FIGURE 4.

Generation and characterization of Ca²⁺ homeostasis in HEK-APPswe cells. A, HEK cells stably expressing APPswe were transduced with empty vector or Orai1_myc followed by transient transfection with YFP-STIM1 or YFP-STIM1_D76A. Western blot analysis confirmed successful expression of Orai1_myc, YFP-STIM1, or YFP-STIM1_D76A, and APPswe. B and C, Fura-2 AM-loaded HEK-APPswe (B) and HEK-APPswe-Orai (C) cells were imaged to quantify Ca²⁺ entry phenotypes induced by YFP-STIM1 or YFP-STIM1_D76A expression as described in Fig. 2. D, stably-transduced HEK-Orai cells (without APP overexpression) were transfected with empty vector control or YFP-STIM1 and subsequently loaded with Fura-4F for Ca²⁺ imaging. After perfusion in HBSS, 1 μm Tg was added in 0 Ca²⁺ HBSS to deplete Ca²⁺ stores followed by perfusion in HBSS to trigger SOCE. Data represent four experiments with ∼50 cells per experiment.