1
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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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2
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Li J, Hu Z, Liu D, Wang P. Mass spectrometry-based assays for assessing replicative bypass and repair of DNA alkylation in cells. RSC Adv 2023; 13:15490-15497. [PMID: 37223415 PMCID: PMC10201546 DOI: 10.1039/d2ra08340j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 05/15/2023] [Indexed: 05/25/2023] Open
Abstract
Endogenous metabolism and environmental exposure can give rise to DNA alkylation, which can elicit deleterious biological consequences. In the search for reliable and quantitative analytical methods to elucidate the impact of DNA alkylation on the flow of genetic information, mass spectrometry (MS) has attracted increasing attention, owing to its unambiguous determination of molecular mass. The MS-based assays obviate conventional colony-picking methods and Sanger sequencing procedures, and retained the high sensitivity of postlabeling methods. With the help of the CRISPR/Cas9 gene editing method, MS-based assays showed high potential in studying individual functions of repair proteins and translesion synthesis (TLS) polymerases in DNA replication. In this mini-review, we have summarized the development of MS-based competitive and replicative adduct bypass (CRAB) assays and their recent applications in assessing the impact of alkylation on DNA replication. With further development of MS instruments for high resolving power and high throughput, these assays should be generally applicable and efficient in quantitative measurement of the biological consequences and repair of other DNA lesions.
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Affiliation(s)
- Jiaxian Li
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
| | - Zhihai Hu
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
| | - Dandan Liu
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
| | - Pengcheng Wang
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
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3
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Goyal K, Goel H, Baranwal P, Dixit A, Khan F, Jha NK, Kesari KK, Pandey P, Pandey A, Benjamin M, Maurya A, Yadav V, Sinh RS, Tanwar P, Upadhyay TK, Mittan S. Unravelling the molecular mechanism of mutagenic factors impacting human health. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:61993-62013. [PMID: 34410595 DOI: 10.1007/s11356-021-15442-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 07/09/2021] [Indexed: 06/13/2023]
Abstract
Environmental mutagens are chemical and physical substances in the environment that has a potential to induce a wide range of mutations and generate multiple physiological, biochemical, and genetic modifications in humans. Most mutagens are having genotoxic effects on the following generation through germ cells. The influence of germinal mutations on health will be determined by their frequency, nature, and the mechanisms that keep a specific mutation in the population. Early prenatal lethal mutations have less public health consequences than genetic illnesses linked with long-term medical and social difficulties. Physical and chemical mutagens are common mutagens found in the environment. These two environmental mutagens have been associated with multiple neurological disorders and carcinogenesis in humans. Thus in this study, we aim to unravel the molecular mechanism of physical mutagens (UV rays, X-rays, gamma rays), chemical mutagens (dimethyl sulfate (DMS), bisphenol A (BPA), polycyclic aromatic hydrocarbons (PAHs), 5-chlorocytosine (5ClC)), and several heavy metals (Ar, Pb, Al, Hg, Cd, Cr) implicated in DNA damage, carcinogenesis, chromosomal abnormalities, and oxidative stress which leads to multiple disorders and impacting human health. Biological tests for mutagen detection are crucial; therefore, we also discuss several approaches (Ames test and Mutatox test) to estimate mutagenic factors in the environment. The potential risks of environmental mutagens impacting humans require a deeper basic knowledge of human genetics as well as ongoing research on humans, animals, and their tissues and fluids.
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Affiliation(s)
- Keshav Goyal
- Department of Microbiology, Ram Lal Anand College, University of Delhi, New Delhi, India
| | - Harsh Goel
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Pritika Baranwal
- Department of Microbiology, Ram Lal Anand College, University of Delhi, New Delhi, India
| | - Aman Dixit
- Department of Microbiology, Ram Lal Anand College, University of Delhi, New Delhi, India
| | - Fahad Khan
- Department of Biotechnology, Noida Institute of Engineering & Technology, 19, Knowledge Park-II, Institutional Area, Greater Noida, 201306, India
| | - Niraj Kumar Jha
- Department of Biotechnology, School of Engineering and Technology (SET), Sharda University, Greater Noida, India
| | | | - Pratibha Pandey
- Department of Biotechnology, Noida Institute of Engineering & Technology, 19, Knowledge Park-II, Institutional Area, Greater Noida, 201306, India
| | - Avanish Pandey
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Mercilena Benjamin
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Ankit Maurya
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Vandana Yadav
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
| | - Rana Suryauday Sinh
- Department of Microbiology and Biotechnology Centre, Maharaja Sayajirao University, Baroda, India
| | - Pranay Tanwar
- Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India
| | - Tarun Kumar Upadhyay
- Department of Biotechnology, Parul Institute of Applied Sciences & Centre of Research for Development, Parul University, Vadodara, Gujarat, India.
| | - Sandeep Mittan
- Department of Cardiology, Ichan School of Medicine, Mount Sinai Hospital, 1 Gustave L. Levy Place, New York, NY, USA
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4
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Aralov AV, Gubina N, Cabrero C, Tsvetkov VB, Turaev AV, Fedeles BI, Croy RG, Isaakova EA, Melnik D, Dukova S, Ryazantsev DY, Khrulev AA, Varizhuk AM, González C, Zatsepin TS, Essigmann JM. 7,8-Dihydro-8-oxo-1,N6-ethenoadenine: an exclusively Hoogsteen-paired thymine mimic in DNA that induces A→T transversions in Escherichia coli. Nucleic Acids Res 2022; 50:3056-3069. [PMID: 35234900 PMCID: PMC8989528 DOI: 10.1093/nar/gkac148] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 02/09/2022] [Accepted: 02/25/2022] [Indexed: 12/15/2022] Open
Abstract
This work investigated the structural and biological properties of DNA containing 7,8-dihydro-8-oxo-1,N6-ethenoadenine (oxo-ϵA), a non-natural synthetic base that combines structural features of two naturally occurring DNA lesions (7,8-dihydro-8-oxoadenine and 1,N6-ethenoadenine). UV-, CD-, NMR spectroscopies and molecular modeling of DNA duplexes revealed that oxo-ϵA adopts the non-canonical syn conformation (χ = 65º) and fits very well among surrounding residues without inducing major distortions in local helical architecture. The adduct remarkably mimics the natural base thymine. When considered as an adenine-derived DNA lesion, oxo-ϵA was >99% mutagenic in living cells, causing predominantly A→T transversion mutations in Escherichia coli. The adduct in a single-stranded vector was not repaired by base excision repair enzymes (MutM and MutY glycosylases) or the AlkB dioxygenase and did not detectably affect the efficacy of DNA replication in vivo. When the biological and structural data are viewed together, it is likely that the nearly exclusive syn conformation and thymine mimicry of oxo-ϵA defines the selectivity of base pairing in vitro and in vivo, resulting in lesion pairing with A during replication. The base pairing properties of oxo-ϵA, its strong fluorescence and its invisibility to enzymatic repair systems in vivo are features that are sought in novel DNA-based probes and modulators of gene expression.
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Affiliation(s)
- Andrey V Aralov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
| | - Nina Gubina
- Department of Biological Engineering, Department of Chemistry and Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Institute of Theoretical and Experimental Biophysics RAS, Pushchino 142290, Russia
| | - Cristina Cabrero
- Instituto de Química-Física Rocasolano (IQFR-CSIC), Madrid 28006, Spain
| | - Vladimir B Tsvetkov
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia.,World-Class Research Center "Digital biodesign and personalized healthcare", Sechenov First Moscow State Medical University, Moscow 119146, Russia
| | - Anton V Turaev
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia
| | - Bogdan I Fedeles
- Department of Biological Engineering, Department of Chemistry and Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert G Croy
- Department of Biological Engineering, Department of Chemistry and Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ekaterina A Isaakova
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia
| | - Denis Melnik
- Center for Life Sciences, Skolkovo Institute of Science and Technology, Moscow 143026, Russia
| | - Svetlana Dukova
- Center for Life Sciences, Skolkovo Institute of Science and Technology, Moscow 143026, Russia
| | - Dmitriy Y Ryazantsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
| | - Alexei A Khrulev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
| | - Anna M Varizhuk
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Carlos González
- Instituto de Química-Física Rocasolano (IQFR-CSIC), Madrid 28006, Spain
| | - Timofei S Zatsepin
- Center for Life Sciences, Skolkovo Institute of Science and Technology, Moscow 143026, Russia.,Chemistry Department, Lomonosov Moscow State University, Moscow 119992, Russia
| | - John M Essigmann
- Department of Biological Engineering, Department of Chemistry and Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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5
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Abstract
Genomic DNA is chemically reactive and therefore susceptible to damage by many exogenous and endogenous sources. Lesions produced from these damaging events can have various mutagenic and genotoxic consequences. This Perspective follows the journey of one particular lesion, 1,N6-ethenoadenine (εA), from its formation to replication and repair, and its role in cancerous tissues and inflammatory diseases. εA is generated by the reaction of adenine (A) with vinyl chloride or lipid peroxidation products. We present the miscoding properties of εA with an emphasis on how bacterial and mammalian cells can process lesions differently, leading to varied mutational spectra. But with information from these assays, we can better understand how the miscoding properties of εA lead to biological consequences and how genomic stability can be maintained via DNA repair mechanisms. We discuss how base excision repair (BER) and direct reversal repair (DRR) can minimize the biological consequences of εA lesions. Kinetic parameters of glycosylases and AlkB family enzymes are described, along with a discussion of the relative contributions of the BER and DRR pathways in the repair of εA. Because eukaryotic DNA is packaged in chromatin, we also discuss the impact of this packaging on BER and DRR, specifically in regards to repair of εA. Studying DNA lesions like εA in this context, from origin to biological implications, can provide crucial information to better understand prevention of mutagenesis and cancer.
