FIGURE 3.

PEPT2 is expressed by human phagocytic cells. a, ClustalW analysis of Drosophila Yin and the related human SLC15 oligopepetide transporters, PEPT1, PEPT2, SLC15A3, and SLC15A4. Yin shares 33–35% with identity PEPT1/2 but only 17% with SLC15A3/A4. PEPT1 and PEPT2 are 50% identical. Expression of the SLC15 family members in kidneys, THP1 (human monocyte/macrophage cell line), peripheral blood monocytes, Caco2, (colonic epithelial cell line), and HEK293T (human kidney epithelial cell line) was determined by 40 cycle RT-PCR (b) and quantitative RT-PCR (c). PEPT2, but not PEPT1, is expressed by human phagocytes, which also express SLC15A3 and SLC15A4. RLU, relative light units.