MOLECULAR AND FUNCTIONAL ANALYSIS OF ATP RECEPTORS

描述：（研究者摘要）过去积累的证据 三十年来，三磷酸腺苷（ATP）作为一种 神经递质/神经调质在许多肾上腺素能，胆碱能和 非肾上腺素能/非胆碱能途径。 它作为一种化学媒介， 细胞间通讯已经在组织中建立， 中枢和外周神经系统，内分泌腺，心脏和平滑 肌肉. 然而，作为一种化学物质， 对信号的理解很少。 其中一个主要原因是， 大多数组织中存在多种受体亚型， 亚型选择性激动剂和拮抗剂。 此外，在某些组织中， 有高水平的细胞表面酶（胞外ATP酶）， 快速降解许多用于受体分类的ATP类似物， 导致进一步的并发症。 为了清楚地了解角色 对于ATP介导的传递，必须确定其药理学作用。 和ATP受体的生理特性。 目前，ATP受体 属于两种类型之一，P2 γ和P2 x受体。 重点 其中最重要的是属于p2 x类别的ATP受体。 这些 受体是配体门控通道，不仅可渗透 一价阳离子如Na+和K+，但也包括Ca+。 在这个项目中， 调查人员将规避与以下方面有关的困难： 研究多种受体亚型在其自然环境中， 在哺乳动物细胞中重组受体表达的用途。 这 这种方法允许在细胞中表达单个受体亚型， 控制环境，从而允许详细表征 受体亚单位的基本性质。 申请人已经开始了P2 x受体的研究， 使用比较和对比方法， 利用新的P2 x受体亚基，他们最近从 大脑和心脏 此外，他们将阐明拓扑 膜内蛋白质的构象和亚基组成 受体的组装。 他们还将寻找其他蛋白质， 参与功能性集会的形成。 这些实验 将提供有关P2 x受体功能的基本信息， ATP作为神经递质在中枢和外周神经系统中的作用 系统. 该项目的总体目标是提供一个更清晰的 了解相关的药理学和生理学特性 与特定的P2 x受体亚型。

DESCRIPTION: (Investigator's Abstract) Evidence accumulated over the past three decades supports the role of adenosine-triphosphate (ATP) as a neurotransmitter/neuromodulator in many adrenergic, cholinergic and non-adrenergic/non-cholinergic pathways. Its role as a chemical mediator of intercellular communication has been established in tissues such as the central and peripheral nervous systems, endocrine glands, heart and smooth muscle. However, the mechanisms which mediate ATP's role as a chemical signal is poorly understood. A primary reason for this is the presence of multiple receptor subtypes in most tissues coupled with a lack of subtype-selective agonists and antagonists. Additionally, in some tissues there are high levels of cell-surface enzymes (ecto-ATPases) that can quickly degrade many of the ATP analogues used for receptor classification, resulting in further complications. In order to clearly understand the role of ATP-mediated transmission, it is essential to define the pharmacological and physiological properties of ATP receptors. Currently, ATP receptors fall into one of two classifications, P2gamma and P2x receptors. The focus of this grant is the ATP receptors which belong to the p2x category. These receptors are ligand-gated channels that are permeable not only to monovalent cations such as Na+ and K+, but also to Ca+. In this project, the investigators will circumvent the difficulties associated with investigating multiple receptor subtypes in their native settings through the use of recombinant receptor expression in mammalian cells. This approach allows for the expression of individual receptor subtypes in a controlled environment, thus permitting detailed characterization of the basic properties of a receptor subunit. The applicants have embarked on the investigation of P2x receptors at the molecular and functional level using a compare and contrast methodology, utilizing novel P2x receptor subunits that they have recently cloned from brain and heart. In addition, they will elucidate the topological conformation of the proteins within the membrane and the subunit composition of receptor assemblies. They will also search for additional proteins that participate in the formation of functional assemblies. These experiments will provide essential information regarding P2x receptor function and the role of ATP as a neurotransmitter in the central and peripheral nervous systems. The overall goal of this project is to provide a clearer understanding of the pharmacological and physiological properties associated with specific P2x receptor subtypes.