Hypersensitivity to DNA double-strand breaks associated with PARG deficiency is suppressed by exo-1 and polq-1 mutations in Caenorhabditis elegans.
FEBS J
; 287(6): 1101-1115, 2020 03.
Article
en En
| MEDLINE
| ID: mdl-31593615
Deficiency of either of the two homologs of poly(ADP-ribose) glycohydrolase (PARG), PARG-1 and PARG-2, in Caenorhabditis elegans leads to hypersensitivity to ionizing radiation (IR). In the germ cells of parg-2 mutant worms, the dissipation of recombinase RAD-51 foci was slower than in wild-type (WT) cells, suggesting defects in DNA double-strand break (DSB) repair via homologous recombination (HR). Nevertheless, RPA-1, the large subunit of replication protein A, accumulated faster in parg-2 worms and disappeared earlier than in WT worms. This accelerated RPA-1 accumulation may result from the enhanced expression of exonuclease-1 (EXO-1) after IR treatment. Accordingly, an exo-1 mutation reduced IR sensitivity and accumulation of RPA-1 in parg-2 worms. A mutation of polq-1, encoding for a key factor in the alternative end-joining (Alt-EJ) pathway, suppressed the IR hypersensitivity phenotype of parg-2 worms and normalized the kinetics of RAD-51 dissipation. This indicates that error-prone Alt-EJ may mediate DSB repair in parg-2 worms, causing hypersensitivity to IR. In summary, PARG-2 deficiency in C. elegans causes hyperactive DSB end resection likely through EXO-1 overproduction. DSBs with long single-stranded DNA ends in parg-2 worms are thought to be repaired by Alt-EJ instead of HR, causing genomic instability.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Poli(ADP-Ribosa) Polimerasas
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Caenorhabditis elegans
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ADN Polimerasa Dirigida por ADN
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Exodesoxirribonucleasas
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Roturas del ADN de Doble Cadena
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Mutación
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
FEBS J
Asunto de la revista:
BIOQUIMICA
Año:
2020
Tipo del documento:
Article
Pais de publicación:
Reino Unido