Requirement of PSD-95 for dopamine D1 receptor modulating glutamate NR1a/NR2B receptor function.
OBJECTIVE
To elucidate the role of scaffold protein postsynaptic density (PSD)-95 in the dopamine D1 receptor (D1R)-modulated NR1a/NR2B receptor response.


METHODS
The human embryonic kidney 293 cells expressing D1R (tagged with the enhanced yellow fluorescent protein) and NR1a/NR2B with or without co-expression of PSD-95 were used in the experiments. The Ca2+ influx measured by imaging technique was employed to monitor N-methyl-D-aspartic acid receptors (NMDAR) function.


RESULTS
The application of dopamine (DA, 100 micromol/L) did not alter glutamate/glycine (Glu/Gly)-induced NMDAR-mediated Ca2+ influx in cells only expressing the D1R/NR1a/NR2B receptor. However, DA increased Glu/Gly-induced Ca2+ influx in a concentration-dependent manner while the cells were co-expressed with PSD-95. D1R-stimulated Ca2+ influx was inhibited by a selective D1R antagonist SCH23390. Moreover, pre-incubation with either the protein kinase A (PKA) inhibitor H89, or the protein kinase C (PKC) inhibitor chelerythrine attenuated D1R-enhanced Ca2+ influx induced by the N-methyl-D-aspartic acid (NMDA) agonist. The results clearly indicate that D1R-modulated NR1a/NR2B receptor function depends on PSD-95 and is subjected to the regulation of PKA and PKC.


CONCLUSIONS
The present study provides the first evidence that PSD-95 is essential in D1R-regulated NR1a/NR2B receptor function.
Gu
Wei-Hua
WH
Department of Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China.
Yang
Shen
S
Shi
Wei-Xing
WX
Jin
Guo-Zhang
GZ
Zhen
Xue-Chu
XC
D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D000076122:Disks Large Homolog 4 Protein; D004298:Dopamine / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000235:genetics / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*
C501444:DLG4 protein, human; D000076122:Disks Large Homolog 4 Protein; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C409466:NR1 NMDA receptor; C121001:NR2B NMDA receptor; D017447:Receptors, Dopamine D1; D016194:Receptors, N-Methyl-D-Aspartate; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D002118:Calcium; D004298:Dopamine