Regulatory mechanisms of ryanodine receptor/Ca release channel revealed by recent advancements in structural studies.

Ryanodine receptors (RyRs) are huge homotetrameric Ca release channels localized to the sarcoplasmic reticulum. RyRs are responsible for the release of Ca from the SR during excitation-contraction coupling in striated muscle cells. Recent revolutionary advancements in cryo-electron microscopy have provided a number of near-atomic structures of RyRs, which have enabled us to better understand the architecture of RyRs. Thus, we are now in a new era understanding the gating, regulatory and disease-causing mechanisms of RyRs. Here we review recent advances in the elucidation of the structures of RyRs, especially RyR1 in skeletal muscle, and their mechanisms of regulation by small molecules, associated proteins and disease-causing mutations.