Figure 3:

Experimental data, reproduced from [2]. EP2 and EP4 induce distinct cAMP responses. The intramolecular cAMP FRET sensor t-Epac-vv was used: binding of cAMP to t-Epac-vv reduces Förster Resonance Energy Transfer (FRET) between the mTurquoise donor and Venus acceptor fluorophores of t-Epac-vv, making a decreased ratio of the fluorescent intensities a direct measure of cAMP accumulation. (A) FRET ratios of t-Epac-vv before and after the addition of different PGE2 concentrations were measured in transiently transfected RAW macrophages. A control was performed with the addition of buffer only. The data presented are mean ± SD from ≥ 5 cells per condition. FRET ratios were measured after the addition of PGE2 in cells pretreated with EP2 antagonist (ant.) AH6809 (B), EP4 antagonist GW627368X (C), or pretreated with both GW627368X and AH6809 (D). The data presented are mean ± SD from ≥4 cells per condition.