BIOCHEMISTRY OF UBIQUITIN-CONJUGATING ENZYMES

泛素结合酶的生物化学

• 批准号: 6701307
• 负责人: VINCENT CHAU
• 金额: $ 32.01万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6701307
• 关键词: endoplasmic reticulum; enzyme mechanism; enzyme model; enzyme substrate; human genetic material tag; ligase; membrane activity; myosins; protein degradation; protein localization; proteolysis; tissue /cell culture; ubiquitin

DESCRIPTION (adapted from applicant's abstract): ER-associated degradation refers to the process whereby membrane as well as lumenal proteins in the endoplasmic reticulum (ER) compartment are degraded by the cytosolic 26S proteasome. Proteins that are routed into this degradative pathway include proteins whose levels are subjected to regulated proteolysis as well as newly synthesized proteins that entered the ER but failed either to fold properly or to be assembled with their constituent protein partners. In several human hereditary diseases, extensive degradation of specific allelic variants results in the reduction or absence of such proteins in their destined compartment, leading to deficiency in function and disease symptoms. Examples of such allelic variants have been found with the CFTR protein in cystic fibrosis, alpha1-antitrypsin in childhood liver disease and adult emphysema, insulin receptor in type A insulin resistance, LDL receptor in familial hypercholesterolemia and in myeloperoxidase deficiency. While the role of ubiquitin-mediated proteolysis in the degradation of ER-associated proteins is well recognized, virtually nothing is known on the ubiquitination process of this pathway in mammalian cells. Such information is crucial to understand how the pathway could be regulated and to evaluate the potential of this pathway for therapeutic intervention. The principal investigator proposes here that ER-associated degradation in mammalian cells utilizes a similar cascade of reactions as in the yeast Saccharomyces cerevisiae, for which the identity of several protein participants of the ubiquitination process have been identified by genetic analysis. The goal will be to test this hypothesis with a model substrate system that offers the significant advantage of being amenable to biochemical analysis. To this end, the principal investigator has identified a set of human ubiquitin-conjugating enzymes and ubiquitin-protein ligases that are likely participants in this pathway. He expects that the biochemical analysis will provide important mechanistic insights and the prerequisite information for the evaluation of this pathway for potential therapeutic intervention.

描述（改编自申请人的摘要）：ER 相关降解 指膜和腔内蛋白质在细胞内的过程 内质网 (ER) 区室被胞质 26S 降解 蛋白酶体。进入该降解途径的蛋白质包括 其水平受到调节的蛋白水解以及新的蛋白质 合成的蛋白质进入内质网但未能正确折叠或 与其组成蛋白伙伴组装。在几个人类 遗传性疾病，特定等位基因变异的广泛降解结果 在其预定区室中此类蛋白质减少或缺失的情况下， 导致功能缺陷和疾病症状。此类的例子 在囊性纤维化中发现了 CFTR 蛋白的等位基因变异， α1-抗胰蛋白酶在儿童肝病和成人肺气肿中的作用，胰岛素 A 型胰岛素抵抗受体、家族性 LDL 受体 高胆固醇血症和髓过氧化物酶缺乏症。 而泛素介导的蛋白水解作用在降解中的作用 ER 相关蛋白已被广泛认可，但实际上对此一无所知。 该途径在哺乳动物细胞中的泛素化过程。此类信息是 对于了解如何调节该途径并评估该途径至关重要 该途径用于治疗干预的潜力。校长 研究人员在此提出，哺乳动物细胞中与 ER 相关的降解 利用与酵母菌类似的级联反应 酿酒酵母，其中几个蛋白质参与者的身份 泛素化过程已通过遗传分析确定。目标将 是用一个模型基底系统来测试这个假设，该系统提供了 易于生化分析的显着优势。为此， 主要研究人员已经确定了一组人类泛素缀合 酶和泛素蛋白连接酶可能参与这一过程 途径。他预计生化分析将提供重要的信息 机制见解和评估的先决条件信息 这条潜在治疗干预的途径。