RECEPTOR-EFFECTOR COUPLING OF SEROTONIN RECEPTORS

一种新型的5-羟色胺结合位点，5-HT1C位点，已经被 在哺乳动物的脉络丛中被鉴定。这个结合部位是 与激活磷脂酰肌醇周转(Conn ET)有关 等，Proc.娜塔莉。阿卡德。SCI。(1986))。在本申请中，我们建议 研究5-HT1C的分子和细胞后果 受体激活。我们将测量蛋白质的磷酸化， 钙离子转运活性与细胞内钙释放 受体激活。激动剂的效力将在此进行检验。 系统和肌醇磷酸生成的时间进程(IP， IP2、IP3)以及GTP的效果将被确定，以便 更好地定义受体之后的事件顺序 激活。 一种有前途的5-HT1C研究新模型体系 受体将在这一提议下进行表征和开发。 脉络丛肿瘤在转基因成人中自发发展 将SV40早期区域基因的拷贝整合到 他们的基因组。转基因小鼠可以将这种特征传递给他们的 产生肿瘤的小鼠的后代和稳定系已经被 制作。我们最近发现脉络丛 转基因小鼠的肿瘤表达高水平的5-羟色胺5- HT1C受体。我们建议确定5-HT1C 受体仍与肌醇磷脂的水解酶偶联 系统在肿瘤中的作用和比较受体效应偶联 这一过程将组织转化为正常的脉络丛。此外, 原代细胞培养将从肿瘤中制备出来，我们 将尝试分离表达5- 这些培养物中的HT1C受体。这些文化将被用于 作为研究5-HT1C受体的模型系统 活细胞中的动力学和受体-效应器耦合。 这些研究将提供有关受体效应器的信息 与磷脂酰肌醇偶联的普遍适用性 神经递质受体。关于生物多样性的基础性研究 脉络丛5-HT1C受体的特性也可能导致 为了更好地理解脉络丛的两个关键作用： 脑脊液的调理生产与维护 血脑屏障通过脉络丛起作用。是这样的 信息可能导致治疗该病的新策略 脑积水或治疗药物的新方法 大脑。

A novel type of serotonin binding site, the 5-HT1C site, has been identified in the mammalian choroid plexus. This binding site is coupled to activation of phosphatidylinositol turnover (Conn et al., Proc. Natl. Acad. Sci. (1986)). In this application we propose to study the molecular and cellular consequences of 5-HT1C receptor activation. We shall measure protein phosphorylation, ion transport activities and intracellular calcium release following receptor activation. Agonist potencies will be examined in this system and the time course of inositol phosphate generation (IP, IP2, IP3) and the effect of GTP will be determined in order to better define the sequence of events which follow receptor activation. A promising new model system for the study of the 5-HT1C receptor will be characterized and developed under this proposal. Choroid plexus tumors develop spontaneously in adult transgenic mice which have integrated copies of SV40 early region genes into their genome. Transgenic mice can pass this trait to their offspring and stable lines of tumor-generating mice have been produced. We have recently discovered that choroid plexus tumors from transgenic mice express high levels of serotonin 5- HT1C receptors. We propose to determine if the 5-HT1C receptor remains coupled to the phosphoinositide hydrolysis system in the tumor and to compare receptor effector coupling in this transformed tissue to normal choroid plexus. In addition, primary cell cultures will be prepared from the tumors and we shall attempt to isolate a continuous cell line expressing the 5- HT1C receptor from these cultures. These cultures will be used as a model systems for the investigation of 5-HT1C receptor dynamics and receptor-effector coupling in living cells. These studies will provide information on receptor-effector coupling with general applicability to phosphoinositide-linked neurotransmitter receptors. Fundamental studies on the properties of this choroid plexus 5-HT1C receptor may also lead to better understanding of two key roles of the choroid plexus: modulation of cerebrospinal fluid production and maintenance of blood-brain barrier functions by the choroid plexus. Such information could lead to new strategies for the treatment of hydrocephalus or new methods of delivering therapeutic agents to the brain.