SnRK1-triggered switch of bZIP63 dimerization mediates the low-energy response in plants

Andrea Mair, Lorenzo Pedrotti, Bernhard Wurzinger, Dorothea Anrather, Andrea Simeunovic, Christoph Weiste, Concetta Valerio, Katrin Dietrich, Tobias Kirchler, Thomas Nägele, Jesús Vicente Carbajosa, Johannes Hanson, Elena Baena-González, Christina Chaban, Wolfram Weckwerth, Wolfgang Dröge-Laser, Markus Teige

Metabolic adjustment to changing environmental conditions, particularly balancing of growth and defense responses, is crucial for all organisms to survive. The evolutionary conserved AMPK/Snf1/SnRK1 kinases are well-known metabolic master regulators in the low-energy response in animals, yeast and plants. They act at two different levels: by modulating the activity of key metabolic enzymes, and by massive transcriptional reprogramming. While the first part is well established, the latter function is only partially understood in animals and not at all in plants. Here we identified the Arabidopsis transcription factor bZIP63 as key regulator of the starvation response and direct target of the SnRK1 kinase. Phosphorylation of bZIP63 by SnRK1 changed its dimerization preference, thereby affecting target gene expression and ultimately primary metabolism. A bzip63 knock-out mutant exhibited starvation-related phenotypes, which could be functionally complemented by wild type bZIP63, but not by a version harboring point mutations in the identified SnRK1 target sites.

Department of Biochemistry and Cell Biology, Large-Instrument Facility for Mass Spectrometry in Life Sciences
External organisation(s)
Julius-Maximilians-Universität Würzburg, Instituto Gulbenkian de Ciência, Eberhard Karls Universität Tübingen, Universidad Politécnica de Madrid, Utrecht University, Umeå University, Universität für Bodenkultur Wien
Publication date
Peer reviewed
Austrian Fields of Science 2012
106023 Molecular biology, 106044 Systems biology
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