基于蛋白质组学的蛋白N端新型酰化修饰系统研究

Protein post-translational modifications (PTMs) are important regulatory mechanisms that participate in several biological activities. Among them, lysine acylation is widely studied and is essential in regulating various biological functions, such as epigenetics and energy metabolism. Several studies have proved that lysine acylation is closely related to the occurrence and development of many diseases. Compared with lysine acylation, protein N-terminal acylation has unique biological features. However, studies on the Protein N-terminal acylation are relatively lagging, especially for novel acylation modification of protein N-terminal. Substrate characteristics, dynamic changes, and functional mechanisms of protein N-terminal acylation still need further exploration. In this project, we take the advantage of proteomics in studying PTMs by combining the protein N-terminal peptide enrichment and PTMiner software-based PTM spectrum analysis. We explore the systematic distribution of novel acylation modifications of protein N-terminal in different species, which elucidates the evolution features of this type of modification in different species. Furthermore, dynamic changes of N-terminal acylation modifications under different conditions, the new substrates of regulatory enzymes, and its intrinsic regulatory networks are conducted. This project uncovers the biological effects of protein N-terminal acylation, which enriches the scientific connotations of PTM and lays the foundation for further understanding of the physiological functions and pathological mechanisms of this new modification.

蛋白翻译后修饰是生命活动中重要的调控机制。赖氨酸酰化修饰作为研究最为广泛的蛋白翻译后修饰类型之一，对于表观遗传及能量代谢等多种生物学功能调控至关重要，并与诸多疾病的发生、发展密切相关。相比于蛋白赖氨酸酰化修饰而言，蛋白N端酰化修饰具有独特的生物学特性，但目前针对蛋白N端酰化修饰，尤其是非乙酰化的新型酰化修饰的研究相对滞后，其底物特征、动态变化、功能机制仍需进一步探索。本项目将利用蛋白质组学在研究新型蛋白翻译后修饰中的独特优势，交叉融合包括蛋白N端肽段富集，PTMiner软件修饰谱图解析在内的多种技术手段，全面解析不同物种中蛋白N端新型酰化修饰的系统性分布，阐明该类修饰在物种进化中的重要演变过程，揭示不同条件下N端酰化修饰的动态变化，鉴定修饰调控酶的新底物及内在调控网络，阐明蛋白N端酰化修饰的生物学效应，丰富蛋白翻译后修饰的科学内涵，也为深入认知该类修饰的生理功能和病理机制奠定基础。

蛋白翻译后修饰涉及包括细胞的生长、分化、代谢、信号转导、命运决定等所有细胞生命过程的调控，并与诸多生理，病理的发生、发展过程密切相关，极大地丰富了遗传信息的多样性。相比于赖氨酸修饰，蛋白N端修饰具有独特的生物学活性，参与调控多种生物学过程，但由于方法学的局限性，对于其底物和功能的认知知之甚少，极大地限制了对于N端动态网络和生物学调控机制的理解。因此，在本项目中，我们针对这一科学问题，开展了系统性的研究工作，主要分为以下几部分内容：1）构建了从低等原核生物到高等哺乳动物蛋白N端修饰谱的分子全景和不同营养条件下的动态表征；2）揭示EZH2野生和突变细胞株蛋白N端修饰的系统性变化；3）解析组蛋白去乙酰化酶抑制剂干预后蛋白N端乙酰化修饰和赖氨酸乙酰化修饰的潜在关联性；4）全景解析肺腺癌的癌组织相对于癌旁组织蛋白N端乙酰转移酶和整体赖氨酸乙酰化修饰的动态差异性。整体而言，本项目的研究成果促进了对于蛋白N端翻译后修饰的系统性认知，为进一步理解蛋白N端修饰的生理、病理功能提供了重要资源和工作基础。