The PDZ-binding domain is essential for the dendritic targeting of 5-HT2A serotonin receptors in cortical pyramidal neurons in vitro

Neuroscience. 2003;122(4):907-20. doi: 10.1016/s0306-4522(03)00589-x.

Abstract

The 5-HT(2A) serotonin receptor represents an important molecular target for atypical antipsychotic drugs and for most hallucinogens. In the mammalian cerebral cortex, 5-HT(2A) receptors are enriched in pyramidal neurons, within which 5-HT(2A) receptors are preferentially sorted to the apical dendrites. In primary cortical cultures, 5-HT(2A) receptors are sorted to dendrites and not found in the axons of pyramidal neurons. We identified a sorting motif that mediates the preferential targeting of 5-HT(2A) receptors to the dendrites of cortical pyramidal neurons in vitro. We constructed green fluorescent protein-tagged 5-HT(2A) receptors wherein potential sorting motifs were disrupted, and subsequently employed either the Semliki Forest virus or calcium phosphate for the transient expression of recombinant 5-HT(2A) receptors in cultured cortical pyramidal neurons. Using dual-labeling immunofluorescent confocal microscopy, we quantified the axonal and dendritic sorting patterns of endogenous and recombinant 5-HT(2A) receptors. We discovered that disruption of the PDZ-binding domain of the 5-HT(2A) receptor greatly attenuates the dendritic targeting of 5-HT(2A) receptors without inappropriately sorting 5-HT(2A) receptors to axons. The PDZ-binding domain is therefore a necessary signal for the preferential targeting of the 5-HT(2A) receptor to the dendritic compartment of cultured cortical pyramidal neurons, the first such role ascribed to this protein-protein interaction motif of any G protein-coupled receptor.

MeSH terms

  • Animals
  • Binding Sites / physiology
  • Cell Line
  • Cerebral Cortex / metabolism*
  • Cerebral Cortex / physiology
  • Cricetinae
  • Dendrites / metabolism*
  • Humans
  • Nerve Tissue Proteins / metabolism
  • Protein Binding / physiology
  • Protein Structure, Tertiary / physiology
  • Pyramidal Cells / metabolism*
  • Pyramidal Cells / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Serotonin, 5-HT2A / genetics
  • Receptor, Serotonin, 5-HT2A / metabolism*
  • Serotonin 5-HT2 Receptor Agonists
  • Serotonin Receptor Agonists / pharmacology
  • Transfection

Substances

  • Nerve Tissue Proteins
  • Receptor, Serotonin, 5-HT2A
  • Serotonin 5-HT2 Receptor Agonists
  • Serotonin Receptor Agonists