During transcription initiation, the TFIIH-kinase Kin28/Cdk7 marks RNA polymerase II (Pol II) by phosphorylating the C-terminal domain (CTD) of its largest subunit. Here we describe a structure-guided chemical approach to covalently and specifically inactivate Kin28 kinase activity in vivo. This method of irreversible inactivation recapitulates both the lethal phenotype and the key molecular signatures that result from genetically disrupting Kin28 function in vivo. Inactivating Kin28 impacts promoter release to differing degrees and reveals a “checkpoint” during the transition to productive elongation. While promoter-proximal pausing is not observed in budding yeast, inhibition of Kin28 attenuates elongation-licensing signals, resulting in Pol II accumulation at the +2 nucleosome and reduced transition to productive elongation. Furthermore, upon inhibition, global stabilization of mRNA masks different degrees of reduction in nascent transcription. This study resolves long-standing controversies on the role of Kin28 in transcription and provides a rational approach to irreversibly inhibit other kinases in vivo. Overall design: Total RNA was collected from wild-type and analog-sensitive Kin28 strains treated with reversible inhibitor 1-NAPP-1, irreversible inhibitor CMK, and solvent control DMSO. Equivalent ratios of S. pombe : S. cerevisiae cells were added to each sample before RNA extraction for normalization of read counts after sequencing. Nascent RNA was purified from total RNA by 4-thiouracil labeling, biotinylation, and streptavidin-pulldown. As a negative control, nascent RNA was also extracted from total RNA from cells that had not been treated with 4-thiouracil.
Engineered Covalent Inactivation of TFIIH-Kinase Reveals an Elongation Checkpoint and Results in Widespread mRNA Stabilization.
Cell line, Treatment, Subject
View SamplesThe inflammatory response depends upon selective, rapid transcription initiation and high-level generation of gene products for defense against pathogens and environmental insult1,2. Kinase cascades are broadly employed for rapid transmission of extracellular information, thereby regulating the cell’s environmental response. These pathways play a prominent role in the inflammatory process. Several kinases directly phosphorylate histone proteins in chromatin, representing a mechanism for the rapid modification of chromatin with the potential to regulate selective transcription responses to environmental cues3-10. However, the molecular functions of specific histone phosphorylation events in transcription are poorly understood. Here, we demonstrate a direct effect of histone H3 phosphorylation at serine 28 (H3S28p) on transcription activation and describe a prominent role for H3S28p in the amplification of inflammatory gene transcription following stimulation of mouse macrophages with bacterial lipopolysaccharide (LPS). We identify MSK kinases as the non-redundant kinases that mediate the rapid, stimulation-dependent deposition of H3S28p on chromatin. Pharmacological approaches, including the use of a novel chemical agent, reveal that MSK inhibition abolishes stimulation-dependent accumulation of H3S28p at LPS-induced genes and reduces production of inflammatory gene products. Mechanistically, H3S28p directly increases transcriptional output by augmenting recruitment of the transcription co-activator and histone acetyltransferase (HAT) p300, and increasing its HAT activity. Our results reveal a delegated role for H3S28p in selective augmentation of transcription during the rapid cellular response to environmental cues. Overall design: Primary mouse bone marrow derived macrophages (BMDM) were used for NGS experiments. Briefly, BMDM were used unstimulated or following stimulation with S. typhosa LPS (100ng/mL) for the indicated period of time. Included in this submission are RNA-seq data for control DMSO treated BMDM (60'' and 120'' LPS stimulation), RMM-64 (5 uM) treated (60’ and 120’), SB747651A (5 uM) treated (60’ and 120’), and C646 (37.5 uM) teated (60’ and 120’). Further, ChIP-seq data for H3S28p time-course in BMDM stimulated with LPS includes one file each for 0’, 30’, 60’, 120’, 180’, 240’, and one file each at 0’ and 30’ for control DMSO treated, RMM-64 treated, SB747651A treated, and C646 treated BMDM. Also provided is an H3K27ac ChIP-seq time course in LPS stimulated BMDM: 0’, 30’, 120’, 180’, 240’.
Chromatin Kinases Act on Transcription Factors and Histone Tails in Regulation of Inducible Transcription.
No sample metadata fields
View SamplesThe myeloma bone marrow microenvironment promotes proliferation of malignant plasma cells and resistance to therapy. Interleukin-6 (IL-6) and downstream JAK/STAT signaling are thought to be central components of these microenvironment-induced phenotypes. In a prior drug repurposing screen, we identified tofacitinib, a pan-JAK inhibitor FDA-approved for rheumatoid arthritis, as an agent that may reverse the tumor-stimulating effects of bone marrow mesenchymal stromal cells. Here, we validated both in vitro, in stromal-responsive human myeloma cell lines, and in vivo, in orthotopic disseminated murine xenograft models of myeloma, that tofacitinib showed both single-agent and combination therapeutic efficacy in myeloma models. Surprisingly, we found that ruxolitinib, an FDA-approved agent targeting JAK1 and JAK2, did not lead to the same anti-myeloma effects. Combination with a novel irreversible JAK3-selective inhibitor also did not enhance ruxolitinib effects. RNA-seq and unbiased phosphoproteomics revealed that marrow stromal cells stimulate a JAK/STAT-mediated proliferative program in myeloma plasma cells, and tofacitinib reversed the large majority of these pro-growth signals. Taken together, our results suggest that tofacitinib specifically reverses the growth-promoting effects of the tumor microenvironment through blocking an IL-6-mediated signaling axis. As tofacitinib is already FDA-approved, these results can be rapidly translated into potential clinical benefits for myeloma patients. Overall design: Single-end 50 bp RNA-seq of MM.1S myeloma cell line either grown alone in monoculture, MM.1S isolated after 24 hr co-culture with immortalized HS5 bone marrow stromal cells, or HS5 bone marrow stromal cells grown alone
Repurposing tofacitinib as an anti-myeloma therapeutic to reverse growth-promoting effects of the bone marrow microenvironment.
Subject
View SamplesWe compared polyIC stimulated cells in the presence of either GFP or NS5 protein Overall design: A549 cells presence with GFP- or NS5-expressing plasmid using Polyjet (Signagen) according to manufacturer instructions, and 30 hours later stimulated with polyIC (Tocris) as previously described (Marazzi et al., 2012). At 12 hours post-stimulation, total cellular RNA was purified by RNeasy column (Qiagen).
Comparative Flavivirus-Host Protein Interaction Mapping Reveals Mechanisms of Dengue and Zika Virus Pathogenesis.
Specimen part, Cell line, Subject
View SamplesBackground
Aberrant mucin assembly in mice causes endoplasmic reticulum stress and spontaneous inflammation resembling ulcerative colitis.
Sex, Age, Specimen part
View SamplesThe Drosophila midgut is an ideal model system to study molecular mechanisms that interfere with the intestinal stem cells’ (ISCs) ability to function in tissue homeostasis. Due to the lack of a combination of molecular markers suitable to isolate ISCs from aged intestines, it has been a major challenge to study endogenous molecular changes of ISCs during aging. Our FACS-based approach using the esg-GAL4, UAS-GFP fly line allowed the isolation of a cell population enriched for ISCs from young and old midguts by their small size, little granularity and low GFP intensity. The isolated ISCs were subsequently used for RNA sequencing to identify endogenous changes in the transcriptome of young versus old ISCs. Overall design: Cell populations enriched for ISCs isolated from young (6-8 days old) and old (59-65 days old) midguts were sorted. Cells from three different batches of young and old midguts were subjected to Next Generation Sequencing using Illumina Genome Analyzer IIx.
Nipped-A regulates intestinal stem cell proliferation in <i>Drosophila</i>.
