Genome-wide identification of PPARG binding sites in NCI-H2347 and NCI-H1993 cell lines
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Ralf Kittler
PROVIDER: E-GEOD-58382 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Identification and characterization of HP1BP3 (a human histone H1 homologue) as a novel chromatin retention factor essential for the co-transcriptional processing of pri-miRNA. We generated BAC transgenic cells at 80% confluency (~1x107) were cross-linked with 1% formaldehyde for 10 minutes at 37°C, and quenched with 125 mM glycine at room temperature for 5 minutes. The fixed cells were washed twice with cold PBS, scraped, and transferred into 1 ml PBS containing protease inhibitors (Roche). After centrifugation at 700 g for 4 minutes at 4°C, the cell pellets were resuspended in 100 μl ChIP lysis buffer (1% SDS, 10 mM EDTA, 50 mM Tris-HCl [pH 8.1] with protease inhibitors) and sonicated at 4°C with a Bioruptor (Diagenode) (30 seconds ON and 30 seconds OFF at highest power for 15 minutes). The sheared chromatin with a fragment length of ~200 â 600 bp) was centrifuged at 20,000 g for 15 minutes at 4°C). 100 μl of the supernatant was used for ChIP or as input. A 1:10 dilution of the solubilized chromatin in ChIP dilution buffer (0.01% SDS, 1.1% Triton X-100, 1.2 mM EDTA, 167 mM NaCl 16.7 mM Tris-HCl [pH 8.1]) was incubated at 4°C overnight with 6 μg/ml of a goat anti-GFP (raised against His-tagged full-length eGFP and affinity-purified with GST-tagged full-length eGFP). Immunoprecipitation was carried out by incubating with 40 μl pre-cleared Protein G Sepharose beads (Amersham Bioscience) for 1 hour at 4°C, followed by five washes for 10 minutes with 1ml of the following buffers: Buffer I: 0.1% SDS, 1% Triton X-100, 2 mM EDTA, 20 mM Tris-HCl [pH 8.1], 150 mM NaCl; Buffer II: 0.1% SDS, 1% Triton X-100, 2 mM EDTA, 20 mM Tris-HCl [pH 8.1], 500 mM NaCl; Buffer III: 0.25 M LiCl, 1% NP-40, 1% deoxycholate, 1 mM EDTA, 10 mM Tris-HCl [pH 8.1]; twice with TE buffer [pH 8.0]. Elution from the beads was performed twice with 100 μl ChIP elution buffer (1% SDS, 0.1 M NaHCO3) at room temperature (RT) for 15 minutes. Protein-DNA complexes were de-crosslinked by heating at 65°C in 192 mM NaCl for 16 hours. DNA fragments were purified using QiaQuick PCR Purification kit (QIAGEN) and eluted into 30 μl H2O according to the manufacturerâs protocol after treatment with RNase A and Proteinase K.
2016-07-24 | E-GEOD-77854 | biostudies-arrayexpress
Project description:Polycomb repressive complex-2 (PRC2) is a histone methyltransferase required for epigenetic silencing during development and cancer. Long non-coding RNAs (lncRNAs) recruit PRC2 to chromatin, but the general role of RNA in maintaining repressed chromatin is unknown. ChIP-seq, combined with RNA-seq, indicating that PRC2 is also associated with active genes, but most of these are not regulated by PRC2. These results were complemented by in vitro binding assays measuring the binding constant of human PRC2 to various RNAs and find comparable affinity for human lncRNAs targeted by PRC2 and irrelevant transcripts from ciliates and bacteria. PRC2 binding is size-dependent, with lower affinity for shorter RNAs. These findings support a model in which promiscuous binding of PRC2 to RNA transcripts allows it to scan for target genes that have escaped repression, leading to maintenance of the repressed state. Such RNAs may also provide a decoy for PRC2. Cell culture: HEK293T/17 cells were cultured in DMEM with 10% FBS for no longer than 15 passages. ON-TARGETplus SMARTpool for human SUZ12 (Thermo Scientific, Dharmacon cat # L-006957-00-0005) was used to knockdown