[Structure and pharmacology of ryanodine receptors]

Ryanodine receptors (RyR) exist at the membrane of the intracellular calcium stores and function as the calcium-release channels in the vertebrate animal cells. In the mammalian animals three isoforms of RyR, skeletal type (RyR1), cardiac type (RyR2) and brain type (RyR3), have been identified, and they are encoded by three distinct genes, ryr1, ryr2 and ryr3, respectively. Meanwhile, in the non-mammalian vertebrate animals other three isoforms of RyR have been found: alpha RyR and beta RyR present in the skeletal muscle simultaneously, whose amino acid sequences exhibit the high identity to that of the mammalian RyR1 and RyR3 respectively, and another distinct isoform of RyR in the avian heart. In addition, a large variety of cells of both mammalian and non-mammalian vertebrate animal expresses all or two of the three isoforms of RyR simultaneously. Molecular structure and pharmacology of these isoforms of RyR are reviewed in this article.