Characterization of mutations that are synthetic lethal with pol3-13, a mutated allele of DNA polymerase delta in Saccharomyces cerevisiae.
The pol3-13 mutation is located in the C-terminal end of POL3, the gene encoding the catalytic subunit of polymerase delta, and confers thermosensitivity onto the Saccharomyces cerevisiae mutant strain. To get insight about DNA replication control, we performed a genetic screen to identify genes that are synthetic lethal with pol3-13. Mutations in genes encoding the two other subunits of DNA polymerase delta (HYS2, POL32) were identified. Mutations in two recombination genes (RAD50, RAD51) were also identified, confirming that homologous recombination is necessary for pol3-13 mutant strain survival. Other mutations were identified in genes involved in repair and genome stability (MET18/ MMS19), in the control of origin-firing and/or transcription (ABF1, SRB7), in the S/G2 checkpoint (RAD53), in the Ras-cAMP signal transduction pathway (MKS1), in nuclear pore metabolism (SEH1), in protein degradation (DOC1) and in folding (YDJ1). Finally, mutations in three genes of unknown function were isolated (NBP35, DRE2, TAH18). Synthetic lethality between pol3-13 and each of the three mutants pol32, mms19 and doc1 could be suppressed by a rad18 deletion, suggesting an important role of ubiquitination in DNA replication control. We propose that the pol3-13 mutant generates replicative problems that need both homologous recombination and an intact checkpoint machinery to be overcome.
Chanet
Roland
R
Institut Curie Recherche, CNRS UMR2027/Institut Curie, Bât. 110, Centre Universitaire, 91405 Orsay Cédex, France. Roland.Chanet@curie.u-psud.fr
Heude
Martine
M
D002874:Chromosome Mapping; D004252:DNA Mutational Analysis; D004258:DNA Polymerase III / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D010957:Plasmids; D011995:Recombination, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction / Q000235:genetics; D025801:Ubiquitin / Q000235:genetics
D005656:Fungal Proteins; C491232:POL3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; D004258:DNA Polymerase III