Figure 1.
The A1 adenosine receptor couples to Kir3.1+3.2A channels via Giα1–3 and GoαA. (A) This illustrates the experimental protocol used. The HKIR3.1/3.2/A1 monoclonal cell line stably expressing Kir3.1+3.2A channels together with the A1 receptor was transiently transfected with mutant PTx-insensitive Gi/oα subunits, and then cells were treated with PTx 1 day before electrophysiological recording. (B) These are examples of traces showing the effects of stimulating A1 receptors in the HKIR3.1/3.2/A1 cell line in PTx-treated cells (top traces) and when each of the mutated Gi/oα variants was co-expressed. Currents were elicited by holding cells at 0 mV and stepping to potentials between −100 and +50 mV in 10-mV increments for 100 ms. Traces indicate current responses before (Basal), during (+ NECA), and after (Wash) receptor stimulation.