ArticleBiophysical journal2002
Ca2+ activation of RyR1 is not necessary for the initiation of skeletal-type excitation-contraction coupling.
Article in Biophysical journal, 2002. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.
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Who cites it
11 citing papers in PubMed, 26 citations in OpenAlex.
- The central domain of cardiac ryanodine receptor governs channel activation, regulation, and stability.The Journal of biological chemistry · 2020Article
- Preclinical model systems of ryanodine receptor 1-related myopathies and malignant hyperthermia: a comprehensive scoping review of works published 1990-2019.Orphanet journal of rare diseases · 2020Article
- CaThe Journal of biological chemistry · 2018Article
- Aging impairs regulation of ryanodine receptors from extensor digitorum longus but not soleus muscles.Muscle & nerve · 2018Article
- Enhanced Cytosolic Ca2+ Activation Underlies a Common Defect of Central Domain Cardiac Ryanodine Receptor Mutations Linked to Arrhythmias.The Journal of biological chemistry · 2016Article
- Luminal Ca2+-regulated Mg2+ inhibition of skeletal RyRs reconstituted as isolated channels or coupled clusters.The Journal of general physiology · 2004Article
- Evidence for conformational coupling between two calcium channels.Proceedings of the National Academy of Sciences of the United States of America · 2004Article
- Cardiac-type EC-coupling in dysgenic myotubes restored with Ca2+ channel subunit isoforms alpha1C and alpha1D does not correlate with current density.Biophysical journal · 2003Article
- Store operated Ca2+ influx by selective depletion of ryanodine sensitive Ca2+ pools in primary human skeletal muscle cells.Naunyn-Schmiedeberg's archives of pharmacology · 2003Article
- Excitation-contraction coupling and fatigue mechanisms in skeletal muscle: studies with mechanically skinned fibres.Journal of muscle research and cell motility · 2002Review
- Hair cells--beyond the transducer.The Journal of membrane biologyReview
Corrections and comments
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Authors and funding
6 authors at 3 institutions in 1 country.
Funding
Abstract
Although an elevation in myoplasmic Ca2+ can activate the skeletal muscle ryanodine receptor (RyR1), the function of this Ca2+ activation is unclear because extracellular Ca2+ influx is unnecessary for skeletal-type EC coupling. To determine whether Ca2+ activation of RyR1 is necessary for the initiation of skeletal-type EC coupling, we examined the behavior of RyR1 with glutamate 4032 mutated to alanine (E4032A-RyR1) because this mutation had been shown to dramatically reduce activation by Ca2+. Proc. Natl. Acad. Sci. USA. 98:2865-2870). Analysis after reconstitution into planar lipid bilayers revealed that E4032A-RyR1 was negligibly activated by 100 microM Ca2+ (P(o) too low to be measured). Even in the presence of both 2 mM caffeine and 2 mM ATP, P(o) remained low for E4032A-RyR1 (ranging from <0.0001 in 100 microM free Ca2+ to 0.005 in 2 mM free Ca2+). Thus, the E4032A mutation caused a nearly complete suppression of activation of RyR1 by Ca2+. Depolarization of E4032A-RyR1-expressing myotubes elicited L-type Ca2+ currents of approximately normal size and myoplasmic Ca2+ transients that were skeletal-type, but about fivefold smaller than those for wild-type RyR1. The reduced amplitude of the Ca2+ transient is consistent either with the possibility that Ca2+ activation amplifies Ca2+ release during EC coupling, or that the E4032A mutation generally inhibits activation of RyR1. In either case, Ca2+ activation of RyR1 does not appear to be necessary for the initiation of Ca2+ release during EC coupling in skeletal muscle.
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Registered trials
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