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Zhao ML, Stefanick DF, Nadalutti CA, Beard WA, Wilson SH, Horton JK. Temporal recruitment of base excision DNA repair factors in living cells in response to different micro-irradiation DNA damage protocols. DNA Repair (Amst) 2023; 126:103486. [PMID: 37028218 PMCID: PMC10133186 DOI: 10.1016/j.dnarep.2023.103486] [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: 11/22/2022] [Revised: 03/07/2023] [Accepted: 03/20/2023] [Indexed: 04/09/2023]
Abstract
Laser micro-irradiation across the nucleus rapidly generates localized chromatin-associated DNA lesions permitting analysis of repair protein recruitment in living cells. Recruitment of three fluorescently-tagged base excision repair factors [DNA polymerase β (pol β), XRCC1 and PARP1], known to interact with one another, was compared in gene-deleted mouse embryonic fibroblasts and in those expressing the endogenous factor. A low energy micro-irradiation (LEMI) forming direct single-strand breaks and a moderate energy (MEMI) protocol that additionally creates oxidized bases were compared. Quantitative characterization of repair factor recruitment and sensitivity to clinical PARP inhibitors (PARPi) was dependent on the micro-irradiation protocol. PARP1 recruitment was biphasic and generally occurred prior to pol β and XRCC1. After LEMI, but not after MEMI, pol β and XRCC1 recruitment was abolished by the PARPi veliparib. Consistent with this, pol β and XRCC1 recruitment following LEMI was considerably slower in PARP1-deficient cells. Surprisingly, the recruitment half-times and amplitudes for pol β were less affected by PARPi than were XRCC1 after MEMI suggesting there is a XRCC1-independent component for pol β recruitment. After LEMI, but not MEMI, pol β dissociation was more rapid than that of XRCC1. Unexpectedly, PARP1 dissociation was slowed in the absence of XRCC1 as well with a PARPi after LEMI but not MEMI, suggesting that XRCC1 facilitates PARP1 dissociation from specific DNA lesions. XRCC1-deficient cells showed pronounced hypersensitivity to the PARPi talazoparib correlating with its known cytotoxic PARP1 trapping activity. In contrast to DNA methylating agents, PARPi only minimally sensitized pol β and XRCC1-deficient cells to oxidative DNA damage suggesting differential binding of PARP1 to alternate repair intermediates. In summary, pol β, XRCC1, and PARP1 display recruitment kinetics that exhibit correlated and unique properties that depend on the DNA lesion and PARP activity revealing that there are multiple avenues utilized in the repair of chromatin-associated DNA.
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Affiliation(s)
- Ming-Lang Zhao
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Donna F Stefanick
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Cristina A Nadalutti
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - William A Beard
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Julie K Horton
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA.
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2
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Koczor CA, Thompson MK, Sharma N, Prakash A, Sobol RW. Polβ/XRCC1 heterodimerization dictates DNA damage recognition and basal Polβ protein levels without interfering with mouse viability or fertility. DNA Repair (Amst) 2023; 123:103452. [PMID: 36702010 PMCID: PMC9992099 DOI: 10.1016/j.dnarep.2023.103452] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/07/2022] [Accepted: 01/17/2023] [Indexed: 01/22/2023]
Abstract
DNA Polymerase β (Polβ) performs two critical enzymatic steps during base excision repair (BER) - gap filling (nucleotidyl transferase activity) and gap tailoring (dRP lyase activity). X-ray repair cross complementing 1 (XRCC1) facilitates the recruitment of Polβ to sites of DNA damage through an evolutionarily conserved Polβ/XRCC1 interaction interface, the V303 loop. While previous work describes the importance of the Polβ/XRCC1 interaction for human Polβ protein stability and recruitment to sites of DNA damage, the impact of disrupting the Polβ/XRCC1 interface on animal viability, physiology, and fertility is unknown. Here, we characterized the effect of disrupting Polβ/XRCC1 heterodimerization in mice and mouse cells by complimentary approaches. First, we demonstrate, via laser micro-irradiation, that mouse Polβ amino acid residues L301 and V303 are critical to facilitating Polβ recruitment to sites of DNA damage. Next, we solved the crystal structures of mouse wild type Polβ and a mutant protein harboring alterations in residues L301 and V303 (L301R/V303R). Our structural analyses suggest that Polβ amino acid residue V303 plays a role in maintaining an interaction with the oxidized form of XRCC1. Finally, we created CRISPR/Cas9-modified Polb mice with homozygous L301R/V303R mutations (PolbL301R-V303R/L301R-V303R) that are fertile yet exhibit 15% reduced body weight at 17 weeks of age, as compared to heterozygous mice. Fibroblasts derived from PolbL301R-V303R/L301R-V303R mice demonstrate that mutation of mouse Polβ's XRCC1 interaction domain leads to an ∼85% decrease in Polβ protein levels. In all, these studies are consistent with a role for the oxidized form of XRCC1 in providing stability to the Polβ protein through Polβ/XRCC1 heterodimer formation.
