Decreased Kv2.1 V378A expression and lack of rescue by GxTX in CHO-K1 cells. (A) Multiplex imaging of EGFP (green), Kv2.1 (red), and Hoechst 33258 (blue, to label nuclei), indicating reduced incidence of Kv2.1 V378A expression compared with wild-type Kv2.1. Bar, 10 µm. (B) Similar transfection efficiency of EGFP but significantly lower transfection efficiency of Kv2.1 V378A compared with wild-type Kv2.1, as measured by immunofluorescence labeling (n = 3 independent samples per treatment). (C) Immunoblot analysis of CHO-K1 cell extracts cultured in the absence or presence of 400 nM GxTX, showing reduced levels of V378A Kv2.1 protein that is not rescued by 400 nM GxTX treatment. Actin was used as a loading control. (D) Quantitation of immunoblot analyses demonstrating significantly lower expression and lack of GxTX rescue in Kv2.1 V378A-expressing cells relative to wild type (n = 3 per treatment). **, P < 0.01, by two-way ANOVA followed by post-hoc Tukey tests. Error bars represent means ± SEM.