Screen of several gain-of-function point mutations for the ability to rescue P271A and E275A Slo2.1 channels. (A) Effect of 1 and 6 mM NFA on I-Vt relationships for oocytes expressing WT channels (n = 4). Oocytes were injected with 10 ng cRNA, and currents were recorded 2 d later. (B) I-Vt relationships for uninjected oocytes treated with NFA (n = 9). 1 mM NFA had no effect, but 6 mM NFA activated a relatively small endogenous current. (C–F) I-Vt relationships showing that E275D and R190E, but not F240C or A278R, can rescue P271A channel function (n = 4–7). (G and H) I-Vt relationships showing that R190E (n = 7) and F240C (n = 10) do not rescue E275A channels. For B–H, oocytes were injected with 10 ng cRNA, and currents were recorded after incubation for 2 d (C) or 3–4 d (B and D–H). Error bars indicate mean ± SEM.
