Hfq protein and GcvB small RNA tailoring of target mRNA to levels allowing translation activation by MicF small RNA in .

Traffic of molecules across the bacterial membrane mainly relies on porins and transporters, whose expression must adapt to environmental conditions. To ensure bacterial fitness, synthesis and assembly of functional porins and transporters are regulated through a plethora of mechanisms. Among them, small regulatory RNAs (sRNAs) are known to be powerful post-transcriptional regulators.

Amygdala-driven apnea: A breath of fresh air in respiratory neurobiology.

The amygdala is mainly known for its role in the pathogenesis of anxiety and the initiation of fear responses. However, there is growing evidence showing that the amygdala's ability to respond to internal stimuli such as CO is limited, thereby challenging its role in the brain-behavior relationship. Based on these results and the strong inhibitory connections between the central nucleus of the amygdala and key brainstem areas regulating the reflexive respiratory responses to CO, Feinstein et al.

The small regulatory RNA Lpr10 regulates the expression of RpoS in Legionella pneumophila.

Legionella pneumophila (Lp) is a waterborne bacterium able to infect human alveolar macrophages, causing Legionnaires' disease. Lp can survive for several months in water, while searching for host cells to grow in, such as ciliates and amoeba. In Lp, the sigma factor RpoS is essential for survival in water.

Keeping Up with RNA-Based Regulation in Bacteria: New Roles for RNA Binding Proteins.

RNA binding proteins (RBPs) are ubiquitously found in all kingdoms of life. They are involved in a plethora of regulatory events, ranging from direct regulation of gene expression to guiding modification of RNA molecules. As bacterial regulators, RBPs can act alone or in concert with RNA-based regulators, such as small regulatory RNAs (sRNAs), riboswitches, or clustered regularly interspaced short palindromic repeats (CRISPR) RNAs.

On the Prowl: An In Vivo Method to Identify RNA Partners of a sRNA.

Bacterial cells dispose of numerous strategies to regulate gene expression. Small regulatory RNAs (sRNA) are pervasive molecules that allow gene expression regulation with exquisite precision. These molecules can bind mRNAs and negatively or positively modify their stability and interfere with translation.

Broadening the Definition of Bacterial Small RNAs: Characteristics and Mechanisms of Action.

The first report of trans-acting RNA-based regulation in bacterial cells dates back to 1984. Subsequent studies in diverse bacteria unraveled shared properties of trans-acting small regulatory RNAs, forming a clear definition of these molecules. These shared characteristics have been used extensively to identify new small RNAs (sRNAs) and their interactomes.

Identification of New Bacterial Small RNA Targets Using MS2 Affinity Purification Coupled to RNA Sequencing.

Small regulatory RNAs (sRNAs) are ubiquitous regulatory molecules expressed in living cells. In prokaryotes, sRNAs usually bind to target mRNAs to either promote their degradation or interfere with translation initiation. Because a single sRNA can regulate a considerable number of target mRNAs, we seek to identify those targets rapidly and reliably.

Cellular Homeostasis: A Small RNA at the Crossroads of Iron and Photosynthesis.

The cyanobacterium Synechocystis relies on iron to perform oxygenic photosynthesis. This makes Synechocystis particularly sensitive to iron starvation. A new study shows that the small RNA IsaR1 is a major effector of the iron-stress response, remodeling the photosynthetic apparatus.

A game of tag: MAPS catches up on RNA interactomes.

In the last few decades, small regulatory RNA (sRNA) molecules emerged as key regulators in every kingdom of life. Resolving the full targetome of sRNAs has however remained a challenge. To address this, we used an in vivo tagging MS2-affinity purification protocol coupled with RNA sequencing technology, namely MAPS, to assemble full bacterial small RNAs targetomes.

Every little piece counts: the many faces of tRNA transcripts.

For over half a century, tRNAs have been exclusively known as decoders of genomic information. However, recent reports evidenced that tRNA transcripts are also bearers of functional RNAs, which are able to execute various tasks through an array of mechanisms. Here, we succinctly review the diversity and functions of RNAs deriving from tRNA loci.

DsrA regulatory RNA represses both hns and rbsD mRNAs through distinct mechanisms in Escherichia coli.

The 87 nucleotide long DsrA sRNA has been mostly studied for its translational activation of the transcriptional regulator RpoS. However, it also represses hns mRNA, which encodes H-NS, a major regulator that affects expression of nearly 5% of Escherichia coli genes. A speculative model previously suggested that DsrA would block hns mRNA translation by binding simultaneously to start and stop codon regions of hns mRNA (coaxial model).

A 3' external transcribed spacer in a tRNA transcript acts as a sponge for small RNAs to prevent transcriptional noise.

During ribosomal and transfer RNA maturation, external transcribed spacer (ETS) and internal transcribed spacer (ITS) sequences are excised and, as non-functional by-products, are rapidly degraded. However, we report that the 3'ETS of the glyW-cysT-leuZ polycistronic tRNA precursor is highly and specifically enriched by co-purification with at least two different small regulatory RNAs (sRNAs), RyhB and RybB. Both sRNAs are shown to base pair with the same region in the 3'ETS of leuZ (3'ETS(leuZ)).