The PDZ-binding domain is essential for the dendritic targeting of 5-HT2A serotonin receptors in cortical pyramidal neurons in vitro.
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.
Xia
Z
Z
Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
Hufeisen
S J
SJ
Gray
J A
JA
Roth
B L
BL
D000818:Animals; D001665:Binding Sites / Q000502:physiology; D002460:Cell Line; D002540:Cerebral Cortex / Q000378:metabolism* / Q000502:physiology; D006224:Cricetinae; D003712:Dendrites / Q000378:metabolism*; D006801:Humans; D009419:Nerve Tissue Proteins / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D017966:Pyramidal Cells / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A / Q000235:genetics / Q000378:metabolism*; D058826:Serotonin 5-HT2 Receptor Agonists; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D014162:Transfection
D009419:Nerve Tissue Proteins; D044402:Receptor, Serotonin, 5-HT2A; D058826:Serotonin 5-HT2 Receptor Agonists; D017366:Serotonin Receptor Agonists