Chen Chang, He Jia, Gao Wenyan, Wei Yanmin, Liu Gang
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100,101, China.
The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100864, China.
Curr Microbiol. 2019 May;76(5):545-551. doi: 10.1007/s00284-019-01650-7. Epub 2019 Mar 21.
Autophagy is a highly conserved mechanism to overcome various stresses and recycle cytoplasmic components and organelles. Ubiquitin-like (UBL) protein Atg12 is a key protein involved in autophagosome formation through stimulation of Atg8 conjugation to phosphatidylethanolamine. Here, we describe the identification of the autophagy-related gene Acatg12, encoding an Atg12 homologous protein in the cephalosporin C producing fungus Acremonium chrysogenum. Disruption of Acatg12 impaired the delivery and degradation of eGFP-Atg8, indicating that the autophagic process was blocked. Meanwhile, conidiation was dramatically reduced in the Acatg12 disruption mutant (∆Acatg12). In contrast, cephalosporin C production was increased twofold in ∆Acatg12, but fungal growth was reduced after 6 days fermentation. Consistent with these results, the transcriptional level of the cephalosporin biosynthetic genes was increased in ∆Acatg12. The results extend our understanding of autophagy in filamentous fungi.
自噬是一种高度保守的机制，用于克服各种应激并循环利用细胞质成分和细胞器。类泛素（UBL）蛋白Atg12是一种关键蛋白，通过刺激Atg8与磷脂酰乙醇胺结合参与自噬体形成。在此，我们描述了在头孢菌素C产生菌产黄青霉中鉴定出的自噬相关基因Acatg12，其编码一种Atg12同源蛋白。Acatg12的破坏损害了eGFP-Atg8的转运和降解，表明自噬过程被阻断。同时，Acatg12破坏突变体（∆Acatg12）中的分生孢子形成显著减少。相反，∆Acatg12中的头孢菌素C产量增加了两倍，但发酵6天后真菌生长受到抑制。与这些结果一致，头孢菌素生物合成基因的转录水平在∆Acatg12中有所增加。这些结果扩展了我们对丝状真菌自噬的理解。
