Similar Datasets
Project description:By shaping gene expression profiles, small RNAs (sRNAs) enable bacteria to efficiently adapt to changes in their environment. To better understand how Escherichia coli acclimatizes to nutrient availability, we performed UV cross-linking, ligation and sequencing of hybrids (CLASH) to uncover Hfq-associated RNA-RNA interactions at specific growth stages. We demonstrate that Hfq CLASH robustly captures bona fide RNA-RNA interactions. We identified hundreds of novel sRNA base-pairing interactions, including many sRNA-sRNA interactions and involving 3'UTR-derived sRNAs. We rediscovered known and identified novel sRNA seed sequences. The sRNA-mRNA interactions identified by CLASH have strong base-pairing potential and are highly enriched for complementary sequence motifs, even those supported by only a few reads. Yet, steady state levels of most mRNA targets were not significantly affected upon over-expression of the sRNA regulator. Our results reinforce the idea that the reproducibility of the interaction, not base-pairing potential, is a stronger predictor for a regulatory outcome.
| S-EPMC7213987 | biostudies-literature
Project description:By shaping gene expression profiles, small RNAs (sRNAs) enable bacteria to efficiently adapt to changes in their environment. To better understand how Escherichia coli acclimatizes to nutrient availability, we performed UV cross-linking, ligation and sequencing of hybrids (CLASH) to uncover Hfq-associated RNA-RNA interactions at specific growth stages. We demonstrate that Hfq CLASH robustly captures bona fide RNA-RNA interactions identified hundreds of novel sRNA base-pairing interactions, including many sRNA-sRNA interactions and involving 3’UTR-derived sRNAs. We rediscovered known and identified novel sRNA seed sequences. The sRNA-mRNA interactions identified by CLASH have strong base-pairing potential and are highly enriched for complementary sequence motifs, even those supported by only a few reads. Yet, steady state levels of most mRNA targets were not significantly affected upon over-expression of the sRNA regulator. Our results reinforce the idea that the reproducibility of the interaction, not base-pairing potential, is a stronger predictor for a regulatory outcome.
2020-05-01 | GSE123049 | GEO
Project description:By shaping gene expression profiles, small RNAs (sRNAs) enable bacteria to efficiently adapt to changes in their environment. To better understand how Escherichia coli acclimatizes to nutrient availability, we performed UV cross-linking, ligation and sequencing of hybrids (CLASH) to uncover Hfq-associated RNA-RNA interactions at specific growth stages. We demonstrate that Hfq CLASH robustly captures bona fide RNA-RNA interactions identified hundreds of novel sRNA base-pairing interactions, including many sRNA-sRNA interactions and involving 3’UTR-derived sRNAs. We rediscovered known and identified novel sRNA seed sequences. The sRNA-mRNA interactions identified by CLASH have strong base-pairing potential and are highly enriched for complementary sequence motifs, even those supported by only a few reads. Yet, steady state levels of most mRNA targets were not significantly affected upon over-expression of the sRNA regulator. Our results reinforce the idea that the reproducibility of the interaction, not base-pairing potential, is a stronger predictor for a regulatory outcome.
2020-05-01 | GSE123048 | GEO
Project description:Hfq CLASH uncovers sRNA-target interaction networks linked to nutrient availability adaptation [CLASH]
| PRJNA507415 | ENA
Project description:Hfq CLASH uncovers sRNA-target interaction networks linked to nutrient availability adaptation
| PRJNA507412 | ENA
Project description:Hfq CLASH uncovers sRNA-target interaction networks linked to nutrient availability adaptation [RNA-seq]
| PRJNA507414 | ENA
Project description:Many bacteria use small RNAs (sRNAs) and the RNA chaperone Hfq to regulate mRNA stability and translation. Hfq, a ring-shaped homohexamer, has multiple faces that can bind both sRNAs and their mRNA targets. We find that Hfq has at least two distinct ways in which it interacts with sRNAs; these different binding properties have strong effects on the stability of the sRNA in vivo and the sequence requirements of regulated mRNAs. Class I sRNAs depend on proximal and rim Hfq sites for stability and turn over rapidly. Class II sRNAs are more stable and depend on the proximal and distal Hfq sites for stabilization. Using deletions and chimeras, we find that while Class I sRNAs regulate mRNA targets with previously defined ARN repeats, Class II sRNAs regulate mRNAs carrying UA-rich rim-binding sites. We discuss how these different binding modes may correlate with different roles in the cell, with Class I sRNAs acting as emergency responders and Class II sRNAs acting as silencers.
| S-EPMC4609186 | biostudies-other
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen responsible for high levels of human morbidity and mortality. MRSA co-ordinates expression of an array of bacterial factors involved in antimicrobial resistance, nutrient acquisition and immune evasion in the host. Post-transcriptional regulation by small RNAs (sRNAs) has emerged as an important mechanism for the control of MRSA virulence. However, the function of the majority of sRNAs during infection is unknown. To address this gap in understanding, we performed UV cross-linking, ligation and sequencing of hybrids (CLASH) in MRSA to unravel sRNA-RNA interactions under conditions that mimic the host environment. Using double stranded ribonuclease III (RNase III) as a bait we not only uncovered known interactions but also hundreds of novel sRNA-RNA pairs. Strikingly, our results suggest that the production of small membrane-permeabilizing toxins is under extensive sRNA-mediated regulation and that their expression is intimately connected to metabolism. Importantly, we discovered that two sRNAs, RNAIII and RsaE, control the expression of at least four cytolytic toxins that are important for MRSA virulence. Taken together, we present a comprehensive analysis of sRNA-target interactions in S. aureus and provide detail on how these contribute to the control of virulence in response to changes in metabolism.
2022-05-04 | GSE166151 | GEO
Project description:Methicillin resistant Staphylococcus aureus (MRSA) is an infectious pathogen that poses a significant threat to human health. MRSA is renowned for its ability to adapt to and even thrive in hostile environment within its host. By expressing a battery of virulence factors and toxins, MRSA is able to scavenge effectively essential nutrients and evade the immune system within the host. Post-transcriptional regulation by sRNAs contributes significantly to regulating the expression of virulence factors and toxins. However, the roles of the vast majority of sRNAs during host adaptation remain unknown. To challenge this gap, we performed UV cross-linking, ligation and sequencing of hybrids (CLASH) in S. aureus to unravel sRNA-RNA interactions with the double stranded ribonuclease III (RNase III) as a bait under conditions that mimic the host environment. Here we report a global analysis of RNA-RNA interactions in MRSA in vivo, which uncovered hundreds of novel sRNA-RNA pairs. Strikingly, our results indicate that the production of small membrane-permeabilizing toxins is under extensive sRNA-mediated regulation and that their expression is intimately connected to metabolism. We show that at least two sRNAs, RNAIII and RsaE, enhance the production of five clinically relevant cytolytic toxins that are important for survival within the host. Taken together, our data greatly expands the repertoire of sRNA-target interactions in S. aureus and provide detail on how these contribute to adjusting virulence in response to changes in metabolism.
2022-06-16 | PXD025122 | Pride
Project description:Small RNAs post-transcriptionally regulate many processes in bacteria. Base-pairing of sRNAs near ribosome-binding sites in mRNAs inhibits translation, often requiring the RNA chaperone Hfq. In the canonical model, Hfq simultaneously binds sRNAs and mRNA targets to accelerate pairing. Here, we show that the Escherichia coli sRNAs OmrA and OmrB inhibit translation of the diguanylate cyclase DgcM (previously: YdaM), a player in biofilm regulation. In OmrA/B repression of dgcM, Hfq is not required as an RNA interaction platform, but rather unfolds an inhibitory RNA structure that impedes OmrA/B binding. This restructuring involves distal face binding of Hfq and is supported by RNA structure mapping. A corresponding mutant protein cannot support inhibition in vitro and in vivo; proximal and rim mutations have negligible effects. Strikingly, OmrA/B-dependent translational inhibition in vitro is restored, in complete absence of Hfq, by a deoxyoligoribonucleotide that base-pairs to the biochemically mapped Hfq site in dgcM mRNA We suggest that Hfq-dependent RNA structure remodeling can promote sRNA access, which represents a mechanism distinct from an interaction platform model.
| S-EPMC6443205 | biostudies-literature