Regulation of the ubiquitin-proteasome-system during oxidative stress

氧化应激过程中泛素蛋白酶体系统的调节

• 批准号: 5249904
• 负责人: Professor Dr. Tilman Grune
• 金额: --
• 依托单位: Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke (DIfE)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2000
• 资助国家: 德国
• 起止时间: 1999-12-31 至 2005-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5249904?language=en
• 关键词: Regulation; ubiquitin; proteasome; system; during

Many environmental toxicants, medical drugs, and abuse substances exert their toxic effects via oxygen free radicals and related active oxygen species. Despite extensive work on lipid peroxidation little is known about protein oxidation and the possible regulation of proteolytic enzymes, responsible for degradation of these oxidized proteins. Our objective is to test the regulation of the proteasomal system and the interaction of oxidized proteins with the ubiquitination system.Although it seems to be established, that the proteasomal system degrades oxidized cytosolic proteins, the mechanism of recognition by the ubiquitin system is still not known. It was found by several groups that the 20S proteasome can recognize oxidized proteins and degrade them preferentially in in vitro systems. On the other hand in living cells the major protease degrading intracellular proteins is the 26S proteasome. Since this proteasomal form is able to recognize and degrade polyubiquitinated proteins it is interesting to know the recognition signals of oxidized proteins by the ubiquitination system. Therefore, oxidized proteins and model substrates will be used as substrates for ubiquitination assays and by using of oxidation markers the selective recognition is investigated. It was demonstrated, that besides the possible interactions of the ubiquitinating enzymes with the substrate a modulation of the proteasome itself occurs during oxidative stress. The binding of the major regulators, like the 11S and the 19S particles to the 20S core proteasome will be investigated during and after oxidative stress together with other regulatory mechanisms of the proteasome. Therefore, the proposal is focused on the function and regulation of the proteasomal and the ubiquitination system of mammalian cells and seems to fulfill the criteria of the program "Structure, function and regulation of the 20S/26S ubiquitin-proteasome system".

许多环境毒物、医疗药物和滥用物质通过氧自由基和相关活性氧发挥毒性作用。尽管对脂质过氧化进行了大量研究，但人们对蛋白质氧化和负责降解这些氧化蛋白质的蛋白水解酶的可能调节知之甚少。我们的目的是测试蛋白酶体系统的调节以及氧化蛋白与泛素化系统的相互作用。虽然蛋白酶体系统降解氧化胞质蛋白似乎已成立，但泛素系统识别的机制仍不清楚。多个研究小组发现20S蛋白酶体可以识别氧化蛋白质并在体外系统中优先降解它们。另一方面，在活细胞中，降解细胞内蛋白质的主要蛋白酶是 26S 蛋白酶体。由于这种蛋白酶体形式能够识别和降解多聚泛素化蛋白质，因此了解泛素化系统对氧化蛋白质的识别信号很有趣。因此，氧化蛋白质和模型底物将用作泛素化测定的底物，并通过使用氧化标记来研究选择性识别。结果表明，除了泛素化酶与底物可能存在的相互作用外，氧化应激期间还会发生蛋白酶体本身的调节。主要调节因子（如 11S 和 19S 颗粒）与 20S 核心蛋白酶体的结合将在氧化应激期间和之后与蛋白酶体的其他调节机制一起进行研究。因此，该提案的重点是哺乳动物细胞的蛋白酶体和泛素化系统的功能和调节，似乎满足“20S/26S泛素-蛋白酶体系统的结构、功能和调节”项目的标准。