Both activation and repression of a-mating-type-specific genes in yeast require transcription factor Mcm1.
Mcm1 is a yeast transcription factor with homologs throughout the metazoa. MCM1 was first identified as a gene involved in maintenance of artificial minichromosomes in yeast. More recently Mcm1 has been shown to serve as a transcriptional regulator of mating-type-specific genes. Biochemical data suggest that Mcm1 coactivates alpha-specific genes and corepresses a-specific genes by binding to a 10-base-pair dyad symmetry element in their upstream regions. We reported previously that an mcm1 point mutation reduced activation of alpha-specific genes but had little effect on the expression of a-specific genes. We now show that another mcm1 allele, which depletes the Mcm1 protein, affects both activation and repression of a-specific genes. The mutant strain remains capable of high levels of pheromone induction of a-specific genes, although with retarded kinetics. Mcm1 joins an increasing number of transcription factors involved in both positive and negative regulation of gene expression.
Elble
R
R
Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853.
Tye
B K
BK
D000483:Alleles; D002872:Chromosome Deletion; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D007700:Kinetics; D000072235:Mating Factor; D026341:Minichromosome Maintenance 1 Protein; D016254:Mutagenesis, Insertional; D010455:Peptides / Q000235:genetics*; D010675:Pheromones / Q000235:genetics; D010957:Plasmids; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D005656:Fungal Proteins; D026341:Minichromosome Maintenance 1 Protein; D010455:Peptides; D010675:Pheromones; D014157:Transcription Factors; D000072235:Mating Factor; D001616:beta-Galactosidase