Project description:Whole transcriptome assessment of the Yersinia pseudotuberculosis strain YPIII. The Y. pseudotuberculosis crp regulon was determined in Yersinia minimal minimum developed for the study. Crp is a key regulator coordinating virulence and metabolism.
Project description:Colonization of the intestinal tract and dissemination into deeper tissues by the enteric pathoÂgen Yersinia pseudotuberculosis demands expression of a special set of virulence factors important for the initiation and the persistence of the infection. In this study we demonstrate that many virulence-associated functions are coregulated with the carbohydrate metabolism. This link is mediated by the carbon storage regulator (Csr) system, including the regulatory RNAs CsrB and CsrC, and the cAMP receptor protein (Crp), which both control virulence gene expression in response to the nutrient composition of the medium. Here, we show that Crp regulates the synthesis of both Csr RNAs in an opposite manner. A loss of the crp gene resulted in a strong upregulation of CsrB synthesis, whereas CsrC levels were strongly reduced leading to downregulation of the viruÂlence regulator RovA. Switching of the Csr RNA involves Crp-mediated reÂpression of the response regulator UvrY which activates csrB transcription. To elucidate the regulatory links between virulence and carbon metabolism, we performed comparative metabolome, transÂÂÂcripÂtome and phenotypic microarray analyses and found that Crp promotes oxidative catabolism of many different carbon sources, whereas fermentative patterns of metabolism are favoured when crp is deleted. Mouse infection experiments further demonstrated that Crp is pivotal for a successÂful Y. pseudoÂtuberÂculosis infection. In summary, placement of the Csr system and important virulence factors under control of Crp enables this pathogen to link its nutritional status to virulence in order to optimize bioÂlogical fitness and infection efficiency through the infecÂtious life cycle. Y. pseudotuberculosis YPIII or the isogenic crp mutant strain were grown to late stationary phase at 25°C. Four biological replicates were employed for each experiment consisting of two pooled individual cultures and two pooled RNA preparation samples, respectively. Total RNA was extracted using SV Total RNA Isolation System (Promega). The samples were treated with RNase-free DNase (Roche Applied Science) and the quality of the RNA was confirmed by the lack of PCR amplification of the hns gene and by using an Agilent 2100 Bioanalyzer.
Project description:Colonization of the intestinal tract and dissemination into deeper tissues by the enteric pathogen Yersinia pseudotuberculosis demands expression of a special set of virulence factors important for the initiation and the persistence of the infection. In this study we demonstrate that many virulence-associated functions are coregulated with the carbohydrate metabolism. This link is mediated by the carbon storage regulator (Csr) system, including the regulatory RNAs CsrB and CsrC, and the cAMP receptor protein (Crp), which both control virulence gene expression in response to the nutrient composition of the medium. Here, we show that Crp regulates the synthesis of both Csr RNAs in an opposite manner. A loss of the crp gene resulted in a strong upregulation of CsrB synthesis, whereas CsrC levels were strongly reduced leading to downregulation of the virulence regulator RovA. Switching of the Csr RNA involves Crp-mediated repression of the response regulator UvrY which activates csrB transcription. To elucidate the regulatory links between virulence and carbon metabolism, we performed comparative metabolome, transcriptome and phenotypic microarray analyses and found that Crp promotes oxidative catabolism of many different carbon sources, whereas fermentative patterns of metabolism are favoured when crp is deleted. Mouse infection experiments further demonstrated that Crp is pivotal for a successful Y. pseudotuberculosis infection. In summary, placement of the Csr system and important virulence factors under control of Crp enables this pathogen to link its nutritional status to virulence in order to optimize biological fitness and infection efficiency through the infectious life cycle.
