Regulation of the Cardiac Ryanodine Receptor Channel by Luminal Ca2+ Involves Luminal Ca2+ Sensing Sites
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چکیده
منابع مشابه
Ryanodine receptor luminal Ca2+ regulation: swapping calsequestrin and channel isoforms.
Sarcoplasmic reticulum (SR) Ca(2+) release in striated muscle is mediated by a multiprotein complex that includes the ryanodine receptor (RyR) Ca(2+) channel and the intra-SR Ca(2+) buffering protein calsequestrin (CSQ). Besides its buffering role, CSQ is thought to regulate RyR channel function. Here, CSQ-dependent luminal Ca(2+) regulation of skeletal (RyR1) and cardiac (RyR2) channels is exp...
متن کاملControl of cardiac ryanodine receptor by sarcoplasmic reticulum luminal Ca2+
Introduction Cardiac myocyte contraction is driven by the coordinated release of Ca from the sarcoplasmic reticulum (SR). This release of Ca occurs through the cardiac RyR2. Physiologically, Ca release occurs in response to an influx of Ca through L-type Ca channels, via a mechanism termed CICR. This transient increase in cytosolic Ca activates the RyR2 channel as a result of Ca binding to the ...
متن کاملCa2+ stores regulate ryanodine receptor Ca2+ release channels via luminal and cytosolic Ca2+ sites.
1. In muscle, intracellular calcium concentration, hence skeletal muscle force and cardiac output, is regulated by uptake and release of calcium from the sarcoplasmic reticulum. The ryanodine receptor (RyR) forms the calcium release channel in the sarcoplasmic reticulum. 2. The free [Ca2+] in the sarcoplasmic reticulum regulates the excitability of this store by stimulating the Ca2+ release cha...
متن کاملCaffeine induces Ca2+ release by reducing the threshold for luminal Ca2+ activation of the ryanodine receptor.
Caffeine has long been used as a pharmacological probe for studying RyR (ryanodine receptor)-mediated Ca(2+) release and cardiac arrhythmias. However, the precise mechanism by which caffeine activates RyRs is elusive. In the present study, we investigated the effects of caffeine on spontaneous Ca(2+) release and on the response of single RyR2 (cardiac RyR) channels to luminal or cytosolic Ca(2+...
متن کاملLuminal Ca2+ controls activation of the cardiac ryanodine receptor by ATP
The synergic effect of luminal Ca(2+), cytosolic Ca(2+), and cytosolic adenosine triphosphate (ATP) on activation of cardiac ryanodine receptor (RYR2) channels was examined in planar lipid bilayers. The dose-response of RYR2 gating activity to ATP was characterized at a diastolic cytosolic Ca(2+) concentration of 100 nM over a range of luminal Ca(2+) concentrations and, vice versa, at a diastol...
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ژورنال
عنوان ژورنال: Biophysical Journal
سال: 1998
ISSN: 0006-3495
DOI: 10.1016/s0006-3495(98)77723-9