Molecular Basis of RING E3 Ligase Pirh2 and HECT E3 Ligase Itch Interaction.

RING E3 连接酶 Pirh2 和 HECT E3 连接酶 Itch 相互作用的分子基础。

• 批准号: RGPIN-2017-06582
• 负责人: Leng, Roger
• 金额: $ 2.04万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657205
• 关键词: Molecular; Basis; RING; E3; Ligase

Proteins are one of the most important group of molecules in the human body. Regulation of protein stability and turnover is a key task in the cell. The majority of proteins are degraded by the ubiquitin (Ub)-proteasome pathway (UPP). The UPP affects a wide variety of cellular processes and substrates and defects in the UPP can result in the pathogenesis of human diseases. The central role of the UPP in biology has been recognized with the Nobel Prize for Chemistry in 2004. Ubiquitin-mediated protein degradation is a three-step process involving three enzymes: E1 (Ub-activating enzyme), E2 (Ub-conjugating enzyme), and E3 (Ub protein ligase). A new class of ubiquitination enzyme, E4 (a Ub chain assembly factor), was recently shown to be necessary for the degradation of some proteins via the ubiquitin fusion degradation pathway. Together, these enzymes catalyze the covalent attachment of one or more ubiquitin moieties to protein lysine residues. E3 enzymes play a central role in the recognition and ubiquitination of substrates and fall into three subgroups: (i) HECT domain ligases such as E6-APand Itch; (ii) RING domain ligases, including Pirh2 and Mdm2; and (iii) U-box domain ligases representing a non-canonical RING domain such as UFD2 and CHIP (carboxyl terminus of Hsp70-interacting protein). The ubiquitinated proteins are subsequently targeted for degradation by the 26S proteasome.******Our laboratory is studying the regulation and function in the body of two molecules known as Pirh2 and Itch that may be able to regulate cell growth. The two molecules belong to the E3 ligase family, which promote protein degradation. We previously demonstrated that Pirh2 can negatively regulate Itch activities and functions. Our research team will use advanced laboratory tools to explore the body's systems for controlling levels of Itch and how this control relates to cell growth. In particular, we will work towards an understanding of whether the molecules Pirh2 and Itch are critical parts of these control systems and how they can be influenced. Our plan is to study the two molecules in human cells, and to learn their relationship to each other and to other molecules that are involved with cell growth and normal development. Thus, the outcome of this proposal has significant implications for cell biology. We are hopeful that our research will contribute to our understanding of the molecular mechanism of interaction between RING E3 ligase Pirh2 and HECT E3 ligase Itch.

蛋白质是人体中最重要的分子之一。蛋白质稳定性和更新的调节是细胞中的关键任务。大多数蛋白质被泛素（UB） - 近端途径（UPP）降解。 UPP会影响UPP中多种细胞过程和底物以及缺陷会导致人类疾病的发病机理。 UPP在2004年获得诺贝尔化学奖的认可。泛素介导的蛋白质降解是一个涉及三种酶的三步过程：E1（UB-激活酶），E2（UB-Conjugating酶）（Ub-Conjugating酶）和E3（UB蛋白蛋白Ligase）。最近证明，一种新的泛素化酶E4（UB链组装因子）对于通过泛素融合降解途径降解某些蛋白是必不可少的。这些酶一起催化了一个或多个泛素部分与蛋白质赖氨酸残基的共价附着。 E3酶在底物的识别和泛素化中起着核心作用，并属于三个亚组：（i）诸如E6-apand Itch之类的hect域连接酶； （ii）环域连接酶，包括PIRH2和MDM2； （iii）代表非经典环域（例如UFD2和ChIP）（HSP70相互作用蛋白的羧基末端）的U-box结构域连接酶。随后将泛素化蛋白作为26S蛋白酶体降解的靶向。这两个分子属于E3连接酶家族，该家族促进蛋白质降解。我们先前证明PIRH2可以负调节瘙痒活动和功能。我们的研究团队将使用先进的实验室工具来探索人体的系统，以控制瘙痒水平以及该控制与细胞生长的关系。特别是，我们将努力理解分子PIRH2和瘙痒是否是这些控制系统的关键部分以及它们如何受到影响。我们的计划是研究人类细胞中的两个分子，并学习它们之间的关系以及与细胞生长和正常发育有关的其他分子。因此，该提案的结果对细胞生物学具有重要意义。我们希望我们的研究将有助于我们理解环E3连接酶PIRH2和HECT E3连接酶瘙痒之间相互作用的分子机制。