Oligomerization and phosphorylation dependent regulation of ArgBP2 adaptive capabilities and associated functions

PLoS One. 2014 Jan 27;9(1):e87130. doi: 10.1371/journal.pone.0087130. eCollection 2014.

Abstract

ArgBP2 (Arg-Binding Protein 2/SORBS2) is an adaptor protein involved in cytoskeleton associated signal transduction, thereby regulating cell migration and adhesion. These features are associated with its antitumoral role in pancreatic cancer cells. Tyrosine phosphorylation of ArgBP2, mediated by c-Abl kinase and counterbalanced by PTP-PEST phosphatase, regulates many of its interactions. However, the exact mechanisms of action and of regulation of ArgBP2 remain largely unknown. We found that ArgBP2 has the capacity to form oligomers which are destabilized by tyrosine phosphorylation. We could show that ArgBP2 oligomerization involves the binding of one of its SH3 domains to a specific proline rich cluster. ArgBP2 self-association increases its binding to some of its molecular partners and decreased its affinity for others. Hence, the phosphorylation/oligomerization state of ArgBP2 directly regulates its functions by modulating its adaptive capabilities. Importantly, using a human pancreatic cancer cell model (MiaPaCa-2 cells), we could validate that this property of ArgBP2 is critical for its cytoskeleton associated functions. In conclusions, we describe a new mechanism of regulation of ArgBP2 where tyrosine phosphorylation of the protein interfere with a SH3 mediated self-interaction, thereby controlling its panel of interacting partners and related functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / physiology*
  • Adaptor Proteins, Signal Transducing
  • Bioluminescence Resonance Energy Transfer Techniques
  • Blotting, Far-Western
  • Blotting, Western
  • Cell Line, Tumor
  • Cytoskeletal Proteins / metabolism*
  • DNA Primers / genetics
  • Fluorescent Antibody Technique
  • HEK293 Cells
  • Homeodomain Proteins / metabolism*
  • Humans
  • Immunoprecipitation
  • Phosphorylation
  • Polymerization
  • RNA-Binding Proteins
  • Tyrosine

Substances

  • Adaptor Proteins, Signal Transducing
  • Cytoskeletal Proteins
  • DNA Primers
  • Homeodomain Proteins
  • RNA-Binding Proteins
  • SORBS2 protein, human
  • Tyrosine

Grants and funding

This work was supported by a FRM (Fondation pour la recherche médicale)/Institut Lilly fellowship to J.R., and T.B. was a fellow of La Ligue contre le cancer. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.