Current data on iron metabolism

Iron is required for cellular life. However, abnormalities of its metabolis m may lead to iron deficiency or iron overload both conditions which are de leterious. Therefore, stock and distribution of iron in the body must be ve ry stable. Classically, four major proteins are involved in iron metabolism : (a) transferrin which is implicated in its plasmatic transport, (b) tran sferrin receptor which regulates iron-transferrin uptake, (c) ferritin, the major iron storage protein, and (d) IRP (Iron Regulatory Protein) which re gulates both the entry and storage of iron by linking to the IRE (Iron Resp onsive Element), a nucleotidic sequence found on transferrin receptor and f erritin mRNA. Thus, IRP adapts gene expression to the iron cellular status. Recent data give informations about new proteins involved in iron metaboli sm: HFE whose gene is mutated in genetic hemochromatosis, ceruloplasmin whi ch permits cellular iron egress and frataxin which is implicated in the exi t of iron from mitochondria.