Figure 8.

STIM2 is required for STIM1 puncta formation. Subcellular localization of YFP-STIM1 in NIH 3T3 (A) WT, (B) KO2-1, or (C) KO2-1 cells transiently expressing CFP-STIM2. Cells were transfected with YFP-STIM1. Representative confocal images of cells at rest (left panels; Basal), after depleting ER stores with CPA in a Ca²⁺-free solution (center panels; 0Ca²⁺/20 μM CPA), and after re-administration of extracellular Ca²⁺ (right panels; 1 mM Ca²⁺ Wash). Scale bar = 10 μm. (D) Average area of individual puncta, and (E) average number of puncta per cell in ER Ca²⁺ store-depleted cells. Data were recorded from at least six independent experiments for each group of cells: WT (n = 19 cells), KO2-1 (n = 18 cells), and STIM2 reconstituted KO2-1 (n = 9 cells). * p < 0.05 compared to WT.