FIG 12.

A short-tailed EGFR TM-ICM construct incorporated into vesicles does not exhibit biphasic autophosphorylation kinetics. (A) Negative-stained electron micrograph of vesicles reconstituted with EGFR TM-ICM truncated after residue 998 (left) and illustration of the location of phosphorylated tyrosines in this construct (right). The electron microscopy (EM) sample was prepared as for the samples shown in Fig. 11. (B) Time courses of autophosphorylation on the indicated tyrosines for the short-tail TM-ICM incorporated into vesicles, as quantified by Western blotting. Integrated band intensities for five replicate experiments (mean ± SEM) are plotted versus time and fit to a single exponential function. The time scale and reaction conditions are the same as in panel A. The reaction progress curves fit well to a single exponential decay, unlike the full-length tail constructs shown in Fig. 11.