Use of DNA Repair Enzymes in Electrochemical Detection of Damage to DNA Bases in Vitro and in Cells

2005 ◽  
Vol 77 (9) ◽  
pp. 2920-2927 ◽  
Author(s):  
Kateřina Cahová-Kuchaříková ◽  
Miroslav Fojta ◽  
Tomáš Mozga ◽  
Emil Paleček
Keyword(s):  
Dna Repair ◽  
Electrochemical Detection ◽  
Dna Bases ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
In Cells

scholarly journals Interaction of antimutagenic 1,4-dihydropyridine AV-153-Na with DNA and DNA-damaging molecules and its impact on DNA repair activity

2017 ◽  
Author(s):  
Elina Leonova ◽  
Evita Rostoka ◽  
Sylvie Sauvaigo ◽  
Edgars Smelovs ◽  
Larisa Baumane ◽  
...  
Keyword(s):  
Dna Repair ◽  
Circular Dichroism ◽  
Hydroxyl Radical ◽  
Binding Mode ◽  
Binding Activity ◽  
Dna Repair Enzymes ◽  
Dna Binding Activity ◽  
Repair Enzymes ◽  
Circular Dichroïsm

1,4-dihydropyridines (1,4-DHP) possess important biochemical and pharmacological properties, including antioxidant and antimutagenic activities. Interaction of some 1,4-DHP with DNA was recently reported. AV-153-Na, an antimutagenic and DNA-repair-enhancing compound appeared to be able to interact with DNA by intercalation. The aim of the current study was to characterize DNA’s capacity for the binding of AV-153-Na, and using different approaches, to test intracellular distribution of the compound, to test the ability of the compound to scavenge peroxynitrite and hydroxyl radical and to assess the ability of the compound to modify the activity of DNA repair enzymes. The DNA binding activity of AV-153-Na was determined by means of fluorescence assay. Titration of the AV-153-Na solutions with DNA gradually increased fluorescence of the solution, indicating direct interactions of the molecule with DNA. AV-153-Na quenched the fluorescence of ethidium bromide and DNA complex, which points to intercalation binding mode. Binding via intercalation was confirmed by means of cyclic voltammetry and circular dichroism spectroscopy. The compound could interact with the four DNA bases in vitro, manifesting a higher affinity to guanine. Some ability to scavenge hydroxyl radical by AV-153-Na was detected by the EPR method. AV-153-Na turned out to be incapable of reacting chemically with peroxynitrite. However, AV-153-Na effectively decreased DNA damage produced by peroxynitrite in cultured HeLa cells. The effects of AV-153-Na on the activity of DNA repair enzymes were tested using Glyco-SPOT and ExSy-SPOT assays. The Glyco-SPOT test essentially revealed an inhibition by AV-153-Na of the enzymes involved thymine glycol repair. Results with ExSy-SPOT chip indicate that AV-153-Na significantly stimulates excision/synthesis repair of 8-oxoguanine (8-oxoG), abasic sites (AP sites) and alkylated bases. Laser confocal scanning fluorescence microscopy demonstrated that within the cells AV-153-Na was found mostly in the cytoplasm; however, a stain in nucleolus was also detected. Binding to cytoplasmic structures might occur due to high affinity of the compound to protein, revealed by fluorescence spectroscopy titration and circular dichroism. Activation of DNA repair enzymes after binding to DNA appears to be the basis for the antimutagenic effects of AV-153-Na.

scholarly journals DNA repair enzymes ALKBH2, ALKBH3, and AlkB oxidize 5-methylcytosine to 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine in vitro

2019 ◽  
Vol 47 (11) ◽  
pp. 5522-5529 ◽  
Author(s):  
Ke Bian ◽  
Stefan A P Lenz ◽  
Qi Tang ◽  
Fangyi Chen ◽  
Rui Qi ◽  
...  
Keyword(s):  
Dna Repair ◽  
Dna Repair Enzymes ◽  
Repair Enzymes

scholarly journals Interaction of antimutagenic 1,4-dihydropyridine AV-153-Na with DNA and DNA-damaging molecules and its impact on DNA repair activity

2017 ◽  
Author(s):  
Elina Leonova ◽  
Evita Rostoka ◽  
Sylvie Sauvaigo ◽  
Edgars Smelovs ◽  
Larisa Baumane ◽  
...  
Keyword(s):  
Dna Repair ◽  
Circular Dichroism ◽  
Hydroxyl Radical ◽  
Binding Mode ◽  
Binding Activity ◽  
Dna Repair Enzymes ◽  
Dna Binding Activity ◽  
Repair Enzymes ◽  
Circular Dichroïsm

