53BP1 nuclear bodies form around DNA lesions generated by mitotic transmission of chromosomes under replication stress.
Nat Cell Biol
; 13(3): 243-53, 2011 Mar.
Article
em En
| MEDLINE
| ID: mdl-21317883
ABSTRACT
Completion of genome duplication is challenged by structural and topological barriers that impede progression of replication forks. Although this can seriously undermine genome integrity, the fate of DNA with unresolved replication intermediates is not known. Here, we show that mild replication stress increases the frequency of chromosomal lesions that are transmitted to daughter cells. Throughout G1, these lesions are sequestered in nuclear compartments marked by p53-binding protein 1 (53BP1) and other chromatin-associated genome caretakers. We show that the number of such 53BP1 nuclear bodies increases after genetic ablation of BLM, a DNA helicase associated with dissolution of entangled DNA. Conversely, 53BP1 nuclear bodies are partially suppressed by knocking down SMC2, a condensin subunit required for mechanical stability of mitotic chromosomes. Finally, we provide evidence that 53BP1 nuclear bodies shield chromosomal fragile sites sequestered in these compartments against erosion. Together, these data indicate that restoration of DNA or chromatin integrity at loci prone to replication problems requires mitotic transmission to the next cell generations.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
DNA
/
Núcleo Celular
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Cromossomos
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Peptídeos e Proteínas de Sinalização Intracelular
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Replicação do DNA
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Mitose
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article