine and Infectious Diseases
| | - Anamika Missra
- the Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania 16802
| | | | - Martin Steffen
- Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts 02118 and
| | - David S Gilmour
- the Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania 16802
| | - Andrew J Henderson
- the Departments of Medicine and Infectious Diseases,; Microbiology, and.
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22
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Jeronimo C, Bataille AR, Robert F. The Writers, Readers, and Functions of the RNA Polymerase II C-Terminal Domain Code. Chem Rev 2013; 113:8491-522. [DOI: 10.1021/cr4001397] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Célia Jeronimo
- Institut de recherches cliniques de Montréal, Montréal, Québec,
Canada H2W 1R7
| | - Alain R. Bataille
- Institut de recherches cliniques de Montréal, Montréal, Québec,
Canada H2W 1R7
| | - François Robert
- Institut de recherches cliniques de Montréal, Montréal, Québec,
Canada H2W 1R7
- Département
de Médecine,
Faculté de Médecine, Université de Montréal, Montréal, Québec,
Canada H3T 1J4
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23
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Nagarajan VK, Jones CI, Newbury SF, Green PJ. XRN 5'→3' exoribonucleases: structure, mechanisms and functions. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1829:590-603. [PMID: 23517755 PMCID: PMC3742305 DOI: 10.1016/j.bbagrm.2013.03.005] [Citation(s) in RCA: 247] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 03/08/2013] [Accepted: 03/11/2013] [Indexed: 01/11/2023]
Abstract
The XRN family of 5'→3' exoribonucleases is critical for ensuring the fidelity of cellular RNA turnover in eukaryotes. Highly conserved across species, the family is typically represented by one cytoplasmic enzyme (XRN1/PACMAN or XRN4) and one or more nuclear enzymes (XRN2/RAT1 and XRN3). Cytoplasmic and/or nuclear XRNs have proven to be essential in all organisms tested, and deficiencies can have severe developmental phenotypes, demonstrating that XRNs are indispensable in fungi, plants and animals. XRNs degrade diverse RNA substrates during general RNA decay and function in specialized processes integral to RNA metabolism, such as nonsense-mediated decay (NMD), gene silencing, rRNA maturation, and transcription termination. Here, we review current knowledge of XRNs, highlighting recent work of high impact and future potential. One example is the breakthrough in our understanding of how XRN1 processively degrades 5' monophosphorylated RNA, revealed by its crystal structure and mutational analysis. The expanding knowledge of XRN substrates and interacting partners is outlined and the functions of XRNs are interpreted at the organismal level using available mutant phenotypes. Finally, three case studies are discussed in more detail to underscore a few of the most exciting areas of research on XRN function: XRN4 involvement in small RNA-associated processes in plants, the roles of XRN1/PACMAN in Drosophila development, and the function of human XRN2 in nuclear transcriptional quality control. This article is part of a Special Issue entitled: RNA Decay mechanisms.
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Affiliation(s)
- Vinay K. Nagarajan
- Delaware Biotechnology Institute, Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19711, USA
| | - Christopher I. Jones
- Medical Research Building, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton BN1 9PS, UK
| | - Sarah F. Newbury
- Medical Research Building, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton BN1 9PS, UK
| | - Pamela J. Green
- Delaware Biotechnology Institute, Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19711, USA
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24
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Dominski Z, Carpousis AJ, Clouet-d'Orval B. Emergence of the β-CASP ribonucleases: highly conserved and ubiquitous metallo-enzymes involved in messenger RNA maturation and degradation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:532-51. [PMID: 23403287 DOI: 10.1016/j.bbagrm.2013.01.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 01/18/2013] [Accepted: 01/22/2013] [Indexed: 01/05/2023]
Abstract
The β-CASP ribonucleases, which are found in the three domains of life, have in common a core of 460 residues containing seven conserved sequence motifs involved in the tight binding of two catalytic zinc ions. A hallmark of these enzymes is their ability to catalyze both endo- and exo-ribonucleolytic degradation. Exo-ribonucleolytic degradation proceeds in the 5' to 3' direction and is sensitive to the phosphorylation state of the 5' end of a transcript. Recent phylogenomic analyses have shown that the β-CASP ribonucleases can be partitioned into two major subdivisions that correspond to orthologs of eukaryal CPSF73 and bacterial RNase J. We discuss the known functions of the CPSF73 and RNase J orthologs, their association into complexes, and their structure as it relates to mechanism of action. Eukaryal CPSF73 is part of a large multiprotein complex that is involved in the maturation of the 3' end of RNA Polymerase II transcripts and the polyadenylation of messenger RNA. RNase J1 and J2 are paralogs in Bacillus subtilis that are involved in the degradation of messenger RNA and the maturation of non-coding RNA. RNase J1 and J2 co-purify as a heteromeric complex and there is recent evidence that they interact with other enzymes to form a bacterial RNA degradosome. Finally, we speculate on the evolutionary origin of β-CASP ribonucleases and on their functions in Archaea. Orthologs of CPSF73 with endo- and exo-ribonuclease activity are strictly conserved throughout the archaea suggesting a role for these enzymes in the maturation and/or degradation of messenger RNA. This article is part of a Special Issue entitled: RNA Decay mechanisms.
