USIAS Fellows seminar - The power of cooperation: characterising the functions of bacterial sRNAs

By Wolfgang R. Hess and Pascale Romby (2017 FRIAS-USIAS Fellows)

Bacteria have to constantly adapt their metabolism and growth to ever-changing environmental conditions. These fast adaptive events require the coordinated action of many regulatory factors, which involve transcriptional factors, metabolite-sensing proteins, RNA-binding proteins, and small non-coding RNAs (sRNA) to regulate gene expression at multiple levels. There are hundreds of different sRNAs in a typical bacterium, which in contrast to eukaryotic miRNAs are more heterogeneous in length, sequence composition, and secondary structure. The vast majority of sRNAs function post-transcriptionally by binding to other RNAs (mRNAs, sRNAs) through rather short regions of imperfect sequence complementarity. In addition, every single sRNA may interact with dozens of different target RNAs and impact gene expression either negatively or positively. These facts contributed to the view that the entirety of the regulatory targets of a given sRNA, its targetome, is challenging to identify.

The collaboration between the two teams in Freiburg and Strasbourg shows that a better appreciation of the sRNA-dependent regulatory networks can be achieved through the combination of experimental and computational approaches. Wolfgang Hess and Pascale Romby will give a short introduction to these methods, followed by a description of several examples illustrating the particular strengths and weaknesses of these approaches in more detail. As examples, they will show how sRNAs connect stress response and metabolism adaptation to virulence in Staphylococcus aureus.