Figure 5.

HeLa^K44A cells internalize uPA:PAI-1 through a clathrin-independent pathway. HeLa^K44A cells were incubated for 5 min at 37°C in the presence of iodinated holo-transferrin (black bars), ricin (white bars), or uPA:PAI-1 (hatched bars) and surface-associated and internal counts per minute were subsequently determined as described in MATERIALS AND METHODS. Results are expressed as internalization index (internalized counts per minute/total cell-associated counts per minute) and normalized relative to control HeLa cells expressing wild-type dynamin. Mean and SD of three independent experiments in duplicate are shown.