Ryanodine receptor

Ryanodine receptors are a family of calcium ion channels, whose activation causes the release of calcium ions from the sarcoplasmic reticulum into the cytosol. Thus, they play a role in triggering muscle contraction TION. Your name relate ryanodine receptors by ryanodine alkaloid, originally extracted from the plant Ryania speciosa ( Salicaceae ). Ryanodine ryanodine receptor which selectively binds to and blocks.

Subtypes

There are three subtypes of ryanodine receptors:

• RYR1 is expressed primarily in skeletal muscle, but also occurs in the Purkinje cells of the cerebellum. In the striated muscle RYR1 is in direct connection with the dihydropyridine receptors in the membrane of the transverse tubules. In one triggered by the action potential of the muscle conformation of the L- type calcium channels also open the RYR1 channels. In this way, it comes to the initial release of calcium ions from the sarcoplasmic reticulum into the cytosol of muscle cell. Therefore plays a key role in the RYR1 electromechanical coupling. Mutations in the RYR1 gene are observed in the central core myopathy and multicore myopathy. They represent an essential disposition for the development of malignant hyperthermia and are inhibited by dantrolene, which also accounts for the therapy that very disease.
• RYR2 is expressed in cardiac muscle. Mutation of this receptor subtype cause catecholaminergic polymorphic ventricular tachycardia, an autosomal dominantly inherited form of ventricular tachycardia, which is associated with abnormal widening of the QRS complex in the ECG and that can lead to syncope and sudden cardiac death.
• RYR3 is expressed during fetal development and in the neonatal period in skeletal muscle, however, remains essentially limited to the brain in adults. Here, this subtype may be involved in learning tasks.