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Affiliation(s)
- Katelyn L Rioux
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Sarah Delaney
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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6
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Wu J, Yuan J, Price NE, Wang Y. Ada protein- and sequence context-dependent mutagenesis of alkyl phosphotriester lesions in Escherichia coli cells. J Biol Chem 2020; 295:8775-8783. [PMID: 32381504 DOI: 10.1074/jbc.ra120.013657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 05/01/2020] [Indexed: 11/06/2022] Open
Abstract
Alkyl phosphotriester (alkyl-PTE) lesions are frequently induced in DNA and are resistant to repair. Here, we synthesized and characterized methyl (Me)- and n-butyl (nBu)-PTEs in two diastereomeric configurations (S p and R p) at six different flanking dinucleotide sites, i.e. XT and TX (X = A, C, or G), and assessed how these lesions impact DNA replication in Escherichia coli cells. When single-stranded vectors contained an S p-Me-PTE in the sequence contexts of 5'-AT-3', 5'-CT-3', or 5'-GT-3', DNA replication was highly efficient and the replication products for all three sequence contexts contained 85-90% AT and 5-10% TG. Thus, the replication outcome was largely independent of the identity of the 5' nucleotide adjacent to an S p-Me-PTE. Furthermore, replication across these lesions was not dependent on the activities of DNA polymerases II, IV, or V; Ada, a protein involved in adaptive response and repair of S p-Me-PTE in E. coli, however, was essential for the generation of the mutagenic products. Additionally, the R p diastereomer of Me-PTEs at XT sites and both diastereomers of Me-PTEs at TX sites exhibited error-free replication bypass. Moreover, S p-nBu-PTEs at XT sites did not strongly impede DNA replication, and other nBu-PTEs displayed moderate blockage effects, with none of them being mutagenic. Taken together, these findings provide in-depth understanding of how alkyl-PTE lesions are recognized by the DNA replication machinery in prokaryotic cells and reveal that Ada contributes to mutagenesis of S p-Me-PTEs in E. coli.
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Affiliation(s)
- Jiabin Wu
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA
| | - Jun Yuan
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA
| | - Nathan E Price
- Department of Chemistry, University of California, Riverside, California, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA; Department of Chemistry, University of California, Riverside, California, USA.
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7
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Abstract
Genome integrity is constantly challenged by endogenous or exogenous genotoxic agents, which can give rise to various DNA adducts. After metabolic activation, tobacco-specific nitrosamines N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) can lead to pyridyloxobutylphosphotriesters (POB-PTEs) in DNA. Here, we synthesized oligodeoxyribonucleotides containing a site-specifically inserted SP- or RP-POB-PTE flanked by two thymidines, and we examined the impact that these lesions have on DNA replication in Escherichia coli cells. We found that these two lesions are not strong impediments to DNA replication, and their replicative bypass is not modulated by genetic depletion of the three SOS-induced DNA polymerases or Ada protein. In addition, neither SP- nor RP-POB-PTEs was mutagenic in E. coli cells. Together, our study unveiled, for the first time, the influence of tobacco-specific nitrosamine-induced POB-PTE lesions on DNA replication in vivo.
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8
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Wu J, Wang P, Wang Y. Cytotoxic and mutagenic properties of alkyl phosphotriester lesions in Escherichia coli cells. Nucleic Acids Res 2019. [PMID: 29514270 PMCID: PMC5934668 DOI: 10.1093/nar/gky140] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Exposure to many endogenous and exogenous agents can give rise to DNA alkylation, which constitutes a major type of DNA damage. Among the DNA alkylation products, alkyl phosphotriesters have relatively high frequencies of occurrence and are resistant to repair in mammalian tissues. However, little is known about how these lesions affect the efficiency and fidelity of DNA replication in cells or how the replicative bypass of these lesions is modulated by translesion synthesis DNA polymerases. In this study, we synthesized oligodeoxyribonucleotides containing four pairs (Sp and Rp) of alkyl phosphotriester lesions at a defined site, and examined how these lesions are recognized by DNA replication machinery in Escherichia coli cells. We found that the Sp diastereomer of the alkyl phosphotriester lesions could be efficiently bypassed, whereas the Rp counterparts moderately blocked DNA replication. Moreover, the Sp-methyl phosphotriester induced TT→GT and TT→GC mutations at the flanking TT dinucleotide site, and the induction of these mutations required Ada protein, which is known to remove efficiently the methyl group from the Sp-methyl phosphotriester. Together, our study provided a comprehensive understanding about the recognition of alkyl phosphotriester lesions by DNA replication machinery in cells, and revealed for the first time the Ada-dependent induction of mutations at the Sp-methyl phosphotriester site.
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Affiliation(s)
- Jiabin Wu
- Environmental Toxicology Graduate Program and Department of Chemistry, University of California Riverside, Riverside, CA 92521-0403, USA
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program and Department of Chemistry, University of California Riverside, Riverside, CA 92521-0403, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program and Department of Chemistry, University of California Riverside, Riverside, CA 92521-0403, USA
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9
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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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10
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Wang P, Leng J, Wang Y. DNA replication studies of N-nitroso compound-induced O6-alkyl-2'-deoxyguanosine lesions in Escherichia coli. J Biol Chem 2019; 294:3899-3908. [PMID: 30655287 PMCID: PMC6422096 DOI: 10.1074/jbc.ra118.007358] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 01/16/2019] [Indexed: 12/30/2022] Open
Abstract
N-Nitroso compounds (NOCs) are common DNA-alkylating agents, are abundantly present in food and tobacco, and can also be generated endogenously. Metabolic activation of some NOCs can give rise to carboxymethylation and pyridyloxobutylation/pyridylhydroxybutylation of DNA, which are known to be carcinogenic and can lead to gastrointestinal and lung cancer, respectively. Herein, using the competitive replication and adduct bypass (CRAB) assay, along with MS- and NMR-based approaches, we assessed the cytotoxic and mutagenic properties of three O6-alkyl-2'-deoxyguanosine (O6-alkyl-dG) adducts, i.e. O6-pyridyloxobutyl-dG (O6-POB-dG) and O6-pyridylhydroxybutyl-dG (O6-PHB-dG), derived from tobacco-specific nitrosamines, and O6-carboxymethyl-dG (O6-CM-dG), induced by endogenous N-nitroso compounds. We also investigated two neutral analogs of O6-CM-dG, i.e. O6-aminocarbonylmethyl-dG (O6-ACM-dG) and O6-hydroxyethyl-dG (O6-HOEt-dG). We found that, in Escherichia coli cells, these lesions mildly (O6-POB-dG), moderately (O6-PHB-dG), or strongly (O6-CM-dG, O6-ACM-dG, and O6-HOEt-dG) impede DNA replication. The strong blockage effects of the last three lesions were attributable to the presence of hydrogen-bonding donor(s) located on the alkyl functionality of these lesions. Except for O6-POB-dG, which also induced a low frequency of G → T transversions, all other lesions exclusively stimulated G → A transitions. SOS-induced DNA polymerases played redundant roles in bypassing all the O6-alkyl-dG lesions investigated. DNA polymerase IV (Pol IV) and Pol V, however, were uniquely required for inducing the G → A transition for O6-CM-dG exposure. Together, our study expands our knowledge about the recognition of important NOC-derived O6-alkyl-dG lesions by the E. coli DNA replication machinery.
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Affiliation(s)
- Pengcheng Wang
- From the Department of Chemistry, University of California, Riverside, California 92521-0403 and
- the Institute of Surface Analysis and Chemical Biology, University of Jinan, Jinan, Shandong 250022, China
| | - Jiapeng Leng
- From the Department of Chemistry, University of California, Riverside, California 92521-0403 and
| | - Yinsheng Wang
- From the Department of Chemistry, University of California, Riverside, California 92521-0403 and
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11
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Wang P, Wang Y. Cytotoxic and mutagenic properties of O6-alkyl-2'-deoxyguanosine lesions in Escherichia coli cells. J Biol Chem 2018; 293:15033-15042. [PMID: 30068548 PMCID: PMC6166734 DOI: 10.1074/jbc.ra118.004676] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 07/19/2018] [Indexed: 11/06/2022] Open
Abstract
Environmental exposure and cellular metabolism can give rise to DNA alkylation, which can occur on the nitrogen and oxygen atoms of nucleobases, as well as on the phosphate backbone. Although O6-alkyl-2'-deoxyguanosine (O6-alkyl-dG) lesions are known to be associated with cancer, not much is known about how the alkyl group structures in these lesions affect their repair and replicative bypass in vivo or how translesion synthesis DNA polymerases influence the latter process. To answer these questions, here we synthesized oligodeoxyribonucleotides harboring seven O6-alkyl-dG lesions, with the alkyl group being Me, Et, nPr, iPr, nBu, iBu, or sBu, and examined the impact of these lesions on DNA replication in Escherichia coli cells. We found that replication past all the O6-alkyl-dG lesions was highly efficient and that SOS-induced DNA polymerases play redundant roles in bypassing these lesions. Moreover, these lesions directed exclusively the G → A mutation, the frequency of which increased with the size of the alkyl group on the DNA. This could be attributed to the varied repair efficiencies of these lesions by O6-alkylguanine DNA alkyltransferase (MGMT) in cells, which involve the MGMT Ogt and, to a lesser extent, Ada. In conclusion, our study provides important new knowledge about the repair of the O6-alkyl-dG lesions and their recognition by the E. coli DNA replication machinery. Our results suggest that the lesions' carcinogenic potentials may be attributed, at least in part, to their strong mutagenic potential and their efficient bypass by the DNA replication machinery.
