PathwayStep1190 PathwayStep1179 PathwayStep1167 PathwayStep1174 PathwayStep1177 PathwayStep1171 PathwayStep1163 PathwayStep1160 PathwayStep1124 PathwayStep1128 PathwayStep1144 PathwayStep1139 IPs transport between ER lumen and cytosol Synthesis of IP2, IP, and Ins in the cytosol IPs transport between nucleus and ER lumen IPs transport between ER lumen and nucleus Synthesis of IPs in the ER lumen IPs transport between cytosol and ER lumen IPs transport between nucleus and cytosol Synthesis of IPs in the nucleus IP6 and IP7 transport between cytosol and nucleus Synthesis of pyrophosphates in the cytosol Inositol phosphate metabolism Authored: Williams, MG, 2011-10-28 Edited: Williams, MG, 2011-10-28 GENE ONTOLOGYGO:0043647 Inositol phosphates (IPs) are molecules involves in signalling processes in eukaryotes. myo-Inositol consists of a six-carbon cyclic alcohol with an axial 2-hydroxy and five equatorial hydroxyls. Mono-, di-, and triphosphorylation of the inositol ring generates a wide variety of stereochemically distinct signalling entities. Inositol 1,4,5-trisphosphate (I(1,4,5)P3), is formed when the phosphoinositide phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) is hydrolysed by a phospholipase C isozyme. An array of inositol trisphosphate (IP3) and tetrakisphosphate (IP4) molecules are synthesised by the action of various kinases and phosphatases in the cytosol. These species then transport between the cytosol and the nucleus where they are acted on by inositol polyphosphate multikinase (IPMK), inositol-pentakisphosphate 2-kinase (IPPK), inositol hexakisphosphate kinase 1 (IP6K1) and 2 (IP6K2), to produce IP5, IP6, IP7, and IP8 molecules. Some of these nuclear produced IPs transport back to the cytosol where they are converted to an even wider variety of IPs, by kinases and phosphatases, including the di- and triphospho inositol phosphates aka pyrophosphates (Irvine & Schell 2001, Bunney & Katan 2010, Alcazar-Romain & Wente 2008, York 2006, Monserrate and York 2010). Pubmed11331907 Pubmed16781889 Pubmed17943301 Pubmed20359876 Pubmed20414202 Reactome Database ID Release 431483249 Reactome, http://www.reactome.org ReactomeREACT_150154 Reviewed: Challiss, John, 2012-11-09 Reviewed: Wundenberg, Torsten, 2012-11-06 IP3 and IP4 transport between cytosol and nucleus Synthesis of IP3 and IP4 in the cytosol