Project description:In many cancers, critical oncogenes are driven from large regulatory elements, called super-enhancers, which recruit much of the cellM-bM-^@M-^Ys transcriptional apparatus and are defined by extensive H3K27 acetylation. We found that in T-cell acute lymphoblastic leukemia (T-ALL), somatic heterozygous mutations introduce MYB binding motifs in a precise noncoding site, which nucleate a super-enhancer upstream of the TAL1 oncogene. Further analysis of genome-wide binding identified MYB and its histone acetylase binding partner CBP as core components of the TAL1 complex and of the TAL1-mediated feed-forward auto-regulatory loop that drives T-ALL. Furthermore, MYB and CBP occupy endogenous MYB binding sites in the majority of super-enhancer sites found in T-ALL cells. Thus, our study reveals a new mechanism for the generation of super-enhancers in malignant cells involving the introduction of somatic indel mutations within non-coding sequences, which introduce aberrant binding sites for the MYB master transcription factor. ChIP-Seq for transcription factors and co-factors in T cell acute lymphoblastic leukemia cell lines
Project description:H3K79 dimethylation is a mark of transcriptional elongation. To gain insight into the set of genes actively transcribed in MEFs, chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq) was performed to determine the presence of H3K79me2 across the genome. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. ChIP was performed using an antibody against H3K79me2.
Project description:RNA Polymerase II is the enzyme responsible for active transcription. To gain insight into the genes occupied by RNA Polymerase II and actively transcribed in MEFS, chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq) was performed to determine the genome-wide binding targets of RNA Pol2. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. ChIP was performed using an antibody against RNA Polymerase II.
Project description:An ability to map the global interactions of a chemical entity with chromatin genome-wide could provide new insights into the mechanisms by which a small molecule perturbs cellular functions. we developed a method that uses chemical derivatives and massively parallel DNA sequencing (Chem-Seq) to identify the sites bound by small chemical molecules throughout the human genome. We developed in vivo and in vitro Chem-Seq protocols with a biotinylated derivative of small molecules. In the in vivo protocol, Cells were first treated with biotinylated ligand and cross-linked with formaldehyde at the same time. Cells were then lysed, sonicated to shear the DNA, and streptavidin beads were used to isolate biotinylated ligand and associated chromatin fragments. We then used massively parallel sequencing to identify the enriched DNA fragments, and mapped these sequences to the genome. In in vitrol protocol, MM1.S cells were fixed and the derived sonicated lysate incubated with biotinylated drug to enrich for bound chromatin regions in vitro. We then used massively parallel sequencing to identify the enriched DNA fragments, and mapped these sequences to the genome.
Project description:Condensin molecules are loaded onto the genome to mediate essential changes in chromosome condensation during mitosis, but it is not clear why there are two forms of vertebrate condensin that become differentially distributed on chromosomes. We report here that condensin II, the form of condensin present in the nucleus throughout the cell cycle, functions specifically at active genes. Condensin II is loaded at transcriptionally active promoters in embryonic stem cells (ESCs), migrates through these genes in a transcription-dependent fashion and accumulates in transcription termination regions. Unlike cohesin, which is also loaded at active promoters, condensin II has little influence on transcription. We conclude that condensin II is loaded and distributed across actively transcribed chromatin and thus serves to specifically condense this euchromatic portion of chromosomes during the cell division cycle. ChIP-Seq data for Condensin II and Cohesin in v6.5 ESCs treated or not with the RNA polymerase II elongation inhibitor flavopiridol.
Project description:Three transcriptional states can be defined by histone modifications and RNA polymerase II enriched at promoters and across the body of genes. To gain insight into the active, poised and silent genes in human T-ALL cells, two antibodies against RNAP2, and antibodies against H3K4me3, H3K79me2, and H3K27me3 were used for chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq). Genomic DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. ChIP was performed using an antibody against RNAP2, H3K4me3, H3K79me2, and H3K27me3 using whole cell extract (WCE) as a background control. ChIP was performed using a two antibody against hypophosphorylated forms of RNAP2 in two biological replicates. All other ChIPs were done in biological replicates with a single lane of sequencing.
Project description:The oncogenic transcription factor TAL1/SCL is aberrantly expressed in over 40% of cases of T-cell acute lymphoblastic leukemia (T-ALL), emphasizing its importance in the molecular pathogenesis of T-ALL. Here we identify the core transcriptional regulatory circuit controlled by TAL1 and its regulatory partners HEB, E2A, LMO1, LMO2, GATA3 and RUNX1 in T-ALL cells. We show that TAL1 forms an interconnected auto-regulatory loop with its partners, and that the TAL1 complex directly activates the MYB oncogene, forming a feed-forward positive regulatory loop that further promotes the TAL1-regulated oncogenic program. one of the cirtical downstream targets in this circuitry is the TRIB2 gene, which is oppositely regulated by TAL1 and HEB/E2A, and is essential for the survival of T-ALL cells. Human T-ALL cells were cross-linked with formaldehyde for 20 min. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. A sample of whole cell extract (WCE) was sequenced and used as the background to determine enrichment. ChIP was performed using an antibody against total TAL1 (Santa Cruz SC-12984), TCF12/HEB (Santa Cruz SC-357),TCF3/E2A (Santa Cruz SC-349X), LMO1 (Santa Cruz SC-10494), LMO2 (R&D AF2726),GATA3 (Santa Cruz SC-22206) and RUNX1 (Santa Cruz SC-8563). This represents the ChIP-seq portion of this dataset.
Project description:The TATA binding protein (TBP) is a transcription factor that binds specifically to a DNA sequence called the TATA box upstream of the transcription start site. To gain insight into the genes occupied by TBP, chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq) was performed to determine the genome-wide binding targets. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. ChIP was performed using an antibody against TBP.
Project description:Multiple protein complexes and histone marks have been implicated and/or associated with gene repression in ES cells. To gain insights into repressive complexes present at repressed genes and their associated chromatin state, we profiled REST, MCAF1, Ring1b and H4K20me3 in mouse ES cells. DNA was enriched by chromatin immunoprecipitation (ChIP) and analyzed by Solexa sequencing. ChIP was performed using an antibody against REST, MCAF1, Ring1b and H4K20me3.
Project description:Post-translational modification of histones are coupled to transcription where certain modifications are indicative of an active or inactive region of the genome. Additionally, protein complexes can regulate the placement of nucleosomes across the genome and this influences the ability of DNA-binding proteins to interact with regions of the genome. The datasets presented here are ChIP-seq datasets for chromatin modifications associated with active or poised genes (H2Bub, H3K9,K14Ac and H3K4me3). Brg1 is a subunit of the SWI/SNF chromatin remodeling complex. An antibody specific to the chromatin modification or indicated factor was used to enrich for DNA fragments in murine embryonic stem cells. DNA was purified and prepared for Illumina/Solexa sequencing following their standard protocol.