National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIH/NIAMS)
R01 AR068431
米国
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
R01 HL133182
米国
Other private
MDA 352845
米国
American Heart Association
19POST34430178
米国
National Institutes of Health/National Cancer Institute (NIH/NCI)
HSSN26120080001E
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
U24 GM116789
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
U24 GM116790
米国
引用
ジャーナル: Sci Adv / 年: 2020 タイトル: Structural mechanism of two gain-of-function cardiac and skeletal RyR mutations at an equivalent site by cryo-EM. 著者: Kavita A Iyer / Yifan Hu / Ashok R Nayak / Nagomi Kurebayashi / Takashi Murayama / Montserrat Samsó / 要旨: Mutations in ryanodine receptors (RyRs), intracellular Ca channels, are associated with deadly disorders. Despite abundant functional studies, the molecular mechanism of RyR malfunction remains ...Mutations in ryanodine receptors (RyRs), intracellular Ca channels, are associated with deadly disorders. Despite abundant functional studies, the molecular mechanism of RyR malfunction remains elusive. We studied two single-point mutations at an equivalent site in the skeletal (RyR1 R164C) and cardiac (RyR2 R176Q) isoforms using ryanodine binding, Ca imaging, and cryo-electron microscopy (cryo-EM) of the full-length protein. Loss of the positive charge had greater effect on the skeletal isoform, mediated via distortion of a salt bridge network, a molecular latch inducing rotation of a cytoplasmic domain, and partial progression to open-state traits of the large cytoplasmic assembly accompanied by alteration of the Ca binding site, which concur with the major "hyperactive" feature of the mutated channel. Our cryo-EM studies demonstrated the allosteric effect of a mutation situated ~85 Å away from the pore and identified an isoform-specific structural effect.