title: Fragmentation of CagA Reduces Hummingbird Phenotype Induction by Helicobactor pylori.
abstract: Infection with Helicobacter pylori (H. pylori) has been linked to various gastro-intestinal diseases; nevertheless it remains to be clarified why only a minority of infected individuals develop illness. Studies from the West have indicated that the cagA gene and the associated EPIYA genotype of H. pylori is closely linked to the development of severe gastritis and gastric carcinoma; however, as yet no consistent correlation has been found among the bacteria from East Asia. In addition to genotype variation, the CagA protein undergoes fragmentation; however, the functional significance of fragmentation with respect to H. pylori infection remains unknown. In this study, we isolated 594 H. pylori colonies from 99 patients and examined the fragmentation patterns of CagA protein using immunoblotting. By analyzing the ability of the isolates to induce the host cell morphological transition to the highly invasive hummingbird phenotype, we demonstrated that H. pylori colonies with substantial CagA fragmentation are less potent in terms of causing this morphological transition. Our results uncovered a functional role for CagA fragmentation with respect to H. pylori-induced hummingbird phenotype formation and these findings suggest the possibility that the post-translational processing of CagA may be involved in H. pylori infection pathogenesis.
authors.affiliation: Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chih-Chi
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Intensive Care Unit, Cheng-Hsin General Hospital, Taipei, Taiwan.
authors.forename: Wein-Shung
authors.initials: WS
authors.lastname: Kuo
authors.affiliation: Division of Digestive Medicine, Taipei City Hospital Yangming Branch, Taipei, Taiwan.
authors.forename: Ying-Chieh
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Division of Gastroenterology, Department of Medicine, VGH-Taipei, Taiwan, and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chin-Lin
authors.initials: CL
authors.lastname: Perng
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Taipei Medical University, Shuang-Ho Hospital, New Taipei City, Taiwan, and Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Hwai-Jeng
authors.initials: HJ
authors.lastname: Lin
authors.affiliation: Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yueh-Hsing
authors.initials: YH
authors.lastname: Ou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D053938:DNA Fragmentation; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology; D005756:Gastritis / Q000382:microbiology; D005838:Genotype; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011499:Protein Processing, Post-Translational / Q000235:genetics; D013274:Stomach Neoplasms / Q000382:microbiology; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori