Cooperative dependencies between mutant oncoproteins and wild-type proteins are critical in cancer pathogenesis and therapy resistance. Although spleen tyrosine kinase (SYK) has been implicated in hematologic malignancies, it is rarely mutated. We used kinase activity profiling to identify collaborators of SYK in acute myeloid leukemia (AML) and determined that FMS-like tyrosine kinase 3 (FLT3) is transactivated by SYK via direct binding. Highly activated SYK is predominantly found in FLT3-ITD positive AML and cooperates with FLT3-ITD to activate MYC transcriptional programs. FLT3-ITD AML cells are more vulnerable to SYK suppression than FLT3 wild-type counterparts. In a FLT3-ITD in vivo model, SYK is indispensable for myeloproliferative disease (MPD) development, and SYK overexpression promotes overt transformation to AML and resistance to FLT3-ITD-targeted therapy.
SYK is a critical regulator of FLT3 in acute myeloid leukemia.
Cell line, Treatment
View SamplesOne clear hallmark of mammalian promoters is the presence of CpG islands (CGIs) at more than two thirds of genes whereas TATA boxes are only present at a minority of promoters. Using genome-wide approaches, we show that GC content and CGIs are major promoter elements in mammalian cells, able to govern open chromatin conformation and support paused transcription. First, we define three classes of promoters with distinct transcriptional directionality and pausing properties which correlate with their GC content. We further analyze the direct influence of GC content on nucleosome positioning and depletion, and show that CGIs correlate with nucleosome depletion both in vivo and in vitro. We also show that transcription is not essential for nucleosome exclusion but influences both a weak +1 and a well-positioned nucleosome at CGI borders. Altogether our data support the idea that CGIs have become an essential feature of promoter structure defining novel regulatory properties in mammals. Overall design: Nucleosome density and positioning were studied by high-throughput sequencing of DNA previously treated with Mnase. In parallel, chIPseq for PolII and H3K27ac were performed in mouse and human with different conditions to assess a potential effect of transcription on nucleosomes properties. To investigate transcription at promoters, we analyzed together with genome-wide Pol II accumulation by ChIP-Seq, paused bidirectional transcripts associated with transcription start sites (TSS RNAs).
CpG islands and GC content dictate nucleosome depletion in a transcription-independent manner at mammalian promoters.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcription-dependent generation of a specialized chromatin structure at the TCRβ locus.
Specimen part
View SamplesWe performed ChIP-Seq for hallmark TFs (Ets1, Runx1), histone modification marks (H3K4me1, H3K4me2, H3K4me3, H3K27me3, H3K36me3), total RNA Pol II, short RNA-Seq as well as nucleosome mapping mainly in murine Rag2 -/- thymocytes. We also performed ChIP-Seq for E47 as well as nucleosome mapping, gene expression microarray analysis in CD4+ CD8+ DP thymocytes. Overall, we find a key role for the transcription factor Ets1, contributing towards alpha beta T cell lineage commitment via differential transactivation of stage-specific genes orchestrated by dynamic, co-association -mediated chromatin remodeling, as well as transcription dependent generation of a specialized chromatin structure at the TCR beta locus. Overall design: Genome-wide analysis via ChIP-Seq for Ets1, Runx1, total RNA Pol II binding, H3K4me1, H3K4me2, H3K4me3, H3K27me3, H3K36me3, short RNA-Seq, Mnase-Seq in murine Rag2 -/- thymocytes, ChIP-Seq for E47, Mnase-Seq and gene expression microarray analysis in DP thymocytes This Series represents ShortRNA-Seq data.
Dynamic recruitment of Ets1 to both nucleosome-occupied and -depleted enhancer regions mediates a transcriptional program switch during early T-cell differentiation.
No sample metadata fields
View SamplesWe performed microarray analysis of gene expression in WT and Ets1-/- CD4+ CD8+ DP thymocytes. Overall, we find that Ets1-/- thymocytes display gene expression signatures closer to previous stages of thymocyte development (e.g. DN3-4) than WT DP cells, suggesting that while these cells do become DP thymocytes in the absence of Ets1, that the latter is required for the upregulation of later T-cell genes and that its presence is required for the downregulation of genes corresponding to earlier and alternative stages of development.
Dynamic recruitment of Ets1 to both nucleosome-occupied and -depleted enhancer regions mediates a transcriptional program switch during early T-cell differentiation.
Specimen part
View SamplesWe performed ChIP-Seq for hallmark TFs (Ets1, Runx1), histone modification marks (H3K4me1, H3K4me2, H3K4me3, H3K27me3, H3K36me3), total RNA Pol II, short RNA-Seq as well as nucleosome mapping mainly in murine Rag2 -/- thymocytes. We also performed ChIP-Seq for E47 as well as nucleosome mapping, gene expression microarray analysis in CD4+ CD8+ DP thymocytes. Overall, we find a key role for the transcription factor Ets1, contributing towards alpha beta T cell lineage commitment via differential transactivation of stage-specific genes orchestrated by dynamic, co-association -mediated chromatin remodeling, as well as transcription dependent generation of a specialized chromatin structure at the TCR beta locus.
