title: VIH2 Regulates the Synthesis of Inositol Pyrophosphate InsP8 and Jasmonate-Dependent Defenses in Arabidopsis.
abstract: Diphosphorylated inositol polyphosphates, also referred to as inositol pyrophosphates, are important signaling molecules that regulate critical cellular activities in many eukaryotic organisms, such as membrane trafficking, telomere maintenance, ribosome biogenesis, and apoptosis. In mammals and fungi, two distinct classes of inositol phosphate kinases mediate biosynthesis of inositol pyrophosphates: Kcs1/IP6K- and Vip1/PPIP5K-like proteins. Here, we report that PPIP5K homologs are widely distributed in plants and that Arabidopsis thaliana VIH1 and VIH2 are functional PPIP5K enzymes. We show a specific induction of inositol pyrophosphate InsP8 by jasmonate and demonstrate that steady state and jasmonate-induced pools of InsP8 in Arabidopsis seedlings depend on VIH2. We identify a role of VIH2 in regulating jasmonate perception and plant defenses against herbivorous insects and necrotrophic fungi. In silico docking experiments and radioligand binding-based reconstitution assays show high-affinity binding of inositol pyrophosphates to the F-box protein COI1-JAZ jasmonate coreceptor complex and suggest that coincidence detection of jasmonate and InsP8 by COI1-JAZ is a critical component in jasmonate-regulated defenses.
authors.affiliation: Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Debabrata
authors.identifier: http://orcid.org/0000-0002-7823-5489
authors.initials: D
authors.lastname: Laha
authors.affiliation: Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Philipp
authors.identifier: http://orcid.org/0000-0002-4512-9508
authors.initials: P
authors.lastname: Johnen
authors.affiliation: Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Cristina
authors.initials: C
authors.lastname: Azevedo
authors.affiliation: Zentrum für Datenverarbeitung, University of Tübingen, 72074 Tübingen, Germany.
authors.forename: Marek
authors.initials: M
authors.lastname: Dynowski
authors.affiliation: Department of Biology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Weiß
authors.affiliation: Department of Chemistry, University of Zürich, 8057 Zurich, Switzerland.
authors.forename: Samanta
authors.initials: S
authors.lastname: Capolicchio
authors.affiliation: Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195.
authors.forename: Haibin
authors.initials: H
authors.lastname: Mao
authors.affiliation: Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Iven
authors.affiliation: Plant-Microbe Interactions, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands.
authors.forename: Merel
authors.initials: M
authors.lastname: Steenbergen
authors.affiliation: Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Freyer
authors.affiliation: Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Gaugler
authors.affiliation: Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Marília K F
authors.initials: MK
authors.lastname: de Campos
authors.affiliation: Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195.
authors.forename: Ning
authors.initials: N
authors.lastname: Zheng
authors.affiliation: Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany.
authors.forename: Ivo
authors.initials: I
authors.lastname: Feussner
authors.affiliation: Department of Chemistry, University of Zürich, 8057 Zurich, Switzerland.
authors.forename: Henning J
authors.identifier: http://orcid.org/0000-0002-1025-9484
authors.initials: HJ
authors.lastname: Jessen
authors.affiliation: Plant-Microbe Interactions, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands.
authors.forename: Saskia C M
authors.initials: SC
authors.lastname: Van Wees
authors.affiliation: Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Adolfo
authors.initials: A
authors.lastname: Saiardi
authors.affiliation: Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany gabriel.schaaf@zmbp.uni-tuebingen.de.
authors.forename: Gabriel
authors.identifier: http://orcid.org/0000-0001-9022-4515
authors.initials: G
authors.lastname: Schaaf
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D007295:Inositol Phosphates / Q000378:metabolism*; D054883:Oxylipins / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D007295:Inositol Phosphates; D054883:Oxylipins; C011006:jasmonic acid