Modified iCLIP sequencing of HEK293 cells with antibody PTBP1
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Illumina HiSeq 2000
ORGANISM(S): Homo sapiens
SUBMITTER: Jan Attig
PROVIDER: E-MTAB-5027 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The modified iCLIP protocol is based on the previously described protocol (Huppertz et al., 2014) with modifications that enable the definition of readthrough cDNAs. HeLa cells were crosslinked with 0.15mJ/cm2 254nm UV light. Protein G Dynabeads were used for immunoprecipitations (IP). For each IP, 100 l of beads were washed in iCLIP lysis buffer (50mM Tris-HCL pH 7.4, 100mM NaCl, 1% NP-40, 0.1% SDS, 0.5% sodium deoxycholate), and incubated with the anti-eIF4A3 antibody or polyclonal mAb BB7 serum anti-PTBP1. To prepare the cell lysate, the cells were lysed with 1 mL iCLIP lysis buffer (final concentration 2mg/mL), sonicated (Bioruptor, 5x5 sec on/off), incubated with RNase I (1-2 x10-3 U/mL for eIF4A3) at 37C for 3 min, and centrifuged. After the pellet had dissolved, the mixture was diluted with H2O to 1000 L and an additional centrifugation was performed. The supernatant of the iCLIP lysis buffer (1 mL) and the MSB lysis buffer (1 ml) were combined and added to the antibody-coupled beads, which were then rotated at 4C for 2 h (final urea concentration 175 mM). The beads were then washed with high-salt washing buffer (50mM Tris-HCL pH 7.4, 1M NaCl, 1% NP-40, 0.1% SDS, 0.5% sodium deoxycholate). After the first round of washes, the library was split into 10%, which were radioactively labelled (according to the basic iCLIP protocol), and 90%, which proceed through 3 adapter addition, an additional phosphorylation (0.2 l PNK, 0.4 l cold ATP (1mM), 0.4 l 10x PNK buffer, 3 l water) and a 5 marker ligation (6 l water, 5 l 4X ligation buffer, 2 l RNA ligase, 1 l RNasin, 2 l 5 marker (100 M), 4 l PEG400). The sequence of the 5 marker is CAGUCCGACGAUC, which corresponds to the Illumina short RNA 5 Adapter (RA5), part #15013205; this sequence is not complementary to the primers used for amplification of iCLIP cDNA libraries (Huppertz et al., 2014). We then produced sequence reads of 120 nt using the Illumina HiSeq platform for eIF4A3 iCLIP. The rest of the protocol was carried out as previously described (Huppertz et al., 2014). Huppertz, I., Attig, J., D'Ambrogio, A., Easton, L.E., Sibley, C.R., Sugimoto, Y., Tajnik, M., Konig, J., and Ule, J. (2014). iCLIP: protein-RNA interactions at nucleotide resolution. Methods 65, 274-287.
2016-11-24 | E-MTAB-4000 | 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: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).
2019-07-02 | GSE133625 | 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:The CLIP procedures were conducted using HeLa cells according to the previous study (Liu et al., 2016) with slight modifications. Briefly, 4 plates of HeLa cells in 15 cm dishes were transfected with pPB/ALKBH3 plasmid for 48 h to reach about 90% cell confluency. After washing twice with ice-cold PBS, cells were irradiated twice with 400 mJ/cm2 at 254 nm by Stratalinker on ice. Cells were lysed in high salt lysis buffer (300 mM NaCl, 0.2% NP-40, 20 mM Tris-HCl PH 7.6, 0.5 mM DTT, protease inhibitor cocktail (1 tablet/50 ml), and RNase inhibitor (1:200)) at 4°C for 30 min. Supernatant was collected after centrifuged at 17,000 g at 4°C for 15 min and further treated with 1 U RNase T1 for 15 min at 24 °C. After centrifugation and filtration through 0.22 µM filter, 10% supernatant was collected as input for further sequencing analysis. Anti-Flag M2 beads (Sigma-Aldrich, St. Louis, MO, 80 μl) were washed three times with lysis buffer and incubated with the filtered supernatant at 4°C for 4 hrs. After removing the flow through by magnetic rack, beads and input were further incubated with 10 U RNase T1 exactly for 8 min. Samples were treated with 95 µL commercial PNK buffer and 0.5 U PNK for 15 min at 37 °C. After treatments, final concentration of 100 µM ATP and 1 U PNK were added and incubated at 37 °C for another 30 min. The RNA/protein complexes were eluted by NuPAGE 1 × loading buffer and fractionated by neutral NuPAGE 4–12% bis-tris gel. After cutting the gel, RNAs were recovered by proteinase K digestion in proteinase K buffer, followed by phenol/chloroform extraction using glycogen as carrier. The RNA fragments were ligated to adapter and established library by NEB small RNA library preparation kit (E7330S).
2022-03-01 | GSE112625 | GEO
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:A549 cells were transfected with 100 pmol DNA probes complementary to the back-splice site of circITGB6 or PDPN 3’UTR region. 24 h later, cells were washed with PBS and lysed with the lysis buffer (150 mM NaCl, 20 mM Tris-HCl, pH 7.5, 1.5 mM MgCl2, 0.5% NP-40, 0.5% Triton X-100, 10% glycerol, RNase inhibitors (Thermo Scientific), protease and phosphatase inhibitor cocktails). Pre-treated streptavidin magnetic beads were incubated with cell lysates at 4°C for 1 h, followed by washing five times with the washing buffer (20 mM Tri-HCl, pH7.5, 1 mM EDTA and 450 mM NaCl) and elution with Laemmli sample buffer. The circITGB6- or PDPN mRNA- interacting proteins were subjected to SDS-PAGE and visualized by coomassie blue staining or immunoblot analysis. Protein bands were excised and identified by LC-MS/MS mass spectrometry and Proteome Discoverer software (version 1.4; Thermo Scientific).
2023-10-13 | PXD043341 | Pride
Project description:0.3g of flowers were ground in liquid nitrogen. The powder was extracted for 30 min [H2] in 1.5 ml of lysis buffer (50mM Tris HCl pH 8.0, 50mM NaCl, 1% Triton x-100 and 1 x cOmplete™ EDTA-free protease inhibitor (Roche)). After removal of cell debris by centrifugation (2 times 10 min, 16000 x g, 4 °C) the cleared supernatants were incubated for 30 min with GFP or FLAG antibodies coupled to magnetic microbeads (μMACS GFP and DYKDDDDK isolation Kits, Miltenyi). Beads were loaded on magnetized MACS separation columns equilibrated with lysis buffer and washed 4 times with 300 µl washing buffer (50mM Tris HCL pH 7.5, 25 or 50 mM NaCl, 0,1 % Triton). Samples were eluted in 50 µl of pre-warmed elution buffer (Milteny). Control IPS were performed in Col-O using either GFP or FLAG antibodies.
2020-04-15 | PXD014447 | Pride
Project description:Chromatin immunoprecipitation was performed with modification of the protocols described before (Lee et al., 2006; Lilja et al., 2007). Briefly, the chorion was removed from 12-hour old embryos, cross-linked using 2% paraformaldehyde and resuspended in storage buffer (50mM Tris-HCl pH8.0, 1 mM EDTA). Embryos were then lysed in SDS-lysis buffer (1.0 ml 5 M NaCl, 2.5 ml 1 M Tris-HCl pH 8.0, 0.5 ml 0.5M EDTA, 2.5 ml 10 % SDS), resuspended in SDS-lysis and Triton buffer (1.0 ml 5 M NaCl, 5.0 ml 1 M Tris-HCl pH 8.0, 0.5 ml 0.5M EDTA, 2.5 ml Triton X-100, protease inhibitor cocktail) and sonicated on ice to an average length of 350 bp. The resulting sheared chromatin (25Izg) was subjected to immunoprecipitation using anti-Myc antibody (Santa Cruz) as described previously (Lee et al., 2006). ChIP-sequencing libraries were constructed following manufactureras instructions (Illumina). The resulting DNA libraries were sequenced using Illumina platform (University of Massachusetts Medical School Core Facility).
2019-02-02 | E-MTAB-4083 | biostudies-arrayexpress
Project description:We determined genome-wide nucleosome occupancy in mouse embryonic stem cells and their neural progenitor and embryonic fibroblast counterparts to assess features associated with nucleosome positioning during lineage commitment. Cell type and protein specific binding preferences of transcription factors to sites with either low (e.g. Myc, Klf4, Zfx) or high (e.g. Nanog, Oct4 and Sox2) nucleosome occupancy as well as complex patterns for CTCF were identified. Nucleosome depleted regions around transcription start and termination sites were broad and more pronounced for active genes, with distinct patterns for promoters classified according to their CpG-content or histone methylation marks. Throughout the genome nucleosome occupancy was dependent on the presence of certain histone methylation or acetylation modifications. In addition, the average nucleosome-repeat length increased during differentiation by 5-7 base pairs, with local variations for specific genomic regions. Our results reveal regulatory mechanisms of cell differentiation acting through nucleosome repositioning. For chromatin immunoprecipitation, for each sample, 1 x 106 cells were cross-linked with 1% PFA and cell nuclei were prepared using a swelling buffer (25 mM Hepes pH 7.8, 1 mM MgCl2, 10 mM KCl, 0.1% NP-40, 1 mM DTT). Chromatin was sheared to mononucleosomal fragments. After IgG preclearance the sheared chromatin was incubated with 4 µg of either a H3K9ac (Abcam, ab4441), a H3K27ac (Abcam, ab4729), or a H3K9me3 (Abcam ab8898) antibody over night. After washes with sonication (10 mM Tris-HCl, pH 8.0, 200 mM NaCl, 1 mM EDTA, 0.5% N-lauroylsarcosine, 0.1% Na-deoxycholate), high-salt- (50 mM Hepes pH 7.9, 500 mM NaCl, 1mM EDTA, 1% Triton X-100, 0.1% Na-deoxycholate, 0.1% SDS), lithium- (20 mM Tris-HCl pH 8.0, 1mM EDTA, 250 mM LiCl, 0.5% NP-40, 0.5% Na-deoxycholate) and 10 mM Tris-HCl, chromatin was eluted from the protein G magnetic beads and the crosslink was reversed over night. After RNase A and proteinase K digestion, the DNA was purified and subsequently cloned into a multiplexed Illumina library according to standard protocols. Sequenced 50 bp reads were mapped with bowtie and subsequently clustered with MACS 55 implemented in the Genomatix software suite (Genomatix, Munich, Germany) using a p-value of 10-5.
2012-10-21 | E-GEOD-40951 | biostudies-arrayexpress