A Genetic Analysis of Nitrosative Stress
A Genetic Analysis of Nitrosative Stress
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DOI：
10.1021/bi801813n
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发表时间：
2009-02-03
期刊：
影响因子：
2.9
通讯作者：
Stamler, Jonathan S.
中科院分区：
文献类型：
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作者：
Foster, Matthew W.;Liu, Limin;Stamler, Jonathan S.
亚硝化应激由一氧化氮（NO）和S-亚硝基硫醇（例如，S-亚硝基谷胱甘肽，GSNO），并产生，至少在显着的部分，从关键蛋白质半胱氨酸巯基（S-亚硝基化）和金属辅因子的亚硝基化。然而，NO和GSNO介导亚硝化应激的机制还不清楚。使用酵母酿酒酵母菌株缺乏NO和/或GSNO消耗酶（黄素血红蛋白和GSNO还原酶，分别），我们测量了NO和GSNO对细胞生长和蛋白质结合的NO物种的形成的单独和组合的影响。我们的结果表明NO和GSNO之间的细胞内平衡，部分依赖于细胞催化的NO从GSNO释放（即，“SNO-裂解酶”活性）。然而，尽管NO诱导多种类型的基于蛋白质的修饰，其水平与细胞生长的抑制相关，GSNO主要影响蛋白质S-亚硝基化，并且S-亚硝基化与亚硝化应激之间的关系更为复杂。这些数据支持蛋白质-SNO的多个类别的想法，可能反映在不同的合成和降解途径中。事实上，一个显着的分数蛋白质S-亚硝基化的NO发生在不存在的O，这是通常假定驱动这个反应，但相反，显然是在很大程度上依赖于蛋白质结合的过渡金属。此外，我们的研究结果表明，亚硝化应激主要是通过蛋白质靶点子集的S-亚硝基化介导的，其中包括对细胞谷胱甘肽稳定的蛋白质SNO（因此不被GSNO还原酶代谢）。这些结果为NO和GSNO介导亚硝化应激的机制以及涉及金属蛋白、SNO裂解酶和GSNO还原酶的蛋白质S-亚硝基化和脱亚硝基化的细胞途径提供了新的证据。
Nitrosative stress is induced by pathophysiological levels of nitric oxide (NO) and S-nitrosothiols (e.g., S-nitrosoglutathione, GSNO) and arises, at least in significant part, from the nitrosylation of critical protein Cys thiols (S-nitrosylation) and metallocofactors. However, the mechanisms by which NO and GSNO mediate nitrosative stress are not well understood. Using yeast Saccharomyces cerevisiae strains lacking NO- and/or GSNO-consuming enzymes (flavohemoglobin and GSNO reductase, respectively), we measured the individual and combined effects of NO and GSNO on both cell growth and the formation of protein-bound NO species. Our results suggest an intracellular equilibrium between NO and GSNO, dependent in part on cell-catalyzed release of NO from GSNO (i.e., "SNO-lyase" activity). However, whereas NO induces multiple types of protein-based modifications, levels of which correlate with inhibition of cell growth, GSNO mainly affects protein S-nitrosylation, and the relationship between S-nitrosylation and nitrosative stress is more complex. These data support the idea of multiple classes of protein-SNO, likely reflected in divergent routes of synthesis and degradation. Indeed, a significant fraction of protein S-nitrosylation by NO occurs in the absence of 0,, which is commonly assumed to drive this reaction but instead is apparently dependent in substantial part upon protein-bound transition metals. Additionally, our findings suggest that nitrosative stress is mediated principally via the S-nitrosylation of a subset of protein targets, which include protein SNOs that are stable to cellular glutathione (and thus are not metabolized by GSNO reductase). Collectively, these results provide new evidence for the mechanisms through which NO and GSNO mediate nitrosative stress as well as the cellular pathways of protein S-nitrosylation and denitrosylation involving metalloproteins, SNO lyase(s) and GSNO reductase.