The Ryanodine Receptor/Calcium Release Channel and its Interaction Partners

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).

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Cryo-electron microscopy and three-dimensional reconstruction of the calcium release channel/ryanodine receptor from skeletal muscle.

The Journal of Cell Biology ◽

10.1083/jcb.127.2.411 ◽

1994 ◽

Vol 127 (2) ◽

pp. 411-423 ◽

Cited By ~ 190

Author(s):

M Radermacher ◽

V Rao ◽

R Grassucci ◽

J Frank ◽

A P Timerman ◽

...

Keyword(s):

Skeletal Muscle ◽

Calcium Release ◽

Structural Integrity ◽

Three Dimensional ◽

Calcium Release Channel ◽

Density Region ◽

Release Channel ◽

Dimensional Reconstruction ◽

Triad Junction ◽

Cytoplasmic Assembly

The calcium release channel (CRC) from skeletal muscle is an unusually large tetrameric ion channel of the sarcoplasmic reticulum, and it is a major component of the triad junction, the site of excitation contraction coupling. The three-dimensional architecture of the CRC was determined from a random conical tilt series of images extracted from electron micrographs of isolated detergent-solubilized channels prepared in a frozen-hydrated state. Three major classes of fourfold symmetric images were identified, and three-dimensional reconstructions were determined for two of these. The two independent reconstructions were almost identical, being related to each other by a 180 degrees rotation about an axis in the plane of the specimen grid. The CRC consists of a large cytoplasmic assembly (29 x 29 x 12 nm) and a smaller transmembrane assembly that protrudes 7 nm from one of its faces. A cylindrical low-density region, 2-3 nm in apparent diameter, extends down the center of the transmembrane assembly, and possibly corresponds to the transmembrane Ca(2+)-conducting pathway. At its cytoplasmic end this channel-like feature appears to be plugged by a globular mass of density. The cytoplasmic assembly is apparently constructed from 10 or more domains that are loosely packed together such that greater than 50% of the volume enveloped by the assembly is occupied by solvent. The cytoplasmic assembly is suggestive of a scaffolding and seems well adapted to maintain the structural integrity of the triad junction while allowing ions to freely diffuse to and away from the transmembrane assembly.

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Unravelling calcium-release channel gating: clues from a hot disease

Biochemical Journal ◽

10.1042/bj20040512 ◽

2004 ◽

Vol 380 (1) ◽

pp. e1-e3 ◽

Cited By ~ 1

Author(s):

Tommie V. McCARTHY ◽

John J. MACKRILL

Keyword(s):

Calcium Release ◽

Distinct Point ◽

Ryanodine Receptors ◽

Point Mutations ◽

Calcium Release Channel ◽

Release Channel ◽

Present Evidence ◽

Gating Mechanism ◽

Biochemical Journal ◽

Interdomain Interactions

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.

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Three-Dimensional Location of the Imperatoxin a Binding Site on the Ryanodine Receptor

The Journal of Cell Biology ◽

10.1083/jcb.146.2.493 ◽

1999 ◽

Vol 146 (2) ◽

pp. 493-500 ◽

Cited By ~ 49

Author(s):

Montserrat Samsó ◽

Ramon Trujillo ◽

Georgina B. Gurrola ◽

Hector H. Valdivia ◽

Terence Wagenknecht

Keyword(s):

Binding Site ◽

Ryanodine Receptor ◽

Calcium Release ◽

Particle Image ◽

Specific Binding ◽

Three Dimensional ◽

Calcium Release Channel ◽

Release Channel ◽

Cryo Electron Microscopy ◽

Peptide Toxin

Cryo-electron microscopy and three-dimensional, single-particle image analysis have been used to reveal the specific binding site of imperatoxin A (IpTxa) on the architecture of the calcium release channel/ryanodine receptor from skeletal muscle (RyR1). IpTxa is a peptide toxin that binds with high affinity to RyR1 and affects its functioning. The toxin was derivatized with biotin to enhance its detection with streptavidin. IpTxa binds to the cytoplasmic moiety of RyR1 between the clamp and handle domains, 11 nm away from the transmembrane pore. The proposed mimicry by IpTxa of the dihydropyridine receptor (DHPR) II-III loop, thought to be a main physiological excitation-contraction trigger, suggests that the IpTxa binding location is a potential excitation-contraction signal transduction site.

