The Na-K-ATPase α₁β₁ heterodimer as a cell adhesion molecule in epithelia

Am J Physiol Cell Physiol. 2012 May 1;302(9):C1271-81. doi: 10.1152/ajpcell.00456.2011. Epub 2012 Jan 25.

Abstract

The ion gradients generated by the Na-K-ATPase play a critical role in epithelia by driving transepithelial transport of various solutes. The efficiency of this Na-K-ATPase-driven vectorial transport depends on the integrity of epithelial junctions that maintain polar distribution of membrane transporters, including the basolateral sodium pump, and restrict paracellular diffusion of solutes. The review summarizes the data showing that, in addition to pumping ions, the Na-K-ATPase located at the sites of cell-cell junction acts as a cell adhesion molecule by interacting with the Na-K-ATPase of the adjacent cell in the intercellular space accompanied by anchoring to the cytoskeleton in the cytoplasm. The review also discusses the experimental evidence on the importance of a specific amino acid region in the extracellular domain of the Na-K-ATPase β(1) subunit for the Na-K-ATPase trans-dimerization and intercellular adhesion. Furthermore, a possible role of N-glycans linked to the Na-K-ATPase β(1) subunit in regulation of epithelial junctions by modulating β(1)-β(1) interactions is discussed.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cell Adhesion Molecules / chemistry
  • Cell Adhesion Molecules / metabolism*
  • Epithelial Cells / chemistry
  • Epithelial Cells / metabolism*
  • Humans
  • Intercellular Junctions / chemistry
  • Intercellular Junctions / metabolism
  • Protein Multimerization*
  • Protein Structure, Quaternary
  • Sodium-Potassium-Exchanging ATPase / chemistry
  • Sodium-Potassium-Exchanging ATPase / metabolism*

Substances

  • Cell Adhesion Molecules
  • Sodium-Potassium-Exchanging ATPase