Roles of Cholesterol and Membrane Nanodomains in the Amyloidogenic Pathway

胆固醇和膜纳米结构域在淀粉样蛋白生成途径中的作用

• 批准号: 9333750
• 负责人: Anne K Kenworthy
• 金额: $ 360.44万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9333750
• 关键词: Abeta synthesis; Alzheimer' s Disease; American; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Binding; Biological; C-terminal; Cell membrane; Cells; Cholesterol; Cleaved cell; Clupeidae; Complex; Coupled; Development; Disease; Environment; Enzymes; Etiology; Future; G-substrate; Length; Lipids; Literature; Measurement; Membrane; Membrane Fluidity; Membrane Microdomains; Membrane Proteins; Modeling; Molecular; Molecular Conformation; Monitor; Neurons; Pathway interactions; Pharmacology; Phase; Plasma; Play; Production; Property; Protein Dynamics; Proteins; Research; Role; Structure; Testing; Therapeutic; Vesicle; Work; amyloid formation; base; beta secretase; biophysical analysis; experimental study; gamma secretase; insight; membrane model; polypeptide; preference; protein structure; segregation; three dimensional structure; tool

Project Summary Roles of Cholesterol and Membrane Nanodomains in the Amyloidogenic Pathway Cholesterol is thought to play a key regulatory role in the formation of the amyloid-β polypeptide (Aβ) via the amyloidogenic pathway in which the full length amyloid precursor protein is cleaved by β-secretase to release is transmembrane 99 residue C-terminal domain (C99). C99 is then cleaved by γ-secretase to release Aβ. Membrane cholesterol appears to promote the amyloidogenic pathway, with much evidence pointing to a mechanism involving cholesterol-enriched regions of the plasma membrane often referred to as lipid rafts. According to this model, cholesterol promotes partitioning both of APP and C99 into lipid rafts, which are enriched in β-secretase and γ-secretase, thereby activating amyloidogenic cleavage. Rafts are therefore proposed to spatially segregate the amyloidogenic pathway from the bulk membrane phase. However, much of the evidence in support of this model is indirect. It is the premise of this work that it is important to test this model which, if correct, suggests a strategy for reducing Aβ formation by reducing raft partitioning of APP/C99. On the other hand, if the model is incorrect, the existing literature supporting this model may need to be re- assessed and the pursuit of therapeutic strategies based on this model would possibly need to be viewed as a red herring. A sub-premise of this work is that it is critical to conduct studies of the biophysical and structural biological basis for partitioning of C99/APP between raft and non-raft phases. These studies will provide fundamental insight how major changes in membrane phase properties impact membrane protein structure and localization. Moreover, a molecular understanding of the basis for the phase partitioning preferences of APP and C99 may inspire rational pharmacological strategies for altering the phase preferences of these molecules for the purpose of reducing Aβ formation. We note that in order to maintain an appropriate (feasible!) scope for the studies to be carried out, we will focus on γ-secretase and C99. Studies of full length APP and β-secretase represent a future direction for this work after the completion of the aims below. Aim 1. Test the hypothesis that C99 and γ-secretase preferentially localize to membrane raft domains. Aim 2. Test the hypothesis that raft-association alters the structure of C99. Aim 3. Determine how the cleavage of C99 by γ-secretase is modulated by membrane partitioning, membrane fluidity, C99 structure, and C99-cholesterol complex formation.

项目摘要 胆固醇和膜纳米结构域在淀粉样蛋白生成途径中的作用 胆固醇被认为在淀粉样蛋白-β 多肽 (Aβ) 的形成中发挥着关键的调节作用 淀粉样蛋白生成途径，其中全长淀粉样前体蛋白被 β-分泌酶裂解并释放 是跨膜 99 残基 C 端结构域 (C99)，然后被 γ 分泌酶切割以释放 Aβ。 膜胆固醇似乎促进淀粉样蛋白生成途径，许多证据表明 该机制涉及质膜上富含胆固醇的区域，通常称为脂筏。 根据该模型，胆固醇促进 APP 和 C99 分成脂筏，即 富含β-分泌酶和γ-分泌酶，从而激活淀粉样蛋白筏的裂解。 提出将淀粉样蛋白生成途径与本体膜相空间分离。 支持该模型的证据是间接的，这是这项工作的前提，测试这一点很重要。 该模型如果正确，则提出了一种通过减少 APP/C99 筏分配来减少 Aβ 形成的策略。 另一方面，如果模型不正确，支持该模型的现有文献可能需要重新修改 评估和基于该模型的治疗策略的追求可能需要被视为 这项工作的一个子前提是进行生物物理和结构研究至关重要。 这些研究将提供 C99/APP 在筏相和非筏相之间分配的生物学基础。 膜相特性的主要变化如何影响膜蛋白结构的基本见解 此外，对相分配偏好基础的分子理解。 APP 和 C99 可能会激发合理的药理学策略来改变这些物质的相偏好 我们注意到，为了保持适当的Aβ形成。 （可行！）对于要进行的研究范围，我们将重点关注γ-分泌酶和C99的全长研究。 APP和β-分泌酶代表了完成以下目标后这项工作的未来方向。 目标 1. 检验 C99 和 γ-分泌酶优先定位于膜筏结构域的假设。 目标 2. 检验筏缔合改变 C99 结构的假设。 目标 3. 确定膜分配如何调节 γ-分泌酶对 C99 的裂解， 膜流动性、C99 结构和 C99-胆固醇复合物形成。

项目成果

Lipid peroxidation drives liquid-liquid phase separation and disrupts raft protein partitioning in biological membranes.

脂质过氧化驱动液-液相分离并破坏生物膜中的筏蛋白分配。

• 发表时间: 2023-09-14
• 作者: Balakrishnan, Muthuraj;Kenworthy, Anne K
• 通讯作者: Kenworthy, Anne K

Reciprocal modulation between amyloid precursor protein and synaptic membrane cholesterol revealed by live cell imaging.

活细胞成像揭示淀粉样前体蛋白和突触膜胆固醇之间的相互调节。

• 发表时间: 2019
• 影响因子: 6.1
• 作者: DelBove, Claire E;Strothman, Claire E;Lazarenko, Roman M;Huang, Hui;Sanders, Charles R;Zhang, Qi
• 通讯作者: Zhang, Qi

Lipid Peroxidation Drives Liquid-Liquid Phase Separation and Disrupts Raft Protein Partitioning in Biological Membranes.

脂质过氧化驱动液-液相分离并破坏生物膜中的筏蛋白分配。

• 发表时间: 2024-01-17
• 影响因子: 15
• 作者: Balakrishnan, Muthuraj;Kenworthy, Anne K
• 通讯作者: Kenworthy, Anne K