1
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Casati P, Gomez MS. Chromatin dynamics during DNA damage and repair in plants: new roles for old players. J Exp Bot 2021; 72:4119-4131. [PMID: 33206978 DOI: 10.1093/jxb/eraa551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/12/2020] [Indexed: 06/11/2023]
Abstract
The genome of plants is organized into chromatin. The chromatin structure regulates the rates of DNA metabolic processes such as replication, transcription, DNA recombination, and repair. Different aspects of plant growth and development are regulated by changes in chromatin status by the action of chromatin-remodeling activities. Recent data have also shown that many of these chromatin-associated proteins participate in different aspects of the DNA damage response, regulating DNA damage and repair, cell cycle progression, programmed cell death, and entry into the endocycle. In this review, we present different examples of proteins and chromatin-modifying enzymes with roles during DNA damage responses, demonstrating that rapid changes in chromatin structure are essential to maintain genome stability.
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Affiliation(s)
- Paula Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI), Universidad Nacional de Rosario, Suipacha, Rosario, Argentina
| | - Maria Sol Gomez
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolas Cabrera, Cantoblanco, Madrid, Spain
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2
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Kang Y, Cho C, Lee KS, Song JJ, Lee JY. Single-Molecule Imaging Reveals the Mechanism Underlying Histone Loading of Schizosaccharomyces pombe AAA+ ATPase Abo1. Mol Cells 2021; 44:79-87. [PMID: 33658433 PMCID: PMC7941004 DOI: 10.14348/molcells.2021.2242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/26/2021] [Accepted: 02/09/2021] [Indexed: 11/27/2022] Open
Abstract
Chromatin dynamics is essential for maintaining genomic integrity and regulating gene expression. Conserved bromodomain-containing AAA+ ATPases play important roles in nucleosome organization as histone chaperones. Recently, the high-resolution cryo-electron microscopy structures of Schizosaccharomyces pombe Abo1 revealed that it forms a hexameric ring and undergoes a conformational change upon ATP hydrolysis. In addition, single-molecule imaging demonstrated that Abo1 loads H3-H4 histones onto DNA in an ATP hydrolysis-dependent manner. However, the molecular mechanism by which Abo1 loads histones remains unknown. Here, we investigated the details concerning Abo1-mediated histone loading onto DNA and the Abo1- DNA interaction using single-molecule imaging techniques and biochemical assays. We show that Abo1 does not load H2A-H2B histones. Interestingly, Abo1 deposits multiple copies of H3-H4 histones as the DNA length increases and requires at least 80 bp DNA. Unexpectedly, Abo1 weakly binds DNA regardless of ATP, and neither histone nor DNA stimulates the ATP hydrolysis activity of Abo1. Based on our results, we propose an allosteric communication model in which the ATP hydrolysis of Abo1 changes the configuration of histones to facilitate their deposition onto DNA.
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Affiliation(s)
- Yujin Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
- These authors contributed equally to this work
| | - Carol Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- These authors contributed equally to this work
| | - Kyung Suk Lee
- Department of Physics Education, Kongju National University, Gongju 32588, Korea
| | - Ji-Joon Song
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Ja Yil Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Korea
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3
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Aleksandrov R, Hristova R, Stoynov S, Gospodinov A. The Chromatin Response to Double-Strand DNA Breaks and Their Repair. Cells 2020; 9:cells9081853. [PMID: 32784607 PMCID: PMC7464352 DOI: 10.3390/cells9081853] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 02/07/2023] Open
Abstract
Cellular DNA is constantly being damaged by numerous internal and external mutagenic factors. Probably the most severe type of insults DNA could suffer are the double-strand DNA breaks (DSBs). They sever both DNA strands and compromise genomic stability, causing deleterious chromosomal aberrations that are implicated in numerous maladies, including cancer. Not surprisingly, cells have evolved several DSB repair pathways encompassing hundreds of different DNA repair proteins to cope with this challenge. In eukaryotic cells, DSB repair is fulfilled in the immensely complex environment of the chromatin. The chromatin is not just a passive background that accommodates the multitude of DNA repair proteins, but it is a highly dynamic and active participant in the repair process. Chromatin alterations, such as changing patterns of histone modifications shaped by numerous histone-modifying enzymes and chromatin remodeling, are pivotal for proficient DSB repair. Dynamic chromatin changes ensure accessibility to the damaged region, recruit DNA repair proteins, and regulate their association and activity, contributing to DSB repair pathway choice and coordination. Given the paramount importance of DSB repair in tumorigenesis and cancer progression, DSB repair has turned into an attractive target for the development of novel anticancer therapies, some of which have already entered the clinic.
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4
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Crickard JB, Moevus CJ, Kwon Y, Sung P, Greene EC. Rad54 Drives ATP Hydrolysis-Dependent DNA Sequence Alignment during Homologous Recombination. Cell 2020; 181:1380-1394.e18. [PMID: 32502392 DOI: 10.1016/j.cell.2020.04.056] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/07/2020] [Accepted: 04/29/2020] [Indexed: 12/30/2022]
Abstract
Homologous recombination (HR) helps maintain genome integrity, and HR defects give rise to disease, especially cancer. During HR, damaged DNA must be aligned with an undamaged template through a process referred to as the homology search. Despite decades of study, key aspects of this search remain undefined. Here, we use single-molecule imaging to demonstrate that Rad54, a conserved Snf2-like protein found in all eukaryotes, switches the search from the diffusion-based pathways characteristic of the basal HR machinery to an active process in which DNA sequences are aligned via an ATP-dependent molecular motor-driven mechanism. We further demonstrate that Rad54 disrupts the donor template strands, enabling the search to take place within a migrating DNA bubble-like structure that is bound by replication protein A (RPA). Our results reveal that Rad54, working together with RPA, fundamentally alters how DNA sequences are aligned during HR.
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Affiliation(s)
- J Brooks Crickard
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Corentin J Moevus
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Eric C Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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5
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Gsell C, Richly H, Coin F, Naegeli H. A chromatin scaffold for DNA damage recognition: how histone methyltransferases prime nucleosomes for repair of ultraviolet light-induced lesions. Nucleic Acids Res 2020; 48:1652-1668. [PMID: 31930303 PMCID: PMC7038933 DOI: 10.1093/nar/gkz1229] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/18/2019] [Accepted: 12/23/2019] [Indexed: 02/07/2023] Open
Abstract
The excision of mutagenic DNA adducts by the nucleotide excision repair (NER) pathway is essential for genome stability, which is key to avoiding genetic diseases, premature aging, cancer and neurologic disorders. Due to the need to process an extraordinarily high damage density embedded in the nucleosome landscape of chromatin, NER activity provides a unique functional caliper to understand how histone modifiers modulate DNA damage responses. At least three distinct lysine methyltransferases (KMTs) targeting histones have been shown to facilitate the detection of ultraviolet (UV) light-induced DNA lesions in the difficult to access DNA wrapped around histones in nucleosomes. By methylating core histones, these KMTs generate docking sites for DNA damage recognition factors before the chromatin structure is ultimately relaxed and the offending lesions are effectively excised. In view of their function in priming nucleosomes for DNA repair, mutations of genes coding for these KMTs are expected to cause the accumulation of DNA damage promoting cancer and other chronic diseases. Research on the question of how KMTs modulate DNA repair might pave the way to the development of pharmacologic agents for novel therapeutic strategies.
