title: Composition, structure and function of the Helicobacter pylori cag pathogenicity island encoded type IV secretion system.
abstract: Many Gram-negative pathogens harbor type IV secretion systems (T4SS) that translocate bacterial virulence factors into host cells to hijack cellular processes. The pathology of the gastric pathogen Helicobacter pylori strongly depends on a T4SS encoded by the cag pathogenicity island. This T4SS forms a needle-like pilus, and its assembly is accomplished by multiple protein-protein interactions and various pilus-associated factors that bind to integrins followed by delivery of the CagA oncoprotein into gastric epithelial cells. Recent studies revealed the crystal structures of six T4SS proteins and pilus formation is modulated by iron and zinc availability. All these T4SS interactions are crucial for deregulating host signaling events and disease progression. New developments in T4SS functions and their importance for pathogenesis are discussed.
authors.affiliation: Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Backert
authors.affiliation: Department of Biology, Division of Microbiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstr. 5, D-91058 Erlangen, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Tegtmeyer
authors.affiliation: Max von Pettenkofer-Institute for Hygiene & Medical Microbiology, Ludwig Maximilians-University, D-80336 Munich, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Fischer
mesh_terms: D000942:Antigens, Bacterial / Q000378:metabolism; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism; D004847:Epithelial Cells / Q000382:microbiology / Q000502:physiology; D044404:Genomic Islands; D016480:Helicobacter pylori / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D011487:Protein Conformation; D055503:Protein Multimerization; D021381:Protein Transport; D000069319:Type IV Secretion Systems / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D000069319:Type IV Secretion Systems; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori
keywords: CagA; CagL; CagY; EGF receptor; GTPase; Helicobacter pylori; MARK2/PAR1b kinase; T4SS; VirB proteins; c-Met; cagPAI; cortactin; gastric disease; integrin; signaling; type IV secretion; tyrosine kinases; β-catenin