G PROTEINS AND PHOSPHOLIPASE C REGULATION IN RPE CELLS

RPE 细胞中 G 蛋白和磷脂酶 C 的调节

• 批准号: 3265659
• 负责人: HENRY K FONG
• 金额: $ 16.8万
• 依托单位: DOHENY EYE INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1993-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3265659
• 关键词: Escherichia; G protein; antibody inhibitor; biological signal transduction; cell transformation; cell type; chemotaxis; chromatography; complementary DNA; cow; gene expression; genetic library; genetic transcription; growth factor; human tissue; laboratory rabbit; messenger RNA; molecular cloning; nucleic acid hybridization; nucleic acid probes; peptides; pertussis toxin; phagocytosis; phosphatidylinositols; phospholipase C; protein biosynthesis; retina; retinal pigment epithelium; retinaldehyde; western blottings

Guanine nucleotide regulatory proteins (G proteins) are a family of homologous polypeptides that are required for receptor-mediated regulation of retinal cGMP phosphodiesterase, adenylyl cyclase, phospholipases C and A2, and subsets of K+ and Ca2+ ion channels. These signal-transducing molecules are involved in fundamental processes of cell modulation, as well as in highly specialized cell function, such as phototransduction and olfaction. Little is known about specific G proteins and the molecular biology of signal transduction in retinal pigment epithelial (RPE) cells. The RPE is a highly specialized monolayer of cells with a close functional relationship with photoreceptors. The multiple functions of the RPE, if disturbed, may lead to a variety of visual disorders, including serous retinal detachment and retinal degeneration. In proliferative vitreoretinopathy, RPE cells are believed to undergo abnormal chemotaxis, migration, and proliferation. A hypothesis of this proposal is that important behaviors of phagocytic RPE cells, such as chemotaxis, transformation, and proliferation, involve regulation by G proteins and phosphoinositide phospholipase C, since these signal-transducing molecules are the basis for the regulation of similar activities that have been studied intensively in macrophages, neutrophils, and other cell types. The long-term goal of this study is to determine the molecular basis for the regulation of phosphoinositide phospholipase C by RPE GTP-binding proteins and to develop specific reagents that interact with these signal-transducing molecules to modify cell response. To achieve the goals of this project, RPE cells from bovine and human tissue will be cultured by established methods. In these cultured cells, the regulation of phospholipase C by chemoattractants and growth factors will be studied, and the expression of RPE G proteins will be analyzed by molecular genetics. In addition, a human RPE cDNA library will be constructed from homogeneous cell cultures for the identification of novel G protein gene products in RPE. The effects of G protein antagonists, such as pertussis toxin, synthetic peptides, and inhibitory antibodies, on phospholipase C and RPE cell responses will be determined. This work may provide a basis for the rational development of reagents or drugs that interact with specific G proteins and other signal-transducing molecules in RPE.

鸟嘌呤核苷酸调节蛋白（G蛋白）是一个家族， 受体介导调节所需的同源多肽 视网膜cGMP磷酸二酯酶，腺苷酸环化酶，磷脂酶C和 A2，以及K+和Ca2+离子通道的子集。这些信号传导 分子也参与细胞调节的基本过程， 如在高度特化的细胞功能中，如光传导和 嗅觉 对特定的G蛋白和G蛋白的分子生物学知之甚少。 视网膜色素上皮（RPE）细胞中的信号转导。RPE是一种 具有密切功能关系的高度特化的单层细胞 有光感受器。RPE的多种功能如果受到干扰， 导致多种视觉障碍，包括浆液性视网膜脱离 和视网膜变性。在增殖性玻璃体视网膜病变中，RPE细胞是 被认为经历异常的趋化性、迁移和增殖。一 该建议假设是吞噬RPE的重要行为 细胞，如趋化性，转化和增殖， G蛋白和磷脂酰肌醇磷脂酶C的调节，因为这些 信号转导分子是调节类似的 在巨噬细胞，中性粒细胞， 和其他细胞类型。本研究的长期目标是确定 磷酸肌醇磷脂酶C调节的分子基础 RPE GTP结合蛋白，并开发相互作用的特异性试剂 与这些信号转导分子一起改变细胞反应。 为了实现本项目的目标， 将通过已建立的方法培养组织。在这些培养的细胞中， 趋化因子和生长因子对磷脂酶C调控 将进行研究，并通过分析RPE G蛋白的表达， 分子遗传学此外，还将构建人RPE cDNA文库。 从同质细胞培养物构建，用于鉴定新的 RPE中G蛋白基因产物。G蛋白拮抗剂的作用，如 作为百日咳毒素、合成肽和抑制性抗体， 将测定磷脂酶C和RPE细胞应答。这项工作可能 为合理开发试剂或药物提供依据， 与特定的G蛋白和其他信号转导分子相互作用， RPE。