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Wiedermannová J, Krásný L. β-CASP proteins removing RNA polymerase from DNA: when a torpedo is needed to shoot a sitting duck. Nucleic Acids Res 2021; 49:10221-10234. [PMID: 34551438 PMCID: PMC8501993 DOI: 10.1093/nar/gkab803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022] Open
Abstract
During the first step of gene expression, RNA polymerase (RNAP) engages DNA to transcribe RNA, forming highly stable complexes. These complexes need to be dissociated at the end of transcription units or when RNAP stalls during elongation and becomes an obstacle (‘sitting duck’) to further transcription or replication. In this review, we first outline the mechanisms involved in these processes. Then, we explore in detail the torpedo mechanism whereby a 5′–3′ RNA exonuclease (torpedo) latches itself onto the 5′ end of RNA protruding from RNAP, degrades it and upon contact with RNAP, induces dissociation of the complex. This mechanism, originally described in Eukaryotes and executed by Xrn-type 5′–3′ exonucleases, was recently found in Bacteria and Archaea, mediated by β-CASP family exonucleases. We discuss the mechanistic aspects of this process across the three kingdoms of life and conclude that 5′–3′ exoribonucleases (β-CASP and Xrn families) involved in the ancient torpedo mechanism have emerged at least twice during evolution.
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Affiliation(s)
- Jana Wiedermannová
- Correspondence may also be addressed to Jana Wiedermannová. Tel: +44 191 208 3226; Fax: +44 191 208 3205;
| | - Libor Krásný
- To whom correspondence should be addressed. Tel: +420 241063208;
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2
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A SUMO-dependent pathway controls elongating RNA Polymerase II upon UV-induced damage. Sci Rep 2019; 9:17914. [PMID: 31784551 PMCID: PMC6884465 DOI: 10.1038/s41598-019-54027-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/30/2019] [Indexed: 02/01/2023] Open
Abstract
RNA polymerase II (RNAPII) is the workhorse of eukaryotic transcription and produces messenger RNAs and small nuclear RNAs. Stalling of RNAPII caused by transcription obstacles such as DNA damage threatens functional gene expression and is linked to transcription-coupled DNA repair. To restore transcription, persistently stalled RNAPII can be disassembled and removed from chromatin. This process involves several ubiquitin ligases that have been implicated in RNAPII ubiquitylation and proteasomal degradation. Transcription by RNAPII is heavily controlled by phosphorylation of the C-terminal domain of its largest subunit Rpb1. Here, we show that the elongating form of Rpb1, marked by S2 phosphorylation, is specifically controlled upon UV-induced DNA damage. Regulation of S2-phosphorylated Rpb1 is mediated by SUMOylation, the SUMO-targeted ubiquitin ligase Slx5-Slx8, the Cdc48 segregase as well as the proteasome. Our data suggest an RNAPII control pathway with striking parallels to known disassembly mechanisms acting on defective RNA polymerase III.
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3
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Chiou YY, Hu J, Sancar A, Selby CP. RNA polymerase II is released from the DNA template during transcription-coupled repair in mammalian cells. J Biol Chem 2017; 293:2476-2486. [PMID: 29282293 DOI: 10.1074/jbc.ra117.000971] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 12/19/2017] [Indexed: 11/06/2022] Open
Abstract
In mammalian cells, bulky DNA adducts located in the template but not the coding strand of genes block elongation by RNA polymerase II (RNAPII). The blocked RNAPII targets these transcription-blocking adducts to undergo more rapid excision repair than adducts located elsewhere in the genome. In excision repair, coupled incisions are made in the damaged DNA strand on both sides of the adduct. The fate of RNAPII in the course of this transcription-coupled repair (TCR) pathway is unclear. To address the fate of RNAPII, we used methods that control transcription to initiate a discrete "wave" of elongation complexes. Analyzing genome-wide transcription and repair by next-generation sequencing, we identified locations of elongation complexes and transcription-repair coupling events in genes throughout the genome. Using UV-exposed human skin fibroblasts, we found that, at the dose used, a single wave of elongation complexes was blocked within the first 25 kb of genes. TCR occurred where the elongation complexes were blocked, and repair was associated with the dissociation of these complexes. These results indicate that individual elongation complexes do not engage in multiple rounds of TCR with successive lesions. Our results are consistent with a model in which RNAPII is dissociated after the dual incision of the transcription-blocking lesion, perhaps by Cockayne syndrome group B translocase, or during the synthesis of a repair patch.
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Affiliation(s)
- Yi-Ying Chiou
- From the Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7260 and.,the Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan
| | - Jinchuan Hu
- From the Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7260 and
| | - Aziz Sancar
- From the Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7260 and
| | - Christopher P Selby
- From the Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7260 and
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4
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Peyresaubes F, Zeledon C, Guintini L, Charton R, Muguet A, Conconi A. RNA Polymerase-I-Dependent Transcription-coupled Nucleotide Excision Repair of UV-Induced DNA Lesions at Transcription Termination Sites, in Saccharomyces cerevisiae. Photochem Photobiol 2017; 93:363-374. [PMID: 27935059 DOI: 10.1111/php.12690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/16/2016] [Indexed: 11/28/2022]
Abstract
If not repaired, ultraviolet light-induced DNA damage can lead to genome instability. Nucleotide excision repair (NER) of UV photoproducts is generally fast in the coding region of genes, where RNA polymerase-II (RNAP2) arrest at damage sites and trigger transcription-coupled NER (TC-NER). In Saccharomyces cerevisiae, there is RNA polymerase-I (RNAP1)-dependent TC-NER, but this process remains elusive. Therefore, we wished to characterize TC-NER efficiency in different regions of the rDNA locus: where RNAP1 are present at high density and start transcription elongation, where the elongation rate is slow, and in the transcription terminator where RNAP1 pause, accumulate and then are released. The Rpa12 subunit of RNAP1 and the Nsi1 protein participate in transcription termination, and NER efficiency was compared between wild type and cells lacking Rpa12 or Nsi1. The presence of RNAP1 was determined by chromatin endogenous cleavage and chromatin immunoprecipitation, and repair was followed at nucleotide precision with an assay that is based on the blockage of Taq polymerase by UV photoproducts. We describe that TC-NER, which is modulated by the RNAP1 level and elongation rate, ends at the 35S rRNA gene transcription termination site.
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Affiliation(s)
- François Peyresaubes
- Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Carlos Zeledon
- Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Laetitia Guintini
- Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Romain Charton
- Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Alexia Muguet
- Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Antonio Conconi
- Département de Microbiologie et Infectiologie, Université de Sherbrooke, Sherbrooke, QC, Canada
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5
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Charton R, Guintini L, Peyresaubes F, Conconi A. Repair of UV induced DNA lesions in ribosomal gene chromatin and the role of "Odd" RNA polymerases (I and III). DNA Repair (Amst) 2015; 36:49-58. [PMID: 26411875 DOI: 10.1016/j.dnarep.2015.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In fast growing eukaryotic cells, a subset of rRNA genes are transcribed at very high rates by RNA polymerase I (RNAPI). Nuclease digestion-assays and psoralen crosslinking have shown that they are open; that is, largely devoid of nucleosomes. In the yeast Saccharomyces cerevisae, nucleotide excision repair (NER) and photolyase remove UV photoproducts faster from open rRNA genes than from closed and nucleosome-loaded inactive rRNA genes. After UV irradiation, rRNA transcription declines because RNAPI halt at UV photoproducts and are then displaced from the transcribed strand. When the DNA lesion is quickly recognized by NER, it is the sub-pathway transcription-coupled TC-NER that removes the UV photoproduct. If dislodged RNAPI are replaced by nucleosomes before NER recognizes the lesion, then it is the sub-pathway global genome GG-NER that removes the UV photoproducts from the transcribed strand. Also, GG-NER maneuvers in the non-transcribed strand of open genes and in both strands of closed rRNA genes. After repair, transcription resumes and elongating RNAPI reopen the rRNA gene. In higher eukaryotes, NER in rRNA genes is inefficient and there is no evidence for TC-NER. Moreover, TC-NER does not occur in RNA polymerase III transcribed genes of both, yeast and human fibroblast.
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Affiliation(s)
- Romain Charton
- Département de Microbiologie et Infectiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - Laetitia Guintini
- Département de Microbiologie et Infectiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - François Peyresaubes
- Département de Microbiologie et Infectiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada
| | - Antonio Conconi
- Département de Microbiologie et Infectiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada.
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6
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Affiliation(s)
- Jiannan Guo
- Biochemistry Department, University of Iowa , Iowa City, Iowa 52242, United States
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7
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Tremblay M, Charton R, Wittner M, Levasseur G, Griesenbeck J, Conconi A. UV light-induced DNA lesions cause dissociation of yeast RNA polymerases-I and establishment of a specialized chromatin structure at rRNA genes. Nucleic Acids Res 2013; 42:380-95. [PMID: 24097442 PMCID: PMC3874186 DOI: 10.1093/nar/gkt871] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The cytotoxicity of UV light-induced DNA lesions results from their interference with transcription and replication. DNA lesions arrest elongating RNA polymerases, an event that triggers transcription-coupled nucleotide excision repair. Since arrested RNA polymerases reduce the accessibility of repair factors to DNA lesions, they might be displaced. The fate of arrested RNA polymerases-II at DNA lesions has been extensively studied, yielding partially contradictory results. Considerably less is known about RNA polymerases-I that transcribe nucleosomes-depleted rRNA genes at very high rate. To investigate the fate of arrested RNA polymerases-I at DNA lesions, chromatin-immunoprecipitation, electron microscopy, transcription run-on, psoralen-cross-linking and chromatin-endogenous cleavage were employed. We found that RNA polymerases-I density increased at the 5′-end of the gene, likely due to continued transcription initiation followed by elongation and pausing/release at the first DNA lesion. Most RNA polymerases-I dissociated downstream of the first DNA lesion, concomitant with chromatin closing that resulted from deposition of nucleosomes. Although nucleosomes were deposited, the high mobility group-box Hmo1 (component of actively transcribed rRNA genes) remained associated. After repair of DNA lesions, Hmo1 containing chromatin might help to restore transcription elongation and reopening of rRNA genes chromatin.
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Affiliation(s)
- Maxime Tremblay
- Département de Microbiologie et Infectiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada and Institut für Biochemie, Genetik und Mikrobiologie, Universität Regensburg, 93053 Regensburg, Germany
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8
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Kazerouninia A, Ngo B, Martinson HG. Poly(A) signal-dependent degradation of unprocessed nascent transcripts accompanies poly(A) signal-dependent transcriptional pausing in vitro. RNA (NEW YORK, N.Y.) 2010; 16:197-210. [PMID: 19926725 PMCID: PMC2802029 DOI: 10.1261/rna.1622010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Accepted: 09/22/2009] [Indexed: 05/28/2023]
Abstract
The poly(A) signal has long been known for its role in directing the cleavage and polyadenylation of eukaryotic mRNA. In recent years its additional coordinating role in multiple related aspects of gene expression has also become increasingly clear. Here we use HeLa nuclear extracts to study two of these activities, poly(A) signal-dependent transcriptional pausing, which was originally proposed as a surveillance checkpoint, and poly(A) signal-dependent degradation (PDD) of unprocessed transcripts from weak poly(A) signals. We confirm directly, by measuring the length of RNA within isolated transcription elongation complexes, that a newly transcribed poly(A) signal reduces the rate of elongation by RNA polymerase II and causes the accumulation of elongation complexes downstream from the poly(A) signal. We then show that if the RNA in these elongation complexes contains a functional but unprocessed poly(A) signal, degradation of the transcripts ensues. The degradation depends on the unprocessed poly(A) signal being functional, and does not occur if a mutant poly(A) signal is used. We suggest that during normal 3'-end processing the uncleaved poly(A) signal continuously samples competing reaction pathways for processing and for degradation, and that in the case of weak poly(A) signals, where poly(A) site cleavage is slow, the default pathway to degradation predominates.
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Affiliation(s)
- Amir Kazerouninia
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90095-1569, USA
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9
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Tremblay M, Toussaint M, D'Amours A, Conconi A. Nucleotide excision repair and photolyase repair of UV photoproducts in nucleosomes: assessing the existence of nucleosome and non-nucleosome rDNA chromatin in vivo. Biochem Cell Biol 2009; 87:337-46. [PMID: 19234545 DOI: 10.1139/o08-128] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The genome is organized into nuclear domains, which create microenvironments that favor distinct chromatin structures and functions (e.g., highly repetitive sequences, centromeres, telomeres, noncoding sequences, inactive genes, RNA polymerase II and III transcribed genes, and the nucleolus). Correlations have been drawn between gene silencing and proximity to a heterochromatic compartment. At the other end of the scale are ribosomal genes, which are transcribed at a very high rate by RNA polymerase I (~60% of total transcription), have a loose chromatin structure, and are clustered in the nucleolus. The rDNA sequences have 2 distinct structures: active rRNA genes, which have no nucleosomes; and inactive rRNA genes, which have nucleosomes. Like DNA transcription and replication, DNA repair is modulated by the structure of chromatin, and the kinetics of DNA repair vary among the nuclear domains. Although research on DNA repair in all chromosomal contexts is important to understand the mechanisms of genome maintenance, this review focuses on nucleotide excision repair and photolyase repair of UV photoproducts in the first-order packing of DNA in chromatin: the nucleosome. In addition, it summarizes the studies that have demonstrated the existence of the 2 rDNA chromatins, and the way this feature of the rDNA locus allows for direct comparison of DNA repair in 2 very different structures: nucleosome and non-nucleosome DNA.
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Affiliation(s)
- Maxime Tremblay
- Departement de Microbiologie et Infectiologie, Faculte de Medecine, Universite de Sherbrooke, Sherbrooke, QCJ1H5N4, Canada
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10
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Affiliation(s)
- David S Gilmour
- Center for Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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11
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Affiliation(s)
- Yongwon Jung
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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12
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Lainé JP, Egly JM. When transcription and repair meet: a complex system. Trends Genet 2006; 22:430-6. [PMID: 16797777 DOI: 10.1016/j.tig.2006.06.006] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 04/11/2006] [Accepted: 06/06/2006] [Indexed: 01/03/2023]
Abstract
Transcription-coupled repair (TCR) is a mechanism that removes DNA lesions so that genes can be transcribed correctly. However, the sequence of events that results in a DNA lesion being repaired remains elusive. In this review, we illustrate the potential chain of events leading to the elimination of the damaged DNA and the proper resumption of transcription. We focus on the roles of CSA and CSB proteins, which, when mutated, impair TCR. Defective TCR is one of the features of Cockayne syndrome, a DNA-repair disorder.
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Affiliation(s)
- Jean-Philippe Lainé
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, BP 163, 67404 Illkirch Cedex, C. U. Strasbourg, France
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13
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Flaus A, Martin DMA, Barton GJ, Owen-Hughes T. Identification of multiple distinct Snf2 subfamilies with conserved structural motifs. Nucleic Acids Res 2006; 34:2887-905. [PMID: 16738128 PMCID: PMC1474054 DOI: 10.1093/nar/gkl295] [Citation(s) in RCA: 511] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 03/18/2006] [Accepted: 04/05/2006] [Indexed: 12/14/2022] Open
Abstract
The Snf2 family of helicase-related proteins includes the catalytic subunits of ATP-dependent chromatin remodelling complexes found in all eukaryotes. These act to regulate the structure and dynamic properties of chromatin and so influence a broad range of nuclear processes. We have exploited progress in genome sequencing to assemble a comprehensive catalogue of over 1300 Snf2 family members. Multiple sequence alignment of the helicase-related regions enables 24 distinct subfamilies to be identified, a considerable expansion over earlier surveys. Where information is known, there is a good correlation between biological or biochemical function and these assignments, suggesting Snf2 family motor domains are tuned for specific tasks. Scanning of complete genomes reveals all eukaryotes contain members of multiple subfamilies, whereas they are less common and not ubiquitous in eubacteria or archaea. The large sample of Snf2 proteins enables additional distinguishing conserved sequence blocks within the helicase-like motor to be identified. The establishment of a phylogeny for Snf2 proteins provides an opportunity to make informed assignments of function, and the identification of conserved motifs provides a framework for understanding the mechanisms by which these proteins function.
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Affiliation(s)
- Andrew Flaus
- Division of Gene Regulation and Expression, University of DundeeDundee DD1 5EH, Scotland, UK
- Bioinformatics and Computational Biology Research Group, School of Life Sciences, University of DundeeDundee DD1 5EH, Scotland, UK
| | - David M. A. Martin
- Bioinformatics and Computational Biology Research Group, School of Life Sciences, University of DundeeDundee DD1 5EH, Scotland, UK
| | - Geoffrey J. Barton
- Bioinformatics and Computational Biology Research Group, School of Life Sciences, University of DundeeDundee DD1 5EH, Scotland, UK
| | - Tom Owen-Hughes
- To whom correspondence should be addressed. Tel: +44 0 1382 385796; Fax: +44 0 1382 388702;
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14
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Huang JY, Chen WH, Chang YL, Wang HT, Chuang WT, Lee SC. Modulation of nucleosome-binding activity of FACT by poly(ADP-ribosyl)ation. Nucleic Acids Res 2006; 34:2398-407. [PMID: 16682447 PMCID: PMC1458519 DOI: 10.1093/nar/gkl241] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Chromatin-modifying factors play key roles in transcription, DNA replication and DNA repair. Post-translational modification of these proteins is largely responsible for regulating their activity. The FACT (facilitates chromatin transcription) complex, a heterodimer of hSpt16 and SSRP1, is a chromatin structure modulator whose involvement in transcription and DNA replication has been reported. Here we show that nucleosome binding activity of FACT complex is regulated by poly(ADP-ribosyl)ation. hSpt16, the large subunit of FACT, is poly(ADP-ribosyl)ated by poly(ADP-ribose) polymerase-1 (PARP-1) resulting from physical interaction between these two proteins. The level of hSpt16 poly(ADP-ribosyl)ation is elevated after genotoxic treatment and coincides with the activation of PARP-1. The enhanced hSpt16 poly(ADP-ribosyl)ation level correlates with the dissociation of FACT from chromatin in response to DNA damage. Our findings suggest that poly(ADP-ribosyl)ation of hSpt16 by PARP-1 play regulatory roles for FACT-mediated chromatin remodeling.
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Affiliation(s)
| | - Wei-Hao Chen
- Institute of Molecular Medicine, College of Medicine, National Taiwan UniversityTaipei, Taiwan
- Institute of Atomic and Molecular Sciences, Academia SinicaTaipei, Taiwan
| | | | | | | | - Sheng-Chung Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan UniversityTaipei, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Taiwan UniversityTaipei, Taiwan
- Institute of Biological Chemistry, Academia SinicaTaipei, Taiwan
- To whom correspondence should be addressed. Tel: 886 2 2312 3456, ext. 2982; Fax: 886 2 2321 0977;
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15
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Mu W, Han Q, Luo Z, Wang Y. Production of cis-syn thymine-thymine cyclobutane dimer oligonucleotide in the presence of acetone photosensitizer. Anal Biochem 2006; 353:117-23. [PMID: 16581009 DOI: 10.1016/j.ab.2006.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2006] [Revised: 02/18/2006] [Accepted: 03/03/2006] [Indexed: 11/17/2022]
Abstract
cis-syn Cyclobutane pyrimidine dimer (CPD) oligonucleotide was produced by UV irradiation in the presence of acetone photosensitizer. Acetone could enhance the productivity but evidently induced the photocleavage of oligonucleotide under a long time irradiation. A statistical approach of orthogonal design was applied to optimize the preparation condition for the production of the modified oligonucleotide. Optimal conditions for maximal cis-syn CPD oligonucleotide productivity were determined based on three factors: acetone concentration, initial oligonucleotide concentration, and irradiation time at several different levels. The optimal modified oligonucleotide that this optimization could produce was 32.7%. Through analysis of 20% polyacrylamide gel electrophoresis, it was found that modified oligonucleotide migrated slightly more slowly than the parent oligonucleotide. The photoreactivation of cis-syn thymine-thymine dimer oligonucleotide displayed the selectivity of the substrate specificity of DNA photolyase with high-performance liquid chromatography (HPLC) analysis.
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Affiliation(s)
- Wanmeng Mu
- School of Life Sciences, University of Science and Technology of China, Hefei
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16
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Rigo F, Kazerouninia A, Nag A, Martinson HG. The RNA tether from the poly(A) signal to the polymerase mediates coupling of transcription to cleavage and polyadenylation. Mol Cell 2006; 20:733-45. [PMID: 16337597 DOI: 10.1016/j.molcel.2005.09.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 09/15/2005] [Accepted: 09/30/2005] [Indexed: 11/15/2022]
Abstract
We have investigated the mechanism by which transcription accelerates cleavage and polyadenylation in vitro. By using a coupled transcription-processing system, we show that rapid and efficient 3' end processing occurs in the absence of crowding agents like polyvinyl alcohol. The continuity of the RNA from the poly(A) signal down to the polymerase is critical to this processing. If this tether is cut with DNA oligonucleotides and RNaseH during transcription, the efficiency of processing is drastically reduced. The polymerase is known to be an integral part of the cleavage and polyadenylation apparatus. RNA polymerase II pull-down and immobilized template experiments suggest that the role of the tether is to hold the poly(A) signal close to the polymerase during the early stages of processing complex assembly until the complex is sufficiently mature to remain stably associated with the polymerase on its own.
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Affiliation(s)
- Frank Rigo
- Department of Chemistry and Biochemistry and The Molecular Biology Institute, University of California, Los Angeles, 90095, USA
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17
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Conconi A, Paquette M, Fahy D, Bespalov VA, Smerdon MJ. Repair-independent chromatin assembly onto active ribosomal genes in yeast after UV irradiation. Mol Cell Biol 2005; 25:9773-83. [PMID: 16260595 PMCID: PMC1280247 DOI: 10.1128/mcb.25.22.9773-9783.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chromatin rearrangements occur during repair of cyclobutane pyrimidine dimers (CPDs) by nucleotide excision repair (NER). Thereafter, the original structure must be restored to retain normal genomic functions. How NER proceeds through nonnucleosomal chromatin and how open chromatin is reestablished after repair are unknown. We analyzed NER in ribosomal genes (rDNA), which are present in multiple copies but only a fraction are actively transcribed and nonnucleosomal. We show that removal of CPDs is fast in the active rDNA and that chromatin reorganization occurs during NER. Furthermore, chromatin assembles on nonnucleosomal rDNA during the early events of NER but in the absence of DNA repair. The resumption of transcription after removal of CPDs correlates with the reappearance of nonnucleosomal chromatin. To date, only the passage of replication machinery was thought to package ribosomal genes in nucleosomes. In this report, we show that early events after formation of UV photoproducts in DNA also promote chromatin assembly.
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Affiliation(s)
- Antonio Conconi
- Département de Microbiologie et d'Infectiologie, Faculté de Médecine, Poste 7446, Université de Sherbrooke, 3001 12th Ave. Nord, Sherbrooke, QC J1H 5N4, Canada.
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18
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Jung Y, Lippard SJ. RNA polymerase II blockage by cisplatin-damaged DNA. Stability and polyubiquitylation of stalled polymerase. J Biol Chem 2005; 281:1361-70. [PMID: 16275646 DOI: 10.1074/jbc.m509688200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The consequences of human RNA polymerase II (pol II) arrest at the site of DNA damaged by cisplatin were studied in whole cells and cell extracts, with a particular focus on the stability of stalled pol II and its subsequent ubiquitylation. Site-specifically platinated DNA templates immobilized on a solid support were used to perform in vitro transcription in HeLa nuclear extracts. RNA elongation was completely blocked by a cisplatin intrastrand cross-link. The stalled polymerase was quite stable, remaining on the DNA template in nuclear extracts. The stability of pol II stalled at the site of cisplatin damage was also observed in live cells. A cell fractionation experiment using cisplatin-treated HeLa cells revealed an increased level of chromatin-associated pol II proteins following DNA damage. The stalled polymerase was transcriptionally active and capable of elongating the transcript following chemical removal of platinum from the template. Transcription inhibition by alpha-amanitin in vitro enhanced pol II ubiquitylation at ubiquitin residues Lys-6, Lys-48, and Lys-63. In live cells expressing epitope-tagged ubiquitin mutants, several ubiquitin lysines also participated in pol II ubiquitylation following DNA damage. Cisplatin treatment triggered ubiquitylation-mediated pol II degradation in HeLa cells, which could be prevented by the proteasomal inhibitor MG132. Fractionation of pol II from cells co-treated with MG132 and cisplatin indicated that the undegraded ubiquitylated polymerase was mostly unbound or only loosely associated with chromatin. These data are consistent with a model in which only a fraction of pol II, ubiquitylated in response to cisplatin damage of DNA, dissociates from the sites of platination. This altered polymerase is rapidly destroyed by proteasomes.
