The Del α
-AR displays impaired agonist-promoted phosphorylation in PC12 cells. A. Transfected PC12 cells were exposed to 10 μΜ UK 14304 for 10 min and then immunoprecipitation (IP) of the α2B-ARs was performed, followed by immunoblotting (IB) to measure their phosphoserine (P-Ser) content. Equal amounts of receptor were loaded on each lane, as determined from ligand binding data and protein determination by the Bradford method. Shown is a representative blot from five independent experiments. B. Densitometric analysis of the immunoblots of Panel A, showing agonist-induced receptor phosphorylation as fold increase of the basal phosphorylation of WT α2B-AR. *, p < 0.05, vs. all other conditions, n = 5.