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Affiliation(s)
- Pengcheng Wang
- From the Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Yinsheng Wang
- From the Department of Chemistry, University of California, Riverside, California 92521-0403
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12
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Wu J, Wang P, Li L, You C, Wang Y. Cytotoxic and mutagenic properties of minor-groove O2-alkylthymidine lesions in human cells. J Biol Chem 2018; 293:8638-8644. [PMID: 29685891 DOI: 10.1074/jbc.ra118.003133] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 04/11/2018] [Indexed: 12/17/2022] Open
Abstract
Endogenous metabolism, environmental exposure, and cancer chemotherapy can lead to alkylation of DNA. It has been well documented that, among the different DNA alkylation products, minor-groove O2-alkylthymidine (O2-alkyldT) lesions are inefficiently repaired. In the present study, we examined how seven O2-alkyldT lesions, with the alkyl group being a Me, Et, nPr, iPr, nBu, iBu, or sBu, are recognized by the DNA replication machinery in human cells. We found that the replication bypass efficiencies of these lesions decrease with increasing length of the alkyl chain, and that these lesions induce substantial frequencies of T→A and T→G mutations. Replication experiments using isogenic cells deficient in specific translesion synthesis (TLS) DNA polymerases revealed that the absence of polymerase η or polymerase ζ, but not polymerase κ or polymerase ι, significantly decreased both the bypass efficiencies and the mutation frequencies for those O2-alkyldT lesions carrying a straight-chain alkyl group. Moreover, the mutagenic properties of the O2-alkyldT lesions were influenced by the length and topology of the alkyl chain and by TLS polymerases. Together, our results provide important new knowledge about the cytotoxic and mutagenic properties of O2-alkyldT lesions, and illustrate the roles of TLS polymerases in replicative bypass of these lesions in human cells.
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Affiliation(s)
- Jun Wu
- From the Department of Chemistry and
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403
| | - Lin Li
- From the Department of Chemistry and
| | | | - Yinsheng Wang
- From the Department of Chemistry and .,Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403
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13
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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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14
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Price NE, Li L, Gates KS, Wang Y. Replication and repair of a reduced 2΄-deoxyguanosine-abasic site interstrand cross-link in human cells. Nucleic Acids Res 2017; 45:6486-6493. [PMID: 28431012 PMCID: PMC5499640 DOI: 10.1093/nar/gkx266] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 04/13/2017] [Indexed: 02/02/2023] Open
Abstract
Apurinic/apyrimidinic (AP) sites, or abasic sites, which are a common type of endogenous DNA damage, can forge interstrand DNA–DNA cross-links via reaction with the exocyclic amino group on a nearby 2΄-deoxyguanosine or 2΄-deoxyadenosine in the opposite strand. Here, we utilized a shuttle vector method to examine the efficiency and fidelity with which a reduced dG–AP cross-link-containing plasmid was replicated in cultured human cells. Our results showed that the cross-link constituted strong impediments to DNA replication in HEK293T cells, with the bypass efficiencies for the dG- and AP-containing strands being 40% and 20%, respectively. While depletion of polymerase (Pol) η did not perturb the bypass efficiency of the lesion, the bypass efficiency was markedly reduced (to 1–10%) in the isogenic cells deficient in Pol κ, Pol ι or Pol ζ, suggesting the mutual involvement of multiple translesion synthesis polymerases in bypassing the lesion. Additionally, replication of the cross-linked AP residue in HEK293T cells was moderately error-prone, inducing a total of ∼26% single-nucleobase substitutions at the lesion site, whereas replication past the cross-linked dG component occurred at a mutation frequency of ∼8%. Together, our results provided important insights into the effects of an AP-derived interstrand cross-link on the efficiency and accuracy of DNA replication in human cells.
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Affiliation(s)
- Nathan E Price
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Lin Li
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Kent S Gates
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
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15
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Wang P, Amato NJ, Wang Y. Cytotoxic and Mutagenic Properties of C3'-Epimeric Lesions of 2'-Deoxyribonucleosides in Escherichia coli Cells. Biochemistry 2017. [PMID: 28650656 DOI: 10.1021/acs.biochem.7b00146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reactive oxygen species (ROS), resulting from endogenous metabolism and/or environmental exposure, can induce damage to the 2-deoxyribose moiety in DNA. Specifically, a hydrogen atom from each of the five carbon atoms in 2-deoxyribose can be abstracted by hydroxyl radical, and improper chemical repair of the ensuing radicals formed at the C1', C3', and C4' positions can lead to the stereochemical inversion at these sites to yield epimeric 2-deoxyribose lesions. Although ROS-induced single-nucleobase lesions have been well studied, the biological consequences of the C3'-epimeric lesions of 2'-deoxynucleosides, i.e., 2'-deoxyxylonucleosides (dxN), have not been comprehensively investigated. Herein, we assessed the impact of dxN lesions on the efficiency and fidelity of DNA replication in Escherichia coli cells by conducting a competitive replication and adduct bypass assay with single-stranded M13 phage containing a site-specifically incorporated dxN. Our results revealed that, of the four dxN lesions, only dxG constituted a strong impediment to DNA replication, and intriguingly, dxT and dxC conferred replication bypass efficiencies higher than those of the unmodified counterparts. In addition, the three SOS-induced DNA polymerases (Pol II, Pol IV, and Pol V) did not play any appreciable role in bypassing these lesions. Among the four dxNs, only dxA directed a moderate frequency of dCMP misincorporation. These results provided important insights into the impact of the C3'-epimeric lesions on DNA replication in E. coli cells.
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Affiliation(s)
- Pengcheng Wang
- Environmental Toxicology Graduate Program and ‡Department of Chemistry, University of California , Riverside, California 92521-0403, United States
| | - Nicholas J Amato
- Environmental Toxicology Graduate Program and ‡Department of Chemistry, University of California , Riverside, California 92521-0403, United States
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program and ‡Department of Chemistry, University of California , Riverside, California 92521-0403, United States
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16
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Chang SC, Seneviratne UI, Wu J, Tretyakova N, Essigmann JM. 1,3-Butadiene-Induced Adenine DNA Adducts Are Genotoxic but Only Weakly Mutagenic When Replicated in Escherichia coli of Various Repair and Replication Backgrounds. Chem Res Toxicol 2017; 30:1230-1239. [PMID: 28394575 PMCID: PMC5512570 DOI: 10.1021/acs.chemrestox.7b00064] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The adverse effects of the human carcinogen 1,3-butadiene (BD) are believed to be mediated by its DNA-reactive metabolites such as 3,4-epoxybut-1-ene (EB) and 1,2,3,4-diepoxybutane (DEB). The specific DNA adducts responsible for toxic and mutagenic effects of BD, however, have yet to be identified. Recent in vitro polymerase bypass studies of BD-induced adenine (BD-dA) adducts show that DEB-induced N6,N6-DHB-dA (DHB = 2,3-dihydroxybutan-1,4-diyl) and 1,N6-γ-HMHP-dA (HMHP = 2-hydroxy-3-hydroxymethylpropan-1,3-diyl) adducts block replicative DNA polymerases but are bypassed by human polymerases η and κ, leading to point mutations and deletions. In contrast, EB-induced N6-HB-dA (HB = 2-hydroxy-3-buten-1-yl) does not block DNA synthesis and is nonmutagenic. In the present study, we employed a newly established in vivo lesion-induced mutagenesis/genotoxicity assay via next-generation sequencing to evaluate the in vivo biological consequences of S-N6-HB-dA, R,R-N6,N6-DHB-dA, S,S-N6,N6-DHB-dA, and R,S-1,N6-γ-HMHP-dA. In addition, the effects of AlkB-mediated direct reversal repair, MutM and MutY catalyzed base excision repair, and DinB translesion synthesis on the BD-dA adducts in bacterial cells were investigated. BD-dA adducts showed the expected inhibition of DNA replication in vivo but were not substantively mutagenic in any of the genetic environments investigated. This result is in contrast with previous in vitro observations and opens the possibility that E. coli repair and bypass systems other than the ones studied here are able to minimize the mutagenic properties of BD-dA adducts.
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Affiliation(s)
- Shiou-chi Chang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Uthpala I. Seneviratne
- Department of Medicinal Chemistry, and the Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| | - Jie Wu
- BioMicro Center, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Natalia Tretyakova
- Department of Medicinal Chemistry, and the Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455
| | - John M. Essigmann
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
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17
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Lee DF, Lu J, Chang S, Loparo JJ, Xie XS. Mapping DNA polymerase errors by single-molecule sequencing. Nucleic Acids Res 2016; 44:e118. [PMID: 27185891 PMCID: PMC5291262 DOI: 10.1093/nar/gkw436] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/07/2016] [Indexed: 01/24/2023] Open
Abstract
Genomic integrity is compromised by DNA polymerase replication errors, which occur in a sequence-dependent manner across the genome. Accurate and complete quantification of a DNA polymerase's error spectrum is challenging because errors are rare and difficult to detect. We report a high-throughput sequencing assay to map in vitro DNA replication errors at the single-molecule level. Unlike previous methods, our assay is able to rapidly detect a large number of polymerase errors at base resolution over any template substrate without quantification bias. To overcome the high error rate of high-throughput sequencing, our assay uses a barcoding strategy in which each replication product is tagged with a unique nucleotide sequence before amplification. This allows multiple sequencing reads of the same product to be compared so that sequencing errors can be found and removed. We demonstrate the ability of our assay to characterize the average error rate, error hotspots and lesion bypass fidelity of several DNA polymerases.