SUZ12 (siSUZ12) and ON-TARGETplus Non-targeting Pool (Dharmacon cat # D-001810-10-05) was used as a negative control (siCtrl). A total of 25 nM siRNA was transfected in 6-well dishes using LipofectamineM-bM-^DM-" RNAiMAX Reagent (Life Technologies, Invitrogen) following the manufacturerM-bM-^@M-^Ys recommendations. RNA-seq: Polyadenylated RNA was purified from 4 ug of RNA. cDNA libraries were prepared and double-stranded cDNA was fragmented using DNase I according to Illumina specifications, prior to adaptor ligation. Sequencing libraries were amplified and sequenced using an Illumina HiSeq 2000 sequencer. ChIP-seq: 30 million cells at 80% to 90% confluent culture were crosslinked in 1% v/v formaldehyde for 10 min, quenched in 150 mM glycine, washed with cold 1xPBS and harvested by scraping. Cells were lysed in Lysis Buffer (1% w/v SDS, 10 mM EDTA, 50 mM Tris-HCl pH 8.1) with 1x CompleteM-BM-. protease inhibitors (Roche). Cells were sonicated for 10 to 15 min using a BioruptorM-bM-^DM-" UCD-200 (Diagenode) with 30 sec pulses at maximum power. Lysates were diluted to 10 ml in IP Buffer (0.01% w/v SDS, 1.1% v/v Triton-X, 1.2 mM EDTA, 16.7 mM Tris-HCL pH 8.0, 167 mM NaCl) and 10 to 20 ng of antibodies were added and incubated overnight at 4 M-bM-^AM-0C with rotation. Antibodies were immunoprecipitated with 60 M-BM-5l protein G Plus/protein A Agarose Suspension (Calbiochem cat # IP05) and washed sequentially with 1 ml Low Salt Wash Buffer (0.1% w/v SDS, 1% v/v Triton X-100, 2 mM EDTA, 20 mM Tris-HCl pH 8.0, 150 mM NaCl), 1 ml High Salt Wash Buffer (0.1% w/v SDS, 1% v/v Triton X-100, 2 mM EDTA, 20 mM Tris-HCl pH 8.0, 500 mM NaCl), 1 ml LiCl Wash Buffer (0.25 M LiCl, 1% v/v Nonidet P-40, 1% w/v deoxycholate, 1 mM EDTA, 10 mM Tris-HCl pH 8.0) and 1 ml TE buffer (Qiagen). DNA was eluted with 0.4 ml of 0.1 M NaHCO3 and 1% w/v SDS. Eluent was transferred into a new tube and NaCl was added to a final concentration of 200 mM. Crosslinks were reversed by incubation at 65 M-bM-^AM-0C for 2 hours. Next, proteins and RNA were digested by adding 33 M-BM-5l of Digestion Reagent (0.6 M Tris-HCl pH 6.5, 152 mM EDTA, 61 ng/ml RNase A (Invitrogen cat # AM2274) and 0.61 mg/ml Proteinase K (NEB cat # P8102)) following by 1 hour incubation at 37 M-bM-^AM-0C. DNA was extracted by phenol:chloroform and ethanol precipitated. DNA was resuspended in Milli-Q pure water and concentration was measured using QubitM-bM-^DM-" (Invitrogen). At least 10 ng of recovered DNA was used to synthesize sequencing libraries using the ChIP-seq Sample Preparation kit (Illumina). Between 6 and 10 pmoles were used for sequencing on the HiSeq2000 sequencer.
2013-09-28 | E-GEOD-50177 | biostudies-arrayexpress
Project description:The high level of 5-hydroxymethylcytosine (5hmC) present in neuronal genomes suggests that mechanisms interpreting 5hmC in the central nervous system (CNS) may differ from those present in embryonic stem cells. Here we present quantitative, genome-wide analysis of 5hmC, 5- methylcytosine (5mC) and gene expression in differentiated CNS cell types in vivo. We report that 5hmC is enriched in active genes, and that surprisingly strong depletion of 5mC is observed over these regions. The contribution of these epigenetic marks to gene expression depends critically on cell type. We identify methyl-CpG binding protein 2 (MeCP2) as the major 5hmC binding protein in the brain, and demonstrate that MeCP2 binds 5hmC and 5mC containing DNA with similar high affinities. The Rett Syndromecausing mutation R133C preferentially inhibits 5hmC binding. These findings support a model in which 5hmC and MeCP2 constitute a cell specific epigenetic mechanism for regulation