Fig. 5. Electron microscopy of structures containing myc-tagged wild-type Hrs (A) and Hrs^C215S (B). Transfected BHK cells were incubated in the presence of 3-7-nm BSA-gold for 10 minutes at 37°C prior to fixation and immunostaining for anti-myc (15-nm gold). Endocytosed BSA-gold is visible in the two myc-Hrs-positive structures (A). The arrow in (B) indicates a small endocytic profile that contains encocytosed BSA-gold, whereas the Hrs^C215S-containing structure is negative. n, nucleus; m, mitochondrion. Bars, 200 nm.