Ding Jin-Li, Wei Kang, Feng Ming-Guang, Ying Sheng-Hua
Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
J Fungi (Basel). 2023 May 6;9(5):543. doi: 10.3390/jof9050543.
Autophagy is a conserved mechanism for the turnover of intracellular components. Among the 'core' autophagy-related genes (), the cysteine protease Atg4 plays an important role in the activation of Atg8 by exposing the glycine residue at its extreme carboxyl terminus. In the insect fungal pathogen , a yeast ortholog of Atg4 was identified and functionally analyzed. Ablation of the gene blocks the autophagic process during fungal growth under aerial and submerged conditions. Gene loss did not affect fungal radial growth on various nutrients, but Δ exhibited an impaired ability to accumulate biomass. The mutant displayed increased sensitivity to stress caused by menadione and hydrogen peroxide. Δ generated abnormal conidiophores with reduced production of conidia. Additionally, fungal dimorphism was significantly attenuated in gene disruption mutants. Disruption of resulted in significantly weakened virulence in topical and intrahemocoel injection assays. Our study indicates that BbAtg4 contributes to the lifecycle of via its autophagic roles.
自噬是一种保守的细胞内成分周转机制。在“核心”自噬相关基因中，半胱氨酸蛋白酶Atg4通过暴露其极端羧基末端的甘氨酸残基，在Atg8的激活中发挥重要作用。在昆虫真菌病原体中，鉴定并功能分析了Atg4的酵母直系同源物。该基因的缺失阻断了真菌在气生和淹没条件下生长过程中的自噬过程。基因缺失不影响真菌在各种营养物质上的径向生长，但Δ显示出积累生物量的能力受损。该突变体对甲萘醌和过氧化氢引起的应激表现出增加的敏感性。Δ产生异常分生孢子梗，分生孢子产量降低。此外，在基因破坏突变体中，真菌二态性显著减弱。在局部和血腔注射试验中，基因破坏导致毒力显著减弱。我们的研究表明，BbAtg4通过其自噬作用对该菌的生命周期有贡献。
