Structural insights into endoplasmic reticulum stored calcium regulation by inositol 1,4,5-trisphosphate and ryanodine receptors

The two major calcium (Ca2+) release channels on the sarco/endoplasmic reticulum (SR/ER) are inositol 1,4,5-trisphosphate and ryanodine receptors (IP(3)Rs and RyRs). They play versatile roles in essential cell signaling processes, and abnormalities of these channels are associated with a variety of diseases. Structural information on IP3Rs and RyRs determined using multiple techniques including X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy and cryo-electron microscopy (EM), has significantly advanced our understanding of the mechanisms by which these Ca2+ release channels function under normal and pathophysiological circumstances. In this review, structural advances on the understanding of the mechanisms of IP3R and RyR function and dysfunction are summarized. This article is part of a Special Issue entitled: 13th European Symposium on Calcium. (C) 2014 Elsevier B.V. All rights reserved.