Supplementary Figure 6: ATP induces similar currents in Pkd2^+/+ and Pkd2^−/− MEFs and WNT9B does not induce Ca²⁺ release in these cells.

Time course (a,d), step-currents (b,e), and I–V curves (c,f) of ATP (100 μM)—induced whole cell currents in 100 nM of intracellular Ca²⁺ concentration in Pkd2^+/+ (n = 7 cells pooled from 3 independent experiments) and Pkd2^−/− MEFs (n = 9 cells pooled from 3 independent experiments). Step-currents represent maximum currents. I–V curves were taken before the addition of ATP (black lines) and at maximum currents (red lines). Representative images of time courses (a,d) and step currents (b,e) are shown from 7, 9 cells, respectively. (g) Time course of WNT9B-induced Δ[Ca²⁺]_i (shown as fluorescence ratio 340/380) in Pkd2^+/+ (n = 47 pooled from 3 independent experiments) and Pkd2^−/− cells (n = 37 cells pooled from 3 independent experiments) bathed in Ca²⁺ free extracellular solution (0.5 mM EGTA). (h) Summary data of ATP-induced Ca²⁺ release transients (peak levels) in Pkd2^+/+ and Pkd2^−/− MEFs. Box and whiskers graph (line: median, box: distribution of 50% of values, whiskers: minimum to maximum). Statistical test was performed using unpaired Student’s t-test, N.S means non-significant. Data are shown as mean ± s.e.m.