ChIPseq of DDX3X, DDX54, ERalpha and H3K4me3 in human breast cancer MCF7 cells
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ABSTRACT: We aimed to investigate the chromatin binding activity of DDX3X and DDX54 RNA helicases in human ER -dependent breast cancer MCF7 cells. We run a parallel chromatin binding profiling of ER ChIP-seq. H3K4me3 profiling was used as a quality control of the ChIP-seq procedure.
Project description:Regulation of Megakaryocytic differentiation in Cell Line Models by Dynamic Combinatorial Interactions of RUNX1 with Its Cooperating Partners Examination of RUNX1 binding in K562 cells, before and following TPA induction and CMK cells. Examination of GATA1 and FOS binding and H3K4me1 and H3K27me3 modification levels following TPA induction in K562 cells.
Project description:ChIP-seq to define bindings sites for TBX2, MYCN, H3K27ac, H3K4me1, H3K4me3 and Input in the cell lines IMR-32, CLB-GA, NGP, IMR-5/75, GI-M-EN, CHP-212, and IMR-5.
Project description:Glioblastomas (GBM) harbor subpopulations of therapy-resistant tumor initiating cells (TICs) that are self-renewing and multipotent. To understand the regulation of the TIC state, we performed an image-based screen for genes regulating GBM TIC maintenance and identified ZFHX4, a 397-kDa transcription factor. ZFHX4 is required to maintain TIC-associated phenotypes in vitro, suggesting that ZFHX4 regulates TIC differentiation, and its suppression increases glioma-free survival in intracranial xenografts. ZFHX4 interacts with CHD4, a core member of the NuRD (nucleosome remodeling and deacetylase) complex. ZFHX4 and CHD4 bind to overlapping sets of genomic loci and control similar gene expression programs. Using expression data derived from GBM patients, we demonstrate ZFHX4 is a master regulator of CHD4-mediated gene expression. These observations define ZFHX4 as a regulatory factor that links the chromatin remodeling NuRD complex and the GBM TIC state. Examination of binding of ZFHX4 and CHD4 across the human genome, using the 0308 tumor initiating cell line. Two replicates for each protein, compared to whole cell extract inputs.
Project description:This SuperSeries is composed of the following subset Series: GSE24777: Regulation of Megakaryocytic differentiation in Cell Line Models by Dynamic Combinatorial Interactions of RUNX1 with Its Cooperating Partners GSE24778: Expresssion data in K562 cells, before and after TPA induction and including a RUNX1 knockout construct or a control structure Refer to individual Series
Project description:The piRNA-interacting Piwi protein is involved in transcriptional silencing of transposable elements in ovaries of D. melanogaster. Here we characterized the genome-wide effect of nuclear Piwi elimination on the presence of the heterochromatic H3K9me3 mark and HP1a, as well as on the transcription-associated mark H3K4me2. Our results demonstrate that a significant increase in the H3K4me2 level upon nuclear Piwi loss is not accompanied by the alterations in H3K9me3 and HP1a levels for several germline-expressed transposons, suggesting that in this case Piwi prevents transcription by a mechanism distinct from H3K9 methylation. We found that the targets of Piwi-dependent chromatin repression are mainly related to the elements that display a higher level of H3K4me2 modification in the absence of silencing, i.e. most actively transcribed elements. We also show that Piwi-guided silencing does not significantly influence the chromatin state of dual-strand piRNA-producing clusters. In addition, host protein-coding gene expression is essentially not affected due to the nuclear Piwi elimination, but we noted an increase in small nuclear spliceosomal RNAs abundance and propose Piwi involvement in their posttranscriptional regulation. Our work reveals new aspects of transposon silencing in Drosophila, indicating that transcription of transposons can underpin their Piwi dependent silencing, while canonical heterochromatin marks are not obligatory for their repression. Examination of histone modifications in ovaries from two different fly lines- piwiNt/piwi2 (mutant) and piwi/+ (wildtype)
Project description:This SuperSeries is composed of the following subset Series: GSE22343: ChIP-chip of siGFP- or siHOTAIR-treated foreskin fibroblasts with anti-H3K4me2, anti-LSD1 or anti-SUZ12 antibodies on HOX tiling array GSE22344: ChIP-chip of siGFP- or siHOTAIR-treated foreskin fibroblasts with anti-LSD1 or anti-SUZ12 antibodies on human HG18 Nimblegen promoter arrays Refer to individual Series
