Transferrin receptor

Function

Transferrin receptor (TfR) imports iron into the cell by receptor-mediated endocytosis of transferrin-iron complex. TfR is regulated by intracellular iron concentration. The amount of TfR expressed on the cell is proportional to the cell’s need for iron. The TfR has selective affinity for diferric-transferrin. The TfR-transferrin complex is internalized by the cell and iron is released to the cytosol. The TfR-apotransferrin complex returns to the extracellular surface where the apotransferrin dissociates and is replaced by diferric-transferrin^[1].

Relevance

TfR is a potential determinant of iron loading in congenital anemias^[2].

Structural highlights

• (1suv).

3D structures of transferrin receptor

1cx8 – hTfR ectodomain – human
1de4 - hTfR ectodomain + hemochromatosis protein + β-2-microglobulin
1suv - hTfR ectodomain + transferrin
3s9l, 3s9m, 3s9n - hTfR ectodomain + transferrin N-lobe
2nsu - hTfR ectodomain in dog retrovirus – Cryo EM
3kas - hTfR ectodomain + Machupo virus GP1

References

1. ↑ Levy JE, Jin O, Fujiwara Y, Kuo F, Andrews NC. Transferrin receptor is necessary for development of erythrocytes and the nervous system. Nat Genet. 1999 Apr;21(4):396-9. PMID:10192390 doi:http://dx.doi.org/10.1038/7727
2. ↑ Cazzola M, Beguin Y, Bergamaschi G, Guarnone R, Cerani P, Barella S, Cao A, Galanello R. Soluble transferrin receptor as a potential determinant of iron loading in congenital anaemias due to ineffective erythropoiesis. Br J Haematol. 1999 Sep;106(3):752-5. PMID:10468869