Project description:Analysis of Histone H3 Lysine 4 mono-, di- and trimethyl and the boundary protein CTCF in CD4+CD25+CD45RA+ regulatory T-cells and conventional CD4+CD25- T-cells. To investigate regulatory functions or potential new transcription start sites in Treg and Tconv cells, we investigated the associated histone modifications. Mono- and dimethylation of histone 3 lysin 4 (H3K4) were previously shown to mark enhancer regions, whereas H3K4 trimethylation generally associates with transcription start sites. At imprinted loci, binding of the insulator protein CTCF, which restricts or directs enhancer-promoter interactions, is often regulated by DNA-methylation. Therefore we performed ChIP-on-chip experiments (chromatin immunoprecipitation followed by microarray hybridization; samples were amplified with ligation mediated PCR [see label protocol for the procedure] prior to labeling) for mono- di- and trimethylation of histone 3 lysin 4 and of CTCF in expanded Treg and Tconv cells. Keywords: ChIP-on-chip ChIP-on-chip experiments for H3K4 mono-, di- and trimethyl and CTCF in CD4+CD25+CD45RA+ regulatory T-cells and conventional CD4+CD25- T-cells were co-hybridizied with the input. Three biologiacal replicates (rep1-3) were performed for every histone mark, two CTCF (rep1 and rep2).
Project description:Analysis of Histone H3 Lysine 4 mono-, di- and trimethyl and the boundary protein CTCF in CD4+CD25+CD45RA+ regulatory T-cells and conventional CD4+CD25- T-cells. To investigate regulatory functions or potential new transcription start sites in Treg and Tconv cells, we investigated the associated histone modifications. Mono- and dimethylation of histone 3 lysin 4 (H3K4) were previously shown to mark enhancer regions, whereas H3K4 trimethylation generally associates with transcription start sites. At imprinted loci, binding of the insulator protein CTCF, which restricts or directs enhancer-promoter interactions, is often regulated by DNA-methylation. Therefore we performed ChIP-on-chip experiments (chromatin immunoprecipitation followed by microarray hybridization; samples were amplified with ligation mediated PCR [see label protocol for the procedure] prior to labeling) for mono- di- and trimethylation of histone 3 lysin 4 and of CTCF in expanded Treg and Tconv cells. Keywords: ChIP-on-chip
Project description:Histone H3K4 methylation is a feature of meiotic recombination hotspots shared by many organisms including plants and mammals. Meiotic recombination is initiated by programmed double strand break (DSB) formation that in budding yeast is directed in gene promoters by histone H3K4 di/trimethylation. This histone modification is indeed recognized by Spp1, a PHD-finger containing protein that belongs to the conserved histone H3K4 methyltransferase Set1 complex. During meiosis, Spp1 binds H3K4me and recruits a DSB protein, Mer2, to promote DSB formation close to gene promoters. How Set1C and Mer2 related functions of Spp1 are connected is not clear.
Project description:These ChIP-seq data files are part of a study where a comparison was made between the change in transcription and H3K4 mono-, di-, and tri-methylation levels in the Arabidopsis thaliana genome when plants are subjected to water deficit stress. Keywords: stress response, histone modification
Project description:To understand the role of LSD1 in regulating histone H3K4 methylation status, ChIP-seq analyse of mono- and di-methylated H3K4 in LSD1-KD HEL cells were performed. The analyses revealed demethylation of H3K4me1 and H3K4me2 by LSD1 at regulatory regions including CEBPA gene enhancer.
Project description:Histone acetylation and methylation regulate gene expression in eukaryotes, but their effects on the transcriptome of a multicellular organism and on the transcriptomic divergence between species are still poorly understood. Here we present the first genome-wide 1-bp resolution maps of histone acetylation, histone methylation and core histone in Arabidopsis thaliana and a comprehensive analysis of these maps and gene expression data in A. thaliana, A. arenosa and allotetraploids. H3K9 acetylation (H3K9ac) and H3K4 trimethylation (H3K4me3) are correlated, and their high densities near transcriptional start sites determine constitutive expression of genes involved in translation. In contrast, broad distributions of these modifications toward coding regions determine expression variation, especially in genes involved in photosynthesis, carbohydrate metabolism, and defense responses. A dispersed distribution of H3K27me3 and depletion of H3K9ac and H3K4me3 are associated with developmentally repressed genes. Finally, genes affected by histone deacetylase mutation and species divergence tend to show high expression variation. In conclusion, changes in histone acetylation and methylation modulate developmental and environmental gene expression variation within and between species.
Project description:Background. Post-translational modifications of histones play important roles in regulating transcription by modulating the structural properties of the chromatin. In plants, methylation of histone H3 lysine4 (H3K4me) is associated with genes and required for normal plant development. Results. We have characterized the genome-wide distribution patterns of mono-, di- and trimethylation of H3K4 (H3K4me1, H3K4me2 and H3K4me3, respectively) in Arabidopsis thaliana using chromatin immunoprecipitation and high-resolution whole-genome tiling microarrays (ChIP-chip). All three types of H3K4me are found to be almost exclusively genic, and two thirds of Arabidopsis genes contain at least one type of H3K4me in seedlings. H3K4me2 and H3K4me3 accumulate predominantly in promoters and 5’ genic regions, whereas H3K4me1 is distributed within transcribed regions. In addition, H3K4me3-containing genes are highly expressed with low levels of tissue specificity, but H3K4me1 or H3K4me2 may not be directly involved in transcriptional activation. Furthermore, a genome-wide preferential co-localization of H3K4me3 and H3K27me3 found in mammals does not appear to exist in plants, but H3K4me2 and H3K27me3 co-localize at a higher-than-expected frequency. Finally, the relationship between H3K4me and DNA methylation was explored by comparing the genome-wide distribution patterns of H3K4me1, H3K4me2 and H3K4me3 in wild type plants and the met1 DNA methyltransferase mutant. Conclusions. H3K4me plays widespread roles in regulating gene expression in plants. Although many aspects of the mechanisms and functions of H3K4me appear to be conserved among all three kingdoms, we observed significant differences in the relationship between H3K4me and transcription or other epigenetic pathways in plants and mammals.