Age, Specimen part, Subject
View SamplesEpilepsy is a major neurological disorder that affects approximately 1% of the population. The processes that lead to the development of epilepsy (epileptogenesis) are largely unknown. Levetiracetam is a novel antiepileptic drug (AED) that in the kindling model inhibits epileptogenesis in addition to being effective in controlling established epilepsy. The mechanisms of action of levetiracetam as an AED and an antiepileptogenic drug are unknown. By identifying the effect of chronic levetiracetam therapy on gene expression in the brain we hope to be able to identify genes that are involved in epileptogenesis. By comparing the gene expression profiles of levetiracetam and phenytoin treatments, we hope to be able to distinguish between genes that are important for the antiepileptic (anti-seizure) effect and genes that are important for the antiepileptogenic effect of levetiracetam. Phenytoin is a well-established AED; its mechanism of action involves inhibition of sodium channels. In contrast to levetiracetam, available data suggest that phenytoin in certain situations may enhance rather than inhibit the development of epilepsy.
Region-specific changes in gene expression in rat brain after chronic treatment with levetiracetam or phenytoin.
No sample metadata fields
View SamplesThe specific contribution of the two TNF-receptors Tnfr1 and Tnfr2 to TNF-induced inflammation in the glomerulus is unknown. In mice, TNF exposure induces glomerular expression of inflammatory mediators like adhesion molecules and chemokines in vivo, and glomerular accumulation of leukocytes.
Distinct contributions of TNF receptor 1 and 2 to TNF-induced glomerular inflammation in mice.
Specimen part, Treatment
View SamplesWe use gene expression data to provide a three-faceted analysis on the links between molecular subclasses of glioblastima, epithelial-to mesenchymal transition (EMT) and CD133 cell surface protein. The contribution of this paper is three-folded: First, we used a newly identified signature for epithelial-to-mesenchymal transition in human mammary epithelial cells, and demonstrated that genes in this signature have significant overlap with genes differentially expressed in all known GBM subtypes. However, the overlap between the genes up-regulated in the mesenchymal subtype of GBM and in the EMT signature was more significant than other GBM subtypes. Second, we provided evidence that there is a negative correlation between the genetic signature of EMT and that of CD133 cell surface protein, a putative marker for neural stem cells. Third, we studied the correlation between GBM molecular subtypes and the genetic signature of CD133 cell surface protein. We demonstrated that the mesenchymal and neural subtypes of GBM have the strongest correlations with the CD133 genetic signature. While the mesenchymal subtype of GBM demonstrates similarity with the signatures of both EMT and CD133, it also demonstrates some differences with each of these signatures that is partly due to the fact that the signatures of EMT and CD133 are inversely related to each other. Taken together this data sheds light on role of the mesenchymal transition and neural stem cells, and their mutual interaction, in molecular subtypes of glioblastoma multiforme.
Investigating the link between molecular subtypes of glioblastoma, epithelial-mesenchymal transition, and CD133 cell surface protein.
Specimen part
View SamplesThe thyroid hormone receptor (TR) has been proposed to regulate target genes in the absence of triiodothyronine (T3), through the recruitment of the corepressors, NCoR and SMRT. NCoR and SMRT may thus play a key role in both hypothyroidism and resistance to thyroid hormone, though this has never been tested in vivo. To accomplish this we developed mice that express in the liver a NCoR protein (L-NCoRID) that cannot interact with the TR. L-NCoRID mice develop normally, however when made hypothyroid the repression of many positively regulated T3-target genes is abrogated, demonstrating that NCoR plays a specific and sufficient role in repression by the unliganded TR. Remarkably, in the euthyroid state, expression of many T3-targets are also upregulated in L-NCoRID mice, demonstrating that NCoR also determines the magnitude of the response to T3 in euthyroid animals. While positive T3 targets were upregulated in L-NCoRID mice in the hypo and euthyroid state there was less effect seen on negatively regulated T3 target genes. Thus, NCoR is a specific regulator of T3-action in vivo and mediates the activity of the unliganded TR. Furthermore, NCoR may play a key role in determining the differences in individual responses to similar levels of circulating T3.
The nuclear corepressor, NCoR, regulates thyroid hormone action in vivo.
No sample metadata fields
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