We isolated spontaneous extragenic suppressors of a temperature-sensitive, lethal poly(A) polymerase mutation (pap1-1) in Saccharomyces cerevisiae that restore growth at the restrictive temperature of 30 degrees. Three of five suppressors represent alleles of the PDS2 complementation group. The recessive pds2-1 mutation exerts dominant allele-specific suppression over pap1-1, suggesting a direct functional interaction. The suppressor restores to near normal the steady-state concentrations of various mRNAs and total poly(A) reduced by pap1-1 at 30 degrees. Transcriptional chase experiments detect no reduction in the decay rates of mRNAs in the suppressor strain, suggesting that the restoration of steady-state message levels results from increased stable mRNA synthesis. Molecular cloning shows PDS2 to be allelic to RET1, which encodes the second-largest subunit of RNA polymerase III. We observe alterations in both the length and the steady-state amounts of RNA polymerase III transcripts in pds2-1 strains. Previously identified ret1 alleles do not suppress pap1-1, indicating that the pds2 alleles we isolated represent a specific class of RET1 mutations that suppress pap1-1. Suppression of pap1-1 by mutations in an RNA polymerase III subunit suggests a number of potentially novel interactions between these enzymes.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|