Fig. 2.

Loss of STIM1 reduces oscillatory Ca²⁺ signals to LTC₄. (A) Oscillatory Ca²⁺ response after stimulation with 120 nM LTC₄ is shown for a control cell. (B) The oscillatory response is greatly reduced after knockdown of STIM1. (C) Aggregate data from 25 control cells and 31 STIM1 KD cells are compared. Bin number represents segments of 200 s, starting as soon as LTC₄ was applied. (D) Total store Ca²⁺ content is not significantly reduced after STIM1 KD. Five micromolar ionomycin was applied. (E) Ca²⁺ content of the thapsigargin-sensitive store was not reduced after STIM1 knockdown. Thapsigargin was applied at 2 μM. Only upper error bars for Control and lower error bars for STIM1 KD are shown. (F) Typical oscillatory Ca²⁺ responses are obtained after knock down of STIM1, when LTC₄ is applied in 0 Ca²⁺ plus 1 mM La³⁺.