Substrate specificity of the Escherichia coli Fpg protein formamidopyrimidine-DNA glycosylase: excision of purine lesions in DNA produced by ionizing radiation or photosensitization

Boiteux, Serge; Gajewski, Ewa; Laval, Jacques; Dizdaroğlu, Miral

doi:10.1021/bi00116a016

Cited by 604 publications

(385 citation statements)

References 43 publications

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“…In the modified comet assays, T cells embedded on slides were treated with either formamidopyrimidine glycosylase (FPG), which recognises oxidatively modified purines (Boiteux et al, 1992), or with endonuclease III (ENDO III), which recognises oxidatively modified pyrimidines (Asahara et al, 1989). These enzymes nick DNA at the sites of oxidatively damaged nucleotides, creating single-strand breaks which can be detected with the alkaline comet assay.…”

Section: Measurement Of Dna Damage: Single Cell Gel Electrophoresis (mentioning

confidence: 99%

Investigation of systemic folate status, impact of alcohol intake and levels of DNA damage in mononuclear cells of breast cancer patients

et al. 2005

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Folate is required for DNA synthesis, repair and methylation. Low folate status has been implicated in carcinogenesis, possibly as a result of higher rate of genetic damage. The aim of this study is to compare folate status and levels of DNA damage between breast cancer and benign breast disease control patients. Fasting blood samples from 64 histologically confirmed untreated breast cancer patients (mean age 57 years) and 30 benign breast disease control patients (mean age 51 years) were obtained. Red cell folate (RCF) and plasma homocysteine were measured. Mononuclear cells (MNC) were isolated for genetic damage analysis using the basic alkaline comet assay. Results are expressed as tail moment. Data were log transformed as appropriate before analysis for normalisation purposes. The geometric mean (95% confidence interval) of RCF (ng ml À1 ) in breast cancer patients was 339.07 (333.3 -404.6) vs 379.5 (335.8 -505.2) in control patients (P ¼ 0.24). Corresponding plasma homocysteine concentrations (mmol l À1 ) were 11.9 (10.6 -16.4) vs 10.1 (9.3 -11.9) (P ¼ 0.073), respectively. The mean tail moment (s.d.) of DNA damage in MNC of breast cancer patients detected by the basic comet assay was 1.4 (0.66) vs -0.17 (0.79) in controls (Po0.0001, t-test), the modified comet assay 'endonuclease III (Endo III)' was 1.7 (0.70) vs 0.86 (0.81) (Po0.0001, t-test), and the modified comet assay 'formamidopyrimidine glycosylase (FPG)' was 1.6 (0.62) vs 0.99 (0.94) (Po0.0001, t-test). There was a significant negative correlation between RCF levels and DNA damage detected by modified comet assay 'FPG' (Pearson Correlation Coefficient r 2 ¼ À0.26, P ¼ 0.02) and DNA damage was found to be significantly higher in MNC of breast cancer patients compared to benign breast disease control patients. Breast cancer patients tended to have lower RCF levels and higher levels of plasma homocysteine, but these differences were not significant. The study provides preliminary evidence that reduced folate status may be implicated in the aetiology of breast cancer perhaps by increasing the in vivo level of genetic instability.

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Section: Measurement Of Dna Damage: Single Cell Gel Electrophoresis (mentioning

confidence: 99%

Investigation of systemic folate status, impact of alcohol intake and levels of DNA damage in mononuclear cells of breast cancer patients

et al. 2005

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“…The presence of oh 8 Gua in DNA causes G:C to T:A transversion, since oh 8 Gua directs the incorporation of cytosine and adenine nucleotides opposite the lesion. To prevent the mutagenic e ect of oh 8 Gua, three DNA repair enzymes (MutM, MutY and MutT proteins) exist in Escherichia coli (E. coli) (Tchou et al, 1991;Boiteux et al, 1992;Au et al, 1989;Michaels et al, 1991Maki and Sekiguchi, 1992). Recently, the OGG1 gene of Saccharomyces cerevisiae (yOGG1) was cloned as being a functional yeast homologue of the bacterial mutM gene (van der Nash et al, 1996).…”

mentioning

confidence: 99%

Genetic polymorphisms and alternative splicing of the hOGG1 gene, that is involved in the repair of 8-hydroxyguanine in damaged DNA

