Cell binding function of E-cadherin is regulated by the cytoplasmic domain

EMBO J. 1988 Dec 1;7(12):3679-84.

Abstract

Cadherins are a family of transmembrane glycoproteins responsible for Ca2+-dependent cell-cell adhesion. Their amino acid sequences are highly conserved in the cytoplasmic domain. To study the role of the cytoplasmic domain in the function of cadherins, we constructed expression vectors with cDNAs encoding the deletion mutants of E-cadherin polypeptides, in which the carboxy terminus was truncated at various lengths. These vectors were introduced into L cells by transfection, and cell lines expressing the mutant E-cadherin molecules were isolated. In all transfectants obtained, the extracellular domain of the mutant E-cadherins was exposed on the cell surface, and had normal Ca2+-sensitivity and molecular size. However, these cells did not show any Ca2+-dependent aggregation, indicating that the mutant molecules cannot mediate cell-cell binding. The mutant E-cadherin molecules could be released from cells by nonionic detergents, whereas a fraction of normal E-cadherin molecules could not be extracted with the detergent and appeared to be anchored to the cytoskeleton at cell-cell junctions. These results suggest that the cytoplasmic domain regulates the cell-cell binding function of the extracellular domain of E-cadherin, possibly through interaction with some cytoskeletal components.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Surface / physiology*
  • Blotting, Western
  • Calcium / pharmacology
  • Cell Adhesion Molecules
  • Cell Adhesion*
  • DNA Mutational Analysis
  • Fluorescent Antibody Technique
  • L Cells
  • Membrane Glycoproteins / physiology*
  • Membrane Glycoproteins / ultrastructure
  • Structure-Activity Relationship
  • Transfection

Substances

  • Antigens, Surface
  • Cell Adhesion Molecules
  • Membrane Glycoproteins
  • Calcium