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.
Project description:The molecular roles of many RNA‐binding proteins in bacterial post‐transcriptional gene regulation are not well understood. Approaches combining in vivo UV crosslinking with RNA deep sequencing (CLIP‐seq) have begun to revolutionize the transcriptome‐wide mapping of eukaryotic RNA‐binding protein target sites. We have applied CLIP‐seq to chart the target landscape of two major bacterial post‐transcriptional regulators, Hfq and CsrA, in the model pathogen Salmonella Typhimurium. By detecting binding sites at single‐nucleotide resolution, we identify RNA preferences and structural constraints of Hfq and CsrA during their interactions with hundreds of cellular transcripts. This reveals 3′‐located Rho‐independent terminators as a universal motif involved in Hfq–RNA interactions. Additionally, Hfq preferentially binds 5′ to sRNA‐target sites in mRNAs, and 3′ to seed sequences in sRNAs, reflecting a simple logic in how Hfq facilitates sRNA–mRNA interactions. Importantly, global knowledge of Hfq sites significantly improves sRNA‐target predictions. CsrA binds AUGGA sequences in apical loops and targets many Salmonella virulence mRNAs. Overall, our generic CLIP‐seq approach will bring new insights into post‐transcriptional gene regulation by RNA‐binding proteins in diverse bacterial species.
Project description:The vast number of noncoding RNAs in bacteria suggests that major post-transcriptional circuits beyond those controlled by the global RNA-binding proteins Hfq and CsrA may exist. To identify additional globally acting RNPs we have developed a method (gradient profiling by sequencing; Grad-seq) to partition the full ensemble of cellular RNAs based on their biochemical behavior. Consequently, we discovered transcripts that commonly interact with the osmoregulatory protein ProQ in Salmonella enterica. We show that ProQ is a conserved abundant RNA-binding protein with a wide range of targets, including a new class of ProQ-associated small RNAs that are highly structured and function to regulate mRNAs in trans. Based on its ability to chart the functional landscape of all cellular transcripts irrespective of their length and sequence diversity, Grad-seq promises to aid the discovery of major functional RNA classes and RNA-binding proteins in many organisms.
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 is a representative experiment carried out to characterize sedimentation properties of bacterial transcripts genome-wide. Downstream analysis of their sedimentation profiles enables their biochemical classification and is a prerequisite for identification of global RNA-binding proteins.
Project description:In many bacteria, the base pairing between most small regulatory RNAs (sRNAs) and their targets is facilitated by the Hfq RNA chaperone. However, recent studies have shown FinO-domain proteins also bind sRNAs. To compare the contributions of Hfq and the FinO-domain ProQ protein in Escherichia coli, we carried out RIL-seq, which allows global identification of two RNAs bound to the same protein. We detected hundreds of RNA pairs on ProQ. Intriguingly, 33% of the ProQ-bound RNA pairs are also found associated with Hfq, suggesting overlapping, complementary or competing roles for the two proteins.
Project description:This study investigates the CsrA regulon of the food-borne pathogen Campylobacter jejuni. Direct RNA binding targets of CsrA in two strains of C. jejuni, NCTC11168 and 81-176, were determined using RIP-seq. Identification of CsrA binding sites in two C. jejuni strains using RIP-seq
Project description:Three groups of sex- and aged-matched 9-12 week old C57BL/6 wild type mice and gp91-/-phox mice were infected by i.v. injection of bacterial suspensions: Group 1 represents wild type C57BL/6 mice infected with virulent S. Typhimurium SL1344 grown in vitro. (Raw files: OTNCS_AGSL1344#3C#9C#10C-XX) Group 2 represents wild type C57BL/6 mice infected with virulent S. Typhimurium SL1344 grown in vivo for 72 h in the Group 1 C57BL/6 mice. (Raw files: OTNCS_AGSL1344#9F#10F-XX) Group 3 represents immunodeficient gp91-/-phox mice infected with virulent S. Typhimurium SL1344 grown in vitro. (Raw files: OTNCS_AGSL1344#11C#12C#13C-XX) And Input (Raw files: OTNCS_AGSL1344mixedAa-XX and OTNCS_AGSL1344mixedAb-XX)
Project description:Recently, we developed an in vivo technology to draw the interacting map of a specific small regulatory RNA (sRNA). We called it MAPS for MS2-affinity purification coupled with RNA sequencing. In this study, we performed MAPS with SraL sRNA (Salmonella Typhimurium SL1344).
Project description:IP (as previously described Chao et al., 2012; Smirnov et al., 2016) of ProQ-3xFLAG and FinO-3xFLAG in Salmonella SL1344 at different growth conditions.
Project description:FinO-domain proteins such as ProQ of the model pathogen Salmonella enterica have emerged as a new class of major RNA-binding proteins in bacteria. ProQ has been shown to target hundreds of transcripts including mRNAs from many virulence regions but its role, if any, in bacterial pathogenesis has not been studied. Here, using a Dual RNA-seq approach to profile ProQ-dependent gene expression changes as Salmonella infects human cells, we reveal dysregulation of bacterial motility, chemotaxis and virulence genes which is accompanied by altered mitogen-activated protein kinase signaling in the host. Comparison with Hfq, Salmonella’s other major RNA chaperone, reinforces the notion that these two global RNA binding proteins work in parallel to ensure full virulence. Of newly discovered infection-associated ProQ-bound small noncoding RNAs, we show that STnc540 represses a virulence-related magnesium transporter mRNA in a ProQ-dependent manner. Together, this comprehensive study uncovers the relevance of ProQ for Salmonella infection and highlights the importance of RNA-binding proteins in regulating bacterial virulence programs.