Mechanisms of Sec61-Mediated Polytopic Protein Integration into the ER

Sec61 介导的多位蛋白整合至 ER 的机制

• 批准号: 7633397
• 负责人: BRIAN J CONTI
• 金额: $ 5.17万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7633397
• 关键词: Binding; Binding Proteins; Biochemical; Biogenesis; Complex; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Disease; Disease Attributes; Endoplasmic Reticulum; Ensure; Event; Goals; Integral Membrane Protein; Investigation; Lead; Lipid Bilayers; Measures; Mediating; Membrane; Membrane Proteins; Modeling; Mutation; One-Step dentin bonding system; Phase; Point Mutation; Proteins; Research; Ribosomes; Staging; Structure; Translating; aquaporin 4; design; extracellular; mutant; premature; prevent; protein folding; public health relevance

DESCRIPTION (provided by applicant): The long term goal of the proposed research is to define the precise mechanistic steps employed to ensure the structural maturation of multi-pass membrane proteins as they are synthesized by the ribosome and are integrated into the lipid bilayer. Relevance to disease is especially apparent in cystic fibrosis, which is caused by mutations in the polytopic protein CFTR, leading to its misfolding and, therefore, premature degradation. Intelligent design of disease treatment ultimately relies upon our ability to identify the biosynthetic event gone awry with disease-causing mutant proteins. Using a model polytopic protein, aquaporin 4 (AQP4), the current proposal determines the manner in which transmembrane segments move from the endoplasmic reticulum Sec61 translocon pore into the lipid bilayer, a fundamental phase during the biogenesis of polytopic proteins. Additionally, the functional organization of the translocon during distinct stages of AQP4 biogenesis will be defined using biochemical measures, namely by determining ribosome-translocon complex stability and composition at defined stages. These studies will, thereby, provide valuable information as to how the translocon proceeds step-wise to assemble functional polytopic proteins. PUBLIC HEALTH RELEVANCE One step in the creation of disease treatment is the investigation of how relevant protein mutations lead to the protein's malfunction. Cystic fibrosis is caused by mutations in a membrane bound protein that prevents its structural maturation into a functional protein. This research elucidates mechanisms by which membrane proteins acquire full structural maturation, thereby, providing a framework to examine disease-related mutations in membrane bound proteins.

描述（由申请人提供）：拟议研究的长期目标是确定用于确保由核糖体合成并整合到脂质双分子层的多通道膜蛋白结构成熟的精确机制步骤。与疾病的相关性在囊性纤维化中尤为明显，这是由多位点蛋白CFTR的突变引起的，导致其错误折叠并因此过早降解。疾病治疗的智能设计最终依赖于我们识别致病突变蛋白出错的生物合成事件的能力。利用模型多面体蛋白水通道蛋白4 (AQP4)，目前的建议确定了跨膜片段从内质网Sec61易位孔进入脂质双分子层的方式，这是多面体蛋白生物发生的一个基本阶段。此外，在AQP4生物发生的不同阶段，易位子的功能组织将通过生化测量来确定，即通过确定核糖体-易位子复合物在特定阶段的稳定性和组成。因此，这些研究将提供有价值的信息，以了解易位子如何逐步组装功能性多聚体蛋白。研究相关蛋白质突变如何导致蛋白质功能障碍是创造疾病治疗的一个步骤。囊性纤维化是由膜结合蛋白的突变引起的，这种突变阻止了其结构成熟为功能蛋白。本研究阐明了膜蛋白获得完全结构成熟的机制，从而为研究膜结合蛋白的疾病相关突变提供了一个框架。