CTR1 phosphorylates the central regulator EIN2 to control ethylene hormone signaling from the ER membrane to the nucleus in Arabidopsis
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- 6 November 2012
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 109 (47), 19486-19491
- https://doi.org/10.1073/pnas.1214848109
Abstract
The gaseous phytohormone ethylene C2H4 mediates numerous aspects of growth and development. Genetic analysis has identified a number of critical elements in ethylene signaling, but how these elements interact biochemically to transduce the signal from the ethylene receptor complex at the endoplasmic reticulum (ER) membrane to transcription factors in the nucleus is unknown. To close this gap in our understanding of the ethylene signaling pathway, the challenge has been to identify the target of the CONSTITUTIVE TRIPLE RESPONSE1 (CTR1) Raf-like protein kinase, as well as the molecular events surrounding ETHYLENE-INSENSITIVE2 (EIN2), an ER membrane-localized Nramp homolog that positively regulates ethylene responses. Here we demonstrate that CTR1 interacts with and directly phosphorylates the cytosolic C-terminal domain of EIN2. Mutations that block the EIN2 phosphorylation sites result in constitutive nuclear localization of the EIN2 C terminus, concomitant with constitutive activation of ethylene responses in Arabidopsis. Our results suggest that phosphorylation of EIN2 by CTR1 prevents EIN2 from signaling in the absence of ethylene, whereas inhibition of CTR1 upon ethylene perception is a signal for cleavage and nuclear localization of the EIN2 C terminus, allowing the ethylene signal to reach the downstream transcription factors. These findings significantly advance our understanding of the mechanisms underlying ethylene signal transduction.Keywords
This publication has 44 references indexed in Scilit:
- Protein Kinase Domain of CTR1 from Arabidopsis thaliana Promotes Ethylene Receptor Cross TalkJournal of Molecular Biology, 2012
- Proteomic responses in Arabidopsis thaliana seedlings treated with ethyleneMolecular BioSystems, 2011
- Confident Phosphorylation Site Localization Using the Mascot Delta ScoreMolecular & Cellular Proteomics, 2011
- Molecular Association of the Arabidopsis ETR1 Ethylene Receptor and a Regulator of Ethylene Signaling, RTE1Journal of Biological Chemistry, 2010
- Gas-Phase Rearrangements Do Not Affect Site Localization Reliability in Phosphoproteomics Data SetsJournal of Proteome Research, 2010
- EIN2, the central regulator of ethylene signalling, is localized at the ER membrane where it interacts with the ethylene receptor ETR1Biochemical Journal, 2009
- Dual control of nuclear EIN3 by bifurcate MAPK cascades in C2H4 signallingNature, 2008
- Localization of the Raf-like Kinase CTR1 to the Endoplasmic Reticulum of Arabidopsis through Participation in Ethylene Receptor Signaling ComplexesJournal of Biological Chemistry, 2003
- Sterol-Regulated Release of SREBP-2 from Cell Membranes Requires Two Sequential Cleavages, One Within a Transmembrane SegmentCell, 1996
- CTR1, a negative regulator of the ethylene response pathway in arabidopsis, encodes a member of the Raf family of protein kinasesCell, 1993