Dynamic recruitment of Ets1 to both nucleosome-occupied and -depleted enhancer regions mediates a transcriptional program switch during early T-cell differentiation.
Specimen part
View SamplesRecent studies have revealed a myriad of non-coding transcripts in different organisms. For instances, the presence of short bidirectional transcripts is a hallmark of active promoters in mammals, while upstream non-coding transcripts can be detected at most expressed genes in conditions where the RNA degradation machinery is inhibited. Here, we used RNA-seq with very high sequencing depth to characterize strand specific transcripts from primary mouse tissues. We found that a substantial fraction of gene promoters sustain expression of long non-coding antisense transcripts. These transcripts have an average size of 6 kb, have features of mature transcripts, but remain associated with the chromatin. We named this new class of non-coding RNAs Long Upstream Antisense Transcripts (LUAT). Strikingly, the LUAT and coding gene pairs are usually co-regulated, with the associated genes often/generally coding for transcriptional regulators functioning during development and cell differentiation. Indeed, these bidirectional promoters share several characteristic of developmental gene promoters, including large CpG islands and high degree of conservation, and display symetrical GC skews. Finally, we found that bidirectional promoters have enlarged platforms of Pol II initiation, associated with an intensified rate of early transcriptional elongation. We concluded that promoters of developmental regulators are characterized by a specialized mechanism of Pol II transcription, whereby Pol II poising is directly coupled to relaxed bidirectional transcription. Overall design: Expression of noncoding RNA transcripts in CD4-,CD8- double negative thymocytes from Rag2-/- mice was studied by strand-specific, ribosomal-depleted RNA-seq experiment, using Illumina sequencer
Divergent transcription is associated with promoters of transcriptional regulators.
Specimen part, Cell line, Subject
View SamplesThe host innate immune response is the first line of defense against pathogens and is orchestrated by the concerted expression of genes induced by microbial stimuli. Deregulated expression of these genes is linked to the initiation and progression of numerous diseases associated with exacerbated inflammation. Here, we identify Topoisomerase 1 (Top1) as a critical positive regulator of RNA polymerase II (RNAPII) transcriptional activity at pathogen-induced genes. Notably, depletion or chemical inhibition of Top1 suppresses the host response against replicating Influenza and Ebola viruses as well as bacterial products. As a result, therapeutic pharmacological inhibition of Top1 protects mice from death in experimental models of chemical- and pathogen-induced lethal inflammation. Our results indicate that Top1 inhibition could be used as therapy against life threatening infections characterized by an acutely exacerbated immune response. Overall design: RNA seq was performed on Ebola (Wild type and mutant) infected or uninfected THP-1 cells in the presence of DMSO or Camptothecin
Topoisomerase 1 inhibition suppresses inflammatory genes and protects from death by inflammation.
Specimen part, Treatment, Subject
View SamplesBackground: The ability of an organism to repair damages to DNA is inextricably linked to aging and cancer. We have characterized and compared the transcriptome of C. elegans mutants deficient in DNA base excision repair, nucleotide excision repair or both to elucidate the transcriptional changes incurred by the reduction of these repair pathways.
A two-tiered compensatory response to loss of DNA repair modulates aging and stress response pathways.
No sample metadata fields
View SamplesDuring adipocyte differentiation, significant alternative splicing changes occur in association with the adipogenic process. However, little is known about roles played by splicing factors in this process. We observed that mice deficient for the splicing factor SRSF10 exhibit severely impaired development of subcutaneous white adipose tissue as a result of defects in adipogenic differentiation. To identify splicing events responsible for this, RNA-seq analysis was performed using embryonic fibroblast cells. Several SRSF10-affected splicing events that are implicated in adipogenesis have been identified. Skipping of lipin1 exon 7 is controlled by SRSF10-regulated cis-element located in the constitutive exon 8. The activity of this element depends on the binding of SRSF10 and correlates with the relative abundance of lipin1a mRNA. A series of experiments demonstrated that SRSF10 controls the production of lipin1a and thus promotes adipocyte differentiation. Indeed, lipin1a expression could rescue SRSF10-mediated adipogenic defects. Taken together, our results identify SRSF10 as an essential regulator for adipocyte differentiation and also provide new insights into splicing control by SRSF10 in lipin1 pre-mRNA splicing. Overall design: RNA-seq for wide type (WT) and SRSF10-deficient (KO) mouse MEF cells
SRSF10 regulates alternative splicing and is required for adipocyte differentiation.
No sample metadata fields
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