Fig. 4.

Expression of dimeric constructs containing wild-type GIRK1, GIRK2, or GIRK3 subunits linked to GIRK2wv (wv) leads to functional channel expression. The presence of GIRK1 in functional channels determined channel selectivity and G-protein dependence. Currents were recorded as in Figure 1. A, B, TheI–V relationships for recombinant channel currents determined 92 msec after the initiation of the voltage pulse for 8–22 oocytes pooled from three batches for each experimental condition.C, Summary of mean current amplitude of the basal- and carbachol-induced currents measured at −150 mV in oocytes expressing indicated dimers.