Functional molecular imaging of ILK-mediated Akt/PKB signaling cascades and the associated role of beta-parvin

J Cell Sci. 2010 Mar 1;123(Pt 5):747-55. doi: 10.1242/jcs.052498.

Abstract

Visualization and quantification of the dynamics of protein-protein interactions in living cells can be used to explore the macromolecular events involved in signal transduction processes. In this study, functional molecular imaging using a luciferase-based complementation method demonstrated how the integrin-linked kinase (ILK)-mediated protein complex controls downstream signals. The luciferase complementation assay showed that Akt1 preferentially binds to beta-parvin rather than to ILK within the complex. Moreover, photon flux from the interaction between beta-parvin and Akt1 increased following serum stimulation, and the beta-parvin-Akt1 interaction was dependent on phosphoinositide 3-kinase. Intriguingly, small interfering (si)RNA-mediated beta-parvin knockdown increased photon flux from the interaction between ILK and Akt1, leading to stabilization of hypoxia-inducible factor-1alpha and increased expression of vascular endothelial growth factor-A. These data from functional molecular imaging demonstrated that beta-parvin plays a regulatory role in the ILK-mediated Akt (also called protein kinase B) signaling cascades, suggesting that beta-parvin might be a crucial modulator of cell survival.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinin / genetics
  • Actinin / metabolism*
  • Animals
  • Blotting, Western
  • Cell Line
  • Cell Survival / genetics
  • Cell Survival / physiology
  • Humans
  • Hypoxia-Inducible Factor 1 / metabolism
  • Immunoprecipitation
  • Mice
  • NIH 3T3 Cells
  • Phosphatidylinositol 3-Kinases / metabolism
  • Protein Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Hypoxia-Inducible Factor 1
  • PARVB protein, human
  • Parvb protein, mouse
  • Vascular Endothelial Growth Factor A
  • Actinin
  • integrin-linked kinase
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt