Specificity of end resection pathways for double-strand break regions containing ribonucleotides and base lesions.
Nat Commun
; 11(1): 3088, 2020 06 18.
Article
em En
| MEDLINE
| ID: mdl-32555206
ABSTRACT
DNA double-strand break repair by homologous recombination begins with nucleolytic resection of the 5' DNA strand at the break ends. Long-range resection is catalyzed by EXO1 and BLM-DNA2, which likely have to navigate through ribonucleotides and damaged bases. Here, we show that a short stretch of ribonucleotides at the 5' terminus stimulates resection by EXO1. Ribonucleotides within a 5' flap are resistant to cleavage by DNA2, and extended RNADNA hybrids inhibit both strand separation by BLM and resection by EXO1. Moreover, 8-oxo-guanine impedes EXO1 but enhances resection by BLM-DNA2, and an apurinic/apyrimidinic site stimulates resection by BLM-DNA2 and DNA strand unwinding by BLM. Accordingly, depletion of OGG1 or APE1 leads to greater dependence of DNA resection on DNA2. Importantly, RNase H2A deficiency impairs resection overall, which we attribute to the accumulation of long RNADNA hybrids at DNA ends. Our results help explain why eukaryotic cells possess multiple resection nucleases.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ribonucleotídeos
/
Quebras de DNA de Cadeia Dupla
Limite:
Humans
Idioma:
En
Revista:
Nat Commun
Assunto da revista:
BIOLOGIA
/
CIENCIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos