Another jigsaw piece towards solving the iron metabolism puzzle:the cloning of the iron exporter, ferroportin1

Abstract

Over the last 4 years, a flurry of genetic studies have brought about revolutions in our understanding of the molecular processes involved in iron (Fe) metabolism. In 1996, Feder and colleagues discovered that the gene HFE is mutated in the Fe-overload disease hemochromatosis.¹ During 1997, two groups discovered that a previously cloned gene (Nramp2) encoded an Fe transporter involved in Fe uptake.^2–4 This molecule has been called the divalent metal transporter 1 (DMT1), and is involved in the uptake of Fe across the apical enterocyte membrane and also Fe transport across the endosomal membrane after its release from transferrin (Tf).^2–4 After a brief hiatus in 1998, another gene, known as hephaestin, was found in 1999 that plays some role in Fe transport in the intestinal enterocyte.⁵ In the latest discovery, Donovan and colleagues have positionally cloned a gene called ferroportin1 that encodes a membrane-spanning molecule which could be involved in the export of Fe from cells.⁶ These discoveries have provided the jigsaw pieces of a puzzle that still remains to be completely solved.