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Affiliation(s)
- Zbigniew Dominski
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, USA
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25
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Cui H, Wang J. Machine Learning-Based Approaches Identify a Key Physicochemical Property for Accurately Predicting Polyadenlylation Signals in Genomic Sequences. INTELLIGENT COMPUTING THEORIES AND TECHNOLOGY 2013. [DOI: 10.1007/978-3-642-39482-9_32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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26
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Abstract
The mechanisms that maintain the stability of chromosome ends have broad impact on genome integrity in all eukaryotes. Budding yeast is a premier organism for telomere studies. Many fundamental concepts of telomere and telomerase function were first established in yeast and then extended to other organisms. We present a comprehensive review of yeast telomere biology that covers capping, replication, recombination, and transcription. We think of it as yeast telomeres—soup to nuts.
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Le Martelot G, Canella D, Symul L, Migliavacca E, Gilardi F, Liechti R, Martin O, Harshman K, Delorenzi M, Desvergne B, Herr W, Deplancke B, Schibler U, Rougemont J, Guex N, Hernandez N, Naef F. Genome-wide RNA polymerase II profiles and RNA accumulation reveal kinetics of transcription and associated epigenetic changes during diurnal cycles. PLoS Biol 2012; 10:e1001442. [PMID: 23209382 PMCID: PMC3507959 DOI: 10.1371/journal.pbio.1001442] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 10/25/2012] [Indexed: 01/01/2023] Open
Abstract
Genome-wide rhythms in RNA polymerase II loading and dynamic chromatin remodeling underlie periodic gene expression during diurnal cycles in the mouse liver. Interactions of cell-autonomous circadian oscillators with diurnal cycles govern the temporal compartmentalization of cell physiology in mammals. To understand the transcriptional and epigenetic basis of diurnal rhythms in mouse liver genome-wide, we generated temporal DNA occupancy profiles by RNA polymerase II (Pol II) as well as profiles of the histone modifications H3K4me3 and H3K36me3. We used these data to quantify the relationships of phases and amplitudes between different marks. We found that rhythmic Pol II recruitment at promoters rather than rhythmic transition from paused to productive elongation underlies diurnal gene transcription, a conclusion further supported by modeling. Moreover, Pol II occupancy preceded mRNA accumulation by 3 hours, consistent with mRNA half-lives. Both methylation marks showed that the epigenetic landscape is highly dynamic and globally remodeled during the 24-hour cycle. While promoters of transcribed genes had tri-methylated H3K4 even at their trough activity times, tri-methylation levels reached their peak, on average, 1 hour after Pol II. Meanwhile, rhythms in tri-methylation of H3K36 lagged transcription by 3 hours. Finally, modeling profiles of Pol II occupancy and mRNA accumulation identified three classes of genes: one showing rhythmicity both in transcriptional and mRNA accumulation, a second class with rhythmic transcription but flat mRNA levels, and a third with constant transcription but rhythmic mRNAs. The latter class emphasizes widespread temporally gated posttranscriptional regulation in the mouse liver. In mammalian organs such as the liver, many metabolic and physiological processes occur preferentially at specific times during the 24-hour daily cycle. The timing of these rhythmic functions depends on a complex interplay between the endogenous circadian clock and environmental timing cues relayed through the master circadian clock in the suprachiasmatic nucleus, or via feeding rhythms. These rhythms can be implemented on several regulatory levels, and here we aimed at a better understanding of the transcriptional and epigenetic changes that regulate diurnal rhythms. We performed genome-wide analysis of the locations of RNA polymerase II (Pol II) and the epigenetic histone modifications H3K4me3 and H3K36me3 at specific times of day, relating these data to mRNA expression levels. Our analyses show that Pol II transcriptional rhythms are biphasic in mouse liver, having predominant peak activities in the morning and evening. Moreover, dynamic changes in histone marks lag transcription rhythms genome-wide, indicating that the epigenetic landscape can be remodeled during the 24-hour cycle. Finally, a quantitative analysis of temporal Pol II and mRNA accumulation profiles indicates that posttranscriptional regulation significantly contributes to the amplitude and phase of mRNA accumulation profiles. While many studies have analyzed how transcription and chromatin states are modified during irreversible cell differentiation processes, our work highlights how these states can evolve reversibly in a system exhibiting periodicity in time.
