RAD1, a human structural homolog of the Schizosaccharomyces pombe RAD1 cell cycle checkpoint gene

Cell cycle checkpoints are gating mechanisms that govern cell cycle progres sion in the presence of DNA damage and incomplete DNA replication. The Schi zosaccharomyces pombe Rad1 protein is an essential component of cell cycle checkpoints activated by both types of genomic stress. In this study, we re port the isolation of a human homolog of the a pombe RAD1 gene. The hRAD1 p rotein is also similar to the Saccharomyces cerevisiae cell cycle checkpoin t protein Rad17 and the Ustilago maydis 3' --> 5' exonuclease, Rec1. We sho w that human RAD1 partially complements the hydroxyurea and ionizing radiat ion hypersensitivities of a a pombe rad1 mutant, suggesting phylogenetic co nservation of the DNA damage and replication checkpoints. The human RAD1 lo cus was mapped to human chromosome 5p13.2,a locus frequently altered in non small-cell lung cancer and bladder cancer. (C) 1998 Academic Press.