Identifying regulators of APP gamma secretase

描述（由申请人提供）：阿尔茨海默病（AD）是一种脑神经退行性疾病，是老年痴呆症的最常见形式。导致AD的中心病理事件被认为是淀粉样蛋白斑块的积累，其主要由称为淀粉样蛋白β肽（A-β）的毒性肽组成。A-β通过两种蛋白酶的作用进行蛋白水解加工而衍生自APP，其中一种蛋白酶是γ分泌酶。γ分泌酶功能异常是最常见的早发性家族性AD的基础。γ分泌酶存在于一个大型多蛋白复合物中，该复合物具有四种必需成分：早老素、尼卡斯特罗蛋白、aph-1和pen-2。确定γ分泌酶活性调节的机制，应导致增加对AD发病机制的理解，并可能为开发新的诊断工具和治疗靶点提供见解。 果蝇作为分子遗传学工具，已被成功地用于鉴定新基因和研究重要的生物学过程。在果蝇中，γ分泌酶活性及其四个基本组分在功能上是保守的。因此，在果蝇中鉴定的γ分泌酶的调节子可能是功能保守的。我们已经开发了一个报告系统，在生活果蝇的眼睛，使我们能够可视化的γ分泌酶活性的内源性水平。使用这些苍蝇作为遗传背景，我们进行了遗传筛选，并确定了几个候选人进行进一步的特点。这项建议的具体目标是： 1.进行功能缺失筛选，克隆候选基因并描述其功能位点。 2.表征γ-分泌酶活性的功能获得性调节剂。 3.确定候选基因如何与编码γ-分泌酶复合物、aph-1、pen-2、nicastrin和早老素的基因相互作用

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a neurodegenerative disorder of the brain and the most common form of senile dementia. The central pathological event leading to AD is thought to be the accumulation of amyloid plaques consisting primarily of a toxic peptide known as amyloid beta peptide (A-beta) in the brain. A-beta is derived from APP by proteolytic processing via the action of two proteases, one of which is gamma secretase. The aberrant action of gamma secretase function underlies the most common early onset familial AD. Gamma secretase resides in a large multi-protein complex with four essential components: presenilin, nicastrin, aph-1 and pen-2. Identifying mechanisms by which gamma secretase activity is regulated should lead to an increased understanding of AD pathogenesis and may provide insight in developing new diagnostic tools and therapeutic targets. Drosophila has been used with great success as a molecular genetic tool to identify new genes and study essential biological processes. In Drosophila, the gamma secretase activity and its four essential components are functionally conserved. Thus regulators of gamma secretase identified in Drosophila are likely to be functionally conserved. We have developed a reporter system in the living Drosophila eye that allows us to visualize the endogenous level of gamma secretase activity. Using these flies as a genetic background, we have carried out genetic screens and have identified several candidates to be characterized further. The specific aims of this proposal are: 1. Carry out loss-of-function screens, clone candidate genes and characterize their sites of function. 2. Characterize gain-of-function modifiers of gamma-secretase activity. 3. Determine how the candidate gene interacts with genes encoding components of gamma-secretase complex, aph-1, pen-2, nicastrin and presenilin