Posts Tagged: ryanodine receptor calcium release channel

Calcium Signaling and Cardiac Arrhythmias

Calcium Signaling and Cardiac Arrhythmias

Andrew P. Landstrom, Dobromir Dobrev, Xander H.T. Wehrens

Ryanodine receptor type-2 (RyR2) macromolecular complex. Cartoon representing RyR2 pore-forming subunits with accessory proteins that bind to and/or modulate channel function. CaM indicates calmodulin; CaMKII, Ca2+/calmodulin-dependent protein kinase II; CASQ2, calsequestrin-2; FKBP12.6, FK506-binding protein-12.6; JCTN, junctin; JPH2, juncophilin-2; PKA, protein kinase A; PM, plasma membrane; PP, protein phosphatase; SR, sarcoplasmic reticulum; TECRL, trans-2,3-enoyl-CoA reductase-like protein; and TRDN; triadin. [Powerpoint File]

Calcium Signaling and Cardiac Arrhythmias

Calcium Signaling and Cardiac Arrhythmias

Andrew P. Landstrom, Dobromir Dobrev, Xander H.T. Wehrens

Role of calcium-handling in excitation–contraction (EC) coupling. A, Schematic overview of key Ca2+-handling proteins involved in EC coupling. B, Schematic diagram of Ca2+ release unit and major components of the JMC (junctional membrane complex). The transverse tubule (TT) and sarcoplasmic reticulum (SR) membranes approximate to form the dyad. BIN1 indicates bridging integrator 1; Cav1.2, L-type Ca2+ channel; CAV3, caveolin-3; JPH2, juncophilin-2; NCX1, Na+/Ca2+ exchanger type-1; PM, plasma membrane; PMCA, plasmalemmal Ca2+-ATPase; RyR2, ryanodine receptor type-2; and SERCA2a, sarco/endoplasmic reticulum ATPase type-2a.* [Powerpoint File]

Calcium and Excitation-Contraction Coupling in the Heart

Calcium and Excitation-Contraction Coupling in the Heart

David A. Eisner, Jessica L. Caldwell, Kornél Kistamás, Andrew W. Trafford

Structures involved in Ca cycling. A, Schematic diagram. This shows surface membrane, transverse tubule, sarcoplasmic reticulum (SR), and mitochondria, as well as the various channels and transporters mentioned in the text. B, High-resolution transverse section of a ventricular myocyte showing t-tubule network. Reprinted from Jayasinghe et al39 with permission of the publisher. Copyright ©2009, Biophysical Society. C, Cartoon of dyad emphasizing the major proteins involved in Ca cycling. B-AR indicates beta adrenoceptor; MCU, mitochondrial Ca uniporter; NCX, sodium–calcium exchange; NCLX, mitochondrial Na–Ca exchange; PMCA, plasma membrane Ca-ATPase; RyR, ryanodine receptor; and SERCA, sarco/endoplasmic reticulum Ca-ATPase. [Powerpoint File]

Trimeric Intracellular Cation Channels and Sarcoplasmic/Endoplasmic Reticulum Calcium Homeostasis

Trimeric Intracellular Cation Channels and Sarcoplasmic/Endoplasmic Reticulum Calcium Homeostasis

Xinyu Zhou, Peihui Lin, Daiju Yamazaki, Ki Ho Park, Shinji Komazaki, S.R. Wayne Chen, Hiroshi Takeshima, Jianjie Ma

Model for trimeric intracellular cation channels (TRIC) function in Ca2+ signaling. A, TRIC-A and TRIC-B are 2 isoforms of the trimeric intracellular cation channels. Both TRIC-A and TRIC-B channels can conduct monovalent cations to provide the flow of counter currents associated with release of Ca2+ ions from intracellular stores. TRIC-A modulates ryanodine receptor (RyR)–mediated Ca2+ release from the sarcoplasmic reticulum (SR), and TRIC-B facilitates IP3 receptor (IP3R)–mediated Ca2+ release from the endoplasmic reticulum (ER). Whether there is a cross-talk between TRIC-A– and TRIC-B–mediated intracellular Ca2+ signaling remains to be explored. Molecular identify of other channels located on the ER/SR membranes are not known. B, Topology model of TRIC channels on the SR/ER membrane. SERCA indicates sarco/endoplasmic reticulum ATPase. (Illustration Credit: Ben Smith.) [Powerpoint File]

Regulation of Ion Channels by Pyridine Nucleotides

Regulation of Ion Channels by Pyridine Nucleotides

Peter J. Kilfoil, Srinivas M. Tipparaju, Oleg A. Barski, Aruni Bhatnagar

Structure of the Slo channels and their regulation by pyridine nucleotides. Organization of the structural subunits of Slo1 (A) and Slo 2 family of channels (B). Adapted with permission from Nat Rev Neurosci, Salkoff et al.13 C, Inside-out patch-clamp recordings from pulmonary artery smooth muscle cells; horizontal bars represent application of 2 mmol/L NADH or NAD+. Current was recorded with a holding potential of +50 mV. Reprinted with permission from Exp Physiol, Park et al130; D, Inside-out patch-clamp recordings from rat dorsal root ganglion neurons in the absence and presence of 1 mmol/L NAD+ made from a holding potential of −80 mV. Adapted with permission from J Neurosci, Tamsett et al12 (Illustration: Ben Smith). [Powerpoint File]