title: The transcription corepressor LEUNIG interacts with the histone deacetylase HDA19 and mediator components MED14 (SWP) and CDK8 (HEN3) to repress transcription.
abstract: 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.
authors.affiliation: Institute of Life Science, School of Medicine, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, United Kingdom.
authors.forename: Deyarina
authors.initials: D
authors.lastname: Gonzalez
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Bowen
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Carroll
authors.forename: R Steven
authors.initials: RS
authors.lastname: Conlan
mesh_terms: 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
chemical_list: 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