Regulation of virulence gene expression in<i>Streptococcus pyogenes</i>

Bugrysheva, Julia V.; Scott, June R.

doi:10.4161/rna.7.5.13097

Cited by 13 publications

(13 citation statements)

References 23 publications

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“…For instance, a group of transcripts encoding virulence proteins ( e.g . Streptolysin S and Streptodornase D) are highly stable during stationary growth phase as their degradation – by RNases J1/J2 and PNPase – is delayed compared to other mRNAs [41,42]. It was proposed that the differences in RNA decay initiation of these two groups of mRNAs rely on features ( e.g .…”

Section: Discussionmentioning

confidence: 99%

“…It was proposed that the differences in RNA decay initiation of these two groups of mRNAs rely on features ( e.g . secondary structures) in the mRNA 5′ UTRs [42]. However, other unidentified requirements, apart from the 5′ UTR, are also needed to discriminate the different sets of mRNAs to allow differential stability of virulence-related mRNAs [31].…”

Section: Discussionmentioning

confidence: 99%

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RNase Y-mediated regulation of the streptococcal pyrogenic exotoxin B

et al. 2018

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Endoribonuclease Y (RNase Y) is a crucial regulator of virulence in Gram-positive bacteria. In the human pathogen Streptococcus pyogenes, RNase Y is required for the expression of the major secreted virulence factor streptococcal pyrogenic exotoxin B (SpeB), but the mechanism involved in this regulation remains elusive. Here, we demonstrate that the 5′ untranslated region of speB mRNA is processed by several RNases including RNase Y. In particular, we identify two RNase Y cleavage sites located downstream of a guanosine (G) residue. To assess whether this nucleotide is required for RNase Y activity in vivo, we mutated it and demonstrate that the presence of this G residue is essential for the processing of the speB mRNA 5′ UTR by RNase Y. Although RNase Y directly targets and processes speB, we show that RNase Y-mediated regulation of speB expression occurs primarily at the transcriptional level and independently of the processing in the speB mRNA 5′ UTR. To conclude, we demonstrate for the first time that RNase Y processing of an mRNA target requires the presence of a G. We also provide new insights on the speB 5′ UTR and on the role of RNase Y in speB regulation.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

RNase Y-mediated regulation of the streptococcal pyrogenic exotoxin B

et al. 2018

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“…The half-life of bacterial mRNA is estimated to be between 0.5 and 20 min, but different RNA transcripts degrade at different rates. Studies with S. pyogenes have shown that degradation of transcripts can be broadly grouped into two classes (Bugrysheva & Scott, 2010). Information concerning the half-life of the transcripts used in this study was not available; however, all RNA samples were handled and maintained in a manner designed to minimize degradation, as recommended (Promega).…”

Section: Discussionmentioning

confidence: 99%

Manuka honey inhibits the development of Streptococcus pyogenes biofilms and causes reduced expression of two fibronectin binding proteins

