1
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Hussen AS, Kravitz HL, Freudenthal BD, Whitaker AM. Oxidative DNA damage on the VEGF G-quadruplex forming promoter is repaired via long-patch BER. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2024; 65 Suppl 1:25-39. [PMID: 37606505 PMCID: PMC10984112 DOI: 10.1002/em.22570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/01/2023] [Accepted: 08/20/2023] [Indexed: 08/23/2023]
Abstract
In response to oxidative damage, base excision repair (BER) enzymes perturb the structural equilibrium of the VEGF promoter between B-form and G4 DNA conformations, resulting in epigenetic-like modifications of gene expression. However, the mechanistic details remain enigmatic, including the activity and coordination of BER enzymes on the damaged G4 promoter. To address this, we investigated the ability of each BER factor to conduct its repair activity on VEGF promoter G4 DNA substrates by employing pre-steady-state kinetics assays and in vitro coupled BER assays. OGG1 was able to initiate BER on double-stranded VEGF promoter G4 DNA substrates. Moreover, pre-steady-state kinetics revealed that compared to B-form DNA, APE1 repair activity on the G4 was decreased ~two-fold and is the result of slower product release as opposed to inefficient strand cleavage. Interestingly, Pol β performs multiple insertions on G4 substrates via strand displacement DNA synthesis in contrast to a single insertion on B-form DNA. The multiple insertions inhibit ligation of the Pol β products, and hence BER is not completed on the VEGF G4 promoter substrates through canonical short-patch BER. Instead, repair requires the long-patch BER flap-endonuclease activity of FEN1 in response to the multiple insertions by Pol β prior to ligation. Because the BER proteins and their repair activities are a key part of the VEGF transcriptional enhancement in response to oxidative DNA damage of the G4 VEGF promoter, the new insights reported here on BER activity in the context of this promoter are relevant toward understanding the mechanism of transcriptional regulation.
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Affiliation(s)
- Adil S. Hussen
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Haley L. Kravitz
- Nuclear Dynamics and Cancer Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
| | - Bret D. Freudenthal
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Amy M. Whitaker
- Nuclear Dynamics and Cancer Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
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2
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Kruchinin AA, Kamzeeva PN, Zharkov DO, Aralov AV, Makarova AV. 8-Oxoadenine: A «New» Player of the Oxidative Stress in Mammals? Int J Mol Sci 2024; 25:1342. [PMID: 38279342 PMCID: PMC10816367 DOI: 10.3390/ijms25021342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/13/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024] Open
Abstract
Numerous studies have shown that oxidative modifications of guanine (7,8-dihydro-8-oxoguanine, 8-oxoG) can affect cellular functions. 7,8-Dihydro-8-oxoadenine (8-oxoA) is another abundant paradigmatic ambiguous nucleobase but findings reported on the mutagenicity of 8-oxoA in bacterial and eukaryotic cells are incomplete and contradictory. Although several genotoxic studies have demonstrated the mutagenic potential of 8-oxoA in eukaryotic cells, very little biochemical and bioinformatics data about the mechanism of 8-oxoA-induced mutagenesis are available. In this review, we discuss dual coding properties of 8-oxoA, summarize historical and recent genotoxicity and biochemical studies, and address the main protective cellular mechanisms of response to 8-oxoA. We also discuss the available structural data for 8-oxoA bypass by different DNA polymerases as well as the mechanisms of 8-oxoA recognition by DNA repair enzymes.
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Affiliation(s)
- Alexander A. Kruchinin
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova St., 119334 Moscow, Russia; (A.A.K.); (P.N.K.)
- National Research Center, Kurchatov Institute, Kurchatov sq. 2, 123182 Moscow, Russia
| | - Polina N. Kamzeeva
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova St., 119334 Moscow, Russia; (A.A.K.); (P.N.K.)
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia;
| | - Dmitry O. Zharkov
- Department of Natural Sciences, Novosibirsk State University, 1 Pirogova St., 630090 Novosibirsk, Russia;
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Andrey V. Aralov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia;
| | - Alena V. Makarova
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova St., 119334 Moscow, Russia; (A.A.K.); (P.N.K.)
- National Research Center, Kurchatov Institute, Kurchatov sq. 2, 123182 Moscow, Russia
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3
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Dong JH, Zhang RH, Zhao LL, Xue CY, Pan HY, Zhong XY, Zhou YL, Zhang XX. Identification and Quantification of Locus-Specific 8-Oxo-7,8-dihydroguanine in DNA at Ultrahigh Resolution Based on G-Triplex-Assisted Rolling Circle Amplification. Anal Chem 2024; 96:437-445. [PMID: 38150621 DOI: 10.1021/acs.analchem.3c04498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Damage of reactive oxygen species to various molecules such as DNA has been related to many chronic and degenerative human diseases, aging, and even cancer. 8-Oxo-7,8-dihydroguanine (OG), the most significant oxidation product of guanine (G), has become a biomarker of oxidative stress as well as gene regulation. The positive effect of OG in activating transcription and the negative effect in inducing mutation are a double-edged sword; thus, site-specific quantification is helpful to quickly reveal the functional mechanism of OG at hotspots. Due to the possible biological effects of OG at extremely low abundance in the genome, the monitoring of OG is vulnerable to signal interference from a large amount of G. Herein, based on rolling circle amplification-induced G-triplex formation and Thioflavin T fluorescence enhancement, an ultrasensitive strategy for locus-specific OG quantification was constructed. Owing to the difference in the hydrogen-bonding pattern between OG and G, the nonspecific background signal of G sites was completely suppressed through enzymatic ligation of DNA probes and the triggered specificity of rolling circle amplification. After the signal amplification strategy was optimized, the high detection sensitivity of OG sites with an ultralow detection limit of 0.18 amol was achieved. Under the interference of G sites, as little as 0.05% of OG-containing DNA was first distinguished. This method was further used for qualitative and quantitative monitoring of locus-specific OG in genomic DNA under oxidative stress and identification of key OG sites with biological function.
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Affiliation(s)
- Jia-Hui Dong
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Run-Hong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Ling-Li Zhao
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Chen-Yu Xue
- Key Laboratory of Forensic Toxicology, Ministry of Public Security, Beijing 100191, China
| | - Hui-Yu Pan
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xin-Ying Zhong
- Central Research Institute, Shanghai Pharmaceuticals Holding Co., Ltd., Shanghai 201203, China
| | - Ying-Lin Zhou
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xin-Xiang Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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4
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Rodriguez-Colman MJ, Dansen TB, Burgering BMT. FOXO transcription factors as mediators of stress adaptation. Nat Rev Mol Cell Biol 2024; 25:46-64. [PMID: 37710009 DOI: 10.1038/s41580-023-00649-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2023] [Indexed: 09/16/2023]
Abstract
The forkhead box protein O (FOXO, consisting of FOXO1, FOXO3, FOXO4 and FOXO6) transcription factors are the mammalian orthologues of Caenorhabditis elegans DAF-16, which gained notoriety for its capability to double lifespan in the absence of daf-2 (the gene encoding the worm insulin receptor homologue). Since then, research has provided many mechanistic details on FOXO regulation and FOXO activity. Furthermore, conditional knockout experiments have provided a wealth of data as to how FOXOs control development and homeostasis at the organ and organism levels. The lifespan-extending capabilities of DAF-16/FOXO are highly correlated with their ability to induce stress response pathways. Exogenous and endogenous stress, such as cellular redox stress, are considered the main drivers of the functional decline that characterizes ageing. Functional decline often manifests as disease, and decrease in FOXO activity indeed negatively impacts on major age-related diseases such as cancer and diabetes. In this context, the main function of FOXOs is considered to preserve cellular and organismal homeostasis, through regulation of stress response pathways. Paradoxically, the same FOXO-mediated responses can also aid the survival of dysfunctional cells once these eventually emerge. This general property to control stress responses may underlie the complex and less-evident roles of FOXOs in human lifespan as opposed to model organisms such as C. elegans.
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Affiliation(s)
| | - Tobias B Dansen
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Boudewijn M T Burgering
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands.
- Oncode Institute, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands.
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5
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Sarmini L, Meabed M, Emmanouil E, Atsaves G, Robeska E, Karwowski BT, Campalans A, Gimisis T, Khobta A. Requirement of transcription-coupled nucleotide excision repair for the removal of a specific type of oxidatively induced DNA damage. Nucleic Acids Res 2023; 51:4982-4994. [PMID: 37026475 PMCID: PMC10250225 DOI: 10.1093/nar/gkad256] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 03/06/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023] Open
Abstract
Accumulation of DNA damage resulting from reactive oxygen species was proposed to cause neurological and degenerative disease in patients, deficient in nucleotide excision repair (NER) or its transcription-coupled subpathway (TC-NER). Here, we assessed the requirement of TC-NER for the repair of specific types of oxidatively generated DNA modifications. We incorporated synthetic 5',8-cyclo-2'-deoxypurine nucleotides (cyclo-dA, cyclo-dG) and thymine glycol (Tg) into an EGFP reporter gene to measure transcription-blocking potentials of these modifications in human cells. Using null mutants, we further identified the relevant DNA repair components by a host cell reactivation approach. The results indicated that NTHL1-initiated base excision repair is by far the most efficient pathway for Tg. Moreover, Tg was efficiently bypassed during transcription, which effectively rules out TC-NER as an alternative repair mechanism. In a sharp contrast, both cyclopurine lesions robustly blocked transcription and were repaired by NER, wherein the specific TC-NER components CSB/ERCC6 and CSA/ERCC8 were as essential as XPA. Instead, repair of classical NER substrates, cyclobutane pyrimidine dimer and N-(deoxyguanosin-8-yl)-2-acetylaminofluorene, occurred even when TC-NER was disrupted. The strict requirement of TC-NER highlights cyclo-dA and cyclo-dG as candidate damage types, accountable for cytotoxic and degenerative responses in individuals affected by genetic defects in this pathway.
