Analysis of virC, an operon involved in the secretion of Yop proteins by Yersinia enterocolitica

Michiels, Thomas; Vanooteghem, J C; Rouvroit, Catherine Lambert de; China, Bernard; Gustin, A; Boudry, Pierre; Cornelis, Guy R.

doi:10.1128/jb.173.16.4994-5009.1991

Cited by 276 publications

(280 citation statements)

References 62 publications

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“…Nevertheless, the Salmonella enterica InvF/SicA and S. flexneri MxiE/IpgC systems appear as clear variations on the same theme, despite the fact that InvF, but not MxiE, controls transcription of the operon encoding its co-activator and translocators. In pathogenic Yersinia species, a feedback regulation on transcription of yop genes by the TTS apparatus activity has been extensively studied (Michiels et al, 1991;Pettersson et al, 1996). In contrast to the Shigella and Salmonella systems, the VP-encoded TTS system of Yersinia species contains only one transcriptional activator, VirF (also a member of the AraC family) (Cornelis et al, 1998).…”

Section: Discussionmentioning

confidence: 99%

Analysis of virulence plasmid gene expression defines three classes of effectors in the type III secretion system of Shigella flexneri

Gall

Mavris

Martino³

et al. 2005

Microbiology

115

174

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Proteins directly involved in entry and dissemination of Shigella flexneri into epithelial cells are encoded by a virulence plasmid of 200 kb. A 30-kb region (designated the entry region) of this plasmid encodes components of a type III secretion (TTS) apparatus, substrates of this apparatus and their dedicated chaperones. During growth of bacteria in broth, expression of these genes is induced at 37 6C and the TTS apparatus is assembled in the bacterial envelope but is not active. Secretion is activated upon contact of bacteria with host cells and is deregulated in an ipaB mutant. The plasmid encodes four transcriptional regulators, VirF, VirB, MxiE and Orf81. VirF controls transcription of virB, whose product is required for transcription of entry region genes. MxiE, with the chaperone IpgC acting as a co-activator, controls expression of several effectors that are induced under conditions of secretion. Genes under the control of Orf81 are not known. The aim of this study was to define further the repertoires of virulence plasmid genes that are under the control of (i) the growth temperature, (ii) each of the known virulence plasmid-encoded transcriptional regulators (VirF, VirB, MxiE and Orf81) and (iii) the activity of the TTS apparatus. Using a macroarray analysis, the expression profiles of 71 plasmid genes were compared in the wild-type strain grown at 37 and 30 6C and in virF, virB, mxiE, ipaB, ipaB mxiE and orf81 mutants grown at 37 6C. Many genes were found to be under the control of VirB and indirectly of VirF. No alteration of expression of any gene was detected in the orf81 mutant. Expression of 13 genes was increased in the secretion-deregulated ipaB mutant in an MxiE-dependent manner. On the basis of their expression profile, substrates of the TTS apparatus can be classified into three categories: (i) those that are controlled by VirB, (ii) those that are controlled by MxiE and (iii) those that are controlled by both VirB and MxiE. The differential regulation of expression of TTS effectors in response to the TTS apparatus activity suggests that different effectors might be required at different times following contact of bacteria with host cells. INTRODUCTIONBacteria of Shigella species are responsible for shigellosis, a human disease characterized by the destruction of the colonic epithelium. Shigellae and enteroinvasive Escherichia coli both contain a virulence plasmid (VP) of approximately 200 kb that encodes most proteins directly involved in entry and dissemination of bacteria into epithelial cells. Sequence analysis of the VP pWR100 (Buchrieser et al., 2000) and its derivative pWR501 (Venkatesan et al., 2001) from a Shigella flexneri strain of serotype 5 and the VP pCP301 (Jin et al., 2002) from an S. flexneri strain of serotype 2a indicated that the VP is composed of a mosaic of approximately 100 genes and numerous insertion sequences. The VP genes exhibit a G+C content from 30 to 60 mol%, suggesting that they were acquired from different sources. The current model of the TTS pathway prop...

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Section: Discussionmentioning

confidence: 99%

Analysis of virulence plasmid gene expression defines three classes of effectors in the type III secretion system of Shigella flexneri

Gall

Mavris

Martino³

et al. 2005

Microbiology

115

174

View full text Add to dashboard Cite

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“…2A). Mutational analysis (Michiels et al, 1991) has demonstrated the requirement for YscL for Yop secretion in Yersinia, but the specific function of this protein has not been elucidated. SsaL.…”

Section: Spi2 Secretion-apparatus Genes 157mentioning

confidence: 99%

Functional analysis of ssaJ and the ssaK/U operon, 13 genes encoding components of the type III secretion apparatus of Salmonella Pathogenicity Island 2

