title: Simple method for determination of the number of Helicobacter pylori CagA variable-region EPIYA tyrosine phosphorylation motifs by PCR.
abstract: Helicobacter pylori strains possessing the cag pathogenicity island are associated with the development of gastric cancer. The CagA protein is translocated into epithelial cells and becomes phosphorylated on tyrosine residues within EPIYA motifs, which may be repeated within the variable region of the protein. Strains possessing CagA with greater numbers of these repeats have been more closely associated with gastric carcinogenesis. Phosphorylated CagA leads to epithelial cell elongation, which is dependent on the number of variable-region EPIYA motifs. Thus, determination of the degree of CagA phosphorylation and the number of EPIYA motifs appears to be more important than detection of cagA alone. Determination of the number of EPIYA motifs by nucleotide sequencing, however, is a laborious and expensive process. We describe here a novel and rapid PCR method for determination of the pattern of repeats containing the EPIYA motif. This will aid in the identification of those strains that may be more likely to cause disease.
authors.affiliation: Institute of Infection, Immunity, and Inflammation, C Floor West Block, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK. richard.argent@nottingham.ac.uk
authors.forename: Richard H
authors.initials: RH
authors.lastname: Argent
authors.forename: Youli
authors.initials: Y
authors.lastname: Zhang
authors.forename: John C
authors.initials: JC
authors.lastname: Atherton
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000737:chemistry* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D014644:Genetic Variation; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D016133:Polymerase Chain Reaction / Q000379:methods*; D012091:Repetitive Sequences, Nucleic Acid; D014443:Tyrosine
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori; D014443:Tyrosine