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Affiliation(s)
- Corina Gsell
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Winterthurerstrasse 260, 8057 Zurich, Switzerland
| | - Holger Richly
- Boehringer Ingelheim Pharma, Department of Molecular Biology, Birkendorfer Str. 65, 88397 Biberach an der Riß, Germany
| | - Frédéric Coin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Equipe Labélisée Ligue contre le Cancer, Illkirch Cedex, Strasbourg, France
| | - Hanspeter Naegeli
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Winterthurerstrasse 260, 8057 Zurich, Switzerland
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6
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Xue C, Daley JM, Xue X, Steinfeld J, Kwon Y, Sung P, Greene EC. Single-molecule visualization of human BLM helicase as it acts upon double- and single-stranded DNA substrates. Nucleic Acids Res 2019; 47:11225-11237. [PMID: 31544923 PMCID: PMC6868385 DOI: 10.1093/nar/gkz810] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/06/2019] [Accepted: 09/17/2019] [Indexed: 11/12/2022] Open
Abstract
Bloom helicase (BLM) and its orthologs are essential for the maintenance of genome integrity. BLM defects represent the underlying cause of Bloom Syndrome, a rare genetic disorder that is marked by strong cancer predisposition. BLM deficient cells accumulate extensive chromosomal aberrations stemming from dysfunctions in homologous recombination (HR). BLM participates in several HR stages and helps dismantle potentially harmful HR intermediates. However, much remains to be learned about the molecular mechanisms of these BLM-mediated regulatory effects. Here, we use DNA curtains to directly visualize the activity of BLM helicase on single molecules of DNA. Our data show that BLM is a robust helicase capable of rapidly (∼70-80 base pairs per second) unwinding extensive tracts (∼8-10 kilobases) of double-stranded DNA (dsDNA). Importantly, we find no evidence for BLM activity on single-stranded DNA (ssDNA) that is bound by replication protein A (RPA). Likewise, our results show that BLM can neither associate with nor translocate on ssDNA that is bound by the recombinase protein RAD51. Moreover, our data reveal that the presence of RAD51 also blocks BLM translocation on dsDNA substrates. We discuss our findings within the context of potential regulator roles for BLM helicase during DNA replication and repair.
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Affiliation(s)
- Chaoyou Xue
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - James M Daley
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Xiaoyu Xue
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Justin Steinfeld
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Eric C Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
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7
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Melters DP, Pitman M, Rakshit T, Dimitriadis EK, Bui M, Papoian GA, Dalal Y. Intrinsic elasticity of nucleosomes is encoded by histone variants and calibrated by their binding partners. Proc Natl Acad Sci U S A 2019; 116:24066-24074. [PMID: 31712435 PMCID: PMC6883791 DOI: 10.1073/pnas.1911880116] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Histone variants fine-tune transcription, replication, DNA damage repair, and faithful chromosome segregation. Whether and how nucleosome variants encode unique mechanical properties to their cognate chromatin structures remains elusive. Here, using in silico and in vitro nanoindentation methods, extending to in vivo dissections, we report that histone variant nucleosomes are intrinsically more elastic than their canonical counterparts. Furthermore, binding proteins, which discriminate between histone variant nucleosomes, suppress this innate elasticity and also compact chromatin. Interestingly, when we overexpress the binding proteins in vivo, we also observe increased compaction of chromatin enriched for histone variant nucleosomes, correlating with diminished access. Taken together, these data suggest a plausible link between innate mechanical properties possessed by histone variant nucleosomes, the adaptability of chromatin states in vivo, and the epigenetic plasticity of the underlying locus.
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Affiliation(s)
- Daniël P Melters
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Mary Pitman
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
- Department of Chemistry and Biochemistry, Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742
| | - Tatini Rakshit
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Emilios K Dimitriadis
- Scanning Probe Microscopy Unit, Biomedical Engineering and Physical Science Shared Resource, National Institute for Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892
| | - Minh Bui
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Garegin A Papoian
- Department of Chemistry and Biochemistry, Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742;
| | - Yamini Dalal
- Laboratory Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892;
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8
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Jang S, Kumar N, Beckwitt EC, Kong M, Fouquerel E, Rapić-Otrin V, Prasad R, Watkins SC, Khuu C, Majumdar C, David SS, Wilson SH, Bruchez MP, Opresko PL, Van Houten B. Damage sensor role of UV-DDB during base excision repair. Nat Struct Mol Biol 2019; 26:695-703. [PMID: 31332353 DOI: 10.1038/s41594-019-0261-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 05/28/2019] [Indexed: 12/22/2022]
Abstract
UV-DDB, a key protein in human global nucleotide excision repair (NER), binds avidly to abasic sites and 8-oxo-guanine (8-oxoG), suggesting a noncanonical role in base excision repair (BER). We investigated whether UV-DDB can stimulate BER for these two common forms of DNA damage, 8-oxoG and abasic sites, which are repaired by 8-oxoguanine glycosylase (OGG1) and apurinic/apyrimidinic endonuclease (APE1), respectively. UV-DDB increased both OGG1 and APE1 strand cleavage and stimulated subsequent DNA polymerase β-gap filling activity by 30-fold. Single-molecule real-time imaging revealed that UV-DDB forms transient complexes with OGG1 or APE1, facilitating their dissociation from DNA. Furthermore, UV-DDB moves to sites of 8-oxoG repair in cells, and UV-DDB depletion sensitizes cells to oxidative DNA damage. We propose that UV-DDB is a general sensor of DNA damage in both NER and BER pathways, facilitating damage recognition in the context of chromatin.
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9
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Ren M, Cheng Y, Duan Q, Zhou C. Transesterification Reaction and the Repair of Embedded Ribonucleotides in DNA Are Suppressed upon the Assembly of DNA into Nucleosome Core Particles †. Chem Res Toxicol 2019; 32:926-934. [PMID: 30990021 DOI: 10.1021/acs.chemrestox.9b00059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ribonucleotides can be incorporated into DNA through many different cellular processes, and abundant amounts of ribonucleotides are detected in genomic DNA. Embedded ribonucleotides lead to genomic instability through either spontaneous ribonucleotide cleavage via internal transesterification or by inducing mutagenesis, recombination, and chromosome rearrangements. Ribonucleotides misincorporated in genomic DNA can be removed by the ribonucleotide excision repair (RER) pathway in which RNase HII initiates the repair by cleaving the 5'-phosphate of the ribonucleotide. Herein, based on in vitro reconstituted nucleosome core particles (NCPs) containing a single ribonucleotide at different positions, we studied the kinetics of ribonucleotide cleavage via the internal transesterification reaction and repair of the ribonucleotides by RNase HII in NCPs. Our results show that ribonucleotide cleavage via the internal transesterification in NCPs is suppressed compared to that in free DNA. DNA bending and structural rigidity account for the suppressed ribonucleotide cleavage in NCPs. Ribonucleotide repair by RNase HII in NCPs exhibits a strong correlation between the translational and rotational positions of the ribonucleotides. An embedded ribonucleotide located at the entry site while facing outward in NCP is repaired as efficiently as that in free DNA. However, the repair of those located in the central part of NCPs and facing inward are inhibited by up to 273-fold relative to those in free dsDNA. The difference in repair efficiency appears to arise from their different accessibility to repair enzymes in NCPs. This study reveals that a ribonucleotide misincorporated in DNA assembled into NCPs is protected against cleavage. Hence, the spontaneous cleavage of the misincorporated ribonucleotides under physiological conditions is not an essential threat to the stability of chromatin DNA. Instead, their decreased repair efficiency in NCPs may result in numerous and persistent ribonucleotides in genomic DNA, which could exert other deleterious effects on DNA such as mutagenesis and recombination.
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Affiliation(s)
- Mengtian Ren
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Yiran Cheng
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Qian Duan
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
| | - Chuanzheng Zhou
- State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, College of Chemistry , Nankai University , Tianjin 300071 , China
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10
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Xue C, Wang W, Crickard JB, Moevus CJ, Kwon Y, Sung P, Greene EC. Regulatory control of Sgs1 and Dna2 during eukaryotic DNA end resection. Proc Natl Acad Sci U S A 2019; 116:6091-100. [PMID: 30850524 DOI: 10.1073/pnas.1819276116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In the repair of DNA double-strand breaks by homologous recombination, the DNA break ends must first be processed into 3' single-strand DNA overhangs. In budding yeast, end processing requires the helicase Sgs1 (BLM in humans), the nuclease/helicase Dna2, Top3-Rmi1, and replication protein A (RPA). Here, we use single-molecule imaging to visualize Sgs1-dependent end processing in real-time. We show that Sgs1 is recruited to DNA ends through Top3-Rmi1-dependent or -independent means, and in both cases Sgs1 is maintained in an immoble state at the DNA ends. Importantly, the addition of Dna2 triggers processive Sgs1 translocation, but DNA resection only occurs when RPA is also present. We also demonstrate that the Sgs1-Dna2-Top3-Rmi1-RPA ensemble can efficiently disrupt nucleosomes, and that Sgs1 itself possesses nucleosome remodeling activity. Together, these results shed light on the regulatory interplay among conserved protein factors that mediate the nucleolytic processing of DNA ends in preparation for homologous recombination-mediated chromosome damage repair.
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11
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Chakraborty S, Pandita RK, Hambarde S, Mattoo AR, Charaka V, Ahmed KM, Iyer SP, Hunt CR, Pandita TK. SMARCAD1 Phosphorylation and Ubiquitination Are Required for Resection during DNA Double-Strand Break Repair. iScience 2018; 2:123-135. [PMID: 29888761 PMCID: PMC5993204 DOI: 10.1016/j.isci.2018.03.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/16/2018] [Accepted: 02/28/2018] [Indexed: 02/08/2023] Open
Abstract
The chromatin remodeling factor SMARCAD1, an SWI/SNF ATPase family member, has a role in 5' end resection at DNA double-strand breaks (DSBs) to produce single-strand DNA (ssDNA), a critical step for subsequent checkpoint and repair factor loading to remove DNA damage. However, the mechanistic details of SMARCAD1 coupling to the DNA damage response and repair pathways remains unknown. Here we report that SMARCAD1 is recruited to DNA DSBs through an ATM-dependent process. Depletion of SMARCAD1 reduces ionizing radiation (IR)-induced repairosome foci formation and DSB repair by homologous recombination (HR). IR induces SMARCAD1 phosphorylation at a conserved T906 by ATM kinase, a modification essential for SMARCAD1 recruitment to DSBs. Interestingly, T906 phosphorylation is also important for SMARCAD1 ubiquitination by RING1 at K905. Both these post-translational modifications are critical for regulating the role of SMARCAD1 in DNA end resection, HR-mediated repair, and cell survival after DNA damage.
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Affiliation(s)
- Sharmistha Chakraborty
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA.
| | - Raj K Pandita
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Shashank Hambarde
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Abid R Mattoo
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Vijaya Charaka
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Kazi M Ahmed
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Swaminathan P Iyer
- Department of Hematology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Clayton R Hunt
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA
| | - Tej K Pandita
- Department of Radiation Oncology, Houston Methodist Cancer Center, The Houston Methodist Research Institute, Weill Cornell Medical College, Houston, TX 77030, USA.
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12
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Rüthemann P, Balbo Pogliano C, Codilupi T, Garajovà Z, Naegeli H. Chromatin remodeler CHD1 promotes XPC-to-TFIIH handover of nucleosomal UV lesions in nucleotide excision repair. EMBO J 2017; 36:3372-3386. [PMID: 29018037 DOI: 10.15252/embj.201695742] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 08/10/2017] [Accepted: 09/08/2017] [Indexed: 12/27/2022] Open
Abstract
Ultraviolet (UV) light induces mutagenic cyclobutane pyrimidine dimers (CPDs) in nucleosomal DNA that is tightly wrapped around histone octamers. How global-genome nucleotide excision repair (GG-NER) processes CPDs despite that this chromatin arrangement is poorly understood. An increased chromatin association of CHD1 (chromodomain helicase DNA-binding 1) upon UV irradiation indicated possible roles of this chromatin remodeler in the UV damage response. Immunoprecipitation of chromatin fragments revealed that CHD1 co-localizes in part with GG-NER factors. Chromatin fractionation showed that the UV-dependent recruitment of CHD1 occurs to UV lesions in histone-assembled nucleosomal DNA and that this CHD1 relocation requires the lesion sensor XPC (xeroderma pigmentosum group C). In situ immunofluorescence analyses further demonstrate that CHD1 facilitates substrate handover from XPC to the downstream TFIIH (transcription factor IIH). Consequently, CHD1 depletion slows down CPD excision and sensitizes cells to UV-induced cytotoxicity. The finding of a CHD1-driven lesion handover between sequentially acting GG-NER factors on nucleosomal histone octamers suggests that chromatin provides a recognition scaffold enabling the detection of a subset of CPDs.
