Conditional ablation of β-cell TASK-1 reduces K2P current amplitude. A, Islet DNA from floxed KCNK3 MIP-Cre/ERT mice treated with tamoxifen or vehicle (corn oil) and assessed for exon-2 excision via PCR with the primers indicated by numbers 1 to 3. B, Western blot analysis of islet protein probed with TASK-1 and GAPDH antibodies. C, β-Cell TASK-1 currents from KCNK3 floxed MIP-Cre/ERT mice with or without 250nM A1899 treatment (gray trace and black outlined trace) or MIP-Cre/ERT mice (black trace) all treated with tamoxifen (the currents are normalized to cell capacitance; currents recorded in 14mM glucose, 100μM tolbutamide, and 20mM TEA; currents recorded in response to a voltage ramp from −120 mV to 60 mV over a 1-second interval). D, Average TASK-like current amplitude at +60 mV from control β-cells (black bar) and TASK-1–deficient β-cells with and without 250nM A1899 (gray bar and white bar, ±SEM; *, P < .05).