IMITATION SWITCH is required for normal chromatin structure and gene repression in PRC2 target domains
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ABSTRACT:
PROVIDER: PRJNA633527 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR11806700_1.fastq.gz | Fastqsanger.gz | |||
| SRR11806700_2.fastq.gz | Fastqsanger.gz | |||
| SRR11806701_1.fastq.gz | Fastqsanger.gz | |||
| SRR11806701_2.fastq.gz | Fastqsanger.gz | |||
| SRR11806702_1.fastq.gz | Fastqsanger.gz |
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Project description:Polycomb Group (PcG) proteins are part of an epigenetic cell memory system that plays essential roles in multicellular development, stem cell biology, X-chromosome inactivation, and cancer. In animals, plants, and many fungi, Polycomb Repressive Complex 2 (PRC2) catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) to assemble transcriptionally repressed facultative heterochromatin. PRC2 is structurally and functionally conserved in the model fungus Neurospora crassa, and recent work in this organism has generated insights into PRC2 control and function. To identify new components of the facultative heterochromatin pathway, we performed a targeted screen of Neurospora deletion strains lacking individual ATP-dependent chromatin remodeling enzymes. We found the Neurospora homolog of IMITATION SWITCH (ISW) is critical for normal transcriptional repression, nucleosome organization, and establishment of typical histone methylation patterns in facultative heterochromatin domains. We also found that stable interaction between PRC2 and chromatin depends on ISW. A functional ISW ATPase domain is required for gene repression and H3K27 methylation. ISW homologs interact with accessory proteins to form multiple complexes with distinct functions. Using proteomics and molecular approaches, we identified three distinct Neurospora ISW-containing complexes. A triple mutant lacking three ISW-accessory factors and disrupting multiple ISW complexes led to widespread upregulation of PRC2 target genes and altered H3K27 methylation patterns, similar to an ISW-deficient strain. Taken together, our data show that ISW is a key component of the facultative heterochromatin pathway in Neurospora and that distinct ISW complexes perform an apparently overlapping role to regulate chromatin structure and gene repression at PRC2 target domains.
2021-01-05 | GSE150758 | GEO
Project description:Polycomb Group (PcG) proteins are part of an epigenetic cell memory system that plays essential roles in multicellular development, stem cell biology, X chromosome inactivation, and cancer. In animals, plants, and many fungi, Polycomb Repressive Complex 2 (PRC2) catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) to assemble transcriptionally repressed facultative heterochromatin. PRC2 is structurally and functionally conserved in the model fungus Neurospora crassa, and recent work in this organism has generated insights into PRC2 control and function. To identify components of the facultative heterochromatin pathway, we performed a targeted screen of Neurospora deletion strains lacking individual ATP-dependent chromatin remodeling enzymes. We found the Neurospora homolog of IMITATION SWITCH (ISW) is critical for normal transcriptional repression, nucleosome organization, and establishment of typical histone methylation patterns in facultative heterochromatin domains. We also found that stable interaction between PRC2 and chromatin depends on ISW. A functional ISW ATPase domain is required for gene repression and normal H3K27 methylation. ISW homologs interact with accessory proteins to form multiple complexes with distinct functions. Using proteomics and molecular approaches, we identified three distinct Neurospora ISW-containing complexes. A triple mutant lacking three ISW accessory factors and disrupting multiple ISW complexes led to widespread up-regulation of PRC2 target genes and altered H3K27 methylation patterns, similar to an ISW-deficient strain. Taken together, our data show that ISW is a key component of the facultative heterochromatin pathway in Neurospora, and that distinct ISW complexes perform an apparently overlapping role to regulate chromatin structure and gene repression at PRC2 target domains.
| S-EPMC7848606 | biostudies-literature
Project description:Polycomb Repressive Complex 2 (PRC2) plays crucial roles in transcriptional regulation and stem cell development. However, the context-specific functions associated with alternative subunits remain largely unexplored. Here we show that the related enzymatic subunits EZH1 and EZH2 undergo an expression switch during hematopoiesis. We examine the in vivo stoichiometry of the PRC2 complexes by quantitative proteomics and reveal the existence of an EZH1-SUZ12 sub-complex lacking EED. We provide evidence that EZH1 together with SUZ12 form a non-canonical PRC2 complex, occupy active chromatin domains in the absence of H3K27me3, and positively regulate gene expression. Loss of EZH2 expression leads to global repositioning of EZH1 chromatin occupancy to EZH2 targets. Moreover, we demonstrate that an erythroid-specific enhancer mediates transcriptional activation of EZH1, and a switch from GATA2 to GATA1 controls the developmental EZH1/2 switch by differential association with EZH1 enhancers during erythropoiesis. Thus, the lineage- and developmental stage-specific regulation of PRC2 expression and subunit composition leads to a switch from canonical silencing to non-canonical PRC2 functions during blood stem cell specification. Analysis of genomic occupancy of EZH1, EZH2, EED, SUZ12, various histone marks and transcription factors in primary human fetal liver proerythroblasts by ChIP-seq. Sample GSM970262 was used as the input DNA sample.
