Ironing out the problem: new mechanisms of iron homeostasis

Trends Biochem Sci. 2005 Aug;30(8):462-8. doi: 10.1016/j.tibs.2005.06.005.


For most organisms, iron is an essential nutrient that is both difficult to acquire from the environment and toxic at high concentration. Therefore, to avoid deprivation or over-abundance of iron, bacteria and eukaryotes have developed a tight regulatory system to keep the metal within a narrow concentration range. Recent work in the bacteria Escherichia coli and in Pseudomonas aeruginosa has demonstrated that small regulatory RNAs function post-transcriptionally to repress iron-using proteins, thereby ensuring that limited iron resources are allocated to crucial cellular functions during iron starvation. Following this discovery, a parallel mechanism that uses a protein and not a small RNA was described in the budding yeast Saccharomyces cerevisiae under iron restriction. The common characteristics of these three different organisms suggest a novel mechanism of iron homeostasis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Down-Regulation
  • Gene Expression Regulation
  • Homeostasis*
  • Humans
  • Iron / metabolism*
  • RNA / genetics
  • Repressor Proteins / metabolism


  • Repressor Proteins
  • RNA
  • Iron