Intracellular Ca(2+) release channels in evolution.

Intracellular Ca(2+)-release channels (ICRCs) form a superfamily of genes that encompasses two distinct subfamilies: the inositol trisphosphate receptor and the ryanodine receptor genes, which encode the largest ion channels known today. During evolution from nematodes to man, mechanisms of gene duplication and divergence have increased the number of known ICRC genes, which have been gradually co-opted to contribute to the increasing complexity of intracellular Ca(2+) signalling required for regulation of specialised eukaryotic cell activities.