Project description:Goals: characterization of the transcription factor Ros1 in Ustilago maydis Methods: generation of deletion mutants, microscopic observations, ectopic expression of ros1, identification of Ros1 regulated genes by RNAseq and ChIP sequencing Results: Ros1 is not involved in plant colonization but is essential to trigger sporogenesis during late stages of infection. Premature expression of ros1 revealed that Ros1 counteracts the b-dependent filamentation program and induces morphological alterations resembling the early steps of sporogenesis. Transcriptional profiling and ChIP seq analyses revealed that Ros1 affects the expression of about 30 % of all U. maydis genes with 40% being direct targets. Cell wall remodeling and plasma membrane modifications are among the processes affected by Ros1 dependent regulation. Interestingly a large number of b-dependent genes including transcription factors and effector genes involved in biotrophy establishment were downregulated by Ros1 while a subset of novel “late effectors” were upregulated. Taken together our results indicate that Ros1 is a master regulator of sporogenesis in U. maydis and that the switch to sporogenesis is accompanied by the differential regulation of 75% of the effector genes. 4 samples were analyzed in triplicate. The first two samples correspond to input and output DNA obtained from ChIP carried out on plant material infected with U. maydis strains expressing Ros1 with an HA tag. The other two other samples correspond to input and output DNA from ChIP carried out on plant material infected with U. maydis strains expressing Ros1 without a tag (control samples).
Project description:The mammalian TET dioxygenases contribute to global waves of DNA demethylation in the zygote and in primordial germ cells, but their involvement during de novo DNA methylation at peri/post-implantation development is unknown. Here, we show novel physiological functions of Tet1 in the pre-primitive streak stage mouse embryo, where it is expressed not only in the primed-state epiblast, but also in the extra-embryonic ectoderm. In the epiblast, Tet1 contributes to DNA methylation patterning, which indirectly results in dominant transcriptional repression involving a Jumonji-family gene Jmjd8. In the extra-embryonic ectoderm, Tet1 suppresses expression of metabolic genes involved in oxidative phosphorylation. These lineage-specific gene repressive functions, involving distinct modes of regulation by DNA methylation, counteract precocious differentiation of the embryo prior to the onset of gastrulation. Such dysregulation in the absence of Tet1 are surprisingly tolerated in an inbred strain but results in full embryonic lethality in non-inbred mice, thus implicating a complex but essential role of Tet1 in normal gestational development.
Project description:Our study reports the first genome-wide atlas of functional nodes that mediate proviral silencing in ESCs. It provides evidences for the comprehensive, interconnected and multi-layered genetic/epigenetic machineries by which ESCs maintain the repressive state of provirus and ERVs. ChIP-seq analysis of Chaf1a, Trim28, Sumo2 and Zfp809 to demonstrate the mechanism of the silencing of Endogenous retroviruses
Project description:For ChIPseq analyses JB1 and UVO151 (JB1 Pcrg:clp1) were transformed with a Cib1-3xHA fusion construct was expressed under control of the endogenous promoter. The fusion construct was integrated at the endogenous locus replacing the native Cib1 gene.
