Intestinal metal ion absorption: an update

Recent progress in the field of metal ion transport has significantly advanced our understanding of the mechanisms of intestinal metal ion absorption under normal and pathological conditions. In this brief review, we focus on the key proteins involved in intestinal absorption of iron, zinc, and copper. Following the initial description of the apical iron transporter, DCT1, the basolateral transporter complex has been identified, which consists of the metal transporter IREG1/MTP1 and the multicopper oxidase, hephaestin. Novel zinc and copper transporters have been identified as well, mostly based on their homology to yeast and plants transporters. The identification of a variety of copper and zinc transporters is consistent with the importance of copper and zinc in a wide variety of enzymatic reactions, free radical scavenging, and transcriptional control. Curr Opin Gastroenterol 2001, 17:177-183 (C) 2001 Lippincott Williams & Wilkins, Inc.