Structure, Folding, and Misfolding of PMP22

项目摘要 编码外周髓鞘蛋白22（PMP 22）的基因中的遗传显性突变 导致其序列中单个氨基酸的变化，从而导致髓鞘缺陷， 常见的人类周围神经病，Charcot-Marie-Tooth病IA型（CMTD）。是 认为CMTD突变导致分泌途径早期的PMP 22错误装配， 导致蛋白质功能的丧失以及潜在的细胞毒性 集料.本项目的总体目标是阐明 CMTD相关突变对蛋白质的结构、稳定性和折叠的干扰 这个关键的膜蛋白。我们还试图测试化学伴侣是否可以纠正 通常在PMP 22的CMTD突变体形式中观察到的折叠缺陷。 目标1.表征野生型（WT）和CMTD突变体形式的结构， 使用NMR光谱法测定人PMP 22。目的1将检验CMTD突变体 PMP 22的形式在构象和/或寡聚状态方面不同于WT蛋白。 结构信息还将阐明PMP 22的结构/功能关系及其在以下方面的作用： 髓鞘的生产和维护，并将提供生物物理学的见解如何氨基酸 突变导致CMTD。PMP 22结构的确定也将增加目前的 稀疏的人类膜蛋白结构的画廊。 目标2.表征WT和CMTD突变体形式的稳定性和折叠动力学， PMP22。目的2将检验疾病相关的PMP 22突变使细胞不稳定的假设。 蛋白目的2还将检验疾病相关的突变形式的PMP 22折叠的假设。 比野生型蛋白质更慢和/或效率更低。我们还将测试CMTD是否 PMP 22的突变形式易于聚集。 目标3。确定化学伴侣是否可以增加细胞表面表达 CMTD突变体形式的PMP 22。目的3将检验PMP 22类似于其他药物的假设。 与涉及蛋白质错误组装的疾病相关的人膜蛋白， 它已经建立，正确的折叠和贩运可以恢复使用 化学伴侣

Project Summary 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.