scholarly journals Distribution and Function of Cardiac Ryanodine Receptor Clusters in Live Ventricular Myocytes

2015 ◽  
Vol 290 (33) ◽  
pp. 20477-20487 ◽  
Author(s):  
Florian Hiess ◽  
Alexander Vallmitjana ◽  
Ruiwu Wang ◽  
Hongqiang Cheng ◽  
Henk E. D. J. ter Keurs ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Ventricular Myocytes ◽  
Receptor Clusters ◽  
And Function ◽  
Cardiac Ryanodine Receptor

scholarly journals 3D visualisation of the cardiac ryanodine receptor clusters and the molecular-scale fraying of dyads

2021 ◽  
Author(s):  
Thomas M. D. Sheard ◽  
Miriam E. Hurley ◽  
Andrew J Smith ◽  
John Colyer ◽  
Ed White ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Ryanodine Receptor ◽  
Ventricular Myocytes ◽  
Three Dimensional ◽  
Super Resolution ◽  
Structural Protein ◽  
3D Visualisation ◽  
Central Regions ◽  
Molecular Machinery ◽  
Receptor Clusters

Clusters of ryanodine receptor calcium channels (RyRs) form the primary molecular machinery in cardiomyocytes. Various adaptations of super-resolution microscopy have revealed intricate details of the structure, molecular composition and locations of these couplons. However, most optical super-resolution techniques lack the capacity for three-dimensional (3D) visualisation. Enhanced Expansion Microscopy (EExM) offers resolution (in-plane and axially) sufficient to spatially resolve individual proteins within peripheral couplons and within dyads located in the interior. We have combined immunocytochemistry and immunohistochemistry variations of EExM with 3D visualisation to examine the complex topologies, geometries and molecular sub-domains within RyR clusters. We observed that peripheral couplons exhibit variable co-clustering ratios and patterns between RyR and the structural protein, junctophilin-2 (JPH2). Dyads possessed sub-domains of JPH2 which occupied the central regions of the RyR cluster, whilst the poles were typically devoid of JPH2 and broader, and likely specialise in turnover and remodelling of the cluster. In right ventricular myocytes from rats with monocrotaline-induced right ventricular failure, we observed hallmarks of RyR cluster fragmentation accompanied by similar fragmentations of the JPH2 sub-domains. We hypothesise that the frayed morphology of RyRs in close proximity to fragmented JPH2 structural sub-domains may form the primordial foci of RyR mobilisation and dyad remodelling.

scholarly journals Cardiac ryanodine receptor distribution is dynamic and changed by auxiliary proteins and post-translational modification

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Parisa Asghari ◽  
David RL Scriven ◽  
Myles Ng ◽  
Pankaj Panwar ◽  
Keng C Chou ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Ventricular Myocytes ◽  
Electron Tomography ◽  
Wistar Rat ◽  
Confocal Imaging ◽  
Post Translational Modification ◽  
Functional Changes ◽  
Cellular Environment ◽  
And Function ◽  
Correlation Microscopy

The effects of the immunophilins, FKBP12 and FKBP12.6, and phosphorylation on type II ryanodine receptor (RyR2) arrangement and function were examined using correlation microscopy (line scan confocal imaging of Ca2+ sparks and dual-tilt electron tomography) and dSTORM imaging of permeabilized Wistar rat ventricular myocytes. Saturating concentrations (10 µmol/L) of either FKBP12 or 12.6 significantly reduced the frequency, spread, amplitude and Ca2+ spark mass relative to control, while the tomograms revealed both proteins shifted the tetramers into a largely side-by-side configuration. Phosphorylation of immunophilin-saturated RyR2 resulted in structural and functional changes largely comparable to phosphorylation alone. dSTORM images of myocyte surfaces demonstrated that both FKBP12 and 12.6 significantly reduced RyR2 cluster sizes, while phosphorylation, even of immunophilin-saturated RyR2, increased them. We conclude that both RyR2 cluster size and the arrangement of tetramers within clusters is dynamic and respond to changes in the cellular environment. Further, these changes affect Ca2+ spark formation.

scholarly journals Muscarinic-dependent phosphorylation of the cardiac ryanodine receptor by protein kinase G is mediated by PI3K–AKT–nNOS signaling

2020 ◽  
Vol 295 (33) ◽  
pp. 11720-11728 ◽  
Author(s):  
Stephen Baine ◽  
Justin Thomas ◽  
Ingrid Bonilla ◽  
Marina Ivanova ◽  
Andriy Belevych ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Ryanodine Receptor ◽  
Soluble Guanylate Cyclase ◽  
Ventricular Myocytes ◽  
Cardiac Contractility ◽  
Calcium Handling ◽  
Protein Kinase G ◽  
Signaling Axis ◽  
Cardiac Ryanodine Receptor

