Aft1p and Aft2p mediate iron-responsive gene expression in yeast through related promoter elements.
The transcription factors Aft1p and Aft2p from Saccharomyces cerevisiae regulate the expression of genes that are involved in iron homeostasis. In vitro studies have shown that both transcription factors bind to an iron-responsive element (FeRE) that is present in the upstream region of genes in the iron regulon. We have used DNA microarrays to distinguish the genes that are activated by Aft1p and Aft2p and to establish for the first time that each factor gives rise to a unique transcriptional profile due to the differential expression of individual iron-regulated genes. We also show that both Aft1p and Aft2p mediate the in vivo expression of FET3 and FIT3 through a consensus FeRE. In addition, both proteins regulate MRS4 via a variant FeRE with Aft2p being the stronger activator from this particular element. Like other paralogous pairs of transcription factors within S. cerevisiae, Aft1p and Aft2p are able to interact with the same promoter elements while maintaining specificity of gene activation.
Rutherford
Julian C
JC
Department of Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
Jaron
Shulamit
S
Winge
Dennis R
DR
D000483:Alleles; D001483:Base Sequence; D015966:Gene Expression Regulation, Fungal; D005822:Genetic Vectors; D007501:Iron / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D020411:Oligonucleotide Array Sequence Analysis; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D020218:Response Elements; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
C090297:AFT1 protein, S cerevisiae; C436328:Aft2 protein, S cerevisiae; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D007501:Iron; D015719:Single-Strand Specific DNA and RNA Endonucleases