title: Genes required for assembly of pili associated with the Helicobacter pylori cag type IV secretion system.
abstract: Helicobacter pylori causes numerous alterations in gastric epithelial cells through processes that are dependent on activity of the cag type IV secretion system (T4SS). Filamentous structures termed "pili" have been visualized at the interface between H. pylori and gastric epithelial cells, and previous studies suggested that pilus formation is dependent on the presence of the cag pathogenicity island (PAI). Thus far, there has been relatively little effort to identify specific genes that are required for pilus formation, and the role of pili in T4SS function is unclear. In this study, we selected 7 genes in the cag PAI that are known to be required for T4SS function and investigated whether these genes were required for pilus formation. cagT, cagX, cagV, cagM, and cag3 mutants were defective in both T4SS function and pilus formation; complemented mutants regained T4SS function and the capacity for pilus formation. cagY and cagC mutants were defective in T4SS function but retained the capacity for pilus formation. These results define a set of cag PAI genes that are required for both pilus biogenesis and T4SS function and reveal that these processes can be uncoupled in specific mutant strains.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Johnson
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Gaddy
authors.affiliation: Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Voss
authors.affiliation: Department of Gastroenterology and Hepatology, Medical Center for Postgraduate Education, Warsaw, Poland Department of Genetics, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland.
authors.forename: Ewa E
authors.initials: EE
authors.lastname: Hennig
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee, USA timothy.l.cover@vanderbilt.edu.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Cover
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D002460:Cell Line; D004847:Epithelial Cells / Q000382:microbiology; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism*; D055786:Gene Knockout Techniques; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D044404:Genomic Islands; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D055503:Protein Multimerization
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D046912:Multiprotein Complexes