Selective reduction of a PDZ protein, SAP-97, in the prefrontal cortex of patients with chronic schizophrenia

J Neurochem. 2002 Nov;83(4):797-806. doi: 10.1046/j.1471-4159.2002.01181.x.

Abstract

Many postsynaptic density proteins carrying postsynaptic density-95/discs large/zone occludens-1 (PDZ) domain(s) interact with glutamate receptors to control receptor dynamics and synaptic plasticity. Here we examined the expression of PDZ proteins, synapse-associated protein (SAP) 97, postsynaptic density (PSD)-95, chapsyn-110, GRIP1 and SAP102, in post-mortem brains of schizophrenic patients and control subjects, and evaluated their contribution to schizophrenic pathology. Among these PDZ proteins, SAP97 exhibited the most marked change: SAP97 protein levels were decreased to less than half that of the control levels specifically in the prefrontal cortex of schizophrenic patients. In parallel, its binding partner, GluR1, similarly decreased in the same brain region. The correlation between SAP97 and GluR1 levels in control subjects was, however, altered in schizophrenic patients. SAP102 levels were also significantly reduced in the hippocampus of schizophrenic patients, but this reduction was correlated with sample storage time and post-mortem interval. There were no changes in the levels of the other PDZ proteins in any of the regions examined. In addition, neuroleptic treatment failed to mimic the SAP97 change. These findings suggest that a phenotypic loss of SAP97 is associated with the postsynaptic impairment in prefrontal excitatory circuits of schizophrenic patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Antipsychotic Agents / pharmacology
  • Chronic Disease
  • Discs Large Homolog 1 Protein
  • Disks Large Homolog 4 Protein
  • Female
  • Guanylate Kinases
  • Haloperidol / pharmacology
  • Hippocampus / chemistry
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Male
  • Membrane Proteins
  • Middle Aged
  • Nerve Tissue Proteins / analysis
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / metabolism*
  • Neuropeptides / analysis
  • Neuropeptides / biosynthesis
  • Nuclear Proteins*
  • Nuclear Receptor Coactivator 2
  • Nucleoside-Phosphate Kinase / analysis
  • Nucleoside-Phosphate Kinase / biosynthesis
  • Oxidation-Reduction
  • Prefrontal Cortex / chemistry
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / metabolism*
  • Protein Structure, Tertiary / physiology
  • Rats
  • Rats, Wistar
  • Receptors, AMPA / analysis
  • Receptors, AMPA / metabolism
  • Schizophrenia / metabolism*
  • Transcription Factors / analysis
  • Transcription Factors / biosynthesis

Substances

  • Adaptor Proteins, Signal Transducing
  • Antipsychotic Agents
  • DLG1 protein, human
  • DLG3 protein, human
  • Discs Large Homolog 1 Protein
  • Disks Large Homolog 4 Protein
  • Dlg1 protein, rat
  • Dlg3 protein, rat
  • Dlg4 protein, rat
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Mpp2 protein, rat
  • NCOA2 protein, human
  • Ncoa2 protein, rat
  • Nerve Tissue Proteins
  • Neuropeptides
  • Nuclear Proteins
  • Nuclear Receptor Coactivator 2
  • Receptors, AMPA
  • Transcription Factors
  • postsynaptic density proteins
  • Nucleoside-Phosphate Kinase
  • Guanylate Kinases
  • Haloperidol
  • glutamate receptor ionotropic, AMPA 1