FIGURE 4.

MDR3 mutation Q1174E does not affect protein localization in vivo or in vitro. A, sample from a liver with normal MDR3 expression (upper panel) and from the patient carrying the heterozygous Q1174E mutation (lower panel). The green fluorescence corresponds to bile salt export pump (BSEP), which acts as a canalicular marker, and the red fluorescence represents MDR3. B, transient expression of human wild type (upper panel) and Q1174E (lower panel) MDR3-eYFP (green) after transfection into HEK293 cells. Cells were fixed after 48 h and stained for the Na⁺/K⁺-ATPase as a plasma membrane marker (red). Scale bars, 20 μm.