scholarly journals Deletion of OGG1 Results in a Differential Signature of Oxidized Purine Base Damage in mtDNA Regions

2019 ◽  
Vol 20 (13) ◽  
pp. 3302 ◽  
Author(s):  
Guglielmina Chimienti ◽  
Vito Pesce ◽  
Flavio Fracasso ◽  
Francesco Russo ◽  
Nadja Cristhina de Souza-Pinto ◽  
...  
Keyword(s):  
Excision Repair ◽  
Dna Glycosylase ◽  
Mouse Strains ◽  
Mitochondrial Oxidative Stress ◽  
Purine Base ◽  
Endonuclease Iii ◽  
Loop Region ◽  
Age Related ◽  
D Loop ◽  
Base Excision

Mitochondrial oxidative stress accumulates with aging and age-related diseases and induces alterations in mitochondrial DNA (mtDNA) content. Since mtDNA qualitative alterations are also associated with aging, repair of mtDNA damage is of great importance. The most relevant form of DNA repair in this context is base excision repair (BER), which removes oxidized bases such as 8-oxoguanine (8-oxoG) and thymine glycol through the action of the mitochondrial isoform of the specific 8-oxoG DNA glycosylase/apurinic or apyrimidinic (AP) lyase (OGG1) or the endonuclease III homolog (NTH1). Mouse strains lacking OGG1 (OGG1−/−) or NTH1 (NTH1−/−) were analyzed for mtDNA alterations. Interestingly, both knockout strains presented a significant increase in mtDNA content, suggestive of a compensatory mtDNA replication. The mtDNA “common deletion” was not detected in either knockout mouse strain, likely because of the young age of the mice. Formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites accumulated in mtDNA from OGG1−/− but not from NTH1−/− mice. Interestingly, the D-loop region was most severely affected by the absence of OGG1, suggesting that this region may be a hotspot for oxidative damage. Thus, we speculate that mtDNA alterations may send a stress message to evoke cell changes through a retrograde mitochondrial–nucleus communication.

scholarly journals Multiprobe RNase Protection Assay Analysis of mRNA Levels for the Escherichia coli Oxidative DNA Glycosylase Genes under Conditions of Oxidative Stress

2000 ◽  
Vol 182 (19) ◽  
pp. 5416-5424 ◽  
Author(s):  
Christine M. Gifford ◽  
Jeffrey O. Blaisdell ◽  
Susan S. Wallace
Keyword(s):  
Escherichia Coli ◽  
Base Excision Repair ◽  
Excision Repair ◽  
Dna Glycosylase ◽  
Mrna Levels ◽  
Aerobic Growth ◽  
Rnase Protection ◽  
Transcript Levels ◽  
Endonuclease Iii ◽  
Base Excision

ABSTRACT Escherichia coli formamidopyrimidine DNA glycosylase (Fpg), MutY DNA glycosylase, endonuclease VIII, and endonuclease III are oxidative base excision repair DNA glycosylases that remove oxidized bases from DNA, or an incorrect base paired with an oxidized base in the case of MutY. Since genes encoding other base excision repair proteins have been shown to be part of adaptive responses inE. coli, we wanted to determine whether the oxidative DNA glycosylase genes are induced in response to conditions that cause the type of damage their encoded proteins remove. The genesfpg, mutY, nei, and nthencode Fpg, MutY, endonuclease VIII, and endonuclease III, respectively. Multiprobe RNase protection assays were used to examine the transcript levels of these genes under conditions that induce the SoxRS, OxyR, and SOS regulons after a shift from anaerobic to aerobic growth and at different stages along the growth curve. Transcript levels for all four genes decreased as cells progressed from log-phase growth to stationary phase and increased after cells were shifted from anaerobic to aerobic growth. None of the genes were induced by hydrogen peroxide, paraquat, X rays, or conditions that induce the SOS response.

scholarly journals A Novel 3-Methyladenine DNA Glycosylase fromHelicobacter pyloriDefines a New Class within the Endonuclease III Family of Base Excision Repair Glycosylases

