Phosphorylation of Helicobacter pylori CagA by c-Abl leads to cell motility

Oncogene. 2007 May 24;26(24):3462-72. doi: 10.1038/sj.onc.1210139. Epub 2006 Dec 11.

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.

MeSH terms

  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / metabolism*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Benzamides
  • Cell Adhesion
  • Cell Line, Tumor
  • Cell Movement*
  • Epithelial Cells / pathology
  • Helicobacter Infections / metabolism*
  • Helicobacter Infections / pathology*
  • Helicobacter pylori / pathogenicity
  • Humans
  • Imatinib Mesylate
  • Phosphorylation
  • Piperazines / pharmacology
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-abl / antagonists & inhibitors
  • Proto-Oncogene Proteins c-abl / genetics
  • Proto-Oncogene Proteins c-abl / metabolism*
  • Pyrimidines / pharmacology

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • Benzamides
  • Piperazines
  • Protein Kinase Inhibitors
  • Pyrimidines
  • cagA protein, Helicobacter pylori
  • Imatinib Mesylate
  • Proto-Oncogene Proteins c-abl