The transcription corepressor LEUNIG interacts with the histone deacetylase HDA19 and mediator components MED14 (SWP) and CDK8 (HEN3) to repress transcription.
Transcription corepressors are general regulators controlling the expression of genes involved in multiple signaling pathways and developmental programs. Repression is mediated through mechanisms including the stabilization of a repressive chromatin structure over control regions and regulation of Mediator function inhibiting RNA polymerase II activity. Using whole-genome arrays we show that the Arabidopsis thaliana corepressor LEUNIG, a member of the GroTLE transcription corepressor family, regulates the expression of multiple targets in vivo. LEUNIG has a role in the regulation of genes involved in a number of different physiological processes including disease resistance, DNA damage response, and cell signaling. We demonstrate that repression of in vivo LEUNIG targets is achieved through histone deacetylase (HDAC)-dependent and -independent mechanisms. HDAC-dependent mechanisms involve direct interaction with HDA19, a class 1 HDAC, whereas an HDAC-independent repression activity involves interactions with the putative Arabidopsis Mediator components AtMED14/SWP and AtCDK8/HEN3. We suggest that changes in chromatin structure coupled with regulation of Mediator function are likely to be utilized by LEUNIG in the repression of gene transcription.
Gonzalez
Deyarina
D
Institute of Life Science, School of Medicine, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, United Kingdom.
Bowen
Adam J
AJ
Carroll
Thomas S
TS
Conlan
R Steven
RS
D029681:Arabidopsis Proteins / Q000378:metabolism*; D056850:Cyclin-Dependent Kinase 8; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D035264:Flowers / Q000378:metabolism; D006655:Histone Deacetylases / Q000378:metabolism*; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism*; D015203:Reproducibility of Results; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D056850:Cyclin-Dependent Kinase 8; D018844:Cyclin-Dependent Kinases; D006655:Histone Deacetylases; D012097:Repressor Proteins; D014157:Transcription Factors; C417768:LUG protein, Arabidopsis; C522174:AT5G63610 protein, Arabidopsis; C507152:HDA19 protein, Arabidopsis