PHOTORECEPTION AND TRANSDUCTIONS IN VISION

我们研究的目的是研究 光感受和光感受器细胞中的传导。 在这五年里， 计划，我们提出了解决以下两个具体目标的实验： 1.重组DNA片段的体外表达和诱变 编码分子光感受器视紫红质将被应用于检查 其结构和活动。 在E.大肠杆菌和哺乳动物细胞 本文提出 视紫红质和相应的突变受体将被 检查了结构折叠、吸收调节 波长，以及胞质结构域与 cGMP级联的组分，例如G蛋白、视蛋白激酶和 48 K蛋白。 2.两种光感受器的分离和表征技术 质膜大分子、Na ~+/Ca ~（++）交换体和质膜透性 cGMP/光依赖性离子通道，其控制细胞信号传导， 概述。 我们建议识别和表征基因和mRNA 编码每个分子，以识别预测的蛋白质结构， 从遗传信息中获得，并最终在体外使用 表达和诱变，以研究其结构和功能 活动 我们的长期研究目标是发展重组DNA技术 以补充传统的生物化学分离/表征方法 用于研究视觉传导中的蛋白质功能。 正如aim中所指出的那样， 2，这些技术将使我们能够研究蛋白质的重要性， 视觉功能，但每个细胞中只有少数拷贝。 另外我们 我希望发起研究，使我们能够研究 视网膜中编码视觉传导蛋白的基因。 这些研究 贡献了光感受器中大分子的基本信息， 在某种程度上受到视网膜色素变性遗传缺陷的影响， 视网膜母细胞瘤

The objective of our research is to examine the molecular basis of photoreception and transduction in photoreceptor cells. In this five year plan, we propose experiments addressing the following two specific aims: 1. In vitro expression and mutagenesis of recombinant DNA fragments encoding the molecular photoreceptor rhodopsin will be applied to examine its structure and activity. Expression in both E. coli and mammalian cells is proposed. Rhodopsin and the corresponding mutant receptors will be examined for properties of structural folding, regulation of absorption wavelength, and functional interactions of the cytoplasmic domains with components of the cGMP cascade, e.g. G-protein, opsin kinase, and 48K-protein. 2. Techniques for isolation and characterization of two photoreceptor plasma membrane macromolecules, the Na+/Ca++ exchanger and the cGMP/light-dependent ion channel, that control cell signaling are outlined. We propose to identify and characterize the genes and mRNA encoding each of the molecules, to identify the predicted protein structure from genetic information obtained, and eventually to use in vitro expression and mutagenesis to study their structure and functional activities. Our long term research objective is to develop recombinant DNA techniques to supplement traditional biochemical isolation/characterization methods for study of proteins functional in visual transduction. As noted in aim 2, such techniques would enable us to study proteins that are important for visual function but present in only few copies per cell. In addition, we wish to initiate studies that will enable us to study the expression of genes encoding visual transduction proteins in the retina. These studies contribute basic information about macromolecules in photoreceptors that are somehow affected by genetic defects in retinitis pigmentosa or retinoblastomas.