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Affiliation(s)
- David F Lee
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Jenny Lu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Seungwoo Chang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Xiaoliang S Xie
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
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18
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Wang P, Amato NJ, Zhai Q, Wang Y. Cytotoxic and mutagenic properties of O4-alkylthymidine lesions in Escherichia coli cells. Nucleic Acids Res 2015; 43:10795-803. [PMID: 26400162 PMCID: PMC4678858 DOI: 10.1093/nar/gkv941] [Citation(s) in RCA: 25] [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: 06/27/2015] [Accepted: 09/08/2015] [Indexed: 11/18/2022] Open
Abstract
Due to the abundant presence of alkylating agents in living cells and the environment, DNA alkylation is generally unavoidable. Among the alkylated DNA lesions, O4-alkylthymidine (O4-alkyldT) are known to be highly mutagenic and persistent in mammalian tissues. Not much is known about how the structures of the alkyl group affect the repair and replicative bypass of the O4-alkyldT lesions, or how the latter process is modulated by translesion synthesis polymerases. Herein, we synthesized oligodeoxyribonucleotides harboring eight site-specifically inserted O4-alkyldT lesions and examined their impact on DNA replication in Escherichia coli cells. We showed that the replication past all the O4-alkyldT lesions except (S)- and (R)-sBudT was highly efficient, and these lesions directed very high frequencies of dGMP misincorporation in E. coli cells. While SOS-induced DNA polymerases play redundant roles in bypassing most of the O4-alkyldT lesions, the bypass of (S)- and (R)-sBudT necessitated Pol V. Moreover, Ada was not involved in the repair of any O4-alkyldT lesions, Ogt was able to repair O4-MedT and, to a lesser extent, O4-EtdT and O4-nPrdT, but not other O4-alkyldT lesions. Together, our study provided important new knowledge about the repair of the O4-alkyldT lesions and their recognition by the E. coli replication machinery.
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Affiliation(s)
- Pengcheng Wang
- Environmental Toxicology Graduate Program,University of California, Riverside, CA 92521-0403, USA
| | - Nicholas J Amato
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Qianqian Zhai
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program,University of California, Riverside, CA 92521-0403, USA Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
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19
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Quantitative measurement of transcriptional inhibition and mutagenesis induced by site-specifically incorporated DNA lesions in vitro and in vivo. Nat Protoc 2015; 10:1389-406. [PMID: 26292071 DOI: 10.1038/nprot.2015.094] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aberrant transcription induced by DNA damage may confer risk for the development of cancer and other human diseases. Traditional methods for measuring lesion-induced transcriptional alterations often involve extensive colony screening and DNA sequencing procedures. Here we describe a protocol for the quantitative assessment of the effects of DNA lesions on the efficiency and fidelity of transcription in vitro and in mammalian cells. The method is also amenable to investigating the influence of specific DNA repair proteins on the biological response toward DNA damage during transcription by manipulating their gene expression. Specifically, we present detailed, step-by-step procedures, including DNA template preparation, in vitro and in vivo transcription, RNA purification, reverse-transcription PCR (RT-PCR) and restriction digestion of RT-PCR products. Analyses of restriction fragments of interest are performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and polyacrylamide gel electrophoresis (PAGE). The entire procedure described in this protocol can be completed in 15-20 d.
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20
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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: 54] [Impact Index Per Article: 6.0] [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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21
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Amato NJ, Zhai Q, Navarro DC, Niedernhofer LJ, Wang Y. In vivo detection and replication studies of α-anomeric lesions of 2'-deoxyribonucleosides. Nucleic Acids Res 2015. [PMID: 26202973 PMCID: PMC4787794 DOI: 10.1093/nar/gkv725] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
DNA damage, arising from endogenous metabolism or exposure to environmental agents, may perturb the transmission of genetic information by blocking DNA replication and/or inducing mutations, which contribute to the development of cancer and likely other human diseases. Hydroxyl radical attack on the C1′, C3′ and C4′ of 2-deoxyribose can give rise to epimeric 2-deoxyribose lesions, for which the in vivo occurrence and biological consequences remain largely unexplored. Through independent chemical syntheses of all three epimeric lesions of 2′-deoxyguanosine (dG) and liquid chromatography-tandem mass spectrometry analysis, we demonstrated unambiguously the presence of substantial levels of the α-anomer of dG (α-dG) in calf thymus DNA and in DNA isolated from mouse pancreatic tissues. We further assessed quantitatively the impact of all four α-dN lesions on DNA replication in Escherichia coli by employing a shuttle-vector method. We found that, without SOS induction, all α-dN lesions except α-dA strongly blocked DNA replication and, while replication across α-dA was error-free, replicative bypass of α-dC and α-dG yielded mainly C→A and G→A mutations. In addition, SOS induction could lead to markedly elevated bypass efficiencies for the four α-dN lesions, abolished the G→A mutation for α-dG, pronouncedly reduced the C→A mutation for α-dC and triggered T→A mutation for α-dT. The preferential misincorporation of dTMP opposite the α-dNs could be attributed to the unique base-pairing properties of the nucleobases elicited by the inversion of the configuration of the N-glycosidic linkage. Our results also revealed that Pol V played a major role in bypassing α-dC, α-dG and α-dT in vivo. The abundance of α-dG in mammalian tissue and the impact of the α-dNs on DNA replication demonstrate for the first time the biological significance of this family of DNA lesions.
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Affiliation(s)
- Nicholas J Amato
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Qianqian Zhai
- Department of Chemistry, University of California, Riverside, CA 92521, USA Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Diana C Navarro
- Department of Metabolism and Aging, The Scripps Research Institute Florida, FL 33458, USA
| | - Laura J Niedernhofer
- Department of Metabolism and Aging, The Scripps Research Institute Florida, FL 33458, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, CA 92521, USA
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22
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Fedeles BI, Singh V, Delaney JC, Li D, Essigmann JM. The AlkB Family of Fe(II)/α-Ketoglutarate-dependent Dioxygenases: Repairing Nucleic Acid Alkylation Damage and Beyond. J Biol Chem 2015; 290:20734-20742. [PMID: 26152727 DOI: 10.1074/jbc.r115.656462] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The AlkB family of Fe(II)- and α-ketoglutarate-dependent dioxygenases is a class of ubiquitous direct reversal DNA repair enzymes that remove alkyl adducts from nucleobases by oxidative dealkylation. The prototypical and homonymous family member is an Escherichia coli "adaptive response" protein that protects the bacterial genome against alkylation damage. AlkB has a wide variety of substrates, including monoalkyl and exocyclic bridged adducts. Nine mammalian AlkB homologs exist (ALKBH1-8, FTO), but only a subset functions as DNA/RNA repair enzymes. This minireview presents an overview of the AlkB proteins including recent data on homologs, structural features, substrate specificities, and experimental strategies for studying DNA repair by AlkB family proteins.
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Affiliation(s)
- Bogdan I Fedeles
- Departments of Chemistry and Biological Engineering and the Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Vipender Singh
- Departments of Chemistry and Biological Engineering and the Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - James C Delaney
- Departments of Chemistry and Biological Engineering and the Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Deyu Li
- Departments of Chemistry and Biological Engineering and the Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.
| | - John M Essigmann
- Departments of Chemistry and Biological Engineering and the Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.
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23
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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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24
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Two-dimensional IR spectroscopy of the anti-HIV agent KP1212 reveals protonated and neutral tautomers that influence pH-dependent mutagenicity. Proc Natl Acad Sci U S A 2015; 112:3229-34. [PMID: 25733867 DOI: 10.1073/pnas.1415974112] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Antiviral drugs designed to accelerate viral mutation rates can drive a viral population to extinction in a process called lethal mutagenesis. One such molecule is 5,6-dihydro-5-aza-2'-deoxycytidine (KP1212), a selective mutagen that induces A-to-G and G-to-A mutations in the genome of replicating HIV. The mutagenic property of KP1212 was hypothesized to originate from its amino-imino tautomerism, which would explain its ability to base pair with either G or A. To test the multiple tautomer hypothesis, we used 2D IR spectroscopy, which offers subpicosecond time resolution and structural sensitivity to distinguish among rapidly interconverting tautomers. We identified several KP1212 tautomers and found that >60% of neutral KP1212 is present in the enol-imino form. The abundant proportion of this traditionally rare tautomer offers a compelling structure-based mechanism for pairing with adenine. Additionally, the pKa of KP1212 was measured to be 7.0, meaning a substantial population of KP1212 is protonated at physiological pH. Furthermore, the mutagenicity of KP1212 was found to increase dramatically at pH <7, suggesting a significant biological role for the protonated KP1212 molecules. Overall, our data reveal that the bimodal mutagenic properties of KP1212 result from its unique shape shifting ability that utilizes both tautomerization and protonation.
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25
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You C, Wang J, Dai X, Wang Y. Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA. Nucleic Acids Res 2015; 43:1012-8. [PMID: 25572317 PMCID: PMC4333421 DOI: 10.1093/nar/gku1391] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
N-nitroso compounds represent a common type of environmental and endogenous DNA-damaging agents. After metabolic activation, many N-nitroso compounds are converted into a diazoacetate intermediate that can react with nucleobases to give carboxymethylated DNA adducts such as N3-carboxymethylthymidine (N3-CMdT) and O4-carboxymethylthymidine (O4-CMdT). In this study, we constructed non-replicative plasmids carrying a single N3-CMdT or O4-CMdT, site-specifically positioned in the transcribed strand, to investigate how these lesions compromise the flow of genetic information during transcription. Our results revealed that both N3-CMdT and O4-CMdT substantially inhibited DNA transcription mediated by T7 RNA polymerase or human RNA polymerase II in vitro and in human cells. In addition, we found that N3-CMdT and O4-CMdT were miscoding lesions and predominantly directed the misinsertion of uridine and guanosine, respectively. Our results also suggested that these carboxymethylated thymidine lesions may constitute efficient substrates for transcription-coupled nucleotide excision repair in human cells. These findings provided important new insights into the biological consequences of the carboxymethylated DNA lesions in living cells.
