Cai Qing, Wang Juanjuan, Xie Jiatao, Jiang Daohong, Keyhani Nemat O
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA.
J Fungi (Basel). 2022 Aug 10;8(8):834. doi: 10.3390/jof8080834.
Transcriptional activity is mediated by chromatin remodeling, which in turn is affected by post-translational modifications, including histone acetylation. Histone acetyltransferases (HATs) are capable of promoting euchromatin formation and then activating gene transcription. Here, we characterize the Elp3 GNAT family HAT, which is also a subunit of Elongator complex, in the environmentally and economically important fungal insect pathogen, BbElp3 showed high localization levels to mitochondria, with some nuclear and cytoplasmic localization also apparent. Targeted gene knockout of resulted in impaired asexual development and morphogenesis, reduced tolerances to multiple stress conditions, reduced the ability of the fungus to utilize various carbon/nitrogen sources, increased susceptibility to rapamycin, and attenuated virulence in bioassays using the greater wax moth, . The Δ mutant also showed disrupted cell cycle, abnormal hyphal septation patterns, and enlarged autophagosomes in vegetative hyphae. Transcriptome analyses revealed differential expression of 775 genes (DEGs), including 336 downregulated and 438 upregulated genes in the Δ strain as compared to the wild type. Downregulated genes were mainly enriched in pathways involved in DNA processing and transcription, cell cycle control, cellular transportation, cell defense, and virulence, including hydrophobins, cellular transporters (ABC and MFS multidrug transporters), and insect cuticular degrading enzymes, while upregulated genes were mainly enriched in carbohydrate metabolism and amino acid metabolism. These data indicate pleiotropic effects of BbElp3 in impacting specific cellular processes related to asexual development, cell cycle, autophagy, and virulence.
转录活性由染色质重塑介导，而染色质重塑又受翻译后修饰的影响，包括组蛋白乙酰化。组蛋白乙酰转移酶（HATs）能够促进常染色质形成，进而激活基因转录。在此，我们对Elp3 GNAT家族HAT进行了表征，它也是延伸因子复合物的一个亚基，存在于具有环境和经济重要性的真菌昆虫病原体中。BbElp3在线粒体中显示出较高的定位水平，同时也有一些核定位和细胞质定位。对其进行靶向基因敲除导致无性发育和形态发生受损，对多种胁迫条件的耐受性降低，真菌利用各种碳/氮源的能力下降，对雷帕霉素的敏感性增加，并且在使用大蜡螟进行的生物测定中毒力减弱。Δ突变体在营养菌丝中还表现出细胞周期紊乱、异常的菌丝隔膜模式和自噬体增大。转录组分析揭示了775个基因（差异表达基因，DEGs）的差异表达，与野生型相比，Δ菌株中有336个基因下调和438个基因上调。下调的基因主要富集于参与DNA加工和转录、细胞周期控制、细胞运输、细胞防御和毒力的途径，包括疏水蛋白、细胞转运蛋白（ABC和MFS多药转运蛋白）以及昆虫表皮降解酶，而上调的基因主要富集于碳水化合物代谢和氨基酸代谢。这些数据表明BbElp3在影响与无性发育、细胞周期、自噬和毒力相关的特定细胞过程中具有多效性作用。
