1
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Li H, Ding Z, Fang ZY, Long N, Ang HY, Zhang Y, Fan YJ, Xu YZ. Conserved intronic secondary structures with concealed branch sites regulate alternative splicing of poison exons. Nucleic Acids Res 2024; 52:6002-6016. [PMID: 38499485 PMCID: PMC11162794 DOI: 10.1093/nar/gkae185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 02/23/2024] [Accepted: 03/05/2024] [Indexed: 03/20/2024] Open
Abstract
Alternative splicing (AS) generates multiple RNA isoforms and increases the complexities of transcriptomes and proteomes. However, it remains unclear how RNA structures contribute to AS regulation. Here, we systematically search transcriptomes for secondary structures with concealed branch sites (BSs) in the alternatively spliced introns and predict thousands of them from six organisms, of which many are evolutionarily conserved. Intriguingly, a highly conserved stem-loop structure with concealed BSs is found in animal SF3B3 genes and colocalizes with a downstream poison exon (PE). Destabilization of this structure allows increased usage of the BSs and results in enhanced PE inclusion in human and Drosophila cells, leading to decreased expression of SF3B3. This structure is experimentally validated using an in-cell SHAPE-MaP assay. Through RNA interference screens of 28 RNA-binding proteins, we find that this stem-loop structure is sensitive to U2 factors. Furthermore, we find that SF3B3 also facilitates DNA repair and protects genome stability by enhancing interaction between ERCC6/CSB and arrested RNA polymerase II. Importantly, both Drosophila and human cells with the secondary structure mutated by genome editing exhibit altered DNA repair in vivo. This study provides a novel and common mechanism for AS regulation of PEs and reveals a physiological function of SF3B3 in DNA repair.
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Affiliation(s)
- Hao Li
- RNA Institute, State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Hubei 430072, China
| | - Zhan Ding
- RNA Institute, State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Hubei 430072, China
| | - Zhuo-Ya Fang
- RNA Institute, State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Hubei 430072, China
| | - Ni Long
- RNA Institute, State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Hubei 430072, China
| | - Hao-Yang Ang
- RNA Institute, State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Hubei 430072, China
| | - Yu Zhang
- Genome Institute of Singapore, Agency for Science, Technology and Research (A*STAR), Singapore, 138672, Singapore
| | - Yu-Jie Fan
- RNA Institute, State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Hubei 430072, China
| | - Yong-Zhen Xu
- RNA Institute, State Key Laboratory of Virology, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan University, Hubei 430072, China
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2
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Morledge-Hampton B, Kalyanaraman A, Wyrick JJ. Analysis of cytosine deamination events in excision repair sequencing reads reveals mechanisms of incision site selection in NER. Nucleic Acids Res 2024; 52:1720-1735. [PMID: 38109317 PMCID: PMC10899786 DOI: 10.1093/nar/gkad1195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 12/20/2023] Open
Abstract
Nucleotide excision repair (NER) removes helix-distorting DNA lesions and is therefore critical for genome stability. During NER, DNA is unwound on either side of the lesion and excised, but the rules governing incision site selection, particularly in eukaryotic cells, are unclear. Excision repair-sequencing (XR-seq) sequences excised NER fragments, but analysis has been limited because the lesion location is unknown. Here, we exploit accelerated cytosine deamination rates in UV-induced CPD (cyclobutane pyrimidine dimer) lesions to precisely map their locations at C to T mismatches in XR-seq reads, revealing general and species-specific patterns of incision site selection during NER. Our data indicate that the 5' incision site occurs preferentially in HYV (i.e. not G; C/T; not T) sequence motifs, a pattern that can be explained by sequence preferences of the XPF-ERCC1 endonuclease. In contrast, the 3' incision site does not show strong sequence preferences, once truncated reads arising from mispriming events are excluded. Instead, the 3' incision is partially determined by the 5' incision site distance, indicating that the two incision events are coupled. Finally, our data reveal unique and coupled NER incision patterns at nucleosome boundaries. These findings reveal key principles governing NER incision site selection in eukaryotic cells.
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Affiliation(s)
| | - Ananth Kalyanaraman
- School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99164, USA
| | - John J Wyrick
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA
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3
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van der Woude M, Davó-Martínez C, Thijssen K, Vermeulen W, Lans H. Recovery of protein synthesis to assay DNA repair activity in transcribed genes in living cells and tissues. Nucleic Acids Res 2023; 51:e93. [PMID: 37522336 PMCID: PMC10570043 DOI: 10.1093/nar/gkad642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 06/19/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023] Open
Abstract
Transcription-coupled nucleotide excision repair (TC-NER) is an important DNA repair mechanism that protects against the negative effects of transcription-blocking DNA lesions. Hereditary TC-NER deficiencies cause pleiotropic and often severe neurodegenerative and progeroid symptoms. While multiple assays have been developed to determine TC-NER activity for clinical and research purposes, monitoring TC-NER is hampered by the low frequency of repair events occurring in transcribed DNA. 'Recovery of RNA Synthesis' is widely used as indirect TC-NER assay based on the notion that lesion-blocked transcription only resumes after successful TC-NER. Here, we show that measuring novel synthesis of a protein after its compound-induced degradation prior to DNA damage induction is an equally effective but more versatile manner to indirectly monitor DNA repair activity in transcribed genes. This 'Recovery of Protein Synthesis' (RPS) assay can be adapted to various degradable proteins and readouts, including imaging and immunoblotting. Moreover, RPS allows real-time monitoring of TC-NER activity in various living cells types and even in differentiated tissues of living organisms. To illustrate its utility, we show that DNA repair in transcribed genes declines in aging muscle tissue of C. elegans. Therefore, the RPS assay constitutes an important novel clinical and research tool to investigate transcription-coupled DNA repair.
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Affiliation(s)
- Melanie van der Woude
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Carlota Davó-Martínez
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Karen L Thijssen
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Wim Vermeulen
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Hannes Lans
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
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4
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Wang J, Muste Sadurni M, Saponaro M. RNAPII response to transcription-blocking DNA lesions in mammalian cells. FEBS J 2023; 290:4382-4394. [PMID: 35731652 PMCID: PMC10952651 DOI: 10.1111/febs.16561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 05/15/2022] [Accepted: 06/21/2022] [Indexed: 09/21/2023]
Abstract
RNA polymerase II moves along genes to decode genetic information stored in the mammalian genome into messenger RNA and different forms of non-coding RNA. However, the transcription process is frequently challenged by DNA lesions caused by exogenous and endogenous insults, among which helix-distorting DNA lesions and double-stranded DNA breaks are particularly harmful for cell survival. In response to such DNA damage, RNA polymerase II transcription is regulated both locally and globally by multi-layer mechanisms, whereas transcription-blocking lesions are repaired before transcription can recover. Failure in DNA damage repair will cause genome instability and cell death. Although recent studies have expanded our understanding of RNA polymerase II regulation confronting DNA lesions, it is still not always clear what the direct contribution of RNA polymerase II is in the DNA damage repair processes. In this review, we focus on how RNA polymerase II and transcription are both repressed by transcription stalling lesions such as DNA-adducts and double strand breaks, as well as how they are actively regulated to support the cellular response to DNA damage and favour the repair of lesions.
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Affiliation(s)
- Jianming Wang
- Transcription Associated Genome Instability Laboratory, Institute of Cancer and Genomic SciencesUniversity of BirminghamUK
| | - Martina Muste Sadurni
- Transcription Associated Genome Instability Laboratory, Institute of Cancer and Genomic SciencesUniversity of BirminghamUK
| | - Marco Saponaro
- Transcription Associated Genome Instability Laboratory, Institute of Cancer and Genomic SciencesUniversity of BirminghamUK
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5
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Song A, Chen FX. The pleiotropic roles of SPT5 in transcription. Transcription 2022; 13:53-69. [PMID: 35876486 PMCID: PMC9467590 DOI: 10.1080/21541264.2022.2103366] [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] [Indexed: 10/25/2022] Open
Abstract
Initially discovered by genetic screens in budding yeast, SPT5 and its partner SPT4 form a stable complex known as DSIF in metazoa, which plays pleiotropic roles in multiple steps of transcription. SPT5 is the most conserved transcription elongation factor, being found in all three domains of life; however, its structure has evolved to include new domains and associated posttranslational modifications. These gained features have expanded transcriptional functions of SPT5, likely to meet the demand for increasingly complex regulation of transcription in higher organisms. This review discusses the pleiotropic roles of SPT5 in transcription, including RNA polymerase II (Pol II) stabilization, enhancer activation, Pol II pausing and its release, elongation, and termination, with a focus on the most recent progress of SPT5 functions in regulating metazoan transcription.
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Affiliation(s)
- Aixia Song
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
| | - Fei Xavier Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
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6
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Zhang X, Yin M, Hu J. Nucleotide excision repair: a versatile and smart toolkit. Acta Biochim Biophys Sin (Shanghai) 2022; 54:807-819. [PMID: 35975604 PMCID: PMC9828404 DOI: 10.3724/abbs.2022054] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Nucleotide excision repair (NER) is a major pathway to deal with bulky adducts induced by various environmental toxins in all cellular organisms. The two sub-pathways of NER, global genome repair (GGR) and transcription-coupled repair (TCR), differ in the damage recognition modes. In this review, we describe the molecular mechanism of NER in mammalian cells, especially the details of damage recognition steps in both sub-pathways. We also introduce new sequencing methods for genome-wide mapping of NER, as well as recent advances about NER in chromatin by these methods. Finally, the roles of NER factors in repairing oxidative damages and resolving R-loops are discussed.
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Affiliation(s)
| | | | - Jinchuan Hu
- Correspondence address. Tel: +86-21-54237702; E-mail:
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7
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Liano D, Chowdhury S, Di Antonio M. Cockayne Syndrome B Protein Selectively Resolves and Interact with Intermolecular DNA G-Quadruplex Structures. J Am Chem Soc 2021; 143:20988-21002. [PMID: 34855372 DOI: 10.1021/jacs.1c10745] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Guanine-rich DNA can fold into secondary structures known as G-quadruplexes (G4s). G4s can form from a single DNA strand (intramolecular) or from multiple DNA strands (intermolecular), but studies on their biological functions have been often limited to intramolecular G4s, owing to the low probability of intermolecular G4s to form within genomic DNA. Herein, we report the first example of an endogenous protein, Cockayne Syndrome B (CSB), that can bind selectively with picomolar affinity toward intermolecular G4s formed within rDNA while displaying negligible binding toward intramolecular structures. We observed that CSB can selectively resolve intermolecular over intramolecular G4s, demonstrating that its selectivity toward intermolecular structures is also reflected at the resolvase level. Immunostaining of G4s with the antibody BG4 in CSB-impaired cells (CS1AN) revealed that G4-staining in the nucleolus of these cells can be abrogated by transfection of viable CSB, suggesting that intermolecular G4s can be formed within rDNA and act as binding substrate for CSB. Given that loss of function of CSB elicits premature aging phenotypes, our findings indicate that the interaction between CSB and intermolecular G4s in rDNA could be of relevance to maintain cellular homeostasis.
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Affiliation(s)
- Denise Liano
- Chemistry Department, Imperial College London, Molecular Science Research Hub, 82 Wood Lane, London W12 0BZ, United Kingdom.,Institute of Chemical Biology, Molecular Science Research Hub, 82 Wood Lane, London W12 0BZ, United Kingdom
| | - Souroprobho Chowdhury
- Chemistry Department, Imperial College London, Molecular Science Research Hub, 82 Wood Lane, London W12 0BZ, United Kingdom.,Institute of Chemical Biology, Molecular Science Research Hub, 82 Wood Lane, London W12 0BZ, United Kingdom
| | - Marco Di Antonio
- Chemistry Department, Imperial College London, Molecular Science Research Hub, 82 Wood Lane, London W12 0BZ, United Kingdom.,Institute of Chemical Biology, Molecular Science Research Hub, 82 Wood Lane, London W12 0BZ, United Kingdom.,The Francis Crick Institute, London, NW1 1AT, United Kingdom
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8
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Lanzafame M, Branca G, Landi C, Qiang M, Vaz B, Nardo T, Ferri D, Mura M, Iben S, Stefanini M, Peverali FA, Bini L, Orioli D. Cockayne syndrome group A and ferrochelatase finely tune ribosomal gene transcription and its response to UV irradiation. Nucleic Acids Res 2021; 49:10911-10930. [PMID: 34581821 PMCID: PMC8565352 DOI: 10.1093/nar/gkab819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 08/10/2021] [Accepted: 09/12/2021] [Indexed: 11/14/2022] Open
Abstract
CSA and CSB proteins are key players in transcription-coupled nucleotide excision repair (TC-NER) pathway that removes UV-induced DNA lesions from the transcribed strands of expressed genes. Additionally, CS proteins play relevant but still elusive roles in other cellular pathways whose alteration may explain neurodegeneration and progeroid features in Cockayne syndrome (CS). Here we identify a CS-containing chromatin-associated protein complex that modulates rRNA transcription. Besides RNA polymerase I (RNAP1) and specific ribosomal proteins (RPs), the complex includes ferrochelatase (FECH), a well-known mitochondrial enzyme whose deficiency causes erythropoietic protoporphyria (EPP). Impairment of either CSA or FECH functionality leads to reduced RNAP1 occupancy on rDNA promoter that is associated to reduced 47S pre-rRNA transcription. In addition, reduced FECH expression leads to an abnormal accumulation of 18S rRNA that in primary dermal fibroblasts from CS and EPP patients results in opposed rRNA amounts. After cell irradiation with UV light, CSA triggers the dissociation of the CSA–FECH–CSB–RNAP1–RPs complex from the chromatin while it stabilizes its binding to FECH. Besides disclosing a function for FECH within nucleoli, this study sheds light on the still unknown mechanisms through which CSA modulates rRNA transcription.
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Affiliation(s)
- Manuela Lanzafame
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Giulia Branca
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Claudia Landi
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Mingyue Qiang
- Department of Dermatology and Allergic Diseases, Ulm University, Albert-Einstein Allee 23, 89081 Ulm, Germany
| | - Bruno Vaz
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Tiziana Nardo
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Debora Ferri
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Manuela Mura
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Sebastian Iben
- Department of Dermatology and Allergic Diseases, Ulm University, Albert-Einstein Allee 23, 89081 Ulm, Germany
| | - Miria Stefanini
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Fiorenzo A Peverali
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
| | - Luca Bini
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Donata Orioli
- Institute of Molecular Genetics -L.L. Cavalli Sforza, CNR, 27100 Pavia, Italy
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9
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Fleming AM, Burrows CJ. Oxidative stress-mediated epigenetic regulation by G-quadruplexes. NAR Cancer 2021; 3:zcab038. [PMID: 34541539 PMCID: PMC8445369 DOI: 10.1093/narcan/zcab038] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/20/2021] [Accepted: 09/06/2021] [Indexed: 02/06/2023] Open
Abstract
Many cancer-associated genes are regulated by guanine (G)-rich sequences that are capable of refolding from the canonical duplex structure to an intrastrand G-quadruplex. These same sequences are sensitive to oxidative damage that is repaired by the base excision repair glycosylases OGG1 and NEIL1–3. We describe studies indicating that oxidation of a guanosine base in a gene promoter G-quadruplex can lead to up- and downregulation of gene expression that is location dependent and involves the base excision repair pathway in which the first intermediate, an apurinic (AP) site, plays a key role mediated by AP endonuclease 1 (APE1/REF1). The nuclease activity of APE1 is paused at a G-quadruplex, while the REF1 capacity of this protein engages activating transcription factors such as HIF-1α, AP-1 and p53. The mechanism has been probed by in vitro biophysical studies, whole-genome approaches and reporter plasmids in cellulo. Replacement of promoter elements by a G-quadruplex sequence usually led to upregulation, but depending on the strand and precise location, examples of downregulation were also found. The impact of oxidative stress-mediated lesions in the G-rich sequence enhanced the effect, whether it was positive or negative.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry, University of Utah, 315 S. 1400 East, Salt Lake City, UT 84112-0850, USA
| | - Cynthia J Burrows
- Department of Chemistry, University of Utah, 315 S. 1400 East, Salt Lake City, UT 84112-0850, USA
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10
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Abstract
Transcription-coupled DNA repair removes bulky DNA lesions from the genome1,2 and protects cells against ultraviolet (UV) irradiation3. Transcription-coupled DNA repair begins when RNA polymerase II (Pol II) stalls at a DNA lesion and recruits the Cockayne syndrome protein CSB, the E3 ubiquitin ligase, CRL4CSA and UV-stimulated scaffold protein A (UVSSA)3. Here we provide five high-resolution structures of Pol II transcription complexes containing human transcription-coupled DNA repair factors and the elongation factors PAF1 complex (PAF) and SPT6. Together with biochemical and published3,4 data, the structures provide a model for transcription–repair coupling. Stalling of Pol II at a DNA lesion triggers replacement of the elongation factor DSIF by CSB, which binds to PAF and moves upstream DNA to SPT6. The resulting elongation complex, ECTCR, uses the CSA-stimulated translocase activity of CSB to pull on upstream DNA and push Pol II forward. If the lesion cannot be bypassed, CRL4CSA spans over the Pol II clamp and ubiquitylates the RPB1 residue K1268, enabling recruitment of TFIIH to UVSSA and DNA repair. Conformational changes in CRL4CSA lead to ubiquitylation of CSB and to release of transcription-coupled DNA repair factors before transcription may continue over repaired DNA. The authors resolve the structure of five complexes containing RNA polymerase II and the CSA and CSB proteins, offering insight into how the repair of DNA lesions is coupled to transcription.
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11
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Datta A, Pollock KJ, Kormuth KA, Brosh RM. G-Quadruplex Assembly by Ribosomal DNA: Emerging Roles in Disease Pathogenesis and Cancer Biology. Cytogenet Genome Res 2021; 161:285-296. [PMID: 34469893 DOI: 10.1159/000516394] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/03/2021] [Indexed: 12/15/2022] Open
Abstract
Unique repetitive elements of the eukaryotic genome can be problematic for cellular DNA replication and transcription and pose a source of genomic instability. Human ribosomal DNA (rDNA) exists as repeating units clustered together on several chromosomes. Understanding the molecular mechanisms whereby rDNA interferes with normal genome homeostasis is the subject of this review. We discuss the instability of rDNA as a driver of senescence and the important roles of helicases to suppress its deleterious effects. The propensity of rDNA that is rich in guanine bases to form G-quadruplexes (G4) is discussed and evaluated in disease pathogenesis. Targeting G4 in the ribosomes and other chromosomal loci may represent a useful synthetic lethal approach to combating cancer.
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Affiliation(s)
- Arindam Datta
- Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, Maryland, USA
| | - Kevin J Pollock
- Department of Biology, Bethany College, Bethany, West Virginia, USA
| | - Karen A Kormuth
- Department of Biology, Bethany College, Bethany, West Virginia, USA
| | - Robert M Brosh
- Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, Maryland, USA
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12
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Gaul L, Svejstrup JQ. Transcription-coupled repair and the transcriptional response to UV-Irradiation. DNA Repair (Amst) 2021; 107:103208. [PMID: 34416541 DOI: 10.1016/j.dnarep.2021.103208] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 02/07/2023]
Abstract
Lesions in genes that result in RNA polymerase II (RNAPII) stalling or arrest are particularly toxic as they are a focal point of genome instability and potently block further transcription of the affected gene. Thus, cells have evolved the transcription-coupled nucleotide excision repair (TC-NER) pathway to identify damage-stalled RNAPIIs, so that the lesion can be rapidly repaired and transcription can continue. However, despite the identification of several factors required for TC-NER, how RNAPII is remodelled, modified, removed, or whether this is even necessary for repair remains enigmatic, and theories are intensely contested. Recent studies have further detailed the cellular response to UV-induced ubiquitylation and degradation of RNAPII and its consequences for transcription and repair. These advances make it pertinent to revisit the TC-NER process in general and with specific discussion of the fate of RNAPII stalled at DNA lesions.
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Affiliation(s)
- Liam Gaul
- Department of Cellular and Molecular Medicine, Panum Institute, Blegdamsvej 3B, University of Copenhagen, 2200, Copenhagen N, Denmark
| | - Jesper Q Svejstrup
- Department of Cellular and Molecular Medicine, Panum Institute, Blegdamsvej 3B, University of Copenhagen, 2200, Copenhagen N, Denmark.
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13
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Jia N, Guo C, Nakazawa Y, van den Heuvel D, Luijsterburg MS, Ogi T. Dealing with transcription-blocking DNA damage: Repair mechanisms, RNA polymerase II processing and human disorders. DNA Repair (Amst) 2021; 106:103192. [PMID: 34358806 DOI: 10.1016/j.dnarep.2021.103192] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/23/2021] [Accepted: 07/25/2021] [Indexed: 12/15/2022]
Abstract
Transcription-blocking DNA lesions (TBLs) in genomic DNA are triggered by a wide variety of DNA-damaging agents. Such lesions cause stalling of elongating RNA polymerase II (RNA Pol II) enzymes and fully block transcription when unresolved. The toxic impact of DNA damage on transcription progression is commonly referred to as transcription stress. In response to RNA Pol II stalling, cells activate and employ transcription-coupled repair (TCR) machineries to repair cytotoxic TBLs and resume transcription. Increasing evidence indicates that the modification and processing of stalled RNA Pol II is an integral component of the cellular response to and the repair of TBLs. If TCR pathways fail, the prolonged stalling of RNA Pol II will impede global replication and transcription as well as block the access of other DNA repair pathways that may act upon the TBL. Consequently, such prolonged stalling will trigger profound genome instability and devastating clinical features. In this review, we will discuss the mechanisms by which various types of TBLs are repaired by distinct TCR pathways and how RNA Pol II processing is regulated during these processes. We will also discuss the clinical consequences of transcription stress and genotype-phenotype correlations of related TCR-deficiency disorders.
