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Araki R, Suga T, Hoki Y, Imadome K, Sunayama M, Kamimura S, Fujita M, Abe M. iPS cell generation-associated point mutations include many C > T substitutions via different cytosine modification mechanisms. Nat Commun 2024; 15:4946. [PMID: 38862540 PMCID: PMC11166658 DOI: 10.1038/s41467-024-49335-5] [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: 04/17/2023] [Accepted: 05/31/2024] [Indexed: 06/13/2024] Open
Abstract
Genomic aberrations are a critical impediment for the safe medical use of iPSCs and their origin and developmental mechanisms remain unknown. Here we find through WGS analysis of human and mouse iPSC lines that genomic mutations are de novo events and that, in addition to unmodified cytosine base prone to deamination, the DNA methylation sequence CpG represents a significant mutation-prone site. CGI and TSS regions show increased mutations in iPSCs and elevated mutations are observed in retrotransposons, especially in the AluY subfamily. Furthermore, increased cytosine to thymine mutations are observed in differentially methylated regions. These results indicate that in addition to deamination of cytosine, demethylation of methylated cytosine, which plays a central role in genome reprogramming, may act mutagenically during iPSC generation.
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Affiliation(s)
- Ryoko Araki
- Stem Cell Biology Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Chiba, Japan.
- Department of Radiation Regulatory Science Research, Institute for Radiological Science, National Institutes for Quantum Science and Technology, Chiba, Japan.
| | - Tomo Suga
- Stem Cell Biology Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Radiation Regulatory Science Research, Institute for Radiological Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Yuko Hoki
- Stem Cell Biology Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Radiation Regulatory Science Research, Institute for Radiological Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Kaori Imadome
- Stem Cell Biology Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Radiation Regulatory Science Research, Institute for Radiological Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Misato Sunayama
- Stem Cell Biology Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Radiation Regulatory Science Research, Institute for Radiological Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Satoshi Kamimura
- Stem Cell Biology Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Radiation Regulatory Science Research, Institute for Radiological Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Mayumi Fujita
- Stem Cell Biology Team, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Chiba, Japan
- Department of Radiation Regulatory Science Research, Institute for Radiological Science, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Masumi Abe
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba, Japan.
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2
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Crisalli AM, Chen YT, Cai A, Li D, Cho BP. Conformation-dependent lesion bypass of bulky arylamine-dG adducts generated from 2-nitrofluorene in epigenetic sequence contexts. Nucleic Acids Res 2023; 51:12043-12053. [PMID: 37953358 PMCID: PMC10711442 DOI: 10.1093/nar/gkad1038] [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: 08/05/2023] [Revised: 09/27/2023] [Accepted: 10/24/2023] [Indexed: 11/14/2023] Open
Abstract
Sequence context influences structural characteristics and repair of DNA adducts, but there is limited information on how epigenetic modulation affects conformational heterogeneity and bypass of DNA lesions. Lesions derived from the environmental pollutant 2-nitrofluorene have been extensively studied as chemical carcinogenesis models; they adopt a sequence-dependent mix of two significant conformers: major groove binding (B) and base-displaced stacked (S). We report a conformation-dependent bypass of the N-(2'-deoxyguanosin-8-yl)-7-fluoro-2-aminofluorene (dG-FAF) lesion in epigenetic sequence contexts (d[5'-CTTCTC#G*NCCTCATTC-3'], where C# is C or 5-methylcytosine (5mC), G* is G or G-FAF, and N is A, T, C or G). FAF-modified sequences with a 3' flanking pyrimidine were better bypassed when the 5' base was 5mC, whereas sequences with a 3' purine exhibited the opposite effect. The conformational basis behind these variations differed; for -CG*C- and -CG*T-, bypass appeared to be inversely correlated with population of the duplex-destabilizing S conformer. On the other hand, the connection between conformation and a decrease in bypass for flanking purines in the 5mC sequences relative to C was more complex. It could be related to the emergence of a disruptive non-S/B conformation. The present work provides novel conformational insight into how 5mC influences the bypass efficiency of bulky DNA damage.
