title: [H. pylori oncoprotein CagA and gastric cancer].
abstract: Helicobacter pylori CagA is the first identified bacterial oncoprotein playing a critical role in gastric carcinogenesis. Upon delivery into gastric epithelial cells via type IV secretion, CagA is localized to the plasma membrane, where it acts as a pathogenic scaffold/hub that promiscuously interacts with a number of host signaling molecules. Especially, CagA binds to the polarity-regulating kinase PAR1/MARK and inhibits the kinase activity. Following tyrosine phosphorylation by host kinases, CagA also acquires the ability to interact with the oncogenic tyrosine phosphatase SHP2 and deregulates the phosphatase activity. Through these interactions, CagA deregulates intracellular signaling pathways involved in cell proliferation and cell movement, while causing epithelial junctional and polarity defects. These CagA activities collectively contribute to the development of gastric carcinoma.
authors.affiliation: Division of Microbiology, Graduate School of Medicine, University of Tokyo.
authors.forename: Masanori
authors.initials: M
authors.lastname: Hatakeyama
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis / Q000502:physiology*; D001426:Bacterial Proteins / Q000032:analysis / Q000502:physiology*; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori / Q000737:chemistry; D006801:Humans; D013274:Stomach Neoplasms / Q000209:etiology*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori