Tamalin is a scaffold protein that interacts with multiple neuronal proteins in distinct modes of protein-protein association

J Biol Chem. 2003 Apr 25;278(17):14762-8. doi: 10.1074/jbc.M300184200. Epub 2003 Feb 13.


Tamalin is a scaffold protein that comprises multiple protein-interacting domains, including a 95-kDa postsynaptic density protein (PSD-95)/discs-large/ZO-1 (PDZ) domain, a leucine-zipper region, and a carboxyl-terminal PDZ binding motif. Tamalin forms a complex with metabotropic glutamate receptors and guanine nucleotide exchange factor cytohesins and promotes intracellular trafficking and cell surface expression of group 1 metabotropic glutamate receptors. In the present study, using several different approaches we have shown that tamalin interacts with multiple neuronal proteins through its distinct protein-binding domains. The PDZ domain of tamalin binds to the PDZ binding motifs of SAP90/PSD-95-associated protein and tamalin itself, whereas the PDZ binding motif of tamalin is capable of interacting with the PDZ domain of S-SCAM. In addition, tamalin forms a complex with PSD-95 and Mint2/X11beta/X11L by mechanisms different from the PDZ-mediated interaction. Tamalin has the ability to assemble with these proteins in vivo; their protein complex with tamalin was verified by coimmunoprecipitation of rat brain lysates. Interestingly, the distinct protein-interacting domains of tamalin are evolutionarily conserved, and mRNA expression is developmentally up-regulated at the postnatal period. The results indicate that tamalin exists as a key element that forms a protein complex with multiple postsynaptic and protein-trafficking scaffold proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Amino Acid Sequence
  • Animals
  • Cadherins*
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism*
  • Carrier Proteins / physiology
  • Conserved Sequence
  • Disks Large Homolog 4 Protein
  • Guanylate Kinases
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / metabolism*
  • Neurons / chemistry
  • Protein Binding
  • Protein Structure, Tertiary
  • Rats
  • SAP90-PSD95 Associated Proteins
  • Sequence Alignment


  • Adaptor Proteins, Signal Transducing
  • Apba2 protein, rat
  • Cadherins
  • Carrier Proteins
  • DLG4 protein, human
  • Disks Large Homolog 4 Protein
  • Dlg4 protein, rat
  • Intracellular Signaling Peptides and Proteins
  • Magi2 protein, rat
  • Membrane Proteins
  • Nerve Tissue Proteins
  • SAP90-PSD95 Associated Proteins
  • postsynaptic density proteins
  • tamalin protein, human
  • Guanylate Kinases