Structure -Function Studies of Rhodopsin

描述（由申请人提供）：本提案的重点是视觉色素视紫红质的结构和功能。有两个具体目标： 1.重组野生型和突变型视紫红质的三维结晶和x-射线结构测定。虽然牛视紫红质的X射线晶体结构在几年前就已经解决了，但该研究中使用的蛋白质是从天然来源中分离出来的。至今还没有人能从重组体中结晶出视紫红质。这是一个重要的目标，因为一旦实现，它将允许视紫红质突变体的高分辨率结构分析。视紫红质突变体的结构分析是从根本上了解这种蛋白质功能的关键下一步。在这项工作中最感兴趣的突变体将是那些在视网膜疾病视网膜色素变性和先天性夜盲症中发现的突变体，特别是那些组成型激活蛋白质的突变体。 2.利用转基因非洲爪蟾研究视紫红质及其下游信号转导蛋白基因突变引起视网膜病变的分子机制。本目标的主要重点将放在疾病，视网膜色素变性。

DESCRIPTION (provided by applicant): The focus of this proposal is on the structure and function of the visual pigment rhodopsin. There are two Specific Aims: 1. The 3-dimensional crystallization and x-ray structure determination of recombinant wild-type and mutant rhodopsins. While the x-ray crystal structure of bovine rhodopsin was solved several years ago, the protein used in that study was isolated from native sources. No one has as yet crystallized rhodopsin from a recombinant source. This is an important goal because once achieved it will allow a high resolution structural analysis of rhodopsin mutants. Structural analysis of rhodopsin mutants is a crucial next step for a fundamental understanding of the functioning of this protein. The mutants of greatest interest in this work will be those found in the retinal diseases retinitis pigmentosa and congenital night blindness, specifically those that constitutively activate the protein. 2. To use transgenic Xenopus laevis to explore the molecular mechanisms of retinal disease arising from mutations in the genes for rhodopsin and its downstream signaling component transducin. The main focus of this Aim will be on the disease, retinitis pigmentosa.