Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.
Fujian Key Laboratory of Propagated Sensation along Meridian, Fujian Academy of Chinese Medical Sciences, Fuzhou, China.
Virulence. 2022 Dec;13(1):1358-1378. doi: 10.1080/21505594.2022.2101218.
infects various crops with aflatoxins, and leads to aspergillosis opportunistically. Though H3K36 methylation plays an important role in fungal toxin metabolism and virulence, no data about the biological function of H3K36 methylation in virulence has been reported. Our study showed that the Set2 histone methyltransferase family, AshA and SetB, involves in morphogenesis and mycotoxin anabolism by regulating related transcriptional factors, and they are important for fungal virulence to crops and animals. Western-blotting and double deletion analysis revealed that AshA mainly regulates H3K36me2, whereas SetB is mainly responsible for H3K36me3 in the nucleus. By construction of domain deletion strain and point mutation strains by homologous recombination, the study revealed that SET domain is indispensable in mycotoxin anabolism and virulence of , and N455 and V457 in it are the key amino acid residues. ChIP analysis inferred that the methyltransferase family controls fungal reproduction and regulates the production of AFB1 by directly regulating the production of the transcriptional factor genes, including , , and amylase, through H3K36 trimethylation in their chromatin fragments, based on which this study proposed that, by H3K36 trimethylation, this methyltransferase family controls AFB1 anabolism through transcriptional level and substrate utilization level. This study illuminates the epigenetic mechanism of the Set2 family in regulating fungal virulence and mycotoxin production, and provides new targets for controlling the virulence of the fungus .The methylation of H3K36 plays an important role in the fungal secondary metabolism and virulence, but no data about the regulatory mechanism of H3K36 methylation in the virulence of have been reported. Our study revealed that, in the histone methyltransferase Set2 family, AshA mainly catalyzes H3K36me2, and involves in the methylation of H3K36me1, and SetB mainly catalyzes H3K36me3 and H3K36me1. Through domain deletion and point mutation analysis, this study also revealed that the SET domain was critical for the normal biological function of the Set2 family and that N455 and V457 in the domain were critical for AshA. By ChIP-seq and ChIP-qPCR analysis, H3K36 was found to be trimethylation modified in the promotors and ORF positions of , and the amylase gene (AFLA_084340), and further qRT-PCR results showed that these methylation modifications regulate the expression levels of these genes. According to the results of ChIP-seq analysis, we proposed that, by H3K36 trimethylation, this methyltransferase family controls the metabolism of mycotoxin through transcriptional level and substrate utilization level. All the results from this study showed that Set2 family is essential for fungal secondary metabolism and virulence, which lays a theoretical groundwork in the early prevention and treatment of pollution, and also provides an effective strategy to fight against other pathogenic fungi.
其产生的黄曲霉毒素会感染各种作物，并导致曲霉病机会性感染。虽然 H3K36 甲基化在真菌毒素代谢和毒力中起着重要作用，但目前尚无关于 H3K36 甲基化在毒力方面的生物学功能的报道。我们的研究表明，Set2 组蛋白甲基转移酶家族、AshA 和 SetB 通过调节相关转录因子参与形态发生和真菌毒素生物合成，它们对真菌对作物和动物的毒力至关重要。Western-blotting 和双缺失分析表明，AshA 主要调节 H3K36me2，而 SetB 主要负责细胞核中的 H3K36me3。通过同源重组构建结构域缺失菌株和点突变菌株，研究表明 SET 结构域在真菌毒素生物合成和毒力中是必不可少的，并且其中的 N455 和 V457 是关键的氨基酸残基。ChIP 分析推断，甲基转移酶家族通过直接调控转录因子基因的表达，来控制真菌的繁殖和 AFB1 的产生，包括、、和淀粉酶，通过其染色质片段中 H3K36 的三甲基化，基于此，本研究提出该甲基转移酶家族通过转录水平和底物利用水平来控制 AFB1 生物合成。本研究阐明了 Set2 家族在调控真菌毒力和真菌毒素产生中的表观遗传机制，为控制真菌的毒力提供了新的靶点。H3K36 的甲基化在真菌的次生代谢和毒力中起着重要作用，但目前尚无关于 H3K36 甲基化在毒力中的调控机制的报道。我们的研究表明，在组蛋白甲基转移酶 Set2 家族中，AshA 主要催化 H3K36me2，并参与 H3K36me1 的甲基化，而 SetB 主要催化 H3K36me3 和 H3K36me1。通过结构域缺失和点突变分析，本研究还揭示了 SET 结构域对 Set2 家族的正常生物学功能至关重要，并且结构域中的 N455 和 V457 对 AshA 至关重要。通过 ChIP-seq 和 ChIP-qPCR 分析，发现 H3K36 在、和淀粉酶基因（AFLA_084340）的启动子和 ORF 位置发生了三甲基化修饰，进一步的 qRT-PCR 结果表明，这些修饰调控了这些基因的表达水平。根据 ChIP-seq 分析的结果，我们提出该甲基转移酶家族通过 H3K36 三甲基化来控制真菌毒素的代谢通过转录水平和底物利用水平。本研究的所有结果均表明，Set2 家族对真菌的次生代谢和毒力至关重要，这为早期预防和治疗污染奠定了理论基础，也为对抗其他致病性真菌提供了有效的策略。
