Animal mRNAs are regulated by hundreds of RNA binding proteins (RBPs). The identification of RBP targets is crucial for understanding their function. A recent method, PAR-CLIP, uses photoreactive nucleosides to crosslink RBPs to target RNAs in cells prior to immunoprecipitation. Here, we establish iPAR-CLIP (in vivo PAR-CLIP) to determine, at nucleotide resolution, transcriptome-wide target sites of GLD-1, a conserved, germline-specific translational repressor in C. elegans. We identified 439 reproducible targets and demonstrate an excellent dynamic range of target detection by iPAR-CLIP. Upon GLD-1 knock-down, protein but not mRNA expression of the 439 targets was specifically and highly significantly upregulated, demonstrating functionality. Finally, we discovered strongly conserved GLD-1 binding sites nearby the start codon of target genes. We propose that GLD-1 interacts with the translation machinery nearby the start codon, a so far unknown mode of gene regulation in eukaryotes. Overall design: Arrested L1 worms were grown in liquid culture supplemented with 2mM 4SU or 6SG. 250,000 worms were sufficient for one iPAR-CLIP experiment. Living adult worms were transferred to NGM plates and crosslinked on ice using a Stratalinker (Stratagene) with customized 365nm UV-lamps (energy setting: 2J/cm2). Worms were lysed on ice by douncing in NP40 lysis buffer (50 mM HEPES-K pH 7.5, 150 mM KCl, 2 mM EDTA, 0.5% (v/v) NP-40, 0.5 mM DTT, protease inhibitor cocktail (Roche)). Cleared lysates were treated with RNase T1 (Fermentas) (final concentration 1U/?l) for 15 min at 22ºC. GLD-1::GFP::FLAG fusion proteins were immunoprecipitated for 1h at 4ºC using anti-FLAG antibody (Sigma, F3165) coupled to Protein G magnetic beads (Invitrogen). For one iPAR-CLIP experiment (1ml cleared lysate obtained from 250,000 worms), 300µl beads and 150µg antibody were used. Immunoprecipitates were treated with RNase T1 (100U/?l) for exactly 12 min at 22 ºC. Subsequently, PAR-CLIP was carried out as described previously (Hafner et al, 2010). cDNA libraries were sequenced on a Genome Analyzer II (Illumina).
In vivo and transcriptome-wide identification of RNA binding protein target sites.
Cell line, Subject
View SamplesAnimal mRNAs are regulated by hundreds of RNA binding proteins (RBPs). The identification of RBP targets is crucial for understanding their function. A recent method, PAR-CLIP, uses photoreactive nucleosides to crosslink RBPs to target RNAs in cells prior to immunoprecipitation. Here, we establish iPAR-CLIP (in vivo PAR-CLIP) to determine, at nucleotide resolution, transcriptome-wide target sites of GLD-1, a conserved, germline-specific translational repressor in C. elegans. We identified 439 reproducible targets and demonstrate an excellent dynamic range of target detection by iPAR-CLIP. Upon GLD-1 knock-down, protein but not mRNA expression of the 439 targets was specifically and highly significantly upregulated, demonstrating functionality. Finally, we discovered strongly conserved GLD-1 binding sites nearby the start codon of target genes. We propose that GLD-1 interacts with the translation machinery nearby the start codon, a so far unknown mode of gene regulation in eukaryotes. Overall design: PolyA mRNA was extracted from young adult wildtype (N2) worms and young adult germline less worms (glp-4(bn2) TS) to identify and quantify genes expressed in the young adult germline by sequencing. 2x100 paired end sequencing was performed according to the protocol on the Illumina HiSeq 2000.
In vivo and transcriptome-wide identification of RNA binding protein target sites.
Cell line, Subject
View SamplesWe focused on how mica fine particle influences macrophage activities.
Modulation of macrophage activities in proliferation, lysosome, and phagosome by the nonspecific immunostimulator, mica.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcriptome-wide identification of RNA-binding protein and microRNA target sites by PAR-CLIP.
Cell line
View SamplesTo assess whether the transcripts identified by PAR-CLIP are regulated by the RNA-binding protein (RBP) Quaking (QKI), we analyzed the mRNA levels of mock-transfected and QKI-specific siRNA-transfected cells with microarrays. Transcripts crosslinked to QKI were significantly upregulated upon siRNA transfection, indicating that QKI negatively regulates bound mRNAs (Figure 3H of PMID 20371350), consistent with previous reports of QKI being a repressor.
