The Saccharomyces cerevisiae Cdc68 transcription activator is antagonized by San1, a protein implicated in transcriptional silencing.

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.
Mesh Terms:
Alleles, Cell Cycle Proteins, Cyclins, Fungal Proteins, Genes, Fungal, Genes, Mating Type, Fungal, Genes, Suppressor, Histones, Mutation, Phenotype, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Trans-Activators, Transcription Factors, Transcription, Genetic, Transcriptional Elongation Factors
Mol. Cell. Biol.
Date: Dec. 01, 1993
Download Curated Data For This Publication
16392
Switch View:
  • Interactions 2