Figure 2

Suppression of STIM1 results in decreased store operated calcium influx. (a) A representative raw trace illustrating the changes in [Ca²⁺]_i (presented as fluorescence intensity (FI)) in HASMs treated with STIM-1 siRNA. CPA (10 μM) was added to the cells in the presence of low extracellular Ca²⁺ (0.1 mM) followed by the restoration of 2 mM Ca²⁺ as indicated. (b) Summary of the data illustrated in (a) showing averaged changes in fluorescence after 2 mM Ca²⁺ restoration. (c) A representative trace illustrating changes in [Ca²⁺]_i in HASMs treated with STIM-2 siRNA following the same protocol. (d) Summary of the data illustrated in (c) showing averaged changes in fluorescence after 2 mM Ca²⁺ restoration. The summarized data (c & d) are shown following subtraction of CPA independent (basal) calcium influx (measured as the fluorescence change upon addition of 2 mM Ca²⁺ to cells not pre-treated with CPA). (e) An experimental trace illustrating CPA independent (basal) Ca²⁺ influx. Results are expressed as % changes ± sem compared to control and represent averaged data from 4 separate experiments. Data are indicated as statistically significant with *P < 0.05 and **P < 0.01.