Differential surface protein expression explains the divergent current amplitudes between WT and mutant KCNQ3.

<p>(A) Shown are representative fluorescent images from TIRF microscopy of CHO cells expressing YFP-tagged KCNQ3 WT or mutant channels. In all cases, CHO cells were transfected with a total of 2 μg cDNA. (B) Bars show summarized data for each channels (n = 57–63; ***p<0.001). (C) Shown are representative plasma membrane protein assays for the indicated channels. The upper panels show the plasma membrane myc-tagged protein; the middle panels show the cytosolic myc-tagged proteins and the lower panels show the total myc-tagged protein from whole-cell lysates. (D) Bars show summarized plasma membrane protein assays. For each experiment, the ratio of surface/total protein was calculated to estimate relative surface expression. These values were then compared with those of the indicated channels (n = 6; **p<0.01).