The 30th International Conference on Arabidopsis Research (ICAR 2019)

578 / 2019-04-10 06:48:26

THE ARABIDOPSIS MED12/13 FUNCTION AS ANTISILENCING FACTORS

DNA methylation, epigenetics

Plenary track > Epigenetics

We have conducted a genetic screen in Arabidopsis, looking for factors required for the transcription of DNA methylated genes. Mediator12 (MED12) and Mediator13 (MED13) were discovered through this process. Both proteins are the core components of the Pol II CDK8 kinase module. Genetic analysis show that MED12/13-dependent genes carry signatures of gene silencing. In the Arabidopsis atxr5/6 mutant, many genes and TEs are reactivated without losing repressive chromatin marks. Therefore, we hypothesized that the mutations of med12/13 can suppress the aberrant transcription of the atxr5/6 mutants. As expected, those atxr5/6 reactivated genes and TEs re-gained silencing in the absence of med12/13.