<p>Ryanodine receptors are involved in communication between transverse-tubulesand the sarcoplamic reticulum of cardiac and skeletal muscle. The proteinsfunction as a Ca²⁺-release channels following depolarisation of transverse-tubules [<cite idref="PUB00002638"/>]. The function is modulated by Ca²⁺, Mg2+, ATP and calmodulin.Deficiency in the ryanodine receptor may be the cause of malignanthyperthermia (MH) and of central core disease of muscle (CCD) [<cite idref="PUB00001957"/>]. MH isan autosomal dominant disorder of skeletal muscle and is a principalcause of death due to anaesthesia.</p><p>Calcium release activity of the receptors resides in the C-terminal regionof the protein, the remaining part of the molecule forming a 'foot'structure that spans the junctional gap between the sarcoplamic reticulumand the transverse-tubule. The foot structure may interact with thecytoplasmic region of the dihydropyridine receptor.</p><p>Analysis of the sequence reveals 10 potential transmembrane (TM) regionsin the C-terminal fifth of the molecule and 2 further potential TM regionsnearer to the centre [<cite idref="PUB00002597"/>]. These may contribute to the formation of the Ca²⁺conducting pore. The rest of the sequence is hydrophilic, and presumablyconstitutes the cytoplasmic domain of the protein.</p> Ryanodine receptor