Structure, Folding, and Misfolding of PMP22

PMP22 的结构、折叠和错误折叠

• 批准号: 8039908
• 负责人: Bruce D Carter
• 金额: $ 30.53万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8039908
• 关键词: Afferent Neurons; Amino Acids; Biological; Cell Line; Cell surface; Cells; Charcot-Marie-Tooth Disease; Chemicals; Coculture Techniques; Defect; Disease; Genes; Goals; Human; Human Cell Line; Kinetics; Lead; Link; Maintenance; Membrane Proteins; Modeling; Molecular; Molecular Chaperones; Molecular Conformation; Mutation; Myelin; Myelin Proteins; NMR Spectroscopy; Nature; Pathway interactions; Peripheral; Peripheral Nervous System Diseases; Production; Proteins; Research; Role; Schwann Cells; Structure; Structure-Activity Relationship; Testing; Transgenic Mice; Work; base; cytotoxic; human PMP22 protein; human disease; insight; mouse model; mutant; novel therapeutics; overexpression; protein function; protein structure; public health relevance; trafficking

DESCRIPTION (provided by applicant): Genetically dominant mutations in the gene that encodes peripheral myelin protein 22 (PMP22) lead to single amino acid changes in its sequence that result in defective myelin, underlying the common human peripheral neuropathy, Charcot-Marie-Tooth Disease Type IA (CMTD). It is believed that CMTD mutations result in misassembly of PMP22 early in the secretory pathway, resulting in the loss of protein function and also in the formation of potentially cytotoxic aggregates. The overall goal of this project is to elucidate the molecular biophysical nature of the perturbations made by CMTD-associated mutations to the structure, stability and folding of this critical membrane protein. We also seek to test whether chemical chaperones can correct the folding defects normally observed for CMTD mutant forms of PMP22. Aim 1. Characterize the structures of the wild type (WT) and CMTD mutant forms of human PMP22 using NMR spectroscopy. Aim 1 will test the hypothesis that CMTD mutant forms of PMP22 differ from the WT protein in terms of conformation and/or oligomeric state. Structural information will also illuminate PMP22's structure/function relationships and its role in myelin production and maintenance, and will provide biophysical insight into how amino acid mutations result in CMTD. Determination of PMP22's structure will also add to the currently sparse gallery of human membrane protein structures. Aim 2. Characterize the stability and folding kinetics of WT and CMTD mutant forms of PMP22. Aim 2 will test the hypothesis that disease-related mutations of PMP22 destabilize the protein. Aim 2 will also test the hypothesis that disease-related mutant forms of PMP22 fold more slowly and/or inefficiently than the wild type protein. We will also test whether CMTD mutant forms of PMP22 are aggregation-prone. Aim 3. Determine whether chemical chaperones can increase the cell surface expression of CMTD mutant forms of PMP22. Aim 3 will test the hypothesis that PMP22 is akin to other human membrane proteins that are linked to diseases involving protein misassembly and for which it has already been established that proper folding and trafficking can be restored using chemical chaperones. PUBLIC HEALTH RELEVANCE: Studies of the structure, folding, and stability of the human peripheral myelin protein 22 (PMP22) will be undertaken to unravel the molecular basis for Charcot-Marie Tooth Disease, a peripheral neuropathy. Results from this work are expected to contribute to novel therapeutic strategies for this human disease.

描述（由申请人提供）：编码外周髓磷脂蛋白 22 (PMP22) 的基因中的遗传显性突变导致其序列中的单个氨基酸变化，从而导致髓磷脂缺陷，从而导致常见的人类周围神经病夏科-马里-图思病IA 型（CMTD）。据认为，CMTD 突变导致 PMP22 在分泌途径早期错误组装，导致蛋白质功能丧失，并形成潜在的细胞毒性聚集体。该项目的总体目标是阐明 CMTD 相关突变对这一关键膜蛋白的结构、稳定性和折叠造成的扰动的分子生物物理性质。我们还试图测试化学伴侣是否可以纠正通常在 PMP22 的 CMTD 突变形式中观察到的折叠缺陷。目标 1. 使用 NMR 光谱表征人 PMP22 野生型 (WT) 和 CMTD 突变体形式的结构。目标 1 将检验以下假设：PMP22 的 CMTD 突变形式在构象和/或寡聚状态方面与 WT 蛋白不同。结构信息还将阐明 PMP22 的结构/功能关系及其在髓磷脂生成和维持中的作用，并将提供有关氨基酸突变如何导致 CMTD 的生物物理学见解。 PMP22 结构的确定也将丰富目前稀疏的人类膜蛋白结构库。目标 2. 表征 PMP22 的 WT 和 CMTD 突变体形式的稳定性和折叠动力学。目标 2 将检验以下假设：PMP22 的疾病相关突变会破坏该蛋白质的稳定性。目标 2 还将检验以下假设：与野生型蛋白相比，与疾病相关的 PMP22 突变形式折叠得更慢和/或效率更低。我们还将测试 PMP22 的 CMTD 突变形式是否易于聚集。目标 3. 确定化学伴侣是否可以增加 PMP22 CMTD 突变形式的细胞表面表达。目标 3 将检验以下假设：PMP22 类似于其他人类膜蛋白，这些蛋白与涉及蛋白质错误组装的疾病有关，并且已经确定可以使用化学伴侣来恢复正确的折叠和运输。 公共健康相关性：将对人外周髓鞘蛋白 22 (PMP22) 的结构、折叠和稳定性进行研究，以揭示腓骨肌萎缩症（一种周围神经病）的分子基础。这项工作的结果预计将为这种人类疾病的新治疗策略做出贡献。