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Affiliation(s)
- Alicia M Crisalli
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - Yi-Tzai Chen
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - Ang Cai
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - Deyu Li
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
| | - Bongsup P Cho
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881, USA
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3
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Pol β gap filling, DNA ligation and substrate-product channeling during base excision repair opposite oxidized 5-methylcytosine modifications. DNA Repair (Amst) 2020; 95:102945. [PMID: 32853828 DOI: 10.1016/j.dnarep.2020.102945] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/07/2020] [Accepted: 07/24/2020] [Indexed: 12/13/2022]
Abstract
DNA methylation on cytosine in CpG islands generates 5-methylcytosine (5mC), and further modification of 5mC can result in the oxidized variants 5-hydroxymethyl (5hmC), 5-formyl (5fC), and 5-carboxy (5caC). Base excision repair (BER) is crucial for both genome maintenance and active DNA demethylation of modified cytosine products and involves substrate-product channeling from nucleotide insertion by DNA polymerase (pol) β to the subsequent ligation step. Here, we report that, in contrast to the pol β mismatch insertion products (dCTP, dATP, and dTTP), the nicked products after pol β dGTP insertion can be ligated by DNA ligase I or DNA ligase III/XRCC1 complex when a 5mC oxidation modification is present opposite in the template position in vitro. A Pol β K280A mutation, which perturbates the stabilization of these base modifications within the active site, hinders the BER ligases. Moreover, the nicked repair intermediates that mimic pol β mismatch insertion products, i.e., with 3'-preinserted dGMP or dTMP opposite templating 5hmC, 5fC or 5caC, can be efficiently ligated, whereas preinserted 3'-dAMP or dCMP mismatches result in failed ligation reactions. These findings herein contribute to our understanding of the insertion tendencies of pol β opposite different cytosine base forms, the ligation properties of DNA ligase I and DNA ligase III/XRCC1 complex in the context of gapped and nicked damage-containing repair intermediates, and the efficiency and fidelity of substrate channeling during the final steps of BER in situations involving oxidative 5mC base modifications in the template strand.
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4
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Antibiotic Resistance and Epigenetics: More to It than Meets the Eye. Antimicrob Agents Chemother 2020; 64:AAC.02225-19. [PMID: 31740560 DOI: 10.1128/aac.02225-19] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The discovery of antibiotics in the last century is considered one of the most important achievements in the history of medicine. Antibiotic usage has significantly reduced morbidity and mortality associated with bacterial infections. However, inappropriate use of antibiotics has led to emergence of antibiotic resistance at an alarming rate. Antibiotic resistance is regarded as a major health care challenge of this century. Despite extensive research, well-documented biochemical mechanisms and genetic changes fail to fully explain mechanisms underlying antibiotic resistance. Several recent reports suggest a key role for epigenetics in the development of antibiotic resistance in bacteria. The intrinsic heterogeneity as well as transient nature of epigenetic inheritance provides a plausible backdrop for high-paced emergence of drug resistance in bacteria. The methylation of adenines and cytosines can influence mutation rates in bacterial genomes, thus modulating antibiotic susceptibility. In this review, we discuss a plethora of recently discovered epigenetic mechanisms and their emerging roles in antibiotic resistance. We also highlight specific epigenetic mechanisms that merit further investigation for their role in antibiotic resistance.
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Xiong J, Ye TT, Ma CJ, Cheng QY, Yuan BF, Feng YQ. N 6-Hydroxymethyladenine: a hydroxylation derivative of N6-methyladenine in genomic DNA of mammals. Nucleic Acids Res 2019; 47:1268-1277. [PMID: 30517733 PMCID: PMC6379677 DOI: 10.1093/nar/gky1218] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/04/2018] [Accepted: 11/22/2018] [Indexed: 12/19/2022] Open
Abstract
In addition to DNA cytosine methylation (5-methyl-2′-deoxycytidine, m5dC), DNA adenine methylation (N6-methyl-2′-deoxyadenosine, m6dA) is another DNA modification that has been discovered in eukaryotes. Recent studies demonstrated that the content and distribution of m6dA in genomic DNA of vertebrates and mammals exhibit dynamic regulation, indicating m6dA may function as a potential epigenetic mark in DNA of eukaryotes besides m5dC. Whether m6dA undergoes the further oxidation in a similar way to m5dC remains elusive. Here, we reported the existence of a new DNA modification, N6-hydroxymethyl-2′-deoxyadenosine (hm6dA), in genomic DNA of mammalian cells and tissues. We found that hm6dA can be formed from the hydroxylation of m6dA by the Fe2+- and 2-oxoglutarate-dependent ALKBH1 protein in genomic DNA of mammals. In addition, the content of hm6dA exhibited significant increase in lung carcinoma tissues. The increased expression of ALKBH1 in lung carcinoma tissues may contribute to the increase of hm6dA in DNA. Taken together, our study reported the existence and formation of hm6dA in genomic DNA of mammals.
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Affiliation(s)
- Jun Xiong
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Tian-Tian Ye
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Cheng-Jie Ma
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Qing-Yun Cheng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Bi-Feng Yuan
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
| | - Yu-Qi Feng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China
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6
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Biological Evaluation of DNA Biomarkers in a Chemically Defined and Site-Specific Manner. TOXICS 2019; 7:toxics7020036. [PMID: 31242562 PMCID: PMC6631660 DOI: 10.3390/toxics7020036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 02/06/2023]
Abstract
As described elsewhere in this Special Issue on biomarkers, much progress has been made in the detection of modified DNA within organisms at endogenous and exogenous levels of exposure to chemical species, including putative carcinogens and chemotherapeutic agents. Advances in the detection of damaged or unnatural bases have been able to provide correlations to support or refute hypotheses between the level of exposure to oxidative, alkylative, and other stresses, and the resulting DNA damage (lesion formation). However, such stresses can form a plethora of modified nucleobases, and it is therefore difficult to determine the individual contribution of a particular modification to alter a cell's genetic fate, as measured in the form of toxicity by stalled replication past the damage, by subsequent mutation, and by lesion repair. Chemical incorporation of a modification at a specific site within a vector (site-specific mutagenesis) has been a useful tool to deconvolute what types of damage quantified in biologically relevant systems may lead to toxicity and/or mutagenicity, thereby allowing researchers to focus on the most relevant biomarkers that may impact human health. Here, we will review a sampling of the DNA modifications that have been studied by shuttle vector techniques.
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Howard MJ, Foley KG, Shock DD, Batra VK, Wilson SH. Molecular basis for the faithful replication of 5-methylcytosine and its oxidized forms by DNA polymerase β. J Biol Chem 2019; 294:7194-7201. [PMID: 30885943 DOI: 10.1074/jbc.ra118.006809] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/13/2019] [Indexed: 01/10/2023] Open
Abstract
DNA methylation is an epigenetic mark that regulates gene expression in mammals. One method of methylation removal is through ten-eleven translocation-catalyzed oxidation and the base excision repair pathway. The iterative oxidation of 5-methylcytosine catalyzed by ten-eleven translocation enzymes produces three oxidized forms of cytosine: 5-hydroxmethylcytosine, 5-formylcytosine, and 5-carboxycytosine. The effect these modifications have on the efficiency and fidelity of the base excision repair pathway during the repair of opposing base damage, and in particular DNA polymerization, remains to be elucidated. Using kinetic assays, we show that the catalytic efficiency for the incorporation of dGTP catalyzed by human DNA polymerase β is not affected when 5-methylcytosine, 5-hydroxmethylcytosine, and 5-formylcytosine are in the DNA template. In contrast, the catalytic efficiency of dGTP insertion decreases ∼20-fold when 5-carboxycytosine is in the templating position, as compared with unmodified cytosine. However, DNA polymerase fidelity is unaltered when these modifications are in the templating position. Structural analysis reveals that the methyl, hydroxymethyl, and formyl modifications are easily accommodated within the polymerase active site. However, to accommodate the carboxyl modification, the phosphate backbone on the templating nucleotide shifts ∼2.5 Å to avoid a potential steric/repulsive clash. This altered conformation is stabilized by lysine 280, which makes a direct interaction with the carboxyl modification and the phosphate backbone of the templating strand. This work provides the molecular basis for the accommodation of epigenetic base modifications in a polymerase active site and suggests that these modifications are not mutagenically copied during base excision repair.
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Affiliation(s)
- Michael J Howard
- From the Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - K Grace Foley
- From the Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - David D Shock
- From the Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Vinod K Batra
- From the Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Samuel H Wilson
- From the Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
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8
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Tomkova M, Schuster-Böckler B. DNA Modifications: Naturally More Error Prone? Trends Genet 2018; 34:627-638. [PMID: 29853204 DOI: 10.1016/j.tig.2018.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/22/2018] [Accepted: 04/27/2018] [Indexed: 12/31/2022]
Abstract
Epigenetic DNA modifications are essential for normal cell function in vertebrates, but they can also be hotspots of mutagenesis. Methylcytosine in particular has long been known to be less stable than other nucleotides and spontaneously deaminates to thymine. Beyond this well-established phenomenon, however, the influence of epigenetic marks on mutagenesis has recently become an active field of investigation. In this review, we summarize current knowledge of the interactions between different DNA modifications and other mutagenic processes. External mutagens, such as UV light or smoking carcinogens, affect modified cytosines differently from unmodified ones, and modified cytosine can in some cases be protective rather than mutagenic. Notably, cell-intrinsic processes, such as DNA replication, also appear to influence the mutagenesis of modified cytosines. Altogether, evidence is accumulating to show that epigenetic changes have a profound influence on tissue-specific mutation accumulation.
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Affiliation(s)
- Marketa Tomkova
- Ludwig Cancer Research Oxford, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Benjamin Schuster-Böckler
- Ludwig Cancer Research Oxford, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK.
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9
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Affiliation(s)
- Yang Yu
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Yuxiang Cui
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
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10
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Yu Y, Cui Y, Niedernhofer LJ, Wang Y. Occurrence, Biological Consequences, and Human Health Relevance of Oxidative Stress-Induced DNA Damage. Chem Res Toxicol 2016; 29:2008-2039. [PMID: 27989142 DOI: 10.1021/acs.chemrestox.6b00265] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A variety of endogenous and exogenous agents can induce DNA damage and lead to genomic instability. Reactive oxygen species (ROS), an important class of DNA damaging agents, are constantly generated in cells as a consequence of endogenous metabolism, infection/inflammation, and/or exposure to environmental toxicants. A wide array of DNA lesions can be induced by ROS directly, including single-nucleobase lesions, tandem lesions, and hypochlorous acid (HOCl)/hypobromous acid (HOBr)-derived DNA adducts. ROS can also lead to lipid peroxidation, whose byproducts can also react with DNA to produce exocyclic DNA lesions. A combination of bioanalytical chemistry, synthetic organic chemistry, and molecular biology approaches have provided significant insights into the occurrence, repair, and biological consequences of oxidatively induced DNA lesions. The involvement of these lesions in the etiology of human diseases and aging was also investigated in the past several decades, suggesting that the oxidatively induced DNA adducts, especially bulky DNA lesions, may serve as biomarkers for exploring the role of oxidative stress in human diseases. The continuing development and improvement of LC-MS/MS coupled with the stable isotope-dilution method for DNA adduct quantification will further promote research about the clinical implications and diagnostic applications of oxidatively induced DNA adducts.
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Affiliation(s)
| | | | - Laura J Niedernhofer
- Department of Metabolism and Aging, The Scripps Research Institute Florida , Jupiter, Florida 33458, United States
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11
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Mahfoudhi E, Talhaoui I, Cabagnols X, Della Valle V, Secardin L, Rameau P, Bernard OA, Ishchenko AA, Abbes S, Vainchenker W, Saparbaev M, Plo I. TET2-mediated 5-hydroxymethylcytosine induces genetic instability and mutagenesis. DNA Repair (Amst) 2016; 43:78-88. [DOI: 10.1016/j.dnarep.2016.05.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/28/2016] [Accepted: 05/23/2016] [Indexed: 02/04/2023]
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12
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Intrinsic mutagenic properties of 5-chlorocytosine: A mechanistic connection between chronic inflammation and cancer. Proc Natl Acad Sci U S A 2015; 112:E4571-80. [PMID: 26243878 DOI: 10.1073/pnas.1507709112] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
During chronic inflammation, neutrophil-secreted hypochlorous acid can damage nearby cells inducing the genomic accumulation of 5-chlorocytosine (5ClC), a known inflammation biomarker. Although 5ClC has been shown to promote epigenetic changes, it has been unknown heretofore if 5ClC directly perpetrates a mutagenic outcome within the cell. The present work shows that 5ClC is intrinsically mutagenic, both in vitro and, at a level of a single molecule per cell, in vivo. Using biochemical and genetic approaches, we have quantified the mutagenic and toxic properties of 5ClC, showing that this lesion caused C→T transitions at frequencies ranging from 3-9% depending on the polymerase traversing the lesion. X-ray crystallographic studies provided a molecular basis for the mutagenicity of 5ClC; a snapshot of human polymerase β replicating across a primed 5ClC-containing template uncovered 5ClC engaged in a nascent base pair with an incoming dATP analog. Accommodation of the chlorine substituent in the template major groove enabled a unique interaction between 5ClC and the incoming dATP, which would facilitate mutagenic lesion bypass. The type of mutation induced by 5ClC, the C→T transition, has been previously shown to occur in substantial amounts both in tissues under inflammatory stress and in the genomes of many inflammation-associated cancers. In fact, many sequence-specific mutational signatures uncovered in sequenced cancer genomes feature C→T mutations. Therefore, the mutagenic ability of 5ClC documented in the present study may constitute a direct functional link between chronic inflammation and the genetic changes that enable and promote malignant transformation.
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13
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Chang SC, Fedeles BI, Wu J, Delaney JC, Li D, Zhao L, Christov PP, Yau E, Singh V, Jost M, Drennan CL, Marnett LJ, Rizzo CJ, Levine SS, Guengerich FP, Essigmann JM. Next-generation sequencing reveals the biological significance of the N(2),3-ethenoguanine lesion in vivo. Nucleic Acids Res 2015; 43:5489-500. [PMID: 25837992 PMCID: PMC4477646 DOI: 10.1093/nar/gkv243] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 12/20/2022] Open
Abstract
Etheno DNA adducts are a prevalent type of DNA damage caused by vinyl chloride (VC) exposure and oxidative stress. Etheno adducts are mutagenic and may contribute to the initiation of several pathologies; thus, elucidating the pathways by which they induce cellular transformation is critical. Although N(2),3-ethenoguanine (N(2),3-εG) is the most abundant etheno adduct, its biological consequences have not been well characterized in cells due to its labile glycosidic bond. Here, a stabilized 2'-fluoro-2'-deoxyribose analog of N(2),3-εG was used to quantify directly its genotoxicity and mutagenicity. A multiplex method involving next-generation sequencing enabled a large-scale in vivo analysis, in which both N(2),3-εG and its isomer 1,N(2)-ethenoguanine (1,N(2)-εG) were evaluated in various repair and replication backgrounds. We found that N(2),3-εG potently induces G to A transitions, the same mutation previously observed in VC-associated tumors. By contrast, 1,N(2)-εG induces various substitutions and frameshifts. We also found that N(2),3-εG is the only etheno lesion that cannot be repaired by AlkB, which partially explains its persistence. Both εG lesions are strong replication blocks and DinB, a translesion polymerase, facilitates the mutagenic bypass of both lesions. Collectively, our results indicate that N(2),3-εG is a biologically important lesion and may have a functional role in VC-induced or inflammation-driven carcinogenesis.
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Affiliation(s)
- Shiou-chi Chang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Bogdan I Fedeles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Jie Wu
- BioMicro Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - James C Delaney
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Deyu Li
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Linlin Zhao
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, United States Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232, United States
| | - Plamen P Christov
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, United States Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232, United States Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States
| | - Emily Yau
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Vipender Singh
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Marco Jost
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Catherine L Drennan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Lawrence J Marnett
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, United States Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232, United States Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232, United States
| | - Carmelo J Rizzo
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, United States Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232, United States Department of Chemistry, Vanderbilt University, Nashville, TN 37232, United States Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232, United States
| | - Stuart S Levine
- BioMicro Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, United States Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232, United States Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232, United States
| | - John M Essigmann
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
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14
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Tang Y, Zheng SJ, Qi CB, Feng YQ, Yuan BF. Sensitive and Simultaneous Determination of 5-Methylcytosine and Its Oxidation Products in Genomic DNA by Chemical Derivatization Coupled with Liquid Chromatography-Tandem Mass Spectrometry Analysis. Anal Chem 2015; 87:3445-52. [DOI: 10.1021/ac504786r] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Yang Tang
- Key
Laboratory of Analytical Chemistry for Biology and Medicine (Ministry
of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
- Guangxi Zhuang Autonomous Region Center for Disease Prevention and Control, Nanning, Guangxi 530028, P.R. China
| | - Shu-Jian Zheng
- Key
Laboratory of Analytical Chemistry for Biology and Medicine (Ministry
of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Chu-Bo Qi
- Key
Laboratory of Analytical Chemistry for Biology and Medicine (Ministry
of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
- Department
of Pathology, Hubei Cancer Hospital, Wuhan, Hubei 430079, P.R. China
| | - Yu-Qi Feng
- Key
Laboratory of Analytical Chemistry for Biology and Medicine (Ministry
of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Bi-Feng Yuan
- Key
Laboratory of Analytical Chemistry for Biology and Medicine (Ministry
of Education), Department of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
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15
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Huang W, Xiong J, Yang Y, Liu SM, Yuan BF, Feng YQ. Determination of DNA adenine methylation in genomes of mammals and plants by liquid chromatography/mass spectrometry. RSC Adv 2015. [DOI: 10.1039/c5ra05307b] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Determination of DNA adenine methylation in genomes of mammals and plants.
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Affiliation(s)
- Wei Huang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)
- Department of Chemistry
- Wuhan University
- Wuhan 430072
- P.R. China
| | - Jun Xiong
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)
- Department of Chemistry
- Wuhan University
- Wuhan 430072
- P.R. China
| | - Ying Yang
- Center for Gene Diagnosis
- Zhongnan Hospital of Wuhan University
- Wuhan
- P.R. China
| | - Song-Mei Liu
- Center for Gene Diagnosis
- Zhongnan Hospital of Wuhan University
- Wuhan
- P.R. China
| | - Bi-Feng Yuan
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)
- Department of Chemistry
- Wuhan University
- Wuhan 430072
- P.R. China
| | - Yu-Qi Feng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education)
- Department of Chemistry
- Wuhan University
- Wuhan 430072
- P.R. China
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16
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Effects of Tet-mediated oxidation products of 5-methylcytosine on DNA transcription in vitro and in mammalian cells. Sci Rep 2014; 4:7052. [PMID: 25394478 PMCID: PMC4231326 DOI: 10.1038/srep07052] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 10/24/2014] [Indexed: 12/21/2022] Open
Abstract
5-methylcytosine (5-mC) is a well-characterized epigenetic regulator in mammals. Recent studies showed that Ten-eleven translocation (Tet) proteins can catalyze the stepwise oxidation of 5-mC to produce 5-hydroxymethylcytosine (5-HmC), 5-formylcytosine (5-FoC) and 5-carboxylcytosine (5-CaC). The exciting discovery of these novel cytosine modifications has stimulated substantial research interests about their roles in epigenetic regulation. Here we systematically examined the effects of the oxidized 5-mC derivatives on the efficiency and fidelity of DNA transcription using a recently developed competitive transcription and adduct bypass assay. Our results showed that, when located on the transcribed strand, 5-FoC and 5-CaC exhibited marginal mutagenic and modest inhibitory effects on DNA transcription mediated by single-subunit T7 RNA polymerase or multi-subunit human RNA polymerase II in vitro and in human cells. 5-HmC displayed relatively milder blocking effects on transcription, and no mutant transcript could be detectable for 5-HmC in vitro or in cells. The lack of considerable mutagenic effects of the oxidized 5-mC derivatives on transcription was in agreement with their functions in epigenetic regulation. The modest blocking effects on transcription suggested that 5-FoC and 5-CaC may function in transcriptional regulation. These findings provided new evidence for the potential functional interplay between cytosine methylation status and transcription.
