Fig. S3.

Defects in voltage-activated global Ca²⁺ release in MTM1-deficient muscle fibers are alleviated by a prolonged exposure to PtdIns 3-kinase inhibitors. (A) Voltage dependence of the peak rate of Ca²⁺ release in WT (black symbols) and MTM1-deficient muscle fibers (red symbols) under control conditions (filled symbols, n = 7 and 8 WT and KO fibers, respectively) and following overnight exposure to the PtdIns 3-kinase inhibitors wortmannin and LY294002 (PtdIns 3-K block, open symbols, n = 8 and 9 WT and KO fibers, respectively). The Inset shows the mean values for the maximum rate of Ca²⁺ release in the different conditions: For this, a Boltzmann function was fitted to the individual sets of values in each fiber. (B) Voltage dependence of the mean time to peak rate of Ca²⁺ release in the different conditions. Black and red asterisks report a significant difference between WT and KO fibers and between KO fibers untreated and treated with the PtdIns 3-kinase blockers, respectively. All data are expressed as mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001 with unpaired t test.