Zinc homeostasis in yeast is controlled primarily through the regulation of zinc uptake. Transcription of the ZRT1 and ZRT2 zinc transporters increases in zinc-limited cells, and this induction is dependent on the ZAP1 gene. We hypothesized previously that ZAP1 encodes a zinc-responsive transcriptional activator. Expression of ZAP1 itself increases in zinc-limited cells. This response is also dependent on ZAP1 function through a potential positive autoregulatory mechanism. In this report, we describe the characterization of zinc-responsive elements (ZREs) in the promoters of the ZRT1, ZRT2, and ZAP1 genes. A ZRE consensus sequence, 5'-ACCYYNAAGGT-3', was identified and found to be both necessary and sufficient for zinc-responsive transcriptional regulation. We also demonstrate that ZREs are DNA binding sites for ZAP1. First, a dominant ZAP1 mutation, ZAP1-1(up), which causes increased expression of ZAP1-regulated genes in zinc-replete cells, exerted its effects specifically through the ZREs. Second, electrophoretic mobility shift assays and in vitro DNase I footprint analyses indicated that ZAP1 binds to ZREs in a sequence-specific fashion. These studies demonstrate that ZAP1 plays a direct role in controlling zinc-responsive gene expression in yeast by binding to zinc-responsive elements in the promoters of genes that it regulates.
|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|