Roles of PEN-2 and APH-1 in PS1 complex formation

PEN-2 和 APH-1 在 PS1 复合物形成中的作用

• 批准号: 6985373
• 负责人: WENJIE LUO
• 金额: $ 2.95万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-10-01 至 2006-03-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6985373
• 关键词: Alzheimer' s disease; Golgi apparatus; SDS polyacrylamide gel electrophoresis; amyloid proteins; cell line; endopeptidases; endoplasmic reticulum; enzyme activity; enzyme linked immunosorbent assay; enzyme mechanism; gene mutation; immunoprecipitation; intermolecular interaction; polymerase chain reaction; postdoctoral investigator; presenilin; protein folding; protein structure function; western blottings

DESCRIPTION (provided by applicant): Genetic mutations in genes encoding presenilins (PS1 and PS2) are responsible for the majority of early-onset familial AIzheimer's disease (FAD). Extensive studies in the past few years focusing on the mechanisms by which mutant PS promote AD pathogenesis have demonstrated that PS1 is a key component of gamma-secretase complex, an unusual protease catalyzing the intramembrane cleavage of amyloid precursor protein (APP) and generating pathogenic small peptide Abeta. Nascent full length PS1 polypeptides undergo endoproteolytic cleavage to produce N-terminal and C-terminal fragments (NTF and CTF) which associate with each other to form functional heterodimer. Early studies about PS1 metabolism suggest that unknown cellular factors tightly regulate biogenesis of PS1 heterodimer. However, identity of these limiting factors as well as other members of gamma-secretase complex has remained elusive. Through biochemical and genetic approaches, recent discoveries of three essential proteins (Nct, PEN-2 and APH-1) for gamma-secretase activity, provide us candidates for those hypothesized factors. Indeed, three of them have been demonstrated to be components of high molecular weight gamma-secretase complex, while their precise functions are unclear. My preliminary results demonstrated the regulatory roles of PEN-2 and APH-1 in PS1 cleavage and Nct maturation. This proposal is designed to further investigate the biological functions of PEN-2 and APH-1 in regulating PS1/gamma-secretase complex formation via examining PEN-2 and APH-1 structure/function relationship (Specific Aim 1), their impact on protein trafficking (Specific Aim 2), as well as protein folding and intermolecular interactions (Specific Aim 3) of PS1 and Nct.

描述（由申请人提供）：编码早老素（PS1和PS2）的基因的基因突变是大多数早发家族性阿尔茨海默病（FAD）的原因。过去几年针对突变PS促进AD发病机制的广泛研究表明，PS1是γ-分泌酶复合物的关键组成部分，γ-分泌酶复合物是一种不寻常的蛋白酶，可催化淀粉样前体蛋白（APP）的膜内裂解并产生致病性小分子。肽阿贝塔。新生的全长 PS1 多肽经历内切蛋白水解裂解，产生 N 端和 C 端片段（NTF 和 CTF），这些片段彼此结合形成功能性异二聚体。关于 PS1 代谢的早期研究表明，未知的细胞因素严格调控 PS1 异二聚体的生物发生。然而，这些限制因素以及γ-分泌酶复合物的其他成员的身份仍然难以捉摸。通过生化和遗传学方法，最近发现了三种与γ-分泌酶活性相关的必需蛋白（Nct、PEN-2 和 APH-1），为我们提供了这些假设因素的候选蛋白。事实上，其中三种已被证明是高分子量γ-分泌酶复合物的组成部分，但它们的确切功能尚不清楚。我的初步结果证明了 PEN-2 和 APH-1 在 PS1 裂解和 Nct 成熟中的调节作用。本提案旨在通过检查PEN-2和APH-1结构/功能关系（具体目标1）以及它们对蛋白质的影响，进一步研究PEN-2和APH-1在调节PS1/γ分泌酶复合物形成中的生物学功能。 PS1 和 Nct 的运输（具体目标 2）以及蛋白质折叠和分子间相互作用（具体目标 3）。