Project description:High-throughput sequencing of numerous patient samples has identified a myriad of frequent mutations of epigenetic regulators in human cancers, including recently discovered mutations in histone-encoding genes. Lysine-to-methionine mutations such as H3K27M and H3K36M share a common mechanism of inhibiting methylation pathways at the genome-wide level to promote tumorigenesis. However, the mechanism underlying the molecular and cellular changes due to H3G34 alterations is yet to be determined. H3G34 itself is not post-translationally modified; however, G34 lies in close proximity to K36, which undergoes methylation during transcriptional elongation. In Hela cells, H3.3G34L/W mutations have no effect on global levels of methylation on H3K36, H3K27, or other major methylation sites on endogenous histone H3, which include both H3.3 and the canonical H3.1/H3.2 proteins. However, long exposures of the blots revealed that methylation on the ectopic Flag-H3.3 proteins are affected by G34 mutations: with di- and trimethylation on H3K36 and H3K27ac reduced whereas H3K27me3 increased in the G34L and G34W mutated H3.3 compared to the WT H3.3. ChIP-seq results showed that mutations of H3.3G34 affect methylation on H3K36 and H3K27 in cis. G34L/W mutants abolish SETD2 methylation of H3K36. In contrast, the enzymatic activities of both EZH2 and p300 on H3K27 are not affected by G34 mutations. Consistent with changes in H3K27me3 and H3K36m3 levels, we found increased binding of PRC2 (EZH2, SUZ12 and EED) and PRC1 complex components (CBX8 and RING2) and reduced binding of H3.3K36me3 reader such as ZMYND11 to the G34 mutants. In summary, our study revealed that histone H3.3 G34 mutations alter histone K36 and K27 methylation in cis, and affect the binding of readers specific to K36 or K27 methylation.
Project description:Recognition of modified histones by “reader” proteins plays a critical role in the regulation of transcription1. H3K36 trimethylation (H3K36me3) is deposited onto the nucleosomes in the transcribed regions following RNA polymerase II (Pol II) elongation. In yeast, this mark in turn recruits epigenetic regulators to reset the chromatin at an appropriate state to suppress cryptic transcription2,3. However, much less is known about the role of H3K36me3 in transcription regulation in mammals. This is further complicated by the transcription-coupled incorporation of the histone variant H3.3 in gene bodies4. Here we show that the candidate tumor suppressor ZMYND11 specifically recognizes H3K36me3 on H3.3 (H3.3K36me3) and regulates Pol II elongation. Structural studies reveal that in addition to the trimethyl-lysine binding by an aromatic cage within the PWWP domain, the H3.3-dependent recognition is mediated by the encapsulation of the H3.3-specific “Ser31” residue in a composite pocket formed by the tandem bromo-PWWP domains of ZMYND11. ChIP-sequencing analysis reveal a genome-wide colocalization of ZMYND11 with H3K36me3 and H3.3 in gene bodies, and its occupancy requires the pre-deposition of H3.3K36me3. Although ZMYND11 is associated with highly expressed genes, it functions as an unconventional transcription corepressor via modulating the transition of the promoter-proximal paused Pol II to elongation. ZMYND11 is critical for the repression of a transcriptional program that is essential for tumor cell growth; higher expression of ZMYND11 is observed in triple-negative breast cancer patients with better prognosis. Consistently, overexpression of ZMYND11 suppresses cancer cell growth and tumor formation in mice. Together, this study identifies ZMYND11 as an H3.3-specific reader of H3K36me3 that links the histone variant-mediated transcription elongation control to tumor suppression. ChIP-seq analysis of ZMYND11, H3K36me3 in U2OS cells and ZMYND11 knockdown cells; ChIP-seq of H3.3 in Flag-H3.3 stable U2OS cells; RNA-seq of ZNYMD11 depleted U2OS cells.
Project description:This SuperSeries is composed of the following subset Series: GSE16882: Histone H1 binding is restricted by histone variant H3.3 (Nucleosome) GSE16883: Histone H1 binding is restricted by histone variant H3.3 (DamID) GSE16884: Histone H1 binding is restricted by histone variant H3.3 (Expression) GSE19764: Histone H1 binding is restricted by histone variant H3.3 (FAIRE) Refer to individual Series
Project description:Recognition of modified histones by “reader” proteins plays a critical role in the regulation of transcription1. H3K36 trimethylation (H3K36me3) is deposited onto the nucleosomes in the transcribed regions following RNA polymerase II (Pol II) elongation. In yeast, this mark in turn recruits epigenetic regulators to reset the chromatin at an appropriate state to suppress cryptic transcription2,3. However, much less is known about the role of H3K36me3 in transcription regulation in mammals. This is further complicated by the transcription-coupled incorporation of the histone variant H3.3 in gene bodies4. Here we show that the candidate tumor suppressor ZMYND11 specifically recognizes H3K36me3 on H3.3 (H3.3K36me3) and regulates Pol II elongation. Structural studies reveal that in addition to the trimethyl-lysine binding by an aromatic cage within the PWWP domain, the H3.3-dependent recognition is mediated by the encapsulation of the H3.3-specific “Ser31” residue in a composite pocket formed by the tandem bromo-PWWP domains of ZMYND11. ChIP-sequencing analysis reveal a genome-wide colocalization of ZMYND11 with H3K36me3 and H3.3 in gene bodies, and its occupancy requires the pre-deposition of H3.3K36me3. Although ZMYND11 is associated with highly expressed genes, it functions as an unconventional transcription corepressor via modulating the transition of the promoter-proximal paused Pol II to elongation. ZMYND11 is critical for the repression of a transcriptional program that is essential for tumor cell growth; higher expression of ZMYND11 is observed in triple-negative breast cancer patients with better prognosis. Consistently, overexpression of ZMYND11 suppresses cancer cell growth and tumor formation in mice. Together, this study identifies ZMYND11 as an H3.3-specific reader of H3K36me3 that links the histone variant-mediated transcription elongation control to tumor suppression.
Project description:Germ cells have evolved unique mechanisms to ensure an everlasting transmission of their genetic and epigenetic information to future generations, whose alteration compromises germ cell immortality. In many instances, epigenetic factors play fundamental roles in these mechanisms. Despite H3K36 and H3K27 methyltransferases shape and propagate over generations a pattern of histone methylation essential for C. elegans germ cell maintenance, the role of respective histone demethylases in this context remains mainly unexplored. Here, we show that jmjd-5 regulates the level of H3K36me2 and H3K27me3, preserves germ cell immortality at high temperature and protects germ cell identity by controlling somatic and germline gene expression. Strikingly, the biological and transcriptional effects of jmjd-5 loss can be hindered by the removal of demethylases for H3K27, indicating that H3K36/K27 demethylases act in a transcriptional framework and promote the accurate balance between H3K36 and H3K27 methylation required for the maintenance of germ cell immortality. Furthermore, we found that in wild-type, but not in jmjd-5 mutant animals, alterations of H3K27 and H3K36 methylation and transcription occur at high temperature, suggesting a role for jmjd-5 in adaptation to environmental changes.
Project description:The goal of this study is to understand the genome-wide alterations in chromatin landscapy induced by a histone mutation (H3.3 K36M) derived from chondroblastomas Examination of H3K36M mutations to H3WT Chondroblastomas.
Project description:The goal of this study is to understand the genome-wide alterations in chromatin landscapy induced by a histone mutation (H3.3 K36M) derived from chondroblastomas Examination of the transcriptome changes of Ring1a and Ring1b knockdown in mouse mesenchymal progenitor cells
Project description:Histone chaperones and chromatin remodelers control nucleosome dynamics, essential for transcription, replication, and DNA repair. The histone chaperone Anti-Silencing Factor 1 (ASF1) plays a central role in facilitating CAF-1-mediated replication-dependent H3.1 deposition and HIRA-mediated replication-independent H3.3 deposition in yeast and metazoans. Whether ASF1 function is evolutionarily conserved in plants is unknown. Here, we show that Arabidopsis ASF1 proteins display an exclusive preference for the H3.3-depositing HIRA complex. Simultaneous mutation of both Arabidopsis ASF1 genes caused a decrease in chromatin density and ectopic H3.1 occupancy at loci typically enriched with H3.3. Genetic, transcriptomic, and proteomic data indicate that ASF1 proteins strongly prefer the HIRA complex over CAF-1. asf1 mutants also displayed an increase in spurious Pol II transcriptional initiation, and showed defects in the maintenance of gene body CG DNA methylation and in the distribution of histone modifications. Furthermore, ectopic targeting of ASF1 caused excessive histone deposition, less accessible chromatin, and gene silencing. These findings reveal the importance of ASF1-mediated H3.3-H4 deposition via the HIRA pathway for proper epigenetic regulation of the genome.
Project description:Study to investigate the role of histone residues H3K4 and H3K36 for gene expression, histone localization and neuronal lineage specification by mutation of K4 and K36 in H3.3 to alanine. Histone variant H3.3 differs from the canonical H3.1/H3.2 by only 4 to 5 amino acids, which are necessary for nucleosome assembly independent of DNA replication, and is encoded by two gene copies. Complete loss of the two H3.3 genes (H3f3a and H3f3b) leads to embryonic lethality while single gene knockout yields viable mice. We used CRISPR-Cas9 to delete H3f3a and introduce homozygous point-mutations into H3f3b, thus ensuring that the entire pool of H3.3 protein carries the mutation of interest. We differentiated H3.3ctrl (H3f3a knock-out; H3f3b wild type), H3.3K4A mutant (H3f3a knock-out; H3f3b K4A) and H3.3K36A mutant (H3f3a knock-out; H3f3b K36A) ESCs into glutamatergic neurons. To assess the effect of the K4A mutation on Pol II activity, nascent RNA levels were mesaured by PRO-seq.