Ankyrin-G palmitoylation and βII-spectrin binding to phosphoinositide lipids drive lateral membrane assembly

J Cell Biol. 2014 Jul 21;206(2):273-88. doi: 10.1083/jcb.201401016.

Abstract

Ankyrin-G and βII-spectrin colocalize at sites of cell-cell contact in columnar epithelial cells and promote lateral membrane assembly. This study identifies two critical inputs from lipids that together provide a rationale for how ankyrin-G and βII-spectrin selectively localize to Madin-Darby canine kidney (MDCK) cell lateral membranes. We identify aspartate-histidine-histidine-cysteine 5/8 (DHHC5/8) as ankyrin-G palmitoyltransferases required for ankyrin-G lateral membrane localization and for assembly of lateral membranes. We also find that βII-spectrin functions as a coincidence detector that requires recognition of both ankyrin-G and phosphoinositide lipids for its lateral membrane localization. DHHC5/8 and βII-spectrin colocalize with ankyrin-G in micrometer-scale subdomains within the lateral membrane that are likely sites for palmitoylation of ankyrin-G. Loss of either DHHC5/8 or ankyrin-G-βII-spectrin interaction or βII-spectrin-phosphoinositide recognition through its pleckstrin homology domain all result in failure to build the lateral membrane. In summary, we identify a functional network connecting palmitoyltransferases DHHC5/8 with ankyrin-G, ankyrin-G with βII-spectrin, and βII-spectrin with phosphoinositides that is required for the columnar morphology of MDCK epithelial cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Ankyrins / analysis
  • Ankyrins / metabolism*
  • Ankyrins / physiology
  • Cell Membrane / metabolism
  • Cell Polarity
  • Dogs
  • Epithelial Cells / metabolism
  • Epithelial Cells / ultrastructure
  • Gene Knockdown Techniques
  • Lipoylation
  • Membrane Proteins / analysis
  • Membrane Proteins / metabolism*
  • Membrane Proteins / physiology
  • Models, Biological
  • Phosphatidylinositols / metabolism*
  • Spectrin / analysis
  • Spectrin / metabolism*
  • Spectrin / physiology

Substances

  • Ankyrins
  • Membrane Proteins
  • Phosphatidylinositols
  • Spectrin