Project description:We investigated the ability of the NFkB protein p65 to bind DNA after RNA digestion. In this ChIP-seq experiment, we investigated the genome-wide binding profiles of p65 in Jurkat cells. We demonstrated that p65 binding to promoters and promoter proximal regions is enhanced by digestion of RNA with RNase A.
Project description:To explore genome-wide alteration of BRD4, MED1, p65 and H3K27Ac during BET inhibition, we performed chromatin immunoprecipitation sequencing (ChIP-seq) of SCC1 cells to examine genome-wide recruitment of the MED1, BRD4, p65 and H3K27ac following JQ1 treatment. BET inhibition by JQ1 led to dramatically loss of the recruitment of MED1, BRD4 and p65 at a cohort of key oncogenes associate with tumorigenesis and metastasis. Suggesting BET inhibition is effective strategy to suppress the tumorigenesis and metastasis of head and neck squamous cell carcinoma.
Project description:Increasing evidence shows that many transcription factors execute important biologic functions independent from their DNA-binding capacity. The NF-κB p65 (RELA) subunit is a central regulator of innate immunity. Here, we investigated the relative functional contribution of p65 DNA-binding and dimerization in p65-deficient human and murine cells reconstituted with single amino acid mutants preventing either DNA-binding (p65 E/I) or dimerization (p65 FL/DD). DNA-binding of p65 was required for RelB-dependent stabilization of the NF-κB p100 protein. The antiapoptotic function of p65 and expression of the majority of TNF-α–induced genes were dependent on p65’s ability to bind DNA and to dimerize. Chromatin immunoprecipitation with massively parallel DNA sequencing experiments revealed that impaired DNA-binding and dimerization strongly diminish the chromatin association of p65. However, there were also p65-independent TNF-α–inducible genes and a subgroup of p65 binding sites still allowed some residual chromatin association of the mutants. These sites were enriched in activator protein 1 (AP-1) binding motifs and showed increased chromatin accessibility and basal transcription. This suggests a mechanism of assisted p65 chromatin association that can be in part facilitated by chromatin priming and cooperativity with other transcription factors such as AP-1.
Project description:In effort to develop methodology for targeted top down mass spectrometry of NF kappa B p65 from human cells, we evaluated the utility of HaloTag for purification and analysis of recombinant protein. During our study, two datasets of bottom up LC-MS/MS were generated: one from in-gel digestion of the predominant band following p65-HaloTag purification, another from in-solution digestion of all the proteins present in a p65-HaloTag purification. p65-HaloTag copurifying proteins identified in our datasets include the known interactors c-Rel, NF-kappaB p105, NF-kappaB p100, and NF-kappaB inhibitor beta. Over 100 proteins were identified by at least two peptides using a Mascot ion cut-off score of 30.
