Regulation of calcium release by interdomain interaction within ryanodine receptors

10.2741/a803 ◽  
2002 ◽  
Vol 7 (4) ◽  
pp. d671-683 ◽  
Author(s):  
Noriaki Ikemoto
2011 ◽  
Vol 589 (24) ◽  
pp. 6063-6080 ◽  
Author(s):  
Beth A. Altschafl ◽  
Demetrios A. Arvanitis ◽  
Oscar Fuentes ◽  
Qunying Yuan ◽  
Evangelia G. Kranias ◽  
...  

2007 ◽  
Vol 293 (6) ◽  
pp. H3584-H3592 ◽  
Author(s):  
Nazmi Yaras ◽  
Erkan Tuncay ◽  
Nuhan Purali ◽  
Babur Sahinoglu ◽  
Guy Vassort ◽  
...  

The present study was designed to determine whether the properties of local Ca2+ release and its related regulatory mechanisms might provide insight into the role of sex differences in heart functions of control and streptozotocin-induced diabetic adult rats. Left ventricular developed pressure, the rates of pressure development and decay (±dP/d t), basal intracellular Ca2+ level ([Ca2+]i), and spatiotemporal parameters of [Ca2+]i transients were found to be similar in male and female control rats. However, spatiotemporal parameters of Ca2+ sparks in cardiomyocytes isolated from control females were significantly larger and slower than those in control males. Diabetes reduced left ventricular developed pressure to a lower extent in females than in males, and the diabetes-induced depressions in both +dP/d t and −dP/d t were less in females than in males. Diabetes elicited a smaller reduction in the amplitude of [Ca2+]i transients in females than in males, a smaller reduction in sarcoplasmic reticulum-Ca2+ load, and less increase in basal [Ca2+]i. Similarly, the elementary Ca2+ events and their control proteins were clearly different in both sexes, and these differences were more marked in diabetes. Diabetes-induced depression of the Ca2+ spark amplitude was significantly less in females than in matched males. Levels of cardiac ryanodine receptors (RyR2) and FK506-binding protein 12.6 in control females were significantly higher than those shown in control males. Diabetes induced less RyR2 phosphorylation and FK506-binding protein 12.6 unbinding in females. Moreover, total and free sulfhydryl groups were significantly less reduced, and PKC levels were less increased, in diabetic females than in diabetic males. The present data related to local Ca2+ release and its related proteins describe some of the mechanisms that may underlie sex-related differences accounting for females to have less frequent development of cardiac diseases.


2004 ◽  
Vol 380 (1) ◽  
pp. e1-e3 ◽  
Author(s):  
Tommie V. McCARTHY ◽  
John J. MACKRILL

Ryanodine receptors (RyRs) are a family of intracellular channels that mediate Ca2+ release from the endoplasmic and sarcoplasmic reticulum. More than 50 distinct point mutations in one member of this family, RyR1, cause malignant hyperthermia, a potentially lethal pharmacogenetic disorder of skeletal muscle. These mutations are not randomly distributed throughout the primary structure of RyR1, but are grouped in three discrete clusters. In this issue of the Biochemical Journal, Kobayashi et al. present evidence that interdomain interactions between two of these mutation-enriched regions play a key role in the gating mechanism of RyR1.


2005 ◽  
Vol 360 (1464) ◽  
pp. 2237-2246 ◽  
Author(s):  
Cecilia Hidalgo

Calcium release mediated by the ryanodine receptors (RyR) Ca 2+ release channels is required for muscle contraction and contributes to neuronal plasticity. In particular, Ca 2+ activation of RyR-mediated Ca 2+ release can amplify and propagate Ca 2+ signals initially generated by Ca 2+ entry into cells. Redox modulation of RyR function by a variety of non-physiological or endogenous redox molecules has been reported. The effects of RyR redox modification on Ca 2+ release in skeletal muscle as well as the activation of signalling cascades and transcription factors in neurons will be reviewed here. Specifically, the different effects of S -nitrosylation or S -glutathionylation of RyR cysteines by endogenous redox-active agents on the properties of skeletal muscle RyRs will be discussed. Results will be presented indicating that these cysteine modifications change the activity of skeletal muscle RyRs, modify their behaviour towards both activators and inhibitors and affect their interactions with FKBP12 and calmodulin. In the hippocampus, sequential activation of ERK1/2 and CREB is a requisite for Ca 2+ -dependent gene expression associated with long-lasting synaptic plasticity. The effects of reactive oxygen/nitrogen species on RyR channels from neurons and RyR-mediated sequential activation of neuronal ERK1/2 and CREB produced by hydrogen peroxide and other stimuli will be discussed as well.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Yuichi Toyama ◽  
Manabu Yonekura ◽  
Chong Han ◽  
Hirofumi Tomita ◽  
Hiroshi Takeshima ◽  
...  

