Intracellular expression of the Salmonella plasmid virulence protein, SpvB, causes apoptotic cell death in eukaryotic cells

Kurita, Ai; Gotoh, Hiroki; Eguchi, M.; Okada, Nobuhiko; Matsuura, S.; Matsui, Hidenori; Danbara, Hirofumi; Kikuchi, Yuji

doi:10.1016/s0882-4010(03)00066-4

Cited by 40 publications

(32 citation statements)

References 27 publications

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“…Strains harboring inactive SpvB do not induce apoptosis (9). In line with these observations, Kurita and coworkers reported that ADP-ribosylation of actin by SpvB triggers cell death of macrophage-like cells with many features of apoptosis (23). However, the mechanism leading to SpvB-mediated apoptosis is still not precisely known.…”

Section: Vol 76 2008 Actin Adp-ribosylation By C2 Toxin Delays Apopmentioning

confidence: 83%

ADP-Ribosylation of Actin by the Clostridium botulinum C2 Toxin in Mammalian Cells Results in Delayed Caspase-Dependent Apoptotic Cell Death

et al. 2008

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The binary C2 toxin from Clostridium botulinum mono-ADP-ribosylates G-actin in the cytosol of eukaryotic cells. This modification leads to depolymerization of actin filaments accompanied by cell rounding within 3 h of incubation but does not immediately induce cell death. Here we investigated the long-term responses of mammalian cell lines (HeLa and Vero) following C2 toxin treatment. Cells stayed round even though the toxin was removed from the medium after its internalization into the cells. No unmodified actin reappeared in the C2 toxin-treated cells within 48 h. Despite actin being completely ADP-ribosylated after about 7 h, no obvious decrease in the overall amount of actin was observed for at least 48 h. Therefore, ADP-ribosylation was not a signal for an accelerated degradation of actin in the tested cell lines. C2 toxin treatment resulted in delayed apoptotic cell death that became detectable about 15 to 24 h after toxin application in a portion of the cells. Poly(ADP)-ribosyltransferase 1 (PARP-1) was cleaved in C2 toxin-treated cells, an indication of caspase 3 activation and a hallmark of apoptosis. Furthermore, specific caspase inhibitors prevented C2 toxin-induced apoptosis, implying that caspases 8 and 9 were activated in C2 toxin-treated cells. C2I, the ADP-ribosyltransferase component of the C2 toxin, remained active in the cytosol for at least 48 h, and no extensive degradation of C2I was observed. From our data, we conclude that the long-lived nature of C2I in the host cell cytosol was essential for the nonreversible cytotoxic effect of C2 toxin, resulting in delayed apoptosis of the tested mammalian cells.Clostridium botulinum C2 toxin, the prototype of the family of binary actin ADP-ribosylating toxins, mono-ADP-ribosylates G-actin at Arg-177 (1). C2 toxin consists of the enzyme component C2I (431 amino acid residues, 49.3 kDa) and the binding/translocation component C2II (721 amino acid residues, 80.8 kDa). The ADP-ribosyltransferase activity of C2I is located in its C-terminal domain (5), while the enzymatically inactive N-terminal domain (C2IN, amino acid residues 1 to 225) mediates interaction with C2IIa and translocation of C2I into the cytosol (6). Following limited proteolysis, the active C2IIa protein (ϳ60 kDa) forms ring-shaped heptamers that assemble with C2I and mediate binding of the toxin complex to the cellular receptor, a carbohydrate structure (2, 11, 19). During cellular uptake, the heptamers form pores in endosomal membranes, thereby facilitating translocation of C2I into the cytosol (7). Translocation of C2I requires unfolding (14) and subsequent refolding of the protein in the cytosol by the host cell chaperone Hsp90 (13).In the cytosol, C2I catalyzes covalent transfer of the ADPribose moiety from NAD (NAD ϩ ) to Arg-177 of G-actin (1). Mono-ADP-ribosylation of actin induces the depolymerization of F-actin and thereby a complete loss of actin filaments, resulting in rounding of cultured monolayer cells (1). The ADPribosylation at Arg-177 turns G-actin monomers into "cappin...

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Section: Vol 76 2008 Actin Adp-ribosylation By C2 Toxin Delays Apopmentioning

confidence: 83%

ADP-Ribosylation of Actin by the Clostridium botulinum C2 Toxin in Mammalian Cells Results in Delayed Caspase-Dependent Apoptotic Cell Death

et al. 2008

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“…spvA is the first gene of the spvABCD operon located in the Salmonella virulence plasmid. This operon is essential for Salmonella to establish a successful systemic infection, and this phenotype has been ascribed mainly to spvB expression (7,9,18,25). STM2689 has recently been renamed bapA and codes for a large proline-threonine-rich protein involved in biofilm formation and invasion (27).…”

Section: Resultsmentioning

confidence: 99%

Induction of RpoS Degradation by the Two-Component System Regulator RstA in Salmonella enterica