Kohno¹,

Shinmura

Tosaka³

et al. 1998

Oncogene

387

309

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The hOGG1 gene encodes a DNA glycosylase that excises 8-hydroxyguanine (oh 8 Gua) from damaged DNA. Structural analyses of the hOGG1 gene and its transcripts were performed in normal and lung cancer cells. Due to a genetic polymorphism at codon 326, hOGG1-Ser 326 and hOGG1-Cys 326 proteins were produced in human cells. Activity in the repair of oh 8 Gua was greater in hOGG1-Ser 326 protein than in hOGG1-Cys 326 protein in the complementation assay of an E. coli mutant defective in the repair of oh 8 Gua. Two isoforms of hOGG1 transcripts produced by alternative splicing encoded distinct hOGG1 proteins: one with and the other without a putative nuclear localization signal. Loss of heterozygosity at the hOGG1 locus was frequently (15/ 23, 62.2%) detected in lung cancer cells, and a cell line NCI-H526 had a mutation leading to the formation of the transcripts encoding a truncated hOGG1 protein. However, the oh 8 Gua levels in nuclear DNA were similar among lung cancer cells and leukocytes irrespective of the type of hOGG1 proteins expressed. These results suggest that the oh 8 Gua levels are maintained at a steady level, even though multiple hOGG1 proteins are produced due to genetic polymorphisms, mutations and alternative splicing of the hOGG1 gene.

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“…In Escherichia coli, the Fpg protein is responsible for the removal of 8-oxoG from DNA (40,41). Fpg is a DNA glycosylase with an associated AP lyase activity.…”

Section: Discussionmentioning

confidence: 99%

An Oxidative Damage-specific Endonuclease from Rat Liver Mitochondria

Croteau

Rhys

Hudson

et al. 1997

Journal of Biological Chemistry

147

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Reactive oxygen species have been shown to generate mutagenic lesions in DNA. One of the most abundant lesions in both nuclear and mitochondrial DNA is 7,8-dihydro-8-oxoguanine (8-oxoG). We report here the partial purification and characterization of a mitochondrial oxidative damage endonuclease (mtODE) from rat liver that recognizes and incises at 8-oxoG and abasic sites in duplex DNA. Rat liver mitochondria were purified by differential and Percoll gradient centrifugation, and mtODE was extracted from Triton X-100-solubilized mitochondria. Incision activity was measured using a radiolabeled double-stranded DNA oligonucleotide containing a unique 8-oxoG, and reaction products were separated by polyacrylamide gel electrophoresis. Gel filtration chromatography predicts mtODE's molecular mass to be between 25 and 30 kDa. mtODE has a monovalent cation optimum between 50 and 100 mM KCl and a pH optimum between 7.5 and 8. mtODE does not require any co-factors and is active in the presence of 5 mM EDTA. It is specific for 8-oxoG and preferentially incises at 8-oxoG:C base pairs. mtODE is a putative 8-oxoG glycosylase/lyase enzyme, because it can be covalently linked to the 8-oxoG oligonucleotide by sodium borohydride reduction. Comparison of mtODE's activity with other known 8-oxoG glycosylases/lyases and mitochondrial enzymes reveals that this may be a novel protein.Reactive oxygen species are generated in cells as a by-product of cellular respiration. Reactive oxygen species react with proteins, lipids and DNA causing cellular damage. When DNA is the target, a variety of DNA adducts are formed. Among these, 8-oxoG is one of the most abundant lesions generated (1, 2). 8-oxoG 1 is considered to be a premutagenic lesion because it can mispair with adenine during DNA replication (3-5). In the absence of DNA repair, this mispairing results in G to T transversion mutations. Since many reactive oxygen species are generated by oxidative processes that occur in mitochondria, it is of great interest to understand the oxidative DNA damage processing in these organelles.Mitochondrial DNA (mtDNA) is composed of a 16.5-kilobase pair circular genome, encoding 13 structural genes, 22 tRNAs, and two rRNAs. The DNA lies in close proximity to the free radical-producing electron transport chain, and it has been reported that mtDNA contains a higher level of oxidative DNA damage than nuclear DNA (6). Since mtDNA is subjected to relatively high levels of oxidative damage, mitochondria need DNA repair mechanisms to maintain their DNA genomes.Mitochondrial DNA repair mechanisms differ from those in the nucleus. Evidence to suggest that mitochondria lacked DNA repair mechanisms came from the observation that UV damage is not repaired in mitochondria (7, 8), while it is efficiently processed in the nucleus by nucleotide excision repair. In addition, damage caused by cisplatin and nitrogen mustard, agents that are known to induce DNA adducts that are substrates for the nuclear nucleotide excision repair pathway, is inefficiently repaired in m...

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Substrate specificity of the Escherichia coli Fpg protein formamidopyrimidine-DNA glycosylase: excision of purine lesions in DNA produced by ionizing radiation or photosensitization

Cited by 604 publications

References 43 publications

Investigation of systemic folate status, impact of alcohol intake and levels of DNA damage in mononuclear cells of breast cancer patients

Investigation of systemic folate status, impact of alcohol intake and levels of DNA damage in mononuclear cells of breast cancer patients

Genetic polymorphisms and alternative splicing of the hOGG1 gene, that is involved in the repair of 8-hydroxyguanine in damaged DNA

An Oxidative Damage-specific Endonuclease from Rat Liver Mitochondria

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