Single Protein Production in Living Cells Facilitated by an mRNA Interferase

Suzuki, Motoo; Zhang, Junjie; Liu, Mohan; Woychik, Nancy A.; Inouye, Masayori

doi:10.1016/j.molcel.2005.03.011

Cited by 135 publications

(175 citation statements)

References 29 publications

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“…Indeed, the pentad sequences recognized by MazF-mt3, MazF-mt7, MazF Sa , MazF Bs and MazF-cd are absent in the transcripts of their respective antitoxins [15][16][17]35 . Moreover, toxins other than PemK Sa do not interfere with cell translation machinery 17,36 . Currently, the most important question remaining is whether global analyses of interferase effects on transcriptomes and proteomes will confirm the assumptions concerning their universal regulatory role in bacteria.…”

Section: Discussionmentioning

confidence: 99%

A regulatory role for Staphylococcus aureus toxin–antitoxin system PemIKSa

et al. 2013

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Toxin-antitoxin systems were shown to be involved in plasmid maintenance when they were initially discovered, but other roles have been demonstrated since. Here we identify and characterize a novel toxin-antitoxin system (pemIK Sa ) located on Staphylococcus aureus plasmid pCH91. The toxin (PemK Sa ) is a sequence-specific endoribonuclease recognizing the tetrad sequence UkAUU, and the antitoxin (PemI Sa ) inhibits toxin activity by physical interaction. Although the toxin-antitoxin system is responsible for stable plasmid maintenance our data suggest the participation of pemIK Sa in global regulation of staphylococcal virulence by alteration of the translation of large pools of genes. We propose a common mechanism of reversible activation of toxin-antitoxin systems based on antitoxin transcript resistance to toxin cleavage. Elucidation of this mechanism is particularly interesting because reversible activation is a prerequisite for the proposed general regulatory role of toxin-antitoxin systems.

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Section: Discussionmentioning

confidence: 99%

A regulatory role for Staphylococcus aureus toxin–antitoxin system PemIKSa

et al. 2013

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“…One of the best characterized TA modules is mazEF in Escherichia coli (1)(2)(3)(4)(5)(6)(7), an autoregulated operon that encodes the intracellular toxin MazF and its antitoxin inhibitor MazE. Under unstressed conditions, the MazE protein forms a stable complex with MazF to neutralize its toxicity (1).…”

mentioning

confidence: 99%

“…During times of stress, however, proteases degrade MazE and allow the relatively stable MazF toxin to disrupt protein synthesis (1,2), which can induce a state of reversible dormancy (3). Expression of MazF triggers this quasi-dormant state, during which cells stop dividing but are able to transcribe mRNA and synthesize proteins (4). The striking similarities between this state of quasi-dormancy and the slowgrowing or nonreplicating state of M. tuberculosis during latent tuberculosis (TB) have led to the suggestion that TA modules are involved with persistence and dormancy in M. tuberculosis (8).…”

mentioning

confidence: 99%

Mycobacterial toxin MazF-mt6 inhibits translation through cleavage of 23S rRNA at the ribosomal A site

