SsDRIP-seq analysis of R-loop level in shCTRL, shMETTL3 and shDDX21 HeLa cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE134101 | GEO | 2019/10/15
REPOSITORIES: GEO
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2019-10-15 | GSE134103 | GEO
Project description:J1 mouse embryonic stem cells (mESCs) and NIH-3T3 fibroblasts were grown in standard media conditions. Hybridized cells were fixed with 4% paraformaldehyde; permeabilized in 70% ethanol; incubated for 12 hours at 30C in an RNA preserving hybridization (RPH) buffer (300 mM Sodium chloride, 30mM Sodium citrate, 2.1M Ammonium sulfate, 25% formamide, 10 mM EDTA, 1 mg/ml E. Coli tRNA, 500 μg/ml BSA); and reverse cross-linked for 1 hour at 50C with Sodium dodecyl sulfate (SDS) and Proteinase K (100 mM NaCl, 10 mM Tris pH 8.0, 1 mM EDTA, 0.5% SDS, 500 μg/ml Proteinase K).
2014-03-20 | GSE55919 | GEO
Project description:Flag-YBX1 overexpressed T24 cells pellets were resuspended with 2 volume of lysis buffer (150 mM KCl, 10 mM HEPES pH 7.6, 2 mM EDTA, 0.5% NP-40, 0.5 mM DTT, 1:100 protease inhibitor cocktail, 400 U/ml RNase inhibitor), and incubated at 4 °C for 30 min with rotation. Then the lysate was centrifuged at 15 000 g for 20 min. Before incubating the lysate with Flag beads, 100ul were taken as input. The anti-Flag M2 magnetic beads (Sigma, 10 μl per mg lysate) were washed with NT2 buffer (200 mM NaCl, 50 mM HEPES pH 7.6, 2 mM EDTA, 0.05% NP-40, 0.5 mM DTT, 200 U/ml RNase inhibitor) four times. Cell lysate was mixed with M2 beads and incubated at 4 °C for 4 h with rotation. The beads were washed two times with 1 ml ice-cold NT2 buffer. Then the beads were subject to Micrococal nuclease (NEB) digestion (1:1 000 000 dilution) for 8 min at 37 °C. The beads were cooled on ice immediately for 5 min and washed two times with 1 ml ice-cold 1× PNK+EGTA buffer (50 mM Tris-HCl pH 7.5, 20 mM EDTA, 0.05% NP-40, 200 U/ml RNase inhibitor) and two times with 1 ml ice-cold 1× PK buffer (50 mM NaCl, 100 mM Tris-HCl pH 7.5, 10 mM EDTA, 0.2% SDS, 200 U/ml RNase inhibitor). Then the beads were digested with 200 μl pre-heated (20 min at 50 °C) Proteinase K and RNAs were extracted with an equal volume of Acid-Phenol: Chloroform, pH 4.5 (Ambion). The RNAs were subjected to rRNA removal and Bisseq. The libraries were sequenced on the Illumina HiSeq X-Ten platform at Novogene (Tianjin, CA) with paired-end 150 bp read length.The m5C sites were called using meRanCall from meRanTK (FDR < 0.01).
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2014-03-20 | GSE55672 | GEO
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2014-03-20 | E-GEOD-55919 | biostudies-arrayexpress
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: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:Parasite lysates were centrifuged (20,000 g, 4°C, 15 min). Beads (blank and with linker attached) were washed 3× with water then twice with lysis buffer. The lysate (~2 mg total protein) was first incubated with 2 mg blank beads for 30 min at 4°C with rotating agitation. The lysate was divided into two then incubated with either 1% DMSO or 100 µM DDD01510706 (competitor) for 30 min at 4°C with agitation. Finally, lysates were incubated with 2 mg of compound-bound beads for 1 h at 4°C with agitation. The beads were then washed 3× with wash buffer (0.8% (w/v) octyl β-D-glucopyranoside, 50 mM Tris pH 8.0, 5 mM EDTA, 1 mg/mL BSA) and 2× Tris-buffered saline (TBS; 50 mM Tris-Cl pH 7.5, 150 mM NaCl). Samples were run 1.5 cm into a Bis-Tris 10% (w/v) acrylamide gel and stained with Coomassie quick reagent for 30 min. The entire gel bands were removed and subjected to in-gel reduction with 10 mM dithiothreitol, alkylation with 50 mM iodoacetamide and digestion with 12.5 μg/mL trypsin (Pierce) for >16 h at 37°C. Recovered tryptic peptides were then vacuum dried prior to analysis
2022-10-15 | PXD033740 | Pride
Project description:Ten 15 cm2 plates of HEK293 cells stably expressing TAP-vector, TAP-CSAG1, or TAP-CSAG2 were lysed with TAP lysis buffer (10% (v/v) glycerol, 50 mM HEPES-KOH pH 7.5, 100 mM KCl, 2 mM EDTA, 0.1% (v/v) NP-40, 10 mM NaF, 0.25 mM Na3VO4, 50 mM β-glyerolphosphate, 2 mM DTT, and 1X protease inhibitor cocktail (Sigma)) and cleared supernatants were bound to IgG-Sepharose beads (GE Amersham) and then washed in lysis buffer and TEV buffer (10 mM HEPES-KOH pH 8.0, 150 mM NaCl, 0.1% (v/v) NP-40, 0.5 mM EDTA, 1 mM DTT, and 1X protease inhibitor cocktail). Protein complexes were cleaved off the beads by TEV protease (Sigma) and incubated with calmodulin-Sepharose beads (GE Amersham) in calmodulin binding buffer (10 mM HEPES-KOH pH 8.0, 150 mM NaCl, 1 mM Mg acetate, 1 mM imidazole, 0.1% (v/v) NP-40, 6 mM CaCl2, 10 mM 2-mercaptoethanol) and then washed in calmodulin rinse buffer (50 mM Ammonium bicarbonate pH 8.0, 75 mM NaCl, 1 mM Mg Acetate, 1 mM Imidazole, 2 mM CaCl2) before eluted with SDS sample buffer, subjected to SDS-PAGE, and stained with GelCode Blue stain (Thermo Fisher Scientific) before protein identification by LC-MS/MS.
