Figure 2. Specific knockdown of STIM2.1 alters SOCE in primary cells.

(a) Relative expression of STIM1, STIM2.1 and STIM2.2 after transfection with siRNA against exon 9 (STIM2.1) red or siRNA against exon 8/10 boundary (b, STIM2.2, blue), corresponding control transfection, black bars. (c) Traces showing average changes in intracellular Ca²⁺ concentration [Ca²⁺]_i over time in CD4⁺ T cells transfected with control (black, n=698) or siRNA against STIM2.1 (red, n=579) in response to perfusion of different [Ca²⁺]_o indicated in the upper bar. (d–g) Quantification of changes in [Ca²⁺]_i measured in c. (h) Traces showing changes in [Ca²⁺]_i in CD4⁺ T cells treated as in c after transfection with control (black, n=978) or siRNA against STIM2.2 (blue, n=776). (i–l) Quantification of changes in [Ca²⁺]_i measured in h. Measurements shown in c–l are obtained from cells of three independent blood donors and ⩾8 experiments. *P<0.05, **P<0.01, ***P<0.001, Student's T-test. Data obtained are presented as mean±s.e.m.