Figure 4: Impairment of EGFR internalization phenocopies PHD3 loss.

(a,b) Dynasore inhibits EGFR internalization. G55 cells were treated for 2 h with DMSO control or dynasore (0.32 mM), an inhibitor of dynamin-dependent endocytosis. EGFR co-localizes at early time points with EEA1, peaking at 15 min after stimulation. Dynasore compromises EGFR internalization, with EGFR remaining at the plasma membrane (a). Quantification of the increase in EGFR/EEA1 co-localization relative to non-stimulated cells (n=50–200) is shown in b. (c) Impairment of EGFR internalization increases EGFR phosphorylation. Immunoblot of G55 cells non-stimulated or stimulated with 20 ng ml⁻¹ EGF and treated with control DMSO or dynasore. Western blot images (c) have been cropped for presentation. Full-size images are presented in Supplementary Fig. 6. All values are means+s.e.m., Student’s t-test *P<0.05. Scale bar, 10 μm.