ABSTRACT: Genomic locations of V5-tagged budding yeast Rif1 (including wilt-type and designer mutants) were analysed by ChIP-Seq. Mutants tested were rif1-7A and rif1-7E, in which Ser/Thr residues in the cluster of SQ/TQ sites were mutated to Ala or Glu, respectively. We also tested tested rif1-∆594, in which the C-terminal 594 amino acids were deleted.
Project description:Genomic locations of Myc-tagged budding yeast Rif1 (including wilt-type and designer mutants) were analysed by ChIP-Seq. Mutants tested were rif1-7A and rif1-7E, in which Ser/Thr residues in the cluster of SQ/TQ sites were mutated to Ala or Glu, respectively. The performance of RIF1-9V5 was also tested.
Project description:Wild-type or S2265A version of GFP-RIF1 protein (isoform 1) was over-expressed in Flp-In-T-REx cells (Watts et al. 2020. eLife 9:e58020) and immunopurified using GFP-Trap magnetic agarose beads. Proteins were subjected to on-beads trypsin digestion and resulting peptides were analysed by mass spectrometry for protein identification/quantification and identification of phosphorylated residues. Raw MS file names and descriptions: IP_RIF1_A.raw = GFP-RIF1-L immunoprecipitated from cells without aphidicolin treatment. IP_RIF1_B.raw = GFP-RIF1-L immunoprecipitated from cells treated with 1 µM aphidicolin for 24 hr before harvesting. IP_RIF1_C.raw = GFP-RIF1-L (S2265A) immunoprecipitated from cells treated with 1 µM aphidicolin for 24 hr before harvesting.
Project description: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. 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).
Project description:Despite the overwhelming information about sRNAs, one of the biggest challenges in the sRNA field is characterizing sRNA targetomes. Thus, we develop a novel method to identify RNAs that interact with a specific sRNA, regardless of the type of regulation (positive or negative) or targets (mRNA, tRNA, sRNA). This method is called MAPS: MS2 affinity purification coupled with RNA sequencing. As proof of principle, we identified RNAs bound to RyhB, a well-characterized E. coli sRNA. Identification of RNAs co-purified with MS2-RyhB in a rne131 ?ryhB strain. RyhB (without MS2) was used as control
Project description:Despite the overwhelming information about sRNAs, one of the biggest challenges in the sRNA field is characterizing sRNA targetomes. Thus, we develop a novel method to identify RNAs that interact with a specific sRNA, regardless of the type of regulation (positive or negative) or targets (mRNA, tRNA, sRNA). This method is called MAPS: MS2 affinity purification coupled with RNA sequencing. As proof of principle, we identified RNAs bound to RybB, a well-characterized E. coli sRNA. Identification of RNAs co-purified with MS2-RybB in a rne131 ΔrybB strain. RybB (without MS2) was used as control
Project description:During ribosomal and transfer RNA maturation, external transcribed spacer (ETS) and internal transcribed spacer (ITS) sequences are excised and, as non-functional by-products, are rapidly degraded. The 3’ETS of the glyW-cysT-leuZ polycistronic tRNA precursor was highly and specifically enriched by co-purification with at least two different small regulatory RNAs (sRNAs), RyhB and RybB. Both sRNAs were shown to base pair with the same region in the 3’ETS of leuZ (3’ETSleuZ). Disrupting the pairing by mutating 3’ETSleuZ significantly increased the activity of sRNAs, even under non-inducing conditions. Our results indicate that 3’ETSleuZ prevents sRNA-dependent remodeling of tricarboxylic acid (TCA) cycle fluxes and increases antibiotic sensitivity when sRNAs are transcriptionally repressed. This suggests that 3’ETSleuZ functions as a sponge to absorb transcriptional noise from repressed sRNAs. Finally, the fact that RybB and MicF sRNAs are co-purified with ITSmetZ-metW and ITSmetW-metV strongly suggests a much broader phenomenon. Identification of sRNAs co-purified with MS2-ITSmetZW and MS2-ITSmetWV. ITSmetZW and ITSmetWV (without MS2) were used as control
Project description:Identification of gene expression signatures associated with favourable or unfavourable treatment response and clinical outcome of Hodgkin lymphoma patients.