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Affiliation(s)
- Peter Rüthemann
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Chiara Balbo Pogliano
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Tamara Codilupi
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Zuzana Garajovà
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Hanspeter Naegeli
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
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13
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Abstract
Advances in genomics technology have provided the means to probe myriad chromatin interactions at unprecedented spatial and temporal resolution. This has led to a profound understanding of nucleosome organization within the genome, revealing that nucleosomes are highly dynamic. Nucleosome dynamics are governed by a complex interplay of histone composition, histone post-translational modifications, nucleosome occupancy and positioning within chromatin, which are influenced by numerous regulatory factors, including general regulatory factors, chromatin remodellers, chaperones and polymerases. It is now known that these dynamics regulate diverse cellular processes ranging from gene transcription to DNA replication and repair.
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14
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Morel D, Almouzni G, Soria JC, Postel-Vinay S. Targeting chromatin defects in selected solid tumors based on oncogene addiction, synthetic lethality and epigenetic antagonism. Ann Oncol 2017; 28:254-269. [DOI: 10.1093/annonc/mdw552] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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15
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Abstract
DNA damage poses a constant threat to genome integrity taking a variety of shapes and arising by normal cellular metabolism or environmental insults. Human syndromes, characterized by increased cancer pre-disposition or early onset of age-related pathology and developmental abnormalities, often result from defective DNA damage responses and compromised genome integrity. Over the last decades intensive research worldwide has made important contributions to our understanding of the molecular mechanisms underlying genomic instability and has substantiated the importance of DNA repair in cancer prevention in the general population. In this chapter, we discuss Nucleotide Excision Repair pathway, the causative role of its components in disease-related pathology and recent technological achievements that decipher mutational landscapes and may facilitate pathological classification and personalized therapy.
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Abstract
The nucleus is a hub for gene expression and is a highly organized entity. The nucleoplasm is heterogeneous, owing to the preferential localization of specific metabolic factors, which lead to the definition of nuclear compartments or bodies. The genome is organized into chromosome territories, as well as heterochromatin and euchromatin domains. Recent observations have indicated that nuclear organization is important for maintaining genomic stability. For example, nuclear organization has been implicated in stabilizing damaged DNA, repair-pathway choice, and in preventing chromosomal rearrangements. Over the past decade, several studies have revealed that dynamic changes in the nuclear architecture are important during double-strand break repair. Stemming from work in yeast, relocation of a damaged site prior to repair appears to be at least partially conserved in multicellular eukaryotes. In this review, we will discuss genome and nucleoplasm architecture, particularly the importance of the nuclear periphery in genome stability. We will also discuss how the site of relocation regulates repair-pathway choice.
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Affiliation(s)
- Hicham Saad
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
| | - Jennifer A. Cobb
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
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17
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Olaussen KA, Postel-Vinay S. Predictors of chemotherapy efficacy in non-small-cell lung cancer: a challenging landscape. Ann Oncol 2016; 27:2004-2016. [PMID: 27502726 DOI: 10.1093/annonc/mdw321] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 08/02/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Conventional cytotoxic chemotherapy (CCC) is the backbone of non-small-cell lung cancer (NSCLC) treatment since decades and still represents a key element of the therapeutic armamentarium. Contrary to molecularly targeted therapies and immune therapies, for which predictive biomarkers of activity have been actively looked for and developed in parallel to the drug development process ('companion biomarkers'), no patient selection biomarker is currently available for CCC, precluding customizing treatment. MATERIALS AND METHODS We reviewed preclinical and clinical studies that assessed potential predictive biomarkers of CCC used in NSCLC (platinum, antimetabolites, topoisomerase inhibitors, and spindle poisons). Biomarker evaluation method, analytical validity, and robustness are described and challenged for each biomarker. RESULTS The best-validated predictive biomarkers for efficacy are currently ERCC1, RRM1, and TS for platinum agents, gemcitabine and pemetrexed, respectively. Other potential biomarkers include hENT1 for gemcitabine, class III β-tubulin for spindle poisons, TOP2A expression and CEP17 duplication (mostly studied for predicting anthracyclines efficacy) whose applicability concerning etoposide would deserve further evaluation. However, none of these biomarkers has till now been validated prospectively in an appropriately designed and powered randomised trial, and none of them is currently ready for implementation in routine clinical practice. CONCLUSION The search for predictive biomarkers to CCC has been proven challenging. If a plethora of biomarkers have been evaluated either in the preclinical or in the clinical setting, none of them is ready for clinical implementation yet. Considering that most mechanisms of resistance or sensitivity to CCC are multifactorial, a combinatorial approach might be relevant and further efforts are required.
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Affiliation(s)
- K A Olaussen
- INSERM, Unit U981, Gustave Roussy, Villejuif .,Faculty of Medicine, Univ Paris Sud, Université Paris-Saclay, Kremlin-Bicêtre
| | - S Postel-Vinay
- INSERM, Unit U981, Gustave Roussy, Villejuif.,Faculty of Medicine, Univ Paris Sud, Université Paris-Saclay, Kremlin-Bicêtre.,Drug Development Department (DITEP), Gustave Roussy, Villejuif, France
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18
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Abstract
DNA damage occurs within the chromatin environment, which ultimately participates in regulating DNA damage response (DDR) pathways and repair of the lesion. DNA damage activates a cascade of signaling events that extensively modulates chromatin structure and organization to coordinate DDR factor recruitment to the break and repair, whilst also promoting the maintenance of normal chromatin functions within the damaged region. For example, DDR pathways must avoid conflicts between other DNA-based processes that function within the context of chromatin, including transcription and replication. The molecular mechanisms governing the recognition, target specificity, and recruitment of DDR factors and enzymes to the fundamental repeating unit of chromatin, i.e., the nucleosome, are poorly understood. Here we present our current view of how chromatin recognition by DDR factors is achieved at the level of the nucleosome. Emerging evidence suggests that the nucleosome surface, including the nucleosome acidic patch, promotes the binding and activity of several DNA damage factors on chromatin. Thus, in addition to interactions with damaged DNA and histone modifications, nucleosome recognition by DDR factors plays a key role in orchestrating the requisite chromatin response to maintain both genome and epigenome integrity.
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Affiliation(s)
- Poonam Agarwal
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, 2506 Speedway Stop A5000, Austin, TX 78712, USA.,Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, 2506 Speedway Stop A5000, Austin, TX 78712, USA
| | - Kyle M Miller
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, 2506 Speedway Stop A5000, Austin, TX 78712, USA.,Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, University of Texas at Austin, 2506 Speedway Stop A5000, Austin, TX 78712, USA
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19
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Lottersberger F, Karssemeijer RA, Dimitrova N, de Lange T. 53BP1 and the LINC Complex Promote Microtubule-Dependent DSB Mobility and DNA Repair. Cell 2016; 163:880-93. [PMID: 26544937 DOI: 10.1016/j.cell.2015.09.057] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/14/2015] [Accepted: 09/28/2015] [Indexed: 01/13/2023]
Abstract
Increased mobility of chromatin surrounding double-strand breaks (DSBs) has been noted in yeast and mammalian cells but the underlying mechanism and its contribution to DSB repair remain unclear. Here, we use a telomere-based system to track DNA damage foci with high resolution in living cells. We find that the greater mobility of damaged chromatin requires 53BP1, SUN1/2 in the linker of the nucleoskeleton, and cytoskeleton (LINC) complex and dynamic microtubules. The data further demonstrate that the excursions promote non-homologous end joining of dysfunctional telomeres and implicated Nesprin-4 and kinesins in telomere fusion. 53BP1/LINC/microtubule-dependent mobility is also evident at irradiation-induced DSBs and contributes to the mis-rejoining of drug-induced DSBs in BRCA1-deficient cells showing that DSB mobility can be detrimental in cells with numerous DSBs. In contrast, under physiological conditions where cells have only one or a few lesions, DSB mobility is proposed to prevent errors in DNA repair.
