6d05

Structural highlights

Disease

[TRFE_HUMAN] Defects in TF are the cause of atransferrinemia (ATRAF) [MIM:209300]. Atransferrinemia is rare autosomal recessive disorder characterized by iron overload and hypochromic anemia.^{[1] [2]}

Function

[TFR1_HUMAN] 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). A second ligand, the heditary hemochromatosis protein HFE, competes for binding with transferrin for an overlapping C-terminal binding site.^[3] [TRFE_HUMAN] Transferrins are iron binding transport proteins which can bind two Fe(3+) ions in association with the binding of an anion, usually bicarbonate. It is responsible for the transport of iron from sites of absorption and heme degradation to those of storage and utilization. Serum transferrin may also have a further role in stimulating cell proliferation.

References

1. ↑ Beutler E, Gelbart T, Lee P, Trevino R, Fernandez MA, Fairbanks VF. Molecular characterization of a case of atransferrinemia. Blood. 2000 Dec 15;96(13):4071-4. PMID:11110675
2. ↑ Knisely AS, Gelbart T, Beutler E. Molecular characterization of a third case of human atransferrinemia. Blood. 2004 Oct 15;104(8):2607. PMID:15466165 doi:10.1182/blood-2004-05-1751
3. ↑ Rothenberger S, Iacopetta BJ, Kuhn LC. Endocytosis of the transferrin receptor requires the cytoplasmic domain but not its phosphorylation site. Cell. 1987 May 8;49(3):423-31. PMID:3568132