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Affiliation(s)
- Christopher A Koczor
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA; Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Marlo K Thompson
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA; Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Nidhi Sharma
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA; Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
| | - Aishwarya Prakash
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA; Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA.
| | - Robert W Sobol
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA; Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA; Department of Pathology and Laboratory Medicine, Warren Alpert Medical School & Legorreta Cancer Center, Brown University, Providence, RI 02912, USA.
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3
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Soares NL, Vieira HLA. Microglia at the Centre of Brain Research: Accomplishments and Challenges for the Future. Neurochem Res 2021; 47:218-233. [PMID: 34586585 DOI: 10.1007/s11064-021-03456-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/17/2021] [Accepted: 09/20/2021] [Indexed: 02/08/2023]
Abstract
Microglia are the immune guardians of the central nervous system (CNS), with critical functions in development, maintenance of homeostatic tissue balance, injury and repair. For a long time considered a forgotten 'third element' with basic phagocytic functions, a recent surge in interest, accompanied by technological progress, has demonstrated that these distinct myeloid cells have a wide-ranging importance for brain function. This review reports microglial origins, development, and function in the healthy brain. Moreover, it also targets microglia dysfunction and how it contributes to the progression of several neurological disorders, focusing on particular molecular mechanisms and whether these may present themselves as opportunities for novel, microglia-targeted therapeutic approaches, an ever-enticing prospect. Finally, as it has been recently celebrated 100 years of microglia research, the review highlights key landmarks from the past century and looked into the future. Many challenging problems have arisen, thus it points out some of the most pressing questions and experimental challenges for the ensuing century.
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Affiliation(s)
- Nuno L Soares
- Chronic Diseases Research Center (CEDOC) - Faculdade de Ciências Médicas/NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria 130, 1169-056, Lisboa, Portugal.
| | - Helena L A Vieira
- Chronic Diseases Research Center (CEDOC) - Faculdade de Ciências Médicas/NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria 130, 1169-056, Lisboa, Portugal.,Department of Chemistry, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, Universidade Nova de Lisboa, Lisboa, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Lisboa, Portugal
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4
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Vasil'eva IA, Moor NA, Lavrik OI. Effect of Human XRCC1 Protein Oxidation on the Functional Activity of Its Complexes with the Key Enzymes of DNA Base Excision Repair. BIOCHEMISTRY (MOSCOW) 2021; 85:288-299. [PMID: 32564733 DOI: 10.1134/s0006297920030049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Base excision repair (BER) ensures correction of most abundant DNA lesions in mammals. The efficiency of this multistep DNA repair process that can occur via different pathways depends on the coordinated action of enzymes catalyzing its individual steps. The scaffold XRCC1 (X-ray repair cross-complementing protein 1) protein plays an important coordinating role in the repair of damaged bases and apurinic/apyrimidinic (AP) sites via short-patch (SP) BER pathway, as well as in the repair of single-strand DNA breaks. In this study, we demonstrated for the first time in vitro formation of the ternary XRCC1 complex with the key enzymes of SP BER - DNA polymerase β (Polβ) and DNA ligase IIIα (LigIIIα) - using the fluorescence-based technique. It was found that Polβ directly interacts with LigIIIα, but their complex is less stable than the XRCC1-Polβ and XRCC1-LigIIIα complexes. The effect of XRCC1 oxidation and composition of the multiprotein complex on the efficiency of DNA synthesis and DNA ligation during DNA repair has been explored. We found that formation of the disulfide bond between Cys12 and Cys20 residues as a result of XRCC1 oxidation (previously shown to modulate the protein affinity for Polβ), affects the yield of the final product of SP BER and of non-ligated DNA intermediates (substrates of long-patch BER). The effect of XRCC1 oxidation on the final product yield depended on the presence of AP endonuclease 1. Together with the data from our previous work, the results of this study suggest an important role of XRCC1 oxidation in the fine regulation of formation of BER complexes and their functional activity.
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Affiliation(s)
- I A Vasil'eva
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - N A Moor
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - O I Lavrik
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia. .,Novosibirsk State University, Novosibirsk, 630090, Russia
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5
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Howard MJ, Horton JK, Zhao ML, Wilson SH. Lysines in the lyase active site of DNA polymerase β destabilize nonspecific DNA binding, facilitating searching and DNA gap recognition. J Biol Chem 2020; 295:12181-12187. [PMID: 32647014 PMCID: PMC7443498 DOI: 10.1074/jbc.ra120.013547] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/07/2020] [Indexed: 11/06/2022] Open
Abstract
DNA polymerase (pol) β catalyzes two reactions at DNA gaps generated during base excision repair, gap-filling DNA synthesis and lyase-dependent 5´-end deoxyribose phosphate removal. The lyase domain of pol β has been proposed to function in DNA gap recognition and to facilitate DNA scanning during substrate search. However, the mechanisms and molecular interactions used by pol β for substrate search and recognition are not clear. To provide insight into this process, a comparison was made of the DNA binding affinities of WT pol β, pol λ, and pol μ, and several variants of pol β, for 1-nt-gap-containing and undamaged DNA. Surprisingly, this analysis revealed that mutation of three lysine residues in the lyase active site of pol β, 35, 68, and 72, to alanine (pol β KΔ3A) increased the binding affinity for nonspecific DNA ∼11-fold compared with that of the WT. WT pol μ, lacking homologous lysines, displayed nonspecific DNA binding behavior similar to that of pol β KΔ3A, in line with previous data demonstrating both enzymes were deficient in processive searching. In fluorescent microscopy experiments using mouse fibroblasts deficient in PARP-1, the ability of pol β KΔ3A to localize to sites of laser-induced DNA damage was strongly decreased compared with that of WT pol β. These data suggest that the three lysines in the lyase active site destabilize pol β when bound to DNA nonspecifically, promoting DNA scanning and providing binding specificity for gapped DNA.
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Affiliation(s)
- Michael J Howard
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Julie K Horton
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Ming-Lang Zhao
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA.
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6
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Nadalutti CA, Stefanick DF, Zhao ML, Horton JK, Prasad R, Brooks AM, Griffith JD, Wilson SH. Mitochondrial dysfunction and DNA damage accompany enhanced levels of formaldehyde in cultured primary human fibroblasts. Sci Rep 2020; 10:5575. [PMID: 32221313 PMCID: PMC7101401 DOI: 10.1038/s41598-020-61477-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 02/21/2020] [Indexed: 12/17/2022] Open
Abstract
Formaldehyde (FA) is a simple biological aldehyde that is produced inside cells by several processes such as demethylation of DNA and proteins, amino acid metabolism, lipid peroxidation and one carbon metabolism (1-C). Although accumulation of excess FA in cells is known to be cytotoxic, it is unknown if an increase in FA level might be associated with mitochondrial dysfunction. We choose to use primary human fibroblasts cells in culture (foreskin, FSK) as a physiological model to gain insight into whether an increase in the level of FA might affect cellular physiology, especially with regard to the mitochondrial compartment. FSK cells were exposed to increasing concentrations of FA, and different cellular parameters were studied. Elevation in intracellular FA level was achieved and was found to be cytotoxic by virtue of both apoptosis and necrosis and was accompanied by both G2/M arrest and reduction in the time spent in S phase. A gene expression assessment by microarray analysis revealed FA affected FSK cells by altering expression of many genes including genes involved in mitochondrial function and electron transport. We were surprised to observe increased DNA double-strand breaks (DSBs) in mitochondria after exposure to FA, as revealed by accumulation of γH2A.X and 53BP1 at mitochondrial DNA foci. This was associated with mitochondrial structural rearrangements, loss of mitochondrial membrane potential and activation of mitophagy. Collectively, these results indicate that an increase in the cellular level of FA can trigger mitochondrial DNA double-strand breaks and dysfunction.
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Affiliation(s)
- Cristina A Nadalutti
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, 27709, USA
| | - Donna F Stefanick
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, 27709, USA
| | - Ming-Lang Zhao
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, 27709, USA
| | - Julie K Horton
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, 27709, USA
| | - Rajendra Prasad
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, 27709, USA
| | - Ashley M Brooks
- Center for Integrative Bioinformatics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, 27709, USA
| | - Jack D Griffith
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, 27709, USA.
