CtIP maintains stability at common fragile sites and inverted repeats by end resection-independent endonuclease activity.
Mol Cell
; 54(6): 1012-1021, 2014 Jun 19.
Article
em En
| MEDLINE
| ID: mdl-24837675
ABSTRACT
Chromosomal rearrangements often occur at genomic loci with DNA secondary structures, such as common fragile sites (CFSs) and palindromic repeats. We developed assays in mammalian cells that revealed CFS-derived AT-rich sequences and inverted Alu repeats (Alu-IRs) are mitotic recombination hotspots, requiring the repair functions of carboxy-terminal binding protein (CtBP)-interacting protein (CtIP) and the Mre11/Rad50/Nbs1 complex (MRN). We also identified an endonuclease activity of CtIP that is dispensable for end resection and homologous recombination (HR) at I-SceI-generated "clean" double-strand breaks (DSBs) but is required for repair of DSBs occurring at CFS-derived AT-rich sequences. In addition, CtIP nuclease-defective mutants are impaired in Alu-IRs-induced mitotic recombination. These studies suggest that an end resection-independent CtIP function is important for processing DSB ends with secondary structures to promote HR. Furthermore, our studies uncover an important role of MRN, CtIP, and their associated nuclease activities in protecting CFSs in mammalian cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Nucleares
/
Proteínas de Transporte
/
Sítios Frágeis do Cromossomo
/
Reparo do DNA
/
Quebras de DNA de Cadeia Dupla
/
Sequências Repetidas Invertidas
Limite:
Humans
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Estados Unidos