This SuperSeries is composed of the SubSeries listed below.
Global analysis of the relationship between JIL-1 kinase and transcription.
Specimen part, Cell line
View SamplesPositioned nucleosomes limit the access of proteins to DNA and implement regulatory features encoded in eukaryotic genomes. Here we generated the first genome-wide nucleosome positioning map for Schizosaccharomyces pombe and annotated transcription start and termination sites genome-wide. Using this resource we found surprising differences compared to the nucleosome organization in the distantly related yeast Saccharomyces cerevisiae [the cerevisiae data has been published by others (PMID: 17873876) and the raw data is deposited at ArrayExpress(E-MEXP-1172)]. DNA sequence guides nucleosome positioning differently, e.g., poly(dA:dT) elements are not enriched in S. pombe nucleosome-depleted regions (NDRs). Regular nucleosomal arrays emanate more asymmetrically, i.e., mainly co-directionally with transcription, from promoter NDRs, but promoters harbouring the histone variant H2A.Z show regular arrays also upstream. Regular nucleosome phasing in S. pombe has a very short repeat length of 154 base pairs, and requires a remodeler, Mit1, conserved in humans but not found in S. cerevisiae. Nucleosome positioning mechanisms are evidently not universal but evolutionarily plastic.
Schizosaccharomyces pombe genome-wide nucleosome mapping reveals positioning mechanisms distinct from those of Saccharomyces cerevisiae.
No sample metadata fields
View SamplesISWI is an evolutionary conserved ATPase that catalyzes nucleosome remodeling in several different complexes. Two mammalian ISWI orthologs, SNF2H and SNF2L, have specialized functions despite their high similarity. Due to the lack of reagents the functions of SN2L in human cells had not been established. Newly established specific monoclonal antibodies and selective RNA interference protocols now enabled a comprehensive characterization of loss-of-function phenotypes in human cells. Contrasting earlier results obtained in the mouse model, we found SNF2L broadly expressed in primary human tissues. Depletion of SNF2L in HeLa cells led to enhanced proliferation, morphological alterations and increased migration. These phenomena were explained by transcriptome profiling, which identified SNF2L as a modulator of the Wnt signaling network. The cumulative effects of SNF2L depletion on gene expression portray the cell in a state of activated Wnt signaling characterized by increased proliferation and chemotactic locomotion. High levels of SNF2L expression in normal melanocytes contrast to undetectable expression in malignant melanoma. In summary, our data document an anti-correlation between SNF2L expression and several features characteristic of malignant cells.
Nucleosome remodeler SNF2L suppresses cell proliferation and migration and attenuates Wnt signaling.
Cell line
View SamplesTo get insight in the functional role of EGR2 for Ewing sarcoma, we performed a transcriptional profiling of Ewing sarcoma cells after knockdown of EGR2 and compared the resulting transcriptional signature with that of EWSR1-FLI1-silenced Ewing sarcoma cells. In accordance with the strong EGR2-induction by EWSR1-FLI1, both genes highly significantly overlap in their transcriptional signatures. Gene-set enrichment analyses (GSEA) and DAVID (Database for Annotation, Visualisation and Integrated Discovery) gene ontology analyses indicated a strong impact of EGR2 on cholesterol and lipid biosynthesis resembling its function in orchestrating lipid metabolism of myelinating Schwann cells.
Chimeric EWSR1-FLI1 regulates the Ewing sarcoma susceptibility gene EGR2 via a GGAA microsatellite.
Cell line, Treatment
View SamplesProfiling of changes in steady state RNA levels upon RNAi-mediated knockdown of the chromosomal kinase JIL-1 in Drosophila S2 cells.
Global analysis of the relationship between JIL-1 kinase and transcription.
Specimen part
View SamplesInterleukin-1 receptor associated kinase 1 (IRAK1) is an important component of the IL-1R and TLR signaling pathways, which influence Th cell differentiation. Here, we show that IRAK1 promotes Th17 development by mediating IL-1 induced upregulation of IL-23R and subsequent STAT3 phosphorylation, thus enabling sustained IL-17 production. Moreover, we show that IRAK1 signaling fosters Th1 differentiation by mediating T-bet induction and counteracts Treg generation. Cotransfer experiments revealed that Irak1-deficient CD4+ T cells have a cell-intrinsic defect in generating Th1 and Th17 cells under inflammatory conditions in spleen, mesenteric lymph nodes and colon tissue. Furthermore, IRAK1 expression in T cells was shown to be essential for T cell accumulation in the inflamed intestine and mLNs. Transcriptome analysis ex vivo revealed that IRAK1 promotes T cell activation and induction of gut-homing molecules in a cell-intrinsic manner. Accordingly, Irak1-deficient T cells failed to upregulate surface expression of 47 integrin after transfer into Rag1-/- mice and their ability to induce colitis was greatly impaired. Lack of IRAK1 in recipient mice provided additional protection from colitis. Therefore, IRAK1 plays an important role in intestinal inflammation by mediating T cell activation, differentiation and their accumulation in the gut. Thus, IRAK1 is a promising novel target for therapy of inflammatory bowel diseases.
IRAK1 Drives Intestinal Inflammation by Promoting the Generation of Effector Th Cells with Optimal Gut-Homing Capacity.
No sample metadata fields
View SamplesThis study aimed to explore the role of the Zyxin-related protein TRIP6 (thyroid receptor interacting protein 6) in Ewing's sarcoma (ES). By interrogation of published miccroarray data, we observed that of all seven Zyxin-proteins only TRIP6 is highly overexpressed in ES compared to normal tissues. RNA interference experiments and subsequent microarray and gene-set enrichment analyses indicated that TRIP6 expression is associated wth a pro-proliferative and pro-invasive transcriptional signature. Consistently, functional assays demonstrated that TRIP6 promotes migration, invasion, long-term proliferation and clonogencity of ES cells.
The Zyxin-related protein thyroid receptor interacting protein 6 (TRIP6) is overexpressed in Ewing's sarcoma and promotes migration, invasion and cell growth.
Specimen part, Cell line, Treatment
View SamplesPost-translational modifications (PTMs) of histones exert fundamental roles in regulating gene expression. During development, groups of PTMs are constrained by unknown mechanisms into combinatorial patterns, which facilitate transitions from uncommitted embryonic cells into differentiated somatic cell lineages. Repressive histone modifications such as H3K9me3 or H3K27me3 have been investigated in detail, but the role of H4K20me3 in development is currently unknown. Here we show that Xenopus laevis Suv4-20h1 and h2 histone methyltransferases (HMTases) are essential for induction and differentiation of the neuroectoderm. Morpholino-mediated knockdown of the two HMTases leads to a selective and specific downregulation of genes controlling neural induction, thereby effectively blocking differentiation of the neuroectoderm. Global transcriptome analysis supports the notion that these effects arise from the transcriptional deregulation of specific genes rather than widespread, pleiotropic effects. Interestingly, morphant embryos fail to repress the Oct4-related Xenopus gene Oct-25. We validate Oct-25 as direct target of xSu4-20h enzyme-mediated gene repression, showing by chromatin immunoprecipitaton that it is decorated with the H4K20me3 mark downstream of the promoter in normal, but not in double-morphant, embryos. Since knockdown of Oct-25 protein significantly rescues the neural differentiation defect in xSuv4-20h double-morphant embryos, we conclude that the epistatic relationship between Suv4- 20h enzymes and Oct-25 controls the transit from pluripotent to differentiation-competent neural cells. Consistent with these results in Xenopus, murine Suv4-20h1/h2 double-knockout embryonic stem (DKO ES) cells exhibit increased Oct4 protein levels before and during EB formation, and reveal a compromised and biased capacity for in vitro differentiation, when compared to normal ES cells. Together, these results suggest a regulatory mechanism, conserved between amphibian and mammals, in which H4K20me3-dependent restriction of specific POU-V genes directs cell fate decisions, when embryonic cells exit the pluripotent state.
Suv4-20h histone methyltransferases promote neuroectodermal differentiation by silencing the pluripotency-associated Oct-25 gene.
Specimen part, Treatment
View SamplesMicroRNAs (miRNAs) are expressed from a class of small non-protein coding RNA molecules. Growing evidence shows that miRNAs are potent mediators of post-transcriptional gene silencing and emerged to be critical in the regulation of innate and adaptive immune responses (Ansel KM, Immunol Rev 2013, p5; Baumjohann D, Nature Rev Immunol 2013, p666). MicroRNA-181a (miR-181a) constitutes the most prominently expressed miRNA species in DP thymocytes (Neilson JR, Genes Dev 2007, p578; Kirigin FF, JI 2012, p3257) and has been associated with modulating TCR signal strength via targeting serine/threonine as well as tyrosine phosphatases (Li Q-J, Cell 2007, p147). Consequently, elevated expression of miR-181a results in reduced phosphatase activity and increased TCR signal strength. The effect of aberrant expression of miR-181a on TCR signaling has been already analyzed employing short-term assays and in vitro organ cultures. Our group started to investigate the consequences of miR-181a/b-1 deletion on T cell development in vivo in the steady state. To this end, we developed a new mouse model - miR-181a/b-1 knockout mice (Zietara N et al, PNAS 2013b). During investigations of the immune system of miR-181a/b-1 deficient mice we discovered that these miRNAs are critical for the development of invariant natural killer (NK) T cells. Such cells are known to be selected by a high affinity agonist ligands, thus they are particularly sensitive to the modulation of TCR signaling thresholds, which is achieved by miR-181a/b-1 (Zietara N et al, PNAS 2013b). Furthermore we hypothesized that similar regulation might apply for the other T cell populations selected under high TCR signal strength, like Treg cells. Thus our current research focuses on the role of miR-181a/b-1 during Treg cell development in the thymus as well as on their function in the periphery.
No associated publication
Specimen part
View SamplesNucleosomal incorporation of specialized histone variants is an important mechanism to generate different functional chromatin states. Here we report the identification and characterization of two novel primate-specific histone H3 variants, H3.X and H3.Y. Their mRNAs are found in certain human cell lines, in addition to several normal and malignant human tissues. In keeping with their primate-specificity, H3.X and H3.Y are detected in different brain regions. Transgenic H3.X and H3.Y proteins are stably incorporated into chromatin in a similar fashion to the known H3 variants. Importantly, we demonstrate biochemically and by mass spectrometry that endogenous posttranslationally modified H3.Y protein exists in vivo, and that stress-stimuli, such as starvation and cellular density, increase the abundance of H3.Y-expressing cells. Global transcriptome analysis revealed that knock-down of H3.Y affects cell growth and leads to changes in the expression of many genes involved in cell cycle control. Thus, H3.Y is a novel histone variant involved in the regulation of cellular responses to outside stimuli.
Identification and characterization of two novel primate-specific histone H3 variants, H3.X and H3.Y.
Cell line
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