Mammalian polymerase θ promotes alternative NHEJ and suppresses recombination.
Nature
; 518(7538): 254-7, 2015 Feb 12.
Article
en En
| MEDLINE
| ID: mdl-25642960
ABSTRACT
The alternative non-homologous end-joining (NHEJ) machinery facilitates several genomic rearrangements, some of which can lead to cellular transformation. This error-prone repair pathway is triggered upon telomere de-protection to promote the formation of deleterious chromosome end-to-end fusions. Using next-generation sequencing technology, here we show that repair by alternative NHEJ yields non-TTAGGG nucleotide insertions at fusion breakpoints of dysfunctional telomeres. Investigating the enzymatic activity responsible for the random insertions enabled us to identify polymerase theta (Polθ; encoded by Polq in mice) as a crucial alternative NHEJ factor in mammalian cells. Polq inhibition suppresses alternative NHEJ at dysfunctional telomeres, and hinders chromosomal translocations at non-telomeric loci. In addition, we found that loss of Polq in mice results in increased rates of homology-directed repair, evident by recombination of dysfunctional telomeres and accumulation of RAD51 at double-stranded breaks. Lastly, we show that depletion of Polθ has a synergistic effect on cell survival in the absence of BRCA genes, suggesting that the inhibition of this mutagenic polymerase represents a valid therapeutic avenue for tumours carrying mutations in homology-directed repair genes.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Recombinación Genética
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Telómero
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Cromosomas de los Mamíferos
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ADN Polimerasa Dirigida por ADN
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Roturas del ADN de Doble Cadena
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Reparación del ADN por Unión de Extremidades
Tipo de estudio:
Prognostic_studies
Límite:
Animals
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Humans
Idioma:
En
Año:
2015
Tipo del documento:
Article