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Affiliation(s)
- Francisca Lottersberger
- Laboratory for Cell Biology and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Roos Anna Karssemeijer
- Laboratory for Cell Biology and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Nadya Dimitrova
- Laboratory for Cell Biology and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Titia de Lange
- Laboratory for Cell Biology and Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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20
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Chereji RV, Kan TW, Grudniewska MK, Romashchenko AV, Berezikov E, Zhimulev IF, Guryev V, Morozov AV, Moshkin YM. Genome-wide profiling of nucleosome sensitivity and chromatin accessibility in Drosophila melanogaster. Nucleic Acids Res 2016; 44:1036-51. [PMID: 26429969 PMCID: PMC4756854 DOI: 10.1093/nar/gkv978] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/27/2015] [Accepted: 09/16/2015] [Indexed: 01/09/2023] Open
Abstract
Nucleosomal DNA is thought to be generally inaccessible to DNA-binding factors, such as micrococcal nuclease (MNase). Here, we digest Drosophila chromatin with high and low concentrations of MNase to reveal two distinct nucleosome types: MNase-sensitive and MNase-resistant. MNase-resistant nucleosomes assemble on sequences depleted of A/T and enriched in G/C-containing dinucleotides, whereas MNase-sensitive nucleosomes form on A/T-rich sequences found at transcription start and termination sites, enhancers and DNase I hypersensitive sites. Estimates of nucleosome formation energies indicate that MNase-sensitive nucleosomes tend to be less stable than MNase-resistant ones. Strikingly, a decrease in cell growth temperature of about 10°C makes MNase-sensitive nucleosomes less accessible, suggesting that observed variations in MNase sensitivity are related to either thermal fluctuations of chromatin fibers or the activity of enzymatic machinery. In the vicinity of active genes and DNase I hypersensitive sites nucleosomes are organized into periodic arrays, likely due to 'phasing' off potential barriers formed by DNA-bound factors or by nucleosomes anchored to their positions through external interactions. The latter idea is substantiated by our biophysical model of nucleosome positioning and energetics, which predicts that nucleosomes immediately downstream of transcription start sites are anchored and recapitulates nucleosome phasing at active genes significantly better than sequence-dependent models.
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Affiliation(s)
- Răzvan V Chereji
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tsung-Wai Kan
- Department of Biochemistry, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Magda K Grudniewska
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, 9713AD, The Netherlands
| | | | - Eugene Berezikov
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, 9713AD, The Netherlands
| | - Igor F Zhimulev
- Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk 630090, Russia
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Groningen, 9713AD, The Netherlands
| | - Alexandre V Morozov
- Department of Physics and Astronomy and BioMaPS Institute for Quantitative Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Yuri M Moshkin
- Department of Biochemistry, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands Institute of Cytology and Genetics, Siberian Branch of RAS, Novosibirsk 630090, Russia Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk 630090, Russia
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21
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Zhao X, Yang G, Toyooka T, Ibuki Y. New mechanism of γ-H2AX generation: Surfactant-induced actin disruption causes deoxyribonuclease I translocation to the nucleus and forms DNA double-strand breaks. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 2015; 794:1-7. [DOI: 10.1016/j.mrgentox.2015.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 09/12/2015] [Accepted: 09/18/2015] [Indexed: 10/23/2022]
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22
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Zhang N, Huang L, Tian J, Chen X, Ke F, Zheng M, Xu J, Wu L. A novel synthetic novobiocin analog, FM-Nov17, induces DNA damage in CML cells through generation of reactive oxygen species. Pharmacol Rep 2015; 68:423-8. [PMID: 26922548 DOI: 10.1016/j.pharep.2015.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/14/2015] [Accepted: 11/02/2015] [Indexed: 01/14/2023]
Abstract
OBJECTIVES To investigate the cytotoxicity of FM-Nov17 against chronic myeloid leukemia (CML) cells, we explored its underlying mechanisms mediating the induction of DNA damage and apoptotic cell death by reactive oxygen species (ROS). METHODS MTT assays were used to measure the proliferation-inhibition ratio of K562 and K562/G01 cells. Flow cytometry (FCM) was used to test the level of extracellular ROS, DNA damage, cell cycle progression and apoptosis. Western blotting was used to verify the amount of protein. RESULTS FM-Nov17 significantly inhibited the proliferation of K562 cells, with an IC50 of 58.28±0.304μM, and K562/G01 cells, with an IC50 of 62.36±0.136μM. FM-Nov17 significantly stimulated the generation of intracellular ROS, followed by the induction of DNA damage and the activation of the ATM-p53-r-H2AX pathway and checkpoint-related signals Chk1/Chk2, which led to increased numbers of cells in the S and G2/M phases of the cell cycle. Furthermore, FM-Nov17 induced apoptotic cell death by decreasing mitochondrial membrane potential and activating caspase-3 and PARP. The above effects were all prevented by the ROS scavenger N-acetylcysteine. CONCLUSIONS FM-Nov17-induces DNA damage and mitochondria-dependent cellular apoptosis in CML cells. The process is mediated by the generation of ROS.
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Affiliation(s)
- Nanwen Zhang
- Dept. of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Institute of Materia Medica, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Fujian Key Laboratory of Natural Medicine Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China
| | - Lisen Huang
- Dept. of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Institute of Materia Medica, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Fujian Key Laboratory of Natural Medicine Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China
| | - Jue Tian
- Dept. of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Institute of Materia Medica, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Fujian Key Laboratory of Natural Medicine Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China
| | - Xianling Chen
- Fujian Institute of Hematology, Union Hospital, FMU, Fuzhou, PR China
| | - Fang Ke
- Department of Pharmacochemistry, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China
| | - Ming Zheng
- Department of Anatomy, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China
| | - Jianhua Xu
- Dept. of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Institute of Materia Medica, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Fujian Key Laboratory of Natural Medicine Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China
| | - Lixian Wu
- Dept. of Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Institute of Materia Medica, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China; Fujian Key Laboratory of Natural Medicine Pharmacology, School of Pharmacy, Fujian Medical University (FMU), Fuzhou, PR China.
