Regulation of Iron Uptake and Storage in Non-Erythroid Cells

Coordinate Regulation of Iron Uptake and Storage in Non-Erythroid Cells 

During low levels of intracellular chelatable iron, iron storage declines due to inhibition of ferritin synthesis cellular entry of iron increases due to enhanced transferrin receptor synthesis. An opposing set of events occurs 

IRP levels increase and bind to mRNA-IREs of ferritin and transferrin receptors. 

At high cytosolic mobile iron pool IRP levels decrease causing opposite effects on the mRNAs. 

Coordinate translational regulation of ferritin mRNA and transferrin receptor mRNA in nonerythroid cells. Iron regulatory proteins (IRP) are RNA-binding proteins that bind to iron regulatory elements (IREs). IREs are hairpin structures with loops consisting of CAGUGN sequences and are located at the 5 -untranslated region (UTR) and 3 -UTR for ferritin mRNA and transferrin mRNA, respectively. 

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