Hepcidin; Seems to act as a signaling molecule involved in the maintenance of iron homeostasis. Seems to be required in conjunction with HFE to regulate both intestinal iron absorption and iron storage in macrophages. May also have antimicrobial activity (By similarity). Belongs to the hepcidin family.

Cytochrome b reductase 1; Ferric-chelate reductase that reduces Fe(3+) to Fe(2+). Present at the brush border of duodenal enterocytes where it probably reduces dietary Fe(3+) thereby facilitating its transport into the mucosal cells. Uses ascorbate as electron donor. May be involved in extracellular ascorbate recycling in erythrocyte membranes. May also act as a ferrireductase in airway epithelial cells (By similarity).

Transferrin receptor protein 1; Cellular uptake of iron occurs via receptor-mediated endocytosis of ligand-occupied transferrin receptor into specialized endosomes. Endosomal acidification leads to iron release. The apotransferrin-receptor complex is then recycled to the cell surface with a return to neutral pH and the concomitant loss of affinity of apotransferrin for its receptor. Transferrin receptor is necessary for development of erythrocytes and the nervous system (By similarity). Positively regulates T and B cell proliferation through iron uptake (By similarity); Belongs to the [...]

Natural resistance-associated macrophage protein 1; Divalent transition metal (iron and manganese) transporter involved in iron metabolism and host resistance to certain pathogens. Macrophage-specific membrane transport function. Controls natural resistance to infection with intracellular parasites. Pathogen resistance involves sequestration of Fe(2+) and Mn(2+), cofactors of both prokaryotic and eukaryotic catalases and superoxide dismutases, not only to protect the macrophage against its own generation of reactive oxygen species, but to deny the cations to the pathogen for synthesis [...]

Solute carrier family 39 (Zinc transporter), member 14 (Predicted).

Cytoplasmic aconitate hydratase; Iron sensor. Binds a 4Fe-4S cluster and functions as aconitase when cellular iron levels are high. Functions as mRNA binding protein that regulates uptake, sequestration and utilization of iron when cellular iron levels are low. Binds to iron-responsive elements (IRES) in target mRNA species when iron levels are low. Binding of a 4Fe-4S cluster precludes RNA binding; Belongs to the aconitase/IPM isomerase family.

Iron-responsive element-binding protein 2; RNA-binding protein that binds to iron-responsive elements (IRES), which are stem-loop structures found in the 5'-UTR of ferritin, and delta aminolevulinic acid synthase mRNAs, and in the 3'-UTR of transferrin receptor mRNA. Binding to the IRE element in ferritin results in the repression of its mRNA translation. Binding of the protein to the transferrin receptor mRNA inhibits the degradation of this otherwise rapidly degraded mRNA; Belongs to the aconitase/IPM isomerase family.

Solute carrier family 40 protein; May be involved in iron transport and iron homeostasis. Belongs to the ferroportin (FP) (TC 2.A.100) family. SLC40A subfamily.

Metalloreductase STEAP3; Endosomal ferrireductase required for efficient transferrin- dependent iron uptake in erythroid cells. Participates in erythroid iron homeostasis by reducing Fe(3+) to Fe(2+). Also mediates reduction of Cu(2+) to Cu(1+), suggesting that it participates in copper homeostasis. Uses NADP(+) as acceptor. Indirectly involved in exosome secretion by facilitating the secretion of proteins such as TCTP (By similarity). May play a role downstream of p53/TP53 to interface apoptosis and cell cycle progression.