Skip to main content
SLU:s publikationsdatabas (SLUpub)

Forskningsartikel2015Vetenskapligt granskad

Biochemical and redox characterization of the mediator complex and its associated transcription factor GeBPL, a GLABROUS1 enhancer binding protein

Shaikhali, Jehad; Davoine, Céline; Brännström, Kristoffer; Rouhier, Nicolas; Bygdell, Joakim; Björklund, Stefan; Wingsle, Gunnar

Sammanfattning

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.

Nyckelord

Arabidopsis thaliana; CryR2; deoxyribonucleic acid (DNA)-binding; GLABROUS1 enhancer-binding protein (GeBP); mediator; redox

Publicerad i

Biochemical Journal
2015, Volym: 468, sidor: 385-400
Utgivare: PORTLAND PRESS LTD