Figure S2. Characterization of stably transfected MDCK-MRP2 cells and the MRP2 inside-out vesicles. (A) Immunoblot of MRP2 in MDCK-MRP2 and vector transfected MDCK2-cells (VC) cells. At the molecular mass of approximately 190 kDa, specific signals were detected in MDCK-MRP2 cells, which were not detectable in MDCK-VC cells. (B) Immunofluorescence analysis of MDCK-MRP2 and MDCK-VC cells using immunofluorescence microscopy. MRP2 was localized in the apical plasma membrane of the MDCK-MRP2 cells, whereas no staining was detectable in the MDCK-VC cells, scale bar = 20µm (C) Uptake of E2-17ß-Gln (mean±SD) and (D) competition of MK571 (0-100 µmol/l) with the uptake of E2-17ß-Gln into MRP2 inside-out vesicles.