Article: article from journal or magazin.
Transcriptional activation mediated by the yeast AP-1 protein is required for normal cadmium tolerance.
Journal of Biological Chemistry
The yeast YAP1 gene encodes a transcriptional regulatory protein that utilizes a basic region-leucine zipper (bZip) DNA-binding domain to recognize its cognate DNA element. A synthetic reporter gene containing a SV40 AP-1 response element (ARE) cloned upstream of a TRP5 promoter-lacZ gene fusion shows yAP-1-dependent transactivation in vivo. Recent work has shown that changes in the gene dosage of this factor can dramatically alter the ability of a cell to tolerate a host of toxic agents including cadmium, cycloheximide, and sulfometuron methyl. We have focused on the YAP1-dependent cadmium resistance as cells that lack a functional YAP1 gene are hypersensitive to this metal. Deletion mapping experiments define two domains in the carboxyl-terminal region of the yAP-1 protein that are required for normal cadmium tolerance and ARE-TRP5-lacZ expression. Single amino acid substitutions in the bZip domain of yAP-1 indicate that this region is required for normal DNA binding and in vivo function of the protein. Replacement of a non-canonical asparagine with leucine in the yAP-1 leucine zipper leads to production of a defective protein. A substitution mutation in the basic domain converts this mutant protein into a dominant negative factor. The ability of yAP-1 to act as a positive regulator of transcription is required for its biological action.
Base Sequence, Blotting, Western, Cadmium/toxicity, Cycloheximide/toxicity, DNA Primers, DNA-Binding Proteins/biosynthesis, DNA-Binding Proteins/isolation & purification, Drug Resistance, Microbial/genetics, Fungal Proteins/metabolism, Gene Expression Regulation, Fungal/drug effects, Genes, Fungal, Molecular Sequence Data, Mutagenesis, Phenotype, Plasmids, Recombinant Proteins/biosynthesis, Recombinant Proteins/isolation & purification, Saccharomyces cerevisiae/drug effects, Saccharomyces cerevisiae/genetics, Saccharomyces cerevisiae Proteins, Sequence Deletion, Sulfonylurea Compounds/toxicity, Transcription Factors/biosynthesis, Transcription Factors/isolation & purification, Transcription, Genetic, Transcriptional Activation, beta-Galactosidase/biosynthesis
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