Fig. 2.

Survival of 293T cells transfected with WT and mutant KCNJ5 channels. WT or mutant eGFP-tagged KCNJ5 was transfected into 293T cells, and the percentage of eGFP-positive cells was measured at indicated times by flow cytometry (20,000 events counted per data point). (A) Incubation in physiologic medium (Materials and Methods) shows lower percentage of cells expressing KCNJ5^G151R than KCNJ5^WT at 36 h (P = 0.003) and lower percentage of cells expressing KCNJ5^G151E than either KCNJ5^WT (P < 0.0001) or KCNJ5^G151R (P = 0.003). (B) Reduction of extracellular Na⁺ by choline substitution significantly increased survival of cells expressing KCNJ5^G151R and KCNJ5^G151E at 24 and 36 h, with a more pronounced effect on the G151E mutant (for both mutant channels, P = 0.02 for low Na⁺ vs. normal medium at 24 h; P = 0.04 at 36 h).