Table 1.
Some mammalian proteins of iron transport and its regulation
| Protein | Protein abbreviation | Gene symbola | Function/role in iron metabolism | Consequence of mutation or deletion |
|---|---|---|---|---|
| Iron uptake | ||||
| Transferrin | Tf | TF | Plasma iron transport |
Iron deficiency anemia with tissue iron overload Human disease: atransferrinemia |
| Transferrin receptor 1 | TfR1 | TFRC | Internalization of diferric transferrin | Embryonic lethality in homozygote. Mild anemia in heterozygotes. |
| Divalent metal-ion transporter 1 | DMT1 | SLC11A2 | Ferrous iron importer |
Iron deficiency anemia Human disease: refractory hypochromic, microcytic anemia |
| Six transmembrane epithelial antigen of prostate protein 3 | STEAP3 | STEAP3 | Iron reductase of erythroid cells | Iron deficiency anemia |
| Exocyst complex component 6 | SEC15L1 | EXOC6 | Vesicle trafficking | Iron deficiency anemia |
| Duodenal cytochrome B | DCYTB | CYBRD1 | Enterocyte brush border reductase | No overt phenotype |
| Iron recovery | ||||
| Hemopexin | HPX | HPX | Heme binding | No phenotype unless stressed by hemolysis; then extensive renal damage |
| Haptoglobin | HP | HP | Hemoglobin binding | No phenotype unless stressed by hemolysis; then extensive renal damage |
| Iron export | ||||
| Ferroportin | FPN | SLC40A1 | Ferrous iron exporter |
Iron overload in heterozygous state; embryonic lethality in homozygotes Human disease: hemochromatosis type 4 |
| Ceruloplasmin | Cp | CP | Iron oxidase |
Iron overload; CNS dysfunction Human disease: aceruloplasminemia |
| Hephaestin | Hp | HEPH | Iron oxidase (gut and CNS) | Iron deficiency anemia |
| Feline leukemia virus, type C, receptor | FLVCR | FLVCR1 | Heme export protein | Embryonic lethality. Erythropoietic and developmental abnormalities |
| Mitochondrial iron transport | ||||
| Mitoferrin | MFRN | SLC25A37 | Mitochondrial iron importer | Iron deficiency anemia; Erythroid maturation arrest |
| ABC transporter type B7 | ABCB7 | ABCB7 | Mitochondrial Fe–S export |
Mitochondrial iron loading Human disease: X-linked sideroblastic anemia |
| Cellular regulation | ||||
| Iron regulatory protein 1 | IRP1 | ACO1 | Iron-dependent RNA binding protein | Negligible. Some abnormalities in brown fat and kidney. |
| Iron regulatory protein 2 | IRP2 | IREB2 | Iron-dependent RNA binding protein | Anemia; CNS abnormalities of varying severity |
| Systemic regulation | ||||
| Hepcidin | HEPC | HAMP | Regulator of iron release into plasma |
Severe iron overload Human disease: hemochromatosis type 2B |
| Hemochromatosis protein | HFE | HFE | Regulator of hepcidin |
Iron overload Human disease: hemochromatosis type 1 |
| Transferrin receptor 2 | TfR2 | TFR2 | Regulator of hepcidin |
Iron overload Human disease: hemochromatosis type 3 |
| Hemojuvelin | HJV | HFE2 | Regulator of hepcidin |
Severe iron overload Human disease: hemochromatosis type 2A |
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