Biochemical and redox characterization of the mediator complex and its associated transcription factor GeBPL, a GLABROUS1 enhancer binding protein
2015 (English)In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 468, no 3, 385-400 p.Article in journal (Refereed) Published
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 combinationwith specific TFs as GeBPL.
Place, publisher, year, edition, pages
2015. Vol. 468, no 3, 385-400 p.
Arabidopsis thaliana, CryR2, deoxyribonucleic acid (DNA)-binding, GLABROUS1 enhancer-binding otein (GeBP), mediator, redox
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
IdentifiersURN: urn:nbn:se:umu:diva-109821DOI: 10.1042/BJ20150132ISI: 000360966500004PubMedID: 25877331OAI: oai:DiVA.org:umu-109821DiVA: diva2:859233