Which membrane-associated protein in enterocytes is responsible for transporting iron from the intestinal lumen into the cell?

DMT1, or Divalent Metal Transporter 1, is the specific membrane-associated protein in enterocytes that facilitates the transport of iron from the intestinal lumen into the cell. This protein actively transports ferrous iron (Fe²⁺) across the apical membrane of intestinal epithelial cells, a critical step for iron absorption.

Once inside the enterocyte, iron can be stored or released into the bloodstream as needed. DMT1 is essential for maintaining iron homeostasis in the body and plays a significant role in the gut's ability to absorb dietary iron effectively.

Transferrin, while vital for iron transport in the bloodstream, binds to iron only after it has been taken up by enterocytes and is not involved in initial iron absorption from the lumen. Ferroportin is a cellular protein responsible for exporting iron from the enterocyte into circulation, but it does not function at the apical membrane for iron uptake. Ferrochelatase is an enzyme involved in heme synthesis and does not play a direct role in iron transport across cell membranes.