2000 ◽  
Vol 275 (26) ◽  
pp. 20077-20083 ◽  
Author(s):  
Eyleen J. O'Rourke ◽  
Catherine Chevalier ◽  
Serge Boiteux ◽  
Agnès Labigne ◽  
Luis Ielpi ◽  
...  
Keyword(s):  
Base Excision Repair ◽  
Excision Repair ◽  
Dna Glycosylase ◽  
New Class ◽  
Endonuclease Iii ◽  
Base Excision

scholarly journals Lesion Recognition and Cleavage of Damage-Containing Quadruplexes and Bulged Structures by DNA Glycosylases

2020 ◽  
Vol 8 ◽  
Author(s):  
Alexandra A. Kuznetsova ◽  
Olga S. Fedorova ◽  
Nikita A. Kuznetsov
Keyword(s):  
Excision Repair ◽  
Repair Process ◽  
Dna Glycosylase ◽  
Promoter Regions ◽  
Dna Structures ◽  
Thymine Glycol ◽  
Abasic Sites ◽  
Endonuclease Iii ◽  
Human Genes ◽  
Base Excision

Human telomeres as well as more than 40% of human genes near the promoter regions have been found to contain the sequence that may form a G-quadruplex structure. Other non-canonical DNA structures comprising bulges, hairpins, or bubbles may have a functionally important role during transcription, replication, or recombination. The guanine-rich regions of DNA are hotspots of oxidation that forms 7,8-dihydro-8-oxoguanine, thymine glycol, and abasic sites: the lesions that are handled by the base excision repair pathway. Nonetheless, the features of DNA repair processes in non-canonical DNA structures are still poorly understood. Therefore, in this work, a comparative analysis of the efficiency of the removal of a damaged nucleotide from various G-quadruplexes and bulged structures was performed using endonuclease VIII-like 1 (NEIL1), human 8-oxoguanine-DNA glycosylase (OGG1), endonuclease III (NTH1), and prokaryotic formamidopyrimidine-DNA glycosylase (Fpg), and endonuclease VIII (Nei). All the tested enzymes were able to cleave damage-containing bulged DNA structures, indicating their important role in the repair process when single-stranded DNA and intermediate non–B-form structures such as bubbles and bulges are formed. Nevertheless, our results suggest that the ability to cleave damaged quadruplexes is an intrinsic feature of members of the H2tH structural family, suggesting that these enzymes can participate in the modulation of processes controlled by the formation of quadruplex structures in genomic DNA.

scholarly journals Replicative Advantage and Tissue-Specific Segregation of RR Mitochondrial DNA Between C57BL/6 and RR Heteroplasmic Mice

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 777-783 ◽  
Author(s):  
Kumiko Takeda ◽  
Seiya Takahashi ◽  
Akira Onishi ◽  
Hirofumi Hanada ◽  
Hiroshi Imai
Keyword(s):  
Embryonic Development ◽  
Nuclear Genome ◽  
Blastocyst Stage ◽  
Mouse Strains ◽  
Cell Stage ◽  
Loop Region ◽  
Age Related ◽  
Stage Embryo ◽  
D Loop ◽  
Development And Differentiation

Abstract To investigate the interactions between mtDNA and nuclear genomes, we produced heteroplasmic maternal lineages by transferring the cytoplasts between the embryos of two mouse strains, C57BL/6 (B6) and RR. A total of 43 different nucleotides exist in the displacement-loop (D-loop) region of mtDNA between B6 and RR. Heteroplasmic embryos were reconstructed by electrofusion using a blastomere from a two-cell stage embryo of one strain and an enucleated blastomere from a two-cell stage embryo of the other strain. Equivalent volumes of both types of mtDNAs were detected in blastocyst stage embryos. However, the mtDNA from the RR strain became biased in the progeny, regardless of the source of the nuclear genome. The RR mtDNA population was very high in most of the tissues examined but was relatively low in the brain and the heart. An age-related increase of RR mtDNA was also observed in the blood. The RR mtDNAs in the reconstructed embryos and in the embryos collected from heteroplasmic mice showed a different segregation pattern during early embryonic development. These results suggest that the RR mtDNA has a replicative advantage over B6 mtDNA during embryonic development and differentiation, regardless of the type of nuclear genome.

scholarly journals Thymine DNA Glycosylase Can Rapidly Excise 5-Formylcytosine and 5-Carboxylcytosine

