PATHOGENESIS OF ALZHEIMERS DISEASE

拟议研究的长期目标是了解 B-淀粉样前体蛋白（APP）在 阿尔茨海默病的发病机制。 最近的研究表明， APP是一种流动的膜蛋白， 细胞质分选信号。 APP的细胞质尾部含有一个 与6个残基LDLR相关的序列GYENPTY 内化信号 FDNPVY以及符合4-残基的区段YTSI 基于酪氨酸的内化共有序列。 这些信号 被位于不同位点的分子分选机器识别 并确定细胞内的运输途径 沿着路由哪个APP。 虽然有证据表明AB可以 由细胞表面表达的APP产生， 内部化是必需的，目前还不清楚这是否是排他性的。 甚至是导致AB产生的主要运输途径。 本申请的主要目的是确定如何 APP的运输影响AB的产生，APP是否 贩运受其他基因产物的调控， AD的发病机制 为了实现这些目标，PI将 新出现的概念和方法上的进展的优势 领域的膜蛋白分选，并将其应用于APP运输。 主要的实验方法将是利用转铁蛋白受体 (TR)嵌合体，包括APP-TR嵌合体，所有定量生化 并对膜蛋白进行形态学研究。 使用 的TR嵌合体允许这种受体-配体的独特性质 系统用于定义在各种条件下的膜蛋白运输 的实验条件。 修饰蛋白质的方法 通过研究TR嵌合体的贩运将用于确定 改变的APP运输如何影响AB生产。

The long term goal of the proposed research is to understand the role of the B- amyloid precursor protein (APP) trafficking in the pathogenesis of Alzheimer's disease. Recent studies have established that APP is an itinerant membrane protein which displays multiple cytoplasmic sorting signals. The cytoplasm tail of APP contains a sequence GYENPTY related to the 6-residue LDLR internalization signal FDNPVY as well as the segment YTSI which conforms the 4-residue tyrosine-based internalization consensus sequence. These signals are recognized by molecular sorting machinery located at different sites within the cell and determine the intracellular trafficking pathways along which APP is routed. Although there is evidence that AB can be generated from APP expressed on the cell surface and that internalization is required, it is unclear whether this is the exclusive or even the major trafficking pathway leading to the production of AB. The primary objectives of the present application are to determine how trafficking of APP influences AB production and whether APP trafficking is regulated by other gene products implicated in the pathogenesis of AD. To accomplish these goals, the PI will take advantage of emerging conceptual and methodological advances in the field of membrane protein sorting and apply them to APP trafficking. The major experimental approach will be to exploit transferrin receptor (TR) chimers including APP-TR chimera that all quantitative biochemical and morphological studies of membrane proteins to performed. The use of the TR chimeras allows unique properties of this receptor-ligand system to be used to define membrane protein trafficking under a variety of experimental conditions. The methods developed to modify protein trafficking through the study of TR chimeras will be used to determine how altered APP trafficking affects AB production.