Regulatory RNAs in bacteria: From identification to function

Two Small Extracellular Vesicle sRNAs Derived From Mycobacterium tuberculosis Serve as Diagnostic Biomarkers for Active Pulmonary Tuberculosis

“…However, the biological function of the exosomal ASdes and MTB-miR5 remains unknown. Several studies have suggested that M. tuberculosis-encoded sRNA could function as miRNA or long non-coding RNA in the host cells during infection (Masse et al, 2003;Doudna, 2011;Felden and Bouloc, 2017;Cheng and Schorey, 2019). Since the MTB-miR5 was 22 nt and derived from the hairpin structure (Fu et al, 2018), we speculate that it may play a miRNA-like role in the receipting cells.…”

“…Several studies have identified that M. tuberculosis could encode sRNA (Singh et al, 2015;Lv et al, 2017;Fu et al, 2018;Chakrabarty et al, 2019;Lyu et al, 2019). These M. tuberculosis-encoded sRNA play an important role in post-transcriptional regulatory networks during M. tuberculosis infection, mainly through base pairing with mRNA and combining with protein directly (Masse et al, 2003;Gottesman, 2005;Repoila and Darfeuille, 2009;Wagner, 2009;Singh et al, 2015;Felden and Bouloc, 2017). Recently, several reports have suggested that M. tuberculosis encoded sRNA could be secreted into plasma/serum and have the possibility to serve as noninvasive biomarkers for diagnosis of M. tuberculosis infection (Fu et al, 2018;Chakrabarty et al, 2019).…”

Post-transcriptional control of virulence gene expression in Staphylococcus aureus

“…RNAs, RNA degradation, and intra-molecular RNA-RNA interactions to generate the required regulatory flexibility [2].…”

“…One of the most intriguing examples of RNA-mediated post-transcriptional regulation is RNAIII from S. aureus, which with its 14 hairpin structures can interact with, and regulate, a variety of RNA targets involved in virulence [2]. Bacterial mRNAs have short half-lives, typically below 3 minutes [10], and the steady-state level of a given RNA is therefore highly dependent on even minor changes in its degradation rate.…”

“…This realisation has led to the search, in recent years often by transcriptomic methods, for RNAs (or sub-sections of RNAs) with potential regulatory function. A number of excellent recent reviews dealt with the RNA-mediated regulatory mechanisms discovered in various bacteria and have outlined some of the methods used to probe/analyse the molecular details of these regulatory events [2][3][4][5][6].…”