2011 ◽  
Vol 286 (41) ◽  
pp. 35334-35338 ◽  
Author(s):  
Atanu Maiti ◽  
Alexander C. Drohat
Keyword(s):  
Embryonic Development ◽  
Catalytic Mechanism ◽  
Excision Repair ◽  
Dna Demethylation ◽  
Oxidation Products ◽  
Dna Glycosylase ◽  
Thymine Dna Glycosylase ◽  
Active Demethylation ◽  
Active Dna Demethylation ◽  
Base Excision

Thymine DNA glycosylase (TDG) excises T from G·T mispairs and is thought to initiate base excision repair (BER) of deaminated 5-methylcytosine (mC). Recent studies show that TDG, including its glycosylase activity, is essential for active DNA demethylation and embryonic development. These and other findings suggest that active demethylation could involve mC deamination by a deaminase, giving a G·T mispair followed by TDG-initiated BER. An alternative proposal is that demethylation could involve iterative oxidation of mC to 5-hydroxymethylcytosine (hmC) and then to 5-formylcytosine (fC) and 5-carboxylcytosine (caC), mediated by a Tet (ten eleven translocation) enzyme, with conversion of caC to C by a putative decarboxylase. Our previous studies suggest that TDG could excise fC and caC from DNA, which could provide another potential demethylation mechanism. We show here that TDG rapidly removes fC, with higher activity than for G·T mispairs, and has substantial caC excision activity, yet it cannot remove hmC. TDG excision of fC and caC, oxidation products of mC, is consistent with its strong specificity for excising bases from a CpG context. Our findings reveal a remarkable new aspect of specificity for TDG, inform its catalytic mechanism, and suggest that TDG could protect against fC-induced mutagenesis. The results also suggest a new potential mechanism for active DNA demethylation, involving TDG excision of Tet-produced fC (or caC) and subsequent BER. Such a mechanism obviates the need for a decarboxylase and is consistent with findings that TDG glycosylase activity is essential for active demethylation and embryonic development, as are mechanisms involving TDG excision of deaminated mC or hmC.

scholarly journals Base excision repair enzyme endonuclease III suppresses mutagenesis caused by 8-hydroxy-dGTP

DNA Repair ◽  
2008 ◽  
Vol 7 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Tetsuya Suzuki ◽  
Kazuo Yamamoto ◽  
Hideyoshi Harashima ◽  
Hiroyuki Kamiya
Keyword(s):  
Base Excision Repair ◽  
Excision Repair ◽  
Repair Enzyme ◽  
Endonuclease Iii ◽  
Base Excision

scholarly journals Dynamic Compartmentalization of Base Excision Repair Proteins in Response to Nuclear and Mitochondrial Oxidative Stress

2008 ◽  
Vol 29 (3) ◽  
pp. 794-807 ◽  
Author(s):  
Lyra M. Griffiths ◽  
Dan Swartzlander ◽  
Kellen L. Meadows ◽  
Keith D. Wilkinson ◽  
Anita H. Corbett ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Dna Repair ◽  
Base Excision Repair ◽  
Oxidative Dna Damage ◽  
Excision Repair ◽  
Intracellular Localization ◽  
Genotoxic Stress ◽  
Mitochondrial Oxidative Stress ◽  
Base Excision

ABSTRACT DNAs harbored in both nuclei and mitochondria of eukaryotic cells are subject to continuous oxidative damage resulting from normal metabolic activities or environmental insults. Oxidative DNA damage is primarily reversed by the base excision repair (BER) pathway, initiated by N-glycosylase apurinic/apyrimidinic (AP) lyase proteins. To execute an appropriate repair response, BER components must be distributed to accommodate levels of genotoxic stress that may vary considerably between nuclei and mitochondria, depending on the growth state and stress environment of the cell. Numerous examples exist where cells respond to signals, resulting in relocalization of proteins involved in key biological transactions. To address whether such dynamic localization contributes to efficient organelle-specific DNA repair, we determined the intracellular localization of the Saccharomyces cerevisiae N-glycosylase/AP lyases, Ntg1 and Ntg2, in response to nuclear and mitochondrial oxidative stress. Fluorescence microscopy revealed that Ntg1 is differentially localized to nuclei and mitochondria, likely in response to the oxidative DNA damage status of the organelle. Sumoylation is associated with targeting of Ntg1 to nuclei containing oxidative DNA damage. These studies demonstrate that trafficking of DNA repair proteins to organelles containing high levels of oxidative DNA damage may be a central point for regulating BER in response to oxidative stress.

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