LIGAND-GATED CALCIUM CHANNELS INSIDE AND OUT

Calcium release from intracellular stores occurs through two types of channels associated with intracellular membranes, namely, the ryanodin e receptor and the inositol 1,4,5-trisphosphate receptor. Recently, it has been shown that these channels are regulated by allosteric mechan isms and associated proteins. Release of intracellular calcium induces the opening of calcium-permeable channels on the plasma membrane. Cur rent work has focused on the molecular and functional characterization of these channels which have been identified as store-operated channe ls or calcium release activated channels.