Figure 1

β2AR phosphorylation in HEK293 cells challenged with beta-adrenergic agonist. HEK293 clones stably expressing N-terminal Flag-tagged, C-terminal eGFP-tagged β2AR were treated either with 100 nM isoproterenol for the indicated times (A) or with varying concentrations of the beta-adrenergic agonist, isoproterenol for 5 min (B). β2AR was immunoprecipitated with anti-Flag immunoadsorption beads. SDS-PAGE and immunoblotting were performed as indicated in the Materials and methods section. The phosphorylation of β2AR was normalized to total β2AR. The data were quantified and are displayed as percentage of maximum phosphorylation of each site (s). The experimental data shown is of a single analysis performed in triplicate and replicated multiple times with similar results.