Figure 3.

Localization of NHE6.1 in SAC. HepG2 cells stably expressing NHE6.1-mCherry (red) were labeled with 4 μM C₆-NBD-GlcCer or C₆-NBD-SM (green) at 37°C for 30 min. Subsequently, fluorescent lipid analogue remaining in the basolateral membrane was removed by back exchange method with 5% BSA on ice. Cells were further incubated at 18°C for 60 min to induce accumulation of the lipid analogue at SAC. To selectively quench the fluorescence at BC, cells were incubated with 30 mM sodiumdithionite at 4°C for 7 min [sodium dithionite (+)]. As a control, cells were treated with HBSS at the same condition [sodium dithionite (−)]. Cells were directly subjected to observation by microscope under live condition. Merged fluorescent images and phase contrast images are also shown (Merged and PC, respectively).