MAGI-1 interacts with beta-catenin and is associated with cell-cell adhesion structures

Biochem Biophys Res Commun. 2000 Apr 21;270(3):903-9. doi: 10.1006/bbrc.2000.2471.


The family of membrane-associated guanylate kinases (MAGUK) comprises peripheral membrane proteins involved in the formation of specialized cell-cell junctions. MAGUK proteins possess a conserved domain composition, containing PDZ, guanylate kinase, and SH3 or WW domains. MAGI-1 is a recently identified member of the MAGUK protein family. Three splice variantsof MAGI-1 have been characterized to date, including MAGI-1a, -1b, and -1c. MAGI-1b is predominantly associated with the crude membrane fraction. Here we show that the fifth PDZ domain of MAGI-1b is essential for membrane localization. We have also identified beta-catenin as a potential ligand for this PDZ domain. MAGI-1b forms complexes with beta-catenin and E-cadherin during the formation of cell-cell junctions in MDCK cells. In agreement with this observation, a significant portion of a GFP fusion of MAGI-1b localizes to the basolateral membrane of polarized MDCK cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain Chemistry
  • Cell Adhesion / physiology*
  • Cell Line
  • Conserved Sequence
  • Cross-Linking Reagents
  • Cytoskeletal Proteins / chemistry*
  • Cytoskeletal Proteins / physiology*
  • Dogs
  • Guanylate Kinases
  • Mice
  • Nucleoside-Phosphate Kinase / chemistry*
  • Nucleoside-Phosphate Kinase / genetics
  • Nucleoside-Phosphate Kinase / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Sequence Deletion
  • Trans-Activators*
  • Transfection
  • beta Catenin


  • CTNNB1 protein, mouse
  • Cross-Linking Reagents
  • Cytoskeletal Proteins
  • Recombinant Proteins
  • Trans-Activators
  • beta Catenin
  • Nucleoside-Phosphate Kinase
  • Guanylate Kinases