Lysosomal targeting of E-cadherin: a unique mechanism for the down-regulation of cell-cell adhesion during epithelial to mesenchymal transitions

Mol Cell Biol. 2005 Jan;25(1):389-402. doi: 10.1128/MCB.25.1.389-402.2005.

Abstract

A hallmark characteristic of epithelial tumor progression as well as some processes of normal development is the loss of the epithelial phenotype and acquisition of a motile or mesenchymal phenotype. Such epithelial to mesenchymal transitions are accompanied by the loss of E-cadherin function by either transcriptional or posttranscriptional mechanisms. Here we demonstrate that, upon v-Src expression, a potent trigger of epithelial to mesenchymal transitions, E-cadherin is internalized and then shuttled to the lysosome instead of being recycled back to the lateral membrane. Thus, while E-cadherin internalization facilitates the dissolution of adherens junctions, its subsequent traffic to the lysosome serves as a means to ensure that cells do not reform their cell-cell contacts and remain motile. We also show that ubiquitin tagging of E-cadherin is essential for its sorting to the lysosome. The lysosomal targeting of E-cadherin is mediated by hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) and v-Src-induced activation of the Rab5 and Rab7 GTPases. Our studies reveal that the lysosomal targeting of E-cadherin is an important posttranscriptional mechanism to deplete cellular E-cadherin during Src-induced epithelial to mesenchymal transitions.

Publication types

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

MeSH terms

  • Animals
  • Biological Transport
  • Cadherins / metabolism*
  • Cell Adhesion
  • Cell Communication
  • Cell Line
  • Cell Movement
  • Cells, Cultured
  • Dogs
  • Down-Regulation*
  • Endosomal Sorting Complexes Required for Transport
  • Endosomes / metabolism
  • Enzyme Activation
  • Epithelial Cells / metabolism*
  • Immunoprecipitation
  • Lysosomes / metabolism*
  • Mesoderm / metabolism*
  • Microscopy, Fluorescence
  • Models, Biological
  • Phenotype
  • Phosphoproteins / metabolism
  • Plasmids / metabolism
  • RNA Processing, Post-Transcriptional
  • Retroviridae / genetics
  • Temperature
  • Time Factors
  • Transfection
  • Ubiquitin / metabolism
  • rab GTP-Binding Proteins / metabolism
  • rab5 GTP-Binding Proteins / metabolism
  • rab7 GTP-Binding Proteins
  • src-Family Kinases / metabolism

Substances

  • Cadherins
  • Endosomal Sorting Complexes Required for Transport
  • Phosphoproteins
  • Ubiquitin
  • hepatocyte growth factor-regulated tyrosine kinase substrate
  • rab7 GTP-Binding Proteins
  • src-Family Kinases
  • rab GTP-Binding Proteins
  • rab5 GTP-Binding Proteins