title: Biochemical and redox characterization of the mediator complex and its associated transcription factor GeBPL, a GLABROUS1 enhancer binding protein.
abstract: The eukaryotic mediator integrates regulatory signals from promoter-bound transcription factors (TFs) and transmits them to RNA polymerase II (Pol II) machinery. Although redox signalling is important in adjusting plant metabolism and development, nothing is known about a possible redox regulation of mediator. In the present study, using pull-down and yeast two-hybrid assays, we demonstrate the association of mediator (MED) subunits MED10a, MED28 and MED32 with the GLABROUS1 (GL1) enhancer-binding protein-like (GeBPL), a plant-specific TF that binds a promoter containing cryptochrome 1 response element 2 (CryR2) element. All the corresponding recombinant proteins form various types of covalent oligomers linked by intermolecular disulfide bonds that are reduced in vitro by the thioredoxin (TRX) and/or glutathione/glutaredoxin (GRX) systems. The presence of recombinant MED10a, MED28 and MED32 subunits or changes of its redox state affect the DNA-binding capacity of GeBPL suggesting that redox-driven conformational changes might modulate its activity. Overall, these results advance our understanding of how redox signalling affects transcription and identify mediator as a novel actor in redox signalling pathways, relaying or integrating redox changes in combination with specific TFs as GeBPL.
authors: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences SLU, 901 83 Umeå, Sweden jehadgermany@gmail.com Gunnar.Wingsle@slu.se.
authors: Jehad
authors: J
authors: Shaikhali
authors: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences SLU, 901 83 Umeå, Sweden.
authors: Céline
authors: C
authors: Davoine
authors: Department of Medical Biochemistry and Biophysics, Umeå Plant Science Center, Umeå University, SE-901 87 Umeå, Sweden.
authors: Kristoffer
authors: K
authors: Brännström
authors: Université de Lorraine, Interactions Arbres-Microorganismes, UMR1136, F-54500 Vandoeuvre-lès-Nancy, France INRA, Interactions Arbres-Microorganismes, UMR1136, F-54280 Champenoux, France.
authors: Nicolas
authors: N
authors: Rouhier
authors: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences SLU, 901 83 Umeå, Sweden.
authors: Joakim
authors: J
authors: Bygdell
authors: Department of Medical Biochemistry and Biophysics, Umeå Plant Science Center, Umeå University, SE-901 87 Umeå, Sweden.
authors: Stefan
authors: S
authors: Björklund
authors: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences SLU, 901 83 Umeå, Sweden jehadgermany@gmail.com Gunnar.Wingsle@slu.se.
authors: Gunnar
authors: G
authors: Wingsle
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D054477:Glutaredoxins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D056892:Mediator Complex / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D020218:Response Elements; D013879:Thioredoxins / Q000378:metabolism; D014157:Transcription Factors; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D054477:Glutaredoxins; D056892:Mediator Complex; D021122:Protein Subunits; D011994:Recombinant Proteins; C000629467:STKR1 protein, Arabidopsis; D014157:Transcription Factors; C071556:GL1 protein, Arabidopsis; D013879:Thioredoxins; D005978:Glutathione
keywords: Arabidopsis thaliana; CryR2; GLABROUS1 enhancer-binding protein (GeBP); deoxyribonucleic acid (DNA)-binding; mediator; redox