Colonization of the human stomach with Helicobacter pylori strains containing the cag pathogenicity island is a risk factor for development of gastric cancer. The cag pathogenicity island contains genes encoding a secreted effector protein (CagA) and components of a type IV secretion system (Cag T4SS). The molecular architecture of the H. pylori Cag T4SS is substantially more complex than that of prototype T4SSs in other bacterial species. In this review, we discuss recent discoveries pertaining to the structure and function of the Cag T4SS and its role in gastric cancer pathogenesis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7363556 | PMC |
http://dx.doi.org/10.1016/j.tim.2020.02.004 | DOI Listing |
Gut Microbes
November 2024
Department of Medicine, Division of Infectious Disease, Vanderbilt University School of Medicine, Nashville, TN, USA.
infection is the predominant risk factor for the development of gastric cancer. Risk is enhanced by specific virulence factors, diet, and the inflammatory response. Chronic activation of T helper (Th) 1 and Th17 pathways contributes to prolonged inflammation; yet, higher expression of IL-17 receptor (IL-17RA) is a favorable prognostic marker for survival after gastric cancer diagnosis.
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December 2024
Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, People's Republic of China.
The () cytotoxin-associated gene pathogenicity island (PAI) encodes 31 genes that assemble the type IV secretion system (T4SS) apparatus, which includes structures such as the outer membrane core complex, periplasmic ring, inner membrane complex and bacterial hairs. These proteins interact with each other to inject CagA into the host gastric epithelium. There are also individual unique functions that help interfere with host cellular pathways, modulate the immune response and colonize the host for a long time.
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October 2024
Center for Protein Science and Crystallography, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China. Electronic address:
Cag type IV secretion system (CagT4SS) translocates oncoprotein cytotoxin-associated gene A (CagA) into host cells and plays a key role in the pathogenesis of Helicobacter pylori. The structure of the outer membrane core complex (OMCC) in CagT4SS consists of CagX, CagY, CagM, CagT, and Cag3 in a stoichiometric ratio of 1:1:2:2:5 with 14-fold symmetry. However, the assembly pathway of OMCC remains elusive.
View Article and Find Full Text PDFLife Sci Alliance
August 2024
Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
Life Sci Alliance
June 2024
Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
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