Synthesis of staphylococcal virulence factors is controlled by a regulatory RNA molecule.

Novick, Richard P.; Ross, Hope F.; Projan, Steven J.; Kornblum, John; Kreiswirth, Barry N.; Moghazeh, Soraya L.

doi:10.1002/j.1460-2075.1993.tb06074.x

Cited by 930 publications

(940 citation statements)

References 46 publications

Supporting

Mentioning

910

Contrasting

Unclassified

Order By: Relevance

“…The primary focus on the regulation of toxin gene expression in S. aureus has been on the agr operon containing three promoters (P1, P2, and a divergently oriented promoter, P3) (30,31,33). The levels of the majority of the extracellular toxins are significantly elevated during the postexponential phase.…”

Section: Resultsmentioning

confidence: 99%

Alternative transcription factor sigmaSB of Staphylococcus aureus: characterization and role in transcription of the global regulatory locus sar

1997

View full text Add to dashboard Cite

A homolog of the multiple-stress-responsive transcription factor B of Bacillus subtilis was predicted from the DNA sequence analysis of a region of the Staphylococcus aureus chromosome. A hybrid between the coding sequence of the first 11 amino acids of the gene 10 leader peptide of phage T7 (T7.Tag) and the putative sigB gene of S. aureus was constructed and cloned into Escherichia coli BL21(DE3)pLysS for overexpression from a T7 promoter. A homogeneous preparation of the overproduced protein was obtained by affinity chromatography with a T7.Tag monoclonal antibody coupled to agarose. The amino-terminal amino acid sequence of the first 22 residues of the purified protein matched that deduced from the nucleotide sequence. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified protein, designated SB , indicated that it migrated as an approximately 39-kDa polypeptide. Promoter-specific transcription from the B. subtilis B -dependent P B promoter of the sigB operon was stimulated by SB in a concentration-dependent fashion when reconstituted with the S. aureus core RNA polymerase (RNAP). Specific transcript from the predicted B -dependent P B promoter of the sigB operon of S. aureus was obtained by the reconstituted RNAP in a runoff transcription reaction. The sar operon of S. aureus contains three promoter elements (P1, P2, and P3) and is known to partly control the synthesis of a number of extracellular toxins and several cell wall proteins. Our in vitro studies revealed that transcription from the P1 promoter is dependent on the primary factor SA , while that of the P3 promoter is dependent on SB . As determined by primer extension studies, the 5 end of the SB -initiated mRNA synthesized in vitro from the sar P3 promoter is in agreement with the 5 end of the cellular RNA.In prokaryotes, several factors coexist in cells (19,22,24). The transcription factors evolutionarily related to Escherichia coli 70 are subdivided into two groups (15). The primary factor is required for the expression of housekeeping genes whose products are essential for exponential cell growth. The level or the activity of the second group, comprising the alternate factors, has been shown to be modulated in response to environmental and metabolic stresses. The core RNA polymerase (RNAP) associated with a particular factor initiates transcription from a specific set of promoters with conserved sequence motifs. B , identified in sporulating Bacillus subtilis, is the first member of the alternate factors to be reported in prokaryotes (20,21). Much has been learnt recently about the regulation of expression of the sigB operon and the modulation of the function of the SigB ( B ) protein in response to changing stress (entry into stationary growth phase, nutrient depletion, and presence of uncouplers of oxidative phosphorylation) and environmental stress (heat shock and osmotic shock) in B. subtilis (2,6,8,22,36,37,41).The emergence of multiple-drug-resistant, highly pathogenic strains of Staphylococcus aureus poses a serious thr...

show abstract

Section: Resultsmentioning

confidence: 99%

Alternative transcription factor sigmaSB of Staphylococcus aureus: characterization and role in transcription of the global regulatory locus sar

1997

View full text Add to dashboard Cite

show abstract

“…The expression of all psm genes is controlled by the Agr system for quorum sensing (8,(11)(12)(13). This system modulates gene expression such that cell wall-associated virulence factors (e.g., the immunoglobulin G-binding protein A) are most highly expressed at low cell densities and that secreted virulence factors (e.g., the PSMs) are most highly expressed at high cell densities (14)(15)(16)(17)(18)(19)(20)(21).…”

Section: S Taphylococcus Aureus Is An Opportunistic Human Pathogen Thatmentioning

confidence: 99%

Distinct Roles of Phenol-Soluble Modulins in Spreading of Staphylococcus aureus on Wet Surfaces

