Figure 8.

E3-13.7 enriched in early endosomes coimmunoprecipitates with the EGF receptor. Postnuclear supernatants from adenovirus-infected ERwt cells that had been metabolically labeled from 15 to 18 h after infection were fractionated on 27% Percoll gradients. Fraction 2 membranes enriched for E3-13.7 and the EGF receptor were solubilized with RIPA or CHAPS detergent, and lysates were immunoprecipitated with the use of antibodies to the proteins listed at the top of the figure. One-half of each immunoprecipitate was resolved on a 7.5% (top panels), and the other on a 15% (bottom panels), polyacrylamide gel for detection by fluorography. Note that autoradiograms of EGF receptor immunoprecipitates were exposed for 2 d, compared with 14 d for E3-13.7 immunoprecipitates.