Structural insights into the regulatory mechanism Of IP3 receptor

Inositol 1,4,5-trisphosphate receptors (IP3R) are intracellular Ca2+ release channels whose opening requires binding of two intracellular messengers IP3 and Ca2+. The regulation of IP3R function has also been shown to involve a variety of cellular proteins. Recent biochemical and structural analyses have deepened our understanding of how the IP3-operated Ca2+ channel functions. Specifically, the atomic resolution structure of the IP3-binding region has provided a sound structural basis for the receptor interaction with the natural ligand. Electron microscopic studies have also shed light on the overall shape of the tetrameric receptor. This review aims to provide comprehensive overview of the current information available on the structure and function relationship of IP3R. (C) 2004 Elsevier B.V. All rights reserved.