9ol6
From Proteopedia
Rabbit Ryanodine Receptor 1: DMSO Control Closed Conformation
Structural highlights
FunctionRYR1_RABIT Calcium channel that mediates the release of Ca(2+) from the sarcoplasmic reticulum into the cytoplasm and thereby plays a key role in triggering muscle contraction following depolarization of T-tubules. Repeated very high-level exercise increases the open probability of the channel and leads to Ca(2+) leaking into the cytoplasm. Can also mediate the release of Ca(2+) from intracellular stores in neurons, and may thereby promote prolonged Ca(2+) signaling in the brain. Required for normal embryonic development of muscle fibers and skeletal muscle. Required for normal heart morphogenesis, skin development and ossification during embryogenesis (By similarity).[1] [2] Publication Abstract from PubMedStatins are the most prescribed class of drugs and inhibit a key enzyme in the cholesterol biosynthesis pathway. Many patients have reported mild to severe muscle related symptoms and a subset are at risk for rhabdomyolysis. Sequence variants in RyR1, the skeletal muscle Ryanodine Receptor, correlate with intolerance to statins, but whether RyR1 can bind statins directly has remained unclear. Here we report cryo-EM structures of RyR1 in the absence and presence of atorvastatin, firmly establishing RyR1 as an unintended off-target. Our results show an unusual binding mode whereby three atorvastatin molecules bind together in a cleft formed by the pseudo-voltage sensing domain, making extensive interactions with each other and with RyR1. Atorvastatin activates RyR1 in a sequential way, whereby one statin per subunit can bind to the transmembrane region of a closed RyR1, with small structural perturbations that prime the channel for opening. Binding of two additional statins per subunit is associated with a widening of the pseudo-voltage sensing domain that triggers opening of the pore. Comparison with atorvastatin binding to HMG-CoA reductase, its intended target, offers clues on how to modify the statin to reduce RyR1 binding, while leaving binding to HMG-CoA reductase unperturbed. Cryo-electron microscopy reveals sequential binding and activation of Ryanodine Receptors by statin triplets.,Molinarolo S, Valdivia CR, Valdivia HH, Van Petegem F Nat Commun. 2025 Nov 20. doi: 10.1038/s41467-025-66522-0. PMID:41266329[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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