Molecular Mechanisms, Pathways and Inhibition of Acetyl-Transfer Reactions

蛋白质和RNA的乙酰化，以及产生细胞代谢物的乙酰基转移反应，是 进化上保守的、对生命必不可少的修改。翻译后或共翻译后的乙酰化 蛋白质为生物体对外部和内部刺激做出反应提供了一种基本的机制；例如 包括组蛋白对组蛋白赖氨酸侧链的e-氨基的乙酰化 乙酰转移酶(HATS)或由N-末端乙酰基转移酶(NAT)组成的N-末端a-氨基， 以及由Nat10在胞苷碱基N4位的乙酰化反应。乙酰基转移反应 产生细胞代谢物，可以调节必要的细胞构建块的生物合成； 例子包括：由三磷酸腺苷-柠檬酸裂解酶(ACLY)产生的乙酰辅酶A和乙酰辅酶A合成酶。 链家族成员2(ACSS2)；由脂肪酸合成酶(FASN)产生的脂肪酸；以及胆固醇和 通过许多酶的顺序反应形成的类异戊二烯。调节乙酰的酶- 转移反应通常在多结构域蛋白或多亚单位蛋白的背景下起作用 在同源底物识别和靶向调控中起重要作用的络合物 和/或催化保真度。不同的蛋白质结构域和蛋白质辅助因子是如何协同作用的 各自的乙酰基转移反应仍然知之甚少。与它们的生物学重要性相关， 乙酰基转移酶或其调节蛋白的异常活性与 几种疾病，包括癌症、罕见的遗传疾病、心血管疾病和代谢疾病 神经退行性综合征，从而使这些酶吸引治疗的药物靶点。已被占用 总而言之，乙酰转移反应在绝大多数人体内起着重要的调节作用。 蛋白质组、RNA组和代谢组以及异常的乙酰转移反应功能与 人类疾病。尽管乙酰转移反应很重要，但关于 人们对它们不同的调控模式知之甚少，针对它们的药理药物是 不可用。在这个提案中，我们将解决以下广泛的问题，这些问题是乙酰转移的基础 反应：(A)蛋白质和RNA乙酰转移酶如何调节底物专一性？(B)如何 辅助蛋白和核糖体结合对NAT功能有贡献吗？(C)乙酰辅酶A如何 新陈代谢与染色质调节和脂肪酸合成有关？(D)我们能否利用机械性和 为乙酰基转移反应开发有效和选择性抑制剂的结构信息？一起， 这些研究将揭示常见的乙酰转移酶折叠是如何被其他蛋白质或结构域调节的 介导不同底物的乙酰化，N-末端蛋白乙酰化是如何受调控的 和相关因素，剖析了必需的乙酰转移酶的分子机制，并提供了 探索更好地了解乙酰转移酶的生物学，对治疗具有明确的意义。

The acetylation of proteins and RNA, and acetyl-transfer reactions that produce cellular metabolites, are evolutionarily conserved modifications that are essential for life. The post- or co-translational acetylation of proteins provides an essential mechanism for organisms to react to external and internal stimuli; examples include acetylation of the e-amino group of lysine side chains of histone proteins by histone acetyltransferases (HATs) or the N-terminal a-amino group by N-terminal acetyltransferases (NATs), respectively; and the acetylation at the N4 position of cytidine bases by Nat10. Acetyl-transfer reactions produce cellular metabolites that can mediate the biosynthesis of essential cellular building blocks; examples include: acetyl-CoA produced by ATP-citrate lyase (ACLY) and acetyl-CoA synthetase short- chain family member 2 (ACSS2); fatty acids produced by Fatty Acid Synthase (FASN); and cholesterol and isoprenoids formed through the sequential reactions of many enzymes. The enzymes that mediate acetyl- transfer reactions often function in the context of multiple domain proteins or multisubunit protein complexes, which play essential roles in the regulation of cognate substrate recognition and targeting and/or catalytic fidelity. How the various protein domains and protein cofactors cooperate for their respective acetyl-transfer reactions remains poorly understood. Correlating with their biological importance, the aberrant activities of acetyl-transfer enzymes or their regulatory proteins have been associated with several maladies including cancers, rare genetic disorders, cardiovascular diseases and metabolic and neurodegenerative syndromes, thus making these enzymes attractive drug targets for therapy. Taken together, acetyl-transfer reactions play an important regulatory function in the vast majority of the human proteome, RNAome and metabolome, and aberrant acetyl-transfer reaction function is correlated with human disease. Despite the importance of acetyl-transfer reactions, mechanistic information regarding their distinct modes of regulation are poorly understood and pharmacological agents that target them are not available. In this proposal, we will address the following broad questions underlying acetyl-transfer reactions: (A) How do protein and RNA acetyltransferases mediate substrate specificity? (B) How do auxiliary proteins and ribosome association contribute to NAT function? (C) How does acetyl-CoA metabolism link to chromatin regulation and fatty acid synthesis? (D) Can we leverage mechanistic and structural information to develop potent and selective inhibitors for acetyl-transfer reactions? Together, these studies will reveal how a common acetyltransferase fold is modulated by other proteins or domains to mediate the acetylation of distinct substrates, how N-terminal protein acetylation is modulated by regulatory and associated factors, dissect the molecular mechanism of essential acetyl-transfer enzymes, and provide probes to better understand the biology of acetyl-transfer enzymes with clear implications for therapy.