REGULATION OF NEURONAL NICOTINIC ACETYLCHOLINE RECEPTOR

神经元烟碱乙酰胆碱受体的调节

基本信息

批准号：
2267405
负责人：
EVAN S DENERIS
金额：
$ 12.75万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1991
资助国家：
美国
起止时间：
1991-08-06 至 1995-07-31
项目状态：
已结题

项目摘要

Molecular cloning studies have identified gene families encoding functionally distinct heteromeric ligand-gated ion-channels. One such family of genes encodes subunits that are assembled into several functionally-distinct heteromeric neuronal nicotinic acetylcholine receptors. The nicotinic receptor subunit gene family is abundantly expressed in the vertebrate brain and peripheral nervous system. Each member has a unique pattern of expression, although these patterns overlap partially. Thus, this gene family is likely to encode multiple heteromeric receptors to subserve synaptic functions in numerous cholinergic pathways of the brain and periphery. This proposal is concerned with identifying the mechanisms that control vertebrate receptor subunit gene expression so that functionally distinct heteromeric nicotinic receptors can be assembled in different subsets of phenotypically distinct neurons. The experiments described are designed to: 1) identify the cis-acting elements that control neuronal nicotinic receptor subunit gene transcription in a neural-specific manner, 2) determine whether the influence of NGF on nicotinic receptor subunit RNAs is exerted at the level of transcription or RNA stability, 3) determine the influence of activity on receptor subunit gene expression, and 4) determine if changes in receptor subunit gene expression occur during periods of rapid synaptogenesis. The gene family encoding neuronal nicotinic receptor subunits are particularly amenable to the proposed investigation because its members are expressed in a wellcharacterized clonal cell line, PC12 and in the accessible and experimentally manipulatable sympathetic nervous system. The PC12 line provides a convenient cell culture system in which to begin characterizing transcription regulatory elements controlling ligand-gated ion-channel genes. Sympathetic ganglia provide an accessible experimental system of primary neurons for complementary in vivo and in vitro approaches to address the influence of cell-cell interactions on receptor subunit gene expression. Neuronal nicotinic receptor subunit genes and other ligand-gated ion-channel genes are co-expressed in numerous nuclei and cell layers of the brain. Common neuronal environments raise the possibility that the genes encoding different ligand-gated ion-channels share similar mechanisms of regulation. Thus, this investigation is likely to serve as a model for the regulation of other ligand-gated ion-channel genes, for which well-characterized and accessible experimental models systems are not as well developed. The investigation of nicotinic receptor gene expression will ultimately lead to an understanding of the importance of receptor gene regulatory mechanisms to the development of the nervous system and perhaps insight into the molecular mechanisms of neurological disorders which result from aberrant development.

分子克隆研究已经确定了基因家族编码功能不同的异源配体门控离子通道。一个这样的基因家族编码被组装成几个的亚基功能上赋予的杂体神经元烟碱乙酰胆碱受体。烟碱受体亚基基因家族大量在脊椎动物大脑和周围神经系统中表达。每个成员具有独特的表达方式，尽管这些模式部分重叠。因此，这个基因家族可能会编码多个杂体受体可在众多中提供突触功能大脑和周围的胆碱能途径。该提议涉及确定的机制控制脊椎动物受体亚基基因表达，从而在功能上不同的异源烟碱受体可以在不同的表型不同神经元的子集。所述的实验是设计为：1）确定控制神经元的顺式作用元件烟碱受体亚基基因转录以神经特异性方式， 2）确定NGF对烟碱受体亚基的影响是否 RNA在转录或RNA稳定性水平上施加3）确定活动对受体亚基基因表达的影响， 4）确定受体亚基基因表达的变化是否发生在快速突触发生的时期。编码神经元的基因家族烟碱受体亚基特别适合于建议调查是因为其成员以良好的表达方式表达克隆细胞系，PC12以及在可访问和实验中可操纵的交感神经系统。 PC12线提供了便利的细胞培养系统开始表征控制配体门控离子通道的转录调节元件基因。交感神经神经节提供了可访问的实验系统用于互补体内和体外方法的主要神经元解决细胞 - 细胞相互作用对受体亚基基因的影响表达。神经元烟碱受体亚基基因和其他配体门控离子通道基因在许多核和细胞中共表达大脑层。常见的神经元环境增加了可能性编码不同配体门控离子通道的基因共享相似调节机制。因此，这项调查可能会作为调节其他配体门控离子通道基因的模型，用于哪些特征良好且易于访问的实验模型系统不是也开发了。烟碱受体基因表达的研究将最终导致对受体基因重要性的理解神经系统发展的监管机制，也许深入了解神经系统疾病的分子机制由异常发展产生。