Fig. 1: MRAP2 co-expression enhances cAMP signaling.
From: MRAP2 modifies the signaling and oligomerization state of the melanocortin-4 receptor
A Average concentration-response curves of cAMP response upon MC4R stimulation with α-MSH, with and without different amounts of MRAP2 in transiently transfected HEK293 cells using the EpacSH187 biosensor. Data are normalized to forskolin response in the presence of the phosphodiesterase inhibitor IBMX (100%). MC4R is first expressed with an equivalent amount of pcDNA (mock). Plasmid DNA coding for MRAP2 is then co-expressed either in equivalent amounts (1 + 1) or with a fourfold higher molar concentration with respect to the MC4R (1 + 4), always maintaining constant the total amount of DNA transfected. Mean and standard error of the mean (± SEM) of six independent experiments (with three technical replicates each) are shown. B pEC50 values obtained using the Epac-SH187 FRET biosensor. Results are represented in a bar chart as mean ± SEM, in which individual pEC50 data point from the six individual experiments are shown as overlaid dot plot. One-way ANOVA as statistical test was performed with Tukey’s multiple comparisons post-hoc test (**: adjusted p-value = 0.0018, ***: adjusted p-value = 0.0005). C Basal cAMP values (as assessed by FRET ratio) in the presence or absence of MRAP2 measured using the Epac-SH187 FRET biosensor in cells transfected different amounts of MRAP2 relative to the MC4R. Results are represented in a bar chart as mean ± SEM, in which individual data point from the six individual experiments are shown as overlaid dot plot. One-way ANOVA as statistical test was performed with Dunnett’s multiple comparisons post-hoc test (**: adjusted p-value = 0.0014, ****: adjusted p-value < 0.0001).
