Helicobacter pylori chaperone-like protein CagT plays an essential role in the translocation of CagA into host cells.
Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAI) have been associated with more severe gastric disease in infected humans. The cag PAI is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cag PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cag PAI apparatus assembly.
Department of Clinical Microbiology and Immunology, Faculty of Medical Laboratory Science, Third Military Medical University and National Engineering Technological Research Center of Immunological Biologicals, Chongqing 400038, PR China. hongleiding@163.com
Honglei
H
Ding
Hao
H
Zeng
Linping
L
Huang
Yandong
Y
Dong
Yijun
Y
Duan
Xuhu
X
Mao
Gang
G
Guo
Quanming
Q
Zou
D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D018988:Bacterial Translocation; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D004848:Epithelium / Q000382:microbiology*; D044404:Genomic Islands; D016481:Helicobacter Infections / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D047468:Immunoprecipitation; D016209:Interleukin-8 / Q000378:metabolism; D018832:Molecular Chaperones / Q000378:metabolism; D010766:Phosphorylation; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D025941:Protein Interaction Mapping; D021381:Protein Transport; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; C508606:CXCL8 protein, human; D016209:Interleukin-8; D018832:Molecular Chaperones; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori