Structural basis for oligomerization of auxin transcriptional regulators.
The plant hormone auxin is a key morphogenetic regulator acting from embryogenesis onwards. Transcriptional events in response to auxin are mediated by the auxin response factor (ARF) transcription factors and the Aux/IAA (IAA) transcriptional repressors. At low auxin concentrations, IAA repressors associate with ARF proteins and recruit corepressors that prevent auxin-induced gene expression. At higher auxin concentrations, IAAs are degraded and ARFs become free to regulate auxin-responsive genes. The interaction between ARFs and IAAs is thus central to auxin signalling and occurs through the highly conserved domain III/IV present in both types of proteins. Here, we report the crystal structure of ARF5 domain III/IV and reveal the molecular determinants of ARF-IAA interactions. We further provide evidence that ARFs have the potential to oligomerize, a property that could be important for gene regulation in response to auxin.
1] European Molecular Biology Laboratory, 6 rue Jules Horowitz, BP 181, Grenoble 38042, France [2] Unit of Virus Host-Cell Interactions, UJF-EMBL-CNRS, UMI 3265, 6 rue Jules Horowitz, Grenoble Cedex 9 38042, France.
Max H
MH
Nanao
1] CNRS, Laboratoire de Physiologie Cellulaire and Végétale, UMR 5168, Grenoble 38054, France [2] Univ. Grenoble Alpes, LPCV, Grenoble F-38054, France [3] CEA, DSV, iRTSV, LPCV, Grenoble F-38054, France [4] INRA, LPCV, Grenoble F-38054, France [5].
Thomas
T
Vinos-Poyo
1] Laboratoire de Reproduction et Développement des Plantes, CNRS, INRA, ENS Lyon, UCBL, Université de Lyon, Lyon 69364, France [2].
Géraldine
G
Brunoud
1] CNRS, Laboratoire de Physiologie Cellulaire and Végétale, UMR 5168, Grenoble 38054, France [2] Univ. Grenoble Alpes, LPCV, Grenoble F-38054, France [3] CEA, DSV, iRTSV, LPCV, Grenoble F-38054, France [4] INRA, LPCV, Grenoble F-38054, France [5].
Emmanuel
E
Thévenon
1] CNRS, Laboratoire de Physiologie Cellulaire and Végétale, UMR 5168, Grenoble 38054, France [2] Univ. Grenoble Alpes, LPCV, Grenoble F-38054, France [3] CEA, DSV, iRTSV, LPCV, Grenoble F-38054, France [4] INRA, LPCV, Grenoble F-38054, France.
Meryl
M
Mazzoleni
Laboratoire de Reproduction et Développement des Plantes, CNRS, INRA, ENS Lyon, UCBL, Université de Lyon, Lyon 69364, France.
David
D
Mast
Laboratoire de Reproduction et Développement des Plantes, CNRS, INRA, ENS Lyon, UCBL, Université de Lyon, Lyon 69364, France.
Stéphanie
S
Lainé
Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China.
Shucai
S
Wang
Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA.
Gretchen
G
Hagen
Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA.
Hanbing
H
Li
Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, USA.
Thomas J
TJ
Guilfoyle
1] CNRS, Laboratoire de Physiologie Cellulaire and Végétale, UMR 5168, Grenoble 38054, France [2] Univ. Grenoble Alpes, LPCV, Grenoble F-38054, France [3] CEA, DSV, iRTSV, LPCV, Grenoble F-38054, France [4] INRA, LPCV, Grenoble F-38054, France.
François
F
Parcy
Laboratoire de Reproduction et Développement des Plantes, CNRS, INRA, ENS Lyon, UCBL, Université de Lyon, Lyon 69364, France.
Teva
T
Vernoux
1] CNRS, Laboratoire de Physiologie Cellulaire and Végétale, UMR 5168, Grenoble 38054, France [2] Univ. Grenoble Alpes, LPCV, Grenoble F-38054, France [3] CEA, DSV, iRTSV, LPCV, Grenoble F-38054, France [4] INRA, LPCV, Grenoble F-38054, France.
Renaud
R
Dumas
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D009024:Morphogenesis; D010937:Plant Growth Regulators; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; C111371:MONOPTEROS protein, Arabidopsis; D010937:Plant Growth Regulators; D014157:Transcription Factors