Fig. 4.

5-HT_2A receptor agonists are differentially responsive to RSK2 deletion. Concentration-response curves for IP accumulation in WT (■) and RSK2 KO (○) MEFs in response to 60-min treatment with 5-HT (A), 5-methoxy-DMT (B), m-CPP (C), lisuride (D), SCH-23390 (E), and α-Me-5-HT (F) show differential sensitivity to RSK2 expression. Relative efficacy values (E_max, 5-HT set to 100%) were determined via nonlinear regression and were significantly potentiated for all agonists in RSK2 KO MEFs, as shown in Table 1. Values represent the mean ± S.E.M. of four to five independent experiments performed in duplicate. E_max^RSK2KO/E_max^WT values were calculated for each agonist and are shown next to each plot as a measure of an agonist's propensity to signal in the absence of RSK2.