Project description:We previously demonstrated by genomic and bioinformatical approaches that human macrophage (MΦ) activation is best described by a spectrum model (Xue et al, Immunity, 2014). MΦ integrate exogenous input signals on transcriptional level in a unique fashion to generate specific functional programs, enabling the plasticity in disease-related pathophysiologies. Such versatile responsiveness requires fast changes of transcription mediated by transcriptional regulators (TRs) or epigenomic changes. To better understand the principles of this regulation during human MΦ activation, we assessed histone modifications including H3K4me1, H3K4me3, H3K27me3, and H3K27Ac by ChIP-sequencing allowing us to characterize the functional state of promoters (active, poised, repressed) and enhancers (active, inactive, intermediate). Using transcriptome data from our MΦ spectrum model, we generated a co-regulation network of all TRs. Next, we overlaid epigenomic information and transcriptional changes of major TRs over time onto the TR network. We observed that input signals like IFNγ or TNFα induce a specific network of TRs that are transcriptionally regulated themselves, the combination of regulated TRs changes over time with a boost of transcriptional regulation of dozens of TRs 4 to 12 hrs post input signal exposure, almost all TRs within the network show active promoters, even if the TR itself is not expressed, and similar results are obtained for enhancers with open or at least intermediated states. These findings strongly suggest that in MΦ, the TR-defined cellular â??switch panelâ?? is always accessible thereby allowing MΦ to quickly respond to the diverse input signal repertoire from the environment. Epigenetic analysis of promoter and enhancer sites in primary human macrophage subtypes and correlation to RNA-seq expression data
Project description:Global regulation of H2A.Z localization by the INO80 chromatin remodeling enzyme is essential for genome integrity. Chromatin immunoprecipitation (ChIP) of Htz1 in wild-type and ino80 mutant yeast demonstrated that Ino80 plays a role in replacing Htz1 with H2A. Comparison of Htz1 localization in wt vs ino80 mutant yeast Prior to immunoprecipitation, cells arrested with alpha-factor or nocodazole: - The alpha-factor mating pheromone arrests yeast of the a mating type in the G1 phase of the cell cycle. - Nocodazole disrupts the polymerization of microtubules, blocking the cells from entering mitosis and arresting them in the G2/M phase of the cell cycle.
Project description:Transcription of the >200 rRNA genes (rDNA) by RNA Polymerase I (RPI) determines as much as 35% of total nuclear RNA synthesis and is a major determinant of cell growth implicated in a range of hypertrophic and developmental disorders. Activation of the rDNA involves the formation of an extended nucleosome free region (NFR) by the multi-HMGbox factor UBTF, which is also implicated with the RPI specific TBP-TAFI factor SL1 in preinitiation complex formation. However, neither factor alone displays significant DNA sequence binding specificity. Here we show that in cell cooperation between SL1 and the UBTF1 splice variant creates the sequence specificity required for promoter recognition. While both UBTF1 and UBTF2 splice variants bind throughout the rDNA NFR, only UBTF1 binds at the rDNA promoters. Conditional deletion of the Taf1b subunit of SL1 depleted UBTF1 from the rDNA promoters but not from elsewhere across the rDNA NFR. We show RPI promoters are particularly poor binding sites for UBTF and suggest an induced-fit model in which promoter-specific remodelling by UBTF1 creates high affinity sites for SL1 binding. A mouse model of the UBTF-E210K pediatric neurodegeneration syndrome suggests this mutation affects cooperativity of UBTF-SL1 promoter recruitment and further supports the induced-fit model.
Project description:Long intergenic noncoding RNAs (lincRNAs) regulate chromatin states and epigenetic inheritance. Here we show that the lincRNA HOTAIR serves as a scaffold for at least two distinct histone modification complexes. A 5’ domain of HOTAIR binds Polycomb Repressive Complex 2 (PRC2) while a 3’ domain of HOTAIR binds the LSD1/CoREST/REST complex. The ability to tether two distinct complexes enables RNA-mediated assembly of PRC2 and LSD1, and coordinates targeting of PRC2 and LSD1 to chromatin for coupled histone H3 lysine 27 methylation and lysine 4 demethylation. Our results suggest that lincRNAs may serve as scaffolds by providing binding surfaces to assemble select histone modification enzymes, and thereby specify the pattern of histone modifications on target genes. Coordinate loss of SUZ12 and LSD1 occupancy caused by HOTAIR knockdown were concentrated in proximal promoters of HOXD genes. These regions correspondingly lost H3K27me3 and gained H3K4me2, the respective histone methylation products of PRC2 and LSD1 complexes. Comparison occupancy of LSD1 and SUZ12 of siGFP and siHOTAIR foreskin fibroblasts on HOX tiling array. Human foreskin fibroblasts were transfected with siGFP or siHOTAIR. The cells were harvested and ChIP analysis with anti-H3K4me2, anti-LSD1 and anti-SUZ12 antibodies was performed.