Combined patch-clamp and fura-2 measurements were performed to study the calcium release properties of Chinese hamster ovary (CHO) cells transfected with the rabbit skeletal muscle ryanodine receptor cDNA carried by an expression vector. Both caffeine (1-50 mM) and ryanodine (100 microM) induced release of calcium from intracellular stores of transformed CHO cells but not from control (non-tran...

BACKGROUND FK506 binding protein is closely associated with the sarcoplasmic reticulum ryanodine receptor-channel and can modulate its function. The ryanodine receptor is stabilized by its association with FK506 binding protein. The immunosuppressant drugs FK506 (tacrolimus) and rapamycin can promote dissociation of FK506 binding protein from the ryanodine receptor 1 and by this mechanism incre...

Sphingosylphosphocholine (SPC) modulates Ca2+ release from isolated cardiac sarcoplasmic reticulum membranes; 50 microM SPC induces the release of 70 80% of the accumulated calcium. SPC release calcium from cardiac sarcoplasmic reticulum through the ryanodine receptor, since the release is inhibited by the ryanodine receptor channel antagonists ryanodine. Ruthenium Red and sphingosine. In intac...

INTRODUCTION WE REPORTED THAT RYANODINE RECEPTORS ARE EXPRESSED IN TWO DIFFERENT TYPES OF MAMMALIAN PERIPHERAL TASTE RECEPTOR CELLS: Type II and Type III cells. Type II cells lack voltage-gated calcium channels (VGCCs) and chemical synapses. In these cells, ryanodine receptors contribute to the taste-evoked calcium signals that are initiated by opening inositol trisphosphate receptors located o...

The skeletal muscle relaxant dantrolene inhibits the release of Ca from the sarcoplasmic reticulum during excitation-contraction coupling and suppresses the uncontrolled Ca release that underlies the skeletal muscle pharmacogenetic disorder malignant hyperthermia; however, the molecular mechanism by which dantrolene selectively affects skeletal muscle Ca regulation remains to be defined. Here w...

We have tested the periodate-oxidized ATP analogue 2',3'-dialdehyde adenosine triphosphate (oATP) as a ligand for the skeletal muscle ryanodine receptor/Ca(2+)-release channel. Ca2+ efflux from passively loaded heavy sarcoplasmic reticulum vesicles of skeletal muscle is biphasic. oATP stimulates the initial phase of Ca2+ release in a concentration-dependent manner (EC50 160 microM), and the eff...

The ryanodine receptor of rabbit skeletal muscle sarcoplasmic reticulum was purified as a single 450,000-dalton polypeptide from CHAPS-solubilized triads using immunoaffinity chromatography. The purified receptor had a [3H]ryanodine-binding capacity (Bmax) of 490 pmol/mg and a binding affinity (Kd) of 7.0 nM. Using planar bilayer recording techniques, we show that the purified receptor forms ca...

The family of ryanodine receptor (RyR) genes encodes three highly related Ca2+ release channels: RyR1, RyR2 and RyR3. Until about 10 years ago, RyRs were essentially known only for being the Ca2+ release channels of the sarcoplasmic reticulum of striated muscles, because of the high levels of expression of the RyR1 and RyR2 isoforms in skeletal and cardiac muscles, respectively. In contrast wit...

Using density gradient centrifugation and [3H]ryanodine as a specific marker, the ryanodine receptor-Ca2+ release channel complex from Chaps-solubilized canine cardiac sarcoplasmic reticulum (SR) has been purified in the form of an approximately 30 S complex, comprised of Mr approximately 400,000 polypeptides. Purification resulted in a specific activity of approximately 450 pmol bound ryanodin...