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Affiliation(s)
- Nan Jia
- Department of Allergy and Clinical Immunology, National Clinical Research Center for Respiratory Disease, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China; Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Nagoya, Japan; Department of Human Genetics and Molecular Biology, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Chaowan Guo
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Nagoya, Japan; Department of Human Genetics and Molecular Biology, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Yuka Nakazawa
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Nagoya, Japan; Department of Human Genetics and Molecular Biology, Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Diana van den Heuvel
- Department of Human Genetics, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Martijn S Luijsterburg
- Department of Human Genetics, Leiden University Medical Center (LUMC), Leiden, The Netherlands.
| | - Tomoo Ogi
- Department of Genetics, Research Institute of Environmental Medicine (RIeM), Nagoya University, Nagoya, Japan; Department of Human Genetics and Molecular Biology, Graduate School of Medicine, Nagoya University, Nagoya, Japan.
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14
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D'Errico M, Parlanti E, Pascucci B, Filomeni G, Mastroberardino PG, Dogliotti E. The interplay between mitochondrial functionality and genome integrity in the prevention of human neurologic diseases. Arch Biochem Biophys 2021; 710:108977. [PMID: 34174223 DOI: 10.1016/j.abb.2021.108977] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 12/23/2022]
Abstract
As mitochondria are vulnerable to oxidative damage and represent the main source of reactive oxygen species (ROS), they are considered key tuners of ROS metabolism and buffering, whose dysfunction can progressively impact neuronal networks and disease. Defects in DNA repair and DNA damage response (DDR) may also affect neuronal health and lead to neuropathology. A number of congenital DNA repair and DDR defective syndromes, indeed, show neurological phenotypes, and a growing body of evidence indicate that defects in the mechanisms that control genome stability in neurons acts as aging-related modifiers of common neurodegenerative diseases such as Alzheimer, Parkinson's, Huntington diseases and Amyotrophic Lateral Sclerosis. In this review we elaborate on the established principles and recent concepts supporting the hypothesis that deficiencies in either DNA repair or DDR might contribute to neurodegeneration via mechanisms involving mitochondrial dysfunction/deranged metabolism.
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Affiliation(s)
| | - Eleonora Parlanti
- Department of Environment and Health, Istituto Superiore di Sanità, Rome, Italy
| | - Barbara Pascucci
- Institute of Crystallography, Consiglio Nazionale Delle Ricerche, Rome, Italy
| | - Giuseppe Filomeni
- Redox Biology, Danish Cancer Society Research Center, Copenhagen, Denmark; Center for Healthy Aging, Copenhagen University, Copenhagen, Denmark; Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Pier Giorgio Mastroberardino
- Department of Molecular Genetics, Erasmus MC, Rotterdam, the Netherlands; IFOM- FIRC Institute of Molecular Oncology, Milan, Italy; Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Eugenia Dogliotti
- Department of Environment and Health, Istituto Superiore di Sanità, Rome, Italy.
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15
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Chauhan AK, Sun Y, Zhu Q, Wani AA. Timely upstream events regulating nucleotide excision repair by ubiquitin-proteasome system: ubiquitin guides the way. DNA Repair (Amst) 2021; 103:103128. [PMID: 33991872 DOI: 10.1016/j.dnarep.2021.103128] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/15/2021] [Accepted: 05/04/2021] [Indexed: 12/11/2022]
Abstract
The ubiquitin-proteasome system (UPS) plays crucial roles in regulation of multiple DNA repair pathways, including nucleotide excision repair (NER), which eliminates a broad variety of helix-distorting DNA lesions that can otherwise cause deleterious mutations and genomic instability. In mammalian NER, DNA damage sensors, DDB and XPC acting in global genomic NER (GG-NER), and, CSB and RNAPII acting in transcription-coupled NER (TC-NER) sub-pathways, undergo an array of post-translational ubiquitination at the DNA lesion sites. Accumulating evidence indicates that ubiquitination orchestrates the productive assembly of NER preincision complex by driving well-timed compositional changes in DNA damage-assembled sensor complexes. Conversely, the deubiquitination is also intimately involved in regulating the damage sensing aftermath, via removal of degradative ubiquitin modification on XPC and CSB to prevent their proteolysis for the factor recycling. This review summaries the relevant research efforts and latest findings in our understanding of ubiquitin-mediated regulation of NER and active participation by new regulators of NER, e.g., Cullin-Ring ubiquitin ligases (CRLs), ubiquitin-specific proteases (USPs) and ubiquitin-dependent segregase, valosin-containing protein (VCP)/p97. We project hypothetical step-by-step models in which VCP/p97-mediated timely extraction of damage sensors is integral to overall productive NER. The USPs and proteasome subtly counteract in fine-tuning the vital stability and function of NER damage sensors.
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Affiliation(s)
- Anil K Chauhan
- Department of Radiology, The Ohio State University, Columbus, OH, 43210, United States
| | - Yingming Sun
- Department of Radiology, The Ohio State University, Columbus, OH, 43210, United States
| | - Qianzheng Zhu
- Department of Radiology, The Ohio State University, Columbus, OH, 43210, United States.
| | - Altaf A Wani
- Department of Radiology, The Ohio State University, Columbus, OH, 43210, United States; Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH, 43210, United States; James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH, 43210, United States.
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16
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Tiwari V, Baptiste BA, Okur MN, Bohr VA. Current and emerging roles of Cockayne syndrome group B (CSB) protein. Nucleic Acids Res 2021; 49:2418-2434. [PMID: 33590097 DOI: 10.1093/nar/gkab085] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/26/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
Cockayne syndrome (CS) is a segmental premature aging syndrome caused primarily by defects in the CSA or CSB genes. In addition to premature aging, CS patients typically exhibit microcephaly, progressive mental and sensorial retardation and cutaneous photosensitivity. Defects in the CSB gene were initially thought to primarily impair transcription-coupled nucleotide excision repair (TC-NER), predicting a relatively consistent phenotype among CS patients. In contrast, the phenotypes of CS patients are pleiotropic and variable. The latter is consistent with recent work that implicates CSB in multiple cellular systems and pathways, including DNA base excision repair, interstrand cross-link repair, transcription, chromatin remodeling, RNAPII processing, nucleolin regulation, rDNA transcription, redox homeostasis, and mitochondrial function. The discovery of additional functions for CSB could potentially explain the many clinical phenotypes of CSB patients. This review focuses on the diverse roles played by CSB in cellular pathways that enhance genome stability, providing insight into the molecular features of this complex premature aging disease.
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Affiliation(s)
- Vinod Tiwari
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Beverly A Baptiste
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Mustafa N Okur
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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17
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Batenburg NL, Cui S, Walker JR, Schellhorn HE, Zhu XD. The Winged Helix Domain of CSB Regulates RNAPII Occupancy at Promoter Proximal Pause Sites. Int J Mol Sci 2021; 22:ijms22073379. [PMID: 33806087 PMCID: PMC8037043 DOI: 10.3390/ijms22073379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/19/2021] [Accepted: 03/24/2021] [Indexed: 12/16/2022] Open
Abstract
Cockayne syndrome group B protein (CSB), a member of the SWI/SNF superfamily, resides in an elongating RNA polymerase II (RNAPII) complex and regulates transcription elongation. CSB contains a C-terminal winged helix domain (WHD) that binds to ubiquitin and plays an important role in DNA repair. However, little is known about the role of the CSB-WHD in transcription regulation. Here, we report that CSB is dependent upon its WHD to regulate RNAPII abundance at promoter proximal pause (PPP) sites of several actively transcribed genes, a key step in the regulation of transcription elongation. We show that two ubiquitin binding-defective mutations in the CSB-WHD, which impair CSB's ability to promote cell survival in response to treatment with cisplatin, have little impact on its ability to stimulate RNAPII occupancy at PPP sites. In addition, we demonstrate that two cancer-associated CSB mutations, which are located on the opposite side of the CSB-WHD away from its ubiquitin-binding pocket, impair CSB's ability to promote RNAPII occupancy at PPP sites. Taken together, these results suggest that CSB promotes RNAPII association with PPP sites in a manner requiring the CSB-WHD but independent of its ubiquitin-binding activity. These results further imply that CSB-mediated RNAPII occupancy at PPP sites is mechanistically separable from CSB-mediated repair of cisplatin-induced DNA damage.
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Affiliation(s)
| | | | | | | | - Xu-Dong Zhu
- Correspondence: ; Tel.: +1-905-525-9140 (ext. 27737)
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18
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Mystery of Expansion: DNA Metabolism and Unstable Repeats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1241:101-124. [PMID: 32383118 DOI: 10.1007/978-3-030-41283-8_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The mammalian genome mostly contains repeated sequences. Some of these repeats are in the regulatory elements of genes, and their instability, particularly the propensity to change the repeat unit number, is responsible for 36 well-known neurodegenerative human disorders. The mechanism of repeat expansion has been an unsolved question for more than 20 years. There are a few hypotheses describing models of mutation development. Every hypothesis is based on assumptions about unusual secondary structures that violate DNA metabolism processes in the cell. Some models are based on replication errors, and other models are based on mismatch repair or base excision repair errors. Additionally, it has been shown that epigenetic regulation of gene expression can influence the probability and frequency of expansion. In this review, we consider the molecular bases of repeat expansion disorders and discuss possible mechanisms of repeat expansion during cell metabolism.
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19
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Vessoni AT, Guerra CCC, Kajitani GS, Nascimento LLS, Garcia CCM. Cockayne Syndrome: The many challenges and approaches to understand a multifaceted disease. Genet Mol Biol 2020; 43:e20190085. [PMID: 32453336 PMCID: PMC7250278 DOI: 10.1590/1678-4685-gmb-2019-0085] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 01/15/2020] [Indexed: 01/04/2023] Open
Abstract
The striking and complex phenotype of Cockayne syndrome (CS) patients combines progeria-like features with developmental deficits. Since the establishment of the in vitro culture of skin fibroblasts derived from patients with CS in the 1970s, significant progress has been made in the understanding of the genetic alterations associated with the disease and their impact on molecular, cellular, and organismal functions. In this review, we provide a historic perspective on the research into CS by revisiting seminal papers in this field. We highlighted the great contributions of several researchers in the last decades, ranging from the cloning and characterization of CS genes to the molecular dissection of their roles in DNA repair, transcription, redox processes and metabolism control. We also provide a detailed description of all pathological mutations in genes ERCC6 and ERCC8 reported to date and their impact on CS-related proteins. Finally, we review the contributions (and limitations) of many genetic animal models to the study of CS and how cutting-edge technologies, such as cell reprogramming and state-of-the-art genome editing, are helping us to address unanswered questions.