Project description:The inflammatory gene response requires activation of the protein kinase TAK1, but it is currently unknown how TAK1-derived signals coordinate transcriptional programs in the genome. We determined the genome-wide binding of the TAK1-controlled NF-?B subunit p65 in relation to active enhancers and promoters of transcribed genes by ChIP-seq experiments. Out of 35,000 active enhancer regions, 410 H3K4me1-positive enhancers show interleukin (IL)-1-induced H3K27ac and p65 binding. Inhibition of TAK1, IKK2 or depletion of p65 blocked inducible enhancer activation and gene expression. As exemplified by the CXC chemokine cluster located on chromosome 4, the TAK1-p65 pathway also regulates the recruitment kinetics of the histone acetyltransferase CBP, of NF-?B p50 and of AP-1 transcription factors to both, promoters and enhancers. This study provides a high resolution view of epigenetic changes occurring during the IL-1 response and allows the first genome-wide identification of a novel class of inducible p65 NF-?B-dependent enhancers in epithelial cells. RNA-seq of KB cells either untreated or treated with IL-1 alpha
Project description:The inflammatory gene response requires activation of the protein kinase TAK1, but it is currently unknown how TAK1-derived signals coordinate transcriptional programs in the genome. We determined the genome-wide binding of the TAK1-controlled NF-κB subunit p65 in relation to active enhancers and promoters of transcribed genes by ChIP-seq experiments. Out of 35,000 active enhancer regions, 410 H3K4me1-positive enhancers show interleukin (IL)-1-induced H3K27ac and p65 binding. Inhibition of TAK1, IKK2 or depletion of p65 blocked inducible enhancer activation and gene expression. As exemplified by the CXC chemokine cluster located on chromosome 4, the TAK1-p65 pathway also regulates the recruitment kinetics of the histone acetyltransferase CBP, of NF-κB p50 and of AP-1 transcription factors to both, promoters and enhancers. This study provides a high resolution view of epigenetic changes occurring during the IL-1 response and allows the first genome-wide identification of a novel class of inducible p65 NF-κB-dependent enhancers in epithelial cells. ChIP-seq in KB cells with 5 different antibodies under different treatment conditions
Project description:We look at differential gene expression between immortalized p65+/+ and p65-/- MEFs to identify potential NF-kB regulated genes which when grouped based on biological function indicates candidates involved in protecting p65+/+ cells from macrophage-mediated killing
Project description:Two types of RNA:DNA associations can lead to genome instability: the formation of R-loops during transcription and the incorporation of ribonucleotide monophosphates (rNMPs) into DNA during replication. Both ribonuclease (RNase) H1 and RNase H2 degrade the RNA component of R-loops, whereas only RNase H2 can remove one or a few rNMPs from DNA. We performed high-resolution mapping of mitotic recombination events throughout the yeast genome in diploid strains of Saccharomyces cerevisiae lacking RNase H1 (rnh1Δ), RNase H2 (rnh201Δ), or both RNase H1 and RNase H2 (rnh1Δ rnh201Δ). We found little effect on recombination in the rnh1Δ strain, but elevated recombination in both the rnh201Δ and the double-mutant strains; levels of recombination in the double mutant were about 50% higher than in the rnh201 single-mutant strain. An rnh201Δ mutant that additionally contained a mutation that reduces rNMP incorporation by DNA polymerase ε (pol2-M644L) had a level of instability similar to that observed in the presence of wild-type Polε. This result suggests that the elevated recombination observed in the absence of only RNase H2 is primarily a consequence of R loops rather than misincorporated rNMPs.
Project description:The inflammatory gene response requires activation of the protein kinase TAK1, but it is currently unknown how TAK1-derived signals coordinate transcriptional programs in the genome. We determined the genome-wide binding of the TAK1-controlled NF-M-NM-:B subunit p65 in relation to active enhancers and promoters of transcribed genes by ChIP-seq experiments. Out of 35,000 active enhancer regions, 410 H3K4me1-positive enhancers show interleukin (IL)-1-induced H3K27ac and p65 binding. Inhibition of TAK1, IKK2 or depletion of p65 blocked inducible enhancer activation and gene expression. As exemplified by the CXC chemokine cluster located on chromosome 4, the TAK1-p65 pathway also regulates the recruitment kinetics of the histone acetyltransferase CBP, of NF-M-NM-:B p50 and of AP-1 transcription factors to both, promoters and enhancers. This study provides a high resolution view of epigenetic changes occurring during the IL-1 response and allows the first genome-wide identification of a novel class of inducible p65 NF-M-NM-:B-dependent enhancers in epithelial cells. Two sets of experiments were performed as biological replicate series (rep1 and rep2) each comprising of the following 4 conditions: Human epithelial KB cells were 1) left untreated or were 2) treated with Interleukin-1-alpha (10ng/M-BM-5l) for 1 hour, 3) treated for 1.5h with the TAK1 inhibitor 5Z-7-oxozeaenol (1M-BM-5M) or were 4) treated with 5Z-7-oxozeaenol for 30 minutes followed by Interleukin-1-alpha for 1 hour.