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Affiliation(s)
- Leen Sarmini
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, Jena 07743, Germany
| | - Mohammed Meabed
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, Jena 07743, Germany
| | - Eirini Emmanouil
- Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - George Atsaves
- Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Elena Robeska
- Université Paris-Saclay, CEA/IBFJ/IRCM. UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, F-92265, France
- Université de Paris Cité, CEA/IBFJ/IRCM. UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, F-92265, France
| | - Bolesław T Karwowski
- DNA Damage Laboratory of Food Science Department, Faculty of Pharmacy, Medical University of Lodz, Lodz 90-151, Poland
| | - Anna Campalans
- Université Paris-Saclay, CEA/IBFJ/IRCM. UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, F-92265, France
- Université de Paris Cité, CEA/IBFJ/IRCM. UMR Stabilité Génétique Cellules Souches et Radiations, Fontenay-aux-Roses, F-92265, France
| | - Thanasis Gimisis
- Department of Chemistry, National and Kapodistrian University of Athens, Athens 15771, Greece
| | - Andriy Khobta
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, Jena 07743, Germany
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6
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OGG1 in the Kidney: Beyond Base Excision Repair. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:5774641. [PMID: 36620083 PMCID: PMC9822757 DOI: 10.1155/2022/5774641] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 01/01/2023]
Abstract
8-Oxoguanine DNA glycosylase (OGG1) is a repair protein for 8-oxoguanine (8-oxoG) in eukaryotic atopic DNA. Through the initial base excision repair (BER) pathway, 8-oxoG is recognized and excised, and subsequently, other proteins are recruited to complete the repair. OGG1 is primarily located in the cytoplasm and can enter the nucleus and mitochondria to repair damaged DNA or to exert epigenetic regulation of gene transcription. OGG1 is involved in a wide range of physiological processes, such as DNA repair, oxidative stress, inflammation, fibrosis, and autophagy. In recent years, studies have found that OGG1 plays an important role in the progression of kidney diseases through repairing DNA, inducing inflammation, regulating autophagy and other transcriptional regulation, and governing protein interactions and functions during disease and injury. In particular, the epigenetic effects of OGG1 in kidney disease have gradually attracted widespread attention. This study reviews the structure and biological functions of OGG1 and the regulatory mechanism of OGG1 in kidney disease. In addition, the possibility of OGG1 as a potential therapeutic target in kidney disease is discussed.
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7
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Hahm JY, Park J, Jang ES, Chi SW. 8-Oxoguanine: from oxidative damage to epigenetic and epitranscriptional modification. Exp Mol Med 2022; 54:1626-1642. [PMID: 36266447 PMCID: PMC9636213 DOI: 10.1038/s12276-022-00822-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/06/2022] [Accepted: 05/26/2022] [Indexed: 12/29/2022] Open
Abstract
In pathophysiology, reactive oxygen species control diverse cellular phenotypes by oxidizing biomolecules. Among these, the guanine base in nucleic acids is the most vulnerable to producing 8-oxoguanine, which can pair with adenine. Because of this feature, 8-oxoguanine in DNA (8-oxo-dG) induces a G > T (C > A) mutation in cancers, which can be deleterious and thus actively repaired by DNA repair pathways. 8-Oxoguanine in RNA (o8G) causes problems in aberrant quality and translational fidelity, thereby it is subjected to the RNA decay pathway. In addition to oxidative damage, 8-oxo-dG serves as an epigenetic modification that affects transcriptional regulatory elements and other epigenetic modifications. With the ability of o8G•A in base pairing, o8G alters structural and functional RNA-RNA interactions, enabling redirection of posttranscriptional regulation. Here, we address the production, regulation, and function of 8-oxo-dG and o8G under oxidative stress. Primarily, we focus on the epigenetic and epitranscriptional roles of 8-oxoguanine, which highlights the significance of oxidative modification in redox-mediated control of gene expression.
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Affiliation(s)
- Ja Young Hahm
- grid.222754.40000 0001 0840 2678Department of Life Sciences, Korea University, Seoul, 02481 Republic of Korea ,grid.222754.40000 0001 0840 2678Institute of Life Sciences and Biotechnology, Korea University, Seoul, 02481 Republic of Korea
| | - Jongyeun Park
- grid.222754.40000 0001 0840 2678Department of Life Sciences, Korea University, Seoul, 02481 Republic of Korea ,grid.222754.40000 0001 0840 2678Institute of Life Sciences and Biotechnology, Korea University, Seoul, 02481 Republic of Korea
| | - Eun-Sook Jang
- grid.222754.40000 0001 0840 2678Department of Life Sciences, Korea University, Seoul, 02481 Republic of Korea ,grid.222754.40000 0001 0840 2678Institute of Life Sciences and Biotechnology, Korea University, Seoul, 02481 Republic of Korea
| | - Sung Wook Chi
- grid.222754.40000 0001 0840 2678Department of Life Sciences, Korea University, Seoul, 02481 Republic of Korea ,grid.222754.40000 0001 0840 2678Institute of Life Sciences and Biotechnology, Korea University, Seoul, 02481 Republic of Korea ,grid.222754.40000 0001 0840 2678KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02481 Republic of Korea
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8
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Konis SMR, Hughes JR, Parsons JL. TRIM26 Maintains Cell Survival in Response to Oxidative Stress through Regulating DNA Glycosylase Stability. Int J Mol Sci 2022; 23:ijms231911613. [PMID: 36232914 PMCID: PMC9569934 DOI: 10.3390/ijms231911613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/16/2022] Open
Abstract
Oxidative DNA base lesions in DNA are repaired through the base excision repair (BER) pathway, which consequently plays a vital role in the maintenance of genome integrity and in suppressing mutagenesis. 8-oxoguanine DNA glycosylase (OGG1), endonuclease III-like protein 1 (NTH1), and the endonuclease VIII-like proteins 1-3 (NEIL1-3) are the key enzymes that initiate repair through the excision of the oxidized base. We have previously identified that the E3 ubiquitin ligase tripartite motif 26 (TRIM26) controls the cellular response to oxidative stress through regulating both NEIL1 and NTH1, although its potential, broader role in BER is unclear. We now show that TRIM26 is a central player in determining the response to different forms of oxidative stress. Using siRNA-mediated knockdowns, we demonstrate that the resistance of cells to X-ray radiation and hydrogen peroxide generated as a consequence of trim26 depletion can be reversed through suppression of selective DNA glycosylases. In particular, a knockdown of neil1 or ogg1 can enhance sensitivity and DNA repair rates in response to X-rays, whereas a knockdown of neil1 or neil3 can produce the same effect in response to hydrogen peroxide. Our study, therefore, highlights the importance of TRIM26 in balancing cellular DNA glycosylase levels required for an efficient BER response.
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Affiliation(s)
- Sifaddin M. R. Konis
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool, 6 West Derby Street, Liverpool L7 8TX, UK
| | - Jonathan R. Hughes
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool, 6 West Derby Street, Liverpool L7 8TX, UK
| | - Jason L. Parsons
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool, 6 West Derby Street, Liverpool L7 8TX, UK
- Clatterbridge Cancer Centre NHS Foundation Trust, Clatterbridge Road, Bebington CH63 4JY, UK
- Correspondence: ; Tel.: +44-151-794-8848
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9
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Oliveira TT, Coutinho LG, de Oliveira LOA, Timoteo ARDS, Farias GC, Agnez-Lima LF. APE1/Ref-1 Role in Inflammation and Immune Response. Front Immunol 2022; 13:793096. [PMID: 35296074 PMCID: PMC8918667 DOI: 10.3389/fimmu.2022.793096] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 02/07/2022] [Indexed: 12/12/2022] Open
Abstract
Apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional enzyme that is essential for maintaining cellular homeostasis. APE1 is the major apurinic/apyrimidinic endonuclease in the base excision repair pathway and acts as a redox-dependent regulator of several transcription factors, including NF-κB, AP-1, HIF-1α, and STAT3. These functions render APE1 vital to regulating cell signaling, senescence, and inflammatory pathways. In addition to regulating cytokine and chemokine expression through activation of redox sensitive transcription factors, APE1 participates in other critical processes in the immune response, including production of reactive oxygen species and class switch recombination. Furthermore, through participation in active chromatin demethylation, the repair function of APE1 also regulates transcription of some genes, including cytokines such as TNFα. The multiple functions of APE1 make it an essential regulator of the pathogenesis of several diseases, including cancer and neurological disorders. Therefore, APE1 inhibitors have therapeutic potential. APE1 is highly expressed in the central nervous system (CNS) and participates in tissue homeostasis, and its roles in neurodegenerative and neuroinflammatory diseases have been elucidated. This review discusses known roles of APE1 in innate and adaptive immunity, especially in the CNS, recent evidence of a role in the extracellular environment, and the therapeutic potential of APE1 inhibitors in infectious/immune diseases.
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Affiliation(s)
- Thais Teixeira Oliveira
- Departamento de Biologia Celular e Genética, Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil
| | - Leonam Gomes Coutinho
- Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte (IFRN), São Paulo do Potengi, Brazil
| | | | | | - Guilherme Cavalcanti Farias
- Departamento de Biologia Celular e Genética, Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil
| | - Lucymara Fassarella Agnez-Lima
- Departamento de Biologia Celular e Genética, Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil
- *Correspondence: Lucymara Fassarella Agnez-Lima,
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10
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Endutkin AV, Yatsenko DD, Zharkov DO. Effect of DNA Methylation on the 3'→5' Exonuclease Activity of Major Human Abasic Site Endonuclease APEX1. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:10-20. [PMID: 35491018 DOI: 10.1134/s0006297922010023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Apurinic/apyrimidinic (AP) endonucleases are the key enzymes in the DNA base excision repair, as they hydrolyze the phosphodiester bond in the AP site formed after removal of the damaged base. Major human AP endonuclease APEX1 also possesses the 3'-phosphodiesterase and 3'→5' exonuclease activities. The biological role of the latter has not been established yet; it is assumed that it corrects DNA synthesis errors during DNA repair. If DNA is damaged at the 3'-side of 5-methylcytosine (mC) residue, the 3'→5' exonuclease activity can change the epigenetic methylation status of the CpG dinucleotide. It remains unclear whether the 3'→5' exonuclease activity of APEX1 contributes to the active epigenetic demethylation or, on the contrary, is limited in the case of methylated CpG dinucleotides in order to preserve the epigenetic status upon repair of accidental DNA damage. Here, we report the results of the first systematic study on the efficiency of removal of 3'-terminal nucleotides from the substrates modeling DNA repair intermediates in the CpG dinucleotides. The best substrates for the 3'→5' exonuclease activity of APEX1 were oligonucleotides with the 3'-terminal bases non-complementary to the template, while the worst substrates contained mC. The presence of mC in the complementary strand significantly reduced the reaction rate even for the non-complementary 3'-ends. Therefore, the efficiency of the 3'→5' exonuclease reaction catalyzed by APEX1 is limited in the case of the methylated CpG dinucleotides, which likely reflects the need to preserve the epigenetic status during DNA repair.
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Affiliation(s)
- Anton V Endutkin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Darya D Yatsenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Dmitry O Zharkov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk, 630090, Russia
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11
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Direct and Base Excision Repair-Mediated Regulation of a GC-Rich cis-Element in Response to 5-Formylcytosine and 5-Carboxycytosine. Int J Mol Sci 2021; 22:ijms222011025. [PMID: 34681690 PMCID: PMC8539351 DOI: 10.3390/ijms222011025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 11/25/2022] Open
Abstract
Stepwise oxidation of the epigenetic mark 5-methylcytosine and base excision repair (BER) of the resulting 5-formylcytosine (5-fC) and 5-carboxycytosine (5-caC) may provide a mechanism for reactivation of epigenetically silenced genes; however, the functions of 5-fC and 5-caC at defined gene elements are scarcely explored. We analyzed the expression of reporter constructs containing either 2′-deoxy-(5-fC/5-caC) or their BER-resistant 2′-fluorinated analogs, asymmetrically incorporated into CG-dinucleotide of the GC box cis-element (5′-TGGGCGGAGC) upstream from the RNA polymerase II core promoter. In the absence of BER, 5-caC caused a strong inhibition of the promoter activity, whereas 5-fC had almost no effect, similar to 5-methylcytosine or 5-hydroxymethylcytosine. BER of 5-caC caused a transient but significant promoter reactivation, succeeded by silencing during the following hours. Both responses strictly required thymine DNA glycosylase (TDG); however, the silencing phase additionally demanded a 5′-endonuclease (likely APE1) activity and was also induced by 5-fC or an apurinic/apyrimidinic site. We propose that 5-caC may act as a repressory mark to prevent premature activation of promoters undergoing the final stages of DNA demethylation, when the symmetric CpG methylation has already been lost. Remarkably, the downstream promoter activation or repression responses are regulated by two separate BER steps, where TDG and APE1 act as potential switches.
