One antitoxin—two functions: SR4 controls toxin mRNA decay and translation

Jahn, Natalie; Brantl, Sabine

doi:10.1093/nar/gkt735

Cited by 48 publications

(87 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An exception is the bifunctional antitoxin SR4 that does not only promote bsrG RNA degradation but also impedes translation by inducing a conformational change around the toxin RBS. 23 However, neither SR5 nor RatA binding alters the structure of the cognate toxin RBS. 25,22 Therefore, we can conclude that SR5 does solely promote Figure 8.…”

Section: Discussion Bsre/sr5 Is a Type I Ta Systemmentioning

confidence: 99%

“…In B. subtilis, 14 type I TA systems were proposed, 21 and 5 of them are located on prophage regions. Of those, txpA/RatA, 8,22 and bsrG/SR4 11,23,24 have been investigated in some detail. bsrG/SR4 is the first temperature sensitive type I TA system, as bsrG RNA is rapidly degraded at 48 C. SR4 is a bifunctional antitoxin that promotes bsrG RNA degradation by recruiting RNase III, and additionally induces a structural change around the bsrG RBS that further obstructs translation.…”

Section: Introductionmentioning

confidence: 99%

“…bsrG/SR4 is the first temperature sensitive type I TA system, as bsrG RNA is rapidly degraded at 48 C. SR4 is a bifunctional antitoxin that promotes bsrG RNA degradation by recruiting RNase III, and additionally induces a structural change around the bsrG RBS that further obstructs translation. 23 The toxin BsrG (38 aa) is recruited to the cell membrane, but surprisingly does neither induce pore formation nor dissipate the membrane potential. Instead, it generates membrane invaginations that cause a delocalization of the cell-wall synthesis machinery, which finally results in autolysis.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A multistress responsive type I toxin-antitoxin system:bsrE/SR5 from theB. subtilischromosome

et al. 2016

Self Cite

View full text Add to dashboard Cite

bsrE/SR5 is a type I TA system from prophage-like element P6 of the B. subtilis chromosome. The 256 nt bsrE RNA encodes a 30 aa toxin. The antitoxin SR5 is a 163 nt antisense RNA. Both genes overlap at their 3 0 ends. Overexpression of bsrE causes cell lysis on agar plates, which can be neutralized by sr5 overexpression, whereas deletion of the chromosomal sr5 copy has no effect. SR5 is short-lived with a halflife of 7 min, whereas bsrE RNA is stable with a half-life of >80 min. The sr5 promoter is 10-fold stronger than the bsrE promoter. SR5 interacts with the 3 0 UTR of bsrE RNA, thereby promoting its degradation by recruiting RNase III. RNase J1 is the main RNase responsible for SR5 and bsrE RNA degradation, and PnpA processes an SR5 precursor to the mature RNA. Hfq stabilizes SR5, but is not required for its inhibitory function. While bsrE RNA is affected by temperature shock and alkaline stress, the amount of SR5 is significantly influenced by various stresses, among them pH, anoxia and iron limitation. Only the latter one is dependent on sigB. Both RNAs are extremely unstable upon ethanol stress due to rapid degradation by RNase Y.

show abstract

Section: Discussion Bsre/sr5 Is a Type I Ta Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A multistress responsive type I toxin-antitoxin system:bsrE/SR5 from theB. subtilischromosome

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…This interaction promotes degradation of the bsrG mRNA through cleavage of the duplex by RNase III and subsequent degradation of the remaining RNAs by endonuclease Y and the 3=-to-5= exoribonuclease R (112). However, RNase III is not essential for the functioning of the toxin-antitoxin system (113), and this might be due to a second role of SR4 in inhibiting bsrG mRNA translation (114). As for the txpA-ratA module, it was suggested that the function of the bsrG-SR4 module is to prevent excision of the SP␤ prophage element from the B. subtilis genome.…”

Section: Independently Expressed Small Rnas and Rna Antitoxinsmentioning

confidence: 99%

Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression

Mars

Nicolas

Denham

et al. 2016

Microbiol Mol Biol Rev

View full text Add to dashboard Cite

SUMMARY Bacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules include trans -acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5′ untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such as Escherichia coli and Salmonella . Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacterium Bacillus subtilis . A recent study identified 1,583 putative regulatory RNAs in B. subtilis , whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation in B. subtilis , and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation in B. subtilis mostly involves elements at the 5′ ends of mRNA molecules. These can include 5′ secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs in B. subtilis . Altogether, the present survey provides many leads for the identification of new regulatory RNA functions in B. subtilis .

show abstract

“…The deletion of sr4 or overexpression of bsrG causes cell lysis on agar plates. SR4 is a bifunctional antitoxin, as it promotes toxin mRNA degradation by an RNase III-dependent mechanism (Jahn et al, 2012) and, additionally, induces a conformational alteration around the bsrG SD sequence impeding ribosome binding (Jahn & Brantl, 2013). Recently, we have shown that the toxin BsrG is recruited to the cell membrane, but surprisingly neither induces pore formation nor causes energy starvation.…”

Section: Introductionmentioning

confidence: 99%

Heat-shock-induced refolding entails rapid degradation of bsrG toxin mRNA by RNases Y and J1

Jahn

Brantl

2016

Microbiology

Self Cite

View full text Add to dashboard Cite

Gene regulation accomplished by alternative folding of an mRNA is a widely used mechanism. Classical examples are the various transcriptional attenuation mechanisms that employ, for example, leader peptide translation, or binding of a modified protein, an uncharged tRNA or an antisense RNA to the 59 untranslated region of an mRNA. With the discovery of transcriptional and translational riboswitches, it became clear that small metabolites or even metal ions can also alter RNA secondary structures and, hence, gene expression. In addition, biophysical factors like temperature can affect RNA folding, as exemplified by RNA thermometers. We have investigated in detail the type I toxin-antitoxin system bsrG/SR4 from Bacillus subtilis. The antitoxin SR4 is a cis-encoded regulatory RNA that neutralizes BsrG toxin action. SR4 prevents toxin expression by promoting degradation of the toxin mRNA and inhibiting its translation. In addition, upon temperature shock the amount of toxin mRNA decreases significantly. Here, we demonstrate that heat shock induces a refolding in the central region of the toxin mRNA that makes it more accessible to degradation by RNases Y and J1. Furthermore, we show that BsrG might play a role at the onset of stationary phase, when the antitoxin SR4 can no longer prevent toxin synthesis.

show abstract

One antitoxin—two functions: SR4 controls toxin mRNA decay and translation

Cited by 48 publications

References 43 publications

A multistress responsive type I toxin-antitoxin system:bsrE/SR5 from theB. subtilischromosome

A multistress responsive type I toxin-antitoxin system:bsrE/SR5 from theB. subtilischromosome

Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression

Heat-shock-induced refolding entails rapid degradation of bsrG toxin mRNA by RNases Y and J1

Contact Info

Product

Resources

About