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Affiliation(s)
| | - Donatella Canella
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Laura Symul
- The Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Eugenia Migliavacca
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Federica Gilardi
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Robin Liechti
- Vital IT, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Olivier Martin
- Vital IT, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Keith Harshman
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Mauro Delorenzi
- Département de Formation et de Recherche, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Winship Herr
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Bart Deplancke
- The Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ueli Schibler
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - Jacques Rougemont
- Bioinformatics and Biostatistics Core Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Nicolas Guex
- Vital IT, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Nouria Hernandez
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
- * E-mail: (NH); (FN)
| | - Felix Naef
- The Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- * E-mail: (NH); (FN)
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Jasnovidova O, Stefl R. The CTD code of RNA polymerase II: a structural view. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 4:1-16. [DOI: 10.1002/wrna.1138] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Mechanisms of HIV Transcriptional Regulation and Their Contribution to Latency. Mol Biol Int 2012; 2012:614120. [PMID: 22701796 PMCID: PMC3371693 DOI: 10.1155/2012/614120] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 04/09/2012] [Indexed: 12/26/2022] Open
Abstract
Long-lived latent HIV-infected cells lead to the rebound of virus replication following antiretroviral treatment interruption and present a major barrier to eliminating HIV infection. These latent reservoirs, which include quiescent memory T cells and tissue-resident macrophages, represent a subset of cells with decreased or inactive proviral transcription. HIV proviral transcription is regulated at multiple levels including transcription initiation, polymerase recruitment, transcription elongation, and chromatin organization. How these biochemical processes are coordinated and their potential role in repressing HIV transcription along with establishing and maintaining latency are reviewed.
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Krzyszton M, Zakrzewska-Placzek M, Koper M, Kufel J. Rat1 and Xrn2: The Diverse Functions of the Nuclear Rat1/Xrn2 Exonuclease. EUKARYOTIC RNASES AND THEIR PARTNERS IN RNA DEGRADATION AND BIOGENESIS, PART A 2012; 31:131-63. [DOI: 10.1016/b978-0-12-404740-2.00007-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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31
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Greive SJ, Dyer BA, Weitzel SE, Goodarzi JP, Main LJ, von Hippel PH. Fitting experimental transcription data with a comprehensive template-dependent modular kinetic model. Biophys J 2011; 101:1166-74. [PMID: 21889454 DOI: 10.1016/j.bpj.2011.07.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 06/20/2011] [Accepted: 07/22/2011] [Indexed: 11/19/2022] Open
Abstract
In the companion article, we developed a modular scheme for representing the kinetics of transcription elongation by RNA polymerase. As an example of how to use these approaches, in this article we use a comprehensive modular model of this sort to fit experimental transcript elongation results obtained on the canonical tR2 template of phage λ by means of complementary bulk gel electrophoresis and surface plasmon resonance assays. The gel electrophoresis results, obtained in experiments quenched at various times after initiation of transcription, provide distributions of RNA lengths as a function of time. The surface plasmon resonance methods were used to monitor increases and decreases in the total mass of transcription elongation complexes in the same experiments. The different measures of transcription dynamics that these methods provide allow us to use them in combination to obtain a set of largely robust and well-defined kinetic parameters. The results show that our modular approach can be used to develop and test predictive kinetic schemes that can be fit to real transcription elongation data. They also suggest that these approaches can be extended to simulate the kinetics of other processes that involve the processive extension or shortening of nucleic acid chains and related systems of sequential branching reaction events.
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Affiliation(s)
- Sandra J Greive
- Institute of Molecular Biology and Department of Chemistry, University of Oregon, Eugene, Oregon, USA
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32
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Development of a "modular" scheme to describe the kinetics of transcript elongation by RNA polymerase. Biophys J 2011; 101:1155-65. [PMID: 21889453 DOI: 10.1016/j.bpj.2011.07.042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 06/20/2011] [Accepted: 07/22/2011] [Indexed: 11/22/2022] Open
Abstract
Transcript elongation by RNA polymerase involves the sequential appearance of several alternative and off-pathway states of the transcript elongation complex (TEC), and this complicates modeling of the kinetics of the transcription elongation process. Based on solutions of the chemical master equation for such transcription systems as a function of time, we here develop a modular scheme for simulating such kinetic transcription data. This scheme deals explicitly with the problem of TEC desynchronization as transcript synthesis proceeds, and develops kinetic modules to permit the various alternative states of the TECs (paused states, backtracked states, arrested states, and terminated states) to be introduced one-by-one as needed. In this way, we can set up a comprehensive kinetic model of appropriate complexity to fit the known transcriptional properties of any given DNA template and set of experimental conditions, including regulatory cofactors. In the companion article, this modular scheme is successfully used to model kinetic transcription elongation data obtained by bulk-gel electrophoresis quenching procedures and real-time surface plasmon resonance methods from a template of known sequence that contains defined pause, stall, and termination sites.
