Fig. 3: Truncation of the N-terminal domains A and B in RyR2 inhibits intersubunit disulfide cross-linking and diamide-induced depletion in [Ca2+]ER.

a Representative western blot image of the hRyR2 cross-linking caused by diamide in HEK293 cells expressing GFP-hRyR2 and hRyR2^ΔAB. All representative western blot images are presented as a top part, above the MW of 250 kDa, including the loading wells area. b Summary of the effect of the increasing diamide concentrations on the level of RyR2 monomeric form for hRyR2^WT and hRyR2^ΔAB channels expressed in HEK293 cells. Data are shown as means ± SE (n = 4, each n represents data from an independent experiment) and were analyzed using a two-sided unpaired t-test. c Representative recordings of Ca²⁺ waves from HEK293 cells expressing hRyR2^WT (black) and hRyR2^ΔAB (red) in control condition followed by the application of 50 µM diamide. The dashed lines indicate the level of ER Ca²⁺ load. Caffeine (Caf; 10 mM) and ionomycin (2 µM) in 10 mM Ca²⁺ were used to normalize the signal. d Summary of the effect of 50 µM diamide on ER Ca²⁺ load in HEK293 cells transfected with hRyR2^WT (black) or hRyR2^ΔAB (red). Data are shown as means ± SE (n = 22 for hRyR2^WT and 20 cells for hRyR2^ΔAB) and were analyzed using a two-sided unpaired t-test.