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Affiliation(s)
- Changjun You
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Jianshuang Wang
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Xiaoxia Dai
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
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26
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You C, Wang P, Dai X, Wang Y. Transcriptional bypass of regioisomeric ethylated thymidine lesions by T7 RNA polymerase and human RNA polymerase II. Nucleic Acids Res 2014; 42:13706-13. [PMID: 25404131 PMCID: PMC4267633 DOI: 10.1093/nar/gku1183] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Alkylative damage to DNA can be induced by environmental chemicals, endogenous metabolites and some commonly prescribed chemotherapeutic agents. The regioisomeric N3-, O(2)- and O(4)-ethylthymidine (N3-, O(2)- and O(4)-EtdT, respectively) represent an important class of ethylated DNA lesions. Using nonreplicative double-stranded vectors containing an N3-EtdT, O(2)-EtdT or O(4)-EtdT at a defined site in the template strand, herein we examined the effects of these lesions on DNA transcription mediated by single-subunit T7 RNA polymerase or multisubunit human RNA polymerase II in vitro and in human cells. We found that O(4)-EtdT is highly mutagenic and exclusively induces the misincorporation of guanine opposite the lesion, whereas N3-EtdT and O(2)-EtdT display promiscuous miscoding properties during transcription. In addition, N3-EtdT and O(2)-EtdT were found to inhibit strongly DNA transcription in vitro and in certain human cells. Moreover, N3-EtdT, but not O(2)-EtdT or O(4)-EtdT, is an efficient substrate for transcription-coupled nucleotide excision repair. These findings provide new important insights into how these alkylated DNA lesions compromise the flow of genetic information, which may help to understand the risk of these lesions in living cells.
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Affiliation(s)
- Changjun You
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521-0403, USA
| | - Xiaoxia Dai
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521-0403, USA
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27
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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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28
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Zhai Q, Wang P, Cai Q, Wang Y. Syntheses and characterizations of the in vivo replicative bypass and mutagenic properties of the minor-groove O2-alkylthymidine lesions. Nucleic Acids Res 2014; 42:10529-37. [PMID: 25120272 PMCID: PMC4176383 DOI: 10.1093/nar/gku748] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Endogenous metabolism, environmental exposure, and treatment with some chemotherapeutic agents can all give rise to DNA alkylation, which can occur on the phosphate backbone as well as the ring nitrogen or exocyclic nitrogen and oxygen atoms of nucleobases. Previous studies showed that the minor-groove O2-alkylated thymidine (O2-alkyldT) lesions are poorly repaired and persist in mammalian tissues. In the present study, we synthesized oligodeoxyribonucleotides harboring seven O2-alkyldT lesions, with the alkyl group being a Me, Et, nPr, iPr, nBu, iBu or sBu, at a defined site and examined the impact of these lesions on DNA replication in Escherichia coli cells. Our results demonstrated that the replication bypass efficiencies of the O2-alkyldT lesions decreased with the chain length of the alkyl group, and these lesions directed promiscuous nucleotide misincorporation in E. coli cells. We also found that deficiency in Pol V, but not Pol II or Pol IV, led to a marked drop in bypass efficiencies for most O2-alkyldT lesions. We further showed that both Pol IV and Pol V were essential for the misincorporation of dCMP opposite these minor-groove DNA lesions, whereas only Pol V was indispensable for the T→A transversion introduced by these lesions. Depletion of Pol II, however, did not lead to any detectable alterations in mutation frequencies for any of the O2-alkyldT lesions. Thus, our study provided important new knowledge about the cytotoxic and mutagenic properties of the O2-alkyldT lesions and revealed the roles of the SOS-induced DNA polymerases in bypassing these lesions in E. coli cells.
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Affiliation(s)
- Qianqian Zhai
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA
| | - Qian Cai
- Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, CA 92521, USA Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA
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29
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Tautomerism provides a molecular explanation for the mutagenic properties of the anti-HIV nucleoside 5-aza-5,6-dihydro-2'-deoxycytidine. Proc Natl Acad Sci U S A 2014; 111:E3252-9. [PMID: 25071207 DOI: 10.1073/pnas.1405635111] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Viral lethal mutagenesis is a strategy whereby the innate immune system or mutagenic pool nucleotides increase the error rate of viral replication above the error catastrophe limit. Lethal mutagenesis has been proposed as a mechanism for several antiviral compounds, including the drug candidate 5-aza-5,6-dihydro-2'-deoxycytidine (KP1212), which causes A-to-G and G-to-A mutations in the HIV genome, both in tissue culture and in HIV positive patients undergoing KP1212 monotherapy. This work explored the molecular mechanism(s) underlying the mutagenicity of KP1212, and specifically whether tautomerism, a previously proposed hypothesis, could explain the biological consequences of this nucleoside analog. Establishing tautomerism of nucleic acid bases under physiological conditions has been challenging because of the lack of sensitive methods. This study investigated tautomerism using an array of spectroscopic, theoretical, and chemical biology approaches. Variable temperature NMR and 2D infrared spectroscopic methods demonstrated that KP1212 existed as a broad ensemble of interconverting tautomers, among which enolic forms dominated. The mutagenic properties of KP1212 were determined empirically by in vitro and in vivo replication of a single-stranded vector containing a single KP1212. It was found that KP1212 paired with both A (10%) and G (90%), which is in accord with clinical observations. Moreover, this mutation frequency is sufficient for pushing a viral population over its error catastrophe limit, as observed before in cell culture studies. Finally, a model is proposed that correlates the mutagenicity of KP1212 with its tautomeric distribution in solution.
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30
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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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31
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Polymerase exchange on single DNA molecules reveals processivity clamp control of translesion synthesis. Proc Natl Acad Sci U S A 2014; 111:7647-52. [PMID: 24825884 DOI: 10.1073/pnas.1321076111] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Translesion synthesis (TLS) by Y-family DNA polymerases alleviates replication stalling at DNA damage. Ring-shaped processivity clamps play a critical but ill-defined role in mediating exchange between Y-family and replicative polymerases during TLS. By reconstituting TLS at the single-molecule level, we show that the Escherichia coli β clamp can simultaneously bind the replicative polymerase (Pol) III and the conserved Y-family Pol IV, enabling exchange of the two polymerases and rapid bypass of a Pol IV cognate lesion. Furthermore, we find that a secondary contact between Pol IV and β limits Pol IV synthesis under normal conditions but facilitates Pol III displacement from the primer terminus following Pol IV induction during the SOS DNA damage response. These results support a role for secondary polymerase clamp interactions in regulating exchange and establishing a polymerase hierarchy.
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32
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Greenberg MM. Looking beneath the surface to determine what makes DNA damage deleterious. Curr Opin Chem Biol 2014; 21:48-55. [PMID: 24762292 DOI: 10.1016/j.cbpa.2014.03.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 03/21/2014] [Accepted: 03/25/2014] [Indexed: 02/07/2023]
Abstract
Apurinic/apyrimidinic and oxidized abasic sites are chemically reactive DNA lesions that are produced by a variety of damaging agents. The effects of these molecules that lack a Watson-Crick base on polymerase enzymes are well documented. More recently, multiple consequences of the electrophilic nature of abasic lesions have been revealed. Members of this family of DNA lesions have been shown to inactivate repair enzymes and undergo spontaneous transformation into more deleterious forms of damage. Abasic site reactivity provides insight into the chemical basis for the cytotoxicity of DNA damaging agents that produce them and are valuable examples of how looking beneath the surface of seemingly simple molecules can reveal biologically relevant chemical complexity.
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Affiliation(s)
- Marc M Greenberg
- Department of Chemistry, Johns Hopkins University, 3400N, Charles Street, Baltimore, MD 21218, United States.
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33
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Shrivastav N, Fedeles BI, Li D, Delaney JC, Frick LE, Foti JJ, Walker GC, Essigmann JM. A chemical genetics analysis of the roles of bypass polymerase DinB and DNA repair protein AlkB in processing N2-alkylguanine lesions in vivo. PLoS One 2014; 9:e94716. [PMID: 24733044 PMCID: PMC3986394 DOI: 10.1371/journal.pone.0094716] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 03/18/2014] [Indexed: 01/06/2023] Open
Abstract
DinB, the E. coli translesion synthesis polymerase, has been shown to bypass several N2-alkylguanine adducts in vitro, including N2-furfurylguanine, the structural analog of the DNA adduct formed by the antibacterial agent nitrofurazone. Recently, it was demonstrated that the Fe(II)- and α-ketoglutarate-dependent dioxygenase AlkB, a DNA repair enzyme, can dealkylate in vitro a series of N2-alkyguanines, including N2-furfurylguanine. The present study explored, head to head, the in vivo relative contributions of these two DNA maintenance pathways (replicative bypass vs. repair) as they processed a series of structurally varied, biologically relevant N2-alkylguanine lesions: N2-furfurylguanine (FF), 2-tetrahydrofuran-2-yl-methylguanine (HF), 2-methylguanine, and 2-ethylguanine. Each lesion was chemically synthesized and incorporated site-specifically into an M13 bacteriophage genome, which was then replicated in E. coli cells deficient or proficient for DinB and AlkB (4 strains in total). Biochemical tools were employed to analyze the relative replication efficiencies of the phage (a measure of the bypass efficiency of each lesion) and the base composition at the lesion site after replication (a measure of the mutagenesis profile of each lesion). The main findings were: 1) Among the lesions studied, the bulky FF and HF lesions proved to be strong replication blocks when introduced site-specifically on a single-stranded vector in DinB deficient cells. This toxic effect disappeared in the strains expressing physiological levels of DinB. 2) AlkB is known to repair N2-alkylguanine lesions in vitro; however, the presence of AlkB showed no relief from the replication blocks induced by FF and HF in vivo. 3) The mutagenic properties of the entire series of N2-alkyguanines adducts were investigated in vivo for the first time. None of the adducts were mutagenic under the conditions evaluated, regardless of the DinB or AlkB cellular status. Taken together, the data indicated that the cellular pathway to combat bulky N2-alkylguanine DNA adducts was DinB-dependent lesion bypass.
