The functional evaluation of human peptide/histidine transporter 1 (hPHT1) in transiently transfected COS-7 cells.

Recently, the expression of the human peptide/histidine transporter (hPHT1, SLC15A4) mRNA was observed in the GI tract and in Caco-2 cells, suggesting that it may participate in the intestinal absorption of peptide-based agents. This study aims to elucidate the: (i) protein expression pattern of hPHT1 (SLC15A4) in human small intestine; (ii) cloning of the hPHT1 full-length sequence; (iii) functional characterization of hPHT1 in transiently transfected COS-7 cells. The expression of hPHT1 was measured using Western blot and immunohistochemical analysis.