PDF(Pubmed)
Abstract：
As a signaling molecule, nitric oxide (NO) regulates the development and stress response in different organisms. The major biological activity of NO is protein S-nitrosylation, whose function in fungi remains largely unclear. Here, it is found in the rice blast fungus Magnaporthe oryzae, de-nitrosylation process is essential for functional appressorium formation during infection. Nitrosative stress caused by excessive accumulation of NO is harmful for fungal infection. While the S-nitrosoglutathione reductase GSNOR-mediated de-nitrosylation removes excess NO toxicity during appressorium formation to promote infection. Through an indoTMT switch labeling proteomics technique, 741 S-nitrosylation sites in 483 proteins are identified. Key appressorial proteins, such as Mgb1, MagB, Sps1, Cdc42, and septins, are activated by GSNOR through de-nitrosylation. Removing S-nitrosylation sites of above proteins is essential for proper protein structure and appressorial function. Therefore, GSNOR-mediated de-nitrosylation is an essential regulator for appressorium formation. It is also shown that breaking NO homeostasis by NO donors, NO scavengers, as well as chemical inhibitor of GSNOR, shall be effective methods for fungal disease control.
摘要：
作为信号分子，一氧化氮（NO）调节不同生物体的发育和应激反应。NO的主要生物活性是蛋白质S-亚硝基化,其在真菌中的功能仍不清楚。这里,它在稻瘟病真菌稻瘟病菌中发现，脱亚硝基化过程对于感染过程中的功能性附着层形成至关重要。NO过度积累引起的硝化应激对真菌感染有害。而S-亚硝基谷胱甘肽还原酶GSNOR介导的脱亚硝基化可在附睾形成过程中消除过量的NO毒性以促进感染。通过indoTMT开关标记蛋白质组学技术，鉴定了483种蛋白质中的741S-亚硝基化位点。关键吸食蛋白，如MgB1、MagB、Sps1、Cdc42和隔膜，被GSNOR通过脱亚硝基活化。去除上述蛋白质的S-亚硝基化位点对于适当的蛋白质结构和表观功能至关重要。因此,GSNOR介导的脱亚硝基化是附着层形成的重要调节因子。还表明，NO供体打破NO稳态，没有清除剂,以及GSNOR的化学抑制剂，是控制真菌病的有效方法。
