Fig. 3.

Store-operated Ca²⁺ entry is increased in Stc2^−/− MEFs. (A) Fura-2-loaded WT and Stc2^−/− MEFs were perfused with HBSS containing 2 mM MnCl₂, followed by treatment with Tg (300 nM). Images were acquired at an excitation of 360 nm (the isosbestic point for Fura-2). Traces represent averages from at least 15 experiments. The inset shows average Mn²⁺ leak rates before the addition of Tg. (B) Average Mn²⁺ influx rate (corrected for Mn²⁺ leak) after Tg addition (means ± SEM). (C) WT and Stc2^−/− MEFs loaded with Fura-2 were perfused with HBSS containing 50 μM 2-APB, a specific inhibitor of SOCE, followed by treatment with Tg, perfusion in 0 Ca²⁺ HBSS, and Ca²⁺ add back in the presence of 2-APB. Traces represent averages from nine experiments. (D) Quantification of average [Ca²⁺]_i peaks after Tg addition (means ± SEM) in the presence of HBSS and 2-APB. *, P < 0.05 by Student's t test.