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.
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.
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.
Project description:The aim of the project is to identify transcriptome-wide binding sites for the global RNA-binding protein ProQ in Salmonella during intracellular-like conditions.
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:ProQ has become a paradigm for the emerging family of FinO domain-containing RNA binding proteins. ProQ in Salmonella enterica has been shown to act as a global RNA binding protein as it interacts with a plethora of sRNAs and mRNAs. However, little was known about processes ProQ regulates in Salmonella which have precluded to functionally characterize ProQ in vivo. In here, we show that ProQ represses the utilization of succinate as carbon source. The latter allowed applying deep mutational scanning to ProQ to identify residues within the protein important to its function in vivo. ProQ carries a FinO domain, responsible for RNA binding, as its N-terminal domain fused via a linker to a C-terminal domain with unknown function. Remarkably, residues within both the N-terminal domain and C-terminal domain of the protein are found to be essential for ProQ function. Mutations in the C-terminal lead to non-fuctional variants to regulate succinate utilization but capable to interact with RNA. On the contrary, mutations on the N-terminal domain leave ProQ functionally inactive to regulate ProQ function in vivo and to interact with RNA. Notably, the inability to interact with RNA render ProQ unstable. The latter leads to an active Lon protease mediated degradation suggesting that interaction with RNA represents a control mechanism to modulate ProQ turnover.