Serotonin 5-HT2C receptor homodimerization is not regulated by agonist or inverse agonist treatment
Serotonin 5-HT2C receptor homodimerization is not regulated by agonist or inverse agonist treatment
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DOI：
10.1016/j.ejphar.2007.04.030
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发表时间：
2007-07-30
影响因子：
5
通讯作者：
Weaver, Barbara A.
中科院分区：
文献类型：
--
作者：
Herrick-Davis, Katharine;Grinde, Ellinor;Weaver, Barbara A.
5-HT2C受体是治疗焦虑症、抑郁症、精神分裂症和肥胖症的靶点。在此之前，我们证明了5-HT2C受体作为同源二聚体发挥作用。在这里，我们研究了激动剂和反向激动剂处理对两个自然产生的5-HT2C受体异构体同源二聚体状态的影响，其中一个没有基础活性(VGV)，另一个相对于G(αQ)信号具有构成活性(INI)。用免疫印迹法检测VGV和IN I同源二聚体的形成，用生物发光法和荧光共振能量转移法(BRET和FRET)检测活细胞中VGV和IN I同源二聚体的形成。Western blotting显示，在没有和存在5-羟色胺的情况下，VGV或INI亚型转染的HEK293细胞的同源二聚体受体种类比例相同。转染VGV或INI异构体的HEK293细胞的BRET比值相同，且不受5-羟色胺的调节。同样，无论在没有或存在5-羟色胺或氯氮平的情况下，表达VGV或INI亚型的细胞的FRET效率都是相同的。结果表明，5-HT2C受体形成同源二聚体，无论它们是处于非活性构象还是活性构象，并且不受药物治疗的调节。(C)2007 Elsevier B.V.保留所有权利。
Serotonin 5-HT2C receptors represent targets for therapeutics aimed at treating anxiety, depression, schizophrenia, and obesity. Previously, we demonstrated that 5-HT2C receptors function as homodimers. Herein, we investigated the effect of agonist and inverse agonist treatment on the homodimer status of two naturally occurring 5-HT2C receptor isciforms, one without basal activity (VGV) and one with constitutive activity (INI) with respect to G(alpha q) signaling. Cyan- and yellow-fluorescent proteins were used to monitor VGV and IN I homodimer formation by western blot, and in living cells using bioluminescence and fluorescence resonance energy transfer (BRET and FRET). Western blots of solubilized membrane proteins revealed equal proportions of homodimeric receptor species from HEK293 cells transfected with either the VGV or INI isoform in the absence and presence of 5-HT. BRET ratios measured in HEK293 cells transfected with the VGV or INI isoform were the same and were not modulated by 5-HT. Similarly, FRET efficiencies were the same regardless of whether measured in cells expressing the VGV or INI isoform in the absence or presence of 5-HT or clozapine. The results indicate that serotonin 5-HT2C receptors form homodimers regardless of whether they are in an inactive or active conformation and are not regulated by drug treatment. (C) 2007 Elsevier B.V. All rights reserved.