The Leu3 protein of yeast is a dual-function regulator, stimulating transcription when the inducer alpha-isopropylmalate (alpha-IPM) is present and suppressing transcription when the inducer is absent. Here we show that Leu3p retains both its positive and negative regulatory properties when expressed in mammalian cells or when added to a mammalian nuclear extract. Alpha-IPM stimulates reporter gene expression 15-20-fold, both in vivo and in vitro. The concentration of alpha-IPM required for half-maximal stimulation in vitro is 2.5 x 10(-4) M. No yeast-specific factors other than Leu3p itself are required for up- or down-regulation. Since alpha-IPM is not metabolized in mammalian cells, the Leu3p-alpha-IPM system might be useful in gene therapy and other studies as a highly specific, externally controlled on/off switch of gene expression.
|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|