基于蛋白基因组学的黄曲霉菌基因组重注释及蛋白质翻译后修饰的全局鉴定

Aspergillus flavus (A. flavus) is a saprophytic filamentous fungus distributed all over the world that produces highly toxic and carcinogenic aflatoxins. The genome of A. flavus has been released and the aflatoxin biosynthesis pathway has been established, however, recent studies have implied that A. flavus genome codes novel genes and the regulation between posttranslational modifications (PTMs) and aflatoxin biogenesis in A. flavus has not yet been established. In the project, we try to integrate genomic, transcriptomic and proteomic data to build a comprehensive genome annotation of A. flavus using proteogenomics approaches. The discovery of novel genes and gene annotation refinement provides a stable foundation for identification of secondary metabolic gene clusters in A. flavus. Using unrestrictive database search algorithms, all possible PTMs in A. flavus are identified at once. The modified proteins were mapped to protein-protein interaciton network for constrcting a comprehensive PTM network in A. flavus. This proteomic analysis of A. flavus not only provides global profiling of PTMs in A. flavus but also reveals that unappreciated roles for PTMs in the regulation of aflatoxins production. Our finding will shed light on the study of control of aflatoxin contamination.

黄曲霉菌是一种常见的腐生霉菌，能产生致命的次级代谢产物黄曲霉毒素。尽管黄曲霉菌的基因组测序已完成，黄曲霉毒素合成途径已被发现，但是研究发现黄曲霉基因组的部分基因未被注释，蛋白质翻译后修饰对黄曲霉毒素合成的调控还未被系统地研究过。本项目以黄曲霉菌为材料，利用蛋白基因组技术，整合基因组、转录组和蛋白组等多组学数据，挖掘新基因并校正已注释基因，构建更完善的黄曲霉基因组注释库，为黄曲霉的次级代谢基因簇的研究奠定扎实的基础；利用非限制性翻译后修饰搜索算法系统地鉴定黄曲霉在不同胁迫条件下的蛋白质翻译后修饰事件，通过整合蛋白质互作网络信息来构建黄曲霉翻译后修饰网络，以期初步探明蛋白质翻译后修饰对黄曲霉毒素合成的调控机制，为研究黄曲霉毒素危害的防控技术提供新的方向。

黄曲霉菌是一种常见的腐生霉菌，能产生致命的次级代谢产物黄曲霉毒素。尽管黄曲霉菌的基因组测序已完成，黄曲霉毒素合成途径已被发现，但是研究发现黄曲霉基因组的部分基因未被注释，蛋白质翻译后修饰对黄曲霉毒素合成的调控还未被系统地研究过。本项目以黄曲霉菌为材料，利用蛋白基因组技术，整合基因组、转录组和蛋白组等多组学数据，挖掘新基因并校正已注释基因，构建更完善的黄曲霉基因组注释库，利用非限制性翻译后修饰搜索算法系统地鉴定黄曲霉在不同胁迫条件下的蛋白质翻译后修饰事件。我们敲除了2个新鉴定基因（Fab1和CTA1），发现两个基因的突变都能影响黄曲霉生长发育、胁迫应答、黄曲霉侵染农作物的种子和毒素的生物合成等过程。结果表明Fab1是影响液泡的稳态，而CTA1是通过维持ROS的稳态来分别影响黄曲霉毒素的合成。我们的研究表明蛋白基因组技术能提高黄曲霉基因组注释水平，新注释的基因可能为调控黄曲霉毒素合成研究提供新的靶标基因。