Similar Datasets
Project description:Taf4 (TATA-box binding protein-associated factor 4) is a subunit of the general transcription factor TFIID, a component of the RNA polymerase II pre-initiation complex that interacts with tissue-specific transcription factors to regulate gene expression. Properly regulated gene expression is particularly important in the intestinal epithelium that is constantly renewed from stem cells. We investigated the role of Taf4 in the murine intestinal epithelium using tissue-specific inactivation. Taf4 inactivation during embryogenesis compromised gut morphogenesis and the emergence of adult-type stem cells, ultimately leading to death. In adults, Taf4 loss perturbed the stem cell compartment and the associated Paneth cells in the stem cell niche, epithelial turnover and differentiation of mature cells, thus exacerbating the response to inflammatory challenge and potentiating Apc-driven tumorigenesis. In addition, Taf4 inactivation ex vivo in organoids prevented budding formation and maintenance. Combining immunohistology with bulk RNA-seq, ATAC-seq and single-cell RNA-seq, showed that Taf4 loss caused broad chromatin remodeling, and a strong reduction in the numbers of stem and progenitor cells with a concomitant increase in an undifferentiated cell population that displayed high activity of the Ezh2 and Suz12 components of Polycomb Repressive Complex 2 (PRC2). In line with this observation, treatment of Taf4-mutant organoids with a specific Ezh2 inhibitor restored buddings, cell proliferation and the stem/progenitor compartment. Our results reveal the critical role of Taf4 in intestinal development and homeostasis and a novel mechanism by which Taf4 acts to maintain the stem/progenitor compartment by counteracting PRC2 repression of the stem cell gene expression program.
2023-01-05 | GSE205441 | GEO
Project description:Taf4 (TATA-box binding protein-associated factor 4) is a subunit of the general transcription factor TFIID, a component of the RNA polymerase II pre-initiation complex that interacts with tissue-specific transcription factors to regulate gene expression. Properly regulated gene expression is particularly important in the intestinal epithelium that is constantly renewed from stem cells. We investigated the role of Taf4 in the murine intestinal epithelium using tissue-specific inactivation. Taf4 inactivation during embryogenesis compromised gut morphogenesis and the emergence of adult-type stem cells, ultimately leading to death. In adults, Taf4 loss perturbed the stem cell compartment and the associated Paneth cells in the stem cell niche, epithelial turnover and differentiation of mature cells, thus exacerbating the response to inflammatory challenge and potentiating Apc-driven tumorigenesis. In addition, Taf4 inactivation ex vivo in organoids prevented budding formation and maintenance. Combining immunohistology with bulk RNA-seq, ATAC-seq and single-cell RNA-seq, showed that Taf4 loss caused broad chromatin remodeling, and a strong reduction in the numbers of stem and progenitor cells with a concomitant increase in an undifferentiated cell population that displayed high activity of the Ezh2 and Suz12 components of Polycomb Repressive Complex 2 (PRC2). In line with this observation, treatment of Taf4-mutant organoids with a specific Ezh2 inhibitor restored buddings, cell proliferation and the stem/progenitor compartment. Our results reveal the critical role of Taf4 in intestinal development and homeostasis and a novel mechanism by which Taf4 acts to maintain the stem/progenitor compartment by counteracting PRC2 repression of the stem cell gene expression program.
2023-01-05 | GSE205329 | GEO
Project description:Taf4 (TATA-box binding protein-associated factor 4) is a subunit of the general transcription factor TFIID, a component of the RNA polymerase II pre-initiation complex that interacts with tissue-specific transcription factors to regulate gene expression. Properly regulated gene expression is particularly important in the intestinal epithelium that is constantly renewed from stem cells. We investigated the role of Taf4 in the murine intestinal epithelium using tissue-specific inactivation. Taf4 inactivation during embryogenesis compromised gut morphogenesis and the emergence of adult-type stem cells, ultimately leading to death. In adults, Taf4 loss perturbed the stem cell compartment and the associated Paneth cells in the stem cell niche, epithelial turnover and differentiation of mature cells, thus exacerbating the response to inflammatory challenge and potentiating Apc-driven tumorigenesis. In addition, Taf4 inactivation ex vivo in organoids prevented budding formation and maintenance. Combining immunohistology with bulk RNA-seq, ATAC-seq and single-cell RNA-seq, showed that Taf4 loss caused broad chromatin remodeling, and a strong reduction in the numbers of stem and progenitor cells with a concomitant increase in an undifferentiated cell population that displayed high activity of the Ezh2 and Suz12 components of Polycomb Repressive Complex 2 (PRC2). In line with this observation, treatment of Taf4-mutant organoids with a specific Ezh2 inhibitor restored buddings, cell proliferation and the stem/progenitor compartment. Our results reveal the critical role of Taf4 in intestinal development and homeostasis and a novel mechanism by which Taf4 acts to maintain the stem/progenitor compartment by counteracting PRC2 repression of the stem cell gene expression program.
