Fig. 4. c-Cbl and the activated EGFR colocalize at the plasma membrane of permeabilized COS cells. COS-7 cells transfected with c-cbl cDNA were plated on coverslips, serum starved and stimulated with 25 ng ml^-1 EGF for the indicated time periods at 37°C (A-I) or on ice (J-L). Prior to fixation, cells were permeabilized with saponin. Cells were stained with mAb directed against the EGFR followed by FITC-conjugated secondary antibody (green; A,D,G,J) and with polyclonal antibody directed against c-Cbl followed by Texas-Red-conjugated secondary antibody (red; B,E,H,K) and analysed by confocal microscopy. Merged images are shown in C, F, I and L. The confocal image in panels A-C was taken at the level of the basal membrane, that in panels G-I at the middle of the cell. The insert in L shows a xz section.