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 Couturier, M. R. Articles by Stein, M. Search for Related Content PubMed PubMed Citation Articles by Couturier, M. R. Articles by Stein, M.

 Previous Article  |  Next Article 

Infection and Immunity, January 2006, p. 273-281, Vol. 74, No. 1
0019-9567/06/$08.00+0     doi:10.1128/IAI.74.1.273-281.2006
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Interaction with CagF Is Required for Translocation of CagA into the Host via the Helicobacter pylori Type IV Secretion System

Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2R3, Canada,¹ Dipartimento di Biologia, Biomediche Sperimentali, Universita di Padova, Via G Colombo 3, Padova, Italy²

Received 22 July 2005/ Returned for modification 17 August 2005/ Accepted 14 October 2005

Development of severe gastric diseases is strongly associated with those strains of Helicobacter pylori that contain the cag pathogenicity island (PAI) inserted into the chromosome. The cag PAI encodes a type IV secretion system that translocates the major disease-associated virulence protein, CagA, into the host epithelial cell. CagA then affects host signaling pathways, leading to cell elongations and inflammation. Since the precise mechanism by which the CagA toxin is translocated by the type IV secretion system remained elusive, we used fusion proteins and immunoprecipitation studies to identify CagA-interacting secretion components. Here we demonstrate that CagA, in addition to other yet-unidentified proteins, interacts with CagF, presumably at the inner bacterial membrane. This interaction is required for CagA translocation, since an isogenic nonpolar cagF mutant was translocation deficient. Our results suggest that CagF may be a protein with unique chaperone-like function that is involved in the early steps of CagA recognition and delivery into the type IV secretion channel.

Editor: D. L. Burns

This article has been cited by other articles:

• Kutter, S., Buhrdorf, R., Haas, J., Schneider-Brachert, W., Haas, R., Fischer, W. (2008). Protein Subassemblies of the Helicobacter pylori Cag Type IV Secretion System Revealed by Localization and Interaction Studies. J. Bacteriol. 190: 2161-2171 [Abstract] [Full Text]  
• Pattis, I., Weiss, E., Laugks, R., Haas, R., Fischer, W. (2007). The Helicobacter pylori CagF protein is a type IV secretion chaperone-like molecule that binds close to the C-terminal secretion signal of the CagA effector protein. Microbiology 153: 2896-2909 [Abstract] [Full Text]  
• Gunton, J. E., Gilmour, M. W., Baptista, K. P., Lawley, T. D., Taylor, D. E. (2007). Interaction between the co-inherited TraG coupling protein and the TraJ membrane-associated protein of the H-plasmid conjugative DNA transfer system resembles chromosomal DNA translocases. Microbiology 153: 428-441 [Abstract] [Full Text]  
• Bourzac, K. M., Satkamp, L. A., Guillemin, K. (2006). The Helicobacter pylori cag Pathogenicity Island Protein CagN Is a Bacterial Membrane-Associated Protein That Is Processed at Its C Terminus.. Infect. Immun. 74: 2537-2543 [Abstract] [Full Text]