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Affiliation(s)
- Nidhi Shrivastav
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Bogdan I. Fedeles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Deyu Li
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - James C. Delaney
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Lauren E. Frick
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - James J. Foti
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Graham C. Walker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - John M. Essigmann
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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34
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Zhai Q, Wang P, Wang Y. Cytotoxic and mutagenic properties of regioisomeric O²-, N3- and O⁴-ethylthymidines in bacterial cells. Carcinogenesis 2014; 35:2002-6. [PMID: 24710626 DOI: 10.1093/carcin/bgu085] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Exposure to environmental agents and endogenous metabolism can both give rise to DNA alkylation. Thymine is known to be alkylated at O(2), N3 and O(4) positions; however, it remains poorly explored how the regioisomeric alkylated thymidine lesions compromise the flow of genetic information by perturbing DNA replication in cells. Herein, we assessed the differential recognition of the regioisomeric O(2)-, N3- and O(4)-ethylthymidine (O(2)-, N3- and O(4)-EtdT) by the DNA replication machinery of Escherichia coli cells. We found that O(4)-EtdT did not inhibit appreciably DNA replication, whereas O(2)- and N3-EtdT were strongly blocking to DNA replication. In addition, O(4)-EtdT induced a very high frequency of T→C mutation, whereas nucleotide incorporation opposite O(2)- and N3-EtdT was promiscuous. Replication experiments with the use of polymerase-deficient cells revealed that Pol V constituted the major polymerase for the mutagenic bypass of all three EtdT lesions, though Pol IV also contributed to the T→G mutation induced by O(2)- and N3-EtdT. The distinct cytotoxic and mutagenic properties of the three regioisomeric lesions could be attributed to their unique chemical properties.
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Affiliation(s)
| | - Pengcheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA
| | - Yinsheng Wang
- Department of Chemistry and Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA
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35
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Liang Q, Dexheimer TS, Zhang P, Rosenthal AS, Villamil MA, You C, Zhang Q, Chen J, Ott CA, Sun H, Luci DK, Yuan B, Simeonov A, Jadhav A, Xiao H, Wang Y, Maloney DJ, Zhuang Z. A selective USP1-UAF1 inhibitor links deubiquitination to DNA damage responses. Nat Chem Biol 2014; 10:298-304. [PMID: 24531842 DOI: 10.1038/nchembio.1455] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 12/11/2013] [Indexed: 12/31/2022]
Abstract
Protein ubiquitination and deubiquitination are central to the control of a large number of cellular pathways and signaling networks in eukaryotes. Although the essential roles of ubiquitination have been established in the eukaryotic DNA damage response, the deubiquitination process remains poorly defined. Chemical probes that perturb the activity of deubiquitinases (DUBs) are needed to characterize the cellular function of deubiquitination. Here we report ML323 (2), a highly potent inhibitor of the USP1-UAF1 deubiquitinase complex with excellent selectivity against human DUBs, deSUMOylase, deneddylase and unrelated proteases. Using ML323, we interrogated deubiquitination in the cellular response to UV- and cisplatin-induced DNA damage and revealed new insights into the requirement of deubiquitination in the DNA translesion synthesis and Fanconi anemia pathways. Moreover, ML323 potentiates cisplatin cytotoxicity in non-small cell lung cancer and osteosarcoma cells. Our findings point to USP1-UAF1 as a key regulator of the DNA damage response and a target for overcoming resistance to the platinum-based anticancer drugs.
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Affiliation(s)
- Qin Liang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Thomas S Dexheimer
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Ping Zhang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Andrew S Rosenthal
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Mark A Villamil
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Changjun You
- Department of Chemistry, University of California-Riverside, Riverside, California, USA
| | - Qiuting Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi, China
| | - Junjun Chen
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Christine A Ott
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
| | - Hongmao Sun
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Diane K Luci
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Bifeng Yuan
- Department of Chemistry, University of California-Riverside, Riverside, California, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Ajit Jadhav
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Hui Xiao
- Laboratory of Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California-Riverside, Riverside, California, USA
| | - David J Maloney
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Zhihao Zhuang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, USA
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36
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Xing XW, Liu YL, Vargas M, Wang Y, Feng YQ, Zhou X, Yuan BF. Mutagenic and cytotoxic properties of oxidation products of 5-methylcytosine revealed by next-generation sequencing. PLoS One 2013; 8:e72993. [PMID: 24066027 PMCID: PMC3774748 DOI: 10.1371/journal.pone.0072993] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 07/23/2013] [Indexed: 11/19/2022] Open
Abstract
5-methylcytosine (5-mC) can be sequentially oxidized to 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and finally to 5-carboxylcytosine (5-caC), which is thought to function in active DNA cytosine demethylation in mammals. Although the roles of 5-mC in epigenetic regulation of gene expression are well established, the effects of 5-hmC, 5-foC and 5-caC on DNA replication remain unclear. Here we report a systematic study on how these cytosine derivatives (5-hmC, 5-foC and 5-caC) perturb the efficiency and accuracy of DNA replication using shuttle vector technology in conjugation with next-g
sequencing. Our results demonstrated that, in Escherichia coli cells, all the cytosine derivatives could induce CT transition mutation at frequencies of 0.17%–1.12%, though no effect on replication efficiency was observed. These findings provide an important new insight on the potential mutagenic properties of cytosine derivatives occurring as the intermediates of DNA demethylation.
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Affiliation(s)
- Xi-Wen Xing
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, P.R. China
| | - Yu-Li Liu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, P.R. China
| | - Mario Vargas
- Department of Chemistry, University of California Riverside, Riverside, California, United States of America
| | - Yinsheng Wang
- Department of Chemistry, University of California Riverside, Riverside, California, United States of America
| | - Yu-Qi Feng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, P.R. China
| | - Xiang Zhou
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, P.R. China
- * E-mail: (BFY); (XZ)
| | - Bi-Feng Yuan
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, P.R. China
- * E-mail: (BFY); (XZ)
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37
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You C, Swanson AL, Dai X, Yuan B, Wang J, Wang Y. Translesion synthesis of 8,5'-cyclopurine-2'-deoxynucleosides by DNA polymerases η, ι, and ζ. J Biol Chem 2013; 288:28548-56. [PMID: 23965998 DOI: 10.1074/jbc.m113.480459] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Reactive oxygen species can give rise to a battery of DNA damage products including the 8,5'-cyclo-2'-deoxyadenosine (cdA) and 8,5'-cyclo-2'-deoxyguanosine (cdG) tandem lesions. The 8,5'-cyclopurine-2'-deoxynucleosides are quite stable lesions and are valid and reliable markers of oxidative DNA damage. However, it remains unclear how these lesions compromise DNA replication in mammalian cells. Previous in vitro biochemical assays have suggested a role for human polymerase (Pol) η in the insertion step of translesion synthesis (TLS) across the (5'S) diastereomers of cdA and cdG. Using in vitro steady-state kinetic assay, herein we showed that human Pol ι and a two-subunit yeast Pol ζ complex (REV3/REV7) could function efficiently in the insertion and extension steps, respectively, of TLS across S-cdA and S-cdG; human Pol κ and Pol η could also extend past these lesions, albeit much less efficiently. Results from a quantitative TLS assay showed that, in human cells, S-cdA and S-cdG inhibited strongly DNA replication and induced substantial frequencies of mutations at the lesion sites. Additionally, Pol η, Pol ι, and Pol ζ, but not Pol κ, had important roles in promoting replication through S-cdA and S-cdG in human cells. Based on these results, we propose a model for TLS across S-cdA and S-cdG in human cells, where Pol η and/or Pol ι carries out nucleotide insertion opposite the lesion, whereas Pol ζ executes the extension step.
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38
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Li D, Fedeles BI, Shrivastav N, Delaney JC, Yang X, Wong C, Drennan CL, Essigmann JM. Removal of N-alkyl modifications from N(2)-alkylguanine and N(4)-alkylcytosine in DNA by the adaptive response protein AlkB. Chem Res Toxicol 2013; 26:1182-7. [PMID: 23773213 PMCID: PMC3748507 DOI: 10.1021/tx400096m] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
![]()
The
AlkB enzyme is an Fe(II)- and α-ketoglutarate-dependent
dioxygenase that repairs DNA alkyl lesions by a direct reversal of
damage mechanism as part of the adaptive response in E. coli. The reported substrate scope of AlkB includes simple DNA alkyl
adducts, such as 1-methyladenine, 3-methylcytosine, 3-ethylcytosine,
1-methylguanine, 3-methylthymine, and N6-methyladenine, as well as more complex DNA adducts, such as 1,N6-ethenoadenine, 3,N4-ethenocytosine, and 1,N6-ethanoadenine.
Previous studies have revealed, in a piecemeal way, that AlkB has
an impressive repertoire of substrates. The present study makes two
additions to this list, showing that alkyl adducts on the N2 position of guanine and N4 position of cytosine are also substrates for AlkB. Using
high resolution ESI-TOF mass spectrometry, we show that AlkB has the
biochemical capability to repair in vitroN2-methylguanine, N2-ethylguanine, N2-furan-2-yl-methylguanine, N2-tetrahydrofuran-2-yl-methylguanine, and N4-methylcytosine in ssDNA but not in dsDNA.
When viewed together with previous work, the experimental data herein
demonstrate that AlkB is able to repair all simple N-alkyl adducts occurring at the Watson–Crick base
pairing interface of the four DNA bases, confirming AlkB as a versatile
gatekeeper of genomic integrity under alkylation stress.
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Affiliation(s)
- Deyu Li
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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39
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Taggart DJ, Camerlengo TL, Harrison JK, Sherrer SM, Kshetry AK, Taylor JS, Huang K, Suo Z. A high-throughput and quantitative method to assess the mutagenic potential of translesion DNA synthesis. Nucleic Acids Res 2013; 41:e96. [PMID: 23470999 PMCID: PMC3632128 DOI: 10.1093/nar/gkt141] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cellular genomes are constantly damaged by endogenous and exogenous agents that covalently and structurally modify DNA to produce DNA lesions. Although most lesions are mended by various DNA repair pathways in vivo, a significant number of damage sites persist during genomic replication. Our understanding of the mutagenic outcomes derived from these unrepaired DNA lesions has been hindered by the low throughput of existing sequencing methods. Therefore, we have developed a cost-effective high-throughput short oligonucleotide sequencing assay that uses next-generation DNA sequencing technology for the assessment of the mutagenic profiles of translesion DNA synthesis catalyzed by any error-prone DNA polymerase. The vast amount of sequencing data produced were aligned and quantified by using our novel software. As an example, the high-throughput short oligonucleotide sequencing assay was used to analyze the types and frequencies of mutations upstream, downstream and at a site-specifically placed cis-syn thymidine-thymidine dimer generated individually by three lesion-bypass human Y-family DNA polymerases.