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23
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Abstract
How DNA damaged is formed, recognized, and repaired in chromatin is an area of intense study. To better understand the structure activity relationships of damaged chromatin, mono and dinucleosomes containing site-specific damage have been prepared and studied. This review will focus on the design, synthesis, and characterization of model systems of damaged chromatin for structural, physical, and enzymatic studies.
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24
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Torregrosa-Muñumer R, Goffart S, Haikonen JA, Pohjoismäki JLO. Low doses of ultraviolet radiation and oxidative damage induce dramatic accumulation of mitochondrial DNA replication intermediates, fork regression, and replication initiation shift. Mol Biol Cell 2015; 26:4197-208. [PMID: 26399294 PMCID: PMC4642854 DOI: 10.1091/mbc.e15-06-0390] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/14/2015] [Indexed: 12/14/2022] Open
Abstract
Oxidative damage is believed to cause pathological mitochondrial DNA (mtDNA) rearrangements. mtDNA damage induces specific changes in its maintenance, such as formation of x-junctions and changes in replication mode. The findings explain the significance of the different replication mechanisms that have been observed in mitochondria. Mitochondrial DNA is prone to damage by various intrinsic as well as environmental stressors. DNA damage can in turn cause problems for replication, resulting in replication stalling and double-strand breaks, which are suspected to be the leading cause of pathological mtDNA rearrangements. In this study, we exposed cells to subtle levels of oxidative stress or UV radiation and followed their effects on mtDNA maintenance. Although the damage did not influence mtDNA copy number, we detected a massive accumulation of RNA:DNA hybrid–containing replication intermediates, followed by an increase in cruciform DNA molecules, as well as in bidirectional replication initiation outside of the main replication origin, OH. Our results suggest that mitochondria maintain two different types of replication as an adaptation to different cellular environments; the RNA:DNA hybrid–involving replication mode maintains mtDNA integrity in tissues with low oxidative stress, and the potentially more error tolerant conventional strand-coupled replication operates when stress is high.
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Affiliation(s)
| | - Steffi Goffart
- Department of Biology, University of Eastern Finland, 80101 Joensuu, Finland
| | - Juha A Haikonen
- Department of Biology, University of Eastern Finland, 80101 Joensuu, Finland
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25
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Abstract
The demonstration of DNA damage excision and repair replication by Setlow, Howard-Flanders, Hanawalt and their colleagues in the early 1960s, constituted the discovery of the ubiquitous pathway of nucleotide excision repair (NER). The serial steps in NER are similar in organisms from unicellular bacteria to complex mammals and plants, and involve recognition of lesions, adducts or structures that disrupt the DNA double helix, removal of a short oligonucleotide containing the offending lesion, synthesis of a repair patch copying the opposite undamaged strand, and ligation, to restore the DNA to its original form. The transcription-coupled repair (TCR) subpathway of NER, discovered nearly two decades later, is dedicated to the removal of lesions from the template DNA strands of actively transcribed genes. In this review I will outline the essential factors and complexes involved in NER in humans, and will comment on additional factors and metabolic processes that affect the efficiency of this important process.
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Affiliation(s)
- Graciela Spivak
- Department of Biology, Stanford University, Stanford, CA 94305-5020,USA.
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26
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Abstract
The integrity of DNA molecules is constantly challenged. All organisms have developed mechanisms to detect and repair multiple types of DNA lesions. The basic principles of DNA damage repair (DDR) in prokaryotes and unicellular and multicellular eukaryotes are similar, but the association of DNA with nucleosomes in eukaryotic chromatin requires mechanisms that allow access of repair enzymes to the lesions. This is achieved by chromatin-remodeling factors, and their necessity for efficient DDR has recently been demonstrated for several organisms and repair pathways. Plants share many features of chromatin organization and DNA repair with fungi and animals, but they differ in other, important details, which are both interesting and relevant for our understanding of genome stability and genetic diversity. In this Update, we compare the knowledge of the role of chromatin and chromatin-modifying factors during DDR in plants with equivalent systems in yeast and humans. We emphasize plant-specific elements and discuss possible implications.
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Affiliation(s)
- Mattia Donà
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna Biocenter, 1030 Vienna, Austria
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna Biocenter, 1030 Vienna, Austria
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27
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Cai Y, Kropachev K, Terzidis MA, Masi A, Chatgilialoglu C, Shafirovich V, Geacintov NE, Broyde S. Differences in the Access of Lesions to the Nucleotide Excision Repair Machinery in Nucleosomes. Biochemistry 2015; 54:4181-5. [PMID: 26091016 DOI: 10.1021/acs.biochem.5b00564] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In nucleosomes, the access of DNA lesions to nucleotide excision repair is hindered by histone proteins. However, evidence that the nature of the DNA lesions may play a role in facilitating access is emerging, but these phenomena are not well-understood. We have used molecular dynamics simulations to elucidate the structural, dynamic, and energetic properties of the R and S 5'-8-cyclo-2'-dG and the (+)-cis-anti-B[a]P-dG lesions in a nucleosome. Our results show that the (+)-cis-anti-B[a]P-dG adduct is more dynamic and more destabilizing than the smaller and more constrained 5',8-cyclo-2'-dG lesions, suggesting more facile access to the more bulky (+)-cis-anti-B[a]P-dG lesion.
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Affiliation(s)
| | | | - Michael A Terzidis
- §Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, 40129, Italy
| | - Annalisa Masi
- §Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, 40129, Italy
| | - Chryssostomos Chatgilialoglu
- §Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Bologna, 40129, Italy.,∥Institute of Nanoscience and Nanotechnology, National Center for Scientific Research Demokritos, 15341 Agia, Paraskevi, Athens, Greece
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28
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Abstract
DNA damage poses a major threat to cell function and viability by compromising both genome and epigenome integrity. The DNA damage response indeed operates in the context of chromatin and relies on dynamic changes in chromatin organization. Here, we review the molecular bases of chromatin alterations in response to DNA damage, focusing on core histone mobilization in mammalian cells. Building on our current view of nucleosome dynamics in response to DNA damage, we highlight open challenges and avenues for future development. In particular, we discuss the different levels of regulation of chromatin plasticity during the DNA damage response and their potential impact on cell function and epigenome maintenance.
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29
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Mjelle R, Hegre SA, Aas PA, Slupphaug G, Drabløs F, Saetrom P, Krokan HE. Cell cycle regulation of human DNA repair and chromatin remodeling genes. DNA Repair (Amst) 2015; 30:53-67. [PMID: 25881042 DOI: 10.1016/j.dnarep.2015.03.007] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 03/03/2015] [Accepted: 03/20/2015] [Indexed: 01/10/2023]
Abstract
Maintenance of a genome requires DNA repair integrated with chromatin remodeling. We have analyzed six transcriptome data sets and one data set on translational regulation of known DNA repair and remodeling genes in synchronized human cells. These data are available through our new database: www.dnarepairgenes.com. Genes that have similar transcription profiles in at least two of our data sets generally agree well with known protein profiles. In brief, long patch base excision repair (BER) is enriched for S phase genes, whereas short patch BER uses genes essentially equally expressed in all cell cycle phases. Furthermore, most genes related to DNA mismatch repair, Fanconi anemia and homologous recombination have their highest expression in the S phase. In contrast, genes specific for direct repair, nucleotide excision repair, as well as non-homologous end joining do not show cell cycle-related expression. Cell cycle regulated chromatin remodeling genes were most frequently confined to G1/S and S. These include e.g. genes for chromatin assembly factor 1 (CAF-1) major subunits CHAF1A and CHAF1B; the putative helicases HELLS and ATAD2 that both co-activate E2F transcription factors central in G1/S-transition and recruit DNA repair and chromatin-modifying proteins and DNA double strand break repair proteins; and RAD54L and RAD54B involved in double strand break repair. TOP2A was consistently most highly expressed in G2, but also expressed in late S phase, supporting a role in regulating entry into mitosis. Translational regulation complements transcriptional regulation and appears to be a relatively common cell cycle regulatory mechanism for DNA repair genes. Our results identify cell cycle phases in which different pathways have highest activity, and demonstrate that periodically expressed genes in a pathway are frequently co-expressed. Furthermore, the data suggest that S phase expression and over-expression of some multifunctional chromatin remodeling proteins may set up feedback loops driving cancer cell proliferation.
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30
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Bennett G, Peterson CL. SWI/SNF recruitment to a DNA double-strand break by the NuA4 and Gcn5 histone acetyltransferases. DNA Repair (Amst) 2015; 30:38-45. [PMID: 25869823 DOI: 10.1016/j.dnarep.2015.03.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 12/19/2022]
Abstract
The DNA damage response to double-strand breaks (DSBs) is critical for cellular viability. Recent work has shown that a host of chromatin regulators are recruited to a DSB, and that they are important for the DNA damage response. However, the functional relationships between different chromatin regulators at DSBs remain unclear. Here we describe a conserved functional interaction among the chromatin remodeling enzyme, SWI/SNF, the NuA4 and Gcn5 histone acetyltransferases, and phosphorylation of histone H2A.X (γH2AX). Specifically, we find that the NuA4 and Gcn5 enzymes are both required for the robust recruitment of SWI/SNF to a DSB, which in turn promotes the phosphorylation of H2A.X.
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Affiliation(s)
- Gwendolyn Bennett
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01606, USA
| | - Craig L Peterson
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01606, USA.
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31
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Abstract
Ultraviolet (UV) radiation from sunlight is a major etiologic factor for skin cancer, the most prevalent cancer in the United States, as well as premature skin aging. In particular, UVB radiation causes formation of specific DNA damage photoproducts between pyrimidine bases. These DNA damage photoproducts are repaired by a process called nucleotide excision repair, also known as UV-induced DNA repair. When left unrepaired, UVB-induced DNA damage leads to accumulation of mutations, predisposing people to carcinogenesis as well as to premature aging. Genetic loss of nucleotide excision repair leads to severe disorders, namely, xeroderma pigmentosum (XP), trichothiodystrophy (TTD) and Cockayne syndrome (CS), which are associated with predisposition to skin carcinogenesis at a young age as well as developmental and neurological conditions. Regulation of nucleotide excision repair is an attractive avenue to preventing or reversing these detrimental consequences of impaired nucleotide excision repair. Here, we review recent studies on molecular mechanisms regulating nucleotide excision repair by extracellular cues and intracellular signaling pathways, with a special focus on the molecular regulation of individual repair factors.
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Affiliation(s)
- Palak Shah
- Department of Medicine, Section of Dermatology, University of Chicago, Chicago, IL
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32
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Qi W, Wang R, Chen H, Wang X, Xiao T, Boldogh I, Ba X, Han L, Zeng X. BRG1 promotes the repair of DNA double-strand breaks by facilitating the replacement of RPA with RAD51. J Cell Sci 2014; 128:317-30. [PMID: 25395584 DOI: 10.1242/jcs.159103] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
DNA double-strand breaks (DSBs) are a type of lethal DNA damage. The repair of DSBs requires tight coordination between the factors modulating chromatin structure and the DNA repair machinery. BRG1, the ATPase subunit of the chromatin remodelling complex Switch/Sucrose non-fermentable (SWI/SNF), is often linked to tumorigenesis and genome instability, and its role in DSB repair remains largely unclear. In the present study, we show that BRG1 is recruited to DSB sites and enhances DSB repair. Using DR-GFP and EJ5-GFP reporter systems, we demonstrate that BRG1 facilitates homologous recombination repair rather than nonhomologous end-joining (NHEJ) repair. Moreover, the BRG1-RAD52 complex mediates the replacement of RPA with RAD51 on single-stranded DNA (ssDNA) to initiate DNA strand invasion. Loss of BRG1 results in a failure of RAD51 loading onto ssDNA, abnormal homologous recombination repair and enhanced DSB-induced lethality. Our present study provides a mechanistic insight into how BRG1, which is known to be involved in chromatin remodelling, plays a substantial role in the homologous recombination repair pathway in mammalian cells.
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Affiliation(s)
- Wenjing Qi
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, #5268, Renmin Street, Changchun, Jilin, 130024, China
| | - Ruoxi Wang
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, #5268, Renmin Street, Changchun, Jilin, 130024, China
| | - Hongyu Chen
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, #5268, Renmin Street, Changchun, Jilin, 130024, China
| | - Xiaolin Wang
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, #5268, Renmin Street, Changchun, Jilin, 130024, China
| | - Ting Xiao
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, #5268, Renmin Street, Changchun, Jilin, 130024, China
| | - Istvan Boldogh
- Department of Microbiology and Immunology, Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Xueqing Ba
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, #5268, Renmin Street, Changchun, Jilin, 130024, China
| | - Liping Han
- Department of Bioscience, Changchun Normal University, #677, Changji Northroad, Changchun, Jilin, 130032, China
| | - Xianlu Zeng
- The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, School of Life Sciences, Northeast Normal University, #5268, Renmin Street, Changchun, Jilin, 130024, China
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Filipescu D, Müller S, Almouzni G. Histone H3 Variants and Their Chaperones During Development and Disease: Contributing to Epigenetic Control. Annu Rev Cell Dev Biol 2014; 30:615-46. [DOI: 10.1146/annurev-cellbio-100913-013311] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dan Filipescu
- Institut Curie, Centre de Recherche, Paris, F-75248 France; , ,
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Horigome C, Oma Y, Konishi T, Schmid R, Marcomini I, Hauer MH, Dion V, Harata M, Gasser SM. SWR1 and INO80 chromatin remodelers contribute to DNA double-strand break perinuclear anchorage site choice. Mol Cell 2014; 55:626-39. [PMID: 25066231 DOI: 10.1016/j.molcel.2014.06.027] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 05/05/2014] [Accepted: 06/17/2014] [Indexed: 11/23/2022]
Abstract
Persistent DNA double-strand breaks (DSBs) are recruited to the nuclear periphery in budding yeast. Both the Nup84 pore subcomplex and Mps3, an inner nuclear membrane (INM) SUN domain protein, have been implicated in DSB binding. It was unclear what, if anything, distinguishes the two potential sites of repair. Here, we characterize and distinguish the two binding sites. First, DSB-pore interaction occurs independently of cell-cycle phase and requires neither the chromatin remodeler INO80 nor recombinase Rad51 activity. In contrast, Mps3 binding is S and G2 phase specific and requires both factors. SWR1-dependent incorporation of Htz1 (H2A.Z) is necessary for break relocation to either site in both G1- and S-phase cells. Importantly, functional assays indicate that mutations in the two sites have additive repair defects, arguing that the two perinuclear anchorage sites define distinct survival pathways.
