Figure 1. Real-time FRET determinations of antiparkinsonian D₂R agonist-mediated modulation of A_2AR agonist binding.

(A) Chemical structures of the investigated antiparkinsonian D₂R agonists (pramipexole, rotigotine and apomorphine). (B) Time-resolved changes in FRET signals engaged by MRS5424 (2 µM) in cells transfected with A_2AR^CFP and D₂R^AGT in the absence (black trace) or presence (red trace) of pramipexole (120 µM), rotigotine (1 µM) and apomorphine (6 µM) were recorded. Traces are representative of four separate experiments with similar qualitative and quantitative results. (C) The FRET increase (1/F₄₈₀) was fitted by a simple monoexponential curve and the magnitude of the FRET signal (A, see experimental procedures) calculated for each experimental condition. Data represents the average ± S.E.M. values of four independent experiments. Asterisk indicates data significantly different from the control condition (i.e. in the absence of antiparkinsonian D₂R agonist): *p < 0.01 by ANOVA with Dunnett`s multiple comparison post-hoc test.