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7
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Vasil’eva IA, Moor NA, Lavrik OI. Role of Oxidation of XRCC1 Protein in Regulation of Mammalian DNA Repair Process. DOKL BIOCHEM BIOPHYS 2020; 489:357-361. [DOI: 10.1134/s1607672919060012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Indexed: 01/27/2023]
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8
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Fang Q, Andrews J, Sharma N, Wilk A, Clark J, Slyskova J, Koczor CA, Lans H, Prakash A, Sobol RW. Stability and sub-cellular localization of DNA polymerase β is regulated by interactions with NQO1 and XRCC1 in response to oxidative stress. Nucleic Acids Res 2020; 47:6269-6286. [PMID: 31287140 PMCID: PMC6614843 DOI: 10.1093/nar/gkz293] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 03/24/2019] [Accepted: 04/11/2019] [Indexed: 12/14/2022] Open
Abstract
Protein–protein interactions regulate many essential enzymatic processes in the cell. Somatic mutations outside of an enzyme active site can therefore impact cellular function by disruption of critical protein–protein interactions. In our investigation of the cellular impact of the T304I cancer mutation of DNA Polymerase β (Polβ), we find that mutation of this surface threonine residue impacts critical Polβ protein–protein interactions. We show that proteasome-mediated degradation of Polβ is regulated by both ubiquitin-dependent and ubiquitin-independent processes via unique protein–protein interactions. The ubiquitin-independent proteasome pathway regulates the stability of Polβ in the cytosol via interaction between Polβ and NAD(P)H quinone dehydrogenase 1 (NQO1) in an NADH-dependent manner. Conversely, the interaction of Polβ with the scaffold protein X-ray repair cross complementing 1 (XRCC1) plays a role in the localization of Polβ to the nuclear compartment and regulates the stability of Polβ via a ubiquitin-dependent pathway. Further, we find that oxidative stress promotes the dissociation of the Polβ/NQO1 complex, enhancing the interaction of Polβ with XRCC1. Our results reveal that somatic mutations such as T304I in Polβ impact critical protein–protein interactions, altering the stability and sub-cellular localization of Polβ and providing mechanistic insight into how key protein–protein interactions regulate cellular responses to stress.
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Affiliation(s)
- Qingming Fang
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Joel Andrews
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Nidhi Sharma
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Anna Wilk
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Jennifer Clark
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Jana Slyskova
- Department of Molecular Genetics, Erasmus MC, Erasmus University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands
| | - Christopher A Koczor
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Hannes Lans
- Department of Molecular Genetics, Erasmus MC, Erasmus University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands.,Oncode Institute, Erasmus MC, Erasmus University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands
| | - Aishwarya Prakash
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
| | - Robert W Sobol
- University of South Alabama Mitchell Cancer Institute, 1660 Springhill Avenue, Mobile, AL 36604, USA
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9
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Giorgio M, Dellino GI, Gambino V, Roda N, Pelicci PG. On the epigenetic role of guanosine oxidation. Redox Biol 2020; 29:101398. [PMID: 31926624 PMCID: PMC6926346 DOI: 10.1016/j.redox.2019.101398] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/23/2019] [Accepted: 12/02/2019] [Indexed: 01/14/2023] Open
Abstract
Chemical modifications of DNA and RNA regulate genome functions or trigger mutagenesis resulting in aging or cancer. Oxidations of macromolecules, including DNA, are common reactions in biological systems and often part of regulatory circuits rather than accidental events. DNA alterations are particularly relevant since the unique role of nuclear and mitochondrial genome is coding enduring and inheritable information. Therefore, an alteration in DNA may represent a relevant problem given its transmission to daughter cells. At the same time, the regulation of gene expression allows cells to continuously adapt to the environmental changes that occur throughout the life of the organism to ultimately maintain cellular homeostasis. Here we review the multiple ways that lead to DNA oxidation and the regulation of mechanisms activated by cells to repair this damage. Moreover, we present the recent evidence suggesting that DNA damage caused by physiological metabolism acts as epigenetic signal for regulation of gene expression. In particular, the predisposition of guanine to oxidation might reflect an adaptation to improve the genome plasticity to redox changes.
