Figure 3

Histogram and photomicrographs illustrating relative FRET efficiencies and FACS analysis in HEK-293 cells cotransfected with hSSTR5 and β ₂ AR. (A) Activation of hSSTR5 with SST or β₂AR with formoterol displayed decrease in the FRET efficiency indicating the dissociation of receptor complex upon activation of individual receptors. In contrast, upon combined treatment with SST (1 μM) and formoterol (1 μM), cells displayed enhanced heterodimerization. Mean ± S.E. are representative of three independent experiments performed in duplicate. Data analysis was done by using ANOVA and post hoc Bonferroni's Multiple Comparison test to compare with control and treated conditions. (B-D) Approximately 2 × 10⁶ cells were treated with receptor specific agonist as indicated in materials and methods section. Cells were washed with FACS buffer, fixed in 4% paraformaldehyde and were processed for immunostaining as described. BD LSRII flow cytometer, configured with a 488 nm and 561 nm laser was used for the experiments. Cy3 labeled cells were used as control (Panel B). Note the increased emission in 610/20 channel when cells were excited with 488 nm laser in control (Panel C) as well as upon combined agonist treatment (Panel D).