2015-01-01 | E-GEOD-59087 | biostudies-arrayexpress
Project description:Polycomb Repressive Complex 2 (PRC2) plays an essential role in development by catalysing trimethylation of histone H3 lysine 27 (H3K27me3), resulting in gene repression. PRC2 consists of two sub-complexes, PRC2.1 and PRC2.2, in which the PRC2 core associates with distinct ancillary subunits such as MTF2 and JARID2, respectively. Both MTF2, present in PRC2.1, and JARID2, present in PRC2.2, play a role in core PRC2 recruitment to target genes in mouse embryonic stem cells (mESCs). However, it remains unclear how these distinct sub-complexes cooperate to establish H3K27me3 domains. Here, we combine a range of Polycomb mutant mESCs with chemical inhibition of PRC2 catalytic activity, to systematically dissect their relative contributions to PRC2 binding to target loci. We find that PRC2.1 and PRC2.2 mediate two distinct paths for recruitment, with mutually reinforced binding. Part of the cross-talk between PRC2.1 and PRC2.2 occurs via their catalytic product H3K27me3, which is bound by the PRC2 core-subunit EED, thereby mediating a positive feedback. Strikingly, removal of either JARID2 or H3K27me3 only has a minor effect on PRC2 recruitment, whereas their combined ablation largely attenuates PRC2 recruitment. This strongly suggests an unexpected redundancy between JARID2 and EED-H3K27me3-mediated recruitment of PRC2. Furthermore, we demonstrate that all core PRC2 recruitment occurs through the combined action of MTF2-mediated recruitment of PRC2.1 to DNA and PRC1-mediated recruitment of JARID2-containing PRC2.2. Both axes of binding are supported by EED-H3K27me3 positive feedback, but to a different degree. Finally, we provide evidence that PRC1 and PRC2 mutually reinforce reciprocal binding. Together, these data disentangle the interdependent and cooperative interactions between Polycomb complexes that are important to establish Polycomb repression at target sites.
2021-09-22 | PXD020684 | Pride
Project description:Polycomb Repressive Complex 2 (PRC2) plays an essential role in development by catalysing trimethylation of histone H3 lysine 27 (H3K27me3), resulting in gene repression. PRC2 consists of two sub-complexes, PRC2.1 and PRC2.2, in which the PRC2 core associates with distinct ancillary subunits such as MTF2 and JARID2, respectively. Both MTF2, present in PRC2.1, and JARID2, present in PRC2.2, play a role in core PRC2 recruitment to target genes in mouse embryonic stem cells (mESCs). However, it remains unclear how these distinct sub-complexes cooperate to establish H3K27me3 domains. Here, we combine a range of Polycomb mutant mESCs with chemical inhibition of PRC2 catalytic activity, to systematically dissect their relative contributions to PRC2 binding to target loci. We find that PRC2.1 and PRC2.2 mediate two distinct paths for recruitment, with mutually reinforced binding. Part of the cross-talk between PRC2.1 and PRC2.2 occurs via their catalytic product H3K27me3, which is bound by the PRC2 core-subunit EED, thereby mediating a positive feedback. Strikingly, removal of either JARID2 or H3K27me3 only has a minor effect on PRC2 recruitment, whereas their combined ablation largely attenuates PRC2 recruitment. This strongly suggests an unexpected redundancy between JARID2 and EED-H3K27me3-mediated recruitment of PRC2. Furthermore, we demonstrate that all core PRC2 recruitment occurs through the combined action of MTF2-mediated recruitment of PRC2.1 to DNA and PRC1-mediated recruitment of JARID2-containing PRC2.2. Both axes of binding are supported by EED-H3K27me3 positive feedback, but to a different degree. Finally, we provide evidence that PRC1 and PRC2 mutually reinforce reciprocal binding. Together, these data disentangle the interdependent and cooperative interactions between Polycomb complexes that are important to establish Polycomb repression at target sites.
2020-08-07 | PXD014290 | Pride
Project description:Polycomb Repressive Complex 2 (PRC2) plays crucial roles in transcriptional regulation and stem cell development. However, the context-specific functions associated with alternative subunits remain largely unexplored. Here we show that the related enzymatic subunits EZH1 and EZH2 undergo an expression switch during hematopoiesis. We examine the in vivo stoichiometry of the PRC2 complexes by quantitative proteomics and reveal the existence of an EZH1-SUZ12 sub-complex lacking EED. We provide evidence that EZH1 together with SUZ12 form a non-canonical PRC2 complex, occupy active chromatin domains in the absence of H3K27me3, and positively regulate gene expression. Loss of EZH2 expression leads to global repositioning of EZH1 chromatin occupancy to EZH2 targets. Moreover, we demonstrate that an erythroid-specific enhancer mediates transcriptional activation of EZH1, and a switch from GATA2 to GATA1 controls the developmental EZH1/2 switch by differential association with EZH1 enhancers during erythropoiesis. Thus, the lineage- and developmental stage-specific regulation of PRC2 expression and subunit composition leads to a switch from canonical silencing to non-canonical PRC2 functions during blood stem cell specification. Transcriptional profiling in primary human fetal liver proerythroblasts upon lentiviral shRNA-mediated knockdown of EZH1, EZH2, EED, or SUZ12 by RNA-seq analysis.
2015-01-01 | E-GEOD-59089 | biostudies-arrayexpress
Project description:The transcriptional activating and repressive functions performed by Trithorax and Polycomb group complexes, respectively, are critical for to maintain cellular fates in ontogeny and in cancer. Here we report that leukemias initiated by a Trithorax-related oncogene, MLL-AF9, depend upon the Polycomb Repressive Complex 2 (PRC2) to sustain a transformed cellular state. RNAi mediated suppression of PRC2 subunits is sufficient to inhibit proliferation of MLL-AF9 leukemias, with little impact on growth of non-transformed cells. This requirement is partly due to PRC2-mediated transcriptional repression of several anti-self-renewal regulators, including Cdkn2a. These results suggest that, unlike the classical antagonism generally observed between Polycomb and Trithorax group proteins during development, the activities of these two pathways can cooperate to promote myeloid neoplasia. In order to understand downstream targets of PRC2 complex in MLL-AF9 leukemia, we performed array in murine MLL-AF9/NrasG12D cell line under the condition that two subunits of PRC2(Eed and Suz12) were suppressed by using shRNAs.
2013-07-01 | E-GEOD-34183 | biostudies-arrayexpress
Project description:Small cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis. Expression array analysis of 23 SCLC cases and 42 normal tissues revealed that EZH2 and other PRC2 members were highly expressed in SCLC. ChIP-seq for H3K27me3 suggested that genes with H3K27me3(+) in SCLC were extended not only to PRC2-target genes in ES cells but also to other target genes such as cellular adhesion-related genes. These H3K27me3(+) genes in SCLC were repressed significantly, and introduction of the most repressed gene JUB into SCLC cell line lead to growth inhibition. Shorter overall survival of clinical SCLC cases correlated to repression of JUB alone, or a set of four genes including H3K27me3(+) genes. Treatment with EZH2 inhibitors, DZNep and GSK126, resulted in growth repression of SCLC cell lines. High PRC2 expression was suggested to contribute to gene repression in SCLC, and may play a role in genesis of SCLC.
2017-05-26 | GSE99312 | GEO
Project description:The histone mark H3K27me3 and its reader/writer Polycomb repressive complex 2 (PRC2) mediate widespread transcriptional repression in stem and progenitor cells. Mechanisms that regulate this activity are critical for tissue development but poorly understood. Here we show that the E3 ubiquitin ligase FBXO11 relieves PRC2-mediated repression during erythroid maturation by targeting its newly identified substrate BAHD1, an H3K27me3 reader that recruits transcriptional co-repressors. Erythroblasts lacking FBXO11 are developmentally delayed, with reduced expression of maturation-associated genes, most of which harbor bivalent histone marks (activating H3K4me3 and repressive H3K27me3), bind BAHD1, and fail to recruit the erythroid transcription factor GATA1. The BAHD1 complex interacts physically with PRC2 and depletion of either component restores FBXO11-deficient erythroid gene expression. Previous studies showed that FBXO11 promotes B-cell development and inhibits lymphomagenesis by degrading the transcriptional repressor BCL6. We show that in aggressive B-cell lymphoma lines, depletion of FBXO11 causes the accumulation of both BCL6 and BAHD1, and that suppression of BAHD1 slows cell expansion. Our studies identify BAHD1 as a novel effector of PRC2-mediated repression and reveal how a single E3 ubiquitin ligase eliminates PRC2 repression at developmentally poised bivalent genes during erythropoiesis. The FBXO11-BAHD1 regulatory axis may function in other developmental pathways, including B-lymphopoiesis and lymphomagenesis.
2020-12-31 | GSE115357 | GEO
Project description:Polycomb repressive complex-2 (PRC2) is a group of proteins that play important role during development and in cell differentiation. PRC2 is a histone-modifying complex that catalyses methylation of lysine 27 of histone H3 (H3K27me3) at differentiation genes leading to their transcriptional repression. JARID2 is a co-factor of PRC2 and is important for targeting PRC2 to chromatin as well as modulating its activity. Here, we show that in many human cells, including human epidermal keratinocytes, JARID2 predominantly exists as a novel low molecular weight form, which lacks the N-terminal PRC2-interacting domain (ΔN-JARID2). We show that ΔN-JARID2 is a cleaved product of full-length JARID2 spanning the C-terminal conserved region consisting of jumonji domains. JARID2 knockout in keratinocytes results in up-regulation of cell cycle genes and repression of many epidermal differentiation genes. Surprisingly, repression of epidermal differentiation genes in JARID2-null keratinocytes can be relieved by expression of ΔN-JARID2 suggesting that this form promotes activation of these genes and has opposing function to that of PRC2 in regulation of differentiation. We propose that a switch from expression of full-length JARID2 to ΔN-JARID2 is important for the up-regulation of genes during differentiation.
2019-02-19 | GSE102116 | GEO