Role of Transferrin in Iron Metabolism

Transferrin plays a vital role in iron metabolism. Transferrin is a glycoprotein and has a molecular weight of ~80 kDa. It contains two homologous iron-binding domains, each of which binds one Fe (III). Transferrin delivers the iron to various cells after binding to the transferrin receptor on the cell surface. The transferrin-transferrin receptor complex is then transported into the cell by receptor-mediated endocytosis. The iron is released from transferrin at low pH (e.g., endosomal pH). The transferrin-transferrin receptor complex will then be transported back to the cell surface, ready for another round of Fe uptake and release. Thus, transferrin plays a vital role in iron homeostasis and in iron-related diseases such as anemia. In the case of anemia, an increased level of plasma transferrin is often observed. On the other hand, low plasma transferrin level or transferrin malfunction is observed during the iron overdose. This chapter will focus on the role of transferrin in iron metabolism and diseases related to transferrin