Figure 5.

Dissociation between organelles containing ¹²⁵I-ON and lysosomes in sucrose gradients after pulse-chase. HepG2 cells were incubated at 37°C for 2 h with 250 nM ¹²⁵I-ON combined with 100 µM HRP in serum-free medium as in Figure 4, followed by a 22 h chase in the presence of serum. During the last 4 h, 100 µM chloroquine was added (thick line) or not (thin line), prior to washing and pronase digestion. Distributions of ¹²⁵I-ON (A), cathepsin B (B) and HRP activities (C) are compared in the same cells and presented as in Figure 4. Recoveries ranged between 82 and 123%. Data are from a representative experiment out of three. Arrowheads represent median densities in the absence (open symbols) and presence (filled symbols) of chloroquine.