PHYSICAL INTERACTION BETWEEN HUMAN RAD52 AND RPA IS REQUIRED FOR HOMOLOGOUS RECOMBINATION IN MAMMALIAN-CELLS

The yeast RAD52 protein is essential for DNA double-strand break repai r, and meiotic and mitotic recombination, RPA is a protein complex of three subunits (70, 34, and II kDa) that has been shown to be involved in DNA replication, nucleotide excision repair, and homologous recomb ination. Here, we demonstrate a physical interaction between human RAD 52 and RPA in vivo and in vitro, In addition, the domain (amino acids 221-280) in RAD52 protein that mediates the interaction with the 34-kD a subunit of RPA was also determined, Overexpression of mutant RAD52 p roteins lacking the interaction domain (amino acids 221-240, 241-260, and 261-280) failed to induce homologous recombination in monkey cells , We have previously shown that overexpression of human RAD52 induced homologous recombination in these cells, These results suggest that di rect physical interactions between RAD52 and RPA are essential for hom ologous recombination in mammalian cells.