2020-09-01 | PXD020231 | Pride
Project description:Purpose: this study is to analyze the chromatin landscape of H3R2mes in Plasmodium falciparum. Methods: In this study, H3R2me2s enrichment in the chromatin of wildtype parasite at schizont stage was analyzed by Cleavage Under Targets and Tagmentation (CUT&Tag) coupled with next generation sequencing (CUT&Tag-seq). Synchronized WT 3D7 at 40–46 hpi schizonts were harvested and fixed with 1% formaldehyde for 1 min at room temperature, followed by lysis with 0.06% saponin. The parasite pellets were suspended in 100 μl nuclear extraction buffer (20 mM HEPES–KOH pH 7.9, 10 mM KCl, 0.1% Triton X-100, 20% Glycerol, 0.5 mM Spermidine, 1x EDTA-free Protease Inhibitor cocktail). Ten μl of activated Concanavalin A-coated magnetic beads (EpiCypher # 21-1401) were added to each sample (~0.5 × 106 nuclei) and incubated for 10 min. The bead-bound nuclei were resuspended in 50 μl Antibody150 buffer (20 mM HEPES, pH 7.5, 150 mM NaCl, 0.5 mM spermidine, 1× protease inhibitor cocktail, 0.01% digitonin, 2 mM EDTA) containing 0.5 μg of rabbit anti-H3R2me2s (Epigentek #A-3705-050) as the primary antibody or rabbit IgG (Cell Signaling Technology #2729S) serving as a control. The primary antibody was then removed, and nuclei were then incubated with 0.5 μg of the secondary antibodies in 50 μl of Digitonin150 buffer (Antibody150, no EDTA) at room temperature for 30 min. The secondary antibodies were mouse anti-rabbit IgG (Invitrogen #31213). The nuclei were washed thrice with 200 μl Digitonin150 Buffer for 5 min to remove unbound antibodies and finally resuspended in 50 μl Digitonin300 Buffer (Digitonin150 but with 300 mM NaCl). Then, 2.5 μl of CUTANA pAG-Tn5 (EpiCypher #15-1017) were added to each reaction at room temperature for 1 h. The nuclei were washed thrice for 5 min in 200 μl Digitonin300 Buffer to remove the unbound pA-Tn5. Next, the nuclei were resuspended in 50 μl Tagmentation buffer (10 mM MgCl2 in Digitonin300) and incubated at 37 °C for 1 h. The beads were washed with 50 µl TAPS buffer (10 mM TAPS, pH 8.5, 0.2 mM EDTA), mixed with 5 µL SDS release buffer (10 mM TAPS pH 8.5; 0.1% SDS) to quench tagmentation, and then incubated for 1 hr at 58ºC to release tagmented chromatin into solution. Finally, 15 µl of 0.67% Triton-X was added to each reaction to quench SDS. PCR with appropriate barcoded primers was performed using the CUTANA High Fidelity 2x PCR Master Mix (EpiCypher #15-1018) according to the manufacturer's recommendations. Amplified DNA libraries were captured by incubating with 1.3 × Kapa pure beads (Roche #KK8001) according to the manufacturer's recommendations, and next-generation sequencing was performed on the NextSeq 550 platform. The reads of CUT&Tag-seq from three biological replicates were mapped to the P. falciparum genome (PlasmoDB Release 39.0) by using BWA (Li and Durbin 2009) after FastQC quality control. The peak calling was finished by MACS2 version 2.2.7.1 with parameters ‘callpeak -f BAMPE’ and a q-value cutoff of 0.05. Results: The three replicates of CUT&Tag-seq using nuclei from the schizont stage showed high reproducibility, with correlation coefficients of ~0.8. Peak calling using criteria of presence in at least two of three replicates with at least 50% overlap of the peaks identified 1629 H3R2me2s signals, distributed among the 14 chromosomes. Among these peaks, 57% (927) are localized at 5’ UTR regions of 791 genes, 35% (577) at coding regions of 470 genes, and 8% (125) at 3’ UTR regions of 115 genes. The peaks are ~17.44 bp wide and ~1265 bp from the ATG sites. Comparing the transcriptome data showed genes with H3R2me2s enrichment in the 5’ UTRs showed significantly higher expression than other genes in the genome, suggesting that H3R2me2s is associated with gene activation. In addition, H3R2me2s peaks were highly co-localized with the active mark H3K9Ac, H2A.Z, and H3K4me3, further implying H3R2me2s as a euchromatin mark. Gene ontology (GO) enrichment analysis revealed a multitude of cellular pathways, including merozoite invasion, transcription, translation, stress response, cell cycle, schizogony, cell adhesion, exit from RBC, vesicle transport, signal transduction, DNA repair, and telomere organization, which are potentially regulated by this euchromatic mark. Conclusions: Collectively, H3R2me2s is a active chromatin mark and regulates invasion and other important processes in human malaria parasite.
2023-06-28 | GSE214535 | GEO