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Affiliation(s)
- David J Taggart
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, USA
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40
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A quantitative assay for assessing the effects of DNA lesions on transcription. Nat Chem Biol 2013; 8:817-22. [PMID: 22902614 PMCID: PMC3509257 DOI: 10.1038/nchembio.1046] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 06/22/2012] [Indexed: 12/12/2022]
Abstract
Most mammalian cells in nature are quiescent but actively transcribing mRNA for normal physiological processes; thus, it is important to investigate how endogenous and exogenous DNA damage compromises transcription in cells. Here we describe a new competitive transcription and adduct bypass (CTAB) assay to determine the effects of DNA lesions on the fidelity and efficiency of transcription. Using this strategy, we demonstrate that the oxidatively induced lesions 8,5'-cyclo-2'-deoxyadenosine (cdA) and 8,5'-cyclo-2'-deoxyguanosine (cdG) and the methylglyoxal-induced lesion N(2)-(1-carboxyethyl)-2'-deoxyguanosine (N(2)-CEdG) strongly inhibited transcription in vitro and in mammalian cells. In addition, cdA and cdG, but not N(2)-CEdG, induced transcriptional mutagenesis in vitro and in vivo. Furthermore, when located on the template DNA strand, all examined lesions were primarily repaired by transcription-coupled nucleotide excision repair in mammalian cells. This newly developed CTAB assay should be generally applicable for quantitatively assessing how other DNA lesions affect DNA transcription in vitro and in cells.
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41
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Brabec V, Malina J, Margiotta N, Natile G, Kasparkova J. Thermodynamic and mechanistic insights into translesion DNA synthesis catalyzed by Y-family DNA polymerase across a bulky double-base lesion of an antitumor platinum drug. Chemistry 2012; 18:15439-48. [PMID: 23065963 DOI: 10.1002/chem.201202117] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Indexed: 01/10/2023]
Abstract
To determine how the Y-family translesion DNA polymerase η (Polη) processes lesions remains fundamental to understanding the molecular origins of the mutagenic translesion bypass. We utilized model systems employing a DNA double-base lesion derived from 1,2-GG intrastrand cross-links of a new antitumor Pt(II) complex containing a bulky carrier ligand, namely [PtCl(2)(cis-1,4-dach)] (DACH=diaminocyclohexane). The catalytic efficiency of Polη for the insertion of correct dCTP, with respect to the other incorrect nucleotides, opposite the 1,2-GG cross-link was markedly reduced by the DACH carrier ligand. This reduced efficiency of Polη to incorporate the correct dCTP could be due to a more extensive DNA unstacking and deformation of the minor groove induced in the DNA by the cross-link of bulky [PtCl(2)(cis-1,4-dach)]. The major products of the bypass of this double-base lesion produced by [PtCl(2)(cis-1,4-dach)] by Polη resulted from misincorporation of dATP opposite the platinated G residues. The results of the present work support the thesis that this misincorporation could be due to sterical effects of the bulkier 1,4-DACH ligand hindering the formation of the Polη-DNA-incoming nucleotide complex. Calorimetric analysis suggested that thermodynamic factors may contribute to the forces that governed enhanced incorporation of the incorrect dATP by Polη as well.
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Affiliation(s)
- Viktor Brabec
- Department of Molecular Biophysics and Pharmacology, Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska 135, 61265 Brno, Czech Republic
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42
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Oxidatively generated complex DNA damage: tandem and clustered lesions. Cancer Lett 2012; 327:5-15. [PMID: 22542631 DOI: 10.1016/j.canlet.2012.04.005] [Citation(s) in RCA: 172] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 04/02/2012] [Accepted: 04/15/2012] [Indexed: 11/22/2022]
Abstract
There is an increasing interest for oxidatively generated complex lesions that are potentially more detrimental than single oxidized nucleobases. In this survey, the recently available information on the formation and processing of several classes of complex DNA damage formed upon one radical hit including mostly hydroxyl radical and one-electron oxidants is critically reviewed. The modifications include tandem base lesions, DNA-protein cross-links and intrastrand (purine 5',8-cyclonucleosides, adjacent base cross-links) and interstrand cross-links. Information is also provided on clustered lesions produced essentially by exposure of cells to ionizing radiation and high energetic heavy ions through the involvement of multiple radical events that induce several lesions DNA in a close spatial vicinity. These consist mainly of double strand breaks (DSBs) and non-DSB clustered lesions that are referred as to oxidatively generated clustered DNA lesions (OCDLs).
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43
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Greenberg MM. The formamidopyrimidines: purine lesions formed in competition with 8-oxopurines from oxidative stress. Acc Chem Res 2012; 45:588-97. [PMID: 22077696 DOI: 10.1021/ar2002182] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
DNA is constantly exposed to agents that induce structural damage, from sources both internal and external to an organism. Endogenous species, such as oxidizing chemicals, and exogenous agents, such as ultraviolet rays in sunlight, together produce more than 70 distinct chemical modifications of native nucleotides. Of these, about 15 of the lesions have been detected in cellular DNA. This kind of structural DNA damage can be cytotoxic, carcinogenic, or both and is being linked to an increasingly lengthy list of diseases. The formamidopyrimidine (Fapy) lesions are a family of DNA lesions that result after purines undergo oxidative stress. The Fapy lesions are produced in yields comparable to the 8-oxopurines, which, owing in part to a perception of mutagenicity in some quarters, have been subjected to intense research scrutiny. But despite the comparable abundance of the formamidopyrimidines and the 8-oxopurines, until recently very little was known about the effects of Fapy lesions on biochemical processes involving DNA or on the structure and stability of the genomic material. In this Account, we discuss the detection of Fapy lesions in DNA and the mechanism proposed for their formation. We also describe methods for the chemical synthesis of oligonucleotides containing Fapy·dA or Fapy·dG and the outcomes of chemical and biochemical studies utilizing these compounds. These experiments reveal that the formamidopyrimidines decrease the fidelity of polymerases and are substrates for DNA repair enzymes. The mutation frequency of Fapy·dG in mammals is even greater than that of 8-oxodGuo (8-oxo-7,8-dihydro-2'-deoxyguanosine, one of the 8-oxopurines), suggesting that this lesion could be a useful biomarker and biologically significant. Despite clear similarities, the formamidopyrimidines have lived in the shadow of the corresponding 8-oxopurine lesions. But the recent development of methods for synthesizing oligonucleotides containing Fapy·dA or Fapy·dG has accelerated research on these lesions, revealing that the formamidopyrimidines are repaired as efficiently and, in some cases, more rapidly than the 8-oxopurines. Fapy·dG appears to be a lesion of biochemical consequence, and further study of its mutagenicity, repair, and interactions with DNA structure will better define the cellular details involving this important product of DNA stress.
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Affiliation(s)
- Marc M. Greenberg
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, United States
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44
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Delaney S, Jarem DA, Volle CB, Yennie CJ. Chemical and biological consequences of oxidatively damaged guanine in DNA. Free Radic Res 2012; 46:420-41. [PMID: 22239655 DOI: 10.3109/10715762.2011.653968] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Of the four native nucleosides, 2'-deoxyguanosine (dGuo) is most easily oxidized. Two lesions derived from dGuo are 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (Fapy)∙dGuo. Furthermore, while steady-state levels of 8-oxodGuo can be detected in genomic DNA, it is also known that 8-oxodGuo is more easily oxidized than dGuo. Thus, 8-oxodGuo is susceptible to further oxidation to form several hyperoxidized dGuo products. This review addresses the structural impact, the mutagenic and genotoxic potential, and biological implications of oxidatively damaged DNA, in particular 8-oxodGuo, Fapy∙dGuo, and the hyperoxidized dGuo products.
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Affiliation(s)
- Sarah Delaney
- Department of Chemistry, Brown University, Providence, RI 02912, USA.
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45
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Yuan B, Wang J, Cao H, Sun R, Wang Y. High-throughput analysis of the mutagenic and cytotoxic properties of DNA lesions by next-generation sequencing. Nucleic Acids Res 2011; 39:5945-54. [PMID: 21470959 PMCID: PMC3152323 DOI: 10.1093/nar/gkr159] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Human cells are constantly exposed to environmental and endogenous agents which can induce damage to DNA. Understanding the implications of these DNA modifications in the etiology of human diseases requires the examination about how these DNA lesions block DNA replication and induce mutations in cells. All previously reported shuttle vector-based methods for investigating the cytotoxic and mutagenic properties of DNA lesions in cells have low-throughput, where plasmids containing individual lesions are transfected into cells one lesion at a time and the products from the replication of individual lesions are analyzed separately. The advent of next-generation sequencing (NGS) technology has facilitated investigators to design scientific approaches that were previously not technically feasible or affordable. In this study, we developed a new method employing NGS, together with shuttle vector technology, to have a multiplexed and quantitative assessment of how DNA lesions perturb the efficiency and accuracy of DNA replication in cells. By using this method, we examined the replication of four carboxymethylated DNA lesions and two oxidatively induced bulky DNA lesions including (5′S) diastereomers of 8,5′-cyclo-2′-deoxyguanosine (cyclo-dG) and 8,5′-cyclo-2′-deoxyadenosine (cyclo-dA) in five different strains of Escherichia coli cells. We further validated the results obtained from NGS using previously established methods. Taken together, the newly developed method provided a high-throughput and readily affordable method for assessing quantitatively how DNA lesions compromise the efficiency and fidelity of DNA replication in cells.
