title: Growth phase-dependent composition of the Helicobacter pylori exoproteome.
abstract: Helicobacter pylori colonizes the human stomach and is associated with an increased risk of gastric cancer and peptic ulcer disease. Analysis of H. pylori protein secretion is complicated by the occurrence of bacterial autolysis. In this study, we analyzed the exoproteome of H. pylori at multiple phases of bacterial growth and identified 74 proteins that are selectively released into the extracellular space. These include proteins known to cause alterations in host cells, antigenic proteins, and additional proteins that have not yet been studied in any detail. The composition of the H. pylori exoproteome is dependent on the phase of bacterial growth. For example, the proportional abundance of the vacuolating toxin VacA in culture supernatant is higher during late growth phases than early growth phases, whereas the proportional abundance of many other proteins is higher during early growth phases. We detected marked variation in the subcellular localization of putative secreted proteins within soluble and membrane fractions derived from intact bacteria. By providing a comprehensive view of the H. pylori exoproteome, these results provide new insights into the array of secreted H. pylori proteins that may cause alterations in the gastric environment.
authors.affiliation: Department of Medicine, Nashville, TN, USA.
authors.forename: Christina A
authors.initials: CA
authors.lastname: Snider
authors.affiliation: Department of Pathology, Microbiology and Immunology, Nashville, TN, USA.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Voss
authors.affiliation: Proteomics Laboratory, Mass Spectrometry Research Center, Nashville, TN, USA; Department of Biochemistry, Nashville, TN, USA.
authors.forename: W Hayes
authors.initials: WH
authors.lastname: McDonald
authors.affiliation: Department of Medicine, Nashville, TN, USA; Department of Pathology, Microbiology and Immunology, Nashville, TN, USA; Vanderbilt University School of Medicine, Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, USA. Electronic address: timothy.l.cover@vanderbilt.edu.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Cover
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D016000:Cluster Analysis; D005756:Gastritis / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry; D021382:Protein Sorting Signals; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D012995:Solubility; D013270:Stomach / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D021382:Protein Sorting Signals; D020543:Proteome; C074689:VacA protein, Helicobacter pylori
keywords: Autolysis; Autotransporter; Bacterial protein secretion; Exoproteome; Gastric cancer; Mass spectrometry; Outer membrane vesicles; Peptic ulcer disease; Proteomics; Secretome; VacA