Iron Homeostasis in Insects

Abstract

Iron is an essential micronutrient for all types of organisms; however, iron has chemical properties that can be harmful to cells. Because iron is both necessary and potentially damaging, insects have homeostatic processes that control the redox state, quantity, and location of iron in the body. These processes include uptake of iron from the diet, intracellular and extracellular iron transport, and iron storage. Early studies of iron-binding proteins in insects suggested that insects and mammals have surprisingly different mechanisms of iron homeostasis, including different primary mechanisms for exporting iron from cells and for transporting iron from one cell to another, and subsequent studies have continued to support this view. This review summarizes current knowledge about iron homeostasis in insects, compares insect and mammalian iron homeostasis mechanisms, and calls attention to key remaining knowledge gaps.

Keywords: ferritin; heme; insect; iron; metal transporter; transferrin.

Figure 1.. Iron transport in mammals and insects.

Some key aspects of iron transport in mammals (A) and insects (B) are shown. Abbreviations: Cp, ceruloplasmin; DCytb, duodenal cytochrome b; DMT1, divalent metal transporter 1; FLVCR, feline leukemia virus subgroup C receptor; HCP1, heme carrier protein 1; HO, Heme Oxygenase; Heph, hephaestin; Mvl, Malvolio, Nemy, No extended memory; STEAP, six-transmembrane epithelial antigen of the prostate; Tsf1, Tranferrin 1; Zip, Zinc-regulated, iron-regulated transporter-like protein. Not shown: PCBP, Poly(rC)-binding protein; ZnT, Zinc Transporter.