Figure 1.

Endogenous Gβγ subunits activate GIRK currents in G1,4 cells. Sample current traces show a large, inwardly rectifying current response to ramp hyperpolarizing voltage commands in G1,4 cells that was absent in HEK 293 cells. (Inset) Basal GIRK currents in G1,4 cells are inhibited by proteins that sequester Gβγ subunits. Conductance (i.e., the slope of I–V curve between −100 and −120 mV; mean ± SEM) was determined in HEK 293 cells (293), in G1,4 cells transfected with GFP alone (G1,4) and in G1,4 cells transfected with the indicated constructs. Note that Gα subunits of diverse families, as well as the C-terminal fragment of βARK, inhibited basal conductance in G1,4 cells. *, Significantly different from G1,4 (P < 0.05 by ANOVA with post hoc Dunnett's test).