This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Turner, D. P. J. Articles by Ala'Aldeen, D. A. A. Search for Related Content PubMed PubMed Citation Articles by Turner, D. P. J. Articles by Ala'Aldeen, D. A. A.

 Previous Article  |  Next Article 

Infection and Immunity, August 2002, p. 4447-4461, Vol. 70, No. 8
0019-9567/02/$04.00+0     DOI: 10.1128/IAI.70.8.4447-4461.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Autotransported Serine Protease A of Neisseria meningitidis: an Immunogenic, Surface-Exposed Outer Membrane, and Secreted Protein

Molecular Bacteriology and Immunology Research Group, Division of Microbiology and Infectious Diseases, University of Nottingham, Nottingham NG7 2UH, United Kingdom

Received 29 January 2002/ Returned for modification 9 April 2002/ Accepted 13 May 2002

Several autotransporter proteins have previously been identified in Neisseria meningitidis. Using molecular features common to most members of the autotransporter family of proteins, we have identified an additional novel ca. 112-kDa autotransporter protein in the meningococcal genomic sequence data. This protein, designated autotransported serine protease A (AspA), has significant N-terminal homology to the secreted serine proteases (subtilases) from several organisms and contains a serine protease catalytic triad. The amino acid sequence of AspA is well-conserved in serogroup A, B, and C meningococci. In Neisseria gonorrhoeae, the AspA homologue appears to be a pseudogene. The gene encoding AspA was cloned and expressed from meningococcal strain MC58 (B15:P1.16b). Anti-AspA antibodies were detected in patients' convalescent-phase sera, suggesting that AspA is expressed in vivo during infection and is immunogenic and cross-reactive. Rabbit polyclonal monospecific anti-AspA serum was used to probe whole-cell proteins from a panel of wild-type meningococcal strains and two AspA mutant strains. Expression of the ca. 112-kDa precursor polypeptide was detected in 12 of 20 wild-type meningococcal strains examined, suggesting that AspA expression is phase variable. Immunogold electron microscopy and cellular fractionation studies showed that the AspA precursor is transported to the outer membrane and remains surface exposed. Western blot experiments confirmed that smaller, ca. 68- or 70-kDa components of AspA (AspA68 and AspA70, respectively) are then secreted into the meningococcal culture supernatant. Site-directed mutagenesis of S426 abolished secretion of both rAspA68 and rAspA70 in Escherichia coli, confirming that AspA is an autocleaved autotransporter protein. In conclusion, we characterized a novel, surface-exposed and secreted, immunogenic, meningococcal autotransporter protein.

Editor: V. J. DiRita

This article has been cited by other articles:

• Williams, J. N., Skipp, P. J., Humphries, H. E., Christodoulides, M., O'Connor, C. D., Heckels, J. E. (2007). Proteomic Analysis of Outer Membranes and Vesicles from Wild-Type Serogroup B Neisseria meningitidis and a Lipopolysaccharide-Deficient Mutant. Infect. Immun. 75: 1364-1372 [Abstract] [Full Text]  
• Ashgar, S. S. A., Oldfield, N. J., Wooldridge, K. G., Jones, M. A., Irving, G. J., Turner, D. P. J., Ala'Aldeen, D. A. A. (2007). CapA, an Autotransporter Protein of Campylobacter jejuni, Mediates Association with Human Epithelial Cells and Colonization of the Chicken Gut. J. Bacteriol. 189: 1856-1865 [Abstract] [Full Text]  
• Turner, D. P. J., Marietou, A. G., Johnston, L., Ho, K. K. L., Rogers, A. J., Wooldridge, K. G., Ala'Aldeen, D. A. A. (2006). Characterization of MspA, an Immunogenic Autotransporter Protein That Mediates Adhesion to Epithelial and Endothelial Cells in Neisseria meningitidis.. Infect. Immun. 74: 2957-2964 [Abstract] [Full Text]  
• Wooldridge, K. G., Kizil, M., Wells, D. B., Ala'Aldeen, D. A. A. (2005). Unusual Genetic Organization of a Functional Type I Protein Secretion System in Neisseria meningitidis. Infect. Immun. 73: 5554-5567 [Abstract] [Full Text]  
• Litwin, C. M., Johnson, J. M. (2005). Identification, Cloning, and Expression of the CAMP-Like Factor Autotransporter Gene (cfa) of Bartonella henselae. Infect. Immun. 73: 4205-4213 [Abstract] [Full Text]  
• Henderson, I. R., Navarro-Garcia, F., Desvaux, M., Fernandez, R. C., Ala'Aldeen, D. (2004). Type V Protein Secretion Pathway: the Autotransporter Story. Microbiol. Mol. Biol. Rev. 68: 692-744 [Abstract] [Full Text]  
• Fang, C.-T., Chuang, Y.-P., Shun, C.-T., Chang, S.-C., Wang, J.-T. (2004). A Novel Virulence Gene in Klebsiella pneumoniae Strains Causing Primary Liver Abscess and Septic Metastatic Complications. J. Exp. Med. 199: 697-705 [Abstract] [Full Text]  
• Grass, G., Schierhorn, A., Sorkau, E., Muller, H., Rucknagel, P., Nies, D. H., Fricke, B. (2004). Camelysin Is a Novel Surface Metalloproteinase from Bacillus cereus. Infect. Immun. 72: 219-228 [Abstract] [Full Text]  
• Masignani, V., Comanducci, M., Giuliani, M. M., Bambini, S., Adu-Bobie, J., Arico, B., Brunelli, B., Pieri, A., Santini, L., Savino, S., Serruto, D., Litt, D., Kroll, S., Welsch, J. A., Granoff, D. M., Rappuoli, R., Pizza, M. (2003). Vaccination against Neisseria meningitidis Using Three Variants of the Lipoprotein GNA1870. J. Exp. Med. 197: 789-799 [Abstract] [Full Text]