Figure 5.

Analysis of the simultaneously recorded receptor/G protein interaction and GIRK currents. (A) In cells expressing α_2A-YFP, Gαi₁β₁ CFP-γ₂ and GIRK1+4, FRET responses (thick curves) and GIRK currents (thin curves) were measured simultaneously after stimulation with 100 μM NE (bar; complete reversal of GIRK currents not shown). (B) FRET responses (thick curves) and GIRK currents (thin curves) were recorded during two subsequent stimulations with 1 and 100 μM NE (gray and black curves, respectively) in the same cell. The amplitudes obtained with the 100 μM NE were set to 100%, and the FRET and GIRK current traces following 1 μM NE stimulation were normalized accordingly (n=6, representative recording shown).