Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Bogor, Indonesia.
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan.
Adv Microb Physiol. 2018;72:29-63. doi: 10.1016/bs.ampbs.2018.01.003. Epub 2018 Mar 2.
Nitric oxide (NO) is a cellular signalling molecule widely conserved among organisms, including microorganisms such as bacteria, yeasts, and fungi, and higher eukaryotes such as plants and mammals. NO is mainly produced by the activities of NO synthase (NOS) or nitrite reductase (NIR). There are several NO detoxification systems, including NO dioxygenase (NOD) and S-nitrosoglutathione reductase (GSNOR). NO homeostasis, based on the balance between NO synthesis and degradation, is important for regulating its physiological functions, since an excess of NO causes nitrosative stress due to the high reactivity of NO and NO-derived compounds. In yeast, NO may be involved in stress responses, but the role of NO and the mechanism underlying NO signalling are poorly understood due to the lack of mammalian NOS orthologs in the yeast genome. NOS and NIR activities have been observed in yeast cells, but the gene-encoding NOS and the mechanism by which NO production is catalysed by NIR remain unclear. On the other hand, yeast cells employ NOD and GSNOR to maintain intracellular redox balance following endogenous NO production, treatment with exogenous NO, or exposure to environmental stresses. This article reviews NO metabolism (synthesis, degradation) and its regulation in yeast. The physiological roles of NO in yeast, including the oxidative stress response, are also discussed. Such investigations into NO signalling are essential for understanding how NO modulates the genetics and physiology of yeast. In addition to being responsible for the pathology and pharmacology of various degenerative diseases, NO signalling may be a potential target for the construction and engineering of industrial yeast strains.
一氧化氮（NO）是一种在生物体中广泛保守的细胞信号分子，包括细菌、酵母和真菌等微生物，以及植物和哺乳动物等高等真核生物。NO 主要由一氧化氮合酶（NOS）或亚硝酸盐还原酶（NIR）产生。有几种 NO 解毒系统，包括一氧化氮双加氧酶（NOD）和 S-亚硝基谷胱甘肽还原酶（GSNOR）。基于 NO 合成和降解之间的平衡的 NO 动态平衡对于调节其生理功能很重要，因为过量的 NO 会由于 NO 和 NO 衍生化合物的高反应性而导致硝化应激。在酵母中，NO 可能参与应激反应，但由于酵母基因组中缺乏哺乳动物 NOS 同源物，NO 的作用及其信号转导机制尚不清楚。已经在酵母细胞中观察到 NOS 和 NIR 活性，但编码 NOS 的基因以及 NIR 催化 NO 产生的机制仍不清楚。另一方面，酵母细胞采用 NOD 和 GSNOR 在体内产生 NO 后、用外源性 NO 处理或暴露于环境应激时，维持细胞内氧化还原平衡。本文综述了酵母中 NO 的代谢（合成、降解）及其调控。还讨论了 NO 在酵母中的生理作用，包括对氧化应激的反应。对 NO 信号转导的此类研究对于理解 NO 如何调节酵母的遗传学和生理学至关重要。除了负责各种退行性疾病的病理学和药理学外，NO 信号转导可能是构建和工程化工业酵母菌株的潜在目标。
