Interplay between mismatch repair and chromatin assembly.
Proc Natl Acad Sci U S A
; 109(6): 1895-900, 2012 Feb 07.
Article
em En
| MEDLINE
| ID: mdl-22232658
ABSTRACT
Single strand nicks and gaps in DNA have been reported to increase the efficiency of nucleosome loading mediated by chromatin assembly factor 1 (CAF-1). However, on mismatch-containing substrates, these strand discontinuities are utilized by the mismatch repair (MMR) system as loading sites for exonuclease 1, at which degradation of the error-containing strand commences. Because packaging of DNA into chromatin might inhibit MMR, we were interested to learn whether chromatin assembly is differentially regulated on heteroduplex and homoduplex substrates. We now show that the presence of a mismatch in a nicked plasmid substrate delays nucleosome loading in human cell extracts. Our data also suggest that, once the mismatch is removed, repair of the single-stranded gap is accompanied by efficient nucleosome loading. We postulated that the balance between MMR and chromatin assembly might be governed by proliferating cell nuclear antigen (PCNA), the processivity factor of replicative DNA polymerases, which is loaded at DNA termini and which interacts with the MSH6 subunit of the mismatch recognition factor MutSα, as well as with CAF-1. We now show that this regulation might be more complex; MutSα and CAF-1 interact not only with PCNA, but also with each other. In vivo this interaction increases during S-phase and may be controlled by the phosphorylation status of the p150 subunit of CAF-1.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Montagem e Desmontagem da Cromatina
/
Reparo de Erro de Pareamento de DNA
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article