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Affiliation(s)
- Bifeng Yuan
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
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46
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Yuan B, You C, Andersen N, Jiang Y, Moriya M, O'Connor TR, Wang Y. The roles of DNA polymerases κ and ι in the error-free bypass of N2-carboxyalkyl-2'-deoxyguanosine lesions in mammalian cells. J Biol Chem 2011; 286:17503-11. [PMID: 21454642 DOI: 10.1074/jbc.m111.232835] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
To counteract the deleterious effects of DNA damage, cells are equipped with specialized polymerases to bypass DNA lesions. Previous biochemical studies revealed that DinB family DNA polymerases, including Escherichia coli DNA polymerase IV and human DNA polymerase κ, efficiently incorporate the correct nucleotide opposite some N(2)-modified 2'-deoxyguanosine derivatives. Herein, we used shuttle vector technology and demonstrated that deficiency in Polk or Poli in mouse embryonic fibroblast (MEF) cells resulted in elevated frequencies of G→T and G→A mutations at N(2)-(1-carboxyethyl)-2'-deoxyguanosine (N(2)-CEdG) and N(2)-carboxymethyl-2'-deoxyguanosine (N(2)-CMdG) sites. Steady-state kinetic measurements revealed that human DNA polymerase ι preferentially inserts the correct nucleotide, dCMP, opposite N(2)-CEdG lesions. In contrast, no mutation was found after the N(2)-CEdG- and N(2)-CMdG-bearing plasmids were replicated in POLH-deficient human cells or Rev3-deficient MEF cells. Together, our results revealed that, in mammalian cells, both polymerases κ and ι are necessary for the error-free bypass of N(2)-CEdG and N(2)-CMdG. However, in the absence of polymerase κ or ι, other translesion synthesis polymerase(s) could incorporate nucleotide(s) opposite these lesions but would do so inaccurately.
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Affiliation(s)
- Bifeng Yuan
- From the Department of Chemistry, University of California, Riverside, California 92521, USA
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47
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Yuan B, O’Connor TR, Wang Y. 6-Thioguanine and S⁶-methylthioguanine are mutagenic in human cells. ACS Chem Biol 2010; 5:1021-7. [PMID: 20806951 DOI: 10.1021/cb100214b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thiopurines are effective immunosuppressants and anticancer agents. However, the long-term use of thiopurines was found to be associated with a significantly increased risk of various types of cancer. To date, the specific mechanism(s) underlying the carcinogenicity associated with thiopurine treatment remain(s) unclear. Herein, we constructed duplex pTGFP-Hha10 shuttle vectors carrying a 6-thioguanine ((S)G) or S⁶-methylthioguanine (S⁶mG) at a unique site and allowed the vectors to propagate in three different human cell lines. Analysis of the replication products revealed that although neither thionucleoside blocked considerably DNA replication in any of the human cell lines, both (S)G and S⁶mG were mutagenic, resulting in G→A mutation at frequencies of ~8% and ~39%, respectively. Consistent with what was found from our previous study in E. coli cells, our data demonstrated that the mutagenic properties of (S)G and S⁶mG provided significant evidence for mutation induction as a potential carcinogenic mechanism associated with chronic thiopurine intervention.
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Affiliation(s)
- Bifeng Yuan
- Department of Chemistry, University of California, Riverside, California 92521
| | - Timothy R. O’Connor
- Biology Division, Beckman Research Institute, City of Hope National Medical Center, Duarte, California 91010
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, California 92521
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48
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Seneviratne U, Antsypovich S, Dorr DQ, Dissanayake T, Kotapati S, Tretyakova N. DNA oligomers containing site-specific and stereospecific exocyclic deoxyadenosine adducts of 1,2,3,4-diepoxybutane: synthesis, characterization, and effects on DNA structure. Chem Res Toxicol 2010; 23:1556-67. [PMID: 20873715 DOI: 10.1021/tx100146v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
1,2,3,4-Diepoxybutane (DEB) is a carcinogenic metabolite of 1,3-butadiene (BD), an important industrial and environmental chemical present in urban air and in cigarette smoke. DEB is considered the ultimate carcinogenic species of BD because of its potent genotoxicity and mutagenicity attributed to its ability to form DNA-DNA cross-links and exocyclic nucleoside adducts. Mutagenesis studies suggest that DEB adducts formed at adenine bases may be critically important, as it induces large numbers of A → T transversions. We have recently identified three types of exocyclic DEB-dA lesions: N⁶,N⁶-(2,3-dihydroxybutan-1,4-diyl)-2'-deoxyadenosine (N⁶,N⁶-DHB-dA), 1,N⁶-(2-hydroxy-3-hydroxymethylpropan-1,3-diyl)-2'-deoxyadenosine (1,N⁶-γ-HMHP-dA), and 1,N⁶-(1-hydroxymethyl-2-hydroxypropan-1,3-diyl)-2'-deoxyadenosine (1,N⁶-α-HMHP-dA) [Seneviratne, U., et al. (2010) Chem. Res. Toxicol. 23, 118-133]. In the work presented here, a postsynthetic methodology for preparing DNA oligomers containing stereospecific and site-specific N⁶,N⁶-DHB-dA and 1,N⁶-γ-HMHP-dA adducts was developed. DNA oligomers containing site-specific 6-chloropurine were coupled with optically pure 1-amino-2-hydroxy-3,4-epoxybutanes to generate oligomers containing N⁶-(2-hydroxy-3,4-epoxybut-1-yl)-2'-deoxyadenosine adducts, followed by their spontaneous cyclization to 1,N⁶-γ-HMHP-dA lesions. N⁶,N⁶-DHB-dA containing strands were prepared analogously by coupling 6-chloropurine containing DNA with (3S,4S)- or (3R,4R)-pyrrolidine-3,4-diols. Oligodeoxynucleotide structures were confirmed by ESI-MS, exonuclease ladder sequencing, and HPLC-MS/MS of enzymatic digests. UV melting and CD spectroscopy studies of DNA duplexes containing N⁶,N⁶-DHB-dA and 1,N⁶-γ-HMHP-dA revealed that both lesions lower the thermodynamic stability of DNA. Interestingly, structurally modified DNA duplexes were more thermodynamically stable when an adenine residue was placed opposite 1,N⁶-γ-HMHP-dA instead of thymine, suggesting that these adducts may preferentially pair with dA.
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Affiliation(s)
- Uthpala Seneviratne
- Department of Chemistry, Department of Medicinal Chemistry, and Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA
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49
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Yuan B, Jiang Y, Wang Y, Wang Y. Efficient formation of the tandem thymine glycol/8-oxo-7,8-dihydroguanine lesion in isolated DNA and the mutagenic and cytotoxic properties of the tandem lesions in Escherichia coli cells. Chem Res Toxicol 2010; 23:11-9. [PMID: 20014805 DOI: 10.1021/tx9004264] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Reactive oxygen species can induce the formation of not only single-nucleobase lesions, which have been extensively studied, but also tandem lesions. Herein, we report a high frequency of formation of a type of tandem lesion, where two commonly observed oxidatively induced single-nucleobase lesions, that is, thymidine glycol (Tg) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), are vicinal to each other in calf thymus DNA upon exposure to Cu(II)/ascorbate along with H(2)O(2) or gamma-rays. We further explored how the tandem lesions perturb the efficiency and fidelity of DNA replication by assessing the replication products formed from the propagation, in Escherichia coli cells, of the single-stranded pYMV1 shuttle vectors containing two tandem lesions [5'-(8-oxodG)-Tg-3' and 5'-Tg-(8-oxodG)-3'] or an isolated Tg or 8-oxodG. The bypass efficiencies for the two tandem lesions were approximately one-half of those for the two isolated single-nucleobase lesions. The presence of an adjacent Tg could lead to significant increases in G-->T transversion at the 8-oxodG site as compared to that of a single 8-oxodG lesion; the frequencies of G-->T mutation were approximately 18, 32, and 28% for 8-oxodG that is isolated, in 5'-(8-oxodG)-Tg-3' and in 5'-Tg-(8-oxodG)-3', respectively. Moreover, both pol IV and pol V are involved, in part, in bypassing the Tg, either present alone or as part of the tandem lesions, in E. coli cells. Together, our results support that complex lesions could exert greater cytotoxic and mutagenic effects than when the composing individual lesions are present alone.
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Affiliation(s)
- Bifeng Yuan
- Department of Chemistry and, Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, USA
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50
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Huang H, Imoto S, Greenberg MM. The mutagenicity of thymidine glycol in Escherichia coli is increased when it is part of a tandem lesion. Biochemistry 2009; 48:7833-41. [PMID: 19618962 DOI: 10.1021/bi900927d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tandem lesions are comprised of two contiguously damaged nucleotides. Tandem lesions make up the major family of reaction products generated from a pyrimidine nucleobase radical, which are formed in large amounts by ionizing radiation. One of these tandem lesions contains a thymidine glycol lesion flanked on its 5'-side by 2-deoxyribonolactone (LTg). The replication of this tandem lesion was investigated in Escherichia coli using single-stranded genomes. LTg is a much more potent replication block than thymidine glycol and is bypassed only under SOS-induced conditions. The adjacent thymidine glycol does not significantly affect nucleotide incorporation opposite 2-deoxyribonolactone in wild-type cells. In contrast, the misinsertion frequency opposite thymidine glycol, which is negligible in the absence of 2-deoxyribonolactone, increases to 10% in wild-type cells when LTg is flanked by a 3'-dG. Experiments in which the flanking nucleotides are varied and in cells lacking one of the SOS-induced bypass polymerases indicate that the mutations are due to a mechanism in which the primer misaligns prior to bypassing the lesion, which allows for an additional nucleotide to be incorporated across from the 3'-flanking nucleotide. Subsequent realignment and extension results in the observed mutations. DNA polymerases II and IV are responsible for misalignment induced mutations and compete with DNA polymerase V which reads through the tandem lesion. These experiments reveal that incorporation of the thymidine glycol into a tandem lesion indirectly induces increases in mutations by blocking replication, which enables the misalignment-realignment mechanism to compete with direct bypass by DNA polymerase V.
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Affiliation(s)
- Haidong Huang
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
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