Integrin-linked kinase complexes with caveolin-1 in human neuroblastoma cells

Biochemistry. 2005 Jan 25;44(3):932-8. doi: 10.1021/bi048619r.

Abstract

Integrin-linked kinase (ILK) and caveolin-1 (cav-1) are implicated in the pathogenesis of cancer. Overexpression of ILK leads to altered expression of cell cycle regulators, a decreased level of cell adhesion to the extracellular matrix, a decreased level of apoptosis, in vitro phosphorylation of Akt, and tumor formation in nude mice. Conversely, cav-1 expression is frequently downregulated in many forms of cancer. We examined whether ILK and cav-1 interact in SHEP human neuroblastoma cells because ILK is present in caveolae-enriched membranes and contains a putative cav-binding domain. SHEP cells were stably transfected with vector, wild-type ILK (ILK-wt), kinase-deficient ILK (ILK-kd), or mutant cav-binding domain ILK (ILK-mutCavbd). Control SHEP cells and ILK transfectants express high levels of ILK and cav-1. Immunoprecipitation with anti-cav-1 co-immunoprecipitates a 59 kDa protein that is immunoreactive with the anti-ILK antibody, and this interaction is partially prevented in cells expressing ILK-mutCavbd. Cav-1 and ILK partially colocalize in SHEP cells, also supporting these data. Last, affinity chromatography with a biotinylated cav-scaffolding domain peptide precipitates ILK-wt but not ILK-mutCavbd. These data suggest that the cav-binding domain of ILK and the cav-scaffolding domain of cav-1 mediate complex formation in human neuroblastoma cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Caveolin 1
  • Caveolins / metabolism*
  • Cell Line, Tumor
  • DNA Primers
  • Fluorescent Antibody Technique
  • Humans
  • Immunoprecipitation
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*

Substances

  • CAV1 protein, human
  • Caveolin 1
  • Caveolins
  • DNA Primers
  • integrin-linked kinase
  • Protein Serine-Threonine Kinases