Fig. 6.

CPVT-associated mutations N53I and A102V affect spontaneous Ca²⁺ transients in cells. HEK293T cells transfected with RyR2 and CaM variants were loaded with Calbryte 520 to monitor intracellular Ca²⁺ concentration changes. Live cells were imaged on a 3i spinning-disk confocal microscope. (A-D) Representative fluorescence signals in HEK293T cells expressing RyR2 (A) with CaM-WT (B), CaM-N53I (C) and CaM-A102V (D). (E-J) Analysis of the Ca²⁺ transients kinetic parameters using Analyse Spikes applet for Matlab and Fiji (Schindelin et al., 2012). Data are mean±s.e.m. The numbers of experimental replicates for the oscillations experiments (N=dishes, n=fields of view) were as follows: N=6, n=20 for CaM-WT; N=6, n=16 for CaM-N53I; and N=6, n=19 for CaM-A102V. *P<0.05; **P<0.01; ***P<0.001; ****P<0.0001 (versus CaM-WT; differences between the groups were determined using one-way ANOVA with Dunnett's post-hoc test). F.U., fluorescence unit; ΔF, difference between the maximum fluorescence and the initial fluorescence; F₀, initial fluorescence.