A 3′ External Transcribed Spacer in a tRNA Transcript Acts as a Sponge for Small RNAs to Prevent Transcriptional Noise

The end is not the end: remnants of tRNA precursors live on to sponge up small regulatory RNAs

Natural RNA sponges sequestering cellular noncoding RNA molecules have been found in diverse organisms. In this issue, Lalaouna et al. (2015) report another type of RNA sponge, showing that stable intermediates of bacterial tRNA processing control endogenous small RNAs.

Identification of sRNA interacting with a transcript of interest using MS2-affinity purification coupled with RNA sequencing (MAPS) technology

RNA sequencing (RNAseq) technology recently allowed the identification of thousands of small RNAs (sRNAs) within the prokaryotic kingdom. However, drawing the comprehensive interaction map of a sRNA remains a challenging task. To address this problem, we recently developed a method called MAPS (MS2 affinity purification coupled with RNA sequencing) to characterize the full targetome of specific sRNAs. This method enabled the identification of target RNAs interacting with sRNAs, regardless of the type of regulation (positive or negative), type of targets (mRNA, tRNA, sRNA) or their abundance. We also demonstrated that we can use this technology to perform a reverse MAPS experiment, where an RNA fragment of interest is used as bait to identify interacting sRNAs. Here, we demonstrated that RybB and MicF sRNAs co-purified with internal transcribed spacers (ITS) of metZ–metW–metV tRNA transcript, confirming results obtained with MS2-RybB MAPS.

Both raw and analyzed RNAseq data are available in GEO database (GSE66517).