1. ¹Junior Research Group, Paul-Ehrlich Institute, Langen, Germany
2. ²Cancer Research UK, Weatherall Institute of Molecular Medicine, Oxford, UK

Correspondence: Dr S Wessler, Paul-Ehrlich-Institut, Paul-Ehrlich Strasse 51-59, D-63225 Langen, Hessen, Germany. E-mail: wessi@pei.de

Received 26 January 2006; Revised 8 September 2006; Accepted 19 October 2006; Published online 11 December 2006.

Abstract

Helicobacter pylori induces a strong motogenic response in infected gastric epithelial host cells, which is enhanced by translocation of the pathogenic factor cytotoxin-associated gene A (CagA) into host cells via a specialized type IV secretion system. Once injected into the cytosol CagA is rapidly tyrosine phosphorylated by Src family kinases followed by Src inactivation. Hence, it remained unknown why CagA is constantly phosphorylated in sustained H. pylori infections to induce cell migration, whereas other substrates of Src kinases are dephosphorylated. Here, we identify the non-receptor tyrosine kinase c-Abl as a crucial mediator of H. pylori-induced migration and novel CagA kinase in epithelial cells. Upon H. pylori infection c-Abl directly interacts with CagA and localizes in focal adhesion complexes and membrane ruffles, which are highly dynamic cytoskeletal structures necessary for cell motility. Selective inhibition of c-Abl kinase activity by STI571 or shRNA abrogates sustained CagA phosphorylation and epithelial cell migration, indicating a pivotal role of c-Abl in H. pylori infection and pathogenicity. These results implicate c-Abl as a novel molecular target for therapeutic intervention in H. pylori-related gastric diseases.