The histone acetyltransferase Mst2 protects active chromatin from epigenetic silencing by acetylating the ubiquitin ligase Brl1

ABSTRACT: Faithful propagation of functionally distinct chromatin states is crucial for maintaining cellular identity, and its breakdown can lead to diseases such as cancer. Whereas mechanisms that sustain repressed states have been intensely studied, regulatory circuits that protect active chromatin from inactivating signals are not well understood. Here we discover a self-reinforcing feedback loop that preserves the transcription-competent state of RNA polymerase II transcribed genes. We found that the chromatin reader Pdp3 recruits the histone acetyltransferase Mst2 to H3K36me3 marked chromatin. Thereby, Mst2 binds to all transcriptionally active regions genome-wide. Besides acetylating histone H3K14, Mst2 also acetylates Brl1, a component of the histone H2B ubiquitin ligase complex. Brl1 acetylation results in increased histone H2B ubiquitination, which together with H3K14ac positively feeds back on transcription and prevents assembly of ectopic heterochromatin. Our work uncovers a molecular pathway that secures epigenome integrity and highlights the importance of opposing feedback loops for the partitioning of chromatin into transcriptionally active and inactive states.

OTHER RELATED OMICS DATASETS IN: PRJNA361034 PRJNA360957 GSE93434 PRJNA361033

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Schizosaccharomyces Pombe

SUBMITTER: Vytautas Iesmantavicius  

LAB HEAD: Marc Bühler

PROVIDER: PXD005714 | Pride | 2017-06-28

REPOSITORIES: Pride