Ankyrin-G is a molecular partner of E-cadherin in epithelial cells and early embryos

J Biol Chem. 2007 Sep 7;282(36):26552-61. doi: 10.1074/jbc.M703158200. Epub 2007 Jul 9.

Abstract

E-cadherin is a ubiquitous component of lateral membranes in epithelial tissues and is required to form the first lateral membrane domains in development. Here, we identify ankyrin-G as a molecular partner of E-cadherin and demonstrate that ankyrin-G and beta-2-spectrin are required for accumulation of E-cadherin at the lateral membrane in both epithelial cells and early embryos. Ankyrin-G binds to the cytoplasmic domain of E-cadherin at a conserved site distinct from that of beta-catenin. Ankyrin-G also recruits beta-2-spectrin to E-cadherin-beta-catenin complexes, thus providing a direct connection between E-cadherin and the spectrin/actin skeleton. In addition to restricting the membrane mobility of E-cadherin, ankyrin-G and beta-2-spectrin also are required for exit of E-cadherin from the trans-Golgi network in a microtubule-dependent pathway. Ankyrin-G and beta-2-spectrin co-localize with E-cadherin in preimplantation mouse embryos. Moreover, knockdown of either ankyrin-G or beta-2-spectrin in one cell of a two-cell embryo blocks accumulation of E-cadherin at sites of cell-cell contact. E-cadherin thus requires both ankyrin-G and beta-2-spectrin for its cellular localization in early embryos as well as cultured epithelial cells. We have recently reported that ankyrin-G and beta-2-spectrin collaborate in biogenesis of the lateral membrane ( Kizhatil, K., Yoon, W., Mohler, P. J., Davis, L. H., Hoffman, J. A., and Bennett, V. (2007) J. Biol. Chem. 282, 2029-2037 ). Together with the current findings, these data suggest a ankyrin/spectrin-based mechanism for coordinating membrane assembly with extracellular interactions of E-cadherin at sites of cell-cell contact.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Ankyrins / deficiency
  • Ankyrins / metabolism*
  • Blastomeres / cytology
  • Blastomeres / metabolism*
  • Cadherins / metabolism*
  • Carrier Proteins / metabolism
  • Cell Line
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism*
  • Humans
  • Intercellular Junctions / genetics
  • Intercellular Junctions / metabolism*
  • Mice
  • Microfilament Proteins / deficiency
  • Microfilament Proteins / metabolism
  • Microtubules / metabolism
  • Protein Binding / physiology
  • Protein Structure, Tertiary / physiology
  • Protein Transport / physiology
  • beta Catenin / metabolism*
  • trans-Golgi Network / genetics
  • trans-Golgi Network / metabolism*

Substances

  • Actins
  • Ank3 protein, mouse
  • Ankyrins
  • Cadherins
  • Carrier Proteins
  • Microfilament Proteins
  • beta Catenin
  • fodrin