Homologous recombination, but not DNA repair, is reduced in vertebrate cells deficient in RAD52.
Mol Cell Biol
; 18(11): 6430-5, 1998 Nov.
Article
in En
| MEDLINE
| ID: mdl-9774659
ABSTRACT
Rad52 plays a pivotal role in double-strand break (DSB) repair and genetic recombination in Saccharomyces cerevisiae, where mutation of this gene leads to extreme X-ray sensitivity and defective recombination. Yeast Rad51 and Rad52 interact, as do their human homologues, which stimulates Rad51-mediated DNA strand exchange in vitro, suggesting that Rad51 and Rad52 act cooperatively. To define the role of Rad52 in vertebrates, we generated RAD52(-/-) mutants of the chicken B-cell line DT40. Surprisingly, RAD52(-/-) cells were not hypersensitive to DNA damages induced by gamma-irradiation, methyl methanesulfonate, or cis-platinum(II)diammine dichloride (cisplatin). Intrachromosomal recombination, measured by immunoglobulin gene conversion, and radiation-induced Rad51 nuclear focus formation, which is a putative intermediate step during recombinational repair, occurred as frequently in RAD52(-/-) cells as in wild-type cells. Targeted integration frequencies, however, were consistently reduced in RAD52(-/-) cells, showing a clear role for Rad52 in genetic recombination. These findings reveal striking differences between S. cerevisiae and vertebrates in the functions of RAD51 and RAD52.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Recombination, Genetic
/
B-Lymphocytes
/
DNA-Binding Proteins
/
DNA Repair
Limits:
Animals
Language:
En
Journal:
Mol Cell Biol
Year:
1998
Document type:
Article
Affiliation country:
Japan