Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, United Kingdom.
Plant Sci. 2011 Nov;181(5):540-4. doi: 10.1016/j.plantsci.2011.04.004. Epub 2011 Apr 21.
A key feature of the plant defence response is the transient engagement of a nitrosative burst, resulting in the synthesis of reactive nitrogen intermediates (RNIs). Specific, highly reactive cysteine (Cys) residues of low pK(a) are a major site of action for these intermediates. The addition of an NO moiety to a Cys thiol to form an S-nitrosothiol (SNO), is termed S-nitrosylation. This redox-based post-translational modification is emerging as a key regulator of protein function in plant immunity. Here we highlight recent advances in our understanding of de-nitrosylation, the mechanism that depletes protein SNOs, with a focus on S-nitrosoglutathione reductase (GSNOR). This enzyme controls total cellular S-nitrosylation indirectly during the defence response by turning over S-nitrosoglutathione (GSNO), a major cache of NO bioactivity.
植物防御反应的一个主要特征是短暂地引发硝化爆发，导致活性氮中间产物（RNIs）的合成。低 pK(a) 的特定、高反应性半胱氨酸 (Cys) 残基是这些中间产物的主要作用位点。将 NO 部分添加到 Cys 巯基上形成 S-亚硝酰硫醇 (SNO)，称为 S-亚硝化。这种基于氧化还原的翻译后修饰正在成为植物免疫中蛋白质功能的关键调节剂。在这里，我们强调了我们对去硝化作用的理解的最新进展，即消耗蛋白质 SNO 的机制，重点是 S-亚硝基谷胱甘肽还原酶 (GSNOR)。该酶通过转化 S-亚硝酰谷胱甘肽（GSNO）间接控制细胞内总 S-亚硝化作用，GSNO 是 NO 生物活性的主要储存库。
