Deciphering the Molecular Features Underlying LRP1-Mediated Tau Spread

几种神经退行性疾病，如阿尔茨海默病（AD），其特征在于扩散和 蛋白质tau的聚集。最近，我们发现了一种细胞受体，LRP 1（低密度脂蛋白 受体相关蛋白1），调节tau扩散途径。LRP 1的敲除防止tau扩散 在人类iPS神经元和小鼠大脑中，这表明tau-LRP 1相互作用可能是一个重要的机制。 疾病干预的切入点。不幸的是，对tau-LRP 1分子复合物的详细了解 仍然缺乏。因此，本项目的主要目标是确定tau-LRP 1结构界面， 辨别tau结构的翻译后修饰（PTM）如何影响tau的摄取和传播。在 在初步工作中，我们已经开发了纯化和测量tau和LRP 1之间相互作用的方案。我们 已经建立了细胞平台来模拟tau蛋白的传播， 通过tau PTM。为了充分开展这项工作，我们提出三个目标。在目标1中，我们将使用TR-FRET来建立 tau蛋白和LRP 1之间的体外亲和力和质谱分析来绘制蛋白质-蛋白质界面。在目标2中， 我将研究tau蛋白磷酸化如何影响tau-LRP 1复合物，以及这对tau蛋白扩散有什么影响 和聚合。在目标3中，我们将关注改变赖氨酸残基的tau PTM。我们将评估泛素化 或乙酰化可以影响tau-LRP 1相互作用，如果它们影响tau聚集，如果它们促进或抑制 细胞中的tau摄取和接种。创新的实验方法和全面的分析概述 本文将提供重要机制见解，并发展我们对致病性tau蛋白调节的理解， AD.这将是开发和评估潜在AD治疗方法的重要的第一步。

Several neurodegenerative diseases, such as Alzheimer’s disease (AD), are characterized by the spread and aggregation of the protein tau. Recently, we identified a cellular receptor, LRP1 (Low-density lipoprotein Receptor-related Protein 1), that regulates the tau spread pathway. Knockdown of LRP1 prevents tau spread in human iPS neurons and the mouse brain, suggesting that the tau-LRP1 interaction could be an important entry point for disease intervention. Unfortunately, a detailed understanding of the tau-LRP1 molecular complex is still lacking. Therefore, the main objective of this project is to define the tau-LRP1 structural interface and discern how post-translation modifications (PTMs) to tau’s structure influence tau uptake and spread. In preliminary work, we have developed protocols to purify and measure interactions between tau and LRP1. We have established cellular platforms to model tau propagation and have shown that this process can be influenced by tau PTMs. To fully develop this work, we propose three aims. In Aim 1, we will use TR-FRET to establish in vitro affinities between tau and LRP1 and mass spectrometry to map the protein-protein interface. In Aim 2, we will look at how tau phosphorylation can influence the tau-LRP1 complex and what effect this has on tau spread and aggregation. In Aim 3, we will focus on tau PTMs that alter lysine residues. We will assess if ubiquitination or acetylation can impact the tau-LRP1 interaction, if they influence tau aggregation, and if they promote or inhibit tau uptake and seeding in cells. The innovative experimental methods and comprehensive analyses outlined herein will provide important mechanistic insight and develop our understanding of pathogenic tau regulation in AD. This will be an essential first step forward for the development and evaluation of potential AD therapeutics.