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Affiliation(s)
- Marco Giorgio
- Department of Experimental Oncology, European Institute of Oncology-IRCCS, Via Adamello 16, 20139, Milano, Italy; Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131, Padova, Italy.
| | - Gaetano Ivan Dellino
- Department of Experimental Oncology, European Institute of Oncology-IRCCS, Via Adamello 16, 20139, Milano, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
| | - Valentina Gambino
- Department of Experimental Oncology, European Institute of Oncology-IRCCS, Via Adamello 16, 20139, Milano, Italy
| | - Niccolo' Roda
- Department of Experimental Oncology, European Institute of Oncology-IRCCS, Via Adamello 16, 20139, Milano, Italy
| | - Pier Giuseppe Pelicci
- Department of Experimental Oncology, European Institute of Oncology-IRCCS, Via Adamello 16, 20139, Milano, Italy; Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
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10
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Shining light on the response to repair intermediates in DNA of living cells. DNA Repair (Amst) 2019; 85:102749. [PMID: 31790865 DOI: 10.1016/j.dnarep.2019.102749] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/03/2019] [Accepted: 11/08/2019] [Indexed: 11/22/2022]
Abstract
Fluorescently-tagged repair proteins have been widely used to probe recruitment to micro-irradiation-induced nuclear DNA damage in living cells. Here, we quantify APE1 dynamics after micro-irradiation. Markers of DNA damage are characterized and UV-A laser micro-irradiation energy conditions are selected for formation of oxidatively-induced DNA base damage and single strand breaks, but without detectable double strand breaks. Increased energy of laser micro-irradiation, compared with that used previously in our work, enables study of APE1 dynamics at the lesion site. APE1 shows rapid transient kinetics, with recruitment half-time of less than 1 s and dissociation half-time of less than 15 s. In cells co-transfected with APE1 and PARP1, the recruitment half-time of PARP1 was slower than that of APE1, indicating APE1 is a rapid responder to the damage site. While recruitment of APE1 is unchanged in the presence of co-transfected PARP1, APE1 dissociation is 3-fold slower, revealing PARP1 involvement in APE1 dynamics. Further, we find that APE1 dissociation kinetics are strongly modified in the absence of DNA polymerase β (pol β). After unchanged recruitment to the damage site, dissociation of APE1 became undetectable. This indicates a necessary role for pol β in APE1 release after its recruitment to the damage site. These observations represent an advance in our understanding of in vivo dynamics of base excision repair factors APE1, PARP1 and pol β.
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11
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Abstract
Genomic DNA is susceptible to endogenous and environmental stresses that modify DNA structure and its coding potential. Correspondingly, cells have evolved intricate DNA repair systems to deter changes to their genetic material. Base excision DNA repair involves a number of enzymes and protein cofactors that hasten repair of damaged DNA bases. Recent advances have identified macromolecular complexes that assemble at the DNA lesion and mediate repair. The repair of base lesions generally requires five enzymatic activities: glycosylase, endonuclease, lyase, polymerase, and ligase. The protein cofactors and mechanisms for coordinating the sequential enzymatic steps of repair are being revealed through a range of experimental approaches. We discuss the enzymes and protein cofactors involved in eukaryotic base excision repair, emphasizing the challenge of integrating findings from multiple methodologies. The results provide an opportunity to assimilate biochemical findings with cell-based assays to uncover new insights into this deceptively complex repair pathway.
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Affiliation(s)
- William A Beard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
| | - Julie K Horton
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
| | - Rajendra Prasad
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
| | - Samuel H Wilson
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina 27709-2233, USA;
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12
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Moor NA, Lavrik OI. Protein–Protein Interactions in DNA Base Excision Repair. BIOCHEMISTRY (MOSCOW) 2018; 83:411-422. [DOI: 10.1134/s0006297918040120] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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13
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Horton JK, Stefanick DF, Çağlayan M, Zhao ML, Janoshazi AK, Prasad R, Gassman NR, Wilson SH. XRCC1 phosphorylation affects aprataxin recruitment and DNA deadenylation activity. DNA Repair (Amst) 2018; 64:26-33. [DOI: 10.1016/j.dnarep.2018.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/05/2018] [Accepted: 02/08/2018] [Indexed: 11/26/2022]
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14
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Horton JK, Stefanick DF, Zhao ML, Janoshazi AK, Gassman NR, Seddon HJ, Wilson SH. XRCC1-mediated repair of strand breaks independent of PNKP binding. DNA Repair (Amst) 2017; 60:52-63. [PMID: 29100039 PMCID: PMC5696015 DOI: 10.1016/j.dnarep.2017.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 10/03/2017] [Accepted: 10/12/2017] [Indexed: 10/18/2022]
Abstract
