The nonhomologous end-joining pathway of DNA repair is required for genomic stability and the suppression of translocations.
Proc Natl Acad Sci U S A
; 97(12): 6630-3, 2000 Jun 06.
Article
en En
| MEDLINE
| ID: mdl-10823907
We have used spectral karyotyping to assess potential roles of three different components of the nonhomologous DNA end-joining pathway in the maintenance of genomic stability in mouse embryonic fibroblasts (MEFs). MEFs homozygous for mutations that inactivate either DNA ligase IV (Lig4) or Ku70 display dramatic genomic instability, even in the absence of exogenous DNA damaging agents. These aberrant events range from chromosomal fragmentation to nonreciprocal translocations that can involve several chromosomes. DNA-dependent protein kinase catalytic subunit deficiency also promotes genome instability. Deficiency for the p53 cell cycle checkpoint protein has little effect on spontaneous levels of chromosomal instability in Lig4-deficient fibroblasts. However, in the context of ionizing radiation treatment, p53 deficiency allowed visualization of massive acute chromosomal destruction in Lig4-deficient MEFs, which in surviving cells manifested as frequent nonreciprocal translocations. We conclude that nonhomologous DNA end-joining plays a crucial role as a caretaker of the mammalian genome, and that an alternative repair pathway exists that often leads to nonreciprocal translocations.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Translocación Genética
/
Aberraciones Cromosómicas
/
Reparación del ADN
Límite:
Animals
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos