Figure 2. Isoproterenol-induced changes in BRET are sensitive to inhibitors of clathrin-mediated endocytosis.

A–E, the percent change in net BRET induced by isoproterenol is plotted for cells expressing β₂AR-Rluc8 and V-kras (left) or β₂AR-Rluc8 and β₂AR D113S-V (right). Cells were pretreated with vehicle or were cotransfected with vector (control), or were pretreated with 400 mM sucrose (A; n = 5 and 5), incubated at 4°C (B; n = 5 and 6), cotransfected with arrestin2 (319–418) (C; n = 6 and 6), cotransfected with dynamin K44A (D; n = 5 and 5), or pretreated with dynasore (80 µM; E; n = 4 and 4); **, P<0.005, paired t-test, meaning the percent change in net BRET in the presence of sucrose, etc., is significantly different from the control percent change in net BRET. Values of net BRET are given in Table S2 and Table S4.