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12
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Effects of Manganese on Genomic Integrity in the Multicellular Model Organism Caenorhabditis elegans. Int J Mol Sci 2021; 22:ijms222010905. [PMID: 34681565 PMCID: PMC8535284 DOI: 10.3390/ijms222010905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 09/24/2021] [Accepted: 09/30/2021] [Indexed: 12/30/2022] Open
Abstract
Although manganese (Mn) is an essential trace element, overexposure is associated with Mn-induced toxicity and neurological dysfunction. Even though Mn-induced oxidative stress is discussed extensively, neither the underlying mechanisms of the potential consequences of Mn-induced oxidative stress on DNA damage and DNA repair, nor the possibly resulting toxicity are characterized yet. In this study, we use the model organism Caenorhabditis elegans to investigate the mode of action of Mn toxicity, focusing on genomic integrity by means of DNA damage and DNA damage response. Experiments were conducted to analyze Mn bioavailability, lethality, and induction of DNA damage. Different deletion mutant strains were then used to investigate the role of base excision repair (BER) and dePARylation (DNA damage response) proteins in Mn-induced toxicity. The results indicate a dose- and time-dependent uptake of Mn, resulting in increased lethality. Excessive exposure to Mn decreases genomic integrity and activates BER. Altogether, this study characterizes the consequences of Mn exposure on genomic integrity and therefore broadens the molecular understanding of pathways underlying Mn-induced toxicity. Additionally, studying the basal poly(ADP-ribosylation) (PARylation) of worms lacking poly(ADP-ribose) glycohydrolase (PARG) parg-1 or parg-2 (two orthologue of PARG), indicates that parg-1 accounts for most of the glycohydrolase activity in worms.
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13
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Burchat N, Sharma P, Ye H, Komakula SSB, Dobrzyn A, Vartanian V, Lloyd RS, Sampath H. Maternal Transmission of Human OGG1 Protects Mice Against Genetically- and Diet-Induced Obesity Through Increased Tissue Mitochondrial Content. Front Cell Dev Biol 2021; 9:718962. [PMID: 34604220 PMCID: PMC8480284 DOI: 10.3389/fcell.2021.718962] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/09/2021] [Indexed: 01/05/2023] Open
Abstract
Obesity and related metabolic disorders are pressing public health concerns, raising the risk for a multitude of chronic diseases. Obesity is multi-factorial disease, with both diet and lifestyle, as well as genetic and developmental factors leading to alterations in energy balance. In this regard, a novel role for DNA repair glycosylases in modulating risk for obesity has been previously established. Global deletion of either of two different glycosylases with varying substrate specificities, Nei-like endonuclease 1 (NEIL1) or 8-oxoguanine DNA glycosylase-1 (OGG1), both predispose mice to diet-induced obesity (DIO). Conversely, enhanced expression of the human OGG1 gene renders mice resistant to obesity and adiposity. This resistance to DIO is mediated through increases in whole body energy expenditure and increased respiration in adipose tissue. Here, we report that hOGG1 expression also confers resistance to genetically-induced obesity. While Agouti obese (Ay/a) mice are hyperphagic and consequently develop obesity on a chow diet, hOGG1 expression in Ay/a mice (Ay/aTg) prevents increased body weight, without reducing food intake. Instead, obesity resistance in Ay/aTg mice is accompanied by increased whole body energy expenditure and tissue mitochondrial content. We also report for the first time that OGG1-mediated obesity resistance in both the Ay/a model and DIO model requires maternal transmission of the hOGG1 transgene. Maternal, but not paternal, transmission of the hOGG1 transgene is associated with obesity resistance and increased mitochondrial content in adipose tissue. These data demonstrate a critical role for OGG1 in modulating energy balance through changes in adipose tissue function. They also demonstrate the importance of OGG1 in modulating developmental programming of mitochondrial content and quality, thereby determining metabolic outcomes in offspring.
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Affiliation(s)
- Natalie Burchat
- Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, United States
| | - Priyanka Sharma
- Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, United States
| | - Hong Ye
- Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, United States
| | - Sai Santosh Babu Komakula
- Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, United States.,Laboratory of Cell Signaling and Metabolic Disorders, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Agnieszka Dobrzyn
- Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, United States.,Laboratory of Cell Signaling and Metabolic Disorders, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Vladimir Vartanian
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR, United States
| | - R Stephen Lloyd
- Oregon Institute of Occupational Health Sciences, Oregon Health and Science University, Portland, OR, United States.,Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, United States
| | - Harini Sampath
- Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, United States.,Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ, United States.,Center for Microbiome, Nutrition, and Health, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, United States
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14
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Fleming AM, Burrows CJ. Oxidative stress-mediated epigenetic regulation by G-quadruplexes. NAR Cancer 2021; 3:zcab038. [PMID: 34541539 PMCID: PMC8445369 DOI: 10.1093/narcan/zcab038] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/20/2021] [Accepted: 09/06/2021] [Indexed: 02/06/2023] Open
Abstract
Many cancer-associated genes are regulated by guanine (G)-rich sequences that are capable of refolding from the canonical duplex structure to an intrastrand G-quadruplex. These same sequences are sensitive to oxidative damage that is repaired by the base excision repair glycosylases OGG1 and NEIL1–3. We describe studies indicating that oxidation of a guanosine base in a gene promoter G-quadruplex can lead to up- and downregulation of gene expression that is location dependent and involves the base excision repair pathway in which the first intermediate, an apurinic (AP) site, plays a key role mediated by AP endonuclease 1 (APE1/REF1). The nuclease activity of APE1 is paused at a G-quadruplex, while the REF1 capacity of this protein engages activating transcription factors such as HIF-1α, AP-1 and p53. The mechanism has been probed by in vitro biophysical studies, whole-genome approaches and reporter plasmids in cellulo. Replacement of promoter elements by a G-quadruplex sequence usually led to upregulation, but depending on the strand and precise location, examples of downregulation were also found. The impact of oxidative stress-mediated lesions in the G-rich sequence enhanced the effect, whether it was positive or negative.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry, University of Utah, 315 S. 1400 East, Salt Lake City, UT 84112-0850, USA
| | - Cynthia J Burrows
- Department of Chemistry, University of Utah, 315 S. 1400 East, Salt Lake City, UT 84112-0850, USA
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15
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Chao MR, Evans MD, Hu CW, Ji Y, Møller P, Rossner P, Cooke MS. Biomarkers of nucleic acid oxidation - A summary state-of-the-art. Redox Biol 2021; 42:101872. [PMID: 33579665 PMCID: PMC8113048 DOI: 10.1016/j.redox.2021.101872] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 12/12/2022] Open
Abstract
Oxidatively generated damage to DNA has been implicated in the pathogenesis of a wide variety of diseases. Increasingly, interest is also focusing upon the effects of damage to the other nucleic acids, RNA and the (2′-deoxy-)ribonucleotide pools, and evidence is growing that these too may have an important role in disease. LC-MS/MS has the ability to provide absolute quantification of specific biomarkers, such as 8-oxo-7,8-dihydro-2′-deoxyGuo (8-oxodG), in both nuclear and mitochondrial DNA, and 8-oxoGuo in RNA. However, significant quantities of tissue are needed, limiting its use in human biomonitoring studies. In contrast, the comet assay requires much less material, and as little as 5 μL of blood may be used, offering a minimally invasive means of assessing oxidative stress in vivo, but this is restricted to nuclear DNA damage only. Urine is an ideal matrix in which to non-invasively study nucleic acid-derived biomarkers of oxidative stress, and considerable progress has been made towards robustly validating these measurements, not least through the efforts of the European Standards Committee on Urinary (DNA) Lesion Analysis. For urine, LC-MS/MS is considered the gold standard approach, and although there have been improvements to the ELISA methodology, this is largely limited to 8-oxodG. Emerging DNA adductomics approaches, which either comprehensively assess the totality of adducts in DNA, or map DNA damage across the nuclear and mitochondrial genomes, offer the potential to considerably advance our understanding of the mechanistic role of oxidatively damaged nucleic acids in disease. Oxidatively damaged nucleic acids are implicated in the pathogenesis of disease. LC-MS/MS, comet assay and ELISA are often used to study oxidatively damaged DNA. Urinary oxidatively damaged nucleic acids non-invasively reflect oxidative stress. DNA adductomics will aid understanding the role of ROS damaged DNA in disease.
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Affiliation(s)
- Mu-Rong Chao
- Department of Occupational Safety and Health, Chung Shan Medical University, Taichung, 402, Taiwan; Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung, 402, Taiwan
| | - Mark D Evans
- Leicester School of Allied Health Sciences, Faculty of Health & Life Sciences, De Montfort University, The Gateway, Leicester, LE1 9BH, United Kingdom
| | - Chiung-Wen Hu
- Department of Public Health, Chung Shan Medical University, Taichung, 402, Taiwan
| | - Yunhee Ji
- Department of Environmental Health Sciences, Florida International University, Miami, FL, 33199, USA
| | - Peter Møller
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Øster Farimagsgade 5A, DK, 1014, Copenhagen K, Denmark
| | - Pavel Rossner
- Department of Nanotoxicology and Molecular Epidemiology, Institute of Experimental Medicine of the CAS, 142 20, Prague, Czech Republic
| | - Marcus S Cooke
- Oxidative Stress Group, Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, 33620, USA.
