Regulation of dopamine D1 receptor trafficking and desensitization by oligomerization with glutamate N-methyl-D-aspartate receptors
Regulation of dopamine D1 receptor trafficking and desensitization by oligomerization with glutamate N-methyl-D-aspartate receptors
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DOI：
10.1074/jbc.m213140200
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发表时间：
2003-05-30
影响因子：
4.8
通讯作者：
Missale, C
中科院分区：
文献类型：
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作者：
Fiorentini, C;Gardoni, F;Missale, C
多巴胺D-1受体的激活对于谷氨酸诱导的皮质纹状体突触长时程增强的产生至关重要。在这项研究中，我们报告说，在纹状体神经元中，D-1受体共定位与N-甲基-D-天冬氨酸（NMDA）受体在突触后密度，他们共免疫沉淀与NMDA受体亚基从突触后密度制剂。使用改进的生物发光共振能量转移，我们表明，D-1和NMDA受体簇反映了直接相互作用的存在。标记的D-1受体和NR 1亚基共转染COS-7细胞产生了显着的生物发光共振能量转移信号，是不敏感的激动剂刺激，并没有改变在NR 2B亚基的存在下，表明D-1受体组成性和选择性地与NMDA通道的NR 1亚基相互作用。与NR 1亚基的寡聚化基本上改变了D-1受体的运输。在单独转染的HEK 293细胞中，NR 1定位于内质网，而D-1受体靶向质膜。在共转染细胞中，D-1受体和NR 1亚基都保留在胞质区室中。在NR 2B亚基存在下，NR 1-D-1受体复合物被易位到质膜。这些数据表明，D-1和NMDA受体组装在细胞内室作为组成型异聚体复合物，被传递到功能位点。与NR 1和NR 2B亚基的共表达也废除了激动剂诱导的D-1受体胞质隔离，表明与NMDA受体的寡聚化可以代表一种新的调节机制，调节D-1受体脱敏和细胞运输。
Activation of dopamine D-1 receptors is critical for the generation of glutamate-induced long-term potentiation at corticostriatal synapses. In this study, we report that, in striatal neurons, D-1 receptors are co-localized with N-methyl-D-aspartate ( NMDA) receptors in the postsynaptic density and that they co-immunoprecipitate with NMDA receptor subunits from postsynaptic density preparations. Using modified bioluminescence resonance energy transfer, we demonstrate that D-1 and NMDA receptor clustering reflects the existence of direct interactions. The tagged D-1 receptor and NR1 subunit cotransfected in COS-7 cells generated a significant bioluminescence resonance energy transfer signal that was insensitive to agonist stimulation and that did not change in the presence of the NR2B subunit, suggesting that the D-1 receptor constitutively and selectively interacts with the NR1 subunit of the NMDA channel. Oligomerization with the NR1 subunit substantially modified D-1 receptor trafficking. In individually transfected HEK293 cells, NR1 was localized in the endoplasmic reticulum, whereas the D-1 receptor was targeted to the plasma membrane. In cotransfected cells, both the D-1 receptor and NR1 subunit were retained in cytoplasmic compartments. In the presence of the NR2B subunit, the NR1-D-1 receptor complex was translocated to the plasma membrane. These data suggest that D-1 and NMDA receptors are assembled within intracellular compartments as constitutive heteromeric complexes that are delivered to functional sites. Coexpression with NR1 and NR2B subunits also abolished agonist-induced D-1 receptor cytoplasmic sequestration, indicating that oligomerization with the NMDA receptor could represent a novel regulatory mechanism modulating D-1 receptor desensitization and cellular trafficking.