Figure 5.

EGF and thrombin activate Ca²⁺ influx through Orai3. A–D) Ca²⁺ release and subsequent Ca²⁺ influx measured simultaneously in several MCF7 cells, in response to thapsigargin (A; n=32), EGF (B; n=30) and thrombin (C; n=29) and showing that 2-APB potentiated the Ca²⁺ influx in response to all three stimuli. D) MCF7 cells transfected with siOrai3 or siControl show that siOrai3 significantly abrogated Ca²⁺ influx in response to thrombin in comparison with siControl. E–H) Ca²⁺ release and subsequent Ca²⁺ influx measured simultaneously in several MDA-MB231 cells, in response to thapsigargin (E; n=56), EGF (F; n=39), and thrombin (G; n=19) and showing that 2-APB inhibited the Ca²⁺ influx in response to thapsigargin and thrombin (EGF caused no perceptible rise in either Ca²⁺ release or Ca²⁺ entry. Ionomycin (Iono, 10 μM) was added at the end of the recording as a control). H) MDA-MB231 cells transfected with siOrai1 or siControl show that siOrai1 significantly abrogated Ca²⁺ influx in response to thrombin in comparison with siControl. **P < 0.01, ***P < 0.001.