Project description:Methylation of cytosines (5meC) is a widespread heritable DNA modification. During mammalian development, two global demethylation events are followed by waves of de novo DNA methylation. In vivo mechanisms of DNA methylation establishment are largely uncharacterized. Here we use Saccharomyces cerevisiae as a system lacking DNA methylation to define the chromatin features influencing the activity of the murine DNMT3B. Our data demonstrate that DNMT3B and H3K4 methylation are mutually exclusive and that DNMT3B is co-localized with H3K36 methylated regions. In support of this observation, DNA methylation analysis in yeast strains without Set1 and Set2 show an increase of relative 5meC levels at the TSS and a decrease in the gene-body, respectively. We extend our observation to the murine male germline, where H3K4me3 is strongly anti-correlated while H3K36me3 correlates with accelerated DNA methylation. These results show the importance of H3K36 methylation for gene-body DNA methylation in vivo. Yeast ChIP sequencing
Project description:Among the most important regulators of gene expression in bacteria are 'nucleoid-associated proteins'. These proteins alter the topology of the bound DNA by bending, wrapping or bridging it, thus having multiple effects, including transcriptional regulation, on the bacterial cell. Among the best-studied nucleoid proteins are H-NS and Fis, which bind to specific sequences on the DNA. H-NS is a global repressor of gene expression. Fis alters the global conformation of the DNA by introducing branched structures in it; but its effect on gene expression on a genomic scale remains largely unclear.<br><br>Several bacterial transcriptional regulators including H-NS and Fis have been studied using ChIP-chip. However, the higher resolution and dynamic range offered by ChIP-Seq have not been exploited for any bacterial species. By performing ChIP-Seq of these two proteins, we present the first such study in a bacterium. In addition to providing a proof-of-principle for the use of this technology for bacteria, we perform our study at multiple time-points during growth in rich medium, thus generating new insights into how these proteins function under different cellular conditions. Further, by analysing our data in conjunction with newly-generated gene expression and RNA polymerase-chromosome interaction data we provide new interpretation of the genome-scale patterns of the interactions of these proteins to the DNA.
Project description:We used ChIP-seq to map the binding of of C-terminally FLAG3-tagged PhoB to the Escherichia coli K-12 genome during growth in MOPS minimal media with low phosphate or high phosphate (0.2 mM or 1.32 mM, respectively). As a control, we performed ChIP-seq in an untagged strain. We also used ChIP-seq to map Sigma 70 (associates with initiating RNA polymerase) binding across the E. coli K-12 genome in wild-type, ΔphoB, Δhns, and Δhns ΔphoB strains grown in low phosphate medium to determine whether PhoB modulates recruitment of RNA polymerase to promoters and whether this is modulated by H-NS.
Project description:Regulation of gene expression by chromatin modification through methylation of histone lysine residues is a dynamic, reversible process that when deregulated is associated with cancer development. In multiple myeloma, combined inhibition of the histone demethylases JARID1B, UTX and JmjD3 by the small molecule GSK-J4 prevents cellular glutamine utilization leading to amino acids deprivation, activates the integrated stress response via GCN2-dependent ATF4 activation, and induces apoptosis. This response is associated with a profound upregulation of metallothionein genes. Combined with clinical data demonstrating that overexpression of JARID1B is associated with shorter survival in multiple myeloma patients, this study highlights histone demethylases as epigenetic drug targets and places this demethylase inhibitor chemotype as having unique potential relative to established anti-myeloma treatment options. In total there are 7 different samples analyzed and one input control. Treatments are carried out with the demethylase inhibitor (or DMSO as negative control) at 6h and 48h, or with LNA targeting demethylases (or scrambled LNA) at 7 days. A negative control at 0h is included.
Project description:Chromosomal rearrangements involving ETS factors, ERG and ETV1, occur frequently in prostate cancer. How these factors contribute to tumorigenesis and whether they play similar in vivo roles remain elusive. We show that ERG and ETV1 control a common transcriptional network but in an opposing fashion. In mice with ERG or ETV1 targeted to the endogenous Tmprss2 locus, either factors cooperated with Pten-loss, leading to localized cancer, but only ETV1 supported development of advanced adenocarcinoma, likely through enhancement of androgen receptor signaling and steroid biosynthesis. Indeed, ETV1 expression promotes autonomous testosterone production, which may contribute to tumor progression to castration-resistant prostate cancer. Patient data confirmed association of ETV1 expression with aggressive disease. We conclude that despite many shared targets, ERG and ETV1 contribute differently to prostate tumor biology. Hence, prostate cancers with these fusions should be considered as distinct subtypes for patient stratification and therapy. Genomic targets of ERG and ETV1 transcription factors were identified by antibody-mediated and biotin-mediated ChIP-chip in human VCaP and LNCaP cells, respectively.