Schematic representation of the regulation of gene expression by iron http://www.rndsystems.com/heme/hhnews/hh697a1.html
For the IRE on the ferritin mRNA, binding an IBP inhibits translation: apoferritin synthesis is suppressed
For the IRE on the TfR mRNA and ALA-S mRNA, binding an IBP stabilizes the mRNA: synthesis of TfR on the cell membrane and ALA-S within mitochondria is increased