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Dual role of junctin in the regulation of ryanodine receptors and calcium release in cardiac ventricular myocytes
Author(s) -
Altschafl Beth A.,
Arvanitis Demetrios A.,
Fuentes Oscar,
Yuan Qunying,
Kranias Evangelia G.,
Valdivia Héctor H.
Publication year - 2011
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2011.215988
Subject(s) - ryanodine receptor , medicine , calcium , myocyte , receptor , endocrinology , chemistry , microbiology and biotechnology , biology
Non‐technical summary Each heartbeat is accompanied by the coordinated release of calcium ions into cardiac cells through ryanodine receptors, which span the membrane of the sarcoplasmic reticulum. We show that an intra‐sarcoplasmic reticulum protein, junctin, interacts with ryanodine receptor channels and appears to activate them when calcium inside the sarcoplasmic reticulum is low. Conversely, junctin appears to act as an inhibitor of ryanodine receptors when calcium inside the sarcoplasmic reticulum is high. Knowledge of how junctin interacts with ryanodine receptors helps us to understand how calcium within the sarcoplasmic reticulum helps to regulate ryanodine receptor activity in normal hearts and also helps us to understand why junctin is decreased in patients diagnosed with certain forms of heart failure.