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16
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Fleming AM, Zhu J, Jara-Espejo M, Burrows CJ. Cruciform DNA Sequences in Gene Promoters Can Impact Transcription upon Oxidative Modification of 2'-Deoxyguanosine. Biochemistry 2020; 59:2616-2626. [PMID: 32567845 DOI: 10.1021/acs.biochem.0c00387] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sequences of DNA typically adopt B-form duplexes in genomes, although noncanonical structures such as G-quadruplexes, i-motifs, Z-DNA, and cruciform structures can occur. A challenge is to determine the functions of these various structures in cellular processes. We and others have hypothesized that G-rich G-quadruplex-forming sequences in human genome promoters serve to sense oxidative damage generated during oxidative stress impacting gene regulation. Herein, chemical tools and a cell-based assay were used to study the oxidation of guanine to 8-oxo-7,8-dihydroguanine (OG) in the context of a cruciform-forming sequence in a gene promoter to determine the impact on transcription. We found that OG in the nontemplate strand in the loop of a cruciform-forming sequence could induce gene expression; conversely when OG was in the same sequence on the template strand, gene expression was inhibited. A model for the transcriptional changes observed is proposed in which OG focuses the DNA repair process on the promoter to impact expression. Our cellular and biophysical studies and literature sources support the idea that removal of OG from duplex DNA by OGG1 yields an abasic site (AP) that triggers a structural shift to the cruciform fold. The AP-bearing cruciform structure is presented to APE1, which functions as a conduit between DNA repair and gene regulation. The significance is enhanced by a bioinformatic study of all human gene promoters and transcription termination sites for inverted repeats (IRs). Comparison of the two regions showed that promoters have stable and G-rich IRs at a low frequency and termination sites have many AT-rich IRs with low stability.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - Judy Zhu
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - Manuel Jara-Espejo
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States.,Department of Morphology, Piracicaba Dental School, University of Campinas-UNICAMP, Av. Limeira 901, Piracicaba, CEP 13414-018 Sao Paulo, Brazil
| | - Cynthia J Burrows
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
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17
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Rodriguez-Alvarez M, Kim D, Khobta A. EGFP Reporters for Direct and Sensitive Detection of Mutagenic Bypass of DNA Lesions. Biomolecules 2020; 10:biom10060902. [PMID: 32545792 PMCID: PMC7357151 DOI: 10.3390/biom10060902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/05/2020] [Accepted: 06/10/2020] [Indexed: 02/06/2023] Open
Abstract
The sustainment of replication and transcription of damaged DNA is essential for cell survival under genotoxic stress; however, the damage tolerance of these key cellular functions comes at the expense of fidelity. Thus, translesion DNA synthesis (TLS) over damaged nucleotides is a major source of point mutations found in cancers; whereas erroneous bypass of damage by RNA polymerases may contribute to cancer and other diseases by driving accumulation of proteins with aberrant structure and function in a process termed “transcriptional mutagenesis” (TM). Here, we aimed at the generation of reporters suited for direct detection of miscoding capacities of defined types of DNA modifications during translesion DNA or RNA synthesis in human cells. We performed a systematic phenotypic screen of 25 non-synonymous base substitutions in a DNA sequence encoding a functionally important region of the enhanced green fluorescent protein (EGFP). This led to the identification of four loss-of-fluorescence mutants, in which any ulterior base substitution at the nucleotide affected by the primary mutation leads to the reversal to a functional EGFP. Finally, we incorporated highly mutagenic abasic DNA lesions at the positions of primary mutations and demonstrated a high sensitivity of detection of the mutagenic DNA TLS and TM in this system.
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Affiliation(s)
- Marta Rodriguez-Alvarez
- Unit “Responses to DNA Lesions", Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher Str. 67, 55131 Mainz, Germany;
| | - Daria Kim
- Novosibirsk State University, 1 Pirogova St., 630090 Novosibirsk, Russia;
- Laboratory of Genome and Protein Engineering, SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia
| | - Andriy Khobta
- Unit “Responses to DNA Lesions", Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Obere Zahlbacher Str. 67, 55131 Mainz, Germany;
- Correspondence:
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18
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Hao W, Wang J, Zhang Y, Wang C, Xia L, Zhang W, Zafar M, Kang JY, Wang R, Ali Bohio A, Pan L, Zeng X, Wei M, Boldogh I, Ba X. Enzymatically inactive OGG1 binds to DNA and steers base excision repair toward gene transcription. FASEB J 2020; 34:7427-7441. [PMID: 32378256 PMCID: PMC7318607 DOI: 10.1096/fj.201902243r] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/19/2019] [Accepted: 03/17/2020] [Indexed: 12/11/2022]
Abstract
8‐Oxoguanine DNA glycosylase1 (OGG1)‐initiated base excision repair (BER) is the primary pathway to remove the pre‐mutagenic 8‐oxo‐7,8‐dihydroguanine (8‐oxoG) from DNA. Recent studies documented 8‐oxoG serves as an epigenetic‐like mark and OGG1 modulates gene expression in oxidatively stressed cells. For this new role of OGG1, two distinct mechanisms have been proposed: one is coupled to base excision, while the other only requires substrate binding of OGG1––both resulting in conformational adjustment in the adjacent DNA sequences providing access for transcription factors to their cis‐elements. The present study aimed to examine if BER activity of OGG1 is required for pro‐inflammatory gene expression. To this end, Ogg1/OGG1 knockout/depleted cells were transfected with constructs expressing wild‐type (wt) and repair‐deficient mutants of OGG1. OGG1's promoter enrichment, oxidative state, and gene expression were examined. Results showed that TNFα exposure increased levels of oxidatively modified cysteine(s) of wt OGG1 without impairing its association with promoter and facilitated gene expression. The excision deficient K249Q mutant was even a more potent activator of gene expression; whereas, mutant OGG1 with impaired substrate recognition/binding was not. These data suggested the interaction of OGG1 with its substrate at regulatory regions followed by conformational adjustment in the adjacent DNA is the primary mode to modulate inflammatory gene expression.
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Affiliation(s)
- Wenjing Hao
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Jing Wang
- Department of Respiratory Medicine, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Yuanhang Zhang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Chenxin Wang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Lan Xia
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Wenhe Zhang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Muhammad Zafar
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Ju-Yong Kang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,Faculty of Life Science, Kim Il Sung University, Pyongyang, DPRK
| | - Ruoxi Wang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China.,Key Laboratory of Animal Resistance Biology of Shandong Province, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Ameer Ali Bohio
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Lang Pan
- School of Life Science, Northeast Normal University, Changchun, China.,Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Xianlu Zeng
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Min Wei
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Xueqing Ba
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, China.,School of Life Science, Northeast Normal University, Changchun, China
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19
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Yang H, Tang JA, Greenberg MM. Synthesis of Oligonucleotides Containing the N 6 -(2-Deoxy-α,β-d-erythropentofuranosyl)-2,6-diamino-4-hydroxy-5-formamidopyrimidine (Fapy⋅dG) Oxidative Damage Product Derived from 2'-Deoxyguanosine. Chemistry 2020; 26:5441-5448. [PMID: 32271495 DOI: 10.1002/chem.201905795] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Indexed: 12/19/2022]
Abstract
N6 -(2-Deoxy-α,β-d-erythropentofuranosyl)-2,6-diamino-4-hydroxy-5-formamidopyrimidine (Fapy⋅dG) is a major DNA lesion produced from 2'-deoxyguanosine under oxidizing conditions. Fapy⋅dG is produced from a common intermediate that leads to 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-OxodGuo), and in greater quantities in cells. The impact of Fapy⋅dG on DNA structure and function is much less well understood than that of 8-OxodGuo. This is largely due to the significantly greater difficulty in synthesizing oligonucleotides containing Fapy⋅dG than 8-OxodGuo. We describe a synthetic approach for preparing oligonucleotides containing Fapy⋅dG that will facilitate intensive studies of this lesion in DNA. A variety of oligonucleotides as long as 30 nucleotides are synthesized. We anticipate that the chemistry described herein will provide an impetus for a wide range of studies involving Fapy⋅dG.
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Affiliation(s)
- Haozhe Yang
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Joel A Tang
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Marc M Greenberg
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
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20
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Fleming AM, Burrows CJ. Interplay of Guanine Oxidation and G-Quadruplex Folding in Gene Promoters. J Am Chem Soc 2020; 142:1115-1136. [PMID: 31880930 PMCID: PMC6988379 DOI: 10.1021/jacs.9b11050] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Living in an oxygen atmosphere demands an ability to thrive in the presence of reactive oxygen species (ROS). Aerobic organisms have successfully found solutions to the oxidative threats imposed by ROS by evolving an elaborate detoxification system, upregulating ROS during inflammation, and utilizing ROS as messenger molecules. In this Perspective, recent studies are discussed that demonstrate ROS as signaling molecules for gene regulation by combining two emergent properties of the guanine (G) heterocycle in DNA, namely, oxidation sensitivity and a propensity for G-quadruplex (G4) folding, both of which depend upon sequence context. In human gene promoters, this results from an elevated 5'-GG-3' dinucleotide frequency and GC enrichment near transcription start sites. Oxidation of DNA by ROS drives conversion of G to 8-oxo-7,8-dihydroguanine (OG) to mark target promoters for base excision repair initiated by OG-glycosylase I (OGG1). Sequence-dependent mechanisms for gene activation are available to OGG1 to induce transcription. Either OGG1 releases OG to yield an abasic site driving formation of a non-canonical fold, such as a G4, to be displayed to apurinic/apyrimidinic 1 (APE1) and stalling on the fold to recruit activating factors, or OGG1 binds OG and facilitates activator protein recruitment. The mechanisms described drive induction of stress response, DNA repair, or estrogen-induced genes, and these pathways are novel potential anticancer targets for therapeutic intervention. Chemical concepts provide a framework to discuss the regulatory or possible epigenetic potential of the OG modification in DNA, in which DNA "damage" and non-canonical folds collaborate to turn on or off gene expression. The next steps for scientific discovery in this growing field are discussed.
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Affiliation(s)
- Aaron M. Fleming
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
| | - Cynthia J. Burrows
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
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21
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Poetsch AR. The genomics of oxidative DNA damage, repair, and resulting mutagenesis. Comput Struct Biotechnol J 2020; 18:207-219. [PMID: 31993111 PMCID: PMC6974700 DOI: 10.1016/j.csbj.2019.12.013] [Citation(s) in RCA: 170] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/13/2019] [Accepted: 12/21/2019] [Indexed: 12/22/2022] Open
Abstract
Reactive oxygen species are a constant threat to DNA as they modify bases with the risk of disrupting genome function, inducing genome instability and mutation. Such risks are due to primary oxidative DNA damage and also mediated by the repair process. This leads to a delicate decision process for the cell as to whether to repair a damaged base at a specific genomic location or better leave it unrepaired. Persistent DNA damage can disrupt genome function, but on the other hand it can also contribute to gene regulation by serving as an epigenetic mark. When such processes are out of balance, pathophysiological conditions could get accelerated, because oxidative DNA damage and resulting mutagenic processes are tightly linked to ageing, inflammation, and the development of multiple age-related diseases, such as cancer and neurodegenerative disorders. Recent technological advancements and novel data analysis strategies have revealed that oxidative DNA damage, its repair, and related mutations distribute heterogeneously over the genome at multiple levels of resolution. The involved mechanisms act in the context of genome sequence, in interaction with genome function and chromatin. This review addresses what we currently know about the genome distribution of oxidative DNA damage, repair intermediates, and mutations. It will specifically focus on the various methodologies to measure oxidative DNA damage distribution and discuss the mechanistic conclusions derived from the different approaches. It will also address the consequences of oxidative DNA damage, specifically how it gives rise to mutations, genome instability, and how it can act as an epigenetic mark.
