Functions of Ub-like Proteins & Processing Proteases

Ub 样蛋白的功能

• 批准号: 6785957
• 负责人: KEITH D WILKINSON
• 金额: $ 30.4万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6785957
• 关键词: chemical conjugate; chemical synthesis; endopeptidases; enzyme mechanism; enzyme substrate; protease inhibitor; protein structure function; proteomics; ubiquitin

DESCRIPTION (provided by applicant): Deubiquitinating enzymes (DUBs, also known as deconjugating enzymes) are important regulatory proteases that process the primary gene products of the ubiquitin gene family, reverse the conjugation of ubiquitin to cellular proteins, and disassemble the polyubiquitin chains that target proteins for degradation by the proteasome. As such, they regulate proteolysis and thereby progression through the cell cycle, signal transduction pathways, the stress response, antigen presentation, chromatin structure, receptor internalization and endocytosis. It has only recently been appreciated that modification of proteins by other ubiquitin-like (Ubl) proteins exerts a similar targeting function. The underlying assumption of this grant is that regulation of the Ubl pathways by deconjugation of ubiquitin-like proteins is likely to be equally important, with roles in cancer, the regulation of growth and apoptosis. The enzymes that reverse the conjugation of UbI proteins (Ubiquitin-like protein proteases, ULP) are attractive targets for further study since the reversal of these modifications is expected to interfere with functions. As they are proteases, a large body of work suggests approaches to effective pharmacological intervention. Additionally, it is easier (conceptually and practically) to interfere with these pathways by overexpressing a deconjugating enzyme than it is to prevent attachment of the UbI domain; an approach that requires gene knock-out or dominant negative approaches. Understanding the role of these deconjugating enzymes requires that we know more about this class of enzymes, their substrates and their regulation. A series of inhibitors and substrates for ULPs will be synthesized and used to test three specific hypotheses. First, Dr. Wilkinson will test the hypothesis that an integral subunit of the mammalian COP9-signalosome is able to reverse the Nedd8 modification of cullins. He also will test the hypothesis that modification of proteins by ISG15 are an integral part of the interferon response by identifying, and interfering with the function of, enzymes which reverse this modification. He will determine if conjugation of the proapoptotic Ubl FAT10 is reversible. Finally, he will test the hypothesis that HAUSP and/or SENPI are the Ubl that removes SUMO-1 from the Promyelocytic leukemia protein, triggering the disassembly of PML.

描述（由申请人提供）：去泛素化酶（配音，也称为decon偶联酶）是重要的调节蛋白酶，可处理泛素基因家族的主要基因产物，将泛素蛋白与细胞蛋白的共轭相反，并通过蛋白质构成蛋白质的蛋白质，以供应蛋白质链蛋白。因此，它们调节蛋白水解，从而在细胞周期，信号转导途径，应力反应，抗原表现，染色质结构，受体内在化和内吞作用中进展。直到最近才理解，其他泛素样（UBL）蛋白质对蛋白质的修饰具有相似的靶向功能。该赠款的基本假设是，通过将泛素样蛋白的解偶构化来调节UBL途径，可能同样重要，在癌症中的作用，调节生长和凋亡。逆转UBI蛋白（泛素样蛋白质蛋白酶，ULP）的偶联的酶是进一步研究的有吸引力的靶标，因为这些修饰的逆转有望干扰功能。由于它们是蛋白酶，因此大量工作提出了有效的药理干预方法。此外，（从概念上和实际上）更容易通过过表达解体酶来干扰这些途径，而不是防止UBI域的附着。一种需要基因敲除或主要负面方法的方法。了解这些解偶酶的作用要求我们更多地了解这类酶，它们的底物及其调节。将合成一系列的ULP抑制剂和底物，并用于检验三个特定的假设。首先，威尔金森博士将检验以下假设：哺乳动物COP9-信号体的整体亚基能够逆转库林蛋白的NEDD8修饰。他还将检验以下假设：ISG15对蛋白质的修饰是干扰素反应的组成部分，通过识别和干扰酶的酶的功能，这些酶反向这种修饰。他将确定促凋亡的UBL Fat10的结合是否可逆。最后，他将检验以下假设：Hausp和/或Senpi是从Promyelocytic Leukemia蛋白中去除SUMO-1的UBL，从而触发了PML的拆卸。