Lv Wuyun, Xu Zhe, Talbot Nicholas J, Wang Zhengyi
State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China.
The Sainsbury Laboratory, Norwich Research Park, Norwich, UK.
Cell Microbiol. 2020 Aug;22(8):e13208. doi: 10.1111/cmi.13208. Epub 2020 Apr 30.
The sorting nexin Atg20/Snx42 plays an important role in autophagy. The wheat head blight pathogen Fusarium graminearum contains an FgAtg20 protein orthologous to Saccharomyces cerevisiae Atg20/Snx42, but its function remains largely unknown. Here, we report a role for FgAtg20 in regulating morphogenesis and fungal pathogenicity. Cytological observation and Western blot analysis revealed that ΔFgAtg20 mutants are defective in vacuolar transport and proteolysis of GFP-FgAtg8, indicating that FgAtg20 is required for non-selective macroautophagy. Furthermore, we found that FgATG20 is necessary for the maturation of FgApe1, an indicator of the cytoplasm-to-vacuole targeting (Cvt) pathway. Immunoblot analysis displayed lower level of FgPex14, a peroxisomal integral membrane protein in ΔFgAtg20 mutants, suggesting that pexophagy is impaired. Furthermore, we demonstrate that FgAtg20 forms a complex with FgAtg1, FgAtg11, FgAtg17 and FgAtg24. When considered together, we conclude that FgAtg20 plays a critical role in vegetative growth, conidiation and pathogenicity of the head blight pathogen, and is involved in the Cvt pathway, non-selective macroautophagy and pexophagy.
分选连接蛋白Atg20/Snx42在自噬过程中发挥着重要作用。小麦赤霉病病原菌禾谷镰刀菌含有一种与酿酒酵母Atg20/Snx42直系同源的FgAtg20蛋白,但其功能在很大程度上仍不清楚。在此,我们报道了FgAtg20在调节形态发生和真菌致病性方面的作用。细胞学观察和蛋白质免疫印迹分析表明,ΔFgAtg20突变体在液泡运输和GFP-FgAtg8的蛋白水解方面存在缺陷,这表明FgAtg20是非选择性巨自噬所必需的。此外,我们发现FgATG20对于FgApe1的成熟是必需的,FgApe1是细胞质到液泡靶向(Cvt)途径的一个指标。免疫印迹分析显示,ΔFgAtg20突变体中过氧化物酶体整合膜蛋白FgPex14的水平较低,这表明过氧化物酶体自噬受损。此外,我们证明FgAtg20与FgAtg1、FgAtg11、FgAtg17和FgAtg24形成复合物。综合考虑,我们得出结论,FgAtg20在赤霉病病原菌的营养生长、分生孢子形成和致病性中起关键作用,并参与Cvt途径、非选择性巨自噬和过氧化物酶体自噬。