1,4-dihydropyridines (1,4-DHP) possess important biochemical and pharmacological properties, including antioxidant and antimutagenic activities. Interaction of some 1,4-DHP with DNA was recently reported. AV-153-Na, an antimutagenic and DNA-repair-enhancing compound appeared to be able to interact with DNA by intercalation. The aim of the current study was to characterize DNA’s capacity for the binding of AV-153-Na, and using different approaches, to test intracellular distribution of the compound, to test the ability of the compound to scavenge peroxynitrite and hydroxyl radical and to assess the ability of the compound to modify the activity of DNA repair enzymes. The DNA binding activity of AV-153-Na was determined by means of fluorescence assay. Titration of the AV-153-Na solutions with DNA gradually increased fluorescence of the solution, indicating direct interactions of the molecule with DNA. AV-153-Na quenched the fluorescence of ethidium bromide and DNA complex, which points to intercalation binding mode. Binding via intercalation was confirmed by means of cyclic voltammetry and circular dichroism spectroscopy. The compound could interact with the four DNA bases in vitro, manifesting a higher affinity to guanine. Some ability to scavenge hydroxyl radical by AV-153-Na was detected by the EPR method. AV-153-Na turned out to be incapable of reacting chemically with peroxynitrite. However, AV-153-Na effectively decreased DNA damage produced by peroxynitrite in cultured HeLa cells. The effects of AV-153-Na on the activity of DNA repair enzymes were tested using Glyco-SPOT and ExSy-SPOT assays. The Glyco-SPOT test essentially revealed an inhibition by AV-153-Na of the enzymes involved thymine glycol repair. Results with ExSy-SPOT chip indicate that AV-153-Na significantly stimulates excision/synthesis repair of 8-oxoguanine (8-oxoG), abasic sites (AP sites) and alkylated bases. Laser confocal scanning fluorescence microscopy demonstrated that within the cells AV-153-Na was found mostly in the cytoplasm; however, a stain in nucleolus was also detected. Binding to cytoplasmic structures might occur due to high affinity of the compound to protein, revealed by fluorescence spectroscopy titration and circular dichroism. Activation of DNA repair enzymes after binding to DNA appears to be the basis for the antimutagenic effects of AV-153-Na.

scholarly journals DASH-type cryptochromes – solved and open questions

2020 ◽  
Vol 401 (12) ◽  
pp. 1487-1493
Author(s):  
Stephan Kiontke ◽  
Tanja Göbel ◽  
Annika Brych ◽  
Alfred Batschauer
Keyword(s):  
Dna Repair ◽  
Circadian Clock ◽  
Blue Light ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Open Questions ◽  
Essential Components ◽  
Repair Activity ◽  
Almost All ◽  
Uv Lesions

AbstractDrosophila, Arabidopsis, Synechocystis, human (DASH)-type cryptochromes (cry-DASHs) form one subclade of the cryptochrome/photolyase family (CPF). CPF members are flavoproteins that act as DNA-repair enzymes (DNA-photolyases), or as ultraviolet(UV)-A/blue light photoreceptors (cryptochromes). In mammals, cryptochromes are essential components of the circadian clock feed-back loop. Cry-DASHs are present in almost all major taxa and were initially considered as photoreceptors. Later studies demonstrated DNA-repair activity that was, however, restricted to UV-lesions in single-stranded DNA. Very recent studies, particularly on microbial organisms, substantiated photoreceptor functions of cry-DASHs suggesting that they could be transitions between photolyases and cryptochromes.

DNA Repair Enzymes in Mammalian Cells

1977 ◽  
pp. 263-322 ◽  
Author(s):  
Errol C. Friedberg ◽  
Kern H. Cook ◽  
James Duncan ◽  
Kristien Mortelmans
Keyword(s):  
Dna Repair ◽  
Mammalian Cells ◽  
Dna Repair Enzymes ◽  
Repair Enzymes

scholarly journals DNA damage shifts circadian clock time via Hausp-dependent Cry1 stabilization

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Stephanie J Papp ◽  
Anne-Laure Huber ◽  
Sabine D Jordan ◽  
Anna Kriebs ◽  
Madelena Nguyen ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Circadian Clock ◽  
Transcriptional Response ◽  
Genotoxic Stress ◽  
Genomic Integrity ◽  
Clock Time ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Specific Protease

The circadian transcriptional repressors cryptochrome 1 (Cry1) and 2 (Cry2) evolved from photolyases, bacterial light-activated DNA repair enzymes. In this study, we report that while they have lost DNA repair activity, Cry1/2 adapted to protect genomic integrity by responding to DNA damage through posttranslational modification and coordinating the downstream transcriptional response. We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time. DNA damage also increases Cry2 interaction with Fbxl3, destabilizing Cry2. Thus, genotoxic stress increases the Cry1/Cry2 ratio, suggesting distinct functions for Cry1 and Cry2 following DNA damage. Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1−/− and blunted in Cry2−/− cells. Furthermore, Cry2−/− cells accumulate damaged DNA. These results suggest that Cry1 and Cry2, which evolved from DNA repair enzymes, protect genomic integrity via coordinated transcriptional regulation.

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