Novel Posttranslational Modifications in Adipose Biology

项目摘要 代谢健康取决于维持正常的质量和功能的脂肪组织（AT）。 过量体脂的积累或AT的病理性丧失与胰岛素抵抗相关， 心脏代谢疾病白色AT（WAT）和棕色AT（BAT）共同作用， 积累和能量消耗。监管WAT和BAT维护的上游参与者仍然较少 表征了泛素（Ub）和Ub样蛋白修饰不同的蛋白质底物，并扩展功能， 蛋白质组的多样性。然而，NEDD 8的功能作用，一种新的Ub样蛋白，具有最高的 在脂肪组织中，与Ub的同源性仍然知之甚少。Neddylation将NEDD 8共价连接至 通过NEDD 8特异性E1-E2-E3酶靶向蛋白。NAE 1（一种调节亚基）的诱导脂肪缺失 的NEDD 8 E1酶）导致脂肪组织的损失可能通过线粒体功能障碍 和炎症。药理学抑制neddylation促进线粒体ROS的产生， 成熟脂肪细胞中线粒体功能受损。有趣的是，AT特异性CUL 3的丢失（一种真正的 neddylation靶标）在很大程度上表型模仿了neddylation缺陷诱导的AT丧失，而neddylation占主导地位 靶向CUL 3以调节线粒体功能和脂肪细胞更新。在BAT中，neddylation缺陷导致 BAT萎缩和非经典NF-κB信号传导的激活。这些令人信服的初步数据构成了 我们的中心假设，neddylation是需要成熟的白色和棕色脂肪组织， 通过调节CUL 3介导的线粒体功能和/或非经典NF-κB来维持 促炎信号传导。目的1建立neddylation的意义并鉴定其蛋白质组 调节线粒体功能障碍，脂肪组织重塑，从而调节能量平衡和适应性 产热作用目的2将剖析neddylation靶向一个新的线粒体的分子基础 靶向CUL 3 E3 Ub连接酶介导脂肪细胞线粒体活性和周转，从而实现能量平衡。目的 3将阐明一个新发现的neddylation靶点，介导非经典NF-κB信号转导，以加速细胞凋亡。 棕色脂肪细胞炎症和周转。我们建议的研究将提供最深入的分析， neddylation作为迄今为止成熟白色和棕色脂肪必需的新型翻译后修饰 组织维护我们希望这项提案的新发现将为我们的研究提供新的见解。 了解脂肪组织的病理生理学及其对肥胖/脂肪代谢障碍的影响， 相关的代谢紊乱。

Project Summary Metabolic health depends on the maintenance of normal mass and function of adipose tissue (AT). Accumulation of excess body fat or pathological loss of AT is associated with insulin resistance and cardiometabolic diseases. White AT (WAT) and brown AT (BAT) act together to maintain a balance between fat accumulation and energy expenditure. Upstream players that regulate WAT and BAT maintenance remain less characterized. Ubiquitin (Ub) and Ub-like proteins modify diverse protein substrates and expand the functional diversity of the proteome. However, the functional role of NEDD8, a novel Ub-like protein that has the highest homology with Ub, remains poorly understood in the adipose tissue. Neddylation covalently attaches NEDD8 to target proteins via NEDD8-specific E1-E2-E3 enzymes. Induced adipose deletion of NAE1 (a regulatory subunit of the NEDD8 E1 enzyme) in mice resulted in loss of adipose tissue potentially through mitochondrial dysfunction and inflammation. Pharmacological inhibition of neddylation promoted mitochondrial ROS production and impaired mitochondrial function in mature adipocytes. Interestingly, AT-specific loss of CUL3 (a bona fide neddylation target) largely phenocopied neddylation deficiency-induced AT loss, and neddylation dominantly targets CUL3 to modulate mitochondrial function and adipocyte turnover. In BAT, neddylation deficiency causes BAT atrophy and activation of non-canonical NF-κB signaling. These compelling preliminary data form the basis of our central hypothesis that neddylation is required for mature white and brown adipose tissue maintenance through regulation of CUL3-mediated mitochondrial function and/or non-canonical NF-κB pro-inflammatory signaling. Aim 1 will establish the significance and identify the proteome of neddylation in regulating mitochondrial dysfunction, adipose tissue remodeling and thus energy balance and adaptive thermogenesis. Aim 2 will dissect the molecular basis by which neddylation targets a novel mitochondrial targeted CUL3 E3 Ub ligase to mediate adipocyte mitochondrial activity and turnover thus energy balance. Aim 3 will elucidate a newly identified neddylation target in mediating non-canonical NF-κB signaling to accelerate brown adipocyte inflammation and turnover. Our proposed study will provide the most in-depth analysis of neddylation as a hitherto novel post-translational modification essential for both mature white and brown adipose tissue maintenance. We expect that new findings from this proposal will provide novel insights into our understanding of the pathophysiology of adipose tissue and its implications on obesity/ lipodystrophy and its associated metabolic disorders.