The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
Gene Review

virG  -  invasion protein

Shigella flexneri 5a str. M90T

Synonyms: S0192, icSA
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of virG

  • The ability of Shigella to spread within and between epithelial cells is a prerequisite for causing bacillary dysentery and requires the function encoded by the virG gene on the large plasmid [1].
  • A novel virulence gene (virA) was identified upstream of the virG gene on the large plasmid of Shigella flexneri 2a YSH6000 [2].
  • Further characterization of delta aroA delta virG Shigella flexneri 2a strain CVD 1203 as a mucosal Shigella vaccine and as a live-vector vaccine for delivering antigens of enterotoxigenic Escherichia coli [3].
  • EcSf2a-3 was derived from EcSf2a-2 by introducing a deletion in the virG gene, whose expression is required for plaque formation and keratoconjunctivitis in guinea pigs [4].
  • To express human papillomavirus (HPV) L1 capsid protein in the recombinant strain of Shigella and study the potential of a live attenuated Shigella-based HPV prophylactic vaccine in preventing HPV infection, the icsA/virG fragment of Shigella-based prokaryotic expression plasmid pHS3199 was constructed [5].

High impact information on virG

  • We have identified a region (virG) on the 230 kb virulence plasmid of S. flexneri that is required for cell-to-cell spread of the bacterium [6].
  • The virG region was localized to within 4 kb and may contain a single cistron [6].
  • Identification of icsA, a plasmid locus of Shigella flexneri that governs bacterial intra- and intercellular spread through interaction with F-actin [7].
  • The nucleotide sequence of the virA region revealed that the virA gene was located 528 bp upstream of the virG gene, in the opposite orientation [2].
  • In contrast, the activation of the virG gene necessary for intercellular spread occurred directly by virF without the requirement for virB [8].

Chemical compound and disease context of virG

  • The Shigella flexneri 2a SC602 vaccine candidate carries deletions of the plasmid-borne virulence gene icsA (mediating intra- and intercellular spread) and the chromosomal locus iuc (encoding aerobactin) (S. Barzu, A. Fontaine, P. J. Sansonetti, and A. Phalipon, Infect. Immun. 64:1190-1196, 1996) [9].

Biological context of virG

  • The observed phenotype of M94 in the cytoplasm indicated that the virG locus is not required for multiplication of the invading shigellae, but is essential for their spread to adjacent cells [10].
  • Characterization of the vacC mutant indicated that levels of VirG, a protein essential for bacterial spreading, and VirF, the positive regulator for the expression of the virG and ipaBCD operons, decreased significantly compared with those of the wild type [11].
  • The nucleotide sequence of 4,472 bp, which contains the functional virG gene and its own regulatory sequence, was determined, and a large open reading frame encoding 1,102 amino acid residues was identified [10].
  • Results obtained from molecular genetic studies, mainly of the genes, virG, virF and kcpA are discussed [12].

Anatomical context of virG

  • A stable strain, S. sonnei Mosely, was selected for further work. pDeltavirG2, a deletion derivative of the virG gene in the sacB suicide vector pCVD442, was used to generate an S. sonnei virG deletion strain, WRSS1, which was invasive in HeLa cells but negative in the Sereny test [13].
  • This vaccine strain was constructed by deletion of virulence genes responsible for dissemination (icsA) and survival (iuc:iut) of bacteria within the colonic mucosa [14].

