Transcriptional remodeling in response to iron deprivation in Saccharomyces cerevisiae. Author Minoo Shakoury-Elizeh, John Tiedeman, Jared Rashford, Tracey Ferea, Janos Demeter, Emily Garcia, Ronda Rolfes, Patrick Brown, David Botstein, Caroline Philpott Publication Year 2004 Type Journal Article Abstract The budding yeast Saccharomyces cerevisiae responds to depletion of iron in the environment by activating Aft1p, the major iron-dependent transcription factor, and by transcribing systems involved in the uptake of iron. Here, we have studied the transcriptional response to iron deprivation and have identified new Aft1p target genes. We find that other metabolic pathways are regulated by iron: biotin uptake and biosynthesis, nitrogen assimilation, and purine biosynthesis. Two enzymes active in these pathways, biotin synthase and glutamate synthase, require an iron-sulfur cluster for activity. Iron deprivation activates transcription of the biotin importer and simultaneously represses transcription of the entire biotin biosynthetic pathway. Multiple genes involved in nitrogen assimilation and amino acid metabolism are induced by iron deprivation, whereas glutamate synthase, a key enzyme in nitrogen assimilation, is repressed. A CGG palindrome within the promoter of glutamate synthase confers iron-regulated expression, suggesting control by a transcription factor of the binuclear zinc cluster family. We provide evidence that yeast subjected to iron deprivation undergo a transcriptional remodeling, resulting in a shift from iron-dependent to parallel, but iron-independent, metabolic pathways. Keywords Signal Transduction, Nitrogen, Base Sequence, Molecular Sequence Data, Gene Expression Regulation, Fungal, Saccharomyces cerevisiae, Transcription Factors, Oligonucleotide Array Sequence Analysis, Saccharomyces cerevisiae Proteins, Glutamate Synthase, Iron, Purines, Sulfurtransferases Journal Mol Biol Cell Volume 15 Issue 3 Pages 1233-43 Date Published 03/2004 Alternate Journal Mol. Biol. Cell Google ScholarBibTeXEndNote X3 XML