Abnormality in initiation program of DNA replication is monitored by the highly repetitive rRNA gene array on chromosome XII in budding yeast.

ABSTRACT: We have shown previously that perturbation of origin firing in chromosome replication causes DNA lesions and triggers DNA damage checkpoint control, which ensures genomic integrity by stopping cell cycle progression until the lesions are repaired or by inducing cell death if they are not properly repaired. This was based on the observation that the temperature-sensitive phenotype of orc1-4 and orc2-1 mutants required a programmed action of the RAD9-dependent DNA damage checkpoint. Here, we report that DNA lesions in the orc mutants are induced much more quickly and frequently within the rRNA gene (rDNA) locus than at other chromosomal loci upon temperature shift. orc mutant cells with greatly reduced rDNA copy numbers regained the ability to grow at restrictive temperatures, and the checkp

SUBMITTER: Ide S 

PROVIDER: S-EPMC1800804 | biostudies-literature | 2007 Jan

REPOSITORIES: biostudies-literature