of chromatin structure and gene expression. Isolation and sorting was performed as described in (Kriaucionis and Heintz, 2009). Briefly, cerebella were dissected as described above and homogenized in homogenization medium (0.25 M sucrose, 150 mM KCl, 5 mM MgCl2, 20 mM Tricine pH 7.8, 0.15 mM spermine, 0.5 mM spermidine, EDTA-free protease inhibitor cocktail (Roche) using loose (A) and tight (B) glassglass dounce.Homogenate was supplemented with 50% iodixanol (OptiPrep, Axis-Shield, Scotland), 150 mM KCl, 5 mM MgCl2, 20 mM Tricine pH 7.8; and laid on a 29% iodixanol cushion. GC nuclei from WT and Mecp2-null mice were sorted by selecting a specific FSC/SSC population identified from GC EGFP+ mice. We observed that this FSC/SSC gated population in GC EGFP+ animals resulted >92% of the sorted nuclei being EGFP positive. Thus, the gate selected allows us to enrich the sample from 65-70% to 92-96% on GC cells. 5hmC was pulled down as described (Song et al., 2010). After purification DNA was amplified as described in TruSeq DNA Sample kit. 1-0.5 M-NM-<g of DNA was used for each experiment. Sonicated DNA was end-repaired following by ligation to Illumina paired end sequencing adapters (Illumina, PEM-bM-^@M-^P 102M-bM-^@M-^P 1003).), following by amplification with Illumina primers. Input samples were produced for each cell types in both procedures 5hmC enriched were then sequenced using Illumina platform obtaining more than 50 x10-6, 36- bp single-end reads per sample. Reads were aligned to mm9 mouse genome assembly using Bowtie v0.12.7 (-m1 --best). Two biological replicas were done for each of the cell types Single animals per replica were euthanized with CO2 and cerebella were dissected. 4 cerebella was immediately homogenized in ice-cold homogenization buffer (10 mM HEPES [pH 7.4], 150 mM KCl, 5 mM MgCl2, 0.5 mM dithiothreitol (DTT), 100 M-NM-<g/ml cycloheximide, Complete-EDTA-free protease inhibitors (Roche) and RNasin RNase inhibitors (Promega, Madison, WI) using a Teflon-glass homogenizer. Homogenates were centrifuged for 10 minutes at 2,000 M-CM-^W g, 4 M-BM-0C, to pellet cell debris, and incubated with 1% IGEPAL CA-630 (NP-40, Sigma) and 30 mM DHPC (Avanti Polar Lipids, Alabaster, AL) for 5 min. Lysates were centrifuged for 15 minutes at 20,000 M-CM-^W g to pellet insoluble material. At this point, 30 M-NM-<L of supernatant was saved as input sample. Two custom made mouse anti-GFP (clones 19C8 and 19F7; see Heiman et al., 2008) antibodies were captured on Dynal magnetic beads (Invitrogen Corporation, Carlsbad, CA) coupled with protein L (Pierce, Rockford, IL) . The homogenate was incubated with antibody coupled beads at 4M-BM-0C with end-over-end rotation for approximately 16 hours. Beads were subsequently collected on a magnetic rack, washed three times with high-salt wash buffer (10 mM HEPES [pH 7.4], 350 mM KCl, 5 mM MgCl2, 1% NP-40, 0.5mM DTT, 100 M-NM-<g/ml cycloheximide) and RNA was released and purified using Rneasy Micro Kit (Qiagen, Valencia, CA) with in-column DNase digestion. RNA quantity and quality were determined with a Nanodrop 1000 spectrophotometer (Wilmington, DE) and Agilent 2100 Bioanalyzer using RNA 6000 Pico Chip. 4 biological replicas was produced per each cell type. 10 ng of total RNA from cerebellum were converted to cDNA using the NuGEN Ovation RNA-Seq (NuGEN,San Carlos,CA,USA) following manufacturersM-bM-^@M-^Y instructions. The Single Primer Isothermal Amplification (SPIA) method used in this protocol allows the amplification of RNA target in double stranded cDNA under standardized conditions that markedly deplete rRNA without preselecting mRNA. cDNA obtained was quality scored by RNA 6000 PicoChip for Agilent 2100 Bioanalyzer (Agilent, Santa Clara, CA, USA). 1 M-NM-<g of cDNA per sample was sonicated using Covaris-S2 system (Covaris Inc., Woburn, MA, USA), cDNA fragments of 200 bp were end-repaired and adapters were ligated for HiSeq 2000 (Ilumina Inc., San Diego, CA, USA) technology using TruSeq DNA Sample kit (Illumina) and following manufacturer`s instructions. Quality of libraries was assesed using HT DNA High Sensitivity Chip (Agilent) for 2100 Bioanalyzer. Single animals per replica were euthanized with CO2 and cerebella were dissected. 4 cerebella was immediately homogenized in ice-cold homogenization buffer (10 mM HEPES [pH 7.4], 150 mM KCl, 5 mM MgCl2, 0.5 mM dithiothreitol (DTT), 100 M-NM-<g/ml cycloheximide, Complete-EDTA-free protease inhibitors (Roche) and RNasin RNase inhibitors (Promega, Madison, WI) using a Teflon-glass homogenizer. Homogenates were centrifuged for 10 minutes at 2,000 M-CM-^W g, 4 M-BM-0C, to pellet cell debris, and incubated with 1% IGEPAL CA-630 (NP-40, Sigma) and 30 mM DHPC (Avanti Polar Lipids, Alabaster, AL) for 5 min. Lysates were centrifuged for 15 minutes at 20,000 M-CM-^W g to pellet insoluble material. At this point, 30 M-NM-<L of supernatant was saved as input sample. Two custom made mouse anti-GFP (clones 19C8 and 19F7; see Heiman et al., 2008) antibodies were captured on Dynal magnetic beads (Invitrogen Corporation, Carlsbad, CA) coupled with protein L (Pierce, Rockford, IL) . The homogenate was incubated with antibody coupled beads at 4M-BM-0C with end-over-end rotation for approximately 16 hours. Beads were subsequently collected on a magnetic rack, washed three times with high-salt wash buffer (10 mM HEPES [pH 7.4], 350 mM KCl, 5 mM MgCl2, 1% NP-40, 0.5mM DTT, 100 M-NM-<g/ml cycloheximide) and RNA was released and purified using Rneasy Micro Kit (Qiagen, Valencia, CA) with in-column DNase digestion. RNA quantity and quality were determined with a Nanodrop 1000 spectrophotometer (Wilmington, DE) and Agilent 2100 Bioanalyzer using RNA 6000 Pico Chip. 4 biological replicas was produced per each cell type. 10 ng of total RNA per IP or input sample were converted to cDNA using the NuGEN Ovation RNA-Seq (NuGEN,San Carlos,CA,USA) following manufacturersM-bM-^@M-^Y instructions. The Single Primer Isothermal Amplification (SPIA) method used in this protocol allows the amplification of RNA target in double stranded cDNA under standardized conditions that markedly deplete rRNA without preselecting mRNA. cDNA obtained was quality scored by RNA 6000 PicoChip for Agilent 2100 Bioanalyzer (Agilent, Santa Clara, CA, USA). 1 M-NM-<g of cDNA per sample was sonicated using Covaris-S2 system (Covaris Inc., Woburn, MA, USA), cDNA fragments of 200 bp were end-repaired and adapters were ligated for HiSeq 2000 (Ilumina Inc., San Diego, CA, USA) technology using TruSeq DNA Sample kit (Illumina) and following manufacturer`s instructions. Quality of libraries was assesed using HT DNA High Sensitivity Chip (Agilent) for 2100 Bioanalyzer. Single animals per replica were euthanized with CO2 and cerebella were dissected. 4 cerebella was immediately homogenized in ice-cold homogenization buffer (10 mM HEPES [pH 7.4], 150 mM KCl, 5 mM MgCl2, 0.5 mM dithiothreitol (DTT), 100 M-NM-<g/ml cycloheximide, Complete-EDTA-free protease inhibitors (Roche) and RNasin RNase inhibitors (Promega, Madison, WI) using a Teflon-glass homogenizer. Homogenates were centrifuged for 10 minutes at 2,000 M-CM-^W g, 4 M-BM-0C, to pellet cell debris, and incubated with 1% IGEPAL CA-630 (NP-40, Sigma) and 30 mM DHPC (Avanti Polar Lipids, Alabaster, AL) for 5 min. Lysates were centrifuged for 15 minutes at 20,000 M-CM-^W g to pellet insoluble material. At this point, 30 M-NM-<L of supernatant was saved as input sample. Two custom made mouse anti-GFP (clones 19C8 and 19F7; see Heiman et al., 2008) antibodies were captured on Dynal magnetic beads (Invitrogen Corporation, Carlsbad, CA) coupled with protein L (Pierce, Rockford, IL) . The homogenate was incubated with antibody coupled beads at 4M-BM-0C with end-over-end rotation for approximately 16 hours. Beads were subsequently collected on a magnetic rack, washed three times with high-salt wash buffer (10 mM HEPES [pH 7.4], 350 mM KCl, 5 mM MgCl2, 1% NP-40, 0.5mM DTT, 100 M-NM-<g/ml cycloheximide) and RNA was released and purified using Rneasy Micro Kit (Qiagen, Valencia, CA) wit
2013-01-14 | E-GEOD-42880 | biostudies-arrayexpress
Project description:The mammalian RNA-binding protein AUF1 (AU-binding factor 1, also known as heterogeneous nuclear ribonucleoprotein D, hnRNP D) binds to numerous mRNAs and influences their post-transcriptional fate. Given that many AUF1 target mRNAs encode muscle-specific factors, we investigated the function of AUF1 in skeletal muscle differentiation. In mouse C2C12 myocytes, where AUF1 levels rise at the onset of myogenesis and remain elevated throughout myocyte differentiation into myotubes, RIP (RNP immunoprecipitation) analysis indicated that AUF1 binds prominently to Mef2c (myocyte enhancer factor 2c) mRNA, which encodes the key myogenic transcription factor Mef2c. By performing mRNA half-life measurements and polysome distribution analysis, we found that AUF1 associated with the 3M-bM-^@M-^YUTR of Mef2c mRNA and promoted Mef2c translation without affecting Mef2c mRNA stability. In addition, AUF1 promoted Mef2c gene transcription via a lesser-known role of AUF1 in transcriptional regulation. Importantly, lowering AUF1 delayed myogenesis, while ectopically restoring Mef2c expression levels partially rescued the impairment of myogenesis seen after reducing AUF1 levels. We propose that Mef2c is a key effector of the myogenesis program promoted by AUF1. Keywords: ribonucleoprotein complex; post-transcriptional gene regulation; muscle cell differentiation; myocytes; mRNA translation; mRNA stability; post-transcriptional gene regulation; transcriptome C2C12 mouse myoblasts were cultured in Dulbecco's modified Eagle's medium (DMEM; Invitrogen, Carlsbad, CA, USA) supplemented with 10% serum (Invitrogen) and antibiotics (Invitrogen). Differentiation was induced on sub-confluent cultures by replacing the growth media (GM, DMEM with 10% FBS) with differentiation media (DM, DMEM with 2% horse serum). At various time points after differentiation, cells were harvested and RNA was extracted with phenol-chloroform and either saved as input samples for microarrys or subjected to AUF1 or IgG ribonucleoprotein immunoprecipitation. C2C12 cells cultured in GM and DM were lysed in 20 mM Tris-HCl at pH 7.5, 100 mM KCl, 5 mM MgCl2, and 0.5% NP-40 for 10 min on ice and centrifuged at 15,000 M-CM-^W g for 10 min at 4M-BM-0C. The supernatants were incubated with protein-A Dynabeads beads coated with anti-AUF1 (Millipore) or with control IgG (Santa Cruz Biotechnology) antibodies for 2 hr at 4M-BM-0C. The beads were washed with NT2 buffer (50 mM Tris-HCl [pH 7.5], 150 mM NaCl, 1 mM MgCl2, 0.05% NP-40), followed by incubation with 20 units of RNase-free DNase I for 15 min at 37M-BM-0C to remove the DNA. The samples were then incubated for 15 min at 55M-BM-0C with 0.1% SDS/0.5 mg/ml Proteinase K to digest proteins. The RNA from the IP samples was extracted using phenol-chloroform, precipitated, and used along with the RNA from the input samples for cDNA microarrays.
