MutSα maintains the mismatch repair capability by inhibiting PCNA unloading.
Elife
; 52016 07 12.
Article
em En
| MEDLINE
| ID: mdl-27402201
ABSTRACT
Eukaryotic mismatch repair (MMR) utilizes single-strand breaks as signals to target the strand to be repaired. DNA-bound PCNA is also presumed to direct MMR. The MMR capability must be limited to a post-replicative temporal window during which the signals are available. However, both identity of the signal(s) involved in the retention of this temporal window and the mechanism that maintains the MMR capability after DNA synthesis remain unclear. Using Xenopus egg extracts, we discovered a mechanism that ensures long-term retention of the MMR capability. We show that DNA-bound PCNA induces strand-specific MMR in the absence of strand discontinuities. Strikingly, MutSα inhibited PCNA unloading through its PCNA-interacting motif, thereby extending significantly the temporal window permissive to strand-specific MMR. Our data identify DNA-bound PCNA as the signal that enables strand discrimination after the disappearance of strand discontinuities, and uncover a novel role of MutSα in the retention of the post-replicative MMR capability.
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Base de dados:
MEDLINE
Assunto principal:
Antígeno Nuclear de Célula em Proliferação
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Proteína MutS de Ligação de DNA com Erro de Pareamento
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Reparo de Erro de Pareamento de DNA
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article