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Affiliation(s)
- Yongwon Jung
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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19
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Zhang Z, Fu J, Gilmour DS. CTD-dependent dismantling of the RNA polymerase II elongation complex by the pre-mRNA 3'-end processing factor, Pcf11. Genes Dev 2005; 19:1572-80. [PMID: 15998810 PMCID: PMC1172063 DOI: 10.1101/gad.1296305] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Pcf11 is one of numerous proteins involved in pre-mRNA 3'-end processing and transcription termination. Using elongation complexes (ECs) formed from purified yeast RNA polymerase II (Pol II), we show that a 140-amino acid polypeptide from yeast Pcf11 is capable of dismantling the EC in vitro. This action depends on the C-terminal domain (CTD) of the largest subunit of Pol II and the CTD-interaction domain (CID) of Pcf11. Our experiments reveal a novel termination mechanism whereby Pcf11 bridges the CTD to the nascent transcript and causes dissociation of both Pol II and the nascent transcript from the DNA in the absence of nucleotide hydrolysis. We posit that conformational changes in the CTD are transduced through Pcf11 to the nascent transcript to cause termination.
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Affiliation(s)
- Zhiqiang Zhang
- Center for Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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20
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Abstract
Nucleotide-excision repair diseases exhibit cancer, complex developmental disorders and neurodegeneration. Cancer is the hallmark of xeroderma pigmentosum (XP), and neurodegeneration and developmental disorders are the hallmarks of Cockayne syndrome and trichothiodystrophy. A distinguishing feature is that the DNA-repair or DNA-replication deficiencies of XP involve most of the genome, whereas the defects in CS are confined to actively transcribed genes. Many of the proteins involved in repair are also components of dynamic multiprotein complexes, transcription factors, ubiquitylation cofactors and signal-transduction networks. Complex clinical phenotypes might therefore result from unanticipated effects on other genes and proteins.
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Affiliation(s)
- James E Cleaver
- Auerback Melanoma Laboratory, Room N431, UCSF Cancer Center, University of California, 94143-0808, USA.
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21
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Reardon JT, Sancar A. Nucleotide Excision Repair. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2005; 79:183-235. [PMID: 16096029 DOI: 10.1016/s0079-6603(04)79004-2] [Citation(s) in RCA: 223] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Joyce T Reardon
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA
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22
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Jiang Y, Liu M, Spencer CA, Price DH. Involvement of transcription termination factor 2 in mitotic repression of transcription elongation. Mol Cell 2004; 14:375-85. [PMID: 15125840 DOI: 10.1016/s1097-2765(04)00234-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2004] [Revised: 03/03/2004] [Accepted: 03/09/2004] [Indexed: 10/26/2022]
Abstract
All nuclear transcription is interrupted during mitosis. We examined the role of human TTF2, an RNA polymerase (Pol) I and II termination factor, in mitotic repression of transcription elongation. We find that TTF2 levels rise in the cytoplasm in S and G2 and at the onset of mitosis TTF2 translocates into the nucleus. Consistent with a role in termination of all transcription, TTF2 is the only ATP-dependent termination activity associated with Pol II transcription elongation complexes, is largely unaffected by template position, and is impervious to the phosphorylation state of the polymerase. Cells in which TTF2 levels are knocked down showed dramatic retention of Ser2 phosphorylated Pol II on mitotic chromosomes and an increase in chromosome segregation defects.
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Affiliation(s)
- Yan Jiang
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
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23
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Park NJ, Tsao DC, Martinson HG. The two steps of poly(A)-dependent termination, pausing and release, can be uncoupled by truncation of the RNA polymerase II carboxyl-terminal repeat domain. Mol Cell Biol 2004; 24:4092-103. [PMID: 15121832 PMCID: PMC400489 DOI: 10.1128/mcb.24.10.4092-4103.2004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The carboxyl-terminal repeat domain (CTD) of RNA polymerase II is thought to help coordinate events during RNA metabolism. The mammalian CTD consists of 52 imperfectly repeated heptads followed by 10 additional residues at the C terminus. The CTD is required for cleavage and polyadenylation in vitro. We studied poly(A)-dependent termination in vivo using CTD truncation mutants. Poly(A)-dependent termination occurs in two steps, pause and release. We found that the CTD is required for release, the first 25 heptads being sufficient. Neither the final 10 amino acids nor the variant heptads of the second half of the CTD were required. No part of the CTD was required for poly(A)-dependent pausing--the poly(A) signal could communicate directly with the body of the polymerase. By removing the CTD, pausing could be observed without being obscured by release. Poly(A)-dependent pausing appeared to operate by slowing down the polymerase, such as by down-regulation of a positive elongation factor. Although the first 25 heptads supported undiminished poly(A)-dependent termination, they did not efficiently support events near the promoter involved in abortive elongation. However, the second half of the CTD, including the final 10 amino acids, was sufficient for these functions.
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Affiliation(s)
- Noh Jin Park
- Department of Chemistry and Biochemistry and Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095-1569, USA
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24
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Roberts J, Park JS. Mfd, the bacterial transcription repair coupling factor: translocation, repair and termination. Curr Opin Microbiol 2004; 7:120-5. [PMID: 15063847 DOI: 10.1016/j.mib.2004.02.014] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mfd is a widely conserved bacterial protein that couples DNA repair with transcription. Mfd recognizes RNA polymerase stalled at a non-coding template site of DNA damage, disrupts the transcription complex to release the transcript and enzyme, and recruits the DNA excision repair machinery to the site. The mechanism of RNA release has been illuminated by the discovery that Mfd causes forward translocation of RNA polymerase, using an ATP-dependent motor that is highly homologous to that of the Holliday branch migration protein RecG.
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Affiliation(s)
- Jeffrey Roberts
- Department of Molecular Biology and Genetics, Biotechnology Building, Cornell University, Ithaca, NY 14853, USA.
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25
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Selby CP, Sancar A. Characterization of transcription-repair coupling factors in E. coli and humans. Methods Enzymol 2004; 371:300-24. [PMID: 14712710 DOI: 10.1016/s0076-6879(03)71023-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Affiliation(s)
- C P Selby
- Department of Biochemistry and Biophysics, University of North Carolina, School of Medicine, Chapel Hill, North Carolina 27599-7260, USA
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26
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Sancar A, Reardon JT. Nucleotide excision repair in E. coli and man. ADVANCES IN PROTEIN CHEMISTRY 2004; 69:43-71. [PMID: 15588839 DOI: 10.1016/s0065-3233(04)69002-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Aziz Sancar
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
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27
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Abstract
The human genome, comprising three billion base pairs coding for 30000-40000 genes, is constantly attacked by endogenous reactive metabolites, therapeutic drugs and a plethora of environmental mutagens that impact its integrity. Thus it is obvious that the stability of the genome must be under continuous surveillance. This is accomplished by DNA repair mechanisms, which have evolved to remove or to tolerate pre-cytotoxic, pre-mutagenic and pre-clastogenic DNA lesions in an error-free, or in some cases, error-prone way. Defects in DNA repair give rise to hypersensitivity to DNA-damaging agents, accumulation of mutations in the genome and finally to the development of cancer and various metabolic disorders. The importance of DNA repair is illustrated by DNA repair deficiency and genomic instability syndromes, which are characterised by increased cancer incidence and multiple metabolic alterations. Up to 130 genes have been identified in humans that are associated with DNA repair. This review is aimed at updating our current knowledge of the various repair pathways by providing an overview of DNA-repair genes and the corresponding proteins, participating either directly in DNA repair, or in checkpoint control and signaling of DNA damage.
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Affiliation(s)
- Markus Christmann
- Division of Applied Toxicology, Institute of Toxicology, University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany
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28
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Tremeau-Bravard A, Riedl T, Egly JM, Dahmus ME. Fate of RNA polymerase II stalled at a cisplatin lesion. J Biol Chem 2003; 279:7751-9. [PMID: 14672951 DOI: 10.1074/jbc.m309853200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Elongating RNA polymerase II blocked by DNA damage in the transcribed DNA strand is thought to initiate the transcription-coupled repair process. The objective of this study is to better understand the sequence of events that occurs during repair from the time RNA polymerase II first encounters the lesion. This study establishes that an immobilized DNA template containing a unique cisplatin lesion can serve as an in vitro substrate for both transcription and DNA repair. RNA polymerase II is quantitatively stalled at the cisplatin lesion during transcription and can be released from the template, along with the nascent transcript, in an ATP-dependent manner. RNA polymerase II stalled at a lesion and containing a dephosphorylated repetitive carboxyl-terminal domain (CTD) appears to be more sensitive toward release. However, a dephosphorylated CTD can become readily phosphorylated in front of the lesion by CTD kinases in the presence of ATP. The observation that RNA polymerase II and transcript release occurs in a TFIIH-deficient repair extract but not in a reconstituted repair system demonstrates that disassembly of the elongation complex can occur independently of the repair process and vice versa. Indeed, the presence of RNA polymerase II at the lesion does not prevent dual incision from occurring. Finally, we also propose that the Cockayne's syndrome B protein factor, believed to be the mammalian transcription repair coupling factor, is neither involved in transcript release nor required for dual incision in the presence of lesionstalled RNA polymerase II in vitro. More likely, it prevents RNA polymerase from backing up when it encounters the lesion. The ability to transcribe and repair the same damaged DNA molecule fixed on beads, along with the fact that the reaction conditions can be freely altered, provides a powerful tool to study the fate of RNA polymerase II blocked on the cisplatin lesion.
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29
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Licht CL, Stevnsner T, Bohr VA. Cockayne syndrome group B cellular and biochemical functions. Am J Hum Genet 2003; 73:1217-39. [PMID: 14639525 PMCID: PMC1180389 DOI: 10.1086/380399] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 10/01/2003] [Indexed: 01/17/2023] Open
Abstract
The devastating genetic disorder Cockayne syndrome (CS) arises from mutations in the CSA and CSB genes. CS is characterized by progressive multisystem degeneration and is classified as a segmental premature-aging syndrome. The CS complementation group B (CSB) protein is at the interface of transcription and DNA repair and is involved in transcription-coupled and global genome-DNA repair, as well as in general transcription. Recent structure-function studies indicate a process-dependent variation in the molecular mechanism employed by CSB and provide a starting ground for a description of the mechanisms and their interplay.
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Affiliation(s)
- Cecilie Löe Licht
- Laboratory of DNA Repair, Department of Molecular Biology, University of Aarhus, Aarhus, Denmark; and Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore
| | - Tinna Stevnsner
- Laboratory of DNA Repair, Department of Molecular Biology, University of Aarhus, Aarhus, Denmark; and Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore
| | - Vilhelm A. Bohr
- Laboratory of DNA Repair, Department of Molecular Biology, University of Aarhus, Aarhus, Denmark; and Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore
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30
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Jung Y, Lippard SJ. Multiple states of stalled T7 RNA polymerase at DNA lesions generated by platinum anticancer agents. J Biol Chem 2003; 278:52084-92. [PMID: 14534300 DOI: 10.1074/jbc.m310120200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Transcription inhibition by DNA adducts of cisplatin is considered to be one of the major routes by which this anticancer drug kills cancer cells. Stalled RNA polymerases at platinum-DNA lesions evoke various cellular responses such as nucleotide excision repair, polymerase degradation, and apoptosis. T7 RNA polymerase and site-specifically platinated DNA templates immobilized on a solid support were used to study stalled transcription elongation complexes. In vitro transcription studies were performed in both a promoter-dependent and -independent manner. An elongation complex is strongly blocked by cisplatin 1,2-intrastrand d(GpG) and 1,3-intrastrand d(GpTpG) cross-links located on the template strand. Polymerase action is inhibited at multiple sites in the vicinity of the platinum lesion, the nature of which can be altered by the choice and concentration of NTPs. The [(1R,2R-diaminocyclohexane)Pt]2+ DNA adducts formed by oxaliplatin, which carries a stereochemically more demanding spectator ligand than the ammine groups in cisplatin, also strongly block the polymerase with measurable differences compared with cis-[(NH3)2Pt]2+ lesions. Elongation complexes stopped at sites of platinum damage were isolated and characterized. The stalled polymerase can be dissociated from the DNA by subsequent polymerases initiated from the same template. We also discovered that a polymerase stalled at the platinum-DNA lesion can resume transcription after the platinum adduct is chemically removed from the template.