Hensel

Shea

Raupach

et al. 1997

Molecular Microbiology

163

186

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SummaryWe have investigated the structure and transcriptional organization of 13 genes of Salmonella Pathogenicity Island 2 (SPI2) that encode components of the second type III secretion apparatus of Salmonella typhimurium. ssaK, L, M, V, N, O, P, Q, R, S, T, U constitute one operon of 10 kb. ssaJ lies upstream of ssaK and is the terminal gene of another operon. The deduced products of ssaJ, ssaK, ssaV, ssaN, ssaO, ssaQ, ssaR, ssaS, ssaT, and ssaU show greatest similarity to the Yersinia spp. genes yscJ, yscL, lcrD, yscN, yscO, yscQ, yscR, yscS, yscT, and yscU, respectively. The products of the ssaL, ssaM and ssaP genes do not have significant similarity to products of other type III secretion systems, and might be important for the specific function of the SPI2 type III secretion system. Bacterial strains carrying different ssa mutations display minor alterations in terms of serum sensitivity when compared with the wild-type strain, but none are defective in replication within macrophage-like RAW 264.7 cells. However, some of the ssa mutant strains invade HEp2 cells less efficiently and are less cytotoxic to RAW 264.7 macrophages than the wild-type strain. We show that the invasion defect is correlated with a lack of SipC in culture supernatants of these mutant strains.SipC is a product of the SPI1 type III secretion system of S. typhimurium, and is important for epithelial cell invasion. Therefore, mutations in SPI2 can affect the SPI1 secretion system, which raises the possibility of an interaction between the two type III secretion systems.

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“…In addition, a number of pi/Q homologues involved in protein secretion have been reported that are apparently not part of pulC-O-like operons. In the human pathogens Shigella flexneri, Yersinia enterocolitica and Yersinia pestis, homologues of PilQ are necessary for the secretion of various proteins which are significant virulence determinants (Allaoui et al, 1993;Michiels et al, 1991 ;Haddix and Straley, 1992). hrp genes encoding homologues of PilQ have been described in the plant pathogens X. campestris (hrpA 1, Fenselau et al, 1992) , Pseudomonas syringae (hrpH, Huang et al , 1992) and Pseudomonas solanacearum (hrpA , Gough et al, 1992) .…”

Section: Protein Secretionmentioning

confidence: 99%

“…solanacearum HrpA) (Michiels et al, 1991 ;Allaoui et al, 1993;Huang et al, 1992;Gough et al, 1992); and those associated with filamentous phage (M 13 protein IV, Pf3 ORF-430) (van Weezenbeek et al, 1980;Luiten et al , 1985). The remainder, which includes PiIO , Omc, HopO and ORFE (involved in competence in H. influenza e) , form a fourth group that show a high level of sequence similarity, but less obvious functional relationships .…”

Section: Outer Membrane Components (Piiq-like Proteins)mentioning

confidence: 99%

Common components in the assembly of type 4 fimbriae, DNA transfer systems, filamentous phage and protein‐secretion apparatus: a general system for the formation of surface‐associated protein complexes

Hobbs

Mattick

1993

Molecular Microbiology

361

286

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Summary The Pseudomonas aeruginosa genes pilB‐D and pilQ are necessary for the assembly of type 4 fimbriae. Homologues of these genes and of the subunit (pilin) gene have been described in various different bacterial species, but not always in association with type 4 fimbrial biosynthesis and function. Pil‐like proteins are also involved in protein secretion, DNA transfer by conjugation and transformation, and morphogenesis of filamentous bacteriophages. It seems likely that the Pil homologues function in the processing and export of proteins resembling type 4 fimbrial sub‐units, and in their organization into fimbrial‐like structures. These may either be true type 4 fimbriae, or components of protein complexes which act in the transport of macromolecules (DNA or protein) into or out of the cell. Some PilB‐like and PilQ‐like proteins are apparently also involved in the assembly of non‐type 4 polymeric structures (filamentous phage virions and conjugative pili). The diverse studies summarized in this review are providing insight into an extensive infrastructural system which appears to be utilized in the formation of a variety of cell surface‐associated complexes.

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Analysis of virC, an operon involved in the secretion of Yop proteins by Yersinia enterocolitica

Cited by 276 publications

References 62 publications

Analysis of virulence plasmid gene expression defines three classes of effectors in the type III secretion system of Shigella flexneri

Analysis of virulence plasmid gene expression defines three classes of effectors in the type III secretion system of Shigella flexneri

Functional analysis of ssaJ and the ssaK/U operon, 13 genes encoding components of the type III secretion apparatus of Salmonella Pathogenicity Island 2

Common components in the assembly of type 4 fimbriae, DNA transfer systems, filamentous phage and protein‐secretion apparatus: a general system for the formation of surface‐associated protein complexes

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