title: Ryanodine receptor calcium release channels: an evolutionary perspective.
abstract: Ryanodine receptors (RyRs), along with the related inositol 1,4,5-trisphosphate receptors (IP(3)Rs), mediate the release of Ca(2+) from intracellular organelles of eukaryotes. As discussed in other chapters, such increases in intracellular Ca(2+) levels act a fundamental second messenger, regulating a diverse array of cellular processes. For over two decades, it has been reported that vertebrates express multiple RYR genes, whereas non-vertebrate multicellular organisms possess a single homologue within their genomes. Recently, the existence of RyR-like channels in unicellular organisms has also been reported. This chapter exploits recent expansions in available genome data to generate an overview of the expression of RyR-like genes in organisms representing a broad range of viral, archaeal, bacterial and eukaryotic taxa. Analyses of the multidomain structures and phylogenetic relationships of these proteins has lead to a model in which, early during eukaryotic evolution, IP(3)R-like ancestral Ca(2+) release channels were converted to RyR proteins via the addition of promiscuous protein domains, possibly via horizontal gene transfer mechanisms.
authors.affiliation: Department of Physiology, University College Cork, Western Gateway Building, Western Road, Cork, Ireland. j.mackrill@ucc.ie
authors.forename: John J
authors.initials: JJ
authors.lastname: Mackrill
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D006801:Humans; D017434:Protein Structure, Tertiary; D019837:Ryanodine Receptor Calcium Release Channel / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel; D002118:Calcium