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22
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Kitsera N, Rodriguez-Alvarez M, Emmert S, Carell T, Khobta A. Nucleotide excision repair of abasic DNA lesions. Nucleic Acids Res 2019; 47:8537-8547. [PMID: 31226203 PMCID: PMC6895268 DOI: 10.1093/nar/gkz558] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/28/2019] [Accepted: 06/18/2019] [Indexed: 01/05/2023] Open
Abstract
Apurinic/apyrimidinic (AP) sites are a class of highly mutagenic and toxic DNA lesions arising in the genome from a number of exogenous and endogenous sources. Repair of AP lesions takes place predominantly by the base excision pathway (BER). However, among chemically heterogeneous AP lesions formed in DNA, some are resistant to the endonuclease APE1 and thus refractory to BER. Here, we employed two types of reporter constructs accommodating synthetic APE1-resistant AP lesions to investigate the auxiliary repair mechanisms in human cells. By combined analyses of recovery of the transcription rate and suppression of transcriptional mutagenesis at specifically positioned AP lesions, we demonstrate that nucleotide excision repair pathway (NER) efficiently removes BER-resistant AP lesions and significantly enhances the repair of APE1-sensitive ones. Our results further indicate that core NER components XPA and XPF are equally required and that both global genome (GG-NER) and transcription coupled (TC-NER) subpathways contribute to the repair.
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Affiliation(s)
- Nataliya Kitsera
- Unit "Responses to DNA Lesions", Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55131, Germany
| | - Marta Rodriguez-Alvarez
- Unit "Responses to DNA Lesions", Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55131, Germany
| | - Steffen Emmert
- Clinic and Policlinic for Dermatology and Venereology, University Medical Center Rostock, Rostock 18057, Germany
| | - Thomas Carell
- Center for Integrated Protein Science at the Department of Chemistry, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Andriy Khobta
- Unit "Responses to DNA Lesions", Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55131, Germany
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23
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Fleming AM, Zhu J, Ding Y, Burrows CJ. Location dependence of the transcriptional response of a potential G-quadruplex in gene promoters under oxidative stress. Nucleic Acids Res 2019; 47:5049-5060. [PMID: 30916339 PMCID: PMC6547423 DOI: 10.1093/nar/gkz207] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 02/09/2019] [Accepted: 03/18/2019] [Indexed: 12/25/2022] Open
Abstract
Oxidation of the guanine (G) heterocycle to 8-oxo-7,8-dihydroguanine (OG) in mammalian gene promoters was demonstrated to induce transcription. Potential G-quadruplex forming sequences (PQSs) in promoters have a high density of G nucleotides rendering them highly susceptible to oxidation and possible gene activation. The VEGF PQS with OG or an abasic site were synthesized at key locations in the SV40 or HSV-TK model promoters to determine the location dependency in the gene expression profile in human cells. The PQS location with respect to the transcription start site (TSS) and strand of occupancy (coding versus non-coding strand) are key parameters that determine the magnitude and direction in which gene expression changes with the chemically modified VEGF PQS. The greatest impact observed for OG or F in the PQS context in these promoters was within ∼200 bp of the TSS. Established PQSs found to occur naturally in a similar location relative to the TSS for possible oxidation-induced gene activation include c-MYC, KRAS, c-KIT, HIF-1α, PDGF-A and hTERT. The studies provide experimental constraints that were used to probe bioinformatic data regarding PQSs in the human genome for those that have the possibility to be redox switches for gene regulation.
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Affiliation(s)
- Aaron M Fleming
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
| | - Judy Zhu
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
| | - Yun Ding
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
| | - Cynthia J Burrows
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
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8-OxoG in GC-rich Sp1 binding sites enhances gene transcription in adipose tissue of juvenile mice. Sci Rep 2019; 9:15618. [PMID: 31666587 PMCID: PMC6821754 DOI: 10.1038/s41598-019-52139-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 10/12/2019] [Indexed: 12/27/2022] Open
Abstract
The oxidation of guanine to 8-oxoguanine (8-oxoG) is the most common type of oxidative DNA lesion. There is a growing body of evidence indicating that 8-oxoG is not only pre-mutagenic, but also plays an essential role in modulating gene expression along with its cognate repair proteins. In this study, we investigated the relationship between 8-oxoG formed under intrinsic oxidative stress conditions and gene expression in adipose and lung tissues of juvenile mice. We observed that transcriptional activity and the number of active genes were significantly correlated with the distribution of 8-oxoG in gene promoter regions, as determined by reverse-phase liquid chromatography/mass spectrometry (RP-LC/MS), and 8-oxoG and RNA sequencing. Gene regulation by 8-oxoG was not associated with the degree of 8-oxoG formation. Instead, genes with GC-rich transcription factor binding sites in their promoters became more active with increasing 8-oxoG abundance as also demonstrated by specificity protein 1 (Sp1)- and estrogen response element (ERE)-luciferase assays in human embryonic kidney (HEK293T) cells. These results indicate that the occurrence of 8-oxoG in GC-rich Sp1 binding sites is important for gene regulation during adipose tissue development.
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25
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Pan L, Wang H, Luo J, Zeng J, Pi J, Liu H, Liu C, Ba X, Qu X, Xiang Y, Boldogh I, Qin X. Epigenetic regulation of TIMP1 expression by 8-oxoguanine DNA glycosylase-1 binding to DNA:RNA hybrid. FASEB J 2019; 33:14159-14170. [PMID: 31652414 DOI: 10.1096/fj.201900993rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
8-Oxoguanine DNA glycosylase-1 (OGG1)-initiated base excision repair pathway is primarily responsible for 7, 8-dihydro-8-oxoguanine (8-oxoG) removal from DNA. Recent studies, however, have shown that 8-oxoG in gene regulatory elements may serve as an epigenetic mark, and OGG1 has distinct functions in modulating gene expression. Genome-wide mapping of oxidative stress-induced OGG1 enrichment within introns was documented, but its significance has not yet been fully characterized. Here, we explored whether OGG1 recruited to intron 1 of tissue inhibitor of metalloproteinase-1 (TIMP1) gene and modulated its expression. Using chromatin and DNA:RNA hybrid immunoprecipitation assays, we report recruitment of OGG1 to the DNA:RNA hybrid in intron 1, where it increases nascent RNA but lowers mRNA levels in O3-exposed human airway epithelial cells and mouse lungs. Decrease in TIMP1 expression is alleviated by antioxidant administration, small interfering RNA depletion, or inhibition of OGG1 binding to its genomic substrate. In vitro studies revealed direct interaction between OGG1 and 8-oxoG containing DNA:RNA hybrid, without excision of its substrate. Inhibition of OGG1 binding to DNA:RNA hybrid translated into an increase in TIMP1 expression and a decrease in oxidant-induced lung inflammatory responses as well as airway remodeling. Data documented here reveal a novel molecular link between OGG1 at damaged sites and transcription dynamics that may contribute to oxidative stress-induced cellular and tissue responses.-Pan, L., Wang, H., Luo, J., Zeng, J., Pi, J., Liu, H., Liu, C., Ba, X., Qu, X., Xiang, Y., Boldogh, I., Qin, X. Epigenetic regulation of TIMP1 expression by 8-oxoguanine DNA glycosylase-1 binding to DNA:RNA hybrid.
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Affiliation(s)
- Lang Pan
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Hui Wang
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Jinhua Luo
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Ji Zeng
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Jiao Pi
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Huijun Liu
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Chi Liu
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Xueqing Ba
- The Key Laboratory of Molecular Epigenetics, Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, Changchun, China
| | - Xiangping Qu
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Yang Xiang
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
| | - Istvan Boldogh
- Department of Microbiology and Immunology, School of Medicine, The University of Texas Medical Branch at Galveston, Galveston, Texas, USA
| | - Xiaoqun Qin
- Department of Physiology, School of Basic Medicine, Xiangya Medical School, Central South University, Changsha, China
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Abstract
Cellular damage produced by conditions generating oxidative stress have far-reaching implications in human disease that encompass, but are not restricted to aging, cardiovascular disease, type 2 diabetes, airway inflammation/asthma, cancer, and metabolic syndrome including visceral obesity, insulin resistance, fatty liver disease, and dyslipidemia. Although there are numerous sources and cellular targets of oxidative stress, this review will highlight literature that has investigated downstream consequences of oxidatively-induced DNA damage in both nuclear and mitochondrial genomes. The presence of such damage can in turn, directly and indirectly modulate cellular transcriptional and repair responses to such stressors. As such, the persistence of base damage can serve as a key regulator in coordinated gene-response cascades. Conversely, repair of these DNA lesions serves as both a suppressor of mutagenesis and by inference carcinogenesis, and as a signal for the cessation of ongoing oxidative stress. A key enzyme in all these processes is 8-oxoguanine DNA glycosylase (OGG1), which, via non-catalytic binding to oxidatively-induced DNA damage in promoter regions, serves as a nucleation site around which changes in large-scale regulation of inflammation-associated gene expression can occur. Further, the catalytic function of OGG1 can alter the three-dimensional structure of specialized DNA sequences, leading to changes in transcriptional profiles. This review will concentrate on adverse deleterious health effects that are associated with both the diminution of OGG1 activity via population-specific polymorphic variants and the complete loss of OGG1 in murine models. This mouse model displays diet- and age-related induction of metabolic syndrome, highlighting a key role for OGG1 in protecting against these phenotypes. Conversely, recent investigations using murine models having enhanced global expression of a mitochondrial-targeted OGG1 demonstrate that they are highly resistant to diet-induced disease. These data suggest strategies through which therapeutic interventions could be designed for reducing or limiting adverse human health consequences to these ubiquitous stressors.
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Affiliation(s)
- Harini Sampath
- Department of Nutritional Sciences and New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, 08901, United States.
| | - R Stephen Lloyd
- Oregon Institute for Occupational Health Sciences, Department of Molecular and Medical Genetics, Oregon Health & Sciences University, Portland, Oregon, 97239, United States.
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27
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Cogoi S, Ferino A, Miglietta G, Pedersen EB, Xodo LE. The regulatory G4 motif of the Kirsten ras (KRAS) gene is sensitive to guanine oxidation: implications on transcription. Nucleic Acids Res 2019; 46:661-676. [PMID: 29165690 PMCID: PMC5778462 DOI: 10.1093/nar/gkx1142] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/31/2017] [Indexed: 01/10/2023] Open
Abstract
KRAS is one of the most mutated genes in human cancer. It is controlled by a G4 motif located upstream of the transcription start site. In this paper, we demonstrate that 8-oxoguanine (8-oxoG), being more abundant in G4 than in non-G4 regions, is a new player in the regulation of this oncogene. We designed oligonucleotides mimicking the KRAS G4-motif and found that 8-oxoG impacts folding and stability of the G-quadruplex. Dimethylsulphate-footprinting showed that the G-run carrying 8-oxoG is excluded from the G-tetrads and replaced by a redundant G-run in the KRAS G4-motif. Chromatin immunoprecipitation revealed that the base-excision repair protein OGG1 is recruited to the KRAS promoter when the level of 8-oxoG in the G4 region is raised by H2O2. Polyacrylamide gel electrophoresis evidenced that OGG1 removes 8-oxoG from the G4-motif in duplex, but when folded it binds to the G-quadruplex in a non-productive way. We also found that 8-oxoG enhances the recruitment to the KRAS promoter of MAZ and hnRNP A1, two nuclear factors essential for transcription. All this suggests that 8-oxoG in the promoter G4 region could have an epigenetic potential for the control of gene expression.
