ABSTRACT
Extracellular RNA (exRNA) has emerged as an important transducer of intercellular communication. Advancing exRNA research promises to revolutionize biology and transform clinical practice. Recent efforts have led to cutting-edge research and expanded knowledge of this new paradigm in cell-to-cell crosstalk; however, gaps in our understanding of EV heterogeneity and exRNA diversity pose significant challenges for continued development of exRNA diagnostics and therapeutics. To unravel this complexity, the NIH convened expert teams to discuss the current state of the science, define the significant bottlenecks, and brainstorm potential solutions across the entire exRNA research field. The NIH Strategic Workshop on Extracellular RNA Transport helped identify mechanistic and clinical research opportunities for exRNA biology and provided recommendations on high priority areas of research that will advance the exRNA field.
Subject(s)
Cell Communication/genetics , Extracellular Space/metabolism , Gene Expression Regulation/immunology , RNA/metabolism , Animals , Cell Communication/immunology , Congresses as Topic , Disease Models, Animal , Extracellular Space/genetics , Extracellular Space/immunology , Humans , National Institutes of Health (U.S.) , RNA/immunology , Translational Research, Biomedical/methods , United StatesABSTRACT
The intricate regulation of the Escherichia coli rpoS gene, which encodes the stationary phase sigma-factor sigmaS, includes translational activation by the noncoding RNA DsrA. We observed that the stability of rpoS mRNA, and concomitantly the concentration of sigmaS, were significantly higher in an RNase III-deficient mutant. As no decay intermediates corresponding to the in vitro mapped RNase III cleavage site in the rpoS leader could be detected in vivo, the initial RNase III cleavage appears to be decisive for the observed rapid inactivation of rpoS mRNA. In contrast, we show that base-pairing of DsrA with the rpoS leader creates an alternative RNase III cleavage site within the rpoS/DsrA duplex. This study provides new insights into regulation by small regulatory RNAs in that the molecular function of DsrA not only facilitates ribosome loading on rpoS mRNA, but additionally involves an alternative processing of the target.
Subject(s)
Bacterial Proteins/genetics , Bacterial Proteins/metabolism , RNA, Bacterial/genetics , RNA, Bacterial/metabolism , RNA, Untranslated/genetics , RNA, Untranslated/metabolism , Ribonuclease III/metabolism , Sigma Factor/genetics , Sigma Factor/metabolism , Alternative Splicing , Base Sequence , Binding Sites/genetics , DNA Primers/genetics , Escherichia coli/genetics , Escherichia coli/metabolism , Genes, Bacterial , Models, Biological , Molecular Sequence Data , Mutation , RNA Processing, Post-Transcriptional , RNA Stability , RNA, Small Untranslated , Ribonuclease III/genetics , Ribosomes/metabolism , Transcriptional ActivationABSTRACT
To assess the evolutionary conservation of RNA processing pathways in Aquifex aeolicus, we characterized the products of rRNA and tRNA processing that originated from polycistronic transcripts encoded by the A. aeolicus tufA2 and rRNA operons. We found that, similar to its Escherichia coli counterpart, A. aeolicus RNase E/G is involved in rRNA processing and maturation of tRNAs, thus indicating that RNA processing pathways in E. coli and A. aeolicus include common steps and some of them are dependent on RNase E/G. Moreover, although recent biochemical approaches failed to detect an RNase P-like activity in A. aeolicus, our results suggest that such an activity exists in this organism. Accordingly, we show that this activity requires the presence of an RNA component and magnesium ions in order to be detectable in vitro and therefore shares common properties with bacterial RNase P.