Schifano

Edifor

Sharp

et al. 2013

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

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The Mycobacterium tuberculosis genome contains an unusually high number of toxin-antitoxin modules, some of which have been suggested to play a role in the establishment and maintenance of latent tuberculosis. Nine of these toxin-antitoxin loci belong to the mazEF family, encoding the intracellular toxin MazF and its antitoxin inhibitor MazE. Nearly every MazF ortholog recognizes a unique three-or five-base RNA sequence and cleaves mRNA. As a result, these toxins selectively target a subset of the transcriptome for degradation and are known as "mRNA interferases." Here we demonstrate that a MazF family member from M. tuberculosis, MazF-mt6, has an additional role-inhibiting translation through targeted cleavage of 23S rRNA in the evolutionarily conserved helix/loop 70. We first determined that MazF-mt6 cleaves mRNA at 5′ UU↓CCU 3′ sequences. We then discovered that MazF-mt6 also cleaves M. tuberculosis 23S rRNA at a single UUCCU in the ribosomal A site that contacts tRNA and ribosome recycling factor. To gain further mechanistic insight, we demonstrated that MazFmt6-mediated cleavage of rRNA can inhibit protein synthesis in the absence of mRNA cleavage. Finally, consistent with the position of 23S rRNA cleavage, MazF-mt6 destabilized 50S-30S ribosomal subunit association. Collectively, these results show that MazF toxins do not universally act as mRNA interferases, because MazF-mt6 inhibits protein synthesis by cleaving 23S rRNA in the ribosome active center.T oxin-antitoxin (TA) systems have the potential to control Mycobacterium tuberculosis growth rate and persistence. One of the best characterized TA modules is mazEF in Escherichia coli (1-7), an autoregulated operon that encodes the intracellular toxin MazF and its antitoxin inhibitor MazE. Under unstressed conditions, the MazE protein forms a stable complex with MazF to neutralize its toxicity (1). During times of stress, however, proteases degrade MazE and allow the relatively stable MazF toxin to disrupt protein synthesis (1, 2), which can induce a state of reversible dormancy (3). Expression of MazF triggers this quasi-dormant state, during which cells stop dividing but are able to transcribe mRNA and synthesize proteins (4). The striking similarities between this state of quasi-dormancy and the slowgrowing or nonreplicating state of M. tuberculosis during latent tuberculosis (TB) have led to the suggestion that TA modules are involved with persistence and dormancy in M. tuberculosis (8).The genome of M. tuberculosis has >80 putative TA pairs (9), a remarkably large number relative to most other prokaryotes. Although TA modules are ubiquitous in bacteria and archaea, few prokaryotes have more than 15 loci (10). Although the physiological role of the large repertoire of TA loci in M. tuberculosis is largely unknown, some clues have emerged. First, there is an inverse correlation between the number of chromosomal TA loci and growth rate (10). Second, more than 60 TA toxins are conserved between five members of the M. tuberculosis complex but not in 13 oth...

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“…Chromosomal TA systems appear to be responsible for the phenotypic switch to a quasidormant state that enables cell survival during stress (e.g., antibiotic treatment, UV exposure, temperature extremes or nutrient deprivation) (3). This quasidormant state can be rapidly reversed if the stressor is removed within a certain window of time, triggering the production of antitoxin that sequesters free toxin.…”

mentioning

confidence: 99%

Bacterial addiction module toxin Doc inhibits translation elongation through its association with the 30S ribosomal subunit

Liu¹,

Zhang²,

Inouye³

et al. 2008

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

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117

103

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Bacterial toxin-antitoxin (TA) systems (or ''addiction modules'') typically facilitate cell survival during intervals of stress by inducing a state of reversible growth arrest. However, upon prolonged stress, TA toxin action leads to cell death. TA systems have also been implicated in several clinically important phenomena: biofilm formation, bacterial persistence during antibiotic treatment, and bacterial pathogenesis. TA systems harbored by pathogens also serve as attractive antibiotic targets. To date, the mechanism of action of the majority of known TA toxins has not yet been elucidated. We determined the mode of action of the Doc toxin of the Phd-Doc TA system. Doc expression resulted in rapid cell growth arrest and marked inhibition of translation without significant perturbation of transcription or replication. However, Doc did not cleave mRNA as do other addiction-module toxins whose activities result in translation inhibition. Instead, Doc induction mimicked the effects of treatment with the aminoglycoside antibiotic hygromycin B (HygB): Both Doc and HygB interacted with 30S ribosomal subunits, stabilized polysomes, and resulted in a significant increase in mRNA half-life. HygB also competed with ribosome-bound Doc, whereas HygB-resistant mutants suppressed Doc toxicity, suggesting that the Doc-binding site includes that of HygB (i.e., helix 44 region of 16S rRNA containing the A, P, and E sites). Overall, our results illuminate an intracellular target and mechanism of TA toxin action drawn from aminoglycoside antibiotics: Doc toxicity is the result of inhibition of translation elongation, possibly at the translocation step, through its interaction with the 30S ribosomal subunit.antitoxin ͉ hygromycin B ͉ bacteriophage P1 ͉ 16S rRNA ͉ postsegregational killing

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Single Protein Production in Living Cells Facilitated by an mRNA Interferase

Cited by 135 publications

References 29 publications

A regulatory role for Staphylococcus aureus toxin–antitoxin system PemIKSa

A regulatory role for Staphylococcus aureus toxin–antitoxin system PemIKSa

Mycobacterial toxin MazF-mt6 inhibits translation through cleavage of 23S rRNA at the ribosomal A site

Bacterial addiction module toxin Doc inhibits translation elongation through its association with the 30S ribosomal subunit

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