CFTR Processing in the Endoplasmic Reticulum

内质网中的 CFTR 处理

• 批准号: 7535581
• 负责人: JOHN R RIORDAN
• 金额: $ 35.76万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-30 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7535581
• 关键词: ATP phosphohydrolase; Address; Amyloid; Area; Binding; Biochemical; Biological Assay; Calnexin; Categories; Cell membrane; Cell surface; Cells; Chloride Channels; Code; Complex; Coupling; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Development; Disease; Due Process; Employee Strikes; Endoplasmic Reticulum; Environment; Event; Foundations; Genes; Hereditary Disease; Integral Membrane Protein; Ion Channel; Joints; Knowledge; Laboratories; Learning; Link; Maps; Membrane; Membrane Protein Traffic; Methods; Modification; Molecular; Molecular Chaperones; Molecular Conformation; Movement; Mutation; Nucleotides; Other Genetics; Pathway interactions; Physiological; Process; Property; Protein Export Pathway; Proteins; Proteomics; Public Health; Research Personnel; Role; Side; Structure; Surface; System; Temperature; Testing; Tissues; Vesicle; Work; base; chaperone machinery; cystic fibrosis patients; experience; insight; loss of function; member; mutant; novel; novel therapeutic intervention; polypeptide; prevent; programs; protein folding; protein misfolding; protein structure; prototype; research study; response; skills; temperature sensitive mutant; tool; trafficking

Protein misfolding is at the basis of many disease processes, due either to the loss of function of the misfolded protein or cell and tissue damage caused by accumulation of aberrant protein structures(eg. amyloid). Cystic fibrosis (CF), in which the most common mutation (AF508 ) in the CFTR chloride channel gene prevents normal conformational maturation and trafficking from the endoplasmic reticulum (ER) to the cell surface, has become a prototype for the loss of function category of folding disease. The AF508 mutation is temperature sensitive and the mutant protein is active when induced to traffic at permissive temperature or by other means. However, the molecular events in the assembly of the wild-type multidomain CFTR protein and the cellular recognition mechanisms that distinguish the mutant from the wild-type remain unknown. Through integration of our skills in CFTR structure/function (Riordan) and protein folding and trafficking (Balch) we have have made considerable progress towards filling these knowledge gaps by developing new experimental tools for study of the system, mapping of key domain interactions in CFTR assembly, discovery of an acidic ER export code that must be exposed for recognition by the COP II coat on budding ER vesicles and identification, by proteomic methods, of chaperone complexes on both sides of the ER membrane that contribute to the formation of a mature structure . Significantly, we have found that manipulations of the levels of cytoplasmic Hsp90 cochaperones strongly influence the nascent AF508 polypeptide. Reduction of the level of one member of this complex, Aha 1 results in substantial rescue of the mutant protein. Therefore our aims in the continuing work are 1) to elucidate the steps in normal CFTR domain assembly and their perturbation by AF508 and 2) to define the role of the chaperone environment in ER export of CFTR to enable AF508 export by manipulation of this environment. Our joint efforts will test the central hypothesis that the primary impact of the AF508 mutation is to prevent an explicit set of sequential domain assembly steps which rely on spatially and temporally ordered interactions with molecular chaperone and cochaperone complexes. Public Health Relevence- Learning how the assembly and movement of the CFTR ion channel to the cell membrane occurs and manipulation of the steps defective in CF patients will enable development of new therapeutic interventions and provide insight into other major folding diseases.

蛋白质错误折叠是在许多疾病过程的基础上，要么是由于功能的丧失 异常蛋白质结构的积累引起的错误折叠的蛋白质或细胞以及组织损伤（例如 淀粉样蛋白）。囊性纤维化（CF），其中CFTR氯化物通道中最常见的突变（AF508） 基因防止正常构象成熟和从内质网（ER）运输到 细胞表面已成为折叠疾病功能类别丧失的原型。 AF508 突变是温度敏感的，突变蛋白在允许时诱导流量时具有活性 温度或其他方式。但是，野生型多域组装中的分子事件 CFTR蛋白和区分突变体与野生型的细胞识别机制保持 未知。通过整合我们在CFTR结构/功能（Riordan）和蛋白质折叠的技能和 贩运（Balch）我们已经取得了很大的进步来填补这些知识差距 开发用于研究系统研究的新实验工具，CFTR中关键域相互作用的映射 组装，发现必须暴露于COP II涂层识别的酸性ER导出代码 通过蛋白质组学方法萌芽的Er囊泡和鉴定在该伴侣的两侧的伴侣复合物 ER膜有助于形成成熟的结构。重要的是，我们发现 对细胞质HSP90联合酮水平的操纵强烈影响新生AF508 多肽。降低了该建筑群的一个成员的水平，AHA 1导致大量营救 突变蛋白。因此，我们在继续工作中的目标是1）阐明正常CFTR中的步骤 域组件及其在AF508和2）定义伴侣环境在 CFTR的ER导出以通过操纵这种环境启用AF508出口。我们的联合努力将测试 中心假设，即AF508突变的主要影响是防止一组明确的顺序 域组装步骤依赖于空间和时间有序的与分子伴侣的相互作用 和联合酮配合物。公共卫生相关性 - 学习如何组装和运动 发生通往细胞膜的CFTR离子通道发生，CF患者中缺陷的步骤操纵将 能够开发新的治疗干预措施，并洞悉其他主要折叠疾病。