Trimeric intracellular cation (TRIC) channels are expressed on the surface of sarcoplasmic reticulum (SR) and regulate calcium release from ryanodine receptors (RyRs). In a previous study, Tric-a knock out (KO) mice showed diminished calcium release from RyRs following increased calcium-influx via L-type calcium channels, which results in enhanced vascular resistance and non-dipper type hypertension. Decreased activation of RyR1 by PKA in skeletal myocytes in Tric-a KO mice is also known. However, physiological importance of TRIC channels on cardiac rhythm formation and its importance on the sympathetic nerve regulation are still obscure. Therefore, we aimed to clarify the effects of Tric-a ablation on cardiac pace making using Tric-a KO mice. We measured systolic blood pressure (SBP) with tail-cuff method, ECG and spontaneous action potential with microelectrode in the Tric-a KO and wild type (WT) mice. Isoproterenol or propranolol was used for sympathetic nerve manipulation. Furthermore, we evaluated heart rate variability (HRV). Tric-a KO mice tended to show limited responses to isoproterenol (0.3 mg/kg) than the WT mice (-27 ± 6 and -32 ± 6 mmHg, n = 10, p =0.70), and to propranolol (4 ± 6 and 13 ± 7 mmHg, n = 5~6, p =0.48). In ECG analysis, ablation of Tric-a gene resulted in significantly decreased heart rate changes to isoproterenol (23 ± 6 and 99 ± 15 bpm, Tric-a KO and WT mice, respectively, n = 9~10, p <0.001). Response to propranolol was also significantly decreased in the Tric-a KO mice (-28 ± 20 and -122 ± 14 bpm, Tric-a KO and WT mice, respectively, n = 9~10, p <0.001). In the action potential recordings, Tric-a KO mice showed significantly decreased sinus rate changes to 1 microM isoproterenol (35 ± 9 and 71 ± 10 bpm, Tric-a KO and WT mice, respectively, n = 6~8, p <0.05). In HRV analysis, low-frequency/high-frequency (LF/HF) ratio tended to be lower in the Tric-a KO mice than the WT mice under the administration of isoproterenol (0.22 ± 0.31 and 0.65 ± 0.16 bpm, Tric-a KO and WT mice, respectively, n = 9~11, p =0.16), suggesting lower sympathetic nerve tonus in the Tric-a KO mice. In conclusion, our data indicates that Tric-a KO mice showed attenuated responses to beta-adrenergic stimulus, which indicates involvement of TRIC-A channels in sympathetic nerve regulation.


1998 ◽  
Vol 4 (S2) ◽  
pp. 968-969
Author(s):  
Terry Wagenknecht ◽  
Montserrat Samso

Ryanodine receptors (RyRs) function as the major intracellular calcium release channels in striated muscle, where they also play a central role in excitation-contraction (e-c) coupling, the signal transduction process by which neuron-induced depolarization of the muscle plasma membrane leads to release of Ca from the sarcoplasmic reticulum. Structurally, RyRs are the largest ion channels known, being composed of 4 identical large subunits (565 kDa). In situ, RyRs interact with numerous proteins that are essential for e-c coupling or regulation thereof. Some of these ligands include calmodulin, a 12-kDa FK506-binding protein (FKBP, an immunophi1 in), calsequestrin, triadin, and the dihydropyridine receptor (DHPR).Detergent-solubilized, purified RyRs appear to retain their native structure as assessed by electron cryo-microscopy, and are amenable to three-dimensional reconstruction by single-particle image processing techniques. In Fig. 1, a solid-body representation of the reconstructed skeletal muscle RyR shows the structural complexity that is revealed at moderate resolutions (3-4 nm).


2007 ◽  
Vol 292 (5) ◽  
pp. C1960-C1970 ◽  
Author(s):  
Juan Antonio Valdés ◽  
Jorge Hidalgo ◽  
José Luis Galaz ◽  
Natalia Puentes ◽  
Mónica Silva ◽  
...  

Depolarization of skeletal muscle cells by either high external K+ or repetitive extracellular field potential pulses induces calcium release from internal stores. The two components of this release are mediated by either ryanodine receptors or inositol 1,4,5-trisphosphate (IP3) receptors and show differences in kinetics, amplitude, and subcellular localization. We have reported that the transcriptional regulators including ERKs, cAMP/Ca2+-response element binding protein, c- fos, c- jun, and egr-1 are activated by K+-induced depolarization and that their activation requires IP3-dependent calcium release. We presently describe the activation of the nuclear transcription factor NF-κB in response to depolarization by either high K+ (chronic) or electrical pulses (fluctuating). Calcium transients of relative short duration activate an NF-κB reporter gene to an intermediate level, whereas long-lasting calcium increases obtained by prolonged electrical stimulation protocols of various frequencies induce maximal activation of NF-κB. This activation is independent of extracellular calcium, whereas calcium release mediated by either ryanodine or IP3 receptors contribute in all conditions tested. NF-κB activation is mediated by IκBα degradation and p65 translocation to the nucleus. Partial blockade by N-acetyl-l-cysteine, a general antioxidant, suggests the participation of reactive oxygen species. Calcium-dependent signaling pathways such as those linked to calcineurin and PKC also contribute to NF-κB activation by depolarization, as assessed by blockade through pharmacological agents. These results suggest that NF-κB activation in skeletal muscle cells is linked to membrane depolarization and depends on the duration of elevated intracellular calcium. It can be regulated by sequential activation of calcium release mediated by the ryanodine and by IP3 receptors.


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