UGT PROTEIN NETWORK AND THE CONTROL OF CELL METABOLISM.

UGT 蛋白质网络和细胞代谢的控制。

• 批准号: 342176-2012
• 负责人: Guillemette, Chantal
• 金额: $ 2.91万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=572468
• 关键词: UGT; PROTEIN; NETWORK; CONTROL; CELL

Glucuronidation, catalyzed by UDP-glucuronosyltransferases (UGTs), is crucial in higher eukaryotes for protection against imbalances in endobiotics (e.g., hormones, neurotransmitters) and harmful xenobiotics (e.g., pollutants, drugs). In humans, nine functional UGTs enzymes are encoded by a single gene, UGT1A. As a major breakthrough in the field, we discovered a novel post-transcriptional regulatory mechanism of cellular glucuronidation involving nine other shorter UGT1A proteins (named i2s) produced by alternative splicing. These i2s are enzymatically inactive but act as negative modulators of cellular metabolism by inhibiting the i1 enzymes in the endoplasmic reticulum (ER) through protein-protein interaction. In addition, i2s localize outside the ER, suggesting potential additional roles and interactions with new partner proteins. We hypothesized that UGT1As comprise a highly organized protein network that is shaped by proteins likely involved in modulating UGT1A-mediated activities (as initially observed for i2s) and possibly through interaction with novel partners that would reveal additional cellular functions for this family of proteins. Aim 1: To study protein-protein interactions between i1 enzymes and i2 regulators in the ER and define the interaction domains involved. Aim 2: To identify novel interacting partners (ER-resident and non-resident) to provide new insights into UGT1A-associated proteins involved in modulating glucuronidation activity and explore putative new functions for UGTs. We will use complementary approaches including mass spectrometry and the models and tools established in the last grant period. The findings may provide novel approaches to regulate or modulate the glucuronidation pathway. Identifying and understanding the role of protein-protein interactions is fundamental to understanding glucuronidation at the systems level and developing novel therapeutics. Our group has discover UGT1A splice variants and reveal their regulatory function for the first time; we thus have the unique expertise and tools to achieve the goals set forth in this proposal. Highly qualified students will continue to be trained throughout this research program.

由UDP-葡萄糖醛酸基转移酶（UGT）催化的葡萄糖醛酸化在高等真核生物中对于防止内生菌（例如，激素，神经递质）和有害的异生物质（例如，污染物、毒品）。在人类中，九种功能性UGT酶由单一基因UGT 1A编码。作为该领域的一项重大突破，我们发现了一种新的细胞葡萄糖醛酸化的转录后调节机制，涉及通过选择性剪接产生的其他九种较短的UGT 1A蛋白（命名为i2 s）。这些i2是无酶活性的，但通过蛋白质-蛋白质相互作用抑制内质网（ER）中的i1酶，作为细胞代谢的负调节剂。此外，i2 s定位于ER外，表明潜在的额外作用和与新伴侣蛋白的相互作用。我们假设UGT 1A包含一个高度组织化的蛋白质网络，该网络由可能参与调节UGT 1A介导的活性（如最初对i2观察到的）的蛋白质形成，并可能通过与新伴侣的相互作用来揭示该蛋白质家族的其他细胞功能。目的1：研究内质网中i1酶和i2调节因子之间的蛋白质-蛋白质相互作用，并确定相互作用的结构域。目标二：鉴定新型相互作用伴侣（ER-居民和非居民），为参与调节葡萄糖醛酸化活性的UGT 1A相关蛋白提供新的见解，并探索UGT的推定新功能。我们将使用互补的方法，包括质谱法和在上一个资助期建立的模型和工具。这些发现可能为调控葡萄糖醛酸化途径提供新的方法。识别和理解蛋白质-蛋白质相互作用的作用是在系统水平上理解葡萄糖醛酸化和开发新疗法的基础。我们的团队首次发现了UGT 1A剪接变体并揭示了它们的调控功能;因此，我们拥有独特的专业知识和工具来实现本提案中提出的目标。高素质的学生将在整个研究计划中继续接受培训。