Metabolic regulation and inhibition of ATP-citrate lyase

这项建议的总体目标是剖析atp-柠檬酸代谢调节的分子机制。 裂解酶(ACLY)和用于癌症治疗的ACLY抑制剂的特征。ACLY是主要的来源 核浆乙酰-辅酶A，脂肪酸，胆固醇， 类异戊二烯和蛋白质乙酰化。在代谢紊乱、心血管疾病中发现ACLY活性升高 疾病和许多癌症，促使几种ACLY抑制剂的开发。而许多ACLY 已经开发出的抑制剂只有苯培多酸，它在体内形成了一种活性的苯培多基-CoA加合物 肝细胞，已被FDA批准用于治疗。患肝细胞癌的风险增加 代谢紊乱的患者，其中许多人可能是苯巴多酸治疗的候选对象； 然而，ACLY活性的代谢调节及其在肝细胞癌中的功能作用仍然很差。 明白了。K540、K546和K554的ACLY乙酰化水平和S455和K554的磷酸化水平升高 S481和编码S481区域的外显子14的保留也与癌症相关，因此也 提示ACLY翻译后和转录后修饰在癌症代谢中的作用。ACLY 是一种~500 kD的多结构域同四聚体，使用柠檬酸盐、辅酶A和三磷酸腺苷共底物来生产 草酰乙酸酯(OAA)和乙酰辅酶A。直到最近，缺乏关于完整的人类ACLY的结构信息 阻碍了对其催化的分子机制和基于结构的发展的理解 抑制剂。Wellen实验室最近报告了与以下疾病相关的各种表型 Marmorstein实验室报道了不同类型ACLY的冷冻-EM结构。 反应状态，以及相关的生化和生物物理研究，以阐明 ACLY法生产乙酰辅酶A。后一项发现导致了几个悬而未决的问题 ACLY的代谢调节，为基于结构的发育奠定了更强大的基础和 用于治疗应用的选择性ACLY抑制剂。这些最近的研究现在定位了韦伦和 Marmorstein实验室将共同努力，解决代谢调节和 通过以下特定目的抑制ACLY：(1)评价代谢结合物在ACLY中的作用 活性，(2)决定翻译后修饰和外显子14保留的分子机制 影响ACLY的调控；(3)评价ACLY抑制剂的分子作用方式。加在一起，这些 研究将揭示ACLY活性和调节如何由结合介导的分子机制 代谢物，以及转录后和翻译后修饰，将导致理性 开发治疗癌症的ACLY药物。

The overall goal of this proposal is to dissect the molecular mechanisms of metabolic regulation of ATP-citrate lyase (ACLY) and to characterize ACLY inhibitors for cancer therapy. ACLY is the predominant source of nucleocytosolic acetyl-CoA, an essential building block for the production of fatty acids, cholesterol, isoprenoids and protein acetylation. Elevated ACLY activity is found in metabolic disorders, cardiovascular diseases and many cancers, prompting the development of several ACLY inhibitors. While many ACLY inhibitors have been developed, only bempedoic acid, which forms an active bempedoyl-CoA adduct in hepatocytes, has been approved by the FDA for therapeutic use. Risk of hepatocellular carcinoma is elevated in individuals with metabolic disorders, many of whom may be candidates for treatment with bempedoic acid; yet metabolic regulation of ACLY activity and its functional role in hepatocellular carcinoma remain poorly understood. Elevated levels of ACLY acetylation at K540, K546 and K554 and phosphorylation at S455 and S481, and retention of exon 14 encoding a region with S481, have also been correlated with cancer, thus also suggesting roles for ACLY posttranslational and posttranscriptional modification in cancer metabolism. ACLY is an ~500 kD multidomain homotetrameric enzyme that uses citrate, CoA and ATP cosubstrates to produce oxaloacetate (OAA) and acetyl-CoA. Until recently, the lack of structural information on intact human ACLY has hampered understanding of its molecular mechanism of catalysis and the structure-based development of inhibitors. The Wellen lab recently reported on various disease-associated phenotypes associated with dysregulated ACLY function; and the Marmorstein lab reported on the cryo-EM structures of ACLY in different reaction states, along with associated biochemical and biophysical studies, to elucidate the molecular basis for acetyl-CoA production by ACLY. The latter findings lead to several unresolved questions underlying the metabolic regulation of ACLY and set the stage for the structure-based development of more potent and selective ACLY inhibitors for therapeutic applications. These recent studies now position the Wellen and Marmorstein labs to work together to resolve important gaps in knowledge in metabolic regulation and inhibition of ACLY, through the following specific aims: (1) Evaluate the role of metabolic binders in ACLY activity, (2) Determine the molecular mechanism of how posttranslational modifications and exon 14 retention impact ACLY regulation, and (3) Evaluate the molecular mode of action of ACLY inhibitors. Together, these studies will reveal the molecular mechanisms for how ACLY activity and regulation is mediated by the binding of metabolites, and posttranscriptional and posttranslational modification and will lead to the rational development of ACLY drugs to treat cancer.