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Affiliation(s)
- Susanna Cogoi
- Department of Medicine, University of Udine, 33100 Udine, Italy
| | - Annalisa Ferino
- Department of Medicine, University of Udine, 33100 Udine, Italy
| | | | - Erik B Pedersen
- Nucleic Acid Center, Institute of Physics and Chemistry, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Luigi E Xodo
- Department of Medicine, University of Udine, 33100 Udine, Italy
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Fleming AM, Zhu J, Howpay Manage SA, Burrows CJ. Human NEIL3 Gene Expression Regulated by Epigenetic-Like Oxidative DNA Modification. J Am Chem Soc 2019; 141:11036-11049. [PMID: 31241930 PMCID: PMC6640110 DOI: 10.1021/jacs.9b01847] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
The NEIL3 DNA repair gene is induced in cells
or animal models experiencing oxidative or inflammatory stress along
with oxidation of guanine (G) to 8-oxo-7,8-dihydroguanine (OG) in
the genome. We hypothesize that a G-rich promoter element that is
a potential G-quadruplex-forming sequence (PQS) in NEIL3 is a site for introduction of OG with epigenetic-like potential
for gene regulation. Activation occurs when OG is formed in the NEIL3 PQS located near the transcription start site. Oxidative
stress either introduced by TNFα or synthetically incorporated
into precise locations focuses the base excision repair process to
read and catalyze removal of OG via OG-glycosylase I (OGG1), yielding
an abasic site (AP). Thermodynamic studies showed that AP destabilizes
the duplex, enabling a structural transition of the sequence to a
G-quadruplex (G4) fold that positions the AP in a loop facilitated
by the NEIL3 PQS having five G runs in which the
four unmodified runs adopt a stable G4. This presents AP to apurinic/apyrimidinic
endonuclease 1 (APE1) that poorly cleaves the AP backbone in this
context according to in vitro studies, allowing the protein to function
as a trans activator of transcription. The proposal is supported by
chemical studies in cellulo and in vitro. Activation of NEIL3 expression via the proposed mechanism allows cells to respond to
mutagenic DNA damage removed by NEIL3 associated with oxidative or
inflammatory stress. Lastly, inspection of many mammalian genomes
identified conservation of the NEIL3 PQS, suggesting
this sequence was favorably selected to function as a redox switch
with OG as the epigenetic-like regulatory modification.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Judy Zhu
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Shereen A Howpay Manage
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Cynthia J Burrows
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
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29
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Fleming AM, Zhu J, Ding Y, Esders S, Burrows CJ. Oxidative Modification of Guanine in a Potential Z-DNA-Forming Sequence of a Gene Promoter Impacts Gene Expression. Chem Res Toxicol 2019; 32:899-909. [PMID: 30821442 DOI: 10.1021/acs.chemrestox.9b00041] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One response to oxidation of guanine (G) to 8-oxo-7,8-dihydroguanine (OG) in a gene promoter is regulation of mRNA expression suggesting an epigenetic-like role for OG. A proposed mechanism involves G oxidation within a potential G-quadruplex-forming sequence (PQS) in the promoter, enabling a structural shift from B-DNA to a G-quadruplex fold (G4). When OG was located in the coding vs template strand, base excision repair led to an on/off transcriptional switch. Herein, a G-rich, potential Z-DNA-forming sequence (PZS) comprised of a d(GC) n repeat was explored to determine whether oxidation in this motif was also a transcriptional switch. Bioinformatic analysis found 1650 PZSs of length >10 nts in the human genome that were overrepresented in promoters and 5'-UTRs. Studies in human cells transfected with a luciferase reporter plasmid in which OG was synthesized in a PZS context in the promoter found that a coding strand OG increased expression and a template strand OG decreased expression. The initial base excision repair product of OG, an abasic site (AP), was also found to yield similar expression changes as OG. Biophysical studies on model Z-DNA strands found OG favored a shift in the equilibrium to Z-DNA from B-DNA, while an AP disrupted Z-DNA to favor a hairpin, placing AP in the loop where it is a poor substrate for the endonuclease APE1. Overall, the impact of OG and AP in a PZS on gene expression was similar to that in a PQS but reduced in magnitude.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry , University of Utah , 315S 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Judy Zhu
- Department of Chemistry , University of Utah , 315S 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Yun Ding
- Department of Chemistry , University of Utah , 315S 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Selma Esders
- Department of Chemistry , University of Utah , 315S 1400 East , Salt Lake City , Utah 84112-0850 , United States
| | - Cynthia J Burrows
- Department of Chemistry , University of Utah , 315S 1400 East , Salt Lake City , Utah 84112-0850 , United States
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30
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Bokhari B, Sharma S. Stress Marks on the Genome: Use or Lose? Int J Mol Sci 2019; 20:ijms20020364. [PMID: 30654540 PMCID: PMC6358951 DOI: 10.3390/ijms20020364] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/31/2018] [Accepted: 01/10/2019] [Indexed: 02/06/2023] Open
Abstract
Oxidative stress and the resulting damage to DNA are inevitable consequence of endogenous physiological processes further amplified by cellular responses to environmental exposures. If left unrepaired, oxidative DNA lesions can block essential processes such as transcription and replication or can induce mutations. Emerging data also indicate that oxidative base modifications such as 8-oxoG in gene promoters may serve as epigenetic marks, and/or provide a platform for coordination of the initial steps of DNA repair and the assembly of the transcriptional machinery to launch adequate gene expression alterations. Here, we briefly review the current understanding of oxidative lesions in genome stability maintenance and regulation of basal and inducible transcription.
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Affiliation(s)
- Bayan Bokhari
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, 520 W Street, NW, Washington, DC 20059, USA.
- Department of Biochemistry, Faculty of Applied Medical Science, Umm Al- Qura University, Makkah 21421, Saudi Arabia.
| | - Sudha Sharma
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, 520 W Street, NW, Washington, DC 20059, USA.
- National Human Genome Center, College of Medicine, Howard University, 2041 Georgia Avenue, NW, Washington, DC 20060, USA.
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31
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Redstone SCJ, Fleming AM, Burrows CJ. Oxidative Modification of the Potential G-Quadruplex Sequence in the PCNA Gene Promoter Can Turn on Transcription. Chem Res Toxicol 2019; 32:437-446. [PMID: 30604962 DOI: 10.1021/acs.chemrestox.8b00332] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Because of its low redox potential, guanine (G) is the most frequent site of oxidation in the genome. Metabolic processes generate reactive oxygen species (ROS) that can oxidize G to yield 8-oxo-7,8-dihydroguanine (OG) as a key two-electron oxidation product. In a genome, G-rich sites including many gene promoters are sensitive to oxidative modification, and some of these regions have the propensity to form G-quadruplexes (G4s). Recently, OG formation in G-rich gene promoters was demonstrated to regulate mRNA expression via the base excision repair (BER) pathway. The proliferating cell nuclear antigen ( PCNA) gene was previously found to be activated by metabolic ROS, and the gene has a five G-track potential G4 in the coding strand of its promoter. Herein, we demonstrated the ability for four G runs of the PCNA promoter sequence to adopt a parallel-stranded G4. Next, we identified G nucleotides in the PCNA G4 sequence sensitive to oxidative modification. The G oxidation product OG and its initial BER product, an abasic site, were synthetically incorporated into the four- and five-track PCNA sequences at the sensitive sites followed by interrogation of G4 folding by five methods. We found the modifications impacted the G4 folds with positional dependency. Additionally, the fifth G track maintained the stability of the modified G4s by extrusion of the oxidatively modified G run. Finally, we synthetically inserted a portion of the promoter into a reporter plasmid with OG at select oxidation-prone positions to monitor expression in human glioblastoma cells. Our results demonstrate that OG formation in the context of the PCNA G4 can lead to increased gene expression consistent with the previous studies identifying that metabolic ROS activates transcription of the gene. This study provides another example of a G4 with the potential to serve as a regulatory agent for gene expression upon G oxidation.
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Affiliation(s)
- Samuel C J Redstone
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Aaron M Fleming
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Cynthia J Burrows
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
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32
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Poetsch AR, Boulton SJ, Luscombe NM. Genomic landscape of oxidative DNA damage and repair reveals regioselective protection from mutagenesis. Genome Biol 2018; 19:215. [PMID: 30526646 PMCID: PMC6284305 DOI: 10.1186/s13059-018-1582-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 11/08/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND DNA is subject to constant chemical modification and damage, which eventually results in variable mutation rates throughout the genome. Although detailed molecular mechanisms of DNA damage and repair are well understood, damage impact and execution of repair across a genome remain poorly defined. RESULTS To bridge the gap between our understanding of DNA repair and mutation distributions, we developed a novel method, AP-seq, capable of mapping apurinic sites and 8-oxo-7,8-dihydroguanine bases at approximately 250-bp resolution on a genome-wide scale. We directly demonstrate that the accumulation rate of apurinic sites varies widely across the genome, with hot spots acquiring many times more damage than cold spots. Unlike single nucleotide variants (SNVs) in cancers, damage burden correlates with marks for open chromatin notably H3K9ac and H3K4me2. Apurinic sites and oxidative damage are also highly enriched in transposable elements and other repetitive sequences. In contrast, we observe a reduction at chromatin loop anchors with increased damage load towards inactive compartments. Less damage is found at promoters, exons, and termination sites, but not introns, in a seemingly transcription-independent but GC content-dependent manner. Leveraging cancer genomic data, we also find locally reduced SNV rates in promoters, coding sequence, and other functional elements. CONCLUSIONS Our study reveals that oxidative DNA damage accumulation and repair differ strongly across the genome, but culminate in a previously unappreciated mechanism that safeguards the regulatory and coding regions of genes from mutations.
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Affiliation(s)
- Anna R Poetsch
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
- Okinawa Institute of Science and Technology Graduate University, Okinawa, 904-0495, Japan.
- UCL Genetics Institute, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Simon J Boulton
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Nicholas M Luscombe
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Okinawa Institute of Science and Technology Graduate University, Okinawa, 904-0495, Japan
- UCL Genetics Institute, University College London, Gower Street, London, WC1E 6BT, UK
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Wang R, Hao W, Pan L, Boldogh I, Ba X. The roles of base excision repair enzyme OGG1 in gene expression. Cell Mol Life Sci 2018; 75:3741-3750. [PMID: 30043138 PMCID: PMC6154017 DOI: 10.1007/s00018-018-2887-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/11/2018] [Accepted: 07/19/2018] [Indexed: 12/13/2022]
Abstract
Modifications of DNA strands and nucleobases-both induced and accidental-are associated with unfavorable consequences including loss or gain in genetic information and mutations. Therefore, DNA repair proteins have essential roles in keeping genome fidelity. Recently, mounting evidence supports that 8-oxoguanine (8-oxoG), one of the most abundant genomic base modifications generated by reactive oxygen and nitrogen species, along with its cognate repair protein 8-oxoguanine DNA glycosylase1 (OGG1), has distinct roles in gene expression through transcription modulation or signal transduction. Binding to 8-oxoG located in gene regulatory regions, OGG1 acts as a transcription modulator, which can control transcription factor homing, induce allosteric transition of G-quadruplex structure, or recruit chromatin remodelers. In addition, post-repair complex formed between OGG1 and its repair product-free 8-oxoG increases the levels of active small GTPases and induces downstream signaling cascades to trigger gene expressions. The present review discusses how cells exploit damaged guanine base(s) and the authentic repair protein to orchestrate a profile of various transcriptomes in redox-regulated biological processes.
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Affiliation(s)
- Ruoxi Wang
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, Jilin, China
- School of Life Science, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Wenjing Hao
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, Jilin, China
- School of Life Science, Northeast Normal University, Changchun, 130024, Jilin, China
| | - Lang Pan
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, Jilin, China
- Department of Physiology, Xiangya Medicine School in Central South University, Changsha, 410078, Hunan, China
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX, 77555, USA
- Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston, TX, 77555, USA
| | - Xueqing Ba
- Key Laboratory of Molecular Epigenetics of Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, Jilin, China.
- School of Life Science, Northeast Normal University, Changchun, 130024, Jilin, China.
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34
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Omaga CA, Fleming AM, Burrows CJ. The Fifth Domain in the G-Quadruplex-Forming Sequence of the Human NEIL3 Promoter Locks DNA Folding in Response to Oxidative Damage. Biochemistry 2018; 57:2958-2970. [PMID: 29718661 DOI: 10.1021/acs.biochem.8b00226] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA oxidation is an inevitable and usually detrimental process, but the cell is capable of reversing this state because the cell possesses a highly developed set of DNA repair machineries, including the DNA glycosylase NEIL3 that is encoded by the NEIL3 gene. In this work, the G-rich promoter region of the human NEIL3 gene was shown to fold into a dynamic G-quadruplex (G4) structure under nearly physiological conditions using spectroscopic techniques (e.g., nuclear magnetic resonance, circular dichroism, fluorescence, and ultraviolet-visible) and DNA polymerase stop assays. The presence of 8-oxo-7,8-dihydroguanine (OG) modified the properties of the NEIL3 G4 and entailed the recruitment of the fifth domain to function as a "spare tire", in which an undamaged fifth G-track is swapped for the damaged section of the G4. The polymerase stop assay findings also revealed that owing to its dynamic polymorphism, the NEIL3 G4 is more readily bypassed by DNA polymerase I (Klenow fragment) than well-known oncogene G4s are. This study identifies the NEIL3 promoter possessing a G-rich element that can adopt a G4 fold, and when OG is incorporated, the sequence can lock into a more stable G4 fold via recruitment of the fifth track of Gs.
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Affiliation(s)
- Carla A Omaga
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Aaron M Fleming
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
| | - Cynthia J Burrows
- Department of Chemistry , University of Utah , Salt Lake City , Utah 84112-0850 , United States
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35
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Takahashi S, Kim KT, Podbevšek P, Plavec J, Kim BH, Sugimoto N. Recovery of the Formation and Function of Oxidized G-Quadruplexes by a Pyrene-Modified Guanine Tract. J Am Chem Soc 2018; 140:5774-5783. [PMID: 29608858 DOI: 10.1021/jacs.8b01577] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxidation is one of the frequent causes of DNA damage, especially to guanine bases. Guanine bases in the G-quadruplex (G4) are sensitive to damage by oxidation, resulting in transformation to 8-oxo-7,8-dihydroguanine (8-oxoG). Because the formation of G4 represses the expression of some cancer-related genes, the presence of 8-oxoG in a G4 sequence might affect G4 formation and induce cancer progression. Thus, oxidized-G4 formation must be controlled using a chemical approach. In the present study, we investigated the effect of introduction of 8-oxoG into a G4 sequence on the formation and function of the G4 structure. The 8-oxoG-containing G4 derived from the promoter region of the human vascular endothelial growth factor ( VEGF) gene differed topologically from unoxidized G4. The oxidized VEGF G4 did not act as a replication block and was not stabilized by the G4-binding protein nucleolin. To recover G4 function, we developed an oligonucleotide consisting of a pyrene-modified guanine tract that replaces the oxidized guanine tract and forms stable intermolecular G4s with the other intact guanine tracts. When this oligonucleotide was used, the oxidized G4 stalled replication and was stabilized by nucleolin as with the unmodified G4. This strategy generally enables recovery of the function of any oxidized G4s and therefore has potential for cancer therapy.
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Affiliation(s)
| | - Ki Tae Kim
- Department of Chemistry, Division of Advanced Materials Science , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
| | - Peter Podbevšek
- Slovenian NMR Center , National Institute of Chemistry , SI-1000 Ljubljana , Slovenia
| | - Janez Plavec
- Slovenian NMR Center , National Institute of Chemistry , SI-1000 Ljubljana , Slovenia
| | - Byeang Hyean Kim
- Department of Chemistry, Division of Advanced Materials Science , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Republic of Korea
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Kitsera N, Allgayer J, Parsa E, Geier N, Rossa M, Carell T, Khobta A. Functional impacts of 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxycytosine at a single hemi-modified CpG dinucleotide in a gene promoter. Nucleic Acids Res 2017; 45:11033-11042. [PMID: 28977475 PMCID: PMC5737506 DOI: 10.1093/nar/gkx718] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 08/08/2017] [Indexed: 12/19/2022] Open
Abstract
Enzymatic oxidation of 5-methylcytosine (5-mC) in the CpG dinucleotides to 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-fC) and 5-carboxycytosine (5-caC) has central role in the process of active DNA demethylation and epigenetic reprogramming in mammals. However, it is not known whether the 5-mC oxidation products have autonomous epigenetic or regulatory functions in the genome. We used an artificial upstream promoter constituted of one cAMP response element (CRE) to measure the impact of 5-mC in a hemi-methylated CpG on the promoter activity and further explored the consequences of 5-hmC, 5-fC, and 5-caC in the same system. All modifications induced mild impairment of the CREB transcription factor binding to the consensus 5'-TGACGTCA-3' CRE sequence. The decrease of the gene expression by 5-mC or 5-hmC was proportional to the impairment of CREB binding and had a steady character over at least 48 h. In contrast, promoters containing single 5-fC or 5-caC underwent further progressive loss of activity, up to an almost complete repression. This decline was dependent on the thymine-DNA glycosylase (TDG). The results thus indicate that 5-fC and 5-caC can provide a signal for perpetuation and enhancement of the repressed transcriptional state by a mechanism that requires base excision repair.
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Affiliation(s)
- Nataliya Kitsera
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55131, Germany
| | - Julia Allgayer
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University of Mainz, Mainz 55128, Germany
| | - Edris Parsa
- Center for Integrated Protein Science at the Department of Chemistry, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Nadine Geier
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55131, Germany
| | - Martin Rossa
- Center for Integrated Protein Science at the Department of Chemistry, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Thomas Carell
- Center for Integrated Protein Science at the Department of Chemistry, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Andriy Khobta
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz 55131, Germany.,Institute of Pharmacy and Biochemistry, Johannes Gutenberg University of Mainz, Mainz 55128, Germany
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Ba X, Boldogh I. 8-Oxoguanine DNA glycosylase 1: Beyond repair of the oxidatively modified base lesions. Redox Biol 2017; 14:669-678. [PMID: 29175754 PMCID: PMC5975208 DOI: 10.1016/j.redox.2017.11.008] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/08/2017] [Accepted: 11/08/2017] [Indexed: 12/11/2022] Open
Abstract
Oxidative stress and the resulting damage to genomic DNA are inevitable consequences of endogenous physiological processes, and they are amplified by cellular responses to environmental exposures. One of the most frequent reactions of reactive oxygen species with DNA is the oxidation of guanine to pre-mutagenic 8-oxo-7,8-dihydroguanine (8-oxoG). Despite the vulnerability of guanine to oxidation, vertebrate genes are primarily embedded in GC-rich genomic regions, and over 72% of the promoters of human genes belong to a class with a high GC content. In the promoter, 8-oxoG may serve as an epigenetic mark, and when complexed with the oxidatively inactivated repair enzyme 8-oxoguanine DNA glycosylase 1, provide a platform for the coordination of the initial steps of DNA repair and the assembly of the transcriptional machinery to launch the prompt and preferential expression of redox-regulated genes. Deviations/variations from this artful coordination may be the etiological links between guanine oxidation and various cellular pathologies and diseases during ageing processes.
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Affiliation(s)
- Xueqing Ba
- The Key Laboratory of Molecular Epigenetics of Ministry of Education, Northeast Normal University, Changchun, Jilin 130024, China; School of Life Science, Northeast Normal University, Changchun, Jilin 130024, China.
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA; Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA.
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Fleming AM, Zhu J, Ding Y, Burrows CJ. 8-Oxo-7,8-dihydroguanine in the Context of a Gene Promoter G-Quadruplex Is an On-Off Switch for Transcription. ACS Chem Biol 2017; 12:2417-2426. [PMID: 28829124 PMCID: PMC5604463 DOI: 10.1021/acschembio.7b00636] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
Interplay
between DNA repair of the oxidatively modified base 8-oxo-7,8-dihydroguanine
(OG) and transcriptional activation has been documented in mammalian
genes. Previously, we synthesized OG into the VEGF potential G-quadruplex sequence (PQS) in the coding strand of a
luciferase promoter to identify that base excision repair (BER) unmasked
the G-quadruplex (G4) fold for gene activation. In the present work,
OG was site-specifically synthesized into a luciferase reporter plasmid
to follow the time-dependent expression in mammalian cells when OG
in the VEGF PQS context was located in the coding
vs template strands of the luciferase promoter. Removal of OG from
the coding strand by OG glycosylase-1 (OGG1)-mediated BER upregulated
transcription. When OG was in the template strand in the VEGF PQS context, transcription was downregulated by a BER-independent
process. The time course changes in transcription show that repair
in the template strand was more efficient than repair in the coding
strand. Promoters were synthesized with an OG:A base pair that requires
repair on both strands to yield a canonical G:C base pair. By monitoring
the up/down luciferase expression, we followed the timing of repair
of an OG:A base pair occurring on both strands in mammalian cells
in which one lesion resides in a G-quadruplex loop and one in a potential
i-motif. Depending on the strand in which OG resides, coding vs template,
this modification is an up/downregulator of transcription that couples
DNA repair with transcriptional regulation.
