PSD-95 assembles a ternary complex with the N-methyl-D-aspartic acid receptor and a bivalent neuronal NO synthase PDZ domain

J Biol Chem. 1999 Sep 24;274(39):27467-73. doi: 10.1074/jbc.274.39.27467.

Abstract

Nitric oxide (NO) biosynthesis in cerebellum is preferentially activated by calcium influx through N-methyl-D-aspartate (NMDA)-type glutamate receptors, suggesting that there is a specific link between these receptors and neuronal NO synthase (nNOS). Here, we find that PSD-95 assembles a postsynaptic protein complex containing nNOS and NMDA receptors. Formation of this complex is mediated by the PDZ domains of PSD-95, which bind to the COOH termini of specific NMDA receptor subunits. In contrast, nNOS is recruited to this complex by a novel PDZ-PDZ interaction in which PSD-95 recognizes an internal motif adjacent to the consensus nNOS PDZ domain. This internal motif is a structured "pseudo-peptide" extension of the nNOS PDZ that interacts with the peptide-binding pocket of PSD-95 PDZ2. This asymmetric interaction leaves the peptide-binding pocket of the nNOS PDZ domain available to interact with additional COOH-terminal PDZ ligands. Accordingly, we find that the nNOS PDZ domain can bind PSD-95 PDZ2 and a COOH-terminal peptide simultaneously. This bivalent nature of the nNOS PDZ domain further expands the scope for assembly of protein networks by PDZ domains.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Cell Line
  • Cell Membrane / physiology
  • Cell Membrane / ultrastructure
  • Circular Dichroism
  • Cloning, Molecular
  • Disks Large Homolog 4 Protein
  • Guanidine / pharmacology
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Macromolecular Substances
  • Membrane Proteins
  • Models, Molecular
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / metabolism*
  • Nitric Oxide Synthase / chemistry
  • Nitric Oxide Synthase / metabolism*
  • Nitric Oxide Synthase Type I
  • Prosencephalon / metabolism*
  • Protein Conformation
  • Rats
  • Receptors, N-Methyl-D-Aspartate / chemistry
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Transfection

Substances

  • Disks Large Homolog 4 Protein
  • Dlg4 protein, rat
  • Intracellular Signaling Peptides and Proteins
  • Macromolecular Substances
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Receptors, N-Methyl-D-Aspartate
  • Recombinant Proteins
  • postsynaptic density proteins
  • NOS1 protein, human
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type I
  • Nos1 protein, rat
  • Guanidine