VCP phosphorylation-dependent interaction partners prevent apoptosis in Helicobacter pylori-infected gastric epithelial cells

PLoS One. 2013;8(1):e55724. doi: 10.1371/journal.pone.0055724. Epub 2013 Jan 31.

Abstract

Previous studies have demonstrated that valosin-containing protein (VCP) is associated with H. pylori-induced gastric carcinogenesis. By identifying the interactome of VCP overexpressed in AGS cells using a subtractive proteomics approach, we aimed to characterize the cellular responses mediated by VCP and its functional roles in H. pylori-associated gastric cancer. VCP immunoprecipitations followed by proteomic analysis identified 288 putative interacting proteins, 18 VCP-binding proteins belonged to the PI3K/Akt signaling pathway. H. pylori infection increased the interaction between Akt and VCP, Akt-dependent phosphorylation of VCP, levels of ubiquitinated proteins, and aggresome formation in AGS cells. Furthermore, phosphorylated VCP co-localized with the aggresome, bound ubiquitinated proteins, and increased the degradation of cellular regulators to protect H. pylori-infected AGS cells from apoptosis. Our study demonstrates that VCP phosphorylation following H. pylori infection promotes both gastric epithelial cell survival, mediated by the PI3K/Akt pathway, and the degradation of cellular regulators. These findings provide novel insights into the mechanisms of H. pylori infection induced gastric carcinogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Animals
  • Apoptosis*
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / metabolism*
  • Cell Line, Tumor
  • Cell Survival
  • Epithelial Cells / metabolism*
  • Epithelial Cells / microbiology
  • Gastric Mucosa / metabolism*
  • Gastric Mucosa / microbiology
  • Helicobacter Infections / metabolism*
  • Helicobacter pylori*
  • Humans
  • Male
  • Mice
  • Multiprotein Complexes / metabolism
  • Phosphorylation
  • Protein Binding
  • Protein Interaction Mapping
  • Protein Interaction Maps
  • Proteolysis
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction
  • Ubiquitinated Proteins / metabolism
  • Valosin Containing Protein

Substances

  • Carrier Proteins
  • Cell Cycle Proteins
  • Multiprotein Complexes
  • Ubiquitinated Proteins
  • Proto-Oncogene Proteins c-akt
  • Adenosine Triphosphatases
  • VCP protein, human
  • Valosin Containing Protein
  • Vcp protein, mouse

Grants and funding

This work was supported in part by the Program for Excellence Research Teams of the Ministry of Education, Grant 98-2320-B-002-030-MY3 from the National Science Council, and Liver Disease Prevention & Treatment Research Foundation, Taiwan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.