Fig. 6. Dominant negative effect of UIM^-WT on c-Cbl-mediated EGFR internalization depends on intact UIM. CHO cells expressing the EGFR alone () or co-expressing the EGFR and FLAG-tagged UIM-WT (A) or UIM-mut (B) constructs (see Fig. 5A) in the presence () or absence of c-Cbl () were incubated at 37°C with 1 ng/ml ¹²⁵I-labelled EGF. Internalization was determined as outlined in Materials and Methods. Presented is the ratio of internalized to total-cell-associated radioactivity. The experiments contained triplicate samples. Error bars represent standard deviations.