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17
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Xing XW, Tang F, Wu J, Chu JM, Feng YQ, Zhou X, Yuan BF. Sensitive Detection of DNA Methyltransferase Activity Based on Exonuclease-Mediated Target Recycling. Anal Chem 2014; 86:11269-74. [DOI: 10.1021/ac502845b] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Xi-Wen Xing
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Feng Tang
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Jun Wu
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Jie-Mei Chu
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Yu-Qi Feng
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Xiang Zhou
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Bi-Feng Yuan
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan, Hubei 430072, P.R. China
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18
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Supek F, Lehner B, Hajkova P, Warnecke T. Hydroxymethylated cytosines are associated with elevated C to G transversion rates. PLoS Genet 2014; 10:e1004585. [PMID: 25211471 PMCID: PMC4161303 DOI: 10.1371/journal.pgen.1004585] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/07/2014] [Indexed: 11/23/2022] Open
Abstract
It has long been known that methylated cytosines deaminate at higher rates than unmodified cytosines and constitute mutational hotspots in mammalian genomes. The repertoire of naturally occurring cytosine modifications, however, extends beyond 5-methylcytosine to include its oxidation derivatives, notably 5-hydroxymethylcytosine. The effects of these modifications on sequence evolution are unknown. Here, we combine base-resolution maps of methyl- and hydroxymethylcytosine in human and mouse with population genomic, divergence and somatic mutation data to show that hydroxymethylated and methylated cytosines show distinct patterns of variation and evolution. Surprisingly, hydroxymethylated sites are consistently associated with elevated C to G transversion rates at the level of segregating polymorphisms, fixed substitutions, and somatic mutations in tumors. Controlling for multiple potential confounders, we find derived C to G SNPs to be 1.43-fold (1.22-fold) more common at hydroxymethylated sites compared to methylated sites in human (mouse). Increased C to G rates are evident across diverse functional and sequence contexts and, in cancer genomes, correlate with the expression of Tet enzymes and specific components of the mismatch repair pathway (MSH2, MSH6, and MBD4). Based on these and other observations we suggest that hydroxymethylation is associated with a distinct mutational burden and that the mismatch repair pathway is implicated in causing elevated transversion rates at hydroxymethylated cytosines. Most cytosines that occur in a CpG context in mammalian genomes are methylated. Methylation has important functional consequences in the cell but also affects genome evolution. Notably, methylated cytosines are prone to deaminate and constitute mutational hotspots in mammalian genomes. Recently, a series of other modifications, derived from the oxidation of methylated cytosines, was shown to exist in various mammalian cell types including embryonic stem cells. The most abundant of these modifications is 5-hydroxymethylcytosine. In this work, we ask whether methylated and hydroxymethylated cytosines are subject to the same mutational biases or lead to distinct patterns of genome evolution. To do so, we examine differences between individuals, between species, and between normal and cancer tissues alongside high-resolution maps of DNA methylation and hydroxymethylation in the human and mouse genomes. Unexpectedly, we find that hydroxymethylated cytosines are associated with more cytosine to guanine changes in both human and mouse populations, in closely related species, and in the context of somatic evolution in tumors. Based on multiple lines of evidence, we suggest that the different patterns of sequence evolution at methylated and hydroxymethylated sites are owing to differences in how these sites are handled by the DNA repair machinery.
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Affiliation(s)
- Fran Supek
- EMBL-CRG Systems Biology Unit, Centre for Genomic Regulation (CRG), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Division of Electronics, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Ben Lehner
- EMBL-CRG Systems Biology Unit, Centre for Genomic Regulation (CRG), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, Centre for Genomic Regulation (CRG) and UPF, Barcelona, Spain
| | - Petra Hajkova
- Reprogramming and Chromatin Group, MRC Clinical Sciences Centre, Imperial College, Hammersmith Campus, London, United Kingdom
| | - Tobias Warnecke
- Molecular Systems Group, MRC Clinical Sciences Centre, Imperial College, Hammersmith Campus, London, United Kingdom
- * E-mail:
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19
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Ji D, You C, Wang P, Wang Y. Effects of tet-induced oxidation products of 5-methylcytosine on DNA replication in mammalian cells. Chem Res Toxicol 2014; 27:1304-9. [PMID: 24979327 PMCID: PMC4216192 DOI: 10.1021/tx500169u] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
Recently 5-hydroxymethyl-2′-deoxycytidine
(5hmdC), 5-formyl-2′-deoxycytidine
(5fdC), and 5-carboxyl-2′-deoxycytidine (5cadC) were discovered
in mammalian DNA as oxidation products of 5-methyl-2′-deoxycytidine
(5mdC) induced by the ten-eleven translocation family of enzymes.
These oxidized derivatives of 5mdC may not only act as intermediates
of active cytosine demethylation in mammals but also serve as epigenetic
marks on their own. It remains unclear how 5hmdC, 5fdC, and 5cadC
affect DNA replication in mammalian cells. Here, we examined the effects
of the three modified nucleosides on the efficiency and accuracy of
DNA replication in HEK293T human kidney epithelial cells. Our results
demonstrated that a single, site-specifically incorporated 5fdC or
5cadC conferred modest drops, by approximately 30%, in replication
bypass efficiency without inducing detectable mutations in human cells,
whereas replicative bypass of 5hmdC is both accurate and efficient.