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33
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García-Oliver E, García-Molinero V, Rodríguez-Navarro S. mRNA export and gene expression: the SAGA-TREX-2 connection. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1819:555-65. [PMID: 22178374 DOI: 10.1016/j.bbagrm.2011.11.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 01/07/2023]
Abstract
In the gene expression field, different steps have been traditionally viewed as discrete and unconnected events. Nowadays, genetic and functional studies support the model of a coupled network of physical and functional connections to carry out mRNA biogenesis. Gene expression is a coordinated process that comprises different linked steps like transcription, RNA processing, export to the cytoplasm, translation and degradation of mRNAs. Its regulation is essential for cellular survival and can occur at many different levels. Transcription is the central function that occurs in the nucleus, and RNAPII plays an essential role in mRNA biogenesis. During transcription, nascent mRNA is associated with the mRNA-binding proteins involved in processing and export of the mRNA particle. Cells have developed a network of multi-protein complexes whose functions regulate the different factors involved both temporally and spatially. This coupling mechanism acts as a quality control to solve some of the organization problems of gene expression in vivo, where all the factors implicated ensure that mRNAs are ready to be exported and translated. In this review, we focus on the functional coupling of gene transcription and mRNA export, and place particular emphasis on the relationship between the NPC-associated complex, TREX2, and the transcription co-activator, SAGA. We have pinpointed the experimental evidence for Sus1's roles in transcription initiation, transcription elongation and mRNA export. In addition, we have reviewed other NPC-related processes such as gene gating to the nuclear envelope, the chromatin structure and the cellular context in which these processes take place. This article is part of a Special Issue entitled: Nuclear Transport and RNA Processing.
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Affiliation(s)
- Encar García-Oliver
- Centro de Investigación Príncipe Felipe (CIPF), Gene Expression coupled with RNA Transport Laboratory, Valencia, Spain
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34
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Crisucci EM, Arndt KM. The Roles of the Paf1 Complex and Associated Histone Modifications in Regulating Gene Expression. GENETICS RESEARCH INTERNATIONAL 2011; 2011. [PMID: 22408743 PMCID: PMC3296560 DOI: 10.4061/2011/707641] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The conserved Paf1 complex (Paf1C) carries out multiple functions during transcription by RNA polymerase (pol) II, and these functions are required for the proper expression of numerous genes in yeast and metazoans. In the elongation stage of the transcription cycle, the Paf1C associates with RNA pol II, interacts with other transcription elongation factors, and facilitates modifications to the chromatin template. At the end of elongation, the Paf1C plays an important role in the termination of RNA pol II transcripts and the recruitment of proteins required for proper RNA 3′ end formation. Significantly, defects in the Paf1C are associated with several human diseases. In this paper, we summarize current knowledge on the roles of the Paf1C in RNA pol II transcription.
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Affiliation(s)
- Elia M Crisucci
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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35
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Zaratiegui M, Castel SE, Irvine DV, Kloc A, Ren J, Li F, de Castro E, Marín L, Chang AY, Goto D, Cande WZ, Antequera F, Arcangioli B, Martienssen RA. RNAi promotes heterochromatic silencing through replication-coupled release of RNA Pol II. Nature 2011; 479:135-8. [PMID: 22002604 PMCID: PMC3391703 DOI: 10.1038/nature10501] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 08/25/2011] [Indexed: 11/25/2022]
Abstract
Heterochromatin comprises tightly compacted repetitive regions of eukaryotic chromosomes. The inheritance of heterochromatin through mitosis requires RNA interference (RNAi), which guides histone modification 1 during the DNA replication phase of the cell cycle2. Here, we show that the alternating arrangement of origins of replication and non-coding RNA in pericentromeric heterochromatin results in competition between transcription and replication. Co-transcriptional RNAi releases RNA polymerase II (PolII), allowing completion of DNA replication by the leading strand DNA polymerase, and associated histone modifying enzymes3 which spread heterochromatin with the replication fork. In the absence of RNAi, stalled forks are repaired by homologous recombination without histone modification.
