Figure 3. The K⁺ channel function of TALK-1 contributes to its regulation of Ca²⁺_ER homeostasis.

(A) TALK-1b and -1a co-localize with the ER marker ER-YFP. Images are representative of 3 independent experiments. Scale bar is 10 µm. (B) Representative recordings of HEK293 cells expressing either WT TALK-1 or TALK-1 DN and perfused with the indicated solutions; 10 mM glucose was present throughout the experiment. (C) Normalized Ca²⁺ AUC for the period during treatment with CPA (t=250–600 s). (D) Ca²⁺ AUC for the period following addition of 2.5 mM Ca²⁺ to the extracellular buffer (t=1000–1750 s). (E) Fold increase in Ca²⁺ in response to treatment with the muscarinic receptor agonist carbachol (N = 3 independent experiments for B to D). Statistical significance was determined by Student’s t-test; *P<0.05, **P<0.01, ***P<0.005.