Localization of the iron transport proteins Mobilferrin and DMT-1 in the duodenum: The surprising role of mucin

摘要: There are two pathways for inorganic iron uptake in the intestine, ferric pathway, mediated by key protein mobilferrin, and ferrous DMT-1. Previous studies reported that amount of DMT-1 increased intestinal mucosa deficiency increase was seen apical portion villus duodenal mucosa. Mobilferrin did not quantitatively but became localized at cell membrane. However, on fresh tissue have previously been performed localization to microvillae has demonstrated. In order more definitively localize these proteins immunofluorescent electron microscopic were undertaken. Samples also subjected biochemical analysis Western analysis. iron-deficient animals both concentrated surface villae. Electron microscopy revealed majority this near luminal due binding mucin vesicles surface. A significant transport goblet cells outside mucin, as demonstrated immunofluorescence, microscopy, isolation cesium chloride gradient centrifugation new model metal ions suggested. The travel from inside out lumen mucin. This increases area allows a greater contents be exposed proteins. Once is bound externalized it internalized into cell. explains many unique properties iron-binding suggests may general absorption other nutrients. Am. J. Hematol. 74:32–45, 2003. © 2003 Wiley-Liss, Inc.