Project description:We have developed a novel approach named LiRIP-seq to profile the global RNA-RNA interactome in Salmonella enterica. By pulse expressing T4 RNA ligase from an inducible pBAD promoter, LiRIP-seq enables in vivo proximity ligation of Hfq-bound RNAs to their interaction partners. This is followed by enrichment of ligation products (RNA chimeras) using Hfq-coIP and subsequent RNA-seq analysis.
Project description:In this study we used RIL-seq (RNA interaction by ligation and sequencing) to identify Hfq-mediated RNA-RNA interactions in V. cholerae.
Project description:A key challenge for understanding the role(s) played by short, non-coding RNAs (sRNAs) in bacteria is identifying the mRNA targets regulated by the sRNAs. Because the Hfq protein mediates the interactions between many sRNAs and the corresponding target mRNAs, one apporach to identify the mRNA targets of sRNAs is to capture sRNA:mRNA interactions occuring on Hfq by exposing cells to UV-irradiation, which forms cross-links between nucleic acids and proteins. We subjected cells of P. aeruginosa strain PAO1 and a derivative of PAO1 harboring a C-terminal VSV-G epitope on Hfq to UV-irradiation, immune-precipitated the Hfq-RNA complexes, ligated neighboring RNA molecules together with RNA Ligase, and then purififed the resulting RNAs. These RNAs were converted into cDNA libraries and sequenced using the Illumina NextSeq platform and then subjected to RIL-seq analysis pipeline (version 0.78) to identify chimeric RNA molecules. We also performed RNA-seq for PAO1 ∆phrS cells harboring an empty vector (pEV) or a vector expressing PhrS (pPhrS).
Project description:Most E. coli sRNAs interact with their mRNA targets through simultaneous binding to the Hfq chaperon. In this experiment we cross-linked RNA to proteins in-vivo then did Hfq IP followed by ligation of bound RNAs and sequencing to identify sRNA-mRNA interactions. We termed the method RIL-seq for RNA Interactions by Ligation - sequencing.
Project description:RIL-seq experiment of EPEC hfq-flag mutant, in activating- conditions:growth on DMEM at 37°C to mid exponential growth phase (e.g., OD600=0.3). In these conditions EPEC strongly expresses its major virulence components, T3SS and BFP, mimicking infection. Non-activating conditions: overnight growth of static culture on LB medium at 37°C where virulence factors are not expressed. RIL-seq experiments are designed to reveal the interactions of sRNA and their targets.
Project description:In this study we take an integrative approach to capturing targets of the Hfq- associated sRNA PinT, a known post-transcriptional timer of the two major virulence programs of Salmonella enterica, using MS2 affinity purification and RNA- sequencing (MAPS).
Project description:While many general RNA-binding proteins have been described in eukaryotes, the small RNA chaperone Hfq and the translational regulator CsrA remain the only known global RNA-associated cofactors involved in the bacterial post-transcriptional gene expression control. Here, using an RNA-seq-based analysis of the biochemically partitioned ensemble of cellular RNAs, we uncovered a large group of transcripts that interact with the RNA-binding protein ProQ in Salmonella enterica. We show that ProQ is a conserved abundant protein with a wide range of targets, including a new class of ProQ-associated small RNAs, and predicted functions in many cellular pathways. ProQ preferentially associates with highly structured RNAs, filling the so-far vacant niche of a global double-stranded RNA-binding protein and expanding the range of the post-transcriptional regulation in bacteria." This dataset includes representative RIP experiments carried out to characterize the in vivo interactome of the bacterial global RNA-binding protein ProQ. They include a series of RIPs performed on a Salmonella Typhimurium SL1344 ProQ-3xFLAG strain grown to the exponential (OD600=0.5), transition (OD600=2.0) or stationary (6 hours after cells reached OD600=2.0) phases; a RIP perfomed on an Escherichia coli W3110 ProQ-3xFLAG strain grown to the transition phase; a control series of RIPs performed on Salmonella Typhimurium SL1344 ProQ-3xFLAG and PhoP-3xFLAG strains grown to the transition phase. The first series shows how the ProQ RNA interactome evolves over growth in Salmonella, the second reveals ProQ targets in Escherichia, the third illustrates the lack of RNA-binding activity in a negative control, DNA-binding transcription regulator PhoP.