The lack of pronounced perturbation of these oxidized 5mdC derivatives
on DNA replication is consistent with their roles in epigenetic regulation
of gene expression.
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Affiliation(s)
- Debin Ji
- Department of Chemistry, University of California , Riverside, California 92521, United States
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20
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Tang Y, Xiong J, Jiang HP, Zheng SJ, Feng YQ, Yuan BF. Determination of Oxidation Products of 5-Methylcytosine in Plants by Chemical Derivatization Coupled with Liquid Chromatography/Tandem Mass Spectrometry Analysis. Anal Chem 2014; 86:7764-72. [DOI: 10.1021/ac5016886] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Yang Tang
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Jun Xiong
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Han-Peng Jiang
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Shu-Jian Zheng
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Yu-Qi Feng
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
| | - Bi-Feng Yuan
- Key Laboratory of Analytical
Chemistry for Biology and Medicine (Ministry of Education), Department
of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
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21
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Shibutani T, Ito S, Toda M, Kanao R, Collins LB, Shibata M, Urabe M, Koseki H, Masuda Y, Swenberg JA, Masutani C, Hanaoka F, Iwai S, Kuraoka I. Guanine- 5-carboxylcytosine base pairs mimic mismatches during DNA replication. Sci Rep 2014; 4:5220. [PMID: 24910358 PMCID: PMC4048885 DOI: 10.1038/srep05220] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 05/19/2014] [Indexed: 11/09/2022] Open
Abstract
The genetic information encoded in genomes must be faithfully replicated and transmitted to daughter cells. The recent discovery of consecutive DNA conversions by TET family proteins of 5-methylcytosine into 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine (5caC) suggests these modified cytosines act as DNA lesions, which could threaten genome integrity. Here, we have shown that although 5caC pairs with guanine during DNA replication in vitro, G·5caC pairs stimulated DNA polymerase exonuclease activity and were recognized by the mismatch repair (MMR) proteins. Knockdown of thymine DNA glycosylase increased 5caC in genome, affected cell proliferation via MMR, indicating MMR is a novel reader for 5caC. These results suggest the epigenetic modification products of 5caC behave as DNA lesions.
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Affiliation(s)
- Toshihiro Shibutani
- Graduate School of Engineering Science, Osaka University Graduate School of Engineering Science, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 Japan
| | - Shinsuke Ito
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Mariko Toda
- Graduate School of Engineering Science, Osaka University Graduate School of Engineering Science, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 Japan
| | - Rie Kanao
- Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Leonard B Collins
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Marika Shibata
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Miho Urabe
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Yuji Masuda
- 1] Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan [2] Department of Toxicogenomics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
| | - James A Swenberg
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Chikahide Masutani
- Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Fumio Hanaoka
- Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Shigenori Iwai
- Graduate School of Engineering Science, Osaka University Graduate School of Engineering Science, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 Japan
| | - Isao Kuraoka
- Graduate School of Engineering Science, Osaka University Graduate School of Engineering Science, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 Japan
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23
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Abstract
Epigenetics has undergone an explosion in the past decade. DNA methylation, consisting of the addition of a methyl group at the fifth position of cytosine (5-methylcytosine, 5-mC) in a CpG dinucleotide, is a well-recognized epigenetic mark with important functions in cellular development and pathogenesis. Numerous studies have focused on the characterization of DNA methylation marks associated with disease development as they may serve as useful biomarkers for diagnosis, prognosis, and prediction of response to therapy. Recently, novel cytosine modifications with potential regulatory roles such as 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and 5-carboxylcytosine (5-caC) have been discovered. Study of the functions of 5-mC and its oxidation derivatives promotes the understanding of the mechanism underlying association of epigenetic modifications with disease biology. In this respect, much has been accomplished in the development of methods for the discovery, detection, and location analysis of 5-mC and its oxidation derivatives. In this review, we focus on the recent advances for the global detection and location study of 5-mC and its oxidation derivatives 5-hmC, 5-foC, and 5-caC.
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