2007

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Bacterial survival in diverse and changing environments relies on the accurate interplay between different regulatory pathways, which determine the design of an adequate adaptive response. The proper outcome depends on a precise gene expression profile generated from the finely tuned and concerted action of transcriptional factors of distinct regulatory hierarchies. Salmonella enterica serovar Typhimurium harbors multiple regulatory systems that are crucial for the bacterium to cope with harsh extra-and intracellular environments. In this work, we found that the expression of Salmonella RstA, a response regulator from the two-component system family, was able to downregulate the expression of three RpoS-controlled genes (narZ, spvA, and bapA). Furthermore, this downregulation was achieved by a reduction in RpoS cellular levels. The alternative sigma factor RpoS is critical for bacterial endurance under the most-stressful conditions, including stationary-phase entrance and host adaptation. Accordingly, RpoS cellular levels are tightly controlled by complex transcriptional, translational, and posttranslational mechanisms. The analysis of each regulatory step revealed that in Salmonella, RstA expression was able to promote RpoS degradation independently of the MviA-ClpXP proteolytic pathway. Additionally, we show that RstA is involved in modulating Salmonella biofilm formation. The fact that the RpoS-modulated genes affected by RstA expression have previously been demonstrated to contribute to Salmonella pathogenic traits, which include biofilm-forming capacity, suggests that under yet unknown conditions, RstA may function as a control point of RpoS-dependent pathways that govern Salmonella virulence.RstA is a member of the OmpR subfamily of two-component system (TCS) response regulators (RRs), characterized by the display of a winged-helix-turn-helix motif in the DNAbinding domain. Several lines of evidence demonstrated that in Escherichia coli, the encoding gene, rstA, belongs to the PhoP/ PhoQ regulon (39) showing downregulation of rstAB (which codes for the putative RstA/RstB TCS putative pair) in a phoPQ mutant strain and direct PhoP control over rstA expression by a footprinting assay (34). Yamamoto et al. showed that RstB, the putative RstA-associated histidine kinase, was able to transfer in vitro its phosphoryl group to RstA (53), suggesting that in E. coli, RstB and RstA constitute an orthodox TCS regulatory pair. Phenotypic screenings, either systematically deleting the genes that code for TCS or overexpressing all RRs, indicated that E. coli rstAB was involved in bacterial resistance to ketoprofen, pridinol, and troleandomycin (54) and that RstA overexpression conferred low-level ␤-lactam resistance (20). More recently, it was shown that in E. coli, the transient expression of RpoE (sigma E) in stationary phase downregulated rstA and rstB transcription (22) and that multiple copies of rstA suppressed the lethal phenotype of a deletion in yjeE, encoding an ATPase with undetermined function (6). While thi...

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“…Intracellular expression of the SpvB protein induces not only disruption of actin filaments, but also apoptotic cell death in eukaryotic cells. 3,24,25 We found a gene sequence that is homologous to spvB on the pR ST98 plasmid. However, pR ST98 is a large chimeric plasmid containing complex sequences of unknown functions.…”

Section: S Typhi Plasmid Induces Macrophage Apoptosismentioning

confidence: 91%

“…Although the exact contribution of virulence plasmids to pathogenesis is still a matter of debate, progress has been made in identifying regions of the plasmid that are necessary for conferring virulence. Kurita et al 3 identified a highly conserved region of 8 kb, designated the Salmonella plasmid virulence (spv) genes; these genes are present in the plasmids of all other pathogenic Salmonella spp. except S. typhi.…”

Section: Introductionmentioning

confidence: 99%

A Salmonella enterica serovar Typhi plasmid induces rapid and massive apoptosis in infected macrophages

et al. 2010

Cell Mol Immunol

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pR ST98 is a chimeric plasmid isolated from Salmonella enterica serovar Typhi (S. typhi) that mediates the functions of drug resistance and virulence. Previously, we reported that Salmonella plasmid virulence (spv) genes were present in S. typhi. In our current study, we investigated whether plasmid pR ST98 exhibits significant cytotoxicity in macrophages. pR ST98 was transferred into the avirulent Salmonella enterica serovar Typhimurium (S. typhimurium) strain RIA to create the transconjugant pR ST98 /RIA. The standard S. typhimurium virulent strain SR-11, which carries a 100-kb virulence plasmid, was used as a positive control. The bacterial strains were incubated with a murine macrophage-like cell line (J774A.1) in vitro. Apoptosis of J774A.1 cells was examined by electron microscopy and flow cytometry after annexin-V/propidium iodide labeling, and the survival of Salmonella strains in J774A.1 cells was determined. Results showed that macrophages infected with strain pR ST98 /RIA displayed greater levels of apoptosis than those infected with RIA and that pR ST98 may increase bacterial survival in macrophages. Further studies showed that the pR ST98 -induced death of macrophages was associated with the loss of mitochondrial membrane potential and that pR ST98 may activate caspase-9 and then caspase-3. The research data indicate that the virulence of bacteria that contain the pR ST98 plasmid is enhanced; the presence of this plasmid increases the survival of the bacterial pathogen and acts through the mitochondrial pathway to mediate macrophage apoptosis.

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Intracellular expression of the Salmonella plasmid virulence protein, SpvB, causes apoptotic cell death in eukaryotic cells

Cited by 40 publications

References 27 publications

ADP-Ribosylation of Actin by the Clostridium botulinum C2 Toxin in Mammalian Cells Results in Delayed Caspase-Dependent Apoptotic Cell Death

ADP-Ribosylation of Actin by the Clostridium botulinum C2 Toxin in Mammalian Cells Results in Delayed Caspase-Dependent Apoptotic Cell Death

Induction of RpoS Degradation by the Two-Component System Regulator RstA in Salmonella enterica

A Salmonella enterica serovar Typhi plasmid induces rapid and massive apoptosis in infected macrophages

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