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Affiliation(s)
| | - Camila Chaves Coelho Guerra
- Universidade Federal de Ouro Preto, Instituto de Ciências Exatas e
Biológicas, Núcleo de Pesquisa em Ciências Biológicas & Departamento de Ciências
Biológicas, Ouro Preto, MG, Brazil
| | - Gustavo Satoru Kajitani
- Universidade Federal de Ouro Preto, Instituto de Ciências Exatas e
Biológicas, Núcleo de Pesquisa em Ciências Biológicas & Departamento de Ciências
Biológicas, Ouro Preto, MG, Brazil
- Universidade de São Paulo, Instituto de Ciências Biomédicas,
Departamento de Microbiologia, São Paulo,SP, Brazil
| | - Livia Luz Souza Nascimento
- Universidade de São Paulo, Instituto de Ciências Biomédicas,
Departamento de Microbiologia, São Paulo,SP, Brazil
| | - Camila Carrião Machado Garcia
- Universidade Federal de Ouro Preto, Instituto de Ciências Exatas e
Biológicas, Núcleo de Pesquisa em Ciências Biológicas & Departamento de Ciências
Biológicas, Ouro Preto, MG, Brazil
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20
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van der Weegen Y, Golan-Berman H, Mevissen TET, Apelt K, González-Prieto R, Goedhart J, Heilbrun EE, Vertegaal ACO, van den Heuvel D, Walter JC, Adar S, Luijsterburg MS. The cooperative action of CSB, CSA, and UVSSA target TFIIH to DNA damage-stalled RNA polymerase II. Nat Commun 2020; 11:2104. [PMID: 32355176 PMCID: PMC7192910 DOI: 10.1038/s41467-020-15903-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 03/27/2020] [Indexed: 12/13/2022] Open
Abstract
The response to DNA damage-stalled RNA polymerase II (RNAPIIo) involves the assembly of the transcription-coupled repair (TCR) complex on actively transcribed strands. The function of the TCR proteins CSB, CSA and UVSSA and the manner in which the core DNA repair complex, including transcription factor IIH (TFIIH), is recruited are largely unknown. Here, we define the assembly mechanism of the TCR complex in human isogenic knockout cells. We show that TCR is initiated by RNAPIIo-bound CSB, which recruits CSA through a newly identified CSA-interaction motif (CIM). Once recruited, CSA facilitates the association of UVSSA with stalled RNAPIIo. Importantly, we find that UVSSA is the key factor that recruits the TFIIH complex in a manner that is stimulated by CSB and CSA. Together these findings identify a sequential and highly cooperative assembly mechanism of TCR proteins and reveal the mechanism for TFIIH recruitment to DNA damage-stalled RNAPIIo to initiate repair. The response to DNA damage-stalled RNA polymerase II leads to the assembly of the transcription-coupled repair (TCR) complex on actively transcribed strands. Here, the authors reveal the complex assembly mechanism of the TCR complex in human cells.
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Affiliation(s)
- Yana van der Weegen
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Hadar Golan-Berman
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel-Canada, The Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, Jerusalem, 91120, Israel
| | - Tycho E T Mevissen
- Howard Hughes Medical Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Katja Apelt
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Román González-Prieto
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Joachim Goedhart
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands
| | - Elisheva E Heilbrun
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel-Canada, The Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, Jerusalem, 91120, Israel
| | - Alfred C O Vertegaal
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Diana van den Heuvel
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - Johannes C Walter
- Howard Hughes Medical Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Sheera Adar
- Department of Microbiology and Molecular Genetics, The Institute for Medical Research Israel-Canada, The Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, Jerusalem, 91120, Israel
| | - Martijn S Luijsterburg
- Department of Human Genetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands.
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21
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Okur MN, Lee JH, Osmani W, Kimura R, Demarest TG, Croteau DL, Bohr VA. Cockayne syndrome group A and B proteins function in rRNA transcription through nucleolin regulation. Nucleic Acids Res 2020; 48:2473-2485. [PMID: 31970402 PMCID: PMC7049711 DOI: 10.1093/nar/gkz1242] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 12/30/2019] [Accepted: 12/31/2019] [Indexed: 02/07/2023] Open
Abstract
Cockayne Syndrome (CS) is a rare neurodegenerative disease characterized by short stature, accelerated aging and short lifespan. Mutations in two human genes, ERCC8/CSA and ERCC6/CSB, are causative for CS and their protein products, CSA and CSB, while structurally unrelated, play roles in DNA repair and other aspects of DNA metabolism in human cells. Many clinical and molecular features of CS remain poorly understood, and it was observed that CSA and CSB regulate transcription of ribosomal DNA (rDNA) genes and ribosome biogenesis. Here, we investigate the dysregulation of rRNA synthesis in CS. We report that Nucleolin (Ncl), a nucleolar protein that regulates rRNA synthesis and ribosome biogenesis, interacts with CSA and CSB. In addition, CSA induces ubiquitination of Ncl, enhances binding of CSB to Ncl, and CSA and CSB both stimulate the binding of Ncl to rDNA and subsequent rRNA synthesis. CSB and CSA also increase RNA Polymerase I loading to the coding region of the rDNA and this is Ncl dependent. These findings suggest that CSA and CSB are positive regulators of rRNA synthesis via Ncl regulation. Most CS patients carry mutations in CSA and CSB and present with similar clinical features, thus our findings provide novel insights into disease mechanism.
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Affiliation(s)
- Mustafa N Okur
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Jong-Hyuk Lee
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Wasif Osmani
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Risako Kimura
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Tyler G Demarest
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Deborah L Croteau
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
- Danish Center for Healthy Aging, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
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22
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Zhu Q, Ding N, Wei S, Li P, Wani G, He J, Wani AA. USP7-mediated deubiquitination differentially regulates CSB but not UVSSA upon UV radiation-induced DNA damage. Cell Cycle 2019; 19:124-141. [PMID: 31775559 DOI: 10.1080/15384101.2019.1695996] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cockayne syndrome group B (CSB) protein participates in transcription-coupled nucleotide excision repair. The stability of CSB is known to be regulated by ubiquitin-specific protease 7 (USP7). Yet, whether USP7 acts as a deubiquitinating enzyme for CSB is not clear. Here, we demonstrate that USP7 deubiquitinates CSB to maintain its levels after ultraviolet (UV)-induced DNA damage. While both CSB and UV-stimulated scaffold protein A (UVSSA) exhibit a biphasic decrease and recovery upon UV irradiation, only CSB recovery depends on USP7, which physically interacts with and deubiquitinates CSB. Meanwhile, CSB overexpression stabilizes UVSSA, but decrease UVSSA's presence in nuclease-releasable/soluble chromatin, and increase the presence of ubiquitinated UVSSA in insoluble chromatin alongside CSB-ubiquitin conjugates. Remarkably, CSB overexpression also decreases CSB association with USP7 and UVSSA in soluble chromatin. UVSSA exists in several ubiquitinated forms, of which mono-ubiquitinated form and other ubiquitinated UVSSA forms are detectable upon 6xHistidine tag-based purification. The ubiquitinated UVSSA forms, however, are not cleavable by USP7 in vitro. Furthermore, USP7 disruption does not affect RNA synthesis but decreases the recovery of RNA synthesis following UV exposure. These results reveal a role of USP7 as a CSB deubiquitinating enzyme for fine-tuning the process of TC-NER in human cells.
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Affiliation(s)
- Qianzheng Zhu
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Nan Ding
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Shengcai Wei
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Ping Li
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Gulzar Wani
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jinshan He
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Altaf A Wani
- Department of Radiology, The Ohio State University College of Medicine, Columbus, OH, USA.,Department of Molecular and Cellular Biochemistry, The Ohio State University College of Medicine, Columbus, OH, USA.,James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH, USA
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23
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Lans H, Hoeijmakers JHJ, Vermeulen W, Marteijn JA. The DNA damage response to transcription stress. Nat Rev Mol Cell Biol 2019; 20:766-784. [DOI: 10.1038/s41580-019-0169-4] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2019] [Indexed: 12/30/2022]
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24
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Boetefuer EL, Lake RJ, Fan HY. Mechanistic insights into the regulation of transcription and transcription-coupled DNA repair by Cockayne syndrome protein B. Nucleic Acids Res 2019; 46:7471-7479. [PMID: 30032309 PMCID: PMC6125617 DOI: 10.1093/nar/gky660] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/10/2018] [Indexed: 12/24/2022] Open
Abstract
Cockayne syndrome protein B (CSB) is a member of the SNF2/SWI2 ATPase family and is essential for transcription-coupled nucleotide excision DNA repair (TC-NER). CSB also plays critical roles in transcription regulation. CSB can hydrolyze ATP in a DNA-dependent manner, alter protein-DNA contacts and anneal DNA strands. How the different biochemical activities of CSB are utilized in these cellular processes have only begun to become clear in recent years. Mutations in the gene encoding CSB account for majority of the Cockayne syndrome cases, which result in extreme sun sensitivity, premature aging features and/or abnormalities in neurology and development. Here, we summarize and integrate recent biochemical, structural, single-molecule and somatic cell genetic studies that have advanced our understanding of CSB. First, we review studies on the mechanisms that regulate the different biochemical activities of CSB. Next, we summarize how CSB is targeted to regulate transcription under different growth conditions. We then discuss recent advances in our understanding of how CSB regulates transcription mechanistically. Lastly, we summarize the various roles that CSB plays in the different steps of TC-NER, integrating the results of different studies and proposing a model as to how CSB facilitates TC-NER.
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Affiliation(s)
- Erica L Boetefuer
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert J Lake
- Department of Internal Medicine, Division of Molecular Medicine, Program in Cancer Genetics, Epigenetics and Genomics, University of New Mexico Comprehensive Cancer Center, Albuquerque, NM 87131, USA
| | - Hua-Ying Fan
- Department of Internal Medicine, Division of Molecular Medicine, Program in Cancer Genetics, Epigenetics and Genomics, University of New Mexico Comprehensive Cancer Center, Albuquerque, NM 87131, USA
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25
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Iyama T, Okur MN, Golato T, McNeill DR, Lu H, Hamilton R, Raja A, Bohr VA, Wilson DM. Regulation of the Intranuclear Distribution of the Cockayne Syndrome Proteins. Sci Rep 2018; 8:17490. [PMID: 30504782 PMCID: PMC6269539 DOI: 10.1038/s41598-018-36027-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/01/2018] [Indexed: 12/04/2022] Open
Abstract
Cockayne syndrome (CS) is an inherited disorder that involves photosensitivity, developmental defects, progressive degeneration and characteristics of premature aging. Evidence indicates primarily nuclear roles for the major CS proteins, CSA and CSB, specifically in DNA repair and RNA transcription. We reveal herein a complex regulation of CSB targeting that involves three major consensus signals: NLS1 (aa467-481), which directs nuclear and nucleolar localization in cooperation with NoLS1 (aa302-341), and NLS2 (aa1038-1055), which seemingly optimizes nuclear enrichment. CSB localization to the nucleolus was also found to be important for full UVC resistance. CSA, which does not contain any obvious targeting sequences, was adversely affected (i.e. presumably destabilized) by any form of truncation. No inter-coordination between the subnuclear localization of CSA and CSB was observed, implying that this aspect does not underlie the clinical features of CS. The E3 ubiquitin ligase binding partner of CSA, DDB1, played an important role in CSA stability (as well as DDB2), and facilitated CSA association with chromatin following UV irradiation; yet did not affect CSB chromatin binding. We also observed that initial recruitment of CSB to DNA interstrand crosslinks is similar in the nucleoplasm and nucleolus, although final accumulation is greater in the former. Whereas assembly of CSB at sites of DNA damage in the nucleolus was not affected by RNA polymerase I inhibition, stable retention at these sites of presumed repair was abrogated. Our studies reveal a multi-faceted regulation of the intranuclear dynamics of CSA and CSB that plays a role in mediating their cellular functions.
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Affiliation(s)
- Teruaki Iyama
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - Mustafa N Okur
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - Tyler Golato
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - Daniel R McNeill
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - Huiming Lu
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - Royce Hamilton
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - Aishwarya Raja
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA
| | - David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Ste. 100, Baltimore, MD, 21224, USA.
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26
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Boetefuer EL, Lake RJ, Dreval K, Fan HY. Poly(ADP-ribose) polymerase 1 (PARP1) promotes oxidative stress-induced association of Cockayne syndrome group B protein with chromatin. J Biol Chem 2018; 293:17863-17874. [PMID: 30266807 DOI: 10.1074/jbc.ra118.004548] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 09/25/2018] [Indexed: 01/08/2023] Open
Abstract
Cockayne syndrome protein B (CSB) is an ATP-dependent chromatin remodeler that relieves oxidative stress by regulating DNA repair and transcription. CSB is proposed to participate in base-excision repair (BER), the primary pathway for repairing oxidative DNA damage, but exactly how CSB participates in this process is unknown. It is also unclear whether CSB contributes to other repair pathways during oxidative stress. Here, using a patient-derived CS1AN-sv cell line, we examined how CSB is targeted to chromatin in response to menadione-induced oxidative stress, both globally and locus-specifically. We found that menadione-induced, global CSB-chromatin association does not require CSB's ATPase activity and is, therefore, mechanistically distinct from UV-induced CSB-chromatin association. Importantly, poly(ADP-ribose) polymerase 1 (PARP1) enhanced the kinetics of global menadione-induced CSB-chromatin association. We found that the major BER enzymes, 8-oxoguanine DNA glycosylase (OGG1) and apurinic/apyrimidinic endodeoxyribonuclease 1 (APE1), do not influence this association. Additionally, the level of γ-H2A histone family member X (γ-H2AX), a marker for dsDNA breaks, was not increased in menadione-treated cells. Therefore, our results support a model whereby PARP1 localizes to ssDNA breaks and recruits CSB to participate in DNA repair. Furthermore, this global CSB-chromatin association occurred independently of RNA polymerase II-mediated transcription elongation. However, unlike global CSB-chromatin association, both PARP1 knockdown and inhibition of transcription elongation interfered with menadione-induced CSB recruitment to specific genomic regions. This observation supports the hypothesis that CSB is also targeted to specific genomic loci to participate in transcriptional regulation in response to oxidative stress.
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Affiliation(s)
- Erica L Boetefuer
- From the Department of Internal Medicine, Division of Molecular Medicine, Program in Cancer Genetics, Epigenetics, and Genomics, University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87131; Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Robert J Lake
- From the Department of Internal Medicine, Division of Molecular Medicine, Program in Cancer Genetics, Epigenetics, and Genomics, University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87131
| | - Kostiantyn Dreval
- From the Department of Internal Medicine, Division of Molecular Medicine, Program in Cancer Genetics, Epigenetics, and Genomics, University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87131
| | - Hua-Ying Fan
- From the Department of Internal Medicine, Division of Molecular Medicine, Program in Cancer Genetics, Epigenetics, and Genomics, University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87131.
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Structural basis of DNA lesion recognition for eukaryotic transcription-coupled nucleotide excision repair. DNA Repair (Amst) 2018; 71:43-55. [PMID: 30174298 DOI: 10.1016/j.dnarep.2018.08.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Eukaryotic transcription-coupled nucleotide excision repair (TC-NER) is a pathway that removes DNA lesions capable of blocking RNA polymerase II (Pol II) transcription from the template strand. This process is initiated by lesion-arrested Pol II and the recruitment of Cockayne Syndrome B protein (CSB). In this review, we will focus on the lesion recognition steps of eukaryotic TC-NER and summarize the recent research progress toward understanding the structural basis of Pol II-mediated lesion recognition and Pol II-CSB interactions. We will discuss the roles of CSB in both TC-NER initiation and transcription elongation. Finally, we propose an updated model of tripartite lesion recognition and verification for TC-NER in which CSB ensures Pol II-mediated recognition of DNA lesions for TC-NER.
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Genome instability is a consequence of transcription deficiency in patients with bone marrow failure harboring biallelic ERCC6L2 variants. Proc Natl Acad Sci U S A 2018; 115:7777-7782. [PMID: 29987015 PMCID: PMC6064997 DOI: 10.1073/pnas.1803275115] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bone marrow failure (BMF) is an inherited life-threatening condition characterized by defective hematopoiesis, developmental abnormalities, and predisposition to cancer. BMF caused by ERCC6L2 mutations is considered to be a genome instability syndrome, because DNA repair is compromised in patient cells. In this study, we report BMF cases with biallelic disease-causing variants and provide evidence from patients’ cells that transcription deficiency can explain the genome instability. Specifically, we demonstrate that ERCC6L2 participates in RNA polymerase II-mediated transcription via interaction with DNA-dependent protein kinase (DNA-PK) and resolves DNA–RNA hybrids (R loops). Collectively, our data point to a causal mechanism in BMF in which patients with ERCC6L2 mutations are defective in the repair of transcription-associated DNA damage. Biallelic variants in the ERCC excision repair 6 like 2 gene (ERCC6L2) are known to cause bone marrow failure (BMF) due to defects in DNA repair and mitochondrial function. Here, we report on eight cases of BMF from five families harboring biallelic variants in ERCC6L2, two of whom present with myelodysplasia. We confirm that ERCC6L2 patients’ lymphoblastoid cell lines (LCLs) are hypersensitive to DNA-damaging agents that specifically activate the transcription coupled nucleotide excision repair (TCNER) pathway. Interestingly, patients’ LCLs are also hypersensitive to transcription inhibitors that interfere with RNA polymerase II (RNA Pol II) and display an abnormal delay in transcription recovery. Using affinity-based mass spectrometry we found that ERCC6L2 interacts with DNA-dependent protein kinase (DNA-PK), a regulatory component of the RNA Pol II transcription complex. Chromatin immunoprecipitation PCR studies revealed ERCC6L2 occupancy on gene bodies along with RNA Pol II and DNA-PK. Patients’ LCLs fail to terminate transcript elongation accurately upon DNA damage and display a significant increase in nuclear DNA–RNA hybrids (R loops). Collectively, we conclude that ERCC6L2 is involved in regulating RNA Pol II-mediated transcription via its interaction with DNA-PK to resolve R loops and minimize transcription-associated genome instability. The inherited BMF syndrome caused by biallelic variants in ERCC6L2 can be considered as a primary transcription deficiency rather than a DNA repair defect.
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Abstract
PURPOSE To present peripheral retinal vasculopathy and foveal ellipsoid zone abnormalities as novel fundus manifestations of Cockayne syndrome (CS), a rare autosomal recessive condition with well-described ophthalmic associations. METHODS Clinical examination, wide-field fundus photography, wide-field fundus autofluorescence, wide-field fluorescein angiography, and spectral domain optical coherence tomography (SD-OCT) were used to diagnose and document the patient's clinical presentation. RESULTS Our patient presented with postnatal growth delay, neurologic dysfunction, premature aging, dental anomalies, sensory neural hearing loss, and pigmentary retinopathy. This constellation of clinical features satisfies the clinical diagnostic criteria of CS Type 1. In addition to these well-known features, we used multimodal retinal imaging to perform an in-depth analysis of the retinal manifestations of CS and report peripheral vasculopathy and ellipsoid zone abnormality as two novel features which have not previously been described in conjunction with CS. CONCLUSION This case report is intended to assist physicians in making the correct diagnosis of this rare condition by reviewing the clinical diagnostic criteria and providing the most comprehensive fundus imaging of CS available in the literature to date.
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Affiliation(s)
- Matthew G J Trese
- *Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan; and †Department of Ophthalmology, Shiley Eye Center and Jacobs Retina Center, University of California, San Diego, La Jolla, California
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Structural basis for the initiation of eukaryotic transcription-coupled DNA repair. Nature 2017; 551:653-657. [PMID: 29168508 PMCID: PMC5907806 DOI: 10.1038/nature24658] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 10/18/2017] [Indexed: 12/19/2022]
Abstract
Eukaryotic transcription-coupled repair (TCR), or transcription-coupled nucleotide excision repair (TC-NER), is an important and well-conserved sub-pathway of nucleotide excision repair (NER) that preferentially removes DNA lesions from the template strand blocking RNA polymerase II (Pol II) translocation1,2. Cockayne syndrome group B protein in humans (CSB, or ERCC6), or its yeast orthologs (Rad26 in Saccharomyces cerevisiae and Rhp26 in Schizosaccharomyces pombe), is among the first proteins to be recruited to the lesion-arrested Pol II during initiation of eukaryotic TCR1,3–10. Mutations in CSB are associated with Cockayne syndrome, an autosomal-recessive neurologic disorder characterized by progeriod features, growth failure, and photosensitivity1. The molecular mechanism of eukaryotic TCR initiation remains elusive, with several long-standing questions unanswered: How do cells distinguish DNA lesion-arrested Pol II from other forms of arrested Pol II? How does CSB interact with the arrested Pol II complex? What is the role of CSB in TCR initiation? The lack of structures of CSB or the Pol II-CSB complex have hindered our ability to answer those questions. Here we report the first structure of S. cerevisiae Pol II-Rad26 complex solved by cryo-electron microscopy (cryo-EM). The structure reveals that Rad26 binds to the DNA upstream of Pol II where it dramatically alters its path. Our structural and functional data suggest that the conserved Swi2/Snf2-family core ATPase domain promotes forward movement of Pol II and elucidate key roles for Rad26/CSB in both TCR and transcription elongation.
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UV-induced proteolysis of RNA polymerase II is mediated by VCP/p97 segregase and timely orchestration by Cockayne syndrome B protein. Oncotarget 2017; 8:11004-11019. [PMID: 28036256 PMCID: PMC5355241 DOI: 10.18632/oncotarget.14205] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/20/2016] [Indexed: 11/25/2022] Open
Abstract
RNA polymerase II (RNAPII) acts as a damage sensor for transcription-coupled nucleotide excision repair (TC-NER) and undergoes proteolytic clearance from damaged chromatin by the ubiquitin-proteasome system (UPS). Here, we report that Valosin-containing protein (VCP)/p97, a druggable oncotarget, is essential for RNAPII's proteolytic clearance in mammalian cells. We show that inhibition of VCP/p97, or siRNA-mediated ablation of VCP/p97 and its cofactors UFD1 and UBXD7 severely impairs ultraviolet radiation (UVR)-induced RNAPII degradation. VCP/p97 interacts with RNAPII, and the interaction is enhanced by Cockayne syndrome B protein (CSB). However, the VCP/p97-mediated RNAPII proteolysis occurs independent of CSB. Surprisingly, CSB enhances UVR-induced RNAPII ubiquitination but delays its turnover. Additionally, VCP/p97-mediated RNAPII turnover occurs with and without Von Hippel-Lindau tumor suppressor protein (pVHL), a known substrate receptor of Elongin E3 ubiquitin ligase for RNAPII. Moreover, pVHL re-expression improves cell viability following UVR. Whereas, VCP/p97 inhibition decreases cell viability and enhances a low-dose UVR killing in presence of pVHL. These findings reveal a function of VCP/p97 segregase in UVR-induced RNAPII degradation in mammalian cells, and suggest a role of CSB in coordinating VCP/p97-mediated extraction of ubiquitinated RNAPII and CSB itself from chromatin.
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32
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Schuch AP, Moreno NC, Schuch NJ, Menck CFM, Garcia CCM. Sunlight damage to cellular DNA: Focus on oxidatively generated lesions. Free Radic Biol Med 2017; 107:110-124. [PMID: 28109890 DOI: 10.1016/j.freeradbiomed.2017.01.029] [Citation(s) in RCA: 229] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/11/2017] [Accepted: 01/17/2017] [Indexed: 12/19/2022]
Abstract
The routine and often unavoidable exposure to solar ultraviolet (UV) radiation makes it one of the most significant environmental DNA-damaging agents to which humans are exposed. Sunlight, specifically UVB and UVA, triggers various types of DNA damage. Although sunlight, mainly UVB, is necessary for the production of vitamin D, which is necessary for human health, DNA damage may have several deleterious consequences, such as cell death, mutagenesis, photoaging and cancer. UVA and UVB photons can be directly absorbed not only by DNA, which results in lesions, but also by the chromophores that are present in skin cells. This process leads to the formation of reactive oxygen species, which may indirectly cause DNA damage. Despite many decades of investigation, the discrimination among the consequences of these different types of lesions is not clear. However, human cells have complex systems to avoid the deleterious effects of the reactive species produced by sunlight. These systems include antioxidants, that protect DNA, and mechanisms of DNA damage repair and tolerance. Genetic defects in these mechanisms that have clear harmful effects in the exposed skin are found in several human syndromes. The best known of these is xeroderma pigmentosum (XP), whose patients are defective in the nucleotide excision repair (NER) and translesion synthesis (TLS) pathways. These patients are mainly affected due to UV-induced pyrimidine dimers, but there is growing evidence that XP cells are also defective in the protection against other types of lesions, including oxidized DNA bases. This raises a question regarding the relative roles of the various forms of sunlight-induced DNA damage on skin carcinogenesis and photoaging. Therefore, knowledge of what occurs in XP patients may still bring important contributions to the understanding of the biological impact of sunlight-induced deleterious effects on the skin cells.
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Affiliation(s)
- André Passaglia Schuch
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, 97110-970 Santa Maria, RS, Brazil.
| | - Natália Cestari Moreno
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-000 São Paulo, SP, Brazil.
| | - Natielen Jacques Schuch
- Departamento de Nutrição, Centro Universitário Franciscano, 97010-032 Santa Maria, RS, Brazil.
| | - Carlos Frederico Martins Menck
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-000 São Paulo, SP, Brazil.
| | - Camila Carrião Machado Garcia
- Núcleo de Pesquisa em Ciências Biológicas & Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, 35400-000 Ouro Preto, MG, Brazil.
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Zhu Q, Wani AA. Nucleotide Excision Repair: Finely Tuned Molecular Orchestra of Early Pre-incision Events. Photochem Photobiol 2016; 93:166-177. [PMID: 27696486 DOI: 10.1111/php.12647] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 09/15/2016] [Indexed: 12/14/2022]
Abstract
Nucleotide excision repair (NER) eliminates a broad variety of helix-distorting DNA lesions that can otherwise cause genomic instability. NER comprises two distinct subpathways: global genomic NER (GG-NER) operating throughout the genome, and transcription-coupled NER (TC-NER) preferentially removing DNA lesions from transcribing DNA strands of transcriptionally active genes. Several NER factors undergo post-translational modifications, including ubiquitination, occurring swiftly and reversibly at DNA lesion sites. Accumulating evidence indicates that ubiquitination not only orchestrates the spatio-temporal recruitment of key protein factors to DNA lesion sites but also the productive assembly of NER pre-incision complex. This review will be restricted to the latest conceptual understanding of ubiquitin-mediated regulation of initial damage sensors of NER, that is DDB, XPC, RNAPII and CSB. We project hypothetical NER models in which ubiquitin-specific segregase, valosin-containing protein (VCP)/p97, plays an essential role in timely extraction of the congregated DNA damage sensors to functionally facilitate the DNA lesion elimination from the genome.
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Affiliation(s)
- Qianzheng Zhu
- Department of Radiology, The Ohio State University, Columbus, OH
| | - Altaf A Wani
- Department of Radiology, The Ohio State University, Columbus, OH.,Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH.,James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH
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Zhang Y, Najmi SM, Schneider DA. Transcription factors that influence RNA polymerases I and II: To what extent is mechanism of action conserved? BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1860:246-255. [PMID: 27989933 DOI: 10.1016/j.bbagrm.2016.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/07/2016] [Accepted: 10/25/2016] [Indexed: 01/05/2023]
Abstract
In eukaryotic cells, nuclear RNA synthesis is accomplished by at least three unique, multisubunit RNA polymerases. The roles of these enzymes are generally partitioned into the synthesis of the three major classes of RNA: rRNA, mRNA, and tRNA for RNA polymerases I, II, and III respectively. Consistent with their unique cellular roles, each enzyme has a complement of specialized transcription factors and enzymatic properties. However, not all transcription factors have evolved to affect only one eukaryotic RNA polymerase. In fact, many factors have been shown to influence the activities of multiple nuclear RNA polymerases. This review focuses on a subset of these factors, specifically addressing the mechanisms by which these proteins influence RNA polymerases I and II.
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Affiliation(s)
- Yinfeng Zhang
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Saman M Najmi
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294
| | - David A Schneider
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294
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Cockayne syndrome group A and B proteins converge on transcription-linked resolution of non-B DNA. Proc Natl Acad Sci U S A 2016; 113:12502-12507. [PMID: 27791127 DOI: 10.1073/pnas.1610198113] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cockayne syndrome is a neurodegenerative accelerated aging disorder caused by mutations in the CSA or CSB genes. Although the pathogenesis of Cockayne syndrome has remained elusive, recent work implicates mitochondrial dysfunction in the disease progression. Here, we present evidence that loss of CSA or CSB in a neuroblastoma cell line converges on mitochondrial dysfunction caused by defects in ribosomal DNA transcription and activation of the DNA damage sensor poly-ADP ribose polymerase 1 (PARP1). Indeed, inhibition of ribosomal DNA transcription leads to mitochondrial dysfunction in a number of cell lines. Furthermore, machine-learning algorithms predict that diseases with defects in ribosomal DNA (rDNA) transcription have mitochondrial dysfunction, and, accordingly, this is found when factors involved in rDNA transcription are knocked down. Mechanistically, loss of CSA or CSB leads to polymerase stalling at non-B DNA in a neuroblastoma cell line, in particular at G-quadruplex structures, and recombinant CSB can melt G-quadruplex structures. Indeed, stabilization of G-quadruplex structures activates PARP1 and leads to accelerated aging in Caenorhabditis elegans In conclusion, this work supports a role for impaired ribosomal DNA transcription in Cockayne syndrome and suggests that transcription-coupled resolution of secondary structures may be a mechanism to repress spurious activation of a DNA damage response.
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36
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Pascucci B, D'Errico M, Romagnoli A, De Nuccio C, Savino M, Pietraforte D, Lanzafame M, Calcagnile AS, Fortini P, Baccarini S, Orioli D, Degan P, Visentin S, Stefanini M, Isidoro C, Fimia GM, Dogliotti E. Overexpression of parkin rescues the defective mitochondrial phenotype and the increased apoptosis of Cockayne Syndrome A cells. Oncotarget 2016; 8:102852-102867. [PMID: 29262528 PMCID: PMC5732694 DOI: 10.18632/oncotarget.9913] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 05/26/2016] [Indexed: 01/01/2023] Open
Abstract
The ERCC8/CSA gene encodes a WD-40 repeat protein (CSA) that is part of a E3-ubiquitin ligase/COP9 signalosome complex. When mutated, CSA causes the Cockayne Syndrome group A (CS-A), a rare recessive progeroid disorder characterized by sun sensitivity and neurodevelopmental abnormalities. CS-A cells features include ROS hyperproduction, accumulation of oxidative genome damage, mitochondrial dysfunction and increased apoptosis that may contribute to the neurodegenerative process. In this study, we show that CSA localizes to mitochondria and specifically interacts with the mitochondrial fission protein dynamin-related protein (DRP1) that is hyperactivated when CSA is defective. Increased fission is not counterbalanced by increased mitophagy in CS-A cells thus leading to accumulation of fragmented mitochondria. However, when mitochondria are challenged with the mitochondrial toxin carbonyl cyanide m-chloro phenyl hydrazine, CS-A fibroblasts undergo mitophagy as efficiently as normal fibroblasts, suggesting that this process remains targetable to get rid of damaged mitochondria. Indeed, when basal mitophagy was potentiated by overexpressing Parkin in CSA deficient cells, a significant rescue of the dysfunctional mitochondrial phenotype was observed. Importantly, Parkin overexpression not only reactivates basal mitophagy, but plays also an anti-apoptotic role by significantly reducing the translocation of Bax at mitochondria in CS-A cells. These findings provide new mechanistic insights into the role of CSA in mitochondrial maintenance and might open new perspectives for therapeutic approaches.
