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The Helicobacter pylori CagA protein induces tyrosine dephosphorylation of ezrin

Item Type:Article
Title:The Helicobacter pylori CagA protein induces tyrosine dephosphorylation of ezrin
Creators Name:Selbach, M. and Moese, S. and Backert, S. and Jungblut, P.R. and Meyer, T.F.
Abstract:Helicobacter pylori is one of the most wide-spread bacterial pathogens and infects the human stomach to cause diseases, such as gastritis, gastric ulceration, and gastric cancer. A major virulence determinant is the H. pylori CagA protein (encoded by the cytotoxin-associated gene A) which is translocated from the bacteria into the cytoplasm of host cells by a type IV secretion system. In the host cell, CagA is phosphorylated on tyrosine residues and induces rearrangements of the actin cytoskeleton. We have previously shown that tyrosine-phosphorylated CagA inhibits the catalytic activity of Src family kinases and induces tyrosine dephosphorylation of several host cell proteins. Here, we identified one of these proteins as ezrin by a combination of preparative gel electrophoresis, two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). Specific pharmacological inhibition of Src family kinases also induces ezrin dephosphorylation. Therefore, ezrin dephosphorylation appears to be induced by CagA-mediated Src inactivation. Ezrin is the founding member of the ezrin-radixin-moesin (ERM) family of proteins which are signalling integrators at the cell cortex. Since ezrin is a component of microvilli and a linker protein between actin filaments and membrane proteins, this observation has important implications for H. pylori pathogenesis and might also help to explain the development of gastric cancer.
Keywords:Actin cytoskeleton, Ezrin-radixin-moesin family, Molecular pathogenesis, Src, Type IV secretion
Page Range:2961-2968
Date:October 2004
Official Publication:https://doi.org/10.1002/pmic.200400915
PubMed:View item in PubMed

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