CHARACTERIZATION OF A PUTATIVE RECEPTOR FOR INTESTINAL TREFOIL FACTORIN RAT SMALL-INTESTINE - IDENTIFICATION BY IN-SITU BINDING AND LIGANDBLOTTING

Intestinal trefoil factor (ITF), a small peptide secreted by intestina l goblet cells, maintains mucosal integrity and promotes epithelial wo und healing. Although ITF has been cloned, the detailed mechanism by w hich ITF interacts with intestinal epithelium remains elusive. In the present study, we expressed mature rat ITF (rITF) with pXa (a prokaryo tic expression vector) in Escherichia coli to generate a biotinylated rITF fusion protein (bTag-ITF). By using bTag-ITF probe, we identified ITF binding cells in the crypts of the small intestine and mucous cel ls of the region of gastric glands. Using a ligand blotting technique, we further characterized a 50 kDa glycosylated protein from the membr ane fraction of the small intestine, which bound to bTag-ITF. Our data suggest that this 50 kDa membrane glycoprotein is a putative receptor for ITF in the gastrointestinal tract. (C) 1997 Academic Press.