In the yeast Saccharomyces cerevisiae, expression of alpha-specific genes is governed by the MAT alpha 1 and MCM1 gene products. MAT alpha 1 and MCM1 bind cooperatively to PQ elements upstream of alpha-specific genes. The PQ element not only directs alpha-specific expression but can also direct gene induction in response to treatment with a-mating pheromone. We have used gene fusions to investigate whether induction conferred by the PQ box is mediated through either MAT alpha 1 or MCM1, or a combination of both. When MCM1 is fused to the DNA-binding domain of the bacterial repressor LexA, this fusion protein is capable of trans-activating a lacZ reporter gene driven by a LexA operator. However, the transcriptional activity of the MCM1-LexA fusion is not further enhanced by treatment of cells with a-factor. A MAT alpha 1-LexA fusion protein is also capable of trans-activation through a LexA operator. Moreover, the activity of the MAT alpha 1-LexA fusion protein can be further induced by treatment with a-factor. When progressive deletions are made from the amino terminus of MAT alpha 1 in the fusion protein, the basal level of trans-activation progressively decreases, but the inducibility of the fusion protein increases. MAT alpha 1-LexA fusion proteins, which have greater than or equal to 57 amino acids deleted from the amino terminus of MAT alpha 1 are not capable of trans-activation. In addition, the activity of the MAT alpha 1-LexA fusion protein is dependent on the functions of the STE7, STE11, and STE12 genes that encode components of the pheromone response pathway.
|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||Reference||Annotation Extension|
|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||Conditions||Strain||Source||Reference|