Role of Blm and collaborating factors in recombination and survival following replication stress in Ustilago maydis.
DNA Repair (Amst)
; 8(6): 752-9, 2009 Jun 04.
Article
em En
| MEDLINE
| ID: mdl-19349216
ABSTRACT
Inactivation of the structural gene for the RecQ family member, BLM in human, Sgs1 in budding yeast, or Rqh1 in fission yeast leads to inappropriate recombination, chromosome abnormalities, and disturbed replication fork progression. Studies with yeasts have demonstrated that auxiliary gene functions can contribute in overlapping ways with Sgs1 or Rqh1 to circumvent or overcome lesions in DNA caused by certain genotoxic agents. In the combined absence of these functions, recombination-mediated processes lead to severe loss of fitness. Here we performed a genetic study to determine the role of the Ustilago maydis Blm homolog in DNA repair and in alleviating replication stress. We characterized the single mutant as well as double mutants additionally deleted of genes encoding Srs2, Fbh1, Mus81, or Exo1. Unlike yeasts, neither the blm srs2, blm exo1, nor blm mus81 double mutant exhibited extreme loss of fitness. Inactivation of Brh2, the BRCA2 homolog, suppressed toxicity to hydroxyurea caused by loss of Blm function. However, differential suppression by Brh2 derivatives lacking the canonical DNA-binding region suggests that the particular domain structure comprising this DNA-binding region may be instrumental in promoting the observed hydroxyurea toxicity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Recombinação Genética
/
Ustilago
/
Proteínas Fúngicas
/
Replicação do DNA
/
RecQ Helicases
Idioma:
En
Revista:
DNA Repair (Amst)
Assunto da revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos