title: Inositol pyrophosphates regulate JMJD2C-dependent histone demethylation.
abstract: Epigenetic modifications of chromatin represent a fundamental mechanism by which eukaryotic cells adapt their transcriptional response to developmental and environmental cues. Although an increasing number of molecules have been linked to epigenetic changes, the intracellular pathways that lead to their activation/repression have just begun to be characterized. Here, we demonstrate that inositol hexakisphosphate kinase 1 (IP6K1), the enzyme responsible for the synthesis of the high-energy inositol pyrophosphates (IP7), is associated with chromatin and interacts with Jumonji domain containing 2C (JMJD2C), a recently identified histone lysine demethylase. Reducing IP6K1 levels by RNAi or using mouse embryonic fibroblasts derived from ip6k1(-/-) knockout mice results in a decreased IP7 concentration that epigenetically translates to reduced levels of trimethyl-histone H3 lysine 9 (H3K9me3) and increased levels of acetyl-H3K9. Conversely, expression of IP6K1 induces JMJD2C dissociation from chromatin and increases H3K9me3 levels, which depend on IP6K1 catalytic activity. Importantly, these effects lead to changes in JMJD2C-target gene transcription. Our findings demonstrate that inositol pyrophosphate signaling influences nuclear functions by regulating histone modifications.
authors.affiliation: Medical Research Council Cell Biology Unit and Department of Cell and Developmental Biology, Medical Research Council Laboratory for Molecular Cell Biology, and Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Adam
authors.initials: A
authors.lastname: Burton
authors.forename: Cristina
authors.initials: C
authors.lastname: Azevedo
authors.forename: Catia
authors.initials: C
authors.lastname: Andreassi
authors.forename: Antonella
authors.initials: A
authors.lastname: Riccio
authors.forename: Adolfo
authors.initials: A
authors.lastname: Saiardi
mesh_terms: D000818:Animals; D002843:Chromatin / Q000502:physiology*; D011756:Diphosphates / Q000378:metabolism*; D044127:Epigenesis, Genetic / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006657:Histones / Q000378:metabolism*; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism*; D056484:Jumonji Domain-Containing Histone Demethylases / Q000378:metabolism*; D051379:Mice; D010766:Phosphorylation; D020798:Two-Hybrid System Techniques
chemical_list: D002843:Chromatin; D011756:Diphosphates; D006657:Histones; D007295:Inositol Phosphates; C413655:KDM4C protein, human; D056484:Jumonji Domain-Containing Histone Demethylases
keywords: inositides; metabolism; phosphorylation