Duan Yuhang, Li Pingping, Zhang Deyao, Wang Lili, Fang Yuan, Hu Hong, Mao Qiulu, Zhou Xiaolan, Zhao Panpan, Li Xuechun, Wei Jinfeng, Tang Jintian, Pan Li, Liu Hao, Chen Xiaolin, Chen Xiaoyang, Hsiang Tom, Huang Junbin, Zheng Lu
State Key Laboratory of Agricultural Microbiology/Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan, China.
Anhui Province Key Laboratory of Crop Integrated Pest Management/College of Plant Protection, Anhui Agricultural University, Hefei, China.
mBio. 2024 Dec 11;15(12):e0270424. doi: 10.1128/mbio.02704-24. Epub 2024 Oct 29.
S-palmitoylation is an important reversible protein post-translational modification in organisms. However, its role in fungi is uncertain. Here, we found the treatment of the rice false fungus with S-palmitoylation inhibitor 2 BP resulted in a significant decrease in fungal virulence. Comprehensive identification of S-palmitoylation sites and proteins in revealed a total of 4,089 S-palmitoylation sites identified among 2,192 proteins and that S-palmitoylated proteins were involved in diverse biological processes. Among the five palmitoyltransferases, UvPfa3 and UvPfa4 were found to regulate the pathogenicity of . We then performed quantitative proteomic analysis of ∆ and ∆ mutants. Interestingly, S-palmitoylated proteins were significantly enriched in the mitogen-activated protein kinase and autophagy pathways, and MAP kinase UvSlt2 was confirmed to be an S-palmitoylated protein which was palmitoylated by UvPfa4. Mutations of S-palmitoylation sites in resulted in significantly reduced fungal virulence and decreased kinase enzymatic activity and phosphorylation levels. Simulations of molecular dynamics demonstrated mutation of S-palmitoylation sites in causing decreased hydrophobic solvent-accessible surface area, thereby weakening the bonding force with its substrate UvRlm1. Taken together, S-palmitoylation promotes virulence through palmitoylation of MAP kinase UvSlt2 by palmitoyltransferase UvPfa4. This enhances the enzymatic phosphorylation activity of the kinase, thereby increasing hydrophobic solvent-accessible surface area and binding activity between the UvSlt2 enzyme and its substrate UvRlm1. Our studies provide a framework for dissecting the biological functions of S-palmitoylation and reveal an important role for S-palmitoylation in regulating the virulence of the pathogen.IMPORTANCES-palmitoylation is an important post-translational lipid modification of proteins. However, its role in fungi is uncertain. In this study, we found that S-palmitoylation promotes virulence of rice false smut fungus through palmitoylation of MAP kinase UvSlt2 by palmitoyltransferase UvPfa4. This enhances the enzymatic phosphorylation activity of the kinase, thereby increasing hydrophobic solvent-accessible surface area and binding activity between the UvSlt2 enzyme and its substrate UvRlm1. Our studies provide a framework for dissecting the biological functions of S-palmitoylation and reveal an important role for S-palmitoylation in regulating the virulence of the pathogen. This is the first functional study to reveal the role of S-palmitoylation in fungal virulence.
S-棕榈酰化是生物体中一种重要的可逆蛋白质翻译后修饰。然而，其在真菌中的作用尚不确定。在此，我们发现用S-棕榈酰化抑制剂2-BP处理稻曲病菌会导致真菌毒力显著下降。对稻曲病菌中S-棕榈酰化位点和蛋白质的全面鉴定显示，在2192种蛋白质中总共鉴定出4089个S-棕榈酰化位点，且S-棕榈酰化蛋白质参与了多种生物学过程。在五种棕榈酰转移酶中，发现UvPfa3和UvPfa4可调节稻曲病菌的致病性。然后，我们对ΔUvPfa3和ΔUvPfa4突变体进行了定量蛋白质组学分析。有趣的是，S-棕榈酰化蛋白质在丝裂原活化蛋白激酶和自噬途径中显著富集，并且丝裂原活化蛋白激酶UvSlt2被证实是一种由UvPfa4棕榈酰化的S-棕榈酰化蛋白质。稻曲病菌中S-棕榈酰化位点的突变导致真菌毒力显著降低，激酶酶活性和磷酸化水平下降。分子动力学模拟表明，稻曲病菌中S-棕榈酰化位点的突变导致疏水溶剂可及表面积减小，从而削弱了其与底物UvRlm1的结合力。综上所述，S-棕榈酰化通过棕榈酰转移酶UvPfa4对丝裂原活化蛋白激酶UvSlt2进行棕榈酰化来促进稻曲病菌的毒力。这增强了激酶的酶促磷酸化活性，从而增加了疏水溶剂可及表面积以及UvSlt2酶与其底物UvRlm1之间的结合活性。我们的研究为剖析S-棕榈酰化的生物学功能提供了一个框架，并揭示了S-棕榈酰化在调节病原体毒力中的重要作用。
重要性
S-棕榈酰化是一种重要的蛋白质翻译后脂质修饰。然而，其在真菌中的作用尚不确定。在本研究中，我们发现S-棕榈酰化通过棕榈酰转移酶UvPfa4对丝裂原活化蛋白激酶UvSlt2进行棕榈酰化来促进稻曲病菌的毒力。这增强了激酶的酶促磷酸化活性，从而增加了疏水溶剂可及表面积以及UvSlt2酶与其底物UvRlm1之间的结合活性。我们的研究为剖析S-棕榈酰化的生物学功能提供了一个框架，并揭示了S-棕榈酰化在调节病原体毒力中的重要作用。这是首次揭示S-棕榈酰化在真菌毒力中作用的功能研究。
