KCNE1 Antibody - #DF6310

Figure 2. KCNQ1 P441L variant protein trafficking in the absence or presence of KCNE1 (potassium voltage-gated channel subfamily E regulatory subunit 1), and the interaction between the KCNQ1 P441L variant and KCNE1 proteins. (A–C) Representative confocal microscopy images and line plots showing the cellular distribution of wild-type and P441L variant KCNQ1 proteins in HEK293 cells. Scale bar, 10 μm. KCNQ1 was tagged with EGFP at the N-terminus and thus is shown as green fluorescence. Red fluorescence indicates the endoplasmic reticulum (ER); blue fluorescence, 4′,6-diamidino-2-phenylindole (DAPI), indicates cell nuclei. Line plots in panel (C) represent profiles plotted from left to right (L–R) to display the relative red and green fluorescence intensities obtained at the orange lines shown in the merged images. (D) Representative Western blot images showing fractionation assay results indicating that compared with the wild-type KCNQ1-EGFP (WT) protein level, the P441L-EGFP (P441L) protein level is significantly lower in the cell membrane but significantly increased in the cytoplasm. (E–G) Representative confocal microscopy images and line plots showing the cellular distribution of WT and P441L variant KCNQ1 proteins in HEK293 cells in the presence of KCNE1. Scale bar, 10 μm. HEK293 cells were transfected with KCNQ1-EGFP/KCNE1-mCherry (E), or P441L-EGFP/KCNE1-mCherry (F). Green fluorescence indicates KCNQ1; red fluorescence indicates KCNE1; and blue fluorescence, 4′,6-diamidino-2-phenylindole (DAPI), indicates cell nuclei. Line plots in panel (G) represent profiles plotted from left to right (L-R) to display the relative red and green fluorescence intensities obtained at the orange lines shown in the merged images. (H) Representative Western blot images showing fractionation assay results indicating that only a small amount of expressed P441L-EGFP protein is detected on the cell membrane when P441L-EGFP/KCNE1-mCherry are co-transfected into HEK293 cells. (I) Representative co-immunoprecipitation (IP) images showing KCNQ1 and KCNE1 proteins in lysates of HEK293 cells. In KCNQ1-EGFP/KCNE1-mCherry (WT) or P441L-EGFP/KCNE1-mCherry (MUT) expressed in HEK293 cells, the products of the IP showing KCNE1 pulled down by WT KCNQ1 or by the P441L variant. (J) Summary data showing the ratio of KCNE1 to WT KCNQ1 or the P441L variant pulled down IP products. WT represents KCNE1/KCNQ1; MUT, KCNE1/P441L variant. Data are shown as the mean ± SEM, n = 4, *P < 0.05, WT vs. MUT.