title: Interplay between phosphorylation and SUMOylation events determines CESTA protein fate in brassinosteroid signalling.
abstract: Brassinosteroids (BRs) are steroid hormones that are essential for plant growth. Responses to these hormones are mediated by transcription factors of the bri1-EMS suppressor 1/brassinazole resistant 1 subfamily, and BRs activate these factors by impairing their inhibitory phosphorylation by GSK3/shaggy-like kinases. Here we show that BRs induce nuclear compartmentalization of CESTA (CES), a basic helix-loop-helix transcription factor that regulates BR responses, and reveal that this process is regulated by CES SUMOylation. We demonstrate that CES contains an extended SUMOylation motif, and that SUMOylation of this motif is antagonized by phosphorylation to control CES subnuclear localization. Moreover, we provide evidence that phosphorylation regulates CES transcriptional activity and protein turnover by the proteasome. A coordinated modification model is proposed in which, in a BR-deficient situation, CES is phosphorylated to activate target gene transcription and enable further posttranslational modification that controls CES protein stability and nuclear dynamics.
authors.affiliation: 1] Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany [2] Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria.
authors.forename: Mamoona
authors.initials: M
authors.lastname: Khan
authors.affiliation: 1] Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany [2] Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Rozhon
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Simon Josef
authors.initials: SJ
authors.lastname: Unterholzner
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Tingting
authors.initials: T
authors.lastname: Chen
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Marina
authors.initials: M
authors.lastname: Eremina
authors.affiliation: Department of Molecular Systems Biology, University of Vienna, A-1090 Vienna, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Wurzinger
authors.affiliation: Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bachmair
authors.affiliation: Department of Molecular Systems Biology, University of Vienna, A-1090 Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Teige
authors.affiliation: Plant Growth Regulation, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Sieberer
authors.affiliation: Plant Systems Biology, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Erika
authors.initials: E
authors.lastname: Isono
authors.affiliation: 1] Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany [2] Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Poppenberger
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000502:physiology*; D060406:Brassinosteroids; D018257:Helix-Loop-Helix Motifs / Q000502:physiology; D008954:Models, Biological; D010766:Phosphorylation / Q000502:physiology; D010937:Plant Growth Regulators / Q000502:physiology; D011499:Protein Processing, Post-Translational / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D058207:Sumoylation / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D010937:Plant Growth Regulators; D014157:Transcription Factors