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

Nucleic Acids Res. 2003 Aug 1;31(15):4332-44. doi: 10.1093/nar/gkg647.

Abstract

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 fet3Delta arn1-4Delta 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 fep1Delta 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 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*
  • GATA Transcription Factors
  • Gene Expression Regulation, Fungal*
  • Gene Silencing
  • Iron / metabolism*
  • Iron / pharmacology
  • Molecular Sequence Data
  • Repressor Proteins / physiology*
  • Response Elements
  • Schizosaccharomyces / drug effects
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces / metabolism
  • Schizosaccharomyces pombe Proteins / biosynthesis
  • Schizosaccharomyces pombe Proteins / genetics*
  • Schizosaccharomyces pombe Proteins / physiology*
  • Sequence Alignment
  • Siderophores / metabolism*
  • Transcription Factors / physiology*

Substances

  • Carrier Proteins
  • Cation Transport Proteins
  • DNA-Binding Proteins
  • Fep1 protein, S pombe
  • GATA Transcription Factors
  • Repressor Proteins
  • Schizosaccharomyces pombe Proteins
  • Siderophores
  • Str1 protein, S pombe
  • Transcription Factors
  • Iron