Catalytic and noncatalytic roles of the CtIP endonuclease in double-strand break end resection.
Mol Cell
; 54(6): 1022-1033, 2014 Jun 19.
Article
em En
| MEDLINE
| ID: mdl-24837676
ABSTRACT
The carboxy-terminal binding protein (CtBP)-interacting protein (CtIP) is known to function in 5' strand resection during homologous recombination, similar to the budding yeast Sae2 protein, but its role in this process is unclear. Here, we characterize recombinant human CtIP and find that it exhibits 5' flap endonuclease activity on branched DNA structures, independent of the MRN complex. Phosphorylation of CtIP at known damage-dependent sites and other sites is essential for its catalytic activity, although the S327 and T847 phosphorylation sites are dispensable. A catalytic mutant of CtIP that is deficient in endonuclease activity exhibits wild-type levels of homologous recombination at restriction enzyme-generated breaks but is deficient in processing topoisomerase adducts and radiation-induced breaks in human cells, suggesting that the nuclease activity of CtIP is specifically required for the removal of DNA adducts at sites of DNA breaks.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Nucleares
/
Proteínas de Transporte
/
Endonucleases
/
Quebras de DNA de Cadeia Dupla
/
Reparo do DNA por Junção de Extremidades
/
Reparo de DNA por Recombinação
Limite:
Humans
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article