SIGNAL TRANSDUCTION BY G-PROTEINS IN THE RETINAL PE

这项建议中提出的研究的目标是获得一个 对视网膜色素的协调生理学的认识 上皮(RPE)和神经视网膜。在众多RPE功能中 对于神经视网膜的生存至关重要的是吞噬 一包包脱落的感光细胞膜。拟议的研究重点是 RPE吞噬细胞的信号转导过程，以及 是基于一种假设，即鸟嘌呤介导的信号事件 核苷酸结合蛋白(G蛋白)可能在 RPE和光感受器之间的相互作用。具体目标是： 1)鉴定存在的G蛋白和G蛋白偶联受体 通过克隆和测序相应的cDNA来获得RPE。2)设立 G蛋白和G蛋白的组织特异性和亚细胞定位 蛋白质偶联受体。3)表征RPE特异性的功能 蛋白质并探讨它们在信号转导中的潜在作用 与吞噬有关的过程。试验性战略将是 基于分子生物学的技术，并将利用高 G蛋白之间和G蛋白之间存在的同源性程度 感受器。Northern分析、原位杂交和 免疫细胞化学将用于确定组织特异性和 亚细胞定位。配体结合和吞噬作用的检测将 用于确定RPE特异性蛋白的功能。这项研究 将有助于定义信号潜能和细胞 分子水平上的RPE生物学。长期目标是建立联系 这种对视网膜变性的根本原因的认识，在 RPE和视网膜之间的关系中断。

The objective of the research set out in this proposal is to gain an understanding of the coordinate physiology of the retinal pigment epithelium (RPE) and the neural retina. Among the many RPE functions critical for the viability of the neural retina is the phagocytosis of packets of shed photoreceptor membranes. The proposed research focuses on the signal transduction processes underlying phagocytosis by the RPE, and is based on the hypothesis that signaling events mediated by Guanine nucleotide-binding proteins (G-proteins) may play a specific role in the interactions between the RPE and photoreceptors. The specific aims are: 1) To identify the G-proteins and G-protein-coupled receptors present in the RPE by cloning and sequencing corresponding cDNAs. 2) To establish the tissue specificity and subcellular localization of the G-proteins and G protein-coupled receptors. 3) To characterize the function of RPE specific proteins and explore their potential roles in the signal transduction processes associated with phagocytosis. The experimental strategy will be based in the techniques of molecular biology, and will make use of the high degree of homology that exists among the G-proteins and among the receptors. Northern analysis, in situ hybridization, and immunocytochemistry will be used to determine tissue specificity and subcellular localization. Assays of ligand binding and phagocytosis will be used to determine the function of RPE specific proteins. This research will contribute to the definition of the signaling potential and cell biology of the RPE on a molecular level. The long term goals are to relate this knowledge to the underlying causes of retinal degeneration, in which the relationship between the RPE and retina is interrupted.