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The ryanodine receptor store-sensing gate controls Ca2+ waves and Ca2+-triggered arrhythmias
Journal article   Peer reviewed

The ryanodine receptor store-sensing gate controls Ca2+ waves and Ca2+-triggered arrhythmias

Wenqian Chen, Ruiwu Wang, Biyi Chen, Xiaowei Zhong, Huihui Kong, Yunlong Bai, Qiang Zhou, Cuihong Xie, Jingqun Zhang, Ang Guo, …
Nature medicine, Vol.20(2), pp.184-192
02/2014
DOI: 10.1038/nm.3440
PMCID: PMC4269524
PMID: 24441828
url
https://www.ncbi.nlm.nih.gov/pmc/articles/4269524View
Open Access

Abstract

Spontaneous Ca(2+) release from intracellular stores is important for various physiological and pathological processes. In cardiac muscle cells, spontaneous store overload-induced Ca(2+) release (SOICR) can result in Ca(2+) waves, a major cause of ventricular tachyarrhythmias (VTs) and sudden death. The molecular mechanism underlying SOICR has been a mystery for decades. Here we show that a point mutation, E4872A, in the helix bundle crossing region (the proposed gate) of the cardiac ryanodine receptor (RyR2) completely abolishes luminal, but not cytosolic, Ca(2+) activation of RyR2. The introduction of metal-binding histidines at this site converts RyR2 into a luminal Ni(2+)-gated channel. Mouse hearts harboring a heterozygous RyR2 mutation at this site (E4872Q) are resistant to SOICR and are completely protected against Ca(2+)-triggered VTs. These data show that the RyR2 gate directly senses luminal (store) Ca(2+), explaining the regulation of RyR2 by luminal Ca(2+), the initiation of Ca(2+) waves and Ca(2+)-triggered arrhythmias. This newly identified store-sensing gate structure is conserved in all RyR and inositol 1,4,5-trisphosphate receptor isoforms.
Animals Arrhythmias, Cardiac - etiology Arrhythmias, Cardiac - metabolism Caffeine Calcium - metabolism DNA Primers - genetics Echocardiography Gene Knock-In Techniques HEK293 Cells Humans Immunoblotting Lipid Bilayers - metabolism Mice Microscopy, Confocal Mutagenesis, Site-Directed Myocytes, Cardiac - metabolism Patch-Clamp Techniques Point Mutation - genetics Ryanodine Receptor Calcium Release Channel - genetics Ryanodine Receptor Calcium Release Channel - metabolism

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