2014-12-22 | E-GEOD-58259 | biostudies-arrayexpress
Project description:This study was designed to explore the role of miRNA-146a (miR-146a) and its target genes in the endothelial cells. In this study we have demonstrated that lipopolysaccharide (LPS) induced upregulation of miR-146a in the human umbilical vein endothelial cells (HUVEC) and the induction was blocked by the silencing of the toll-like receptors (TLRs) adaptor molecules MyD88 and nonspecific NF-M-NM-:B inhibitor BAY 11-7082. In addition, knockdown of miR-146a by transfection of the locked nucleic acid (LNA)-antimiR-146a significantly decreased the increased cell migration and tube formation induced by LPS. A combined analysis of the bioinformatics miRanda algorithms and the whole genome expression microarray of the immunoprecipitated Ago2 ribonucleoprotein complex identified 14 transcripts as the potential target genes. Subsequent transfection with miR-146a precursor pre-miR-146a into the HUVEC validated that the CARD10 was the target gene of the miR-146a both in the transcript and protein level. immunoprecipitation of RNA-induced silencing complexes (RISC) with an Ago2-specific monoclonal antibody followed by RNA extraction and subsequent quantification of mRNAs on microarrays was utilized to identify mRNAs that are associated with the RNA-silencing machinery and are therefore targets of cellular miRNAs. In brief, 100 M-NM-<g of total protein was diluted with 200 M-NM-<L of PBS buffer (pH 7.4). For each sample, 25 M-NM-<L of Protein A/G plus agarose (Santa Cruz, Dallas, TX) was washed with PBS and incubated with 2 M-NM-<g of rabbit anti-Ago2 (Abcam, Cambridge, MA) or rabbit normal IgG (Santa Cruz) antibodies for 2 h at 4M-BM-0C. The beads containing the immobilized anti-Ago2 antibody were then added to 400 M-NM-<L of diluted serum and incubated for 4 h at 4M-BM-0C. The beads were washed 3 times with 1% NT-2 buffer (1% Nonidet P-40, 50 mM Tris-HCl, pH 7.4, 150 mM NaCl, and 2 mM EDTA) and the mixture was split in half. Each sample was eluted in 600 M-NM-<L of lysis/binding buffer for total RNA extraction and subsequent whole genome array experiment. Microarray analyses. Microarray experiments were performed on the total RNA samples from the Ago2 immunoprecipitate (pooling from n=4 in each group) from 1M-CM-^W106 HUVEC with or without 1 M-NM-<g/mL LPS treatment for 24 h in the presence or absence of miR-146a knockdown by LNA-antimiR-146a or LNA-control, respectively. The procedures were carried out following the manufacturerM-bM-^@M-^Ys protocols. Briefly, 0.5 M-NM-<g of total RNA was amplified by a Fluorescent Linear Amplification Kit (Agilent Technologies) and labeled with Cy3-CTP or Cy5-CTP (PerkinElmer, Waltham, MA) during the in vitro transcription process. RNA from the experimental groups and control group was labeled by Cy5 and Cy3, respectively. A total of 0.825 M-NM-<g of Cy-labled cRNA was fragmented to an average size of about 50-100 nucleotides by incubation with fragmentation buffer (Agilent Technologies) at 60oC for 30 minutes. Correspondingly fragmented labeled cRNA is then pooled and hybridized to Agilent Whole Human Genome 4x44k oligo microarray (Agilent Technologies) at 60M-BM-0C for 17 h. After washing and drying by nitrogen gun blowing, microarrays are scanned with an Agilent microarray scanner (Agilent Technologies) at 535 nm for Cy3 and 625 nm for Cy5. Scanned images are analyzed by Feature extraction software 9.5.3 (Agilent Technologies), an image analysis and normalization software is used to quantify signal and background intensity for each feature, substantially normalized the data by rank-consistency-filtering LOWESS method.
2013-09-10 | E-GEOD-50619 | biostudies-arrayexpress
Project description:Transcriptional profiling was performed on cells grown in YEPD medium at 28 M-0C to an OD600 nm = 1.8, in case of cells grown in exponential phase; alternatively, cells were growth in 1% N-acetylglucosamine and 50 mM citrate buffer pH6.0 at 28 M-0C for different times points (15, 60 and 180 minutes) to induce yeast-hypha transition.
2011-08-01 | E-MTAB-517 | biostudies-arrayexpress
Project description:Cells were washed with cold PBS twice and scraped from the plates, then centrifuged at 1000 rpm for 5 min to pellet cells. Washed cells were lysed with 400 L of cell lysis buffer (10 mM Tris-HCl pH7.5, 150 mM NaCl, 0.15% NP-40 and proteinase inhibitor cocktail) and incubated on ice for 10 min. The suspension was carefully add at the top of sucrose buffer (10 mM Tris-HCl pH7.5, 150 mM NaCl, 24% sucrose), and centrifuged at 3200g for 10 min to collect nuclear pellets. Pellets were resuspended in 250 L of Glycerol buffer (20 mM Tris-HCl pH7.5, 75 mM NaCl, 0.5 mM EDTA pH8.0, 50% glycerol), then then immediately add 250 μl Nuclear lysis buffer (10 mM Tris-HCl pH7.5, 300 mM NaCl, 7.5 mM MgCl2, 0.2 mM EDTA pH8.0, 1% NP-40, 1M urea). Mix by vortexing for 4 s and incubate on ice for 2 min. Centrifuge the lysate at 13,000 × g for 2 min to precipitate the chromatin–RNA complex. Briefly rinse the chromatin pellets with PBS-EDTA. RNA was extracted with Trizol reagent. RNA libraries were prepared according to manual of SMARTer smRNA-Seq Kit for Illumina (Clontech, 635031).
2019-10-15 | GSE134103 | GEO
Project description:Glioblastoma stem cells (TS-543) were harvested and cross-linked with 1% formaldehyde for 10 mins at room temperature. The cells were lysed using SDS Lysis buffer for ChIP (1% SDS, 10 mM EDTA, 50 mM Tris-HCl pH 8). The lysate was then sonicated for 25 cycles at 30% amplitude (15 s ON and 45 s OFF). The sonicated samples were then diluted in ChIP dilution buffer (0.01% SDS, 1% Triton-X-100, 1.2 mM EDTA, 16.7 mM Tris–HCl pH 8, 167 mM NaCl) and used for the immunoprecipitation with H3K27ac (Abcam, Ab4729), H2AZ (Active motive, cat#39113) and H3K27ac (Abcam cat#ab8580). After an over-night incubation with antibody, the bound DNA was washed sequentially with low salt wash buffer (0.1% SDS, 1% Triton X 100, 2 mM EDTA, 20 mM Tris–HCl pH 8, 150 mM NaCl), high salt wash buffer (0.1% SDS, 1% Triton X-100, 2 mM EDTA, 20 mM Tris–HCl pH 8, 500 mM NaCl), LiCl wash buffer (0.25 M LiCl, 1% NP40, 1%deoxycholate, 1 mM EDTA, 10 mM Tris–HCl pH 8) and TE wash buffer (10 mM Tris–HCl pH 8, 1 mM EDTA) to remove non-specific sequences and eluted in the elution buffer (84 mg NaHCO3, 1 ml 10% SDS, 9 ml H2O). Then the samples were reverse cross-linked using NaCl at 65°C overnight. The eluted DNA was purified and used for library preparation. Library preparation was performed as previously described as described in Bowman et al. BMC Genomics 2013. Briefly, end repair with NEBNext End Repair enzyme (NEB, E6050) and clean-up with 2.4x volume AMPure XP beads (Beckman Coulter, A63880). A-tailing with Klenow Fragment (NEB, M0212) and purified with 2.4x volume AMPure XP beads. Adapter ligation reactions contained annealed universal adapter and T4 rapid ligase (NEB, B0202) and clean-up with 1.8x volume AMPure XP beads. Chromatin was amplified using KAPA Real-time Library Amplification Kit (KAPABIOSYSTEMS, KK2701) with universal primer and barcoded primer. Amplified chromatin was purified with QIAquick Gel Extraction Kit (Qiagen) and sequenced paired-end with Illumina NextSeq 500.
2021-09-05 | GSE152862 | GEO
Project description:We take the one year old plant for chilling stress (4M-BM-0C, 10h) and controls.Use the Affymetrix poplar gene chip to decrypt the gene functions and mechanisms in Populus simonii leaves. We used microarrays to detail the global programme of gene expression during chilling stress (4M-BM-0C, 10h). Populus simonii leaves were taken from chilling stress (4M-BM-0C, 10h) and controls for RNA extraction and hybridization on Affymetrix microarrays.BH11269-2_Zdqe 13 and BH11269-2_Zdqe 14 from chilling stress (4M-BM-0C, 10h) treatments, CK1 and CK2 controls.
