Quality Control: Selective Degradation From the ER/Golgi

质量控制：内质网/高尔基体的选择性降解

• 批准号: 6898731
• 负责人: ANTONY A COOPER
• 金额: $ 25.78万
• 依托单位: UNIVERSITY OF MISSOURI KANSAS CITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6898731
• 关键词: Golgi apparatus; SDS polyacrylamide gel electrophoresis; Saccharomyces cerevisiae; endoplasmic reticulum; flow cytometry; green fluorescent proteins; membrane proteins; microarray technology; molecular chaperones; molecular cloning; proteasome; protein degradation; protein folding; ubiquitin

DESCRIPTION (provided by applicant): Soluble and membrane proteins of the secretory pathway enter the ER where they fold, are modified by carbohydrate addition and disulfide bond formation and assemble into complexes. Before exiting the ER, proteins must pass a quality control (ERQC) test. ERQC encompasses all those processes that ensure that only correctly folded/modified/assembled proteins exit the ER and includes retention in the ER, retrieval from downstream organelles and ER-associated degradation. ERQC contributes to the manifestation of disease either by depleting cells of essential proteins or by the toxic accumulation/aggregation of aberrant proteins. A progressive decline of ERQC in ageing highly differentiated neurons may play a major role in the neurodegenerative diseases such as Parkinson, Alzheimer's, Huntington's and prion diseases, all of which involve protein aggregation as the underlying pathology. The overall goal of this research is to understand the process of ERQC by defining the molecular components involved and determining how ERQC components function to recognize, retain, and retro-translocate misfolded substrates to be ubquitinated and degraded by the proteasome. The proposed project has four specific aims directed toward this goal. (1) The components of ERQC will be identified through a characterization of previously isolated ERQC mutants obtained at the end of the last grant period and through a genome wide mutant screen, synthetic genetic array analysis, synthetic lethal screen and micro array analysis to identify new components. (2) The role of ER to Golgi trafficking in ERQC will be examined through the use of retrograde trafficking mutants, cross-linking to Erv29p (a cargo receptor for ER exit) and determining the impact that glycosylation in the Golgi has on the degradation of ERQC substrates. (3) The aggregation of misfolded ERQC substrates in the ER results in their accumulation and associated cytotoxic effects. This specific aim is designed to identify ERQC substrate proteins that misfold and aggregate in the ER for use as a disease model in examining how cells contend with these potentially lethal accumulations. (4) A model substrate will assist in determining how soluble and polytopic membrane protein is treated differently by the ERQC. Knowledge and insights gained from these aims will lead to an understanding of the process of ERQC to be used to interpret protein aggregation based diseases.

描述（由申请人提供）：分泌途径的可溶性和膜蛋白进入它们折叠的ER，通过碳水化合物添加和二硫键键形成修改，并组装成复合物。在退出ER之前，蛋白质必须通过质量控制（ERQC）测试。 ERQC包含所有这些过程，这些过程仅正确折叠/修改/组装的蛋白会退出ER并包括在ER中保留，从下游细胞器中检索并与ER相关的降解。 ERQC通过耗尽必需蛋白质的细胞或异常蛋白质的有毒积累/聚集来促进疾病的表现。 ERQC在衰老高度分化的神经元中的逐渐下降可能在神经退行性疾病中起主要作用，例如帕金森氏症，阿尔茨海默氏症，亨廷顿和王室疾病，所有这些疾病都涉及蛋白质聚集作为潜在的病理学。这项研究的总体目标是通过定义所涉及的分子成分并确定ERQC组件如何了解ERQC的过程 识别，保留和恢复过渡的错误折叠底物的功能是被蛋白酶体降解和降解的。拟议的项目具有针对这一目标的四个特定目标。 （1）ERQC的组成部分将通过在上一个赠款期结束时获得的先前分离的ERQC突变体的表征以及通过基因组宽突变体筛选，合成遗传阵列分析，合成致死筛查和微阵列分析以识别新组件。 （2）将通过使用逆行运输突变体，与ERV29P的交联（用于ER出口的货物受体）的ER对ERQC的作用，并确定高尔基体在ERQC substrates脱位的影响。 （3）ER中错误折叠的ERQC底物的聚集导致其积累和相关的细胞毒性作用。该特定目的旨在识别ERQC底物蛋白质，这些蛋白质在ER中折叠和骨料构成，以用作疾病模型，以研究细胞如何与这些潜在的致命积累抗衡。 （4）模型底物将有助于确定可溶性和多重膜蛋白如何通过ERQC不同处理。从这些目标中获得的知识和见解将导致对ERQC过程的理解，以解释基于蛋白质的疾病。