FIGURE 8:

Mutations that eliminate K⁺ conductance do not impact Kv2.2 channel clustering. (A) Exemplar whole-cell voltage clamp recordings (left) and corresponding graphs of current levels vs. command voltage (right) of HEK293T cells expressing GFP (control), GFP-Kv2.2, GFP-Kv2.2 P412W, GFP-Kv2.1, or GFP-Kv2.1 P404W. Recordings shown are representative responses to 100-ms steps from –100 mV to –40, 0, and +40 mV. Note the lack of outward currents in control, GFP-Kv2.2 P412W, and GFP-Kv2.1 P404W recordings. (B, C) Summary graphs showing whole cell current at +40 mV for cells expressing Kv2.2 (B) or Kv2.1 (C) isoforms. See Supplemental Table 13 for values and statistical analyses for B and C. (D) Deconvolved widefield image of a live CHN expressing GFP-Kv2.2 P412W or GFP-Kv2.1 P404W. Scale bar is 5 µm and holds for both panels. (E) TIRF images of live HEK293T cells expressing GFP-Kv2.2 P412W or GFP-Kv2.1 P404W and surface labeled with GxTX-633. Scale bar in the Kv2.2 P412W panel is 5 µm and hold for all panels. (F, G) Graphs of mean cluster size per cell measured from CHNs expressing GFP-Kv2.2 or GFP-Kv2.2 P412W (F) or GFP-Kv2.1 or GFP-Kv2.1 P404W (G). Bars are mean ± SD. See Supplemental Table 14 for values and statistical analyses for F and G. (H, I) Graph of PCC between Kv2 and GxTX from HEK293T cells expressing GFP-Kv2.2 or GFP-Kv2.2 P412W (H) or GFP-Kv2.1 or GFP-Kv2.1 P404W (I). Bars are mean ± SD. See Supplemental Table 15 for values and statistical analyses for H and I.