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Titolo:
INACTIVATION OF OGG1 INCREASES THE INCIDENCE OF G-CENTER-DOT-C-]T-CENTER-DOT-A TRANSVERSIONS IN SACCHAROMYCES-CEREVISIAE - EVIDENCE FOR ENDOGENOUS OXIDATIVE DAMAGE TO DNA IN EUKARYOTIC CELLS
Autore:
THOMAS D; SCOT AD; BARBEY R; PADULA M; BOITEUX S;
Indirizzi:
CNRS,UMR217,BP6 F-92265 FONTENAY ROSES FRANCE CNRS,UMR217 F-92265 FONTENAY ROSES FRANCE CNRS,CTR GENET MOL F-91198 GIF SUR YVETTE FRANCE CEA,LAB RADIOBIOL DNA,DEPT RADIOBIOL & RADIOPATHOL F-92265 FONTENAY ROSES FRANCE UNIV COLL SWANSEA,SCH BIOL SCI SWANSEA SA2 8PP W GLAM WALES
Titolo Testata:
MGG. Molecular & general genetics
fascicolo: 2, volume: 254, anno: 1997,
pagine: 171 - 178
SICI:
0026-8925(1997)254:2<171:IOOITI>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
APURINIC APYRIMIDINIC SITES; COLI FPG PROTEIN; ESCHERICHIA-COLI; SUBSTRATE-SPECIFICITY; 8-HYDROXYGUANINE 7,8-DIHYDRO-8-OXOGUANINE; GLYCOSYLASE; MUTAGENESIS; REPAIR; 8-OXOGUANINE; RADIATION;
Keywords:
SACCHAROMYCES CEREVISIAE; DNA REPAIR; G-CENTER-DOT-C-]T-CENTER-DOT-A TRANSVERSIONS; 8-OXOGUANINE; OGG1 GENE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
39
Recensione:
Indirizzi per estratti:
Citazione:
D. Thomas et al., "INACTIVATION OF OGG1 INCREASES THE INCIDENCE OF G-CENTER-DOT-C-]T-CENTER-DOT-A TRANSVERSIONS IN SACCHAROMYCES-CEREVISIAE - EVIDENCE FOR ENDOGENOUS OXIDATIVE DAMAGE TO DNA IN EUKARYOTIC CELLS", MGG. Molecular & general genetics, 254(2), 1997, pp. 171-178

Abstract

The OGG1 gene of Saccharomyces cerevisiae encodes a DNA glycosylase that excises 7,8-dihydro-8-oxoguanine (8-OxoG) and ,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine To investigate the biological role of the OGG1 gene, mutants were constructed by partial deletion of the coding sequence and insertion of marker genes, yielding ogg1::TRP1 and ogg1::URA3 mutant strains. The disruption of the OGG1 gene does not compromise the viability of haploid cells, therefore it is not an essentialgene. The capacity to repair 8-OxoG has been measured in cell-free extracts of wild-type and ogg1 strains using a 34mer DNA fragment containing a single 8-OxoG residue paired with a cytosine (8-OxoG/C) as a substrate. Cell-free extracts of the wild-type strain efficiently cleavethe 8-OxoG-containing strand of the 8-OxoG/C duplex. In contrast, cell-free extracts of the Ogg1-deficient strain have no detectable activity that can cleave the 8-OxoG/C duplex. The biological properties of the ogg1 mutant have also been investigated. The results show that the ogg1 disruptant is not hypersensitive to DNA-damaging agents such as ultraviolet light at 254 nm, hydrogen peroxide or methyl methanesulfonate. However, the ogg1 mutant exhibits a mutator phenotype. When compared to those of a wildtype strain, the frequencies of mutation to canavanine resistance (Can(R)) and reversion to Lys(+) are sevenfold and tenfold higher for the ogg1 mutant strain, respectively. Moreover, usinga specific tester system, we show that the Ogg1-deficient strain displays a 50-fold increase in spontaneously occurring G . C-->T . A transversions compared to the wild-type strain. The five other base substitution events are not affected by the disruption of the OGG1 gene. These results strongly suggest that endogeneous reactive oxygen species cause DNA damage and that the excision of 8-OxoG catalyzed by the Ogg1 protein contributes to the maintenance of genetic stability in S. cerevisiae.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 15/07/20 alle ore 08:19:47