B. Traces showing average changes (mean±s.e.m.) in intracellular Ca2+ (Fura2 ratio) over time in response to perfusion of different [Ca2+]o as indicated in the upper bar with constructs as indicated expressed in HEKO1. STIM1 (black, n=145), STIM1A (red, n=157) and STIM1A_D503A (n=185). C. Relative fluorescence intensities of mCherry-tagged constructs measured in (B). D. Quantification of changes in resting ratio, TG peak (∆ ratio) and SOCE parameters measured in B. E. Data information: *P<0.05, **P<0.01 ***P<0.001 Kruskal-Wallis Anova with Dunn's multiple comparisons test. Data points (total n) were obtained from three biological replicates with each three technical replicates (each multiple cells) and shown as mean±s.e.m for traces and as scatter plots with the underlying boxes showing the means for individual parameters. 