2023-01-05 | GSE205326 | GEO
Project description:General transcription factor TAF4 antagonizes epigenetic silencing by Polycomb to maintain intestine stem cell functions
| PRJNA845368 | ENA
Project description:General transcription factor TAF4 antagonizes epigenetic silencing by Polycomb to maintain intestine stem cell functions [RNA-seq]
| PRJNA844396 | ENA
Project description:General transcription factor TAF4 antagonizes epigenetic silencing by Polycomb to maintain intestine stem cell functions [ATAC-seq]
| PRJNA844389 | ENA
Project description:General transcription factor TAF4 antagonizes epigenetic silencing by Polycomb to maintain intestine stem cell functions [scRNA-seq]
| PRJNA845448 | ENA
Project description:Wapl protein regulates binding of the cohesin complex to chromosomes during interphase and helps remove cohesin from chromosomes at mitosis. We isolated a dominant mutation in wapl (wapl(AG)) in a screen for mutations that counteract silencing mediated by an engrailed Polycomb-group response element. wapl(AG) hemizygotes die as pharate adults and have an extra sex combs phenotype characteristic of males with mutations in Polycomb-group (PcG) genes. The wapl gene encodes two proteins, a long form and a short form. wapl(AG) introduces a stop codon at amino acid 271 of the long form and produces a truncated protein. The expression of a transgene encoding the truncated Wapl-AG protein causes an extra-sex-comb phenotype similar to that seen in the wapl(AG) mutant. Mutations in the cohesin-associated genes Nipped-B and pds5 suppress and enhance wapl(AG) phenotypes, respectively. A Pds5-Wapl complex (releasin) removes cohesin from DNA, while Nipped-B loads cohesin. This suggests that Wapl-AG might exert its effects through changes in cohesin binding. Consistent with this model, Wapl-AG was found to increase the stability of cohesin binding to polytene chromosomes. Our data suggest that increasing cohesin stability interferes with PcG silencing at genes that are co-regulated by cohesin and PcG proteins.
| S-EPMC3478686 | biostudies-literature
Project description:Trimethylation of histone H3 lysine 27 (H3K27me3) by Polycomb repressive complex 2 (PRC2) is essential for transcriptional silencing of Polycomb target genes, whereas acetylation of H3K27 (H3K27ac) has recently been shown to be associated with many active mammalian genes. The Trithorax protein (TRX), which associates with the histone acetyltransferase CBP, is required for maintenance of transcriptionally active states and antagonizes Polycomb silencing, although the mechanism underlying this antagonism is unknown. Here we show that H3K27 is specifically acetylated by Drosophila CBP and its deacetylation involves RPD3. H3K27ac is present at high levels in early embryos and declines after 4 hours as H3K27me3 increases. Knockdown of E(Z) decreases H3K27me3 and increases H3K27ac in bulk histones and at the promoter of the repressed Polycomb target gene abd-A, suggesting that these indeed constitute alternative modifications at some H3K27 sites. Moderate overexpression of CBP in vivo causes a global increase in H3K27ac and a decrease in H3K27me3, and strongly enhances Polycomb mutant phenotypes. We also show that TRX is required for H3K27 acetylation. TRX overexpression also causes an increase in H3K27ac and a concomitant decrease in H3K27me3 and leads to defects in Polycomb silencing. Chromatin immunoprecipitation coupled with DNA microarray (ChIP-chip) analysis reveals that H3K27ac and H3K27me3 are mutually exclusive and that H3K27ac and H3K4me3 signals coincide at most sites. We propose that TRX-dependent acetylation of H3K27 by CBP prevents H3K27me3 at Polycomb target genes and constitutes a key part of the molecular mechanism by which TRX antagonizes or prevents Polycomb silencing.
| S-EPMC2730368 | biostudies-literature
Project description:Histone H3 phosphorylation is a critical step that couples signal transduction pathways to gene regulation. To specifically assess the transcriptional regulatory functions of H3 phosphorylation, we developed an in vivo targeting approach and found that the H3 kinase MSK1 is a direct and potent transcriptional activator. Targeting of this H3 kinase to the endogenous c-fos promoter is sufficient to activate its expression without the need of upstream signaling. Moreover, targeting MSK1 to the α-globin promoter induces H3 S28 phosphorylation and reactivates expression of this polycomb-silenced gene. Importantly, we discovered a mechanism whereby H3 S28 phosphorylation not only displaces binding of the polycomb-repressive complexes, but it also induces a methyl-acetylation switch of the adjacent K27 residue. Our findings show that signal transduction activation can directly regulate polycomb silencing through a specific histone code-mediated mechanism.
| S-EPMC3041124 | biostudies-other