FIGURE 1.
Functional expression of CLR co-transformed with all three RAMPs in yeast cells. Dose-response curves to CGRP, AM, and AM2 were constructed in yeast strains containing the GPA1/Gαs chimera and expressing CLR with RAMP1 (n = 6) (A), RAMP2 (n = 7) (B), and RAMP3 (n = 8) (C). Reporter gene activity was determined following 20 h of stimulation with each ligand. Data are expressed as a percentage of the maximum response observed in yeast strain MMY11 (lacking GPA1) and are means ± S.E. of n individual data sets. D, bar chart showing the efficacy of each ligand for each RAMP-CLR combination as determined via application of the operational model of receptor agonism (see Ref. 34 and Table 1). Data were determined as statistically different from the cognate ligand for each receptor (*, p < 0.05; **, p < 0.01; ***, p < 0.001) using a one-way ANOVA with Bonferroni's post-test.