Slaying a giant: Structures of calmodulin and protein kinase a bound to the cardiac ryanodine receptor.

Ryanodine Receptors are Ca²⁺ release channels expressed in the Endoplasmic and Sarcoplasmic Reticulum membranes. Gong et al [1] reported cryo-EM structures of the cardiac RyR2 complexed to Calmodulin, which can downregulate channel opening. Haji-Ghassemi et al [2] report crystal structures of an RyR2 domain with PKA, a kinase promoting channel opening. [ABSTRACT FROM AUTHOR]