Figure 1.

Translocon (TLC) activation by puromycin induces a decrease in reticular Ca²⁺ stock. (A) Illustration of the in vivo adenoviral strategy to express a reticular Ca²⁺ sensor, D4ER, in adult mouse cardiomyocytes, presenting a typical reticular pattern of the fluorescent sensor as displayed on the representative confocal image. Scale bar: 50 µm. (B) Graphical representation of the D4ER fluorescence ratio evolution with time in control condition (black line) and in response to 30 min of 200 µM puromycin treatment (red line), both stimulated with 5 mM caffeine; representative curve of reticular fluorescence evolution in control (Ctrl) condition and under puromycin treatment. (C) Scatter plots of reticular Ca²⁺ decreased at the end of 30 min perfusion with or without puromycin. (D) Scatter plots of the ryanodine receptor (RyR)-dependent reticular Ca²⁺ stock after puromycin or Ctrl treatment estimated by caffeine stimulation, calculated as difference between fluorescence level at stimulation time and final fluorescence. n = cell count. Statistics: ⁺⁺ p < 0.01 vs. Ctrl.