Figure 1.

Effect of mβCD and mβCD/chol on endocytosis of transferrin (A) and ricin in the absence (B) and presence of monensin (5 μM) (C). The HeLa-TetOn/Rab9S21N cells were washed twice in HEPES medium and incubated with or without 5 mM mβCD and mβCD/chol for 30 min at 37°C before ¹²⁵I-labeled transferrin or ¹²⁵I-labeled ricin were added to the cells. The amounts of endocytosed transferrin was measured after 5 min, while the amounts of endocytosed ricin was measured after 15 min and 2 h as described in Material and Methods. The error bars show deviations between duplicates of a typical experiment.