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Affiliation(s)
- Yongwon Jung
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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31
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Abstract
Long recognized as a target of regulation in prokaryotes, transcript elongation has recently become the focus of many investigators interested in eukaryotic gene expression. The growth of this area has been fueled by the availability of new methods and molecular structures, expanding sequence databases and an appreciation for the exquisite coordination required among different processes in the nucleus. Our article collates new information on regulatory accessory factors, as well as their ultimate target, RNA polymerase, in the nucleus of eukaryotic cells. How this regulation influences the biology of the organism is quite profound, and from single cell to multicellular eukaryotes significant similarities exist in the molecular responses to extracellular signals during transcript elongation. The most advanced genetic knowledge in this area comes from Saccharomyces cerevisiae, but the biochemistry and cell biology results from other organisms are also highlighted.
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Affiliation(s)
- Karen M Arndt
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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32
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Leonard D, Ajuh P, Lamond AI, Legerski RJ. hLodestar/HuF2 interacts with CDC5L and is involved in pre-mRNA splicing. Biochem Biophys Res Commun 2003; 308:793-801. [PMID: 12927788 DOI: 10.1016/s0006-291x(03)01486-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
hLodestar/HuF2 belongs to the SNF2 family of proteins. This family of proteins has been shown to play a critical role in altering protein-DNA interactions in a variety of cellular contexts. We have identified an unexpected interaction between hLodestar/HuF2 and CDC5L in both the yeast two-hybrid system and HeLa nuclear extract. CDC5L is a well-characterized pre-mRNA splicing factor in yeast and humans. Our findings demonstrate that hLodestar/HuF2 associates with human splicing complexes. We also found that a truncated hLodestar/HuF2 polypeptide that overlaps with the CDC5L-binding region can inhibit pre-mRNA splicing by disrupting spliceosome assembly. These findings indicate that hLodestar/HuF2 may have a role in pre-mRNA splicing. These data are consistent with a close co-ordination of the transcription and splicing pathways in eukaryotes. Although many members of the DExH/D helicase superfamily have been linked to pre-mRNA splicing, this is the first SNF2 family member to be implicated in this pathway.
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Affiliation(s)
- Deana Leonard
- Department of Molecular Genetics, M.D. Anderson Cancer Center, The University of Texas, Houston, TX 77030, USA
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33
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Facile synthesis of a cis–syn thymine dimer building block and its incorporation into oligodeoxynucleotides. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)01132-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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34
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Yu SL, Lee SK, Johnson RE, Prakash L, Prakash S. The stalling of transcription at abasic sites is highly mutagenic. Mol Cell Biol 2003; 23:382-8. [PMID: 12482989 PMCID: PMC140683 DOI: 10.1128/mcb.23.1.382-388.2003] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abasic (AP) sites represent one of the most frequently formed lesions in DNA. Here, we examine the consequences of the stalling of RNA polymerase II at AP sites in DNA in Saccharomyces cerevisiae. A severe inhibition of transcription occurs in strains that are defective in the removal of AP sites and that also lack the RAD26 gene, a homolog of the human Cockayne syndrome group B (CSB) gene, and, importantly, a dramatic rise in mutagenesis is incurred in such strains. From the various observations presented here, we infer that the stalling of transcription at AP sites is highly mutagenic.
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Affiliation(s)
- Sung-Lim Yu
- Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston 77555-1061, USA
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35
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Morland I, Rolseth V, Luna L, Rognes T, Bjørås M, Seeberg E. Human DNA glycosylases of the bacterial Fpg/MutM superfamily: an alternative pathway for the repair of 8-oxoguanine and other oxidation products in DNA. Nucleic Acids Res 2002; 30:4926-36. [PMID: 12433996 PMCID: PMC137166 DOI: 10.1093/nar/gkf618] [Citation(s) in RCA: 216] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The mild phenotype associated with targeted disruption of the mouse OGG1 and NTH1 genes has been attributed to the existence of back-up activities and/or alternative pathways for the removal of oxidised DNA bases. We have characterised two new genes in human cells that encode DNA glycosylases, homologous to the bacterial Fpg (MutM)/Nei class of enzymes, capable of removing lesions that are substrates for both hOGG1 and hNTH1. One gene, designated HFPG1, showed ubiquitous expression in all tissues examined whereas the second gene, HFPG2, was only expressed at detectable levels in the thymus and testis. Transient transfections of HeLa cells with fusions of the cDNAs to EGFP revealed intracellular sorting to the nucleus with accumulation in the nucleoli for hFPG1, while hFPG2 co-localised with the 30 kDa subunit of RPA. hFPG1 was purified and shown to act on DNA substrates containing 8-oxoguanine, 5-hydroxycytosine and abasic sites. Removal of 8-oxoguanine, but not cleavage at abasic sites, was opposite base-dependent, with 8-oxoG:C being the preferred substrate and negligible activity towards 8-oxoG:A. It thus appears that hFPG1 has properties similar to mammalian OGG1 in preventing mutations arising from misincorporation of A across 8-oxoG and could function as a back-up repair activity for OGG1 in ogg1(-/-) mice.
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Affiliation(s)
- Ingrid Morland
- Department of Molecular Biology, Institute of Medical Microbiology, University of Oslo, Rikshospitalet, 0027 Oslo, Norway
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36
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Hara R, Sancar A. The SWI/SNF chromatin-remodeling factor stimulates repair by human excision nuclease in the mononucleosome core particle. Mol Cell Biol 2002; 22:6779-87. [PMID: 12215535 PMCID: PMC134043 DOI: 10.1128/mcb.22.19.6779-6787.2002] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To investigate the role of chromatin remodeling in nucleotide excision repair, we prepared mononucleosomes with a 200-bp duplex containing an acetylaminofluorene-guanine (AAF-G) adduct at a single site. DNase I footprinting revealed a well-phased nucleosome structure with the AAF-G adduct near the center of twofold symmetry of the nucleosome core. This mononucleosome substrate was used to examine the effect of the SWI/SNF remodeling complex on the activity of human excision nuclease reconstituted from six purified excision repair factors. We found that the three repair factors implicated in damage recognition, RPA, XPA, and XPC, stimulate the remodeling activity of SWI/SNF, which in turn stimulates the removal of the AAF-G adduct from the nucleosome core by the excision nuclease. This is the first demonstration of the stimulation of nucleotide excision repair of a lesion in the nucleosome core by a chromatin-remodeling factor and contrasts with the ACF remodeling factor, which stimulates the removal of lesions from internucleosomal linker regions but not from the nucleosome core.
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Affiliation(s)
- Ryujiro Hara
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, 27599, USA
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37
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González-Barrera S, Prado F, Verhage R, Brouwer J, Aguilera A. Defective nucleotide excision repair in yeast hpr1 and tho2 mutants. Nucleic Acids Res 2002; 30:2193-201. [PMID: 12000839 PMCID: PMC115280 DOI: 10.1093/nar/30.10.2193] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Nucleotide excision repair (NER) and transcription are intimately related. First, TFIIH has a dual role in transcription initiation and NER and, secondly, transcription leads to more efficient repair of damage present in transcribed sequences. It is thought that elongating RNAPII, stalled at a DNA lesion, is used for the loading of the NER machinery in a process termed transcription-coupled repair (TCR). Non-transcribed regions are repaired by the so-called global genome repair (GGR). We have previously defined a number of yeast genes, whose deletions confer transcription-dependent hyper-recombination phenotypes. As these mutations cause impairment of transcription elongation we have assayed whether they also affect DNA repair. We show that null mutations of the HPR1 and THO2 genes, encoding two prominent proteins of the THO complex, increase UV sensitivity of yeast cells lacking GGR. Consistent with this result, molecular analyses of DNA repair of the RPB2 transcribed strand using T4 endo V show that hpr1 and tho2 do indeed impair TCR. However, this effect is not confined to TCR alone because the mutants are slightly affected in GGR. These results indicate that THO affects both transcription and NER. We discuss different alternatives to explain the effect of the THO complex on DNA repair.
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MESH Headings
- Blotting, Northern
- Cell Cycle Proteins
- DNA Repair/genetics
- DNA, Fungal/genetics
- DNA, Fungal/metabolism
- DNA, Fungal/radiation effects
- DNA-Binding Proteins
- Deoxyribonuclease (Pyrimidine Dimer)
- Dose-Response Relationship, Radiation
- Endodeoxyribonucleases/metabolism
- Fungal Proteins/genetics
- Gene Expression Regulation, Fungal/radiation effects
- Genotype
- Mating Factor
- Mutation
- Nuclear Proteins
- Peptides/genetics
- Protein Subunits
- RNA Polymerase II/genetics
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Fungal/radiation effects
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/radiation effects
- Saccharomyces cerevisiae Proteins
- Schizosaccharomyces pombe Proteins
- Transcription Factors/genetics
- Transcription, Genetic
- UDPglucose-Hexose-1-Phosphate Uridylyltransferase/genetics
- Ultraviolet Rays
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Affiliation(s)
- Sergio González-Barrera
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes 6, 41012 Sevilla, Spain
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38
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Meier A, Livingstone-Zatchej M, Thoma F. Repair of active and silenced rDNA in yeast: the contributions of photolyase and transcription-couples nucleotide excision repair. J Biol Chem 2002; 277:11845-52. [PMID: 11805105 DOI: 10.1074/jbc.m110941200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DNA repair by photolyase (photoreactivation) and nucleotide excision repair (NER) are the major pathways to remove UV-induced cyclobutane-pyrimidine dimers (CPDs). The nucleolus is a nuclear subcompartment containing the ribosomal RNA genes (rDNA) of which a fraction is transcribed by RNA polymerase I (RNAP-I), and the rest is silenced. Here yeast was used to investigate how photoreactivation and NER contribute to repair of active and inactive rDNA. Cells were irradiated with UV light and exposed to different repair conditions. Nuclei were isolated, and the active genes were separated from the inactive genes by restriction endonuclease digestion. CPDs were measured in total rDNA, in both fractions, and in the GAL10 gene. Repair in rDNA was as efficient as in GAL10 indicating that both pathways have unrestricted access to the nucleolus. Photoreactivation was much faster than NER and therefore was the predominant repair pathway. Active genes were faster repaired by photolyase than were silenced genes providing evidence for an open chromatin structure during repair. The transcribed strands of active genes, but not of inactive genes, were slightly faster repaired by NER providing evidence for transcription-coupled repair by RNAP-I. There was no pronounced inhibition of photoreactivation by RNAP-I in the transcribed strand, which is in contrast to genes transcribed by RNAP-II and suggests different stabilities of RNAP-I and RNAP-II stalled at CPDs.
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Affiliation(s)
- Andreas Meier
- Institut für Zellbiologie, Departement Biologie, Eidgenössische Technische Hochschule (ETH), Hönggerberg, CH-8093 Zürich, Switzerland
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39
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Abstract
Several types of helix-distorting DNA lesions block the passage of elongating RNA polymerase II. Surprisingly, such transcription-blocking lesions are usually repaired considerably faster than non-obstructive lesions in the non-transcribed strand or in the genome overall. In this review, our knowledge of eukaryotic transcription-coupled repair (TCR) will be considered from the point of view of transcription, and current models for the mechanism of TCR will be discussed.
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Affiliation(s)
- Jesper Q Svejstrup
- Imperial Cancer Research Fund, Clare Hall Laboratories, Blanche Lane, South Mimms, Hertfordshire EN6 3LD, UK.
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40
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Chao SH, Greenleaf AL, Price DH. Juglone, an inhibitor of the peptidyl-prolyl isomerase Pin1, also directly blocks transcription. Nucleic Acids Res 2001; 29:767-73. [PMID: 11160900 PMCID: PMC30403 DOI: 10.1093/nar/29.3.767] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The C-terminal domain (CTD) of the large subunit of RNA polymerase II plays a role in transcription and RNA processing. Yeast ESS1, a peptidyl-prolyl cis/trans isomerase, is involved in RNA processing and can associate with the CTD. Using several types of assays we could not find any evidence of an effect of Pin1, the human homolog of ESS1, on transcription by RNA polymerase II in vitro or on the expression of a reporter gene in vivo. However, an inhibitor of Pin1, 5-hydroxy-1,4-naphthoquinone (juglone), blocked transcription by RNA polymerase II. Unlike N-ethylmaleimide, which inhibited all phases of transcription by RNA polymerase II, juglone disrupted the formation of functional preinitiation complexes by modifying sulfhydryl groups but did not have any significant effect on either initiation or elongation. Both RNA polymerases I and III, but not T7 RNA polymerase, were inhibited by juglone. The primary target of juglone has not been unambiguously identified, although a site on the polymerase itself is suggested by inhibition of RNA polymerase II during factor-independent transcription of single-stranded DNA. Because of its unique inhibitory properties juglone should prove useful in studying transcription in vitro.
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Affiliation(s)
- S H Chao
- Molecular Biology Program, University of Iowa, Iowa City, IA 52242, USA
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