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ID 50623
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Author
Chattopadhyay, Santanu
Patra, Rajashree
Chatterjee, Raghunath
De, Ronita
Alam, Jawed
Ramamurthy, T.
Chowdhury, Abhijit
Nair, G. Balakrish
Berg, Douglas E.
Mukhopadhyay, Asish K.
Abstract
Background: Infection with Helicobacter pylori strains that express CagA is associated with gastritis, peptic ulcer disease, and gastric adenocarcinoma. The biological function of CagA depends on tyrosine phosphorylation by a cellular kinase. The phosphate acceptor tyrosine moiety is present within the EPIYA motif at the C-terminal region of the protein. This region is highly polymorphic due to variations in the number of EPIYA motifs and the polymorphism found in spacer regions among EPIYA motifs. The aim of this study was to analyze the polymorphism at the C-terminal end of CagA and to evaluate its association with the clinical status of the host in West Bengal, India. Results: Seventy-seven H. pylori strains isolated from patients with various clinical statuses were used to characterize the C-ternimal polymorphic region of CagA. Our analysis showed that there is no correlation between the previously described CagA types and various disease outcomes in Indian context. Further analyses of different CagA structures revealed that the repeat units in the spacer sequences within the EPIYA motifs are actually more discrete than the previously proposed models of CagA variants. Conclusion: Our analyses suggest that EPIYA motifs as well as the spacer sequence units are present as distinct insertions and deletions, which possibly have arisen from extensive recombination events. Moreover, we have identified several new CagA types, which could not be typed by the existing systems and therefore, we have proposed a new typing system. We hypothesize that a cagA gene encoding higher number EPIYA motifs may perhaps have arisen from cagA genes that encode lesser EPIYA motifs by acquisition of DNA segments through recombination events.
Keywords
Helicobacter pylori
CagA
Duodenal ulcer
Published Date
2012-05-25
Publication Title
Gut Pathogens
Volume
volume4
Publisher
BioMed Central Ltd.
ISSN
1757-4749
Content Type
Journal Article
Project
Collaborative Research of Okayama University for Infectious Diseases in India
Official Url
http://dx.doi.org/10.1186/1757-4749-4-4
language
English
Copyright Holders
© 2012 Chattopadhyay et al.; licensee BioMed Central Ltd.
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Refereed
True
DOI
Web of Science KeyUT