Figure 1

Wg internalizes by clathrin- and dynamin-mediated endocytosis, and localizes to transferrin recycling compartments. Immunostaining for Wg was performed in L cells incubated in the absence (a) or presence of Wg (b-l, n-s). Cells were incubated with Wg at 37°C (b) or 4°C (c), and in the presence of MDC (d), hypertonic sucrose (e), or CPZ (f). Internalized Wg was assessed by immunostaining. L cells transfected with GFP alone (g and j are identical fields; transfected cells indicated by arrows and non-transfected cells indicated by arrow-heads), or in combination with either wild-type dynamin (h and k are identical fields; transfected cells indicated by arrows and non-transfected cells indicated by arrow-heads) or K44E-mutated dynamin (i and l are identical fields; transfected cells indicated by arrows) were assessed for Wg endocytosis by immunostaining. (m) Quantitation of results in (g-l) where values represent means ± SEM from 3 independent determinations.