ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
Helicobacter pylori infection induces apoptosis in gastric epithelial cells. Here, we report a novel apoptosis-inducing protein that functions as a leading factor in H. pylori -mediated apoptosis induction. We purified the protein from H. pylori by separating fractions that showed apoptosis-inducing activity. This protein induced apoptosis of AGS cells in a dose-dependent manner. The purified protein consisted of two protein fragments with molecular masses of about 40 and 22 kDa, which combined to constitute a single complex in their natural form. N-terminal sequencing indicated that both these protein fragments were encoded by the HP1118 gene. The purified protein exhibited γ-glutamyl transpeptidase activity, the inhibition of which by 6-diazo-5-oxo- l -norleucine resulted in a complete loss of apoptosis-inducing activity. To the best of our knowledge, the apoptosis-inducing function is a newly identified physiological role for bacterial γ-glutamyl transpeptidase. The apoptosis-inducing activity of the isogenic mutant γ-glutamyl transpeptidase-deficient strain was significantly lower compared with that of the parent strain, demonstrating that γ-glutamyl transpeptidase plays a significant role in H. pylori -mediated apoptosis. Our findings provide new insights into H. pylori pathogenicity and reveal a novel aspect of the bacterial γ-glutamyl transpeptidase function.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-2958.2003.03305.x
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