mda-9/Syntenin protein positively regulates the activation of Akt protein by facilitating integrin-linked kinase adaptor function during adhesion to type I collagen

J Biol Chem. 2011 Sep 23;286(38):33601-12. doi: 10.1074/jbc.M110.206789. Epub 2011 Aug 2.

Abstract

The integrin-linked kinase (ILK)-PINCH1-α-parvin (IPP) complex functions as a signaling platform for integrins that modulates various cellular processes. ILK functions as a central adaptor for the assembly of IPP complex. We report here that mda-9/syntenin, a positive regulator of cancer metastasis, regulates the activation of Akt (also known as protein kinase B) by facilitating ILK adaptor function during adhesion to type I collagen (COL-I) in human breast cancer cells. COL-I stimulation induced the phosphorylation and plasma membrane translocation of Akt. Inhibition of mda-9/syntenin or expression of mutant ILK (E359K) significantly blocked the translocation of both ILK and Akt to the plasma membrane. mda-9/syntenin associated with ILK, and this association was increased at the plasma membrane by COL-I stimulation. Knockdown of mda-9/syntenin impaired COL-I-induced association of ILK with Akt and plasma membrane targeting of ILK-Akt complex. These results demonstrated that mda-9/syntenin regulates the activation of Akt by controlling the plasma membrane targeting of Akt via a mechanism that facilitates the association of Akt with ILK at the plasma membrane during adhesion to COL-I. On a striking note, inhibition of mda-9/syntenin impaired COL-I-induced plasma membrane translocation of the IPP complex and assembly of integrin β1-IPP signaling complexes. Thus, our study defines the role of mda-9/syntenin in ILK adaptor function and describes a new mechanism of mda-9/syntenin for regulation of cell migration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Adhesiveness / drug effects
  • Cell Line, Tumor
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cell Movement / drug effects
  • Collagen Type I / pharmacology*
  • Enzyme Activation / drug effects
  • Humans
  • Integrin beta1 / metabolism
  • LIM Domain Proteins / metabolism
  • Membrane Proteins / metabolism
  • Microfilament Proteins / metabolism
  • Multiprotein Complexes / metabolism
  • Protein Binding / drug effects
  • Protein Serine-Threonine Kinases / metabolism*
  • Protein Transport / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction / drug effects
  • Syntenins / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Collagen Type I
  • Integrin beta1
  • LIM Domain Proteins
  • LIMS1 protein, human
  • Membrane Proteins
  • Microfilament Proteins
  • Multiprotein Complexes
  • PARVA protein, human
  • SDCBP protein, human
  • Syntenins
  • integrin-linked kinase
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt