Similar Datasets
Project description:A Conserved Switch to Less Catalytically Active Polycomb Repressive Complexes in non-dividing cells
| PRJNA824861 | ENA
Project description:DNA methylation regulates gene expression in a variety of processes, including mouse embryonic development. Four catalytically active enzymes function in mice as DNA methyltransferases (Dnmts) and as transcriptional regulators. Inactivation of Dnmt3b results in mouse embryonic lethality, but which activities are involved is unclear. Here we show that catalytically inactive Dnmt3b restores a majority of methylation and expression changes deregulated in the absence of Dnmt3b, and as a result, mice survive embryonic development. Thus, Dnmt3b functions as an accessory cofactor supporting catalytic activities performed by other Dnmts. We further demonstrate that Dnmt3b is linked to a control of major developmental pathways, including Wnt and hedgehog signaling. Dnmt3b directly represses Wnt9b whose aberrant up-regulation contributes to embryonic lethality of Dnmt3b knockout embryos. Our results highlight that Dnmt3b is a multifaceted protein that serves as an enzyme, an accessory factor for other methyltransferases, and as a transcriptional repressor in mouse embryogenesis.
| S-EPMC6763448 | biostudies-literature
Project description:The polycomb group (PcG) proteins are a large and diverse family that epigenetically repress the transcription of key developmental genes. They form three broad groups of polycomb repressive complexes (PRCs) known as PRC1, PRC2 and Polycomb Repressive DeUBiquitinase, each of which modifies and/or remodels chromatin by distinct mechanisms that are tuned by having variable compositions of core and accessory subunits. Until recently, relatively little was known about how the various PcG proteins assemble to form the PRCs; however, studies by several groups have now allowed us to start piecing together the PcG puzzle. Here, we discuss some highlights of recent PcG structures and the insights they have given us into how these complexes regulate transcription through chromatin.
| S-EPMC5310723 | biostudies-literature
Project description:Mammalian SWI/SNF (mSWI/SNF or BAF) chromatin remodeling complexes play critical roles in regulating DNA accessibility and gene expression and are comprised of three final-form assemblies, cBAF, PBAF, and ncBAF, which exhibit distinct modular organization, chromatin targeting, and roles in disease. However, the contributions of each subcomplex and their constituent subunits to gene expression remain incompletely defined. Here, we performed a large-scale CRISPR-Cas9 knockout screen targeting mSWI/SNF subunits individually and in selected combinations, followed by single-cell RNA-sequencing (Perturb-seq) and SHARE-Seq. We uncover complex- and module-specific contributions across cell regulatory pathways, define paralog subunit relationships, and identify shifted functions upon perturbations. Finally, we superimpose single-cell perturbation signatures over bulk primary human tumor gene expression profiles, defining unique subunit-specific signatures and identifying tumor features that mirror BAF loss-of-function. Taken together, these data highlight the utility of large-scale single-cell genomics to uncover gene expression and chromatin accessibility signatures in human disease states.
2023-04-05 | GSE200201 | GEO
Project description:Reforestation is effective in restoring ecosystem functions and enhancing ecosystem services of degraded land. The three most commonly employed reforestation methods of natural reforestation, artificial reforestation with native Masson pine (Pinus massoniana Lamb.), and introduced slash pine (Pinus elliottii Engelm.) plantations were equally successful in biomass yield in southern China. However, it is not known if soil ecosystem functions, such as nitrogen (N) cycling, are also successfully restored. Here, we employed a functional microarray to illustrate soil N cycling. The composition and interactions of N-cycling genes in soils varied significantly with reforestation method. Natural reforestation had more superior organization of N-cycling genes, and higher functional potential (abundance of ammonification, denitrification, assimilatory, and dissimilatory nitrate reduction to ammonium genes) in soils, providing molecular insight into the effects of reforestation.
2019-11-04 | GSE100379 | GEO
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare palatal epithelial basal cell transcriptomes between infrequently and frequently dividing cells (IDC/FDCs). Methods: RNA was isolated from 200-1000 palatal basal epithelial cells and libraries prepared using the SoLo RNA-Seq library preparation kit (NuGEN). mRNA profiles of 14-day doxycycline chased K5-tTA;tetO-H2B-GFP (containing populations of slow-cycling GFP-HI and fast-cycling GFP-LO) mice were generated with 6 matched samples using an Illumina HiSeq4000. RNA Sequencing Allows for Differential Gene Expression Analysis of infrequently dividing and frequently dividing cells (IDC/FDC). RNA-seq fastq files were trimmed and aligned to the latest mouse genome, mm10 (GRCm38/GCA_000001635.2) using BBMap. A matrix of the data was generated using featureCounts. RNAseq data was analyzed with DESeq2. All statistical analyses were performed using R version 3.4.1 and RStudio version 1.0.143. Validation was performed using lineage tracing and immunofluorescence immunohistochemistry. Results: Using an optimized data analysis workflow, approximately 2% of the transcripts showed differential expression between the GFP-HI and GFO-LO palatal basal epithelial cell with a p value <0.05. Analysis of differentially expressed genes uncovered several as yet uncharacterized genes that may contribute to oral epithelial stem cell, such as Lrig1 and Igfbp5 as followed up on in the associated manuscript. Conclusions: Our study represents the first detailed analysis of palatal basal epithelial stem cell transcriptomes, with biologic replicates, generated by RNA-seq technology. Our results show GFP-LO infrequently dividing cells are express a distinct transcriptional profile compared to frequently dividing neighbor cells such as Lrig1 and Igfbp5.
2019-10-22 | GSE139146 | GEO
Project description:Switching from repressed to active status in chromatin regulation is part of the critical responses that plants deploy to survive in an ever-changing environment. We previously reported that HOS15, a WD40-repeat protein, is involved in histone deacetylation and cold tolerance in Arabidopsis However, it remained unknown how HOS15 regulates cold responsive genes to affect cold tolerance. Here, we show that HOS15 interacts with histone deacetylase 2C (HD2C) and both proteins together associate with the promoters of cold-responsive COR genes, COR15A and COR47 Cold induced HD2C degradation is mediated by the CULLIN4 (CUL4)-based E3 ubiquitin ligase complex in which HOS15 acts as a substrate receptor. Interference with the association of HD2C and the COR gene promoters by HOS15 correlates with increased acetylation levels of histone H3. HOS15 also interacts with CBF transcription factors to modulate cold-induced binding to the COR gene promoters. Our results here demonstrate that cold induces HOS15-mediated chromatin modifications by degrading HD2C. This switches the chromatin structure status and facilitates recruitment of CBFs to the COR gene promoters. This is an apparent requirement to acquire cold tolerance.
| S-EPMC6003311 | biostudies-literature
Project description:Polycomp group (PcG) proteins are members of highly conserved multiprotein complexes, recognized as gene transcriptional repressors during development and shown to play a role in various physiological and pathological processes. PcG proteins consist of two Polycomb repressive complexes (PRCs) with different enzymatic activities: Polycomb repressive complexes 1 (PRC1), a ubiquitin ligase, and Polycomb repressive complexes 2 (PRC2), a histone methyltransferase. Traditionally, PRCs have been described to be associated with transcriptional repression of homeotic genes, as well as gene transcription activating effects. Particularly in cancer, PRCs have been found to misregulate gene expression, not only depending on the function of the whole PRCs, but also through their separate subunits. In this review, we focused especially on the recent findings in the transcriptional regulation of PRCs, the oncogenic and tumor-suppressive roles of PcG proteins, and the research progress of inhibitors targeting PRCs.
| S-EPMC9455514 | biostudies-literature
Project description:A slow cycling, dormant cell state is thought to contribute to the therapeutic resistance of GBM tumour cells, yet not much is known about the biology of this slow-cycling cell population in GBM. By using somatic mouse model of GBM, combined with the inducible H2B-GFP label retention system, we isolated dormant tumour cells from their in vivo niches, and characterised them by single cell RNA sequencing.
2023-04-03 | GSE228785 | GEO
Project description:Catalytically inactive enzyme paralogs occur in many genomes. Some regulate their active counterparts but the structural principles of this regulation remain largely unknown. We report X-ray structures of Trypanosoma brucei S-adenosylmethionine decarboxylase alone and in functional complex with its catalytically dead paralogous partner, prozyme. We show monomeric TbAdoMetDC is inactive because of autoinhibition by its N-terminal sequence. Heterodimerization with prozyme displaces this sequence from the active site through a complex mechanism involving a cis-to-trans proline isomerization, reorganization of a β-sheet, and insertion of the N-terminal α-helix into the heterodimer interface, leading to enzyme activation. We propose that the evolution of this intricate regulatory mechanism was facilitated by the acquisition of the dimerization domain, a single step that can in principle account for the divergence of regulatory schemes in the AdoMetDC enzyme family. These studies elucidate an allosteric mechanism in an enzyme and a plausible scheme by which such complex cooperativity evolved.
| S-EPMC5201418 | biostudies-literature