The Twin Arginine Translocation System Is Essential for Aerobic Growth and Full Virulence of Burkholderia thailandensis

Wagley, Sariqa; Hemsley, Claudia; Thomas, Russell J.; Moule, Madeleine G.; Vanaporn, Muthita; Andreae, Clio A.; Robinson, Matthew T.; Goldman, Stan; Wren, Brendan W.; Butler, Catherine; Titball, Richard W.

doi:10.1128/jb.01046-13

Cited by 13 publications

(12 citation statements)

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“…The change in shape of the Δ tatA mutant is likely due to the defect in cell division as was previously described for tat mutations in E. coli, Burkholderia thailandensis , and Helicobacter pylori [25], [46], [47]. In screening the Y. pestis genome for Tat motifs, the Suf1 protein sequence contained a putative Tat signal [58].…”

Section: Discussionmentioning

confidence: 76%

A Yersinia pestis tat Mutant Is Attenuated in Bubonic and Small-Aerosol Pneumonic Challenge Models of Infection but Not As Attenuated by Intranasal Challenge

et al. 2014

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Bacterial proteins destined for the Tat pathway are folded before crossing the inner membrane and are typically identified by an N-terminal signal peptide containing a twin arginine motif. Translocation by the Tat pathway is dependent on the products of genes which encode proteins possessing the binding site of the signal peptide and mediating the actual translocation event. In the fully virulent CO92 strain of Yersinia pestis, the tatA gene was deleted. The mutant was assayed for loss of virulence through various in vitro and in vivo assays. Deletion of the tatA gene resulted in several consequences for the mutant as compared to wild-type. Cell morphology of the mutant bacteria was altered and demonstrated a more elongated form. In addition, while cultures of the mutant strain were able to produce a biofilm, we observed a loss of adhesion of the mutant biofilm structure compared to the biofilm produced by the wild-type strain. Immuno-electron microscopy revealed a partial disruption of the F1 antigen on the surface of the mutant. The virulence of the ΔtatA mutant was assessed in various murine models of plague. The mutant was severely attenuated in the bubonic model with full virulence restored by complementation with the native gene. After small-particle aerosol challenge in a pneumonic model of infection, the mutant was also shown to be attenuated. In contrast, when mice were challenged intranasally with the mutant, very little difference in the LD50 was observed between wild-type and mutant strains. However, an increased time-to-death and delay in bacterial dissemination was observed in mice infected with the ΔtatA mutant as compared to the parent strain. Collectively, these findings demonstrate an essential role for the Tat pathway in the virulence of Y. pestis in bubonic and small-aerosol pneumonic infection but less important role for intranasal challenge.

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Section: Discussionmentioning

confidence: 76%

A Yersinia pestis tat Mutant Is Attenuated in Bubonic and Small-Aerosol Pneumonic Challenge Models of Infection but Not As Attenuated by Intranasal Challenge

et al. 2014

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“…Creation of B. thailandensis arn conditional mutants was carried out by inserting the plasmid pSC200 upstream of either the arn biosynthetic cluster or arn transport cluster ( Figure 1A ) so that the expression of these operons could be regulated by the plasmid-borne inducible rhamnose promoter as previously described ( Ortega et al, 2007 ; Wagley et al, 2014 ). PCR primers are listed in Supplementary Table S2 .…”

Section: Methodsmentioning

confidence: 99%

A Burkholderia thailandensis DedA Family Membrane Protein Is Required for Proton Motive Force Dependent Lipid A Modification

Panta

Doerrler

2021

Front. Microbiol.

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The DedA family is a conserved membrane protein family found in most organisms. A Burkholderia thailandensis DedA family protein, named DbcA, is required for high-level colistin (polymyxin E) resistance, but the mechanism awaits elucidation. Modification of lipopolysaccharide lipid A with the cationic sugar aminoarabinose (Ara4N) is required for colistin resistance and is dependent upon protonmotive force (PMF) dependent transporters. B. thailandensis ΔdbcA lipid A contains only small amounts of Ara4N, likely leading to colistin sensitivity. Two B. thailandensis operons are required for lipid A modification with Ara4N, one needed for biosynthesis of undecaprenyl-P-Ara4N and one for transport of the lipid linked sugar and subsequent lipid A modification. Here, we directed overexpression of each arn operon by genomic insertion of inducible promoters. We found that overexpression of arn operons in ΔdbcA can partially, but not completely, restore Ara4N modification of lipid A and colistin resistance. Artificially increasing the PMF by lowering the pH of the growth media also increased membrane potential, amounts of Ara4N, and colistin resistance of ΔdbcA. In addition, the products of arn operons are essential for acid tolerance, suggesting a physiological function of Ara4N modification. Finally, we show that ΔdbcA is sensitive to bacitracin and expression of a B. thailandensis UppP/BacA homolog (BTH_I1512) can partially restore resistance to bacitracin. Expression of a different UppP/BacA homolog (BTH_I2750) can partially restore colistin resistance, without changing the lipid A profile. This work suggests that maintaining optimal membrane potential at slightly alkaline pH media by DbcA is responsible for proper modification of lipid A by Ara4N and provides evidence of lipid A modification-dependent and -independent mechanisms of colistin resistance in B. thailandensis.

