Identification and type III‐dependent secretion of the <i>Yersinia pestis</i> insecticidal‐like proteins

Gendlina, Inessa; Held, Kiara; Bartra, Sara Schesser; Gallis, Byron; Doneanu, Catalin E.; Plano, Gregory V.; Collins, Carleen

doi:10.1111/j.1365-2958.2007.05729.x

Cited by 43 publications

(63 citation statements)

References 51 publications

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“…Indeed, previous RT-PCR results indicated that there was no expression at 15 u C and thus the Tc complex present in this culture may be an artefact from the initial starter culture, which was grown at 28 u C. Most importantly these Western blots demonstrate that the toxin complex of strain IP32953 is secreted during growth in normal media at all temperatures. This indicates a mechanism independent of the plasmid-borne type III secretion system, which has been previously reported to be responsible for secretion of this complex and is only expressed at 37 u C (Gendlina et al, 2007) proteins. Thus it can be assumed that although this motif may contribute to binding, it does not determine cell specificity.…”

Section: C Hares and Othersmentioning

confidence: 92%

“…However, while Y. pseudotuberculosis is able to colonize the midgut of the rat flea and cause chronic infection, displaying symptoms such as diarrhoea, the heterologously expressed Y. pseudotuberculosis TcaATcaB [A] and TcaCTccC [BC] were found to lack toxicity to the flea. Furthermore, knockouts of these tc genes in Y. pseudotuberculosis strains did not diminish flea toxicity (Erickson et al, 2006(Erickson et al, , 2007 secreted via a type III secretion system indicative of immunomodulatory toxins although no functional data supporting this hypothesis have been published (Gendlina et al, 2007).…”

Section: Introductionmentioning

confidence: 96%

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The Yersinia pseudotuberculosis and Yersinia pestis toxin complex is active against cultured mammalian cells

et al. 2008

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The toxin complex (Tc) genes were first identified in the insect pathogen Photorhabdus luminescens and encode~1 MDa protein complexes which are toxic to insect pests. Subsequent genome sequencing projects have revealed the presence of tc orthologues in a range of bacterial pathogens known to be associated with insects. Interestingly, members of the mammalianpathogenic yersiniae have also been shown to encode Tc orthologues. Studies in Yersinia enterocolitica have shown that divergent tc loci either encode insect-active toxins or play a role in colonization of the gut in gastroenteritis models of rats. So far little is known about the activity of the Tc proteins in the other mammalian-pathogenic yersiniae. Here we present work to suggest that Tc proteins in Yersinia pseudotuberculosis and Yersinia pestis are not insecticidal toxins but have evolved for mammalian pathogenicity. We show that Tc is secreted by Y. pseudotuberculosis strain IP32953 during growth in media at 28 6C and 37 6C. We also demonstrate that oral toxicity of strain IP32953 to Manduca sexta larvae is not due to Tc expression and that lysates of Escherichia coli BL21 expressing the Yersinia Tc proteins are not toxic to Sf9 insect cells but are toxic to cultured mammalian cell lines. Cell lysates of E. coli BL21 expressing the Y. pseudotuberculosis Tc proteins caused actin ruffles, vacuoles and multinucleation in cultured human gut cells (Caco-2); similar morphology was observed after application of a lysate of E. coli BL21 expressing the Y. pestis Tc proteins to mouse fibroblast NIH3T3 cells, but not Caco-2 cells. Finally, transient expression of the individual Tc proteins in Caco-2 and NIH3T3 cell lines reproduced the actin and nuclear rearrangement observed with the topical applications. Together these results add weight to the growing hypothesis that the Tc proteins in Y. pseudotuberculosis and Y. pestis have been adapted for mammalian pathogenicity. We further conclude that Tc proteins from Y. pseudotuberculosis and Y. pestis display differential mammalian cell specificity in their toxicity.

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Section: C Hares and Othersmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 96%

The Yersinia pseudotuberculosis and Yersinia pestis toxin complex is active against cultured mammalian cells

et al. 2008

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“…Using C-terminal glycogen synthase kinase (GSK) epitope tags fused to the N-terminal amino acid residues of the Y. pestis KIM TC-like protein's TCA (YitA and YitB), TCB (YitC), and TCC (YipA and YipB), Gendlina et al (27) identified that the GSK fusions are released by the Y. pestis type III system. The authors also found that under conditions optimal for type III secretion in Y. pseudotuberculosis, YitB could be detected in the culture supernatant.…”

Section: Discussionmentioning

confidence: 99%

The Main Virulence Determinant of Yersinia entomophaga MH96 Is a Broad-Host-Range Toxin Complex Active against Insects

et al. 2011

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Through transposon mutagenesis and DNA sequence analysis, the main disease determinant of the entomopathogenic bacterium Yersinia entomophaga MH96 was localized to an ϳ32-kb pathogenicity island (PAI) designated PAI Ye96 . Residing within PAI Ye96 are seven open reading frames that encode an insecticidal toxin complex (TC), comprising not only the readily recognized toxin complex A (TCA), TCB, and TCC components but also two chitinase proteins that form a composite TC molecule. The central TC gene-associated region (ϳ19 kb) of PAI Ye96 was deleted from the Y. entomophaga MH96 genome, and a subsequent bioassay of the ⌬TC derivative toward Costelytra zealandica larvae showed it to be innocuous. Virulence of the ⌬TC mutant strain could be restored by the introduction of a clone containing the entire PAI Ye96 TC gene region. As much as 0.5 mg of the TC is released per 100 ml of Luria-Bertani broth at 25°C, while at 30 or 37°C, no TC could be detected in the culture supernatant. Filter-sterilized culture supernatants derived from Y. entomophaga MH96, but not from the ⌬TC strain grown at temperatures of 25°C or less, were able to cause mortality. The 50% lethal doses (LD 50 s) of the TC toward diamondback moth Plutella xylostella and C. zealandica larvae were defined as 30 ng and 50 ng, respectively, at 5 days after ingestion. Histological analysis of the effect of the TC toward P. xylostella larva showed that within 48 h after ingestion of the TC, there was a general dissolution of the larval midgut.Toxin complexes (TCs) active on insects were first identified in the nematode-associated bacterium Photorhabdus luminescens and termed TCs, as three proteins combined to form a complex with insecticidal activity (5). TC toxins were subsequently identified in the genome of Serratia entomophila where they reside in the designated gene order sepA, sepB, and sepC (33); this toxin complex ABC designation defines the revised nomenclature of the TC proteins (25). The TC toxins derived from P. luminescens reside as multiple but dissimilar orthologues throughout the P. luminescens T011 genome (22), and different insecticidal activities may be attributed to a different TC cluster (32). The S. entomophila sepABC genes are plasmid borne, and their translated products are host specific, only causing amber disease in larvae of the New Zealand grass grub Costelytra zealandica (Coleoptera: Scarabaeidae) (33). TC-like toxins have since been identified in the genome of Xenorhabdus nematophilus (60), Pseudomonas syringae pv. tomato DC3000 (9), and some Yersinia species. The toxin complex A (TCA)-like (tcaB) gene of Yersinia pestis CO92 contains a frameshift mutation, and the toxin complex B (TCB)-like (tcaC) gene contains an internal deletion (51), indicative of a loss of function, while the corresponding TCA-like and TCBlike orthologues in Y. pestis KIM and 91001 do not (18, 62). Tennant et al. (66) showed that mutations in each of the Yersinia enterocolitica biotype 1A T83 genes, TCA-like (tcbA), TCB-like (tcaC), and TCC-like (tccC) gen...

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“…Our data show that LrhA controls the transcription of this gene and that an xptD1 mutant displays attenuated virulence for M. sexta insects. Recent findings demonstrated that Yersinia pestis TC genes are regulated by YitR, a LysR-type regulator (but not a LrhA homolog) (25) and that the TC can be secreted through the type III secretion pathway. Therefore, it is plausible that, like the secretion of lipase, the X. nematophila TC, including XptD1, is secreted through the flagellar export apparatus.…”

Section: Discussionmentioning

confidence: 99%

Xenorhabdus nematophila lrhAIs Necessary for Motility, Lipase Activity, Toxin Expression, and Virulence inManduca sextaInsects

et al. 2008

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The gram-negative insect pathogen Xenorhabdus nematophila possesses potential virulence factors including an assortment of toxins, degradative enzymes, and regulators of these compounds. Here, we describe the lysR-like homolog A (lrhA) gene, a gene required by X. nematophila for full virulence in Manduca sexta insects. In several other gram-negative bacteria, LrhA homologs are transcriptional regulators involved in the expression (typically repression) of virulence factors. Based on phenotypic and genetic evidence, we report that X. nematophila LrhA has a positive effect on transcription and expression of certain potential virulence factors, including a toxin subunit-encoding gene, xptD1. Furthermore, an lrhA mutant lacks in vitro lipase activity and has reduced swimming motility compared to its wild-type parent. Quantitative PCR revealed that transcript levels of flagellar genes, a lipase gene, and xptD1 were significantly lower in the lrhA mutant than in the wild type. In addition, lrhA itself is positively regulated by the global regulator Lrp. This work establishes a role for LrhA as a vital component of a regulatory hierarchy necessary for X. nematophila pathogenesis and expression of surface-localized and secreted factors. Future research is aimed at identifying and characterizing virulence factors within the LrhA regulon.

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Identification and type III‐dependent secretion of the Yersinia pestis insecticidal‐like proteins

Abstract: SummaryPlague, or the Black Death, is a zoonotic disease that is spread from mammal to mammal by fleas. This mode of transmission demands that the causative agent of this disease, Yersinia pestis, is able to survive and multiply in both mammals and insects. In

Cited by 43 publications

References 51 publications

The Yersinia pseudotuberculosis and Yersinia pestis toxin complex is active against cultured mammalian cells

The Yersinia pseudotuberculosis and Yersinia pestis toxin complex is active against cultured mammalian cells

The Main Virulence Determinant of Yersinia entomophaga MH96 Is a Broad-Host-Range Toxin Complex Active against Insects

Xenorhabdus nematophila lrhAIs Necessary for Motility, Lipase Activity, Toxin Expression, and Virulence inManduca sextaInsects

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