Small non-coding regulatory RNAs (sRNAs) may act on the translation of a target mRNA, favouring or preventing the formation of secondary structures, so that ribosomes may or not have free access to the RBS. Finally, sRNAs may change the mRNA stability, making it more stable or unstable. A global transcriptomic analysis performed in our laboratory identified C. crescentus genes whose expression was Fur-dependent in response to iron, but also a group of genes differentially expressed in response to iron independently of Fur. These results suggest the existence of a second regulator, probably a regulatory RNA as described for other organisms, and so far no sRNA involved in regulating iron homeostasis has been identified in this bacterium. This project proposes to identify small regulatory RNAs in iron starvation, through global RNA sequencing analysis (RNAseq). This approach allows the identification of differentially expressed genes with more sensitivity than DNA microarrays. Once identified, new RNAseq experiments will be carried out with a null mutant strain for that sRNA, to identifiy its post-transcriptional targets. Translational targets will be identified by mass spectrometry of protein extracts. Finally, the regulatory mechanisms will be determined using mutant strains for the ribonucleases RNase E, RNase R, RNase III, PNPase and Hfq.
News published in Agência FAPESP Newsletter about the scholarship: