Genome-wide distribution of the three condensin complexes in C. elegans
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ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
SUBMITTER: Anna-Lena Kranz
PROVIDER: E-GEOD-45678 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:In Caenorhabditis elegans, the dosage compensation complex (DCC) specifically binds to and represses transcription from both X chromosomes in hermaphrodites. The DCC is composed of an X-specific condensin complex that interacts with several proteins. During embryogenesis, DCC starts localizing to the X chromosomes around the 40-cell stage, and is followed by X-enrichment of H4K20me1 between 100-cell to comma stage. Here, we analyzed dosage compensation of the X chromosome between sexes, and the roles of dpy-27 (condensin subunit), dpy-21 (non-condensin DCC member), set-1 (H4K20 monomethylase) and set-4 (H4K20 di-/tri-methylase) in X chromosome repression using mRNA-seq and ChIP-seq analyses across several developmental time points. We found that the DCC starts repressing the X chromosomes by the 40-cell stage, but X-linked transcript levels remain significantly higher in hermaphrodites compared to males through the comma stage of embryogenesis. Dpy-27 and dpy-21 are required for X chromosome repression throughout development, but particularly in early embryos dpy-27 and dpy-21 mutations produced distinct expression changes, suggesting a DCC independent role for dpy-21. We previously hypothesized that the DCC increases H4K20me1 by reducing set-4 activity on the X chromosomes. Accordingly, in the set-4 mutant, H4K20me1 increased more from the autosomes compared to the X, equalizing H4K20me1 level between X and autosomes. H4K20me1 increase on the autosomes led to a slight repression, resulting in a relative effect of X derepression. H4K20me1 depletion in the set-1 mutant showed greater X derepression compared to equalization of H4K20me1 levels between X and autosomes in the set-4 mutant, indicating that H4K20me1 level is important, but X to autosomal balance of H4K20me1 contributes only slightly to X-repression. Thus H4K20me1 by itself is not a downstream effector of the DCC. In summary, X chromosome dosage compensation starts in early embryos as the DCC localizes to the X, and is strengthened in later embryogenesis by H4K20me1. RNA-Seq profiles of C. elegans wild type hermaphrodite, mixed sex, at 5 time points and dpy-27, set-4, dpy-21, set-1 and RNAi at 2-3 time points with 3-4 replicates each. RNA-Seq profiles of C. elegans. Strains are N2 (wild type), BS553 fog-2(oz40) V, CB428 dpy-21(e428) V, MK4 dpy-27(y56) III, MT14911 set-4 (n4600) II, SS1075 set-1(tm1821)/hT2g[bli-4(e937) let-?(q782) qIs48] (I;III). Set-1 collections made as heterozygotes and dpy-27(y56) homozygotes. Spike in RNA-seq libraries have AF16 wild type C. briggsae L1s added at a 1:10 ratio. Timepoints are early embryos (synchronized collection, <40 cells), comma embryos (synchronized early embryos aged for 4 hours), mixed embryos (mixed stage embryos from unsynchronized population), L1 (synchronized L1 larvae), L3 (synchronized L3 larvae), and YA (synchronized young adults, collected before embryos present in hermaphrodite gonad). Biological replicates for each strain/stage listed separately. ChIP-seq profiles of C. elegans DCC subunit dpy-27, H4K20me1 histone modification and RNA pol II large subunit ama-1 in 3-6 replicates from mixed stage (unsynchronized) embryos and synchronized L3 larvae. Corresponding inputs are labelled with "Input_" plus ChIP name.
2015-11-09 | E-GEOD-67650 | biostudies-arrayexpress
Project description:Genome-wide distribution of histone H3K18 and H3K27 acetyltransferases, Crebbp (CBP) and Ep300 (p300), is used to map enhancers and promoters, but whether these elements functionally require CBP/p300 remains largely uncertain. We investigated this relationship by comparing genomic CBP recruitment with gene expression in wild type and CBP/p300 double-knockout fibroblasts. ChIP-seq revealed nearby CBP recruitment for 20 percent of constitutively expressed genes, but surprisingly, three-quarters of these were unaffected or slightly activated by CBP/p300 deletion. Computationally defined enhancer-promoter-units (EPUs) having a CBP peak within two kilobases of the enhancer-like element provided better predictive value, with CBP/p300 deletion attenuating expression of 40 percent of such EPU assigned constitutively expressed genes. We next examined signaling-responsive (Hypoxia Inducible Factor) gene expression and CBP recruitment, and found that 97 percent of inducible genes were within 50 kilobases of an inducible CBP peak, and 70 percent of these required CBP/p300 for full inducible expression. Unexpectedly however, most inducible CBP peaks occurred near signal-nonresponsive genes. eight samples total; Two wild type and two CBP null primary mouse embryonic fibroblast (MEF) lines, each treated with 100uM 2,2-dipyridyl or ethanol vehicle for 2 hours
2014-09-29 | E-GEOD-54453 | biostudies-arrayexpress
Project description:The condensin complex is well known to be essential for correct packaging and segregation of chromosomes during mitosis and meiosis in all eukaryotes. To date, the genome wide location and the nature of condensin binding sites has remained elusive in vertebrate systems. A detailed knowledge of condensin binding sites is essential to understand the as-yet enigmatic function of this complex and to define its greater role in chromosome architecture. To address this, we have used next generation sequencing to map condensin I in chicken DT40 cells. Unexpectedly, we found condensin I binds predominately to promoter sequences in mitotic cells. We also found a striking enrichment at both centromeres and telomeres, highlighting the importance of the complex in chromosome segregation. Taken together, the results show condensin I is largely absent from heterochromatic regions. These results reveal for the first time the condensin I binding sites in the vertebrate genome, and demonstrate the importance of the complex in genome segregation and suggest a novel function in gene regulation. Condensin associated DNA from chicken DT40 cells were affinity purified using streptavidin and deep sequenced by Illumina Hiseq2000
2013-10-03 | E-GEOD-45552 | biostudies-arrayexpress
Project description:ChIP seq of Cfp-1 and H3K4me3 in C. elegans late embryos The coding region of F52B11.1a (cfp-1) was PCR amplified from N2 genomic DNA using Phusion polymerase (Finnzymes) and Gateway cloned into pDONR221. The cfp-1 coding region was then recombined into the MosSCI compatible vector pCFJ201 (which targets Mos site Mos1(cxTi10882) chrIV ) downstream of the dpy-30 promoter and upstream of gfp::tbb-2 3’UTR (Zeiser et al. 2011) to generae strain JA1597 expressing GFP tagged Cfp-1 protein. Late embryos were obtained by aging embryos collected by hypochlorite treatment 3.5 hrs prior to flash freezing in liquid nitrogen. Formaldehyde-fixed chromatin extracts and chromatin immunoprecipitations were as in (Kolasinska-Zwierz et al. 2009) except that DNA was sonicated to a size range of 200-400bp. ChIP assays were performed in 1 ml extract (1 mg protein) in FA buffer with 10 micrograms of anti-GFP rabbit serum (Abcam ab290) and anti-H3K4me3 (Abcam ab8580) individually. DNA sequencing libraries were constructed according using the Illumina Truseq sequencing kit and were sequenced on the Illumina platform.
2014-01-01 | E-GEOD-49870 | biostudies-arrayexpress
Project description:Condensin protein complexes play central roles in the three-dimensional organization of chromosomes during mitotic and meiotic cell divisions. How condensin interacts with its chromatin substrates to promote sister chromatid decatenation and segregation is largely unknown. Previous work suggested that condensin, in addition to encircling chromatin fibers topologically within the large ring-shaped structure formed by its structural maintenance of chromosomes (SMC) and kleisin subunits, contacts DNA directly. Here we describe the discovery of a binding domain for double-stranded DNA helices formed by condensinM-bM-^@M-^Ys HEAT-repeat subunits. Using detailed mapping data of the interfaces between the HEAT-repeat and the kleisin subunits, we generated mutant complexes that lack the Ycg1/CAP-G HEAT-repeat subunit. These tetrameric condensin complexes fail to associate stably with chromosomes in yeast and human cells. We suggest that condensin controls chromosome architecture by stabilizing chromatin loops of chromatin fibers through interaction with its unconventional HEAT-repeat DNA binding domain. Analysis of condensin binding genomewide in a wild type and a condensin mutant
2014-05-16 | E-GEOD-55948 | biostudies-arrayexpress
Project description:The experiment was performed to assess the importance of nucleosome eviction for the binding of condensin to chromatin during mitosis. The condensin complex associates with chromatin during mitosis to ensure chromosome condensation and accurate segregation, but how this binding is achieved remains poorly understood. Our study indicates that transcription co-activators Gcn5 and Mst2 assist condensin binding during mitosis by evicting nucleosomes. To reach this conclusion, we mapped nucleosomes, during mitosis, in wild-type and gcn5mst2 mutant strains. This experiment allowed us (1) to identify nucleosome-depleted regions (ndrs) during mitosis and to show that condensin tends to colocalize with ndr at the 3ends of genes, and (2) to confirm the importance of nucleosome eviction from ndrs by gcn5 and mst2, during mitosis, for the binding of condensin to chromatin.this experiment determines the patterns of nucleosomes in wild type and mutant fission yeast cells arrested in early mitosis. We analysed wild-type cells, cells lacking Gcn5 histone acetylatransferase (gcn5D) and cells lacking both Gcn5 and Mst2 histone acetyltransferases (Gcn5Dmst2D). All cells used in this study expressed a GFP-tagged version of condensin (Cnd2-GFP) and were blocked in early mitosis at 19C by the nda3-KM311 mutation. Mitotic indexes were determined by scoring the accumulation of Cnd2-GFP in the nucleus. Mitotic cells were collected and chromatin was digested by increasing amount of MNase to produce mononucleosomes. Mononucleosomal DNA was purified on an agarose gel and sequence on an Illumina Nextseq 500 apparatus. Three replicates of wild type, gcn5D and gcn5Dmst2D were analysed. Nucleosome patterns were determined in wild-type cells, cells lacking Gcn5 and cells lacking both Gcn5 and Mst2.
2016-04-18 | E-MTAB-4620 | biostudies-arrayexpress
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2012-12-01 | E-GEOD-41440 | biostudies-arrayexpress
Project description:We map the genome-wide binding profiles for dTFIIIC220, as well as the Drosophila cohesin and condensin complexes in the late-stage embryonic cell line Kc167 Examination of several proteins in the Kc167 cell line
2014-05-14 | E-GEOD-54529 | biostudies-arrayexpress
Project description:Malignant gliomas constitute one of the most significant areas of unmet medical need, due to the invariable failure of surgical eradication and their marked molecular heterogeneity. Accumulating evidence has revealed a critical contribution by the Polycomb axis of epigenetic repression. However, a coherent understanding of the regulatory networks affected by Polycomb during gliomagenesis is still lacking. Here we integrate transcriptomic and epigenomic analyses to define Polycomb-dependent networks that promote gliomagenesis, validating them both in two independent mouse models and in a large cohort of human samples. We found that Polycomb dysregulation in gliomagenesis affects transcriptional networks associated to invasiveness and de-differentiation. The dissection of these networks uncovers Zfp423 as a crtitical Polycomb-dependent transcription factor whose silencing negatively impacts survival. The anti-gliomagenic activity of Zfp423 requires interaction with the SMAD proteins within the BMP signaling pathway, pointing to a novel synergic circuit through which Polycomb inhibits BMP signaling. Analysis of H3K27me3 distribition in two different stages of gliomagenesis
2016-03-02 | E-GEOD-76289 | biostudies-arrayexpress
Project description:In response to genotoxic stress the TP53 tumour suppressor activates target gene expression to induce cell cycle arrest or apoptosis depending on the extent of DNA damage. These canonical activities can be repressed by TP63 in normal stratifying epithelia to maintain proliferative capacity or drive proliferation of squamous cell carcinomas, where TP63 is frequently overexpressed/amplified. Here we use ChIP-sequencing, integrated with microarray analysis, to define the genome wide interplay between TP53 and TP63 in response to genotoxic stress in normal cells. We reveal that TP53 and TP63 bind to overlapping, but distinct cistromes of sites through utilization of distinctive consensus motifs and that TP53 is constitutively bound to a number of sites. We demonstrate that cisplatin and adriamycin elicit distinct effects on TP53 and TP63 binding events, through which TP53 can induce or repress transcription of an extensive network of genes by direct binding and/or modulation of TP63 activity. Collectively, this results in a global TP53 dependent repression of cell cycle progression, mitosis and DNA damage repair concomitant with activation of anti-proliferative and pro-apoptotic canonical target genes. Further analyses reveals that in the absence of genotoxic stress TP63 plays an important role in maintaining expression of DNA repair genes, loss of which results in defective repair Examination of p63 and p53 binding sites in neonatal foreskin keratinocytes in response to adriamycin or cisplatin treatment
2014-04-11 | E-GEOD-56674 | biostudies-arrayexpress