Other interactions of virG


  1. Extracellular transport of VirG protein in Shigella. Suzuki, T., Lett, M.C., Sasakawa, C. J. Biol. Chem. (1995) [Pubmed]
  2. Identification of a novel virulence gene, virA, on the large plasmid of Shigella, involved in invasion and intercellular spreading. Uchiya, K., Tobe, T., Komatsu, K., Suzuki, T., Watarai, M., Fukuda, I., Yoshikawa, M., Sasakawa, C. Mol. Microbiol. (1995) [Pubmed]
  3. Further characterization of delta aroA delta virG Shigella flexneri 2a strain CVD 1203 as a mucosal Shigella vaccine and as a live-vector vaccine for delivering antigens of enterotoxigenic Escherichia coli. Noriega, F.R., Losonsky, G., Wang, J.Y., Formal, S.B., Levine, M.M. Infect. Immun. (1996) [Pubmed]
  4. Construction and characterization of virG (icsA)-deleted Escherichia coli K12-Shigella flexneri hybrid vaccine strains. Alexander, W.A., Hartman, A.B., Oaks, E.V., Venkatesan, M.M. Vaccine (1996) [Pubmed]
  5. Construction of prophylactic human papillomavirus type 16 L1 capsid protein vaccine delivered by live attenuated Shigella flexneri strain sh42. Yang, X.F., Qu, X.Z., Wang, K., Zheng, J., Si, L.S., Dong, X.P., Wang, Y.L. Acta Biochim. Biophys. Sin. (Shanghai) (2005) [Pubmed]
  6. A genetic determinant required for continuous reinfection of adjacent cells on large plasmid in S. flexneri 2a. Makino, S., Sasakawa, C., Kamata, K., Kurata, T., Yoshikawa, M. Cell (1986) [Pubmed]
  7. Identification of icsA, a plasmid locus of Shigella flexneri that governs bacterial intra- and intercellular spread through interaction with F-actin. Bernardini, M.L., Mounier, J., d'Hauteville, H., Coquis-Rondon, M., Sansonetti, P.J. Proc. Natl. Acad. Sci. U.S.A. (1989) [Pubmed]
  8. A dual transcriptional activation system for the 230 kb plasmid genes coding for virulence-associated antigens of Shigella flexneri. Adler, B., Sasakawa, C., Tobe, T., Makino, S., Komatsu, K., Yoshikawa, M. Mol. Microbiol. (1989) [Pubmed]
  9. Vaccination against shigellosis with attenuated Shigella flexneri 2a strain SC602. Coster, T.S., Hoge, C.W., VanDeVerg, L.L., Hartman, A.B., Oaks, E.V., Venkatesan, M.M., Cohen, D., Robin, G., Fontaine-Thompson, A., Sansonetti, P.J., Hale, T.L. Infect. Immun. (1999) [Pubmed]
  10. virG, a plasmid-coded virulence gene of Shigella flexneri: identification of the virG protein and determination of the complete coding sequence. Lett, M.C., Sasakawa, C., Okada, N., Sakai, T., Makino, S., Yamada, M., Komatsu, K., Yoshikawa, M. J. Bacteriol. (1989) [Pubmed]
  11. vacC, a virulence-associated chromosomal locus of Shigella flexneri, is homologous to tgt, a gene encoding tRNA-guanine transglycosylase (Tgt) of Escherichia coli K-12. Durand, J.M., Okada, N., Tobe, T., Watarai, M., Fukuda, I., Suzuki, T., Nakata, N., Komatsu, K., Yoshikawa, M., Sasakawa, C. J. Bacteriol. (1994) [Pubmed]
  12. Molecular genetic approaches to the pathogenesis of bacillary dysentery. Yoshikawa, M., Sasakawa, C., Makino, S., Okada, N., Lett, M.C., Sakai, T., Yamada, M., Komatsu, K., Kamata, K., Kurata, T. Microbiol. Sci. (1988) [Pubmed]
  13. Construction of a stable attenuated Shigella sonnei DeltavirG vaccine strain, WRSS1, and protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model. Hartman, A.B., Venkatesan, M.M. Infect. Immun. (1998) [Pubmed]
  14. Induction of a local anti-IpaC antibody response in mice by use of a Shigella flexneri 2a vaccine candidate: implications for use of IpaC as a protein carrier. Barzu, S., Fontaine, A., Sansonetti, P., Phalipon, A. Infect. Immun. (1996) [Pubmed]
  15. Identification of cpxR as a positive regulator essential for expression of the Shigella sonnei virF gene. Nakayama, S., Watanabe, H. J. Bacteriol. (1998) [Pubmed]
WikiGenes - Universities