Format

Send to

Choose Destination
Plant Cell. 2015 Apr;27(4):1082-97. doi: 10.1105/tpc.114.135160. Epub 2015 Apr 21.

VIH2 Regulates the Synthesis of Inositol Pyrophosphate InsP8 and Jasmonate-Dependent Defenses in Arabidopsis.

Author information

1
Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany.
2
Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom.
3
Zentrum für Datenverarbeitung, University of Tübingen, 72074 Tübingen, Germany.
4
Department of Biology, University of Tübingen, 72076 Tübingen, Germany.
5
Department of Chemistry, University of Zürich, 8057 Zurich, Switzerland.
6
Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195.
7
Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany.
8
Plant-Microbe Interactions, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands.
9
Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany gabriel.schaaf@zmbp.uni-tuebingen.de.

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.

PMID:
25901085
PMCID:
PMC4558690
DOI:
10.1105/tpc.114.135160
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center