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Affiliation(s)
- Aaron M. Fleming
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, United States
| | - Judy Zhu
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, United States
| | - Yun Ding
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, United States
| | - Cynthia J. Burrows
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, United States
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Fleming AM, Burrows CJ. 8-Oxo-7,8-dihydroguanine, friend and foe: Epigenetic-like regulator versus initiator of mutagenesis. DNA Repair (Amst) 2017. [PMID: 28629775 DOI: 10.1016/j.dnarep.2017.06.009] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A high flux of reactive oxygen species during oxidative stress results in oxidative modification of cellular components including DNA. Oxidative DNA "damage" to the heterocyclic bases is considered deleterious because polymerases may incorrectly read the modifications causing mutations. A prominent member in this class is the oxidized guanine base 8-oxo-7,8-dihydroguanine (OG) that is moderately mutagenic effecting G→T transversion mutations. Recent reports have identified that formation of OG in G-rich regulatory elements in the promoters of the VEGF, TNFα, and SIRT1 genes can increase transcription via activation of the base excision repair (BER) pathway. Work in our laboratory with the G-rich sequence in the promoter of VEGF concluded that BER drives a shift in structure to a G-quadruplex conformation leading to gene activation in mammalian cells. More specifically, removal of OG from the duplex context by 8-oxoguanine glycosylase 1 (OGG1) produces an abasic site (AP) that destabilizes the duplex, shifting the equilibrium toward the G-quadruplex fold because of preferential extrusion of the AP into a loop. The AP is bound but inefficiently cleaved by apurinic/apyrimidinic endoDNase I (APE1) that likely allows recruitment of activating transcription factors for gene induction. The ability of OG to induce transcription ascribes a regulatory or epigenetic-like role for this oxidatively modified base. We compare OG to the 5-methylcytosine (5mC) epigenetic pathway including its oxidized derivatives, some of which poise genes for transcription while also being substrates for BER. The mutagenic potential of OG to induce only ∼one-third the number of mutations (G→T) compared to deamination of 5mC producing C→T mutations is described. These comparisons blur the line between friendly epigenetic base modifications and those that are foes, i.e. DNA "damage," causing genetic mutations.
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Affiliation(s)
- Aaron M Fleming
- Department of Chemistry, University of Utah, 315 S 1400 East, Salt Lake City, UT 84112-0850, USA.
| | - Cynthia J Burrows
- Department of Chemistry, University of Utah, 315 S 1400 East, Salt Lake City, UT 84112-0850, USA.
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Kolbanovskiy M, Chowdhury MA, Nadkarni A, Broyde S, Geacintov NE, Scicchitano DA, Shafirovich V. The Nonbulky DNA Lesions Spiroiminodihydantoin and 5-Guanidinohydantoin Significantly Block Human RNA Polymerase II Elongation in Vitro. Biochemistry 2017; 56:3008-3018. [PMID: 28514164 DOI: 10.1021/acs.biochem.7b00295] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The most common, oxidatively generated lesion in cellular DNA is 8-oxo-7,8-dihydroguanine, which can be oxidized further to yield highly mutagenic spiroiminodihydantoin (Sp) and 5-guanidinohydantoin (Gh) in DNA. In human cell-free extracts, both lesions can be excised by base excision repair and global genomic nucleotide excision repair. However, it is not known if these lesions can be removed by transcription-coupled DNA repair (TCR), a pathway that clears lesions from DNA that impede RNA synthesis. To determine if Sp or Gh impedes transcription, which could make each a viable substrate for TCR, either an Sp or a Gh lesion was positioned on the transcribed strand of DNA under the control of a promoter that supports transcription by human RNA polymerase II. These constructs were incubated in HeLa nuclear extracts that contained active RNA polymerase II, and the resulting transcripts were resolved by denaturing polyacrylamide gel electrophoresis. The structurally rigid Sp strongly blocks transcription elongation, permitting 1.6 ± 0.5% nominal lesion bypass. In contrast, the conformationally flexible Gh poses less of a block to human RNAPII, allowing 9 ± 2% bypass. Furthermore, fractional lesion bypass for Sp and Gh is minimally affected by glycosylase activity found in the HeLa nuclear extract. These data specifically suggest that both Sp and Gh may well be susceptible to TCR because each poses a significant block to human RNA polymerase II progression. A more general principle is also proposed: Conformational flexibility may be an important structural feature of DNA lesions that enhances their transcriptional bypass.
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Affiliation(s)
- Marina Kolbanovskiy
- Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003-5180, United States
| | - Moinuddin A Chowdhury
- Department of Biology, New York University , 100 Washington Square East, New York, New York 10003-5180, United States
| | - Aditi Nadkarni
- Department of Biology, New York University , 100 Washington Square East, New York, New York 10003-5180, United States
| | - Suse Broyde
- Department of Biology, New York University , 100 Washington Square East, New York, New York 10003-5180, United States
| | - Nicholas E Geacintov
- Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003-5180, United States
| | - David A Scicchitano
- Department of Biology, New York University , 100 Washington Square East, New York, New York 10003-5180, United States.,Division of Science, New York University Abu Dhabi , P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Vladimir Shafirovich
- Department of Chemistry, New York University , 100 Washington Square East, New York, New York 10003-5180, United States
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41
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Fleming AM, Ding Y, Burrows CJ. Sequencing DNA for the Oxidatively Modified Base 8-Oxo-7,8-Dihydroguanine. Methods Enzymol 2017. [PMID: 28645369 DOI: 10.1016/bs.mie.2017.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The DNA base guanine (G) can be oxidatively modified to 8-oxo-7,8-dihydroguanine (OG). Extraction of genomic DNA followed by nuclease digestion and mass spectrometry analysis has found OG is present at background levels of ~1 out of 106 Gs; however, this approach cannot determine the locations for the OGs in the genome. Thus, in this methods report, we outline three different methods (A, B, and C) for sequencing OG in DNA. Method A sequences OG by utilizing the base excision repair pathway to delete the OG nucleotide from the DNA that is then detected by Sanger sequencing as a deletion signature. Method B sequences OG by harnessing the base excision repair pathway to convert OG to an unnatural DNA base pair followed by Sanger sequencing to locate the unnatural base pair indicating where OG was located. Method C (i.e., OG-Seq) takes genomic DNA sheared to ~150bps followed by selectively biotinylating the OG-containing fragments for affinity purification and enrichment of the OG-modified strands. The OG-modified fragments are sequenced on a next-generation sequencing platform to locate OG on the genomic scale with a resolution of ~150bps. The methods outlined are then compared and contrasted allowing researchers to select the one that best suits their experimental goals.
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Affiliation(s)
| | - Yun Ding
- University of Utah, Salt Lake City, UT, United States
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42
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Oxidative DNA damage is epigenetic by regulating gene transcription via base excision repair. Proc Natl Acad Sci U S A 2017; 114:2604-2609. [PMID: 28143930 DOI: 10.1073/pnas.1619809114] [Citation(s) in RCA: 237] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Reactive oxygen species (ROS) have emerged as important cellular-signaling agents for cellular survival. Herein, we demonstrate that ROS-mediated oxidation of DNA to yield 8-oxo-7,8-dihydroguanine (OG) in gene promoters is a signaling agent for gene activation. Enhanced gene expression occurs when OG is formed in guanine-rich, potential G-quadruplex-forming sequences (PQS) in promoter-coding strands, initiating base excision repair (BER) by 8-oxoguanine DNA glycosylase (OGG1), yielding an abasic site (AP). The AP enables melting of the duplex to unmask the PQS, adopting a G-quadruplex fold in which apurinic/apyrimidinic endonuclease 1 (APE1) binds, but inefficiently cleaves, the AP for activation of vascular endothelial growth factor (VEGF) or endonuclease III-like protein 1 (NTHL1) genes. These details were mapped via synthesis of OG and AP analogs at single-nucleotide precision within the promoter of a luciferase reporter system. The reporters were analyzed in human and mouse cells while selectively knocking out or down critical BER proteins to identify the impact on luciferase expression. Identification of the oxidatively modified DNA base OG to guide BER activity in a gene promoter and impact cellular phenotype ascribes an epigenetic role to OG.
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43
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Pan L, Zhu B, Hao W, Zeng X, Vlahopoulos SA, Hazra TK, Hegde ML, Radak Z, Bacsi A, Brasier AR, Ba X, Boldogh I. Oxidized Guanine Base Lesions Function in 8-Oxoguanine DNA Glycosylase-1-mediated Epigenetic Regulation of Nuclear Factor κB-driven Gene Expression. J Biol Chem 2016; 291:25553-25566. [PMID: 27756845 DOI: 10.1074/jbc.m116.751453] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/14/2016] [Indexed: 11/06/2022] Open
Abstract
A large percentage of redox-responsive gene promoters contain evolutionarily conserved guanine-rich clusters; guanines are the bases most susceptible to oxidative modification(s). Consequently, 7,8-dihydro-8-oxoguanine (8-oxoG) is one of the most abundant base lesions in promoters and is primarily repaired via the 8-oxoguanine DNA glycosylase-1 (OOG1)-initiated base excision repair pathway. In view of a prompt cellular response to oxidative challenge, we hypothesized that the 8-oxoG lesion and the cognate repair protein OGG1 are utilized in transcriptional gene activation. Here, we document TNFα-induced enrichment of both 8-oxoG and OGG1 in promoters of pro-inflammatory genes, which precedes interaction of NF-κB with its DNA-binding motif. OGG1 bound to 8-oxoG upstream from the NF-κB motif increased its DNA occupancy by promoting an on-rate of both homodimeric and heterodimeric forms of NF-κB. OGG1 depletion decreased both NF-κB binding and gene expression, whereas Nei-like glycosylase-1 and -2 had a marginal effect. These results are the first to document a novel paradigm wherein the DNA repair protein OGG1 bound to its substrate is coupled to DNA occupancy of NF-κB and functions in epigenetic regulation of gene expression.
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Affiliation(s)
- Lang Pan
- From the Departments of Microbiology and Immunology and.,the Key Laboratory of Molecular Epigenetics, Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China, and
| | - Bing Zhu
- From the Departments of Microbiology and Immunology and
| | - Wenjing Hao
- the Key Laboratory of Molecular Epigenetics, Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China, and
| | - Xianlu Zeng
- the Key Laboratory of Molecular Epigenetics, Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China, and
| | | | - Tapas K Hazra
- Medicine, and.,the Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas 77555
| | - Muralidhar L Hegde
- the Department of Radiation Oncology and Neurology, Methodist Research Institute, Houston, Texas 77030
| | - Zsolt Radak
- From the Departments of Microbiology and Immunology and
| | - Attila Bacsi
- From the Departments of Microbiology and Immunology and
| | - Allan R Brasier
- Medicine, and.,the Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas 77555
| | - Xueqing Ba
- From the Departments of Microbiology and Immunology and .,the Key Laboratory of Molecular Epigenetics, Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China, and
| | - Istvan Boldogh
- From the Departments of Microbiology and Immunology and .,the Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas 77555
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