Elevated levels of recombinational DNA repair in human somatic cells expressing the Saccharomyces cerevisiae RAD52 gene.

The Saccharomyces cerevisiae RAD52 gene was introduced into the human fibrosarcoma-derived cell line HT1080. Transfected cell lines that expressed the yeast transgene catalyzed inter-plasmid homologous DNA recombination at frequencies approx. 12-fold higher than did control cells. Additional experiments revealed that yeast RAD52 gene expression increased the level of resistance to the DNA damaging agents diepoxybutane, and methyl methanesulfonate, but did not alter sensitivity to ultraviolet radiation. These results indicate that the S. cerevisiae Rad52 protein can function in a human somatic cell background and provide support for the idea that a homologous recombination-based DNA repair process functions in mammalian somatic cells.