Project description:Nuclear factor kappa B (NF-κB) is a central regulator of inflammation, infection, and immunity pathways and is often dysregulated in autoimmune diseases, inflammatory disorders, and cancers. However, the mechanisms by which different stimuli, including cellular metabolism, modulate NF-κB activation remain unclear. Here, we report that RelA ( p65), a major component of NF-κB, is S-palmitoylated at cysteine 197 and 206 by directly reacting with palmitoyl-CoA. Autopalmitoylation of p65 promotes its nuclear localization and p65-p50 complex formation, thereby enhancing NF-κB transcriptional activities. Furthermore, p65 palmitoylation upregulates RelB expression and promotes non-canonical NF-κB complex formation, further amplifying pathway activation. We also demonstrate that a high-fat diet could enhance p65 palmitoylation and correlate with an increased cytokine production in mouse tissues. These results reveal that lipid metabolism might directly regulate NF-κB activity and suggest that targeting p65 auto-palmitoylation could be a potential therapeutic strategy for diseases with deregulated NF-κB pathway.
Project description:Chromatin immunoprecipitation sequencing (ChIP-seq) was performed to analyze the effect of telomerase inhibition on TNFM-NM-1-induced genome-wide p65 binding in HeLa cells. By obtaining over 40 million uniquely mappable reads per sample from ChIP-seq, maps for TNFM-NM-1-induced p65 binding in absence and presence of an hTERT inhibitor, MST-312, were generated. As expected, TNFM-NM-1 treatment significantly increased genome-wide p65 occupancy. Interestingly, when cells were treated with MST-312 prior to TNFM-NM-1 stimulation, the number of p65 binding sites was reduced. In addition, some binding sites, including important p65 targets like IL6 and TNF, showed a reduced p65 occupancy with a minimum fold change of 1.5, after MST-312 exposure. Taken together, our ChIP-seq data indicate that telomerase is required for optimal p65 binding at a small proportion of p65 target sites upon inflammatory stimuli. Examination of p65 binding in HeLa cells in absence and presence of TNFM-NM-1 and MST-312.
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: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:Effects of p65 palmitoylation on gene expression when overexpressing vector or p65 WT or p65 2CS in p65 knockout 293A cells combined with TNFα treatment
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:Chromatin immunoprecipitation sequencing (ChIP-seq) was performed to analyze the effect of telomerase inhibition on TNFα-induced genome-wide p65 binding in HeLa cells. By obtaining over 40 million uniquely mappable reads per sample from ChIP-seq, maps for TNFα-induced p65 binding in absence and presence of an hTERT inhibitor, MST-312, were generated. As expected, TNFα treatment significantly increased genome-wide p65 occupancy. Interestingly, when cells were treated with MST-312 prior to TNFα stimulation, the number of p65 binding sites was reduced. In addition, some binding sites, including important p65 targets like IL6 and TNF, showed a reduced p65 occupancy with a minimum fold change of 1.5, after MST-312 exposure. Taken together, our ChIP-seq data indicate that telomerase is required for optimal p65 binding at a small proportion of p65 target sites upon inflammatory stimuli.
Project description:Inflammation is involved in both initiation and promotion of colorectal cancer (CRC), and patients with inflammatory bowel disease (IBC) have increased risk of developing CRC. Tumor necrosis factor alpha (TNFα) is a cytokine secreted by e.g. macrophages, and this signaling is deregulated in IBD and CRC. TNFα activates the pro-survival transcription factor complex NFκB, which is composed of several subunits including p65 (RELA). We recently characterized the genome-wide transcriptional impact by TNFα in two CRC cell lines, but how p65 binds the chromatin, its cistrome, in colorectal cancer cells has not been explored. We here used p65 chromatin immunoprecipitation followed by sequencing (ChIP-Seq) in HT29 and SW480 cells, and correlated with the transcriptomic impact of TNFα. Further, estrogen receptor beta (ERβ) has anti-inflammatory and anti-tumorigenic effects in colon cells and interacts with NFκB main targets. We have shown that ERβ impacts TNFα signaling in CRC cells and ERβ impacts the P65 cistrome.
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:TNF alpha is one of the inflammatory mediator and induce genes mainly by transcriptional factor, p65, in endothelial cells. This time, we performed a time course study to detect the change of localization of p65 and Pol II. To identify p65 and Pol II binding sites, we used chromatin immunoprecipitation with deep sequencing (ChIP-seq) of HUVECs treated with or without TNF alpha for 30 mins. Cells were starved before stimulation longer than 16 hours. HUVECs were used within the first 6 passages. For crosslinking, 10 mM of EGS in 50% glacial acetic acid was used for 45 min, followed by 20 min of 1% paraformaldehyde treatmet was used.