Fep1 represses expression of the fission yeast Schizosaccharomyces pombe siderophore-iron transport system

• Published in: Nucleic acids research Vol. 31; no. 15; pp. 4332 - 4344
• Main Authors: Pelletier, B, Beaudoin, J, Philpott, C.C, Labbe, S
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.08.2003; Oxford Publishing Limited (England)
• Subjects: Amino Acid Sequence; Base Sequence; Biological Transport; Carrier Proteins - biosynthesis; Carrier Proteins - genetics; Cation Transport Proteins - biosynthesis; Cation Transport Proteins - genetics; Conserved Sequence; DNA-Binding Proteins - physiology; E coli; GATA element; GATA Transcription Factors; gene expression regulation; Gene Expression Regulation, Fungal; Gene Silencing; ion transport; Iron; Iron - metabolism; Iron - pharmacology; Molecular Sequence Data; promoter regions; Repressor Proteins - physiology; Response Elements; Schizosaccharomyces - drug effects; Schizosaccharomyces - genetics; Schizosaccharomyces - metabolism; Schizosaccharomyces pombe; Schizosaccharomyces pombe Proteins - biosynthesis; Schizosaccharomyces pombe Proteins - genetics; Schizosaccharomyces pombe Proteins - physiology; Sequence Alignment; siderophore transporters; Siderophores - metabolism; structural genes; transcription (genetics); transcription factors; Transcription Factors - physiology; transporters; Yeasts
• ISSN: 0305-1048; 1362-4962; 1362-4962
• DOI: 10.1093/nar/gkg647

When iron repletes, Schizosaccharomyces pombe cells repress transcription of genes encoding components involved in the reductive iron transport system. Fep1 mediates this transcriptional control by interacting specifically with GATA‐type cis‐acting elements. To further investigate the role that Fep1 plays in iron homeostasis, we searched for additional Fep1‐regulated genes. We found that str1+ is subject to negative transcriptional regulation, which is exerted through binding of Fep1 to a single GATA element in the str1+ promoter. Introduction of str1+ into a Saccharomyces cerevisiae fet3Δ arn1‐4Δ strain led to assimilation of iron from ferrichrome, revealing that Str1 functions as a siderophore‐iron transporter in S.pombe. We also identified two additional target genes of Fep1, named str2+ and str3+. We demonstrate that the str1+, str2+ and str3+ genes share a common promoter element, 5′‐(A/T)GATAA‐3′. We found that the N‐terminal 241 residue segment of Fep1 expressed in Escherichia coli specifically interacts with the 5′‐(A/T)GATAA‐3′ element present in each of these promoters. Consistent with this, constitutive high level str1+, str2+ and str3+ gene expression was observed in a fep1Δ mutant strain. Taken together, these results demonstrate that Fep1 occupies a central role in coordinating transcriptional regulation of genes encoding components of the reductive and non‐reductive iron transport systems in fission yeast.