Genetic Requirements for the Single-Strand Annealing Pathway of Double-Strand Break Repair in Saccharomyces Cerevisiae
AUTOR(ES)
Ivanov, E. L.
RESUMO
HO endonuclease-induced double-strand breaks (DSBs) within a direct duplication of Escherichia coli lacZ genes are repaired either by gene conversion or by single-strand annealing (SSA), with >80% being SSA. Previously it was demonstrated that the RAD52 gene is required for DSB-induced SSA. In the present study, the effects of other genes belonging to the RAD52 epistasis group were analyzed. We show that RAD51, RAD54, RAD55, and RAD57 genes are not required for SSA irrespective of whether recombination occurred in plasmid or chromosomal DNA. In both plasmid and chromosomal constructs with homologous sequences in direct orientation, the proportion of SSA events over gene conversion was significantly elevated in the mutant strains. However, gene conversion was not affected when the two lacZ sequences were in inverted orientation. These results suggest that there is a competition between SSA and gene conversion processes that favors SSA in the absence of RAD51, RAD54, RAD55 and RAD57. Mutations in RAD50 and XRS2 genes do not prevent the completion, but markedly retard the kinetics, of DSB repair by both mechanisms in the lacZ direct repeat plasmid, a result resembling the effects of these genes during mating-type (MAT) switching.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1207011Documentos Relacionados
- DNA Length Dependence of the Single-Strand Annealing Pathway and the Role of Saccharomyces cerevisiae RAD59 in Double-Strand Break Repair
- Single-strand interruptions in replicating chromosomes cause double-strand breaks
- Genetic and Physical Analysis of Double-Strand Break Repair and Recombination in Saccharomyces Cerevisiae
- Aberrant Double-Strand Break Repair in rad51 Mutants of Saccharomyces cerevisiae
- Saccharomyces cerevisiae Sin3p facilitates DNA double-strand break repair