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: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:Determination of the RNA interactome of the RNA-binding protein Hfq at three different time-point during growth on the three strains PAO1, PA14 and IHMA87, representing the three major P. aeruginosa phylogenetic lineages, using RIP-seq.
Project description:Hfq is an RNA chaperone and an important post-transcriptional regulator in bacteria. Using chromatin immunoprecipitation together with DNA sequencing (ChIP-Seq), we show that Hfq associates with hundreds of different regions of the Pseudomonas aeruginosa chromosome. These associations are abolished when transcription is inhibited, indicating they reflect Hfq binding to transcripts during their synthesis. Analogous ChIP-Seq analyses with the post-transcriptional regulator Crc reveal that it associates with many of the same nascent transcripts as Hfq, an activity we show is Hfq dependent. Our findings indicate that Hfq binds many transcripts co-transcriptionally in P. aeruginosa, often in concert with Crc, and uncover direct regulatory targets of these proteins. They also highlight a general approach for studying the interactions of RNA-binding proteins with nascent transcripts in bacteria. The binding of post-transcriptional regulators to nascent mRNAs may represent a prevalent means of controlling translation in bacteria where transcription and translation are coupled.
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:This study represents the first attempt to characterize the RNA chaperone Hfq regulon in bacterial pathogen using an integrative omics approach. Gene expression profiles were analyzed by RNA-seq and protein amounts in cell-associated and cell-free fractions were determined by LC-MS/MS technique. Comparative analysis of transcriptomic and proteomic data revealed solid correlation considering the role of Hfq in post-transcriptional control of gene expression. Importantly, our study confirms and further enlightens the role of Hfq in pathogenicity of B. pertussis.