Transcriptome-wide identification of RNA-binding protein and microRNA target sites by PAR-CLIP.
Cell line
View SamplesTo test the influence of IGF2BPs on the stability of their interacting mRNAs, as reported previously for some targets (Yisraeli, 2005), we simultaneously depleted all three IGF2BP family members using siRNAs and compared the cellular RNA from knockdown and mock-transfected cells on microarrays. The levels of transcripts identified by PAR-CLIP decreased in IGF2BP-depleted cells, indicating that IGF2BP proteins stabilize their target mRNAs. Moreover, transcripts that yielded clusters with the highest T to C mutation frequency were most destabilized (Figure 4G of PMID 20371350), indicating that the ranking criterion that we derived based on the analysis of PUM2 and QKI data generalizes to other RNA-binding proteins (RBPs).
Transcriptome-wide identification of RNA-binding protein and microRNA target sites by PAR-CLIP.
Cell line
View SamplesTo obtain evidence that Argonaute (AGO) crosslink-centered regions (CCRs) indeed contain functional miRNA-binding sites, we blocked 25 of the most abundant miRNAs in HEK 293 cells (Figure 5C of PMID 20371350) by transfection of a cocktail of 2'-O-methyl-modified antisense oligoribonucleotides and monitored the changes in mRNA stability by microarrays (Figure 7A of PMID 20371350). Consistent with previous studies of individual miRNAs (Grimson et al., 2007), the magnitude of the destabilization effects of transcripts containing at least one CCR depended on the length of the seed-complementary region and dropped from 9-mer to 8-mer to 7-mer to 6-mer matches (Figure 7B of PMID 20371350). We did not find evidence for significant destabilization of transcripts that only contained imperfectly paired seed regions.
Transcriptome-wide identification of RNA-binding protein and microRNA target sites by PAR-CLIP.
Cell line
View SamplesTo investigate the role of ADAR1 in gastric carcinogenesis, RNA sequencing and small RNA sequencing were performed in AGS and MKN-45 cells with stable ADAR1 knock-down. Changed frequencies of editing and messenger RNA (mRNA) and microRNA (miRNA) expression were then identified by bioinformatic analyses. Overall design: mRNA and miRNA sequencing were performed before and after stable knockdown of ADAR1 in AGS and MKN-45 cell line
Combinatory RNA-Sequencing Analyses Reveal a Dual Mode of Gene Regulation by ADAR1 in Gastric Cancer.
No sample metadata fields
View SamplesMacrophages have distinct characteristics depending on their microenvironment. We performed proteomic analysis between M1 and M2 macrophages and found that cellular metabolism is the key regulator of macrophage function.
Proteomic Analysis Reveals Distinct Metabolic Differences Between Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) and Macrophage Colony Stimulating Factor (M-CSF) Grown Macrophages Derived from Murine Bone Marrow Cells.
Specimen part
View SamplesSevere fever with thrombocytopenia syndrome phlebovirus (SFTSV), listed in the WHO most dangerous pathogens, has 12-30% fatality rates with a characteristic thrombocytopenia syndrome. With a majority of clinically diagnosed SFTSV patients older than ~50 years, age is a critical risk factor for SFTSV morbidity and mortality. Here, we report an age-dependent ferret model of SFTSV infection and pathogenesis that fully recapitulates the clinical manifestations of human infections. While young adult ferrets (=2 years old) did not show any clinical symptoms and mortality, SFTSV-infected aged ferrets (=4 years old) demonstrated severe thrombocytopenia, reduced white blood cells, and high fever with 93% mortality rate. Moreover, significantly higher viral load was observed in aged ferrets. Transcriptome analysis of SFTSV-infected young ferrets revealed strong interferon-mediated anti-viral signaling, whereas inflammatory immune responses were markedly upregulated and persisted in aged ferrets. Thus, this immunocompetent age-dependent ferret model should be useful for anti-SFTSV therapy and vaccine development. Overall design: Two groups of young adults (20-24 months, =2Y) and aged ferrets (48-50 months), =4 Y) were inoculated via the IM route with 107.6 TCID50 of the SFTSV CB1/2014 strain. PBMCs were isolated at 2 and 4 dpi from each group of ferrets (n=3) by density gradient centrifugation using Ficoll-Paque Plus according to the manufacture's protocol.
Ferret animal model of severe fever with thrombocytopenia syndrome phlebovirus for human lethal infection and pathogenesis.
Specimen part, Subject
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