The A343D mutation abolishes axonal expression of HA-KCNQ3/KCNQ2 channels.

<p>(A) Permeabilized immunostaining was performed to visualize total (surface and intracellular) expression of HA-KCNQ3/KCNQ2 WT or mutant (A343D and R353G) channels (inverted images, upper). The axon was identified by the AIS marker phospho IκBα Ser32 (14D4) whereas neuronal soma and dendrites were visualized by MAP2 immunostaining (lower). The A343D but not the R353G mutation abolished total expression of HA-KCNQ3/KCNQ2 channels at the axon. Arrows indicate the AIS. Scale bars are 20 µm. (B) Background subtracted, mean intensity of total HA fluorescence in the AIS, distal axons, soma, and major dendrites. The sample number for each construct was as follows: WT (n = 27), A343D (n = 22), R353G (n = 21), and untransfected (n = 15). AU, arbitrary unit. Ave ± SEM (*p<0.05, ***p<0.001).