Loss of rereplication control in Saccharomyces cerevisiae results in extensive DNA damage.
To maintain genome stability, the entire genome of a eukaryotic cell must be replicated once and only once per cell cycle. In many organisms, multiple overlapping mechanisms block rereplication, but the consequences of deregulating these mechanisms are poorly understood. Here, we show that disrupting these controls in the budding yeast Saccharomyces cerevisiae rapidly blocks cell proliferation. Rereplicating cells activate the classical DNA damage-induced checkpoint response, which depends on the BRCA1 C-terminus checkpoint protein Rad9. In contrast, Mrc1, a checkpoint protein required for recognition of replication stress, does not play a role in the response to rereplication. Strikingly, rereplicating cells accumulate subchromosomal DNA breakage products. These rapid and severe consequences suggest that even limited and sporadic rereplication could threaten the genome with significant damage. Hence, even subtle disruptions in the cell cycle regulation of DNA replication may predispose cells to the genomic instability associated with tumorigenesis.
Green
Brian M
BM
Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143-2200, USA.
Li
Joachim J
JJ
D018797:Cell Cycle Proteins / Q000378:metabolism; D049109:Cell Proliferation; D064447:Checkpoint Kinase 2; D004249:DNA Damage; D004261:DNA Replication; D004271:DNA, Fungal; D016521:Electrophoresis, Gel, Pulsed-Field; D005434:Flow Cytometry; D005690:Galactose / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal; D016678:Genome; D005838:Genotype; D005947:Glucose / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D015151:Immunoblotting; D008677:Metaphase; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D004718:Saccharomycetales; D013997:Time Factors
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; C441579:MRC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C069930:rad9 protein; D049452:Green Fluorescent Proteins; D064447:Checkpoint Kinase 2; D017346:Protein Serine-Threonine Kinases; C067022:RAD53 protein, S cerevisiae; D005947:Glucose; D005690:Galactose