Transport Mechanism
When a transferrin protein loaded with iron encounters a transferrin receptor on the surface of a cell (e.g., to erythroid precursors in the bone marrow), it binds to it and, as a consequence, is transported into the cell in a vesicle by receptor-mediated endocytosis. The pH of the vesicle is reduced by hydrogen ion pumps (H+ ATPases) to about 5.5, causing transferrin to release its iron ions. The receptor (with its ligand, transferrin, bound) is then transported through the endocytic cycle back to the cell surface, ready for another round of iron uptake. Each transferrin molecule has the ability to carry two iron ions in the ferric form (Fe3+).
The gene coding for transferrin in humans is located in chromosome band 3q21. Research on kingsnakes by Dessauer and Zwiefel in 1981 revealed that the inheritance of transferrin is a codominant trait.
Medical professionals may check serum transferrin level in iron deficiency, hemochromatosis, and other iron overload disorders.
Read more about this topic: Transferrin
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