Iron sensors

Iron regulatory protein-1 (IRP-1) Iron sensor (cytosol aconitase)... 

Iron Regulatory Proteins 1 and 2 (IRPl and 2) are Important Cytosolic Iron Sensors that Regulate Expression of Ferritin, Transferrin Receptor and Other Iron Metabolism Proteins... 

Interestingly, cytosolic aconitase was recently shown to function also as an iron sensor. Earlier the cytosolic form of aconitase seemed to be an enzyme- unemployed since the majority of other citric acid cycle enzymes are absent from cytosol. It was found, however, that this enzyme plays a crucial role in regulating both the iron delivery to the cell and iron storage [5]. 

Fur is active when bound to ferrous iron in vivo, and other divalent metals confer activity on the protein in vitro [61, 62]. Thus, Fur is an intracellular iron sensor as well as a regulator. Active Fur binds to the promoter of genes under its control at a cij-acting element with a defined consensus sequence [61]. The identification of DNA sequences similar to this so-called Fur box consensus in the upstream region of a gene is often taken as presumptive evidence for its regulation by Fur. With one possible exception [63], the effect of Fur on transcription is repression, and there is no evidence for an activity for apo-Fur. 

Hasinoff, B. B. The intracellular iron sensor calcein is cataly-tically oxidatively degraded by iron(II) in a hydrogen peroxide-dependent reaction. J. Inorg. Biochem. 2003, 95, 157-164. 

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