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.
Project description:Bordetella pertussis has been shown to encode regulatory RNAs, yet the post-transcriptional regulatory circuits on which they act remain to be fully elucidated. We generated mutants lacking the endonucleases RNase III and RNase E and assessed their individual impact on the B. pertussis transcriptome. RNA-Seq analysis showed differential expression of ~25% of the B. pertussis transcriptome in each mutant with only 28% overlap between data sets. Both endonucleases exhibited substantial impact on genes involved in amino acid uptake e.g. ABC transporters, and in virulence e.g. the type III secretion system, and the autotransporters vag8, tcfA and brkA. Interestingly, mutations in RNase III and RNase E drove the stability of many transcripts, including those involved in virulence, in opposite directions; a result that was validated by qPCR and immunoblot for tcfA and brkA. Of note, whereas similar mutations to RNase E in E. coli have subtle effects on transcript stability, a striking >20-fold reduction in four gene transcripts, including tcfA and vag8, was observed in B. pertussis. We further compared our data set to the regulon controlled by the RNA chaperone Hfq to identify B. pertussis loci influenced by regulatory RNAs. This analysis identified ~120 genes and 19 operons potentially regulated at the post-transcriptional level. Thus, our findings revealed how changes in RNase III- and RNase E-mediated RNA turnover influence pathways associated with virulence and cellular homeostasis. Moreover, we highlighted loci potentially influenced by regulatory RNAs, providing insights into the post-transcriptional regulatory networks involved in fine tuning B. pertussis gene expression.
Project description:Comparative genome hybridization (CGH) of sample of 58 Bordetella bronchiseptica, B. pertussis, and B. parapertussis strains selected to span four clusters as defined by MLST.
Project description:Genomic content of Bordetella pertussis clinical isolates circulating in areas of intensive children vaccination. 13 isolates and one reference strain of Bordetella pertussis used.
