Ding Jin-Li, Zhang Hao, Feng Ming-Guang, Ying Sheng-Hua
Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
J Fungi (Basel). 2023 Feb 15;9(2):262. doi: 10.3390/jof9020262.
In yeast, Atg22 functions as a vacuolar efflux transporter to release the nutrients from the vacuole to the cytosol after the degradation of autophagic bodies. There are more than one Atg22 domain-containing proteins in filamentous fungi, but their physiological roles are largely unknown. In this study, four Atg22-like proteins (BbAtg22A through D) were functionally characterized in the filamentous entomopathogenic fungus . These Atg22-like proteins exhibit different sub-cellular distributions. BbAtg22A localizes in lipid droplets. BbAtg22B and BbAtg22C are completely distributed in the vacuole, and BbAtg22D has an additional association with the cytomembrane. The ablation of Atg22-like proteins did not block autophagy. Four Atg22-like proteins systematically contribute to the fungal response to starvation and virulence in . With the exception of ∆, the other three proteins contribute to dimorphic transmission. Additionally, BbAtg22A and BbAtg22D are required for cytomembrane integrity. Meanwhile, four Atg22-like proteins contribute to conidiation. Therefore, Atg22-like proteins link distinct sub-cellular structures for the development and virulence in . Our findings provide a novel insight into the non-autophagic roles of autophagy-related genes in filamentous fungi.
在酵母中，Atg22作为液泡外排转运体，在自噬体降解后将营养物质从液泡释放到细胞质中。丝状真菌中存在不止一种含Atg22结构域的蛋白质，但其生理作用在很大程度上尚不清楚。在本研究中，对丝状昆虫病原真菌中的四种Atg22样蛋白（BbAtg22A至D）进行了功能表征。这些Atg22样蛋白表现出不同的亚细胞分布。BbAtg22A定位于脂滴中。BbAtg22B和BbAtg22C完全分布在液泡中，而BbAtg22D还与细胞膜相关联。Atg22样蛋白的缺失并未阻断自噬。四种Atg22样蛋白系统地促进了真菌对饥饿的反应以及在……中的毒力。除了∆之外，其他三种蛋白有助于二态性转变。此外，BbAtg22A和BbAtg22D是细胞膜完整性所必需的。同时，四种Atg22样蛋白有助于分生孢子形成。因此，Atg22样蛋白将不同的亚细胞结构联系起来，以促进……中的发育和毒力。我们的发现为丝状真菌中自噬相关基因的非自噬作用提供了新的见解。
