RACH2, A NOVEL HUMAN GENE THAT COMPLEMENTS A FISSION YEAST-CELL CYCLECHECKPOINT MUTATION

We have identified a novel human gene by virtue of its ability to comp lement the rad1-1 checkpoint mutant of Schizosaccharomyces pombe. This gene, called RACH2, rescues the temperature-sensitive lethality of a rad1-1 wee1-50 double mutant of S. pombe. Expression of RACH2 in S. po mbe rad1-1 strains partially restores UV resistance to the rad1-1 muta nt strain. Expression of RACH2 in a rad1-1 cdc25-22 double mutant part ially restores the dose-dependent delay in mitotic entry after irradia tion that is lost in rad1-1 checkpoint-deficient mutants. Overexpressi on of RACH2 in human tissue culture cells induces apoptosis.