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Affiliation(s)
- Barbara Pascucci
- Institute of Crystallography, Consiglio Nazionale delle Ricerche, Monterotondo Stazione, Rome, Italy.,Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Mariarosaria D'Errico
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Alessandra Romagnoli
- Department Epidemiology and Preclinical Research, INMI L. Spallanzani IRCCS, Rome, Italy
| | - Chiara De Nuccio
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Miriam Savino
- Laboratory of Molecular Pathology, Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Donatella Pietraforte
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Manuela Lanzafame
- Institute of Molecular Genetics, Consiglio Nazionale delle Ricerche, Pavia, Italy
| | - Angelo Salvatore Calcagnile
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Paola Fortini
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Sara Baccarini
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Donata Orioli
- Institute of Molecular Genetics, Consiglio Nazionale delle Ricerche, Pavia, Italy
| | - Paolo Degan
- IRCCS Azienda Ospedaliera Universitaria San Martino-IST-Istituto Nazionale per la Ricerca sul Cancro, Largo Rosanna Benzi, Genova, Italy
| | - Sergio Visentin
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
| | - Miria Stefanini
- Institute of Molecular Genetics, Consiglio Nazionale delle Ricerche, Pavia, Italy
| | - Ciro Isidoro
- Laboratory of Molecular Pathology, Department of Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Gian Maria Fimia
- Department Epidemiology and Preclinical Research, INMI L. Spallanzani IRCCS, Rome, Italy.,Department of Biological and Environmental Sciences and Technologies (DiSTeBA), Università del Salento, Lecce, Italy
| | - Eugenia Dogliotti
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, Rome, Italy
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He J, Zhu Q, Wani G, Sharma N, Wani AA. Valosin-containing Protein (VCP)/p97 Segregase Mediates Proteolytic Processing of Cockayne Syndrome Group B (CSB) in Damaged Chromatin. J Biol Chem 2016; 291:7396-408. [PMID: 26826127 DOI: 10.1074/jbc.m115.705350] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Indexed: 11/06/2022] Open
Abstract
Cockayne syndrome group A and B (CSB) proteins act in transcription-coupled repair, a subpathway of nucleotide excision repair. Here we demonstrate that valosin-containing protein (VCP)/p97 segregase functions in ultraviolet radiation (UVR)-induced ubiquitin-mediated CSB degradation. We show that VCP/p97 inhibition and siRNA-mediated ablation of VCP/p97 and its cofactors UFD1 and UBXD7 impair CSB degradation. VCP/p97 inhibition also results in the accumulation of CSB in chromatin. Moreover, VCP/p97 interacts with both native and ubiquitin-conjugated forms of CSB. The localized cellular UVR exposures lead to VCP/p97 accumulation at DNA damage spots, forming distinct UVR-induced foci. However, manifestation of VCP/p97 foci is independent of CSB and UBXD7. Furthermore, VCP/p97 and UBXD7 associate with the Cockayne syndrome group A-DDB1-Cul4A complex, an E3 ligase responsible for CSB ubiquitination. Compromising proteasome and VCP/p97 function allows accumulation of both native and ubiquitinated CSB and results in an increase of UBXD7, proteasomal RPN2, and Sug1 in the chromatin compartment. Surprisingly, both biochemical inhibition and genetic defect of VCP/p97 enhance the recovery of RNA synthesis following UVR, whereas both VCP/p97 and proteasome inhibitions decrease cell viability. Our findings reveal a new role of VCP/p97 segregase in the timely processing of ubiquitinated CSB from damaged chromatin.
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Affiliation(s)
| | | | | | | | - Altaf A Wani
- From the Departments of Radiology and Molecular and Cellular Biochemistry and James Cancer Hospital and Solove Research Institute, Ohio State University, Columbus, Ohio 43210
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Transcription coupled nucleotide excision repair in the yeast Saccharomyces cerevisiae: The ambiguous role of Rad26. DNA Repair (Amst) 2015; 36:43-48. [DOI: 10.1016/j.dnarep.2015.09.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Sin Y, Tanaka K, Saijo M. The C-terminal Region and SUMOylation of Cockayne Syndrome Group B Protein Play Critical Roles in Transcription-coupled Nucleotide Excision Repair. J Biol Chem 2015; 291:1387-97. [PMID: 26620705 DOI: 10.1074/jbc.m115.683235] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Indexed: 11/06/2022] Open
Abstract
Cockayne syndrome (CS) is a recessive disorder that results in deficiencies in transcription-coupled nucleotide excision repair (TC-NER), a subpathway of nucleotide excision repair, and cells from CS patients exhibit hypersensitivity to UV light. CS group B protein (CSB), which is the gene product of one of the genes responsible for CS, belongs to the SWI2/SNF2 DNA-dependent ATPase family and has an ATPase domain and an ubiquitin-binding domain (UBD) in the central region and the C-terminal region, respectively. The C-terminal region containing the UBD is essential for the functions of CSB. In this study, we generated several CSB deletion mutants and analyzed the functions of the C-terminal region of CSB in TC-NER. Not only the UBD but also the C-terminal 30-amino acid residues were required for UV light resistance and TC-NER. This region was needed for the interaction of CSB with RNA polymerase II, the translocation of CS group A protein to the nuclear matrix, and the association of CSB with chromatin after UV irradiation. CSB was modified by small ubiquitin-like modifier 2/3 in a UV light-dependent manner. This modification was abolished in a CSB mutant lacking the C-terminal 30 amino acid residues. However, the substitution of lysine residues in this region with arginine did not affect SUMOylation or TC-NER. By contrast, substitution of a lysine residue in the N-terminal region with arginine decreased SUMOylation and resulted in cells with defects in TC-NER. These results indicate that both the most C-terminal region and SUMOylation are important for the functions of CSB in TC-NER.
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Affiliation(s)
- Yooksil Sin
- From the Graduate School of Frontier Biosciences, Osaka University, Yamadaoka 1-3, Suita, Osaka 565-0871, Japan
| | - Kiyoji Tanaka
- From the Graduate School of Frontier Biosciences, Osaka University, Yamadaoka 1-3, Suita, Osaka 565-0871, Japan
| | - Masafumi Saijo
- From the Graduate School of Frontier Biosciences, Osaka University, Yamadaoka 1-3, Suita, Osaka 565-0871, Japan
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Iyama T, Wilson DM. Elements That Regulate the DNA Damage Response of Proteins Defective in Cockayne Syndrome. J Mol Biol 2015; 428:62-78. [PMID: 26616585 DOI: 10.1016/j.jmb.2015.11.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
Abstract
Cockayne syndrome (CS) is a premature aging disorder characterized by developmental defects, multisystem progressive degeneration and sensitivity to ultraviolet light. CS is divided into two primary complementation groups, A and B, with the CSA and CSB proteins presumably functioning in DNA repair and transcription. Using laser microirradiation and confocal microscopy, we characterized the nature and regulation of the CS protein response to oxidative DNA damage, double-strand breaks (DSBs), angelicin monoadducts and trioxsalen interstrand crosslinks (ICLs). Our data indicate that CSB recruitment is influenced by the type of DNA damage and is most rapid and robust as follows: ICLs>DSBs>monoadducts>oxidative lesions. Transcription inhibition reduced accumulation of CSB at sites of monoadducts and ICLs, but it did not affect recruitment to (although slightly affected retention at) oxidative damage. Inhibition of histone deacetylation altered the dynamics of CSB assembly, suggesting a role for chromatin status in the response to DNA damage, whereas the proteasome inhibitor MG132 had no effect. The C-terminus of CSB and, in particular, its ubiquitin-binding domain were critical to recruitment, while the N-terminus and a functional ATPase domain played a minor role at best in facilitating protein accumulation. Although the absence of CSA had no effect on CSB recruitment, CSA itself localized at sites of ICLs, DSBs and monoadducts but not at oxidative lesions. Our results reveal molecular components of the CS protein response and point to a major involvement of complex lesions in the pathology of CS.
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Affiliation(s)
- Teruaki Iyama
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 21224, USA
| | - David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 21224, USA.
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41
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Xu L, Wang W, Chong J, Shin JH, Xu J, Wang D. RNA polymerase II transcriptional fidelity control and its functional interplay with DNA modifications. Crit Rev Biochem Mol Biol 2015; 50:503-19. [PMID: 26392149 DOI: 10.3109/10409238.2015.1087960] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Accurate genetic information transfer is essential for life. As a key enzyme involved in the first step of gene expression, RNA polymerase II (Pol II) must maintain high transcriptional fidelity while it reads along DNA template and synthesizes RNA transcript in a stepwise manner during transcription elongation. DNA lesions or modifications may lead to significant changes in transcriptional fidelity or transcription elongation dynamics. In this review, we will summarize recent progress toward understanding the molecular basis of RNA Pol II transcriptional fidelity control and impacts of DNA lesions and modifications on Pol II transcription elongation.
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Affiliation(s)
- Liang Xu
- a Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of California San Diego , La Jolla , CA , USA
| | - Wei Wang
- a Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of California San Diego , La Jolla , CA , USA
| | - Jenny Chong
- a Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of California San Diego , La Jolla , CA , USA
| | - Ji Hyun Shin
- a Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of California San Diego , La Jolla , CA , USA
| | - Jun Xu
- a Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of California San Diego , La Jolla , CA , USA
| | - Dong Wang
- a Skaggs School of Pharmacy and Pharmaceutical Sciences, The University of California San Diego , La Jolla , CA , USA
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42
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Barnum KJ, O'Connell MJ. Molecular mechanisms involved in initiation of the DNA damage response. Mol Cell Oncol 2015; 2:e970065. [PMID: 27308403 PMCID: PMC4905235 DOI: 10.4161/23723548.2014.970065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/04/2014] [Accepted: 09/06/2014] [Indexed: 11/19/2022]
Abstract
DNA is subject to a wide variety of damage. In order to maintain genomic integrity, cells must respond to this damage by activating repair and cell cycle checkpoint pathways. The initiating events in the DNA damage response entail recognition of the lesion and the assembly of DNA damage response complexes at the DNA. Here, we review what is known about these processes for various DNA damage pathways.
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Affiliation(s)
- Kevin J Barnum
- Department of Oncological Sciences and the Graduate School of Biomedical Sciences; Icahn School of Medicine at Mount Sinai ; New York, NY USA
| | - Matthew J O'Connell
- Department of Oncological Sciences and the Graduate School of Biomedical Sciences; Icahn School of Medicine at Mount Sinai ; New York, NY USA
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43
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Regulation of the Rhp26ERCC6/CSB chromatin remodeler by a novel conserved leucine latch motif. Proc Natl Acad Sci U S A 2014; 111:18566-71. [PMID: 25512493 DOI: 10.1073/pnas.1420227112] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CSB/ERCC6 (Cockayne syndrome B protein/excision repair cross-complementation group 6), a member of a subfamily of SWI2/SNF2 (SWItch/sucrose nonfermentable)-related chromatin remodelers, plays crucial roles in gene expression and the maintenance of genome integrity. Here, we report the mechanism of the autoregulation of Rhp26, which is the homolog of CSB/ERCC6 in Schizosaccharomyces pombe. We identified a novel conserved protein motif, termed the "leucine latch," at the N terminus of Rhp26. The leucine latch motif mediates the autoinhibition of the ATPase and chromatin-remodeling activities of Rhp26 via its interaction with the core ATPase domain. Moreover, we found that the C terminus of the protein counteracts this autoinhibition and that both the N- and C-terminal regions of Rhp26 are needed for its proper function in DNA repair in vivo. The presence of the leucine latch motif in organisms ranging from yeast to humans suggests a conserved mechanism for the autoregulation of CSB/ERCC6 despite the otherwise highly divergent nature of the N- and C-terminal regions.
