The cardiac ryanodine receptor, but not sarcoplasmic reticulum Ca2+-ATPase, is a major determinant of Ca2+ alternans in intact mouse hearts

B Sun, J Wei, X Zhong, W Guo, J Yao, R Wang… - Journal of Biological …, 2018 - jbc.org
Sarcoplasmic reticulum (SR) Ca 2+ cycling is governed by the cardiac ryanodine receptor
(RyR2) and SR Ca 2+-ATPase (SERCA2a). Abnormal SR Ca 2+ cycling is thought to be the
primary cause of Ca 2+ alternans that can elicit ventricular arrhythmias and sudden cardiac
arrest. Although alterations in either RyR2 or SERCA2a function are expected to affect SR
Ca 2+ cycling, whether and to what extent altered RyR2 or SERCA2a function affects Ca 2+
alternans is unclear. Here, we employed a gain-of-function RyR2 variant (R4496C) and the …