Fig. 1

Effect of interference peptides on the A₁-A_2AHet structure determined by bimolecular fluorescence complementation (BiFC) assays. a–e BiFC assays were performed in HEK-293 T cells transfected with cDNAs (1 μg) for A_2AR-nYFP, A_2AR-cYFP, and non-fused A₁R (a) or A_2AR-cYFP and A₁R-nYFP (b–e). Cells were pre-treated for 4 h with medium (control, broken lines) or with 4 μM of A_2AR TM synthetic peptides (TM1 to TM7, green squares) or A₁R synthetic peptides (TM5 to TM7, orange squares). Subsequently, they were left untreated (a, b) or activated for 10 min with the A₁R agonist CPA (c, 100 nM), the A_2AR agonist CGS-21680 (d, 100 nM), or both (e). Fluorescence was read at 530 nm. Mean ± SEM (13 experiments/treatment). One-way ANOVA followed by a Dunnett’s multiple comparison test showed a significant fluorescence decrease over control values (*P < 0.05, **P < 0.01, ***P < 0.001). In each panel, there is a schematic representation of the BiFC pairs and conditions. (f) Schematic slice (left) and cartoon (right) representations of the A₁-A_2AHet built using the predicted experimental interfaces