Fig 5. Effect of the H29D mutation on the propensity for SOICR in HEK293 cells.

Stable, inducible HEK293 cells expressing RyR2 WT and the H29D mutant were loaded with 5 μM Fura-2 AM in KRH buffer. The cells were then perfused continuously with KRH buffer containing increasing levels of extracellular Ca²⁺ (0–2 mM) to induce SOICR. Fura-2 ratios of representative RyR2 WT (A) and H29D (B) cells were recorded using epifluorescence single cell Ca²⁺ imaging. (C) The percentages of RyR2 WT (total 1087 cells) and H29D (total 1161 cells) cells that display Ca²⁺ oscillations at various extracellular Ca²⁺ concentrations. Data shown are mean ± SEM (n = 9–10).