Figure 5.

L220F affects phosphatidylinositol 4,5-bisphosphate (PIP₂)-dependent gating of ROMK. Whole-cell potassium currents recorded in Xenopus oocytes coexpressing the M1 receptor with ROMK channels comprising wild type (WT) and/or L220F mutant subunits. Relative doses are given in parentheses. Data are expressed as the percent inhibition of the potassium current induced by exposure (10 min) to carbachol (25 μmol/L) and are mean ± SEM (n = 12–15 oocytes/group, from three frogs). ***P < 0.001; ns, P > 0.05 versus inhibition of WT potassium current.