2014-05-16 | E-GEOD-43872 | biostudies-arrayexpress
Project description:GCC was used to determine the structure of E. coli grown in LB or treated with SHX. The bacterial genome is highly condensed into a nucleoid structure. Here we present global analyses of the genome spatial organization for two M-NM-3-proteobacteria: Escherichia coli and Pseudomonas aeruginosa by Genome Conformation Capture. Long distance interactions occurred within the E. coli and P. aeruginosa nucleoids with frequencies that were affected by growth condition and gene dosage. Spatial clustering of genes that are either up or down-regulated depended on the environmental signals, indicating a non-random functional organization of the nucleoid. The largest changes in gene expression upon amino acid starvation occurred in genes that participate in long-range interactions. These genes remained highly spatially clustered when transcript levels decreased. Environment specific interactions were related to DNA motifs but did not correlate with binding sites for nucleoid associated proteins. Overall we identify spatial organization as a significant factor in bacterial gene regulation and suggest that the prokaryotic operon is not simply a linear entity. 4 samples grown in LB; 4 samples treated with SHX. For Genome Conformation Capture (GCC) analyses, E. coli strains were recovered from -80M-BM-0C on LB agar (2%) plates for 24 hours. LB medium (3ml) starter cultures were inoculated and grown (37M-BM-0C, 220rpm, 16h). The Optical Density (OD600) of cultures was measured and used to inoculate LB test cultures to an OD600 of ~0.02. The test cultures were grown (37M-BM-0C, 220rpm) until the OD600 reached ~0.25 and then harvested. For the serine hydroximate (SHX) treated samples the cultures were treated with SHX (500 M-BM-5g/ml, 30 min) before harvesting. E. coli chromatin was prepared according to Rodley et al. (2009)with the following modifications. A total of 5*109 cells were cross-linked with formaldehyde (1% final v/v, 20min, RT) and then quenched with glycine (125mM final, 10min). Cells were collected by centrifugation (4000rpm, 15min, 4M-BM-0C), washed twice (1% PBS, 1% TritonX-100, 5ml/50ml culture) and pelleted (4000rpm, 15min, 4M-BM-0C). Cell pellets were suspended in 800M-NM-<l of B1 lysis buffer (10mM Tris pH 8.0, 50mM NaCl, 10mM EDTA, 20% (w/v) sucrose, 1mg/ml lysozyme) and incubated (37M-BM-0C, 30min). 800M-NM-<l of B2 lysis buffer (200mM Tris pH 8.0, 600mM NaCl, 4% TritonX-100, 1 protease inhibitor tablet (Roche) per 10ml of buffer added just before use) was gently added, mixed by inversion 3-4 times and incubated (37M-BM-0C, 10min). The cell lysate was centrifuged (21,500g, 20min, 4M-BM-0C) and the supernatant decanted. The chromatin was washed once with 1ml of chromatin digestion buffer (10mM Tris-HCl pH 8.0, 5mM MgCl2, 0.1% TritonX-100) by inverting the tube 3-4 times and centrifuged (21,500g, 20min, 4M-BM-0C). The supernatant was decanted and the chromatin pellet was suspended in 500M-NM-<l chromatin digestion buffer. Chromatin samples were aliquoted into 10 sets of 5*108 cells. Samples were digested with HhaI (100U, New England Biolabs). Following digestion a ligation control was added and the samples were ligated with T4 DNA ligase (20U, Invitrogen). Following ligation, cross-links were removed in the presence of proteinase K (0.45U, Fermentas). RNA was removed and pUC19 plasmid (27.4pg/2ml) was added as a sequencing control prior to three extractions with 1:1 Phenol:Chloroform. DNA was column purified (Zymo, DNA clean and concentratorTM-5 kit) according to the manufacturerM-bM-^@M-^Ys instructions and eluted in milliQ H2O before combining for sequencing. 3M-NM-<g of purified DNA was sent for pared-end sequencing at the ATC sequencing facility (Rockville, MD, USA) on an Illumina Hi-Seq. External ligation controls were produced by PCR amplification of short regions from the Lambda phage genome and the pRS426. Primers (Table S4 were designed to include an HhaI site at one end of the final product. PCR products were purified using a PCR purification kit (Qiagen), digested with HhaI (4U, 37M-BM-0C, 2h) and purified again. Purified, digested PCR products were introduced into the GCC samples at a 1:1 ratio with the number of genomes prior to the ligation step during GCC preparation. The pRS426 fragment was introduced into the exponential phase (LB grown) samples and resulted in 220 separate ligation events with HhaI restriction fragments on the genome. The Lambda phage fragment was introduced into the SHX treated samples and resulted in 2 ligation events with HhaI fragments on the genome. Network assembly was performed using the Topography suite v1.19. GCC networks were constructed from 100bp (E. coli) paired end Illumina Genome Analyser sequence reads. Topography uses the SOAP algorithm to position PE tags and single ends which contain a HhaI (E. coli) restriction site onto the E. coli (NC_000913) reference genomes, respectively. Each reference genome also contained the pUC19 (SYNPUC19CV) sequence. For the E. coli alignment the sequences of the pRS426 plasmid and Lambda phage ligation controls were also included in the file to which the sequences were aligned. No mismatches or unassigned bases (N) were allowed during positioning. Except where indicated, bioinformatics and statistical analyses were performed on interactions in which the sequence reads were able to be mapped uniquely onto the reference genome and were above the FDR cut-off value (5). All bioinformatics analysis was perfumed using in house Perl scripts.
2013-05-02 | E-GEOD-40603 | biostudies-arrayexpress