Repair of DNA-protein crosslinks and oxidatively damaged DNA base lesions generates intermediates with nicks or gaps with abnormal and blocked 3'-phosphate and 5'-OH ends that prevent the activity of DNA polymerases and ligases. End cleaning in mammalian cells by Tdp1 and PNKP produces the conventional 3'-OH and 5'-phosphate DNA ends suitable for completion of repair. This repair function of PNKP is facilitated by its binding to the scaffold protein XRCC1, and phosphorylation of XRCC1 by CK2 at several consensus sites enables PNKP binding and recruitment to DNA damage. To evaluate this documented repair process, a phosphorylation mutant of XRCC1, designed to eliminate PNKP binding, was stably expressed in Xrcc1-/- mouse fibroblast cells. Analysis of PNKP-GFP accumulation at micro-irradiation induced damage confirmed that the XRCC1 phosphorylation mutant failed to support efficient PNKP recruitment, whereas there was rapid recruitment in cells expressing wild-type XRCC1. Recruitment of additional fluorescently-tagged repair factors PARP-1-YFP, GFF-XRCC1, PNKP-GFP and Tdp1-GFP to micro-irradiation induced damage was assessed in wild-type XRCC1-expressing cells. PARP-1-YFP recruitment was best fit to two exponentials, whereas kinetics for the other proteins were fit to a single exponential. The similar half-times of recruitment suggest that XRCC1 may be recruited with other proteins possibly as a pre-formed complex. Xrcc1-/- cells are hypersensitive to the DNA-protein cross-link inducing agent camptothecin (CPT) and the DNA oxidative agent H2O2 due in part to compromised PNKP-mediated repair. However, cells expressing the PNKP interaction mutant of XRCC1 demonstrated marked reversal of CPT hypersensitivity. This reversal represents XRCC1-dependent repair in the absence of the phosphorylation-dependent PNKP recruitment and suggests either an XRCC1-independent mechanism of PNKP recruitment or a functional back-up pathway for cleaning of blocked DNA ends.
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Affiliation(s)
- Julie K Horton
- Genomic Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Donna F Stefanick
- Genomic Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Ming-Lang Zhao
- Genomic Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Agnes K Janoshazi
- Signal Transduction Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
| | - Natalie R Gassman
- Genomic Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Hannah J Seddon
- Genomic Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Samuel H Wilson
- Genomic Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA.
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15
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Polyzos AA, McMurray CT. Close encounters: Moving along bumps, breaks, and bubbles on expanded trinucleotide tracts. DNA Repair (Amst) 2017; 56:144-155. [PMID: 28690053 PMCID: PMC5558859 DOI: 10.1016/j.dnarep.2017.06.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Expansion of simple triplet repeats (TNR) underlies more than 30 severe degenerative diseases. There is a good understanding of the major pathways generating an expansion, and the associated polymerases that operate during gap filling synthesis at these "difficult to copy" sequences. However, the mechanism by which a TNR is repaired depends on the type of lesion, the structural features imposed by the lesion, the assembled replication/repair complex, and the polymerase that encounters it. The relationships among these parameters are exceptionally complex and how they direct pathway choice is poorly understood. In this review, we consider the properties of polymerases, and how encounters with GC-rich or abnormal structures might influence polymerase choice and the success of replication and repair. Insights over the last three years have highlighted new mechanisms that provide interesting choices to consider in protecting genome stability.
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Affiliation(s)
- Aris A Polyzos
- MBIB Division, Lawrence Berkeley Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States
| | - Cynthia T McMurray
- MBIB Division, Lawrence Berkeley Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, United States.
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16
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Abstract
This introductory article should be viewed as a prologue to the Free Radical Biology & Medicine Special Issue devoted to the important topic of Oxidatively Damaged DNA and its Repair. This special issue is dedicated to Professor Tomas Lindahl, co-winner of the 2015 Nobel Prize in Chemistry for his seminal discoveries in the area repair of oxidatively damaged DNA. In the past several years it has become abundantly clear that DNA oxidation is a major consequence of life in an oxygen-rich environment. Concomitantly, survival in the presence of oxygen, with the constant threat of deleterious DNA mutations and deletions, has largely been made possible through the evolution of a vast array of DNA repair enzymes. The articles in this Oxidatively Damaged DNA & Repair special issue detail the reactions by which intracellular DNA is oxidatively damaged, and the enzymatic reactions and pathways by which living organisms survive such assaults by repair processes.
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Affiliation(s)
- Jean Cadet
- Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine de des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4
| | - Kelvin J A Davies
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, the University of Southern California, Los Angeles, CA 90089-0191, USA; Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, the University of Southern California, Los Angeles, CA 90089-0191, USA.
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