Figure 3.

Plasma membrane proteins on endosomes. Detection of various plasma membrane-associated proteins in purified endocytic vesicles and lysosomes. For rab 4, rab 5a and transferrin receptor (Trf-R) lanes contained 100 μg, 100 μg and 30 μg protein, respectively and blots shown are representative of studies of 6–10, 6–10 or 2 different preparations of each cell fraction, respectively. For MRP-2 and MDR-1, lanes contained 100 μg of protein except for CM (10 μg and 5 μg, respectively) and BLM (10 μg) and blots shown are representative of studies of 4–12 and 17–19, respectively, different preparations of each cell fraction.