Project description:Faithful propagation of distinct chromatin states is crucial to maintain cellular identity. 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 the discovery of 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 histone H3K14, Mst2 specifically acetylates Brl1, a component of the histone H2B ubiquitin ligase complex (HULC). 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.
Project description:Faithful propagation of distinct chromatin states is crucial to maintain cellular identity. 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 the discovery of 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 histone H3K14, Mst2 specifically acetylates Brl1, a component of the histone H2B ubiquitin ligase complex (HULC). 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.
Project description: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.
Project description:Analysis of histone acetyl transferases (HATs) from the MYST and GNAT families in S. pombe to identify functional differences or overlap with regard to gene expression. Mutations were made to Elp3 and Gcn5 (GNAT family), and to Mst2 (MYST family). Mutants showed distinct phenotypes which were repressed or enhanced by mutant combinations. This SuperSeries is composed of the following subset Series: GSE17259: S. pombe acetyltransferase mutants identifies redundant pathways of gene regulation, dual-channel dataset GSE17262: S. pombe acetyltransferase mutants identifies redundant pathways of gene regulation, Affymetrix dataset Refer to individual Series
