The CDC68 gene (also called SPT16) encodes a transcription factor for the expression of a diverse set of genes in the budding yeast Saccharomyces cerevisiae. To identify other proteins that are functionally related to the Cdc68 protein, we searched for genetic suppressors of a cdc68 mutation. Four suppressor genes in which mutations reverse the temperature sensitivity imposed by the cdc68-1 mutation were found. We show here that one of the suppressor genes is the previously reported SAN1 gene; san1 mutations were originally identified as suppressors of a sir4 mutation, implicated in the chromatin-mediated transcriptional silencing of the two mating-type loci HML and HMR. Each san1 mutation, including a san1 null allele, reversed all aspects of the cdc68 mutant phenotype. Conversely, increased copy number of the wild-type SAN1 gene lowered the restrictive temperature for the cdc68-1 mutation. Our findings suggest that the San1 protein antagonizes the transcriptional activator function of the Cdc68 protein. The identification of san1 mutations as suppressors of cdc68 mutations suggests a role for Cdc68 in chromatin structure.
|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|