Regulation of intracellular localization of human MTH1, OGG1, and MYH proteins for repair of oxidative DNA damage

Author(s):  
Yusaku Nakabeppu
2008 ◽  
Vol 29 (3) ◽  
pp. 794-807 ◽  
Author(s):  
Lyra M. Griffiths ◽  
Dan Swartzlander ◽  
Kellen L. Meadows ◽  
Keith D. Wilkinson ◽  
Anita H. Corbett ◽  
...  

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.


1999 ◽  
Vol 19 (5) ◽  
pp. 3779-3787 ◽  
Author(s):  
Ingrun Alseth ◽  
Lars Eide ◽  
Manuela Pirovano ◽  
Torbjørn Rognes ◽  
Erling Seeberg ◽  
...  

ABSTRACT Endonuclease III from Escherichia coli is the prototype of a ubiquitous DNA repair enzyme essential for the removal of oxidized pyrimidine base damage. The yeast genome project has revealed the presence of two genes in Saccharomyces cerevisiae,NTG1 and NTG2, encoding proteins with similarity to endonuclease III. Both contain the highly conserved helix-hairpin-helix motif, whereas only one (Ntg2) harbors the characteristic iron-sulfur cluster of the endonuclease III family. We have characterized these gene functions by mutant and enzyme analysis as well as by gene expression and intracellular localization studies. Targeted gene disruption of NTG1 and NTG2produced mutants with greatly increased spontaneous and hydrogen peroxide-induced mutation frequency relative to the wild type, and the mutation response was further increased in the double mutant. Both enzymes were found to remove thymine glycol and 2,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine (faPy) residues from DNA with high efficiency. However, on UV-irradiated DNA, saturating concentrations of Ntg2 removed only half of the cytosine photoproducts released by Ntg1. Conversely, 5-hydroxycytosine was removed efficiently only by Ntg2. The enzymes appear to have different reaction modes, as judged from much higher affinity of Ntg2 for damaged DNA and more efficient borhydride trapping of Ntg1 to abasic sites in DNA despite limited DNA binding. Northern blot and promoter fusion analysis showed that NTG1 is inducible by cell exposure to DNA-damaging agents, whereas NTG2 is constitutively expressed. Ntg2 appears to be a nuclear enzyme, whereas Ntg1 was sorted both to the nucleus and to the mitochondria. We conclude that functions of both NTG1 and NTG2 are important for removal of oxidative DNA damage in yeast.


2020 ◽  
Author(s):  
Bin Wang ◽  
Weihong Qiu ◽  
Shijie Yang ◽  
Limin Cao ◽  
Chunmei Zhu ◽  
...  

<a><b>OBJECTIVE: </b></a>Acrylamide exposure from daily-consumed food has raised global concern.<b> </b>We aimed to assess the exposure-response relationships of internal acrylamide exposure with oxidative DNA damage, lipid peroxidation and fasting plasma glucose (FPG) alteration, and investigate the mediating role of oxidative DNA damage and lipid peroxidation in the association of internal acrylamide exposure with FPG. <p><b>RESEARCH DESIGN AND METHODS:</b> FPG and urinary biomarkers of oxidative DNA damage (8-hydroxy-deoxy-guanosine, 8-OHdG), lipid peroxidation (8-iso-prostaglandin-F2α, 8-iso-PGF2α) and acrylamide exposure (N-acetyl-S-(2-carbamoylethyl)-L-cysteine, AAMA; N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine, GAMA) were measured for 3,270 general adults from the Wuhan-Zhuhai cohort. The associations of urinary acrylamide metabolites with 8-OHdG, 8-iso-PGF2α and FPG were assessed by linear mixed models. The mediating roles of 8-OHdG and 8-iso-PGF2α were evaluated by mediation analysis.</p> <p><b>RESULTS:</b> We found significant linear positive dose-response relationships of urinary acrylamide metabolites with 8-OHdG, 8-iso-PGF2α and FPG (except GAMA with FPG), and 8-iso-PGF2α with FPG. Each 1-unit increase in log-transformed level of AAMA, ΣUAAM (AAMA+GAMA) or 8-iso-PGF2α was associated with a 0.17-, 0.15- or 0.23-mmol/L increase in FPG, respectively (<i>P </i>or/and<i> P trend</i><0.05). Each 1% increase in AAMA, GAMA or ΣUAAM was associated with a 0.19%, 0.27% or 0.22% increase in 8-OHdG, respectively, and a 0.40%, 0.48% or 0.44% increase in 8-iso-PGF2α, respectively (<i>P </i>and<i> P trend</i><0.05). Increased 8-iso-PGF2α rather than 8-OHdG significantly mediated 64.29% and 76.92% of the AAMA and ΣUAAM associated-FPG increases, respectively.</p> <p><b>CONCLUSIONS:</b> Exposure of general adult population to acrylamide was associated with FPG elevation, oxidative DNA damage and lipid peroxidation, which in turn partly mediated acrylamide-associated FPG elevation.<b></b></p>


Author(s):  
I. A. Umnyagina ◽  
L. A. Strakhova ◽  
T. V. Blinova

In the blood serum of 70% individuals exposed to harmful factors of the working environment, a high level of oxidative stress and the DNA damage marker 8-Hydroxy-2’-Deoxyguanosine (8-OHdG) were detected.


2012 ◽  
Vol 37 (4) ◽  
pp. 440-448 ◽  
Author(s):  
TRISHNA DEBNATH ◽  
HAI LAN JIN ◽  
MD ABUL HASNAT ◽  
YUNSUK KIM ◽  
NADIRA BINTE SAMAD ◽  
...  

2020 ◽  
pp. 096032712098420
Author(s):  
Ahmet Topal ◽  
Arzu Gergit ◽  
Mustafa Özkaraca

We investigated changes in 8-hydroxy-2-deoxyguanosine (8-OHdG) activity which is a product of oxidative DNA damage, histopathological changes and antioxidant responses in liver and gill tissues of rainbow trout, following a 21-day exposure to three different concentrations of linuron (30 µg/L, 120 µg/L and 240 µg/L). Our results indicated that linuron concentrations caused an increase in LPO levels of liver and gill tissues ( p < 0.05). While linuron induced both increases and decreases in GSH levels and SOD activity, CAT activity was decreased by all concentrations of linuron ( p < 0.05). The immunopositivity of 8-OHdG was detected in the hepatocytes of liver and in the epithelial and chloride cells of the secondary lamellae of the gill tissues. Our results suggested that linuron could cause oxidative DNA damage by causing an increase in 8-OHdG activity in tissues, and it induces histopathological damage and alterations in the antioxidant parameters of the tissues.


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