Interaction with CagF is required for translocation of CagA into the host via the Helicobacter pylori type IV secretion system.

Full Abstract

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.

Author information

Author/s: Couturier, Marc Roger (MR); Tasca, Elizabetta (E); Montecucco, Cesare (C); Stein, Markus (M);

Affiliation: Department of Medical Microbiology and Immunology, University of Alberta, 1-17 Medical Sciences Building, Edmonton, Alberta T6G 2R3, Canada.

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Infection and immunity (Infect Immun), published in United States. (Language: eng)

Reference: 2006-Jan; vol 74 (issue 1) : pp 273-81

Dates: Created 2005/12/21; Completed 2006/02/07; Revised 2008/11/20;

PMID: 16368981, status: MEDLINE (last retrieved date: 2/18/2009)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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MeSH headings (categories)

This article was linked to the MeSH Headings (categories) shown below.

Antigens, Bacterial - genetics; metabolism; physiology
Bacterial Proteins - genetics; metabolism; physiology; secretion
Cell Line
Gastric Mucosa - microbiology

Helicobacter Infections - microbiology
Helicobacter pylori - immunology; pathogenicity; physiology
Humans
Protein Transport - immunology

Note: Bold headings indicate primary MeSH headings or qualifiers.

Associated Chemicals: Antigens, Bacterial (0) ; Bacterial Proteins (0) ; cagA protein, Helicobacter pylori (0) ; cagF protein, Helicobacter pylori (0)

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