FIGURE 3.

E2 inhibits SOCE and STIM1 oligomerization in HEK293T cells. A, typical changes in Fura-2 emission ratio in HEK293T cells acutely exposed to vehicle or E2 in Ca²⁺-free Ringer's solution and when 2 mm Ca²⁺ was added back to the Ringer's solution. B, mean differences in Fura-2 emission ratio taken from A. *, significant difference (unpaired t test; p = 0.0049). Control (white bars), both n = 53; E2 (black bars), both n = 57. C, typical confocal micrographs of STIM1-YFP (green, donor) and STIM1-mCherry (red, acceptor) before and after photobleaching of STIM1-mCherry in control cells under basal conditions. Cells were also expressing ESR1-CFP (data not shown). D, mean STIM1-STIM1 FRET efficiency (%E) in HEK293T cells. Ctrl, basal n = 31, TG n = 35; E2, basal n = 26, TG n = 25. *, significant difference (one-way ANOVA followed by Tukey's multiple comparison test; p < 0.001). Data are shown as mean ± S.E. Scale bar represents 10 μm.