ISSN:
1617-4623
Keywords:
STE12
;
Transcriptional regulation
;
Yeast mating-type control
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
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 α. 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 α1 (a transcriptional activator of α-specific genes) with Ste12p is believed to induce α-specific genes. We isolated and characterized a partially functional ste12 allele (ste12-T50), that is defective only in the activation of α-specific genes. ste12-T50 was isolated as a second-site mutation conferring the a mating phenotype on matα2 mutant cells. In matα2 cells, where due to the lack of repressor, α2, both sets of cell-type-specific genes are expressed, ste12-T50 apparently tips the balance in favor of a-specific gene expression. Thus, matα2 ste12-T50 cells mate like a cells. Additional ste12 mutants that confer the a mating phenotype on matα2 cells have also been isolated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00290136
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