Fig. 6. Internalized HDLp is trapped intracellularly by monensin. CHO(iLR) cells were incubated with fluorescently-labeled ligands in the presence of 25 µM monensin for 30 minutes at 18°C. The cells were subsequently chased for 30 minutes at 37°C with an equal concentration of monensin and mounted in mowiol after fixation. LDL was scattered throughout the cell in vesicles (A); however, HDLp was predominantly located in the juxtanuclear area (B). The non-exchangeable protein matrix of HDLp is transported to the ERC. CHO(iLR) cells were allowed to take up OG-HDLp for 15 minutes at 37°C in the presence of 25 µM monensin. After a chase of 30 minutes with an equal concentration of monensin, the cells were washed and labeled with antibodies against apoLp-I and -II, which were visualized with a Cy5-labeled second antibody. The fluorescent label OG that represents intracellular HDLp (C,D) colocalized with apoLp-I (E) and -II (F) in the juxtanuclear area (G,H). Bars, 10 µm.