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Type 3 and Type 1 Ryanodine Receptors Are Localized in Triads of the Same Mammalian Skeletal Muscle Fibers

The Journal of Cell Biology ◽

10.1083/jcb.146.3.621 ◽

1999 ◽

Vol 146 (3) ◽

pp. 621-630 ◽

Cited By ~ 52

Author(s):

Bernhard E. Flucher ◽

Antonio Conti ◽

Hiroshi Takeshima ◽

Vincenzo Sorrentino

Keyword(s):

Skeletal Muscle ◽

Calcium Release ◽

Ryanodine Receptors ◽

Physiological Role ◽

Fiber Types ◽

Mammalian Skeletal Muscle ◽

Calcium Release Channel ◽

Release Channel ◽

Accessory Function ◽

Type 3

The type 3 ryanodine receptor (RyR3) is a ubiquitous calcium release channel that has recently been found in mammalian skeletal muscles. However, in contrast to the skeletal muscle isoform (RyR1), neither the subcellular distribution nor the physiological role of RyR3 are known. Here, we used isoform-specific antibodies to localize RyR3 in muscles of normal and RyR knockout mice. In normal hind limb and diaphragm muscles of young mice, RyR3 was expressed in all fibers where it was codistributed with RyR1 and with the skeletal muscle dihydropyridine receptor. This distribution pattern indicates that RyR3 is localized in the triadic junctions between the transverse tubules and the sarcoplasmic reticulum. During development, RyR3 expression declined rapidly in some fibers whereas other fibers maintained expression of RyR3 into adulthood. Comparing the distribution of RyR3-containing fibers with that of known fiber types did not show a direct correlation. Targeted deletion of the RyR1 or RyR3 gene resulted in the expected loss of the targeted isoform, but had no adverse effects on the expression and localization of the respective other RyR isoform. The localization of RyR3 in skeletal muscle triads, together with RyR1, is consistent with an accessory function of RyR3 in skeletal muscle excitation–contraction coupling.

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PKA phosphorylation activates the calcium release channel (ryanodine receptor) in skeletal muscle

The Journal of Cell Biology ◽

10.1083/jcb.200211012 ◽

2003 ◽

Vol 160 (6) ◽

pp. 919-928 ◽

Cited By ~ 159

Author(s):

Steven Reiken ◽

Alain Lacampagne ◽

Hua Zhou ◽

Aftab Kherani ◽

Stephan E. Lehnart ◽

...

Keyword(s):

Skeletal Muscle ◽

Ryanodine Receptor ◽

Calcium Release ◽

Calcium Release Channel ◽

Skeletal Muscle Function ◽

Release Channel ◽

Fk506 Binding Protein ◽

Ec Coupling ◽

Increased Activity

The type 1 ryanodine receptor (RyR1) on the sarcoplasmic reticulum (SR) is the major calcium (Ca2+) release channel required for skeletal muscle excitation–contraction (EC) coupling. RyR1 function is modulated by proteins that bind to its large cytoplasmic scaffold domain, including the FK506 binding protein (FKBP12) and PKA. PKA is activated during sympathetic nervous system (SNS) stimulation. We show that PKA phosphorylation of RyR1 at Ser2843 activates the channel by releasing FKBP12. When FKB12 is bound to RyR1, it inhibits the channel by stabilizing its closed state. RyR1 in skeletal muscle from animals with heart failure (HF), a chronic hyperadrenergic state, were PKA hyperphosphorylated, depleted of FKBP12, and exhibited increased activity, suggesting that the channels are “leaky.” RyR1 PKA hyperphosphorylation correlated with impaired SR Ca2+ release and early fatigue in HF skeletal muscle. These findings identify a novel mechanism that regulates RyR1 function via PKA phosphorylation in response to SNS stimulation. PKA hyperphosphorylation of RyR1 may contribute to impaired skeletal muscle function in HF, suggesting that a generalized EC coupling myopathy may play a role in HF.

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Amplifying long transcripts of ryanodine receptors of five agricultural pests by transcriptome analysis and gap filling

Genome ◽

10.1139/gen-2013-0127 ◽

2013 ◽

Vol 56 (11) ◽

pp. 651-658 ◽

Cited By ~ 5

Author(s):

Yonglei Liu ◽

Muhammad Faisal Shahzad ◽

Lan Zhang ◽

Fei Li ◽

Kejian Lin

Keyword(s):