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Affiliation(s)
- Mikel Zaratiegui
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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36
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Unravelling the means to an end: RNA polymerase II transcription termination. Nat Rev Mol Cell Biol 2011; 12:283-94. [PMID: 21487437 DOI: 10.1038/nrm3098] [Citation(s) in RCA: 198] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The pervasiveness of RNA synthesis in eukaryotes is largely the result of RNA polymerase II (Pol II)-mediated transcription, and termination of its activity is necessary to partition the genome and maintain the proper expression of neighbouring genes. Despite its ever-increasing biological significance, transcription termination remains one of the least understood processes in gene expression. However, recent mechanistic studies have revealed a striking convergence among several overlapping models of termination, including the poly(A)- and Sen1-dependent pathways, as well as new insights into the specificity of Pol II termination among its diverse gene targets. Broader knowledge of the role of Pol II carboxy-terminal domain phosphorylation in promoting alternative mechanisms of termination has also been gained.
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37
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38
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Honorine R, Mosrin-Huaman C, Hervouet-Coste N, Libri D, Rahmouni AR. Nuclear mRNA quality control in yeast is mediated by Nrd1 co-transcriptional recruitment, as revealed by the targeting of Rho-induced aberrant transcripts. Nucleic Acids Res 2010; 39:2809-20. [PMID: 21113025 PMCID: PMC3074134 DOI: 10.1093/nar/gkq1192] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The production of mature export-competent transcripts is under the surveillance of quality control steps where aberrant mRNP molecules resulting from inappropriate or inefficient processing and packaging reactions are subject to exosome-mediated degradation. Previously, we have shown that the heterologous expression of bacterial Rho factor in yeast interferes in normal mRNP biogenesis leading to the production of full-length yet aberrant transcripts that are degraded by the nuclear exosome with ensuing growth defect. Here, we took advantage of this new tool to investigate the molecular mechanisms by which an integrated system recognizes aberrancies at each step of mRNP biogenesis and targets the defective molecules for destruction. We show that the targeting and degradation of Rho-induced aberrant transcripts is associated with a large increase of Nrd1 recruitment to the transcription complex via its CID and RRM domains and a concomitant enrichment of exosome component Rrp6 association. The targeting and degradation of the aberrant transcripts is suppressed by the overproduction of Pcf11 or its isolated CID domain, through a competition with Nrd1 for recruitment by the transcription complex. Altogether, our results support a model in which a stimulation of Nrd1 co-transcriptional recruitment coordinates the recognition and removal of aberrant transcripts by promoting the attachment of the nuclear mRNA degradation machinery.
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Affiliation(s)
- Romy Honorine
- Centre de Biophysique Moléculaire, UPR 4301 du CNRS, Rue Charles Sadron, 45071 Orléans, France
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39
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Mor A, Ben-Yishay R, Shav-Tal Y. On the right track: following the nucleo-cytoplasmic path of an mRNA. Nucleus 2010; 1:492-8. [PMID: 21327092 DOI: 10.4161/nucl.1.6.13515] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 09/03/2010] [Indexed: 11/19/2022] Open
Abstract
The transcription machinery in the eukaryotic nucleus generates messenger RNA molecules that translocate through the nucleoplasm, anchor to a nuclear pore, and find their way out into the cytoplasm. The dynamic aspects of these steps in the expression pathway were examined in order to understand the kinetic time-frames of gene activation and message dissemination. Utilizing live-cell imaging and tracking of single mRNPs containing different sized mRNAs and varying numbers of introns and exons, it was possible to quantify the temporal and spatial characteristics of the nucleoplasmic travels of mRNPs as well as the kinetics of translocation through the nuclear pore.