Tsompanidou

Denham

Becher

et al. 2013

Appl Environ Microbiol

View full text Add to dashboard Cite

The human pathogen Staphylococcus aureus is renowned for the rapid colonization of contaminated wounds, medical implants, and food products. Nevertheless, little is known about the mechanisms that allow S. aureus to colonize the respective wet surfaces. The present studies were therefore aimed at identifying factors used by S. aureus cells to spread over wet surfaces, starting either from planktonic or biofilm-associated states. Through proteomics analyses we pinpoint phenol-soluble modulins (PSMs) as prime facilitators of the spreading process. To dissect the roles of the eight PSMs produced by S. aureus, these peptides were chemically synthesized and tested in spreading assays with different psm mutant strains. The results show that PSM␣3 and PSM␥ are the strongest facilitators of spreading both for planktonic cells and cells in catheter-associated biofilms. Compared to the six other PSMs of S. aureus, PSM␣3 and PSM␥ combine strong surfactant activities with a relatively low overall hydropathicity. Importantly, we show that PSM-mediated motility of S. aureus facilitates the rapid colonization of wet surfaces next to catheters and the colonization of fresh meat. S taphylococcus aureus is an opportunistic human pathogen thatcan cause a wide range of acute and chronic diseases, which range from superficial skin infections to life-threatening endocarditis and sepsis (1, 2). The ability of this Gram-positive bacterium to cause these infections depends on the production of secreted and cell wall-associated virulence factors. Of increasing concern is the ability of S. aureus to acquire resistance against antibiotics, as underscored by the global spread of methicillin-resistant S. aureus (MRSA) lineages.Intriguingly, recent proteomics studies have revealed an enormous diversity in the production of virulence factors by different isolates of S. aureus, and only a few of these seem to be invariantly produced (3-5). Among the most commonly identified staphylococcal virulence factors, especially in the community-associated (CA)-MRSA lineages, are the so-called phenol-soluble modulins (PSMs) (6). These PSMs are short, amphipathic, ␣-helical peptides that have leukocidal activity and biosurfactant properties (7-9). The growth media of S. aureus cultures contain both N-terminally formylated and deformylated PSMs, suggesting that these virulence factors are substrates for the bacterial N-formylmethionine deformylase (9, 10).To date, eight PSMs have been identified in S. aureus. These include the four PSM␣1 to PSM␣4 peptides (22 residues each), the PSM␤1 and PSM␤2 peptides (44 residues each), PSM␥ (25 residues) and the recently reported PSM-mec (22 residues). The PSM␣ peptides are encoded by the psm␣ operon, the PSM␤ peptides by the psm␤ operon, and PSM␥ by the hld gene. Notably, the hld gene is embedded within the regulatory RNAIII molecule that is encoded by the agr locus. The gene for PSM-mec was identified in MRSA strains carrying the staphylococcal cassette chromosome mec (SCCmec) types II or III. The expression of all ps...

show abstract

“…The agr locus is composed of two divergent transcription units designated RNAII (agrA, -B, -C, and -D genes) and RNAIII (hld gene). Mutation in either agrA or agrB has led to decreased transcription of RNAIII (11,16). RNAIII, which also encodes the 26-residue 8-hemolysin polypeptide, is essential for the transcriptional control of exoprotein synthesis (e.g., a hemolysin) (11).…”

mentioning

confidence: 99%

Cloning and sequencing of sarA of Staphylococcus aureus, a gene required for the expression of agr

1994

View full text Add to dashboard Cite

To evaluate the effect of a sar mutation on the agr locus, Northern (RNA) blotting was performed to determine the levels of RNAIII, the agr regulatory molecule, in two isogenic pairs of Staphylococcus aureus strains. Our results demonstrated that RNAIII was either significantly diminished or absent in both sar mutants compared with the parents. The RNAIII level was partially restored in sar mutants complemented with an intact sar gene (designated sarA). Additionally, we were able to complement selected sar phenotypes with a plasmid carrying RNAIII (pRN6735). These studies suggest that the sarA gene is necessary for the optimal expression of agr. The sarA gene of strain RN450 was subsequently cloned and sequenced. Sequence analysis revealed an open reading frame of372 bp with a predicted molecular size of 14,718 Da and a deduced pI of 8.52. The deduced protein sequence has a predominance of charged residues (33%) and shares sequence similarity with the virF gene of Shigella flexneri.

show abstract

Synthesis of staphylococcal virulence factors is controlled by a regulatory RNA molecule.

Cited by 930 publications

References 46 publications

Alternative transcription factor sigmaSB of Staphylococcus aureus: characterization and role in transcription of the global regulatory locus sar

Alternative transcription factor sigmaSB of Staphylococcus aureus: characterization and role in transcription of the global regulatory locus sar

Distinct Roles of Phenol-Soluble Modulins in Spreading of Staphylococcus aureus on Wet Surfaces

Cloning and sequencing of sarA of Staphylococcus aureus, a gene required for the expression of agr

Contact Info

Product

Resources

About