FIGURE 9.

ICL3-9 antagonizes β-agonist promoted β₂AR desensitization processes. A, 100 nm isoproterenol-induced β₂AR internalization was monitored by cell surface ELISA in HEK 293 cells stably overexpressing a FLAG-β₂AR that were pretreated with various concentrations of ICL3-9 for 5 min (0.05% DMSO was included in non-pepducin-treated cells). The data are represented by the mean of three independent experiments ± S.D. B, HEK 293 cells co-transfected with GFP10-β-arrestin2 and β₂AR-RLucII (same pair as in Fig. 2B) were preincubated with coelenterazine 400a and various concentrations of ICL3-9 for 2 min and stimulated with 100 nm isoproterenol. BRET was monitored at the indicated times post-addition. Background BRET has been subtracted from the plotted points. The data are represented by the mean of four independent experiments ± S.D.