The Histone Acetyltransferase Mst2 Protects Active Chromatin from Epigenetic Silencing by Acetylating the Ubiquitin Ligase Brl1

Valentin Flury, Paula Raluca Georgescu, Vytautas Iesmantavicius, Yukiko Shimada, Tahsin Kuzdere, Sigurd Braun*, Marc Bühler

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

33 Citations (Scopus)

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 report a positive feedback loop that preserves the transcription-competent state of RNA polymerase II-transcribed genes. We found that 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 increases histone H2B ubiquitination, which positively feeds back on transcription and prevents ectopic heterochromatin assembly. 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.

Original languageEnglish
JournalMolecular Cell
Volume67
Issue number2
Pages (from-to)294-307.e9
ISSN1097-2765
DOIs
Publication statusPublished - 2017
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2017 The Author(s)

Keywords

  • acetylomics
  • Brl1/BRE1
  • epigenetic gene silencing
  • Gcn5
  • H2B ubiquitin
  • H3K36me3
  • heterochromatin
  • histone modification
  • Mst2
  • RNA interference

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