Post-translational modifications of proteins involved in calcium handling in myocytes, such as the cardiac ryanodine receptor (RyR2), critically regulate cardiac contractility. Recent studies have suggested that phosphorylation of RyR2 by protein kinase G (PKG) might contribute to the cardioprotective effects of cholinergic stimulation. However, the specific mechanisms underlying these effects remain unclear. Here, using murine ventricular myocytes, immunoblotting, proximity ligation as-says, and nitric oxide imaging, we report that phosphorylation of Ser-2808 in RyR2 induced by the muscarinic receptor agonist carbachol is mediated by a signaling axis comprising phosphoinositide 3-phosphate kinase, Akt Ser/Thr kinase, nitric oxide synthase 1, nitric oxide, soluble guanylate cyclase, cyclic GMP (cGMP), and PKG. We found that this signaling pathway is compartmentalized in myocytes, as it was distinct from atrial natriuretic peptide receptor–cGMP–PKG–RyR2 Ser-2808 signaling and independent of muscarinic-induced phosphorylation of Ser-239 in vasodilator-stimulated phosphoprotein. These results provide detailed insights into muscarinic-induced PKG signaling and the mediators that regulate cardiac RyR2 phosphorylation critical for cardiovascular function.

scholarly journals Analysis of Cav1.2 and Ryanodine Receptor Clusters in Rat Ventricular Myocytes

2010 ◽  
Vol 99 (12) ◽  
pp. 3923-3929 ◽  
Author(s):  
David R.L. Scriven ◽  
Parisa Asghari ◽  
Meredith N. Schulson ◽  
Edwin D.W. Moore
Keyword(s):  
Ryanodine Receptor ◽  
Ventricular Myocytes ◽  
Rat Ventricular Myocytes ◽  
Receptor Clusters

Human Cardiac Ryanodine Receptor: Preparation, Crystallization and Preliminary X-ray Analysis of the N-terminal Region

2013 ◽  
Vol 20 (11) ◽  
pp. 1211-1216 ◽  
Author(s):  
L’ubomír Borko ◽  
Július Kostan ◽  
Alexandra Zahradníkova ◽  
Vladimír Pevala ◽  
Juraj Gasperík ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Terminal Region ◽  
X Ray ◽  
Cardiac Ryanodine Receptor

Antiarrhythmic Potential of Drugs Targeting the Cardiac Ryanodine Receptor Ca2+ Release Channel: Case Study of Dantrolene

2014 ◽  
Vol 21 (8) ◽  
pp. 1062-1072 ◽  
Author(s):  
Karoly Acsai ◽  
Norbert Nagy ◽  
Zoltan Marton ◽  
Kinga Oravecz ◽  
Andras Varro
Keyword(s):  
Ryanodine Receptor ◽  
Release Channel ◽  
Cardiac Ryanodine Receptor

scholarly journals Loss of dysferlin or myoferlin results in differential defects in excitation–contraction coupling in mouse skeletal muscle

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David Y. Barefield ◽  
Jordan J. Sell ◽  
Ibrahim Tahtah ◽  
Samuel D. Kearns ◽  
Elizabeth M. McNally ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Calcium Binding ◽  
Physiological Role ◽  
Muscle Disease ◽  
Calcium Handling ◽  
Membrane Repair ◽  
Tubule Formation ◽  
Ec Coupling ◽  
Associated Proteins ◽  
Receptor Clusters

AbstractMuscular dystrophies are disorders characterized by progressive muscle loss and weakness that are both genotypically and phenotypically heterogenous. Progression of muscle disease arises from impaired regeneration, plasma membrane instability, defective membrane repair, and calcium mishandling. The ferlin protein family, including dysferlin and myoferlin, are calcium-binding, membrane-associated proteins that regulate membrane fusion, trafficking, and tubule formation. Mice lacking dysferlin (Dysf), myoferlin (Myof), and both dysferlin and myoferlin (Fer) on an isogenic inbred 129 background were previously demonstrated that loss of both dysferlin and myoferlin resulted in more severe muscle disease than loss of either gene alone. Furthermore, Fer mice had disordered triad organization with visibly malformed transverse tubules and sarcoplasmic reticulum, suggesting distinct roles of dysferlin and myoferlin. To assess the physiological role of disorganized triads, we now assessed excitation contraction (EC) coupling in these models. We identified differential abnormalities in EC coupling and ryanodine receptor disruption in flexor digitorum brevis myofibers isolated from ferlin mutant mice. We found that loss of dysferlin alone preserved sensitivity for EC coupling and was associated with larger ryanodine receptor clusters compared to wildtype myofibers. Loss of myoferlin alone or together with a loss of dysferlin reduced sensitivity for EC coupling, and produced disorganized and smaller ryanodine receptor cluster size compared to wildtype myofibers. These data reveal impaired EC coupling in Myof and Fer myofibers and slightly potentiated EC coupling in Dysf myofibers. Despite high homology, dysferlin and myoferlin have differential roles in regulating sarcotubular formation and maintenance resulting in unique impairments in calcium handling properties.

Sign in / Sign up

Export Citation Format

Share Document