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Gupta A, Hunt CR, Hegde ML, Chakraborty S, Chakraborty S, Udayakumar D, Horikoshi N, Singh M, Ramnarain DB, Hittelman WN, Namjoshi S, Asaithamby A, Hazra TK, Ludwig T, Pandita RK, Tyler JK, Pandita TK. MOF phosphorylation by ATM regulates 53BP1-mediated double-strand break repair pathway choice. Cell Rep 2014; 8:177-89. [PMID: 24953651 DOI: 10.1016/j.celrep.2014.05.044] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 04/24/2014] [Accepted: 05/21/2014] [Indexed: 01/09/2023] Open
Abstract
Cell-cycle phase is a critical determinant of the choice between DNA damage repair by nonhomologous end-joining (NHEJ) or homologous recombination (HR). Here, we report that double-strand breaks (DSBs) induce ATM-dependent MOF (a histone H4 acetyl-transferase) phosphorylation (p-T392-MOF) and that phosphorylated MOF colocalizes with γ-H2AX, ATM, and 53BP1 foci. Mutation of the phosphorylation site (MOF-T392A) impedes DNA repair in S and G2 phase but not G1 phase cells. Expression of MOF-T392A also blocks the reduction in DSB-associated 53BP1 seen in wild-type S/G2 phase cells, resulting in enhanced 53BP1 and reduced BRCA1 association. Decreased BRCA1 levels at DSB sites correlates with defective repairosome formation, reduced HR repair, and decreased cell survival following irradiation. These data support a model whereby ATM-mediated MOF-T392 phosphorylation modulates 53BP1 function to facilitate the subsequent recruitment of HR repair proteins, uncovering a regulatory role for MOF in DSB repair pathway choice during S/G2 phase.
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Affiliation(s)
- Arun Gupta
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA
| | - Clayton R Hunt
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | | | - Sharmistha Chakraborty
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Sharmistha Chakraborty
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Durga Udayakumar
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Nobuo Horikoshi
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Mayank Singh
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Deepti B Ramnarain
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Walter N Hittelman
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sarita Namjoshi
- Department of Biochemistry, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Aroumougame Asaithamby
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tapas K Hazra
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Thomas Ludwig
- Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Raj K Pandita
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Jessica K Tyler
- Department of Biochemistry, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Tej K Pandita
- Deparment of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63108, USA; Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA.
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36
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Abstract
DNA damage signaling and repair machineries operate in a nuclear environment where DNA is wrapped around histone proteins and packaged into chromatin. Understanding how chromatin structure is restored together with the DNA sequence during DNA damage repair has been a topic of intense research. Indeed, chromatin integrity is central to cell functions and identity. However, chromatin shows remarkable plasticity in response to DNA damage. This review presents our current knowledge of chromatin dynamics in the mammalian cell nucleus in response to DNA double strand breaks and UV lesions. I provide an overview of the key players involved in regulating histone dynamics in damaged chromatin regions, focusing on histone chaperones and their concerted action with histone modifiers, chromatin remodelers and repair factors. I also discuss how these dynamics contribute to reshaping chromatin and, by altering the chromatin landscape, may affect the maintenance of epigenetic information.
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Affiliation(s)
- Sophie E Polo
- Epigenetics and Cell Fate Centre, UMR7216 CNRS, Paris Diderot University, 75205 Paris Cedex 13, France.
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Adam S, Polo SE, Almouzni G. How to restore chromatin structure and function in response to DNA damage--let the chaperones play: delivered on 9 July 2013 at the 38th FEBS Congress in St Petersburg, Russia. FEBS J 2014; 281:2315-23. [PMID: 24673849 DOI: 10.1111/febs.12793] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/25/2014] [Indexed: 01/07/2023]
Abstract
Histone deposition onto DNA assisted by specific chaperones forms the chromatin basic unit and serves to package the genome within the cell nucleus. The resulting chromatin organization, often referred to as the epigenome, contributes to a unique transcriptional program that defines cell identity. Importantly, during cellular life, substantial alterations in chromatin structure may arise due to cell stress, including DNA damage, which not only challenges the integrity of the genome but also threatens the epigenome. Considerable efforts have been made to decipher chromatin dynamics in response to genotoxic stress, and to assess how it affects both genome and epigenome stability. Here, we review recent advances in understanding the mechanisms of DNA damage-induced chromatin plasticity in mammalian cells. We focus specifically on the dynamics of histone H3 variants in response to UV irradiation, and highlight the role of their dedicated chaperones in restoring both chromatin structure and function. Finally, we discuss how, in addition to restoring chromatin integrity, the cellular networks that signal and repair DNA damage may also provide a window of opportunity for modulating the information conveyed by chromatin.
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Affiliation(s)
- Salomé Adam
- Institut Curie, Centre de Recherche, Paris, France; Centre National de la Recherche Scientifique, UMR3664, Paris, France; Equipe Labellisée Ligue Contre le Cancer, Paris, France; Institut de Formation Doctorale, University Pierre & Marie Curie, Paris, France; Sorbonne University, PSL*, Paris, France; Epigenetics and Cell Fate Centre, UMR7216, Centre National de la Recherche Scientifique/Paris Diderot University, Paris, France
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38
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Abstract
Nucleotide excision repair (NER) is the main pathway used by mammals to remove bulky DNA lesions such as those formed by UV light, environmental mutagens, and some cancer chemotherapeutic adducts from DNA. Deficiencies in NER are associated with the extremely skin cancer-prone inherited disorder xeroderma pigmentosum. Although the core NER reaction and the factors that execute it have been known for some years, recent studies have led to a much more detailed understanding of the NER mechanism, how NER operates in the context of chromatin, and how it is connected to other cellular processes such as DNA damage signaling and transcription. This review emphasizes biochemical, structural, cell biological, and genetic studies since 2005 that have shed light on many aspects of the NER pathway.
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Affiliation(s)
- Orlando D Schärer
- Department of Pharmacological Sciences and Department of Chemistry, Stony Brook University, Stony Brook, New York 11974-3400
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