The E-cadherin complex contains the src substrate p120

Exp Cell Res. 1995 May;218(1):359-69. doi: 10.1006/excr.1995.1167.


Using normal MDCK cells, and MDCK cells stably transfected with a temperature-sensitive viral src allele (pp60 ts-v-src), we have examined the composition and tyrosine phosphorylation of the E-cadherin complex. E-cadherin is a transmembrane calcium-dependent cell-cell adhesion molecule that is complexed with cytoplasmic proteins including alpha-catenin, beta-catenin, plakoglobin (gamma-catenin), and actin. We have identified two heterodimeric complexes which demonstrate that alpha-catenin interacts directly with beta-catenin, or with plakoglobin, in the absence of E-cadherin. beta-Catenin has previously been shown to bind directly to E-cadherin. We propose that E-cadherin associates with alpha-catenin, and thereby the actin cytoskeleton, via either beta-catenin or plakoglobin. We have further identified three new but related protein components of the E-cadherin complex, which are each cross-reactive by Western blot analysis to antibodies directed against p120, a phosphotyrosine substrate of src, and a phosphotyrosine, phosphoserine, and phosphothreonine substrate of growth factor-stimulated signaling pathways. Greater quantities of the p120-related proteins were found present in the E-cadherin immunoprecipitates of ts-src MDCK cells compared to normal MDCK cells, while two of the p120 cross-reactive species were significantly tyrosine phosphorylated in both normal and ts-src MDCK cells. The association of p120-related species with the E-cadherin complex adds them to our consideration of possible modulators of cadherin function. Likewise, the newly identified alpha-catenin-beta-catenin and alpha-catenin-plakoglobin dimers may have interesting biological properties, conceivably including the titration of catenins between cadherin and APC complexes.

Publication types

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

MeSH terms

  • Animals
  • Antibodies
  • Cadherins / chemistry*
  • Cadherins / isolation & purification
  • Cadherins / metabolism*
  • Cell Line
  • Concanavalin A
  • Cytoskeletal Proteins / isolation & purification
  • Cytoskeletal Proteins / metabolism
  • Dogs
  • Electrophoresis, Polyacrylamide Gel
  • Genes, src*
  • Genetic Vectors
  • Kidney
  • Methionine / metabolism
  • Oncogene Protein pp60(v-src) / isolation & purification
  • Oncogene Protein pp60(v-src) / metabolism*
  • Phosphorylation
  • Phosphotyrosine
  • Retroviridae
  • Trans-Activators*
  • Transfection
  • Tyrosine / analogs & derivatives
  • Tyrosine / analysis
  • alpha Catenin
  • beta Catenin


  • Antibodies
  • Cadherins
  • Cytoskeletal Proteins
  • Trans-Activators
  • alpha Catenin
  • beta Catenin
  • Concanavalin A
  • Phosphotyrosine
  • Tyrosine
  • Methionine
  • Oncogene Protein pp60(v-src)