Figure 4. AII binding to the receptors is required for concomitant internalization.

(a) HeLa cells prepared as described in Fig. 3c were pretreated with either losartan or PD123319. The cells were observed by fluorescence microscopy and then exposed to AII. (b) The cells prepared as in (a) were subjected to time-lapse microscopy. The time course of FRET^C in each sample was plotted. Error bars indicate the s.e.m. (n = 3).