Project description:Expression of the virulence regulator RovA of Yersinia pseudotuberculosis, is controlled by the ncRNAs CsrB and CsrC through CsrA and RovM. In this study, we show that the regulator YmoA of the Hha family of nucleoid-associated proteins controls expression of the counterregulated Csr-type RNAs and the Csr-RovM-RovA signalling cascade through alterations of the CsrC RNA stability. YmoA-mediated stabilization of CsrC depends on CsrA and H-NS, but not on the RNA chaperone Hfq and involves a stabilizing stem-loop structure within the 5M-bM-^@M-^Y-region of CsrC. YmoA influence on CsrC stability is complex as YmoA was found to control numerous factors known to affect RNA structures and stability. In addition, YmoA controls temperature-dependent early and later stage virulence genes in an opposite manner and coregulates their expression with bacterial stress responses and metabolic functions. Following oral infections in a mouse model, we demonstrate that a ymoA mutant is strongly reduced in its ability to disseminate to the PeyerM-bM-^@M-^Ys patches, mesenteric lymph nodes, liver and spleen and exhibits a reduced mortality. We propose a model in which YmoA controls switching from a RovA-dependent early colonization phase towards a virulence plasmid (pYV)-dependent infection phase important for host defense and persistence. For each microarray, 300ng of each Cy3- and Cy5-labelled RNA were mixed, fragmented and hybridized to the microarray at 65M-BM-0C for 17 hours using the Agilent Hybridization Chamber according to the Agilent instructions. Four replicates were performed. Sequences used for the design of the microarray (Agilent, 8 x 15K format) include three different 60-nt oligonucleotides for all 4172 chromosomal genes (ORFs > 30 codons) of the Y. pseudotuberculosis YPIII genome and six probes for the 92 genes of the virulence plasmid pYV of Y. pseudotuberculosis strain IP32953.
Project description:Expression of the virulence regulator RovA of Yersinia pseudotuberculosis, is controlled by the ncRNAs CsrB and CsrC through CsrA and RovM. In this study, we show that the regulator YmoA of the Hha family of nucleoid-associated proteins controls expression of the counterregulated Csr-type RNAs and the Csr-RovM-RovA signalling cascade through alterations of the CsrC RNA stability. YmoA-mediated stabilization of CsrC depends on CsrA and H-NS, but not on the RNA chaperone Hfq and involves a stabilizing stem-loop structure within the 5’-region of CsrC. YmoA influence on CsrC stability is complex as YmoA was found to control numerous factors known to affect RNA structures and stability. In addition, YmoA controls temperature-dependent early and later stage virulence genes in an opposite manner and coregulates their expression with bacterial stress responses and metabolic functions. Following oral infections in a mouse model, we demonstrate that a ymoA mutant is strongly reduced in its ability to disseminate to the Peyer’s patches, mesenteric lymph nodes, liver and spleen and exhibits a reduced mortality. We propose a model in which YmoA controls switching from a RovA-dependent early colonization phase towards a virulence plasmid (pYV)-dependent infection phase important for host defense and persistence.
Project description:Whole transcriptome assessment of the Yersinia pseudotuberculosis strain YPIII. The Y. pseudotuberculosis crp regulon was determined in Yersinia minimal minimum developed for the study. Crp is a key regulator coordinating virulence and metabolism. Y. pseudotuberculosis YPIII or the isogenic crp mutant strain were cultivated at 25M-BM-0C under aeration on a rotary shaker. First pre-cultures were grown in a 1:1 mixture of HAMM-bM-^@M-^Ys F-12 Nutrient Mixture (Invitrogen, Carlsbad, US) and liquid DMEM medium (Biochrom, Berlin, DE). Second pre-cultures and main cultures were grown in a Yersinia minimal medium (YMM). The analysis comprised three biological replicates for each strain. In addition, samples, taken at three different time points of the exponential growth phase, were used to validate constant expression during the cultivation. Total RNA was extracted using SV Total RNA Isolation System (Promega). The samples were treated with RNase-free DNase (Roche Applied Science) and the quality of the RNA was confirmed by the lack of PCR amplification of the hns gene and by using an Agilent 2100 Bioanalyzer.
Project description:Whole transcriptome assessment of the Yersinia pseudotuberculosis strain YPIII. The Y. pseudotuberculosis rovA regulon was determined in Yersinia minimal minimum developed for the study. RovA is a key regulator for Yersinia virulence.
Project description:Whole transcriptome assessment of the Yersinia pseudotuberculosis strain YPIII. The Y. pseudotuberculosis csrA regulon was determined in Yersinia minimal minimum developed for the study. CsrA is a key regulator coordinating virulence and metabolism.