Calcium Release ◽

Ryanodine Receptors ◽

Resistance Mechanism ◽

Full Length ◽

Cnaphalocrocis Medinalis ◽

Agricultural Pests ◽

Calcium Release Channel ◽

Release Channel ◽

Rapid Amplification ◽

Molecular Manipulation

Ryanodine receptor (RyR) is an intracellular calcium release channel that plays a key role in excitation contraction coupling. Insect RyR is the target of diamide insecticides. Better understanding of insect RyR is necessary for studying the molecular mode of action and potential resistance mechanism of diamide insecticides. However, molecular manipulation of the full RyR gene is difficult because of its length (approximately 15 kb). At present, RyR genes have been reported only in a limited number of insects. Here, we developed an efficient strategy to amplify full-length transcripts of insect RyR genes. First, we searched the transcriptomes of five insects, Bemisia tabaci, Cnaphalocrocis medinalis, Chilo suppressalis, Laodelphgax striatellus, and Plutella xylostella, yielding 85 RyR contigs in total. Second, the relative positions of these contigs in RyR transcripts were determined by aligning them with 12 well-annotated RyRs. Third, we designed primers to fill gaps between contigs and used rapid amplification of cDNA ends (RACE) to amplify both 5′- and 3′-ends. Last, we assembled all fragments into long transcripts. As a result, full-length transcripts of three insects, C. suppressalis, L. striatellus, and P. xylostella, were obtained. The RyR transcript of B. tabaci was near full length, containing an intact ORF. Northern blot analysis indicated that RyR genes were expressed in all five insects. Sequence analyses showed that the amplified insect segments contained typical RyRs characteristics, such as EF-hand, motif GVRAGGGIGD, and six transmembrane domains. Seven lepidopteran-specific amino acid residues were found to be located in the C-terminal region of RyR proteins, which might be associated with the specificity of RyRs to diamide insecticides.

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FK506 binding protein associated with the calcium release channel (ryanodine receptor).

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)50114-4 ◽

1992 ◽

Vol 267 (14) ◽

pp. 9474-9477

Author(s):

T Jayaraman ◽

A.M. Brillantes ◽

A.P. Timerman ◽

S Fleischer ◽

H Erdjument-Bromage ◽

...

Keyword(s):

Ryanodine Receptor ◽

Calcium Release ◽

Binding Protein ◽

Calcium Release Channel ◽

Release Channel ◽

Fk506 Binding Protein

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Location of Divergent Region 2 on the Three-dimensional Structure of Cardiac Muscle Ryanodine Receptor/Calcium Release Channel

Journal of Molecular Biology ◽

10.1016/j.jmb.2004.03.011 ◽

2004 ◽

Vol 338 (3) ◽

pp. 533-545 ◽

Cited By ~ 44

Author(s):

Zheng Liu ◽

Jing Zhang ◽

Ruiwu Wang ◽

S.R. Wayne Chen ◽

Terence Wagenknecht

Keyword(s):

Cardiac Muscle ◽

Ryanodine Receptor ◽

Calcium Release ◽

Three Dimensional ◽

Dimensional Structure ◽

Calcium Release Channel ◽

Release Channel ◽

Three Dimensional Structure ◽

Divergent Region

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Cellular functions of immunophilins

Physiological Reviews ◽

10.1152/physrev.1996.76.3.631 ◽

1996 ◽

Vol 76 (3) ◽

pp. 631-649 ◽

Cited By ~ 266

Author(s):

A. R. Marks

Keyword(s):

Calcium Release ◽

Ryanodine Receptors ◽

Cellular Functions ◽

Prolyl Isomerase ◽

Calcium Release Channel ◽

Release Channel ◽

Isomerase Activity ◽

Channel Function ◽

Enzymatic Function ◽

Peptidyl Prolyl Isomerases

Immunophilins are members of a highly conserved family of proteins all of which are cis-trans peptidyl-prolyl isomerases. The prototypic members of the immunophilin family, cyclophilin A and FKPB12, were discovered on the basis of their ability to bind and mediate the immunosuppressive effects of the drugs cyclosporin, FK506, and rapamycin. However, the prolyl isomerase activity of these proteins is not involved in any of the immunosuppressive effects. Indeed, despite the fact that all members of the family are prolyl isomerases, the cellular role of this enzymatic function has not been clearly defined. In many cases, immunophilins are widely expressed and are present at high levels in some tissues. Moreover, while the number of proteins that belong to the immunophilin family continues to grow, the natural cellular functions of all but a few remain obscure. An example where immunophilins do appear to have a defined cellular role, in the absence of immunosuppressive ligands, is the modulation of intracellular calcium release channel function by FKBP12 and FKBP12.6. In this case, FKBPs are integral parts of three types of calcium release channel complexes, skeletal and cardiac ryanodine receptors and the inositol 1,4,5-trisphosphate receptor. In each case, FKBPs modulate channel function possibly by enhancing the cooperativity between subunits.

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