Role of AIPL1 in Inherited Retinal Degenerative Disease

描述（由申请人提供）：本研究项目的长期目标是了解光导机械如何在外段（OS）中组装，运输和维护，作为预防和/或修复该过程出错时出现的缺陷的先决条件。我们认为蛋白脂质修饰在这一过程中起作用。我们假设蛋白质脂化是一个动态过程，对于组织和促进盘状膜光导途径中蛋白质之间的串导至关重要。我们将使用磷酸二酯酶-6 （PDE6）作为模型蛋白来验证这一假设。PDE6是杆状和锥状光感受器细胞光信号传递所需的关键效应酶。光感受器细胞纤毛OS中PDE6的缺失导致视力丧失并伴有快速变性。在人类中，OS中缺乏PDE6会导致各种致盲疾病，如视网膜色素变性、leber先天性黑内障和色盲。尽管我们知道PDE6作为一种效应酶在光导中的作用，但这种关键酶是如何在内节段组装、运输然后锚定在外节膜上的还不清楚。本项目提出的实验旨在解读蛋白脂化需求背后的机制，以及PDE6在视杆细胞和视锥细胞的生存和功能中的进一步加工。我们计划通过在表达PDE6突变形式或缺乏负责这些修饰的特定酶的动物模型中研究包括PDE6在内的脂化蛋白的功能、稳定性、组装和运输来实现这些目标。最后，我们将利用这些动物模型研究蛋白在锥体细胞中的转运机制。我们提出的研究与NEI的视网膜疾病计划一致，以“确定导致视网膜退行性疾病的突变的病理生理机制”。我们提出的研究奠定了一个框架，通过这个框架，我们可以了解各种致盲疾病背后的基础，并设计新的治疗方法来治疗它们。

DESCRIPTION (provided by applicant): The long term goal of this research program is to understand how the phototransduction machinery is assembled, transported and maintained in outer segment (OS), as a prerequisite for preventing and/or repairing defects that arise when this process goes awry. We believe protein lipid modification plays a role in this process. We hypothesize that lipidation of proteins is a dynamic process and is essential in organizing and facilitating cross-talk between proteins in the phototransduction pathway at disc membranes. We will use phosophodiesterase-6 (PDE6) as a model protein to test this hypothesis. PDE6 is the crucial effectors enzyme needed for light signaling in rod and cone photoreceptor cells. Absence of PDE6 in ciliated OS in photoreceptor cells leads to vision loss accompanied by rapid degeneration. In humans, lack of PDE6 in OS leads to various blinding diseases such as retinitis pigmentosa, leber congenital amaurosis and achromatopsia. Despite our knowledge about the role of PDE6 as an effectors enzyme in phototransduction, how this crucial enzyme is assembled in inner segments, transported and then anchored in outer segment membranes is not known. The experiments proposed in this project are aimed at deciphering the mechanism behind the need for protein lipidation and further processing of PDE6 in survival and function of rods and cones. We plan to accomplish these goals by investigating the function, stability, assembly and transport of lipidated proteins including PDE6, in animal models that either expresses mutant forms of PDE6 or in models that lack specific enzymes that are responsible for these modifications. Finally, we will investigate the protein transport mechanisms in cone cells using these animal models. Our proposed studies are aligned with Retinal Diseases Program of the NEI to "determine the pathophysiological mechanisms underlying mutations" that cause retinal degenerative diseases. Our proposed studies lay a framework by which we can understand the basis behind various blinding diseases and design novel therapies to treat them. PUBLIC HEALTH RELEVANCE: Survival and function of rod and cone cells in retina depends on efficient synthesis and transport of protein machinery from inner segments to ciliated outer segment. Defects in this process lead to debilitating blinding diseases in humans. This proposal will elucidate the role of protein lipid modification in trafficking and function of crucial proteis in rods and cones and lay a framework by which we can understand the basis behind blinding diseases and design novel treatments for these diseases.