et al. 2012

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Streptococcus pyogenes (group A Streptococcus; GAS) is always of clinical significance in wounds where it can initiate infection, destroy skin grafts and persist as a biofilm. Manuka honey has broad spectrum antimicrobial activity and its use in the clinical setting is beginning to gain acceptance with the continuing emergence of antibiotic resistance and the inadequacy of established systemic therapies; novel inhibitors may affect clinical practice. In this study, the effect of manuka honey on S. pyogenes (M28) was investigated in vitro with planktonic and biofilm cultures using MIC, MBC, microscopy and aggregation efficiency. Bactericidal effects were found in both planktonic cultures and biofilms, although higher concentrations of manuka honey were needed to inhibit biofilms. Abrogation of adherence and intercellular aggregation was observed. Manuka honey permeated 24 h established biofilms of S. pyogenes, resulting in significant cell death and dissociation of cells from the biofilm. Sublethal concentrations of manuka honey effectively prevented the binding of S. pyogenes to the human tissue protein fibronectin, but did not inhibit binding to fibrinogen. The observed inhibition of fibronectin binding was confirmed by a reduction in the expression of genes encoding two major fibronectin-binding streptococcal surface proteins, Sof and SfbI. These findings indicate that manuka honey has potential in the topical treatment of wounds containing S. pyogenes. INTRODUCTIONStreptococcus pyogenes (group A Streptococcus) colonizes the nasopharynx and skin of healthy individuals, forming part of the commensal microbiota. Under appropriate conditions, S. pyogenes can be transmitted to wounds and is especially problematic after surgery, following skin grafting and for military personal with traumatic or puncture wounds. Wounds provide a route of entry to the host and damaged tissues display a matrix of proteins including collagen, albumin, fibronectin and fibrinogen, which collectively provide a plethora of ligands to which opportunistic pathogens, including streptococci, adhere (Kubo et al., 2001). Surgical site infection accounts for approximately 25 % of all hospital-acquired infections and may result in the development of a non-healing or chronic wound (Werdin et al., 2009). Non-healing wounds are defined as wounds that have failed to proceed through the normal, orderly and timely reparative process that results in restoration of anatomical and functional integrity, within 3 months (Cooper, 2005;Guo & Dipietro, 2010). In the developed world, approximately 1-1.5 % of populations have non-healing wounds, and these account for 2-4 % of all health care expenses (Gottrup, 2008).Biofilms have been associated with persistent or chronic wound infections and are a major obstacle to healing (James et al., 2008;Rhoads et al., 2008). Streptococcus species readily form biofilms, by a process in which numerous cell-wall-anchored adhesins specifically attach to human tissue protein ligands and promote bacterial aggregation (Nobbs et ...

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“…Class I transcripts are unstable in both exponential and stationary phase, whereas class II mRNAs that code for a number of virulence related proteins are resistant to nucleolytic attack for up to 20 min in stationary phase before being degraded. It has been proposed that RNases J1 and J2 initiate decay through endonucleolytic cleavage [77, 165]. In their model, the authors suggest that class I transcripts are efficient substrates that titrate RNase J before becoming available to cleave class II mRNAs.…”

Section: The Direct Entry Pathwaymentioning

confidence: 99%

Initiation of mRNA decay in bacteria

Laalami

Zig

Putzer

2013

Cell. Mol. Life Sci.

118

109

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The instability of messenger RNA is fundamental to the control of gene expression. In bacteria, mRNA degradation generally follows an “all-or-none” pattern. This implies that if control is to be efficient, it must occur at the initiating (and presumably rate-limiting) step of the degradation process. Studies of E. coli and B. subtilis, species separated by 3 billion years of evolution, have revealed the principal and very disparate enzymes involved in this process in the two organisms. The early view that mRNA decay in these two model organisms is radically different has given way to new models that can be resumed by “different enzymes—similar strategies”. The recent characterization of key ribonucleases sheds light on an impressive case of convergent evolution that illustrates that the surprisingly similar functions of these totally unrelated enzymes are of general importance to RNA metabolism in bacteria. We now know that the major mRNA decay pathways initiate with an endonucleolytic cleavage in E. coli and B. subtilis and probably in many of the currently known bacteria for which these organisms are considered representative. We will discuss here the different pathways of eubacterial mRNA decay, describe the major players and summarize the events that can precede and/or favor nucleolytic inactivation of a mRNA, notably the role of the 5′ end and translation initiation. Finally, we will discuss the role of subcellular compartmentalization of transcription, translation, and the RNA degradation machinery.

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Regulation of virulence gene expression inStreptococcus pyogenes

Cited by 13 publications

References 23 publications

RNase Y-mediated regulation of the streptococcal pyrogenic exotoxin B

RNase Y-mediated regulation of the streptococcal pyrogenic exotoxin B

Manuka honey inhibits the development of Streptococcus pyogenes biofilms and causes reduced expression of two fibronectin binding proteins

Initiation of mRNA decay in bacteria

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