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Affiliation(s)
- Amir Mor
- The Mina & Everard Goodman Faculty of Life Sciences & Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, Israel
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40
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Dominski Z. The hunt for the 3' endonuclease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 1:325-40. [PMID: 21935893 DOI: 10.1002/wrna.33] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pre-mRNAs are typically processed at the 3(') end by cleavage/polyadenylation. This is a two-step processing reaction initiated by endonucleolytic cleavage of pre-mRNAs downstream of the AAUAAA sequence or its variant, followed by extension of the newly generated 3(') end with a poly(A) tail. In metazoans, replication-dependent histone transcripts are cleaved by a different 3(') end processing mechanism that depends on the U7 small nuclear ribonucleoprotein and the polyadenylation step is omitted. Each of the two mechanisms occurs in a macromolecular assembly that primarily functions to juxtapose the scissile bond with the 3(') endonuclease. Remarkably, despite characterizing a number of processing factors, the identity of this most critical component remained elusive until recently. For cleavage coupled to polyadenylation, much needed help was offered by bioinformatics, which pointed to CPSF-73, a known processing factor required for both cleavage and polyadenylation, as the possible 3(') endonuclease. In silico structural analysis indicated that this protein is a member of the large metallo-β-lactamase family of hydrolytic enzymes and belongs to the β-CASP subfamily that includes several RNA and DNA-specific nucleases. Subsequent experimental studies supported the notion that CPSF-73 does function as the endonuclease in the formation of polyadenylated mRNAs, but some controversy still remains as a different cleavage and polyadenylation specificity factor (CPSF) subunit, CPSF-30, displays an endonuclease activity in vitro while recombinant CPSF-73 is inactive. Unexpectedly, CPSF-73 as the 3(') endonuclease in cleavage coupled to polyadenylation found a strong ally in U7-dependent processing of histone pre-mRNAs, which was shown to utilize the same protein as the cleaving enzyme. It thus seems likely that these two processing reactions evolved from a common mechanism, with CPSF-73 as the endonuclease.
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Affiliation(s)
- Zbigniew Dominski
- Department of Biochemistry and Biophysics and Program in Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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41
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RNA polymerase II C-terminal domain phosphorylation patterns in Caenorhabditis elegans operons, polycistronic gene clusters with only one promoter. Mol Cell Biol 2010; 30:3887-93. [PMID: 20498277 DOI: 10.1128/mcb.00325-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The heptad repeat of the RNA polymerase II (RNAPII) C-terminal domain is phosphorylated at serine 5 near gene 5' ends and serine 2 near 3' ends in order to recruit pre-mRNA processing factors. Ser-5(P) is associated with gene 5' ends to recruit capping enzymes, whereas Ser-2(P) is associated with gene 3' ends to recruit cleavage and polyadenylation factors. In the gene clusters called operons in Caenorhabditis elegans, there is generally only a single promoter, but each gene in the operon forms a 3' end by the usual mechanism. Although downstream operon genes have 5' ends, they receive their caps by trans splicing rather than by capping enzymes. Thus, they are predicted to not need Ser-5 phosphorylation. Here we show by RNAPII chromatin immunoprecipitation (ChIP) that internal operon gene 5' ends do indeed lack Ser-5(P) peaks. In contrast, Ser-2(P) peaks occur at each mRNA 3' end, where the 3'-end formation machinery binds. These results provide additional support for the idea that the serine phosphorylation of the C-terminal domain (CTD) serves to bring RNA-processing enzymes to the transcription complex. Furthermore, these results provide a novel demonstration that genes in operons are cotranscribed from a single upstream promoter.
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Jaehning JA. The Paf1 complex: platform or player in RNA polymerase II transcription? BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:379-88. [PMID: 20060942 DOI: 10.1016/j.bbagrm.2010.01.001] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 12/31/2009] [Accepted: 01/04/2010] [Indexed: 12/01/2022]
Abstract
The Paf1 complex (Paf1C), composed of the proteins Paf1, Ctr9, Cdc73, Rtf1, and Leo1, accompanies RNA polymerase II (pol II) from the promoter to the 3' end formation site of mRNA and snoRNA encoding genes; it is also found associated with RNA polymerase I (pol I) on rDNA. The Paf1C is found in simple and complex eukaryotes; in human cells hSki8 is also part of the complex. The Paf1C has been linked to a large and growing list of transcription related processes including: communication with transcriptional activators; recruitment and activation of histone modification factors; facilitation of elongation on chromatin templates; and the recruitment of 3' end-processing factors necessary for accurate termination of transcription. Absence of, or mutations in, Paf1C factors result in alterations in gene expression that can result in misregulation of developmental programs and loss of control of cell division leading to cancer in humans. This review considers recent information that may help to resolve whether the Paf1C is primarily a "platform" on pol II that coordinates the association of many critical transcription factors, or if the complex itself plays a more direct role in one or more steps in transcription.
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Affiliation(s)
- Judith A Jaehning
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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43
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Millevoi S, Vagner S. Molecular mechanisms of eukaryotic pre-mRNA 3' end processing regulation. Nucleic Acids Res 2009; 38:2757-74. [PMID: 20044349 PMCID: PMC2874999 DOI: 10.1093/nar/gkp1176] [Citation(s) in RCA: 294] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Messenger RNA (mRNA) 3′ end formation is a nuclear process through which all eukaryotic primary transcripts are endonucleolytically cleaved and most of them acquire a poly(A) tail. This process, which consists in the recognition of defined poly(A) signals of the pre-mRNAs by a large cleavage/polyadenylation machinery, plays a critical role in gene expression. Indeed, the poly(A) tail of a mature mRNA is essential for its functions, including stability, translocation to the cytoplasm and translation. In addition, this process serves as a bridge in the network connecting the different transcription, capping, splicing and export machineries. It also participates in the quantitative and qualitative regulation of gene expression in a variety of biological processes through the selection of single or alternative poly(A) signals in transcription units. A large number of protein factors associates with this machinery to regulate the efficiency and specificity of this process and to mediate its interaction with other nuclear events. Here, we review the eukaryotic 3′ end processing machineries as well as the comprehensive set of regulatory factors and discuss the different molecular mechanisms of 3′ end processing regulation by proposing several overlapping models of regulation.
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Affiliation(s)
- Stefania Millevoi
- Institut National de la Santé et de la Recherche Médicale U563, Toulouse, F-31000, France.
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44
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Nergadze SG, Farnung BO, Wischnewski H, Khoriauli L, Vitelli V, Chawla R, Giulotto E, Azzalin CM. CpG-island promoters drive transcription of human telomeres. RNA (NEW YORK, N.Y.) 2009; 15:2186-94. [PMID: 19850908 PMCID: PMC2779677 DOI: 10.1261/rna.1748309] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 09/03/2009] [Indexed: 05/22/2023]
Abstract
The longstanding dogma that telomeres, the heterochromatic extremities of linear eukaryotic chromosomes, are transcriptionally silent was overturned by the discovery that DNA-dependent RNA polymerase II (RNAPII) transcribes telomeric DNA into telomeric repeat-containing RNA (TERRA). Here, we show that CpG dinucleotide-rich DNA islands, shared among multiple human chromosome ends, promote transcription of TERRA molecules. TERRA promoters sustain cellular expression of reporter genes, are located immediately upstream of TERRA transcription start sites, and are bound by active RNAPII in vivo. Finally, the identified promoter CpG dinucleotides are methylated in vivo, and cytosine methylation negatively regulates TERRA abundance. The existence of subtelomeric promoters, driving TERRA transcription from independent chromosome ends, supports the idea that TERRA exerts fundamental functions in the context of telomere biology.
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Affiliation(s)
- Solomon G Nergadze
- Dipartimento di Genetica e Microbiologia Adriano Buzzati-Traverso, Università di Pavia, 2700 Pavia, Italy
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45
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Perales R, Bentley D. "Cotranscriptionality": the transcription elongation complex as a nexus for nuclear transactions. Mol Cell 2009; 36:178-91. [PMID: 19854129 DOI: 10.1016/j.molcel.2009.09.018] [Citation(s) in RCA: 286] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Revised: 07/07/2009] [Accepted: 08/06/2009] [Indexed: 12/27/2022]
Abstract
Much of the complex process of RNP biogenesis takes place at the gene cotranscriptionally. The target for RNA binding and processing factors is, therefore, not a solitary RNA molecule but, rather, a transcription elongation complex (TEC) comprising the growing nascent RNA and RNA polymerase traversing a chromatin template with associated passenger proteins. RNA maturation factors are not the only nuclear machines whose work is organized cotranscriptionally around the TEC scaffold. Additionally, DNA repair, covalent chromatin modification, "gene gating" at the nuclear pore, Ig gene hypermutation, and sister chromosome cohesion have all been demonstrated or suggested to involve a cotranscriptional component. From this perspective, TECs can be viewed as potent "community organizers" within the nucleus.
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Affiliation(s)
- Roberto Perales
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, UCHSC, MS8101, P.O. Box 6511, Aurora CO, 80045, USA
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Omberg L, Meyerson JR, Kobayashi K, Drury LS, Diffley JFX, Alter O. Global effects of DNA replication and DNA replication origin activity on eukaryotic gene expression. Mol Syst Biol 2009; 5:312. [PMID: 19888207 PMCID: PMC2779084 DOI: 10.1038/msb.2009.70] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Accepted: 08/19/2009] [Indexed: 11/09/2022] Open
Abstract
This report provides a global view of how gene expression is affected by DNA replication. We analyzed synchronized cultures of Saccharomyces cerevisiae under conditions that prevent DNA replication initiation without delaying cell cycle progression. We use a higher-order singular value decomposition to integrate the global mRNA expression measured in the multiple time courses, detect and remove experimental artifacts and identify significant combinations of patterns of expression variation across the genes, time points and conditions. We find that, first, approximately 88% of the global mRNA expression is independent of DNA replication. Second, the requirement of DNA replication for efficient histone gene expression is independent of conditions that elicit DNA damage checkpoint responses. Third, origin licensing decreases the expression of genes with origins near their 3' ends, revealing that downstream origins can regulate the expression of upstream genes. This confirms previous predictions from mathematical modeling of a global causal coordination between DNA replication origin activity and mRNA expression, and shows that mathematical modeling of DNA microarray data can be used to correctly predict previously unknown biological modes of regulation.
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Affiliation(s)
- Larsson Omberg
- Department of Biomedical Engineering, University of Texas, Austin, TX 78712, USA
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Hager GL, McNally JG, Misteli T. Transcription dynamics. Mol Cell 2009; 35:741-53. [PMID: 19782025 DOI: 10.1016/j.molcel.2009.09.005] [Citation(s) in RCA: 355] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 09/08/2009] [Indexed: 01/09/2023]
Abstract
All aspects of transcription and its regulation involve dynamic events. The basal transcription machinery and regulatory components are dynamically recruited to their target genes, and dynamic interactions of transcription factors with chromatin--and with each other--play a key role in RNA polymerase assembly, initiation, and elongation. These short-term binding dynamics of transcription factors are superimposed by long-term cyclical behavior of chromatin opening and transcription factor-binding events. Its dynamic nature is not only a fundamental property of the transcription machinery, but it is emerging as an important modulator of physiological processes, particularly in differentiation and development.
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Affiliation(s)
- Gordon L Hager
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Haenni S, Sharpe HE, Gravato Nobre M, Zechner K, Browne C, Hodgkin J, Furger A. Regulation of transcription termination in the nematode Caenorhabditis elegans. Nucleic Acids Res 2009; 37:6723-36. [PMID: 19740764 PMCID: PMC2777434 DOI: 10.1093/nar/gkp744] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The current predicted mechanisms that describe RNA polymerase II (pol II) transcription termination downstream of protein expressing genes fail to adequately explain, how premature termination is prevented in eukaryotes that possess operon-like structures. Here we address this issue by analysing transcription termination at the end of single protein expressing genes and genes located within operons in the nematode Caenorhabditis elegans. By using a combination of RT-PCR and ChIP analysis we found that pol II generally transcribes up to 1 kb past the poly(A) sites into the 3' flanking regions of the nematode genes before it terminates. We also show that pol II does not terminate after transcription of internal poly(A) sites in operons. We provide experimental evidence that five randomly chosen C. elegans operons are transcribed as polycistronic pre-mRNAs. Furthermore, we show that cis-splicing of the first intron located in downstream positioned genes in these polycistronic pre-mRNAs is critical for their expression and may play a role in preventing premature pol II transcription termination.
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Affiliation(s)
- Simon Haenni
- Genetics Unit, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
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Fast ribozyme cleavage releases transcripts from RNA polymerase II and aborts co-transcriptional pre-mRNA processing. Nat Struct Mol Biol 2009; 16:916-22. [PMID: 19701200 PMCID: PMC2755206 DOI: 10.1038/nsmb.1652] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 06/29/2009] [Indexed: 02/06/2023]
Abstract
We investigated whether a continuous transcript is necessary for co-transcriptional pre-mRNA processing. Cutting an intron with the fast-cleaving hepatitis delta ribozyme, but not the slower hammerhead, inhibited splicing. Therefore, exon tethering to RNA polymerase II (Pol II) cannot rescue splicing of a transcript severed by a ribozyme that cleaves rapidly relative to the rate of splicing. Ribozyme cutting also released cap-binding complex (CBC) from the gene, suggesting that exon 1 is not tethered. Unexpectedly, cutting within exons inhibited splicing of distal introns, where exon definition is not affected, probably owing to disruption of the interactions with the CBC and the Pol II C-terminal domain that facilitate splicing. Ribozyme cutting within the mRNA also inhibited 3' processing and transcription termination. We propose that damaging the nascent transcript aborts pre-mRNA processing and that this mechanism may help to prevent association of processing factors with Pol II that is not productively engaged in transcription.
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50
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Sgourou A, Routledge S, Spathas D, Athanassiadou A, Antoniou MN. Physiological levels of HBB transgene expression from S/MAR element-based replicating episomal vectors. J Biotechnol 2009; 143:85-94. [DOI: 10.1016/j.jbiotec.2009.06.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 03/22/2009] [Accepted: 06/16/2009] [Indexed: 01/29/2023]
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