Rouleau Michèle, Audet-Delage Yannick, Desjardins Sylvie, Rouleau Mélanie, Girard-Bock Camille, Guillemette Chantal
Pharmacogenomics Laboratory, Canada Research Chair in Pharmacogenomics, Faculty of Pharmacy, Centre Hospitalier Universitaire de Québec Research Center, Laval University Québec, QC, Canada.
Front Pharmacol. 2017 Feb 3;8:23. doi: 10.3389/fphar.2017.00023. eCollection 2017.
The conjugative metabolism mediated by UDP-glucuronosyltransferase enzymes (UGTs) significantly influences the bioavailability and biological responses of endogenous molecule substrates and xenobiotics including drugs. UGTs participate in the regulation of cellular homeostasis by limiting stress induced by toxic molecules, and by controlling hormonal signaling networks. Glucuronidation is highly regulated at genomic, transcriptional, post-transcriptional and post-translational levels. However, the UGT protein interaction network, which is likely to influence glucuronidation, has received little attention. We investigated the endogenous protein interactome of human UGT1A enzymes in main drug metabolizing non-malignant tissues where UGT expression is most prevalent, using an unbiased proteomics approach. Mass spectrometry analysis of affinity-purified UGT1A enzymes and associated protein complexes in liver, kidney and intestine tissues revealed an intricate interactome linking UGT1A enzymes to multiple metabolic pathways. Several proteins of pharmacological importance such as transferases (including UGT2 enzymes), transporters and dehydrogenases were identified, upholding a potential coordinated cellular response to small lipophilic molecules and drugs. Furthermore, a significant cluster of functionally related enzymes involved in fatty acid β-oxidation, as well as in the glycolysis and glycogenolysis pathways were enriched in UGT1A enzymes complexes. Several partnerships were confirmed by co-immunoprecipitations and co-localization by confocal microscopy. An enhanced accumulation of lipid droplets in a kidney cell model overexpressing the UGT1A9 enzyme supported the presence of a functional interplay. Our work provides unprecedented evidence for a functional interaction between glucuronidation and bioenergetic metabolism.
由尿苷二磷酸葡萄糖醛酸基转移酶（UGTs）介导的共轭代谢显著影响内源性分子底物和包括药物在内的外源性物质的生物利用度和生物学反应。UGTs通过限制有毒分子诱导的应激以及控制激素信号网络来参与细胞稳态的调节。葡萄糖醛酸化在基因组、转录、转录后和翻译后水平上受到高度调控。然而，可能影响葡萄糖醛酸化的UGT蛋白质相互作用网络却很少受到关注。我们使用一种无偏见的蛋白质组学方法，研究了在UGT表达最为普遍的主要药物代谢非恶性组织中人类UGT1A酶的内源性蛋白质相互作用组。对肝脏、肾脏和肠道组织中亲和纯化的UGT1A酶及相关蛋白质复合物进行质谱分析，揭示了一个将UGT1A酶与多种代谢途径联系起来的复杂相互作用组。鉴定出了几种具有药理学重要性的蛋白质，如转移酶（包括UGT2酶）、转运蛋白和脱氢酶，这支持了细胞对小分子亲脂性分子和药物可能存在的协同反应。此外，参与脂肪酸β氧化以及糖酵解和糖原分解途径的一组功能相关酶在UGT1A酶复合物中显著富集。通过共免疫沉淀和共聚焦显微镜共定位证实了几种相互作用关系。在过表达UGT1A9酶的肾细胞模型中脂滴积累增加，支持了功能相互作用的存在。我们的工作为葡萄糖醛酸化与生物能量代谢之间的功能相互作用提供了前所未有的证据。
