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Titolo:
Effect of endogenous carotenoids on "adaptive" mutation in Escherichia coli FC40
Autore:
Bridges, BA; Foster, PL; Timms, AR;
Indirizzi:
Univ Sussex, MRC, Cell Mutat Unit, Brighton BN1 9RR, E Sussex, England Univ Sussex Brighton E Sussex England BN1 9RR BN1 9RR, E Sussex, England Indiana Univ, Dept Biol, Bloomington, IN 47405 USA Indiana Univ Bloomington IN USA 47405 ept Biol, Bloomington, IN 47405 USA
Titolo Testata:
MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS
fascicolo: 1, volume: 473, anno: 2001,
pagine: 109 - 119
SICI:
1386-1964(20010125)473:1<109:EOECO">2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
STARVATION-ASSOCIATED MUTATION; EPISOMAL FRAMESHIFT MUTATION; DNA-POLYMERASE-II; SINGLET-OXYGEN; OXIDATIVE DAMAGE; REVERSION; RECOMBINATION; INVOLVEMENT; CONJUGATION; GENES;
Keywords:
adaptive mutation; carotenoids; singlet oxygen; active oxygen species; frameshift mutations;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
56
Recensione:
Indirizzi per estratti:
Indirizzo: Bridges, BA Univ Sussex, MRC, Cell Mutat Unit, Brighton BN1 9RR, E Sussex,England Univ Sussex Brighton E Sussex England BN1 9RR Sussex, England
Citazione:
B.A. Bridges et al., "Effect of endogenous carotenoids on "adaptive" mutation in Escherichia coli FC40", MUT RES-F M, 473(1), 2001, pp. 109-119

Abstract

The appearance over many days of Lac(+) frameshift mutations in Escherichia coli strain FC40 incubated on lactose selection plates is a classic example of apparent "adaptive" mutation in an episomal gene. We show that endogenously overproduced carotenoids reduce adaptive mutation under selective conditions by a factor of around two. Carotenoids are known to scavenge singlet oxygen suggesting that the accumulation of oxidative base damage may be an integral part of the adaptive mutation phenomenon. If so, the lesion cannot be 7,8-dihydro-8-oxoguanine since adaptive mutation in FC40 is unaffected by mutM and mutY mutations. If active oxygen species such as singlet oxygen are involved in adaptive mutation then they should also induce frameshift mutations in FC40 under non-selective conditions. We show that such mutations can be induced under non-selective conditions by protoporphyrin photosensitisation and that this photodynamic induction is reduced by a factor of just over two when endogenous carotenoids are present. We argue that the involvement of oxidative damage would in no way be inconsistent with current understanding of the mechanism of adaptive mutation and the role of DNA polymerases. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 31/03/20 alle ore 05:10:24