FIGURE 4.
Influence of GHS-R1a dimerization on G protein activation. A, BODIPY FL GTPγS binding to Gαq (Gαqβ1γ2) induced by GHS-R1a-containing discs in the presence of an increasing concentration in ghrelin. Data are presented as the percentage of maximum BODIPY FL fluorescence change measured in the presence of ghrelin. B, BODIPY FL GTPγS binding to Gαq triggered by the purified receptors in the absence and in the presence of ligands (full agonist, ghrelin; partial agonist, JMV3002; neutral antagonist, JMV3011; inverse agonist, SPA; ligand concentration, 10 μm). 1a, GHS-R1a monomer; 1b, GHS-R1b monomer; 1a:1a, GHS-R1a-GHS-R1a homodimer; 1a:1b, GHS-R1a-GHS-R1b dimer. In all cases, the data represent the mean ± S.D. from three independent experiments.