Effect of Hfq on RprA−<i>rpoS</i> mRNA Pairing: Hfq−RNA Binding and the Influence of the 5′ <i>rpoS</i> mRNA Leader Region

Updegrove, Taylor B.; Wilf, Nabil M.; Sun, Xiao‐Man; Wartell, Roger M.

doi:10.1021/bi800479p

Cited by 62 publications

(99 citation statements)

References 41 publications

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“…Sun and Wartell found that RprA binding to rpoS mRNA also depends on an extended 5′ leader in vitro (24). Our in vivo results now demonstrate that the same ðAANÞ 4 site within the extended 5′ leader is critical for activation of rpoS translation by both RprA and ArcZ.…”

Section: Resultssupporting

confidence: 59%

See 1 more Smart Citation

Positive regulation by small RNAs and the role of Hfq

Soper

Mandin

Majdalani

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

253

300

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Bacterial small noncoding RNAs carry out both positive and negative regulation of gene expression by pairing with mRNAs; in Escherichia coli, this regulation often requires the RNA chaperone Hfq. Three small regulatory RNAs (sRNAs), DsrA, RprA, and ArcZ, positively regulate translation of the sigma factor RpoS, each pairing with the 5′ leader to open up an inhibitory hairpin. In vitro, rpoS interaction with sRNAs depends upon an ðAANÞ 4 Hfq-binding site upstream of the pairing region. Here we show that both Hfq and this Hfq binding site are required for RprA or ArcZ to act in vivo and to form a stable complex with rpoS mRNA in vitro; both were partially dispensable for DsrA at 37°C. ArcZ sRNA is processed from 121 nt to a stable 56 nt species that contains the pairing region; only the 56 nt ArcZ makes a strong Hfq-dependent complex with rpoS. For each of these sRNAs, the stability of the sRNA • mRNA complexes, rather than their rate of formation, best predicted in vivo activity. These studies demonstrate that binding of Hfq to the rpoS mRNA is critical for sRNA regulation under normal conditions, but if the stability of the sRNA • mRNA complex is sufficiently high, the requirement for Hfq can be bypassed.Sigma 38 | translational control | Sm-like protein | RNA-protein interactions

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Section: Resultssupporting

confidence: 59%

“…A long 5′ leader was found to be essential for Hfqdependent annealing of these sRNAs to rpoS mRNA (23,24). Hfq binds the rpoS leader site specifically, increases the rate of rpoS mRNA • DsrA base pairing 30 to 50-fold, and stabilizes the final mRNA • sRNA complex in vitro (23).…”

mentioning

confidence: 99%

Positive regulation by small RNAs and the role of Hfq

Soper

Mandin

Majdalani

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

253

300

View full text Add to dashboard Cite

show abstract

“…The function of RprA as a posttranscriptional activator of σ S synthesis has been well established in E. coli (20,21,25,26). By contrast, this "core" sRNA, which is conserved in many enterobacterial species, was reported to have little if any role in the closely related pathogen, Salmonella Typhimurium (27), although both RprA and its target region in the rpoS mRNA are fully conserved (28,29).…”

Section: Resultsmentioning

confidence: 99%

Small RNA-based feedforward loop with AND-gate logic regulates extrachromosomal DNA transfer in Salmonella

Papenfort

Espinosa

Casadesús

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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Horizontal gene transfer via plasmid conjugation is a major driving force in microbial evolution but constitutes a complex process that requires synchronization with the physiological state of the host bacteria. Although several host transcription factors are known to regulate plasmid-borne transfer genes, RNA-based regulatory circuits for host-plasmid communication remain unknown. We describe a posttranscriptional mechanism whereby the Hfq-dependent small RNA, RprA, inhibits transfer of pSLT, the virulence plasmid of Salmonella enterica. RprA employs two separate seed-pairing domains to activate the mRNAs of both the sigma-factor σ S and the RicI protein, a previously uncharacterized membrane protein here shown to inhibit conjugation. Transcription of ricI requires σ S and, together, RprA and σ S orchestrate a coherent feedforward loop with AND-gate logic to tightly control the activation of RicI synthesis. RicI interacts with the conjugation apparatus protein TraV and limits plasmid transfer under membrane-damaging conditions. To our knowledge, this study reports the first small RNA-controlled feedforward loop relying on posttranscriptional activation of two independent targets and an unexpected role of the conserved RprA small RNA in controlling extrachromosomal DNA transfer.RprA | sRNA | feedforward control | plasmid conjugation | Hfq

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“…While the mechanism of action for OxyS has not been solved yet, base pairing of DsrA and RprA to the 5' region of the rpoS mRNA was analyzed in detail. 8,9,13 Therefore it has to be considered that some competition of the different small RNAs for pairing to rpoS mRNA and/ or binding of Hfq may take place and influence degradation rates. Since expression levels of OxyS in the absence of hydrogen peroxide are too low in order to determine half-lives, all experiments were performed at 37°C in the presence of hydrogen peroxide.…”

Section: Resultsmentioning

confidence: 99%

“…8,9 Therefore, translational rates of rpoS are increased, when the levels of DsrA or RprA increase. DsrA is 85 nt long and produced at about 30 fold higher level at 25°C than at 42°C.…”

Section: Introductionmentioning

confidence: 99%