Title: | A ste12 allele having a differential effect on a versus alpha cells |
Author(s): | La Roche SD; Shafer BK; Strathern JN; |
Address: | "Laboratory of Eukaryotic Gene Expression, NCI-Frederick Cancer Research and Development Center, ABL-Basic Research Program, Maryland 21702-1201" |
ISSN/ISBN: | 0026-8925 (Print) 0026-8925 (Linking) |
Abstract: | "The transcriptional activator Ste12p is a key component of the yeast pheromone response pathway: phosphorylated as a consequence of signal transduction, it activates transcription of genes that promote mating and the subsequent fusion of the two cell types a and alpha. Activation by Ste12p requires three types of protein-protein interaction between DNA-binding activator proteins: (1) Ste12p by itself can induce non-cell-type-specific genes involved in mating; (2) cooperation of the transactivator Mcm1p with Ste12p induces a-specific genes; and (3) formation of a complex of the activator proteins Mcm1p and alpha 1 (a transcriptional activator of alpha-specific genes) with Ste12p is believed to induce alpha-specific genes. We isolated and characterized a partially functional ste12 allele (ste12-T50), that is defective only in the activation of alpha-specific genes. ste12-T50 was isolated as a second-site mutation conferring the a mating phenotype on mat alpha 2 mutant cells. In mat alpha 2 cells, where due to the lack of repressor, alpha 2, both sets of cell-type-specific genes are expressed, ste12-T50 apparently tips the balance in favor of a-specific gene expression. Thus, mat alpha 2 ste12-T50 cells mate like a cells. Additional ste12 mutants that confer the a mating phenotype on mat alpha 2 cells have also been isolated" |
Keywords: | "Alleles Cell Line DNA-Binding Proteins/genetics/metabolism Fungal Proteins/*genetics/metabolism *Gene Expression Regulation, Fungal *Genes, Fungal Minichromosome Maintenance 1 Protein Phenotype *Point Mutation Saccharomyces cerevisiae/genetics/physiology;" |
Notes: | "MedlineLa Roche, S D Shafer, B K Strathern, J N eng N01-CO-74101/CO/NCI NIH HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. Germany 1995/01/06 Mol Gen Genet. 1995 Jan 6; 246(1):80-90. doi: 10.1007/BF00290136" |