Figure 2.

Increased basal activity in intact cells expressing K_ATP (G53D) channels. Relative efflux of ⁸⁶Rb⁺ as a function of time in basal conditions (A) or in the presence of metabolic inhibition (B) for reconstituted wild-type (WT) and mutant K_ATP channels, and untransfected controls (Unt). All transfections were done in parallel. Graphs show compiled data (mean ± sem) from four to six experiments. C, Rate constants for K_ATP-dependent efflux (k₂) in basal conditions relative to metabolic inhibition (MI) for WT, heteromeric, or homomeric K_ATP channels. Data were fit with a double-exponential equation to obtain rate constants for K_ATP-dependent efflux, k₂ (see Patient and Methods). *, P < 0.05 and **, P < 0.001, compared with wild-type K_ATP by unpaired Student’s t test.