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44
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Li W, Selvam K, Ko T, Li S. Transcription bypass of DNA lesions enhances cell survival but attenuates transcription coupled DNA repair. Nucleic Acids Res 2014; 42:13242-53. [PMID: 25389266 PMCID: PMC4245964 DOI: 10.1093/nar/gku1150] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Transcription-coupled DNA repair (TCR) is a subpathway of nucleotide excision repair (NER) dedicated to rapid removal of DNA lesions in the transcribed strand of actively transcribed genes. The precise nature of the TCR signal and how the repair machinery gains access to lesions imbedded in stalled RNA polymerase II (RNAP II) complexes in eukaryotic cells are still enigmatic. RNAP II has an intrinsic capacity for transcription bypass of DNA lesions by incorporation or misincorporation of nucleotides across the lesions. It has been suggested that transcription bypass of lesions, which exposes the lesions, may be required for TCR. Here, we show that E1103G mutation of Rpb1, the largest subunit of RNAP II, which promotes transcription bypass of UV-induced cyclobutane pyrimidine dimers (CPDs), increases survival of UV irradiated yeast cells but attenuates TCR. The increased cell survival is independent of any NER subpathways. In contrast, G730D mutation of Rpb1, which impairs transcription bypass of CPDs, enhances TCR. Our results suggest that transcription bypass of lesions attenuates TCR but enhances cell tolerance to DNA lesions. Efficient stalling of RNAP II is essential for efficient TCR.
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Affiliation(s)
- Wentao Li
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Kathiresan Selvam
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Tengyu Ko
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Shisheng Li
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
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Abstract
Rad26p is a SWI/SNF-like ATPase in yeast, and is conserved among eukaryotes. Both Rad26p and its human homolog CSB (Cockayne syndrome group B) are involved in regulation of chromatin structure, transcription and DNA repair. Thus, mutations or malfunctions of these proteins have significant effects on cellular functions. Mutations in CSB are associated with Cockayne syndrome (CS) that is characterized by heterogeneous pathologies such as mental and physical retardation, sun sensitivity, premature aging, muscular and skeletal abnormalities, and progressive decline in neurological and cognitive functions. Therefore, many research groups focused their studies to understand the mechanisms of Rad26p/CSB functions to illuminate the molecular bases of CS. These studies have provided significant functional and mechanistic insights of Rad26p/CSB in regulation of gene expression and genome integrity as described here.
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Affiliation(s)
- Shivani Malik
- a Department of Biochemistry and Molecular Biology ; Southern Illinois University School of Medicine ; Carbondale , IL USA
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Shehata L, Simeonov DR, Raams A, Wolfe L, Vanderver A, Li X, Huang Y, Garner S, Boerkoel CF, Thurm A, Herman GE, Tifft CJ, He M, Jaspers NGJ, Gahl WA. ERCC6 dysfunction presenting as progressive neurological decline with brain hypomyelination. Am J Med Genet A 2014; 164A:2892-900. [PMID: 25251875 DOI: 10.1002/ajmg.a.36709] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/23/2014] [Indexed: 12/14/2022]
Abstract
Mutations in ERCC6 are associated with growth failure, intellectual disability, neurological dysfunction and deterioration, premature aging, and photosensitivity. We describe siblings with biallelic ERCC6 mutations (NM_000124.2:c. [543+4delA];[2008C>T]) and brain hypomyelination, microcephaly, cognitive decline, and skill regression but without photosensitivity or progeria. DNA repair assays on cultured skin fibroblasts confirmed a defect of transcription-coupled nucleotide excision repair and increased ultraviolet light sensitivity. This report expands the disease spectrum associated with ERCC6 mutations.
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Affiliation(s)
- Laila Shehata
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, Maryland
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Abstract
Nucleotide excision repair (NER) is a key component of the DNA damage response (DDR) and it is essential to safeguard genome integrity against genotoxic insults. The regulation of NER is primarily mediated by protein post-translational modifications (PTMs). The NER machinery removes a wide spectrum of DNA helix distorting lesions, including those induced by solar radiation, through two sub-pathways: global genome nucleotide excision repair (GG-NER) and transcription coupled nucleotide excision repair (TC-NER). Severe clinical consequences associated with inherited NER defects, including premature ageing, neurodegeneration and extreme cancer-susceptibility, underscore the biological relevance of NER. In the last two decades most of the core NER machinery has been elaborately described, shifting attention to molecular mechanisms that either facilitate NER in the context of chromatin or promote the timely and accurate interplay between NER factors and various post-translational modifications. In this review, we summarize and discuss the latest findings in NER. In particular, we focus on emerging factors and novel molecular mechanisms by which NER is regulated.
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48
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Aydin ÖZ, Marteijn JA, Ribeiro-Silva C, Rodríguez López A, Wijgers N, Smeenk G, van Attikum H, Poot RA, Vermeulen W, Lans H. Human ISWI complexes are targeted by SMARCA5 ATPase and SLIDE domains to help resolve lesion-stalled transcription. Nucleic Acids Res 2014; 42:8473-85. [PMID: 24990377 PMCID: PMC4117783 DOI: 10.1093/nar/gku565] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chromatin compaction of deoxyribonucleic acid (DNA) presents a major challenge to the detection and removal of DNA damage. Helix-distorting DNA lesions that block transcription are specifically repaired by transcription-coupled nucleotide excision repair, which is initiated by binding of the CSB protein to lesion-stalled RNA polymerase II. Using live cell imaging, we identify a novel function for two distinct mammalian ISWI adenosine triphosphate (ATP)-dependent chromatin remodeling complexes in resolving lesion-stalled transcription. Human ISWI isoform SMARCA5/SNF2H and its binding partners ACF1 and WSTF are rapidly recruited to UV-C induced DNA damage to specifically facilitate CSB binding and to promote transcription recovery. SMARCA5 targeting to UV-C damage depends on transcription and histone modifications and requires functional SWI2/SNF2-ATPase and SLIDE domains. After initial recruitment to UV damage, SMARCA5 re-localizes away from the center of DNA damage, requiring its HAND domain. Our studies support a model in which SMARCA5 targeting to DNA damage-stalled transcription sites is controlled by an ATP-hydrolysis-dependent scanning and proofreading mechanism, highlighting how SWI2/SNF2 chromatin remodelers identify and bind nucleosomes containing damaged DNA.
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Affiliation(s)
- Özge Z Aydin
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Jurgen A Marteijn
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Cristina Ribeiro-Silva
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Aida Rodríguez López
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Nils Wijgers
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Godelieve Smeenk
- Department of Toxicogenetics, Leiden University Medical Center, Leiden, 2333 ZC, The Netherlands
| | - Haico van Attikum
- Department of Toxicogenetics, Leiden University Medical Center, Leiden, 2333 ZC, The Netherlands
| | - Raymond A Poot
- Department of Cell Biology, Medical Genetics Cluster, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Wim Vermeulen
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
| | - Hannes Lans
- Department of Genetics, Medical Genetics Cluster, Cancer Genomics Netherlands, Erasmus MC, Rotterdam, 3015 GE, The Netherlands
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49
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Seltzer LE, Paciorkowski AR. Genetic disorders associated with postnatal microcephaly. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2014; 166C:140-55. [PMID: 24839169 DOI: 10.1002/ajmg.c.31400] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Several genetic disorders are characterized by normal head size at birth, followed by deceleration in head growth resulting in postnatal microcephaly. Among these are classic disorders such as Angelman syndrome and MECP2-related disorder (formerly Rett syndrome), as well as more recently described clinical entities associated with mutations in CASK, CDKL5, CREBBP, and EP300 (Rubinstein-Taybi syndrome), FOXG1, SLC9A6 (Christianson syndrome), and TCF4 (Pitt-Hopkins syndrome). These disorders can be identified clinically by phenotyping across multiple neurodevelopmental and neurobehavioral realms, and enough data are available to recognize these postnatal microcephaly disorders as separate diagnostic entities in their own right. A second diagnostic grouping, comprised of Warburg MICRO syndrome, Cockayne syndrome, and Cerebral-oculo-facial skeletal syndrome, share similar features of somatic growth failure, ophthalmologic, and dysmorphologic features. Many postnatal microcephaly syndromes are caused by mutations in genes important in the regulation of gene expression in the developing forebrain and hindbrain, although important synaptic structural genes also play a role. This is an emerging group of disorders with a fascinating combination of brain malformations, specific epilepsies, movement disorders, and other complex neurobehavioral abnormalities.
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50
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Koch S, Garcia Gonzalez O, Assfalg R, Schelling A, Schäfer P, Scharffetter-Kochanek K, Iben S. Cockayne syndrome protein A is a transcription factor of RNA polymerase I and stimulates ribosomal biogenesis and growth. Cell Cycle 2014; 13:2029-37. [PMID: 24781187 PMCID: PMC4111694 DOI: 10.4161/cc.29018] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mutations in the Cockayne syndrome A (CSA) protein account for 20% of Cockayne syndrome (CS) cases, a childhood disorder of premature aging and early death. Hitherto, CSA has exclusively been described as DNA repair factor of the transcription-coupled branch of nucleotide excision repair. Here we show a novel function of CSA as transcription factor of RNA polymerase I in the nucleolus. Knockdown of CSA reduces pre-rRNA synthesis by RNA polymerase I. CSA associates with RNA polymerase I and the active fraction of the rDNA and stimulates re-initiation of rDNA transcription by recruiting the Cockayne syndrome proteins TFIIH and CSB. Moreover, compared with CSA deficient parental CS cells, CSA transfected CS cells reveal significantly more rRNA with induced growth and enhanced global translation. A previously unknown global dysregulation of ribosomal biogenesis most likely contributes to the reduced growth and premature aging of CS patients.
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Affiliation(s)
- Sylvia Koch
- Department of Dermatology and Allergic Diseases; University of Ulm; Ulm, Germany
| | - Omar Garcia Gonzalez
- Department of Dermatology and Allergic Diseases; University of Ulm; Ulm, Germany
| | - Robin Assfalg
- Department of Dermatology and Allergic Diseases; University of Ulm; Ulm, Germany
| | - Adrian Schelling
- Department of Dermatology and Allergic Diseases; University of Ulm; Ulm, Germany
| | - Patrick Schäfer
- Department of Dermatology and Allergic Diseases; University of Ulm; Ulm, Germany
| | | | - Sebastian Iben
- Department of Dermatology and Allergic Diseases; University of Ulm; Ulm, Germany
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