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“…Furthermore, the Tat pathway has also been shown to be essential for the virulence of many different human-, animal-, and plantpathogenic bacteria, such as Pseudomonas aeruginosa (10), P. syringae pv. tomato DC3000 (11), Burkholderia thailandensis (12), Salmonella enterica serovar Enteritidis (13), Campylobacter jejuni (14), and Vibrio cholerae (15). In these pathogens, mutants lacking a functional Tat exhibit different virulence-related phenotypes, such as decreased motility, toxin production, and biofilm formation; sensitivity to detergents and bile; and decreased T3SS secretion, cell growth, and division (16,17).…”

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confidence: 99%

The Tat Substrate SufI Is Critical for the Ability of Yersinia pseudotuberculosis To Cause Systemic Infection

et al. 2017

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The twin arginine translocation (Tat) system targets folded proteins across the inner membrane and is crucial for virulence in many important humanpathogenic bacteria. Tat has been shown to be required for the virulence of Yersinia pseudotuberculosis, and we recently showed that the system is critical for different virulence-related stress responses as well as for iron uptake. In this study, we wanted to address the role of the Tat substrates in in vivo virulence. Therefore, 22 genes encoding potential Tat substrates were mutated, and each mutant was evaluated in a competitive oral infection of mice. Interestingly, a ΔsufI mutant was essentially as attenuated for virulence as the Tat-deficient strain. We also verified that SufI was Tat dependent for membrane/periplasmic localization in Y. pseudotuberculosis. In vivo bioluminescent imaging of orally infected mice revealed that both the ΔsufI and ΔtatC mutants were able to colonize the cecum and Peyer's patches (PPs) and could spread to the mesenteric lymph nodes (MLNs). Importantly, at this point, neither the ΔtatC mutant nor the ΔsufI mutant was able to spread systemically, and they were gradually cleared. Immunostaining of MLNs revealed that both the ΔtatC and ΔsufI mutants were unable to spread from the initial infection foci and appeared to be contained by neutrophils, while wild-type bacteria readily spread to establish multiple foci from day 3 postinfection. Our results show that SufI alone is required for the establishment of systemic infection and is the major cause of the attenuation of the ΔtatC mutant.KEYWORDS Yersinia pseudotuberculosis, Tat pathway, virulence, SufI, mesenteric lymph nodes, neutrophils T he genus Yersinia includes three species that are pathogenic to humans: Yersinia pestis, the causative agent of plague, and the two enteropathogens Y. enterocolitica and Y. pseudotuberculosis, which normally cause a self-limiting disease with symptoms ranging from mild diarrhea, enterocolitis, septicemia, and mesenteric lymphadenitis to reactive arthritis in humans after ingestion of contaminated food or water (1). Once it is ingested, Y. pseudotuberculosis traverses the epithelial barrier through M cells and infects the associated lymphoid tissues, such as Peyer's patches (PPs) and cecal patches, and later spreads to the mesenteric lymph nodes (MLNs). Although the infection is usually self-limited in humans, the infection caused by the two enteropathogenic Yersinia species in mice readily progresses to become systemic and disseminates to the spleen and liver (2). The main virulence arsenal of Yersinia is the type III secretion system (T3SS), which is encoded by an ϳ70-kb virulence plasmid. The T3SS enables the translocation of virulence effector proteins directly into the cytosol of the target host cell, which results in the disruption of host signaling and early immune

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The Twin Arginine Translocation System Is Essential for Aerobic Growth and Full Virulence of Burkholderia thailandensis

Cited by 13 publications

References 58 publications

A Yersinia pestis tat Mutant Is Attenuated in Bubonic and Small-Aerosol Pneumonic Challenge Models of Infection but Not As Attenuated by Intranasal Challenge

A Yersinia pestis tat Mutant Is Attenuated in Bubonic and Small-Aerosol Pneumonic Challenge Models of Infection but Not As Attenuated by Intranasal Challenge

A Burkholderia thailandensis DedA Family Membrane Protein Is Required for Proton Motive Force Dependent Lipid A Modification

The Tat Substrate SufI Is Critical for the Ability of Yersinia pseudotuberculosis To Cause Systemic Infection

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