RyR1-mediated Ca²⁺-induced Ca²⁺ release plays a negligible role in excitation-contraction coupling of normal skeletal muscle.

ABSTRACT: Type 1 ryanodine receptor (RyR1) is a Ca²⁺ release channel in the sarcoplasmic reticulum in skeletal muscle. In excitation-contraction (E-C) coupling, RyR1 opens by depolarization of transverse tubule membrane via physical interaction with dihydropyridine receptor, which is referred to as depolarization-induced Ca²⁺ release (DICR). RyR1 can also be gated via Ca²⁺-induced Ca²⁺ release (CICR), in which binding of Ca²⁺ directly opens the channel. Thus, RyR1 has two Ca²⁺ release modes; DICR and CICR, but the physiological role of CICR has been a matter of debate: whether CICR can amplify Ca²⁺ signals in E-C coupling. To address this issue, we created a mouse model carrying a mutation in the Ca²⁺-binding sit

SUBMITTER: Kobayashi T 

PROVIDER: S-EPMC12403001 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature