Life Sciences Commons^™

Histone Modifications Influence Mediator Interactions With Chromatin, Xuefeng Zhu, Yongqiang Zhang, Gudrun Bjornsdottir, Zhongle Liu, Amy Quan, Michael Costanzo, Marcela Davila Lopez, Jakub Orzechowski Westholm, Hans Ronne, Charles Boone, Claes M. Gustafsson, Lawrence C. Myers

Dartmouth Scholarship

The Mediator complex transmits activation signals from DNA bound transcription factors to the core transcription machinery. Genome wide localization studies have demonstrated that Mediator occupancy not only correlates with high levels of transcription, but that the complex also is present at transcriptionally silenced locations. We provide evidence that Mediator localization is guided by an interaction with histone tails, and that this interaction is regulated by their post-translational modifications. A quantitative, high-density genetic interaction map revealed links between Mediator components and factors affecting chromatin structure, especially histone deacetylases. Peptide binding assays demonstrated that pure wild-type Mediator forms stable complexes with the …