Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2018

The role of the RNA chaperone ProQ in the Gram-negative bacterium Pasteurella multocida. (#242)

Emily L Gulliver 1 , Brandon Sy 2 , Julia Wong 2 , Deanna Deveson Lucas 1 , Ralf B Schittenhelm 3 , David Powell 4 , Jai Tree 2 , Marina Harper 1 , John Boyce 1
  1. Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Vic, Australia
  2. School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
  3. Monash Biomedical Proteomics Facility, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University , Clayton, Vic, Australia
  4. Monash Bioinformatics Platform, Monash University, Clayton, VIC, Australia

The Gram-negative bacterium Pasteurella multocida is the causative agent of many diseases, including fowl cholera in chickens. One mechanism by which bacteria regulate transcript abundance and protein production is riboregulation, which involves a specific interaction between a small RNA (sRNA) and an mRNA that acts to alter transcript stability and/or translational efficiency. Hfq is a well-characterized RNA chaperone protein that is involved in bacterial riboregulation. Recently, a second RNA chaperone called ProQ was shown to play a critical role in stabilizing some sRNA/mRNA interactions. To assess the role of P. multocida ProQ in riboregulation, we analyzed the transcriptome of a proQ TargeTron® mutant using RNA-seq. In total, 35 transcripts showed increased expression and 96 showed decreased expression. Both sRNAs and tRNAs were highly overrepresented in the set of differentially regulated genes (p = 3.76 x 10-9and p = 3.78 x 10-11, respectively); 17 tRNAs and eight sRNAs showed increased expression and 14 sRNAs showed decreased expression. Direct interactions between ProQ and one sRNA, five tRNAs, and 28 mRNAs involved in the production of ribosomal proteins, were confirmed using UV-crosslinking, ligation, and sequencing of hybrids (UV-CLASH). Several tRNAs formed hybrids with other tRNAs, mRNAs and sRNAs, indicating that these can bind to other RNA species while bound to ProQ. In summary, our results indicate that ProQ binds to many different RNA species, and in particular, to sRNAs and tRNAs. Moreover, transcriptomic analysis indicates that ProQ interaction can stabilize some sRNA species but can destabilize many tRNA species.