Ostroukhova Mariya, Zalutskaya Zhanneta, Ermilova Elena
Biological Faculty, Saint-Petersburg State University, Universitetskaya nab. 7/9, Saint-Petersburg 199034, Russia.
Biological Faculty, Saint-Petersburg State University, Universitetskaya nab. 7/9, Saint-Petersburg 199034, Russia.
Eur J Protistol. 2017 Apr;58:1-8. doi: 10.1016/j.ejop.2016.11.005. Epub 2016 Dec 13.
A feature of the mitochondrial electron transport chain in plants, some protists and many fungi is the presence of two terminal oxidases, the energy-conserving cytochrome oxidase and another termed alternative oxidase (AOX). AOX branches from the main respiratory chain, directly coupling the oxidation of ubiquinol with reduction of oxygen to water. The AOX genes can be divided into two discrete subfamilies, AOX1 and AOX2. Although AOX has been proposed to play essential roles in stress tolerance of organisms, the role of subfamily AOX2 is largely unknown. In the model green alga Chlamydomonas reinhardtii, two genes have been identified that encode for AOX, AOX1 and AOX2. To test AOX2 transcriptional regulation in this alga, we used a real-time PCR analysis and an artificial microRNA approach. The C. reinhardtii AOX2 gene is up-regulated by oxygen or copper deprivation. Moreover, in dark-adapted unstressed cells, AOX2 is induced. Together, our results imply that the AOX2 gene is a stress-inducible and is regulated by the copper response regulator 1 (CRR1), probably together with yet-unknown regulatory factor(s).
植物、一些原生生物和许多真菌的线粒体电子传递链的一个特点是存在两种末端氧化酶，即能量保守型细胞色素氧化酶和另一种称为交替氧化酶（AOX）的酶。AOX从主要呼吸链分支出来，直接将泛醇的氧化与氧气还原为水的过程偶联起来。AOX基因可分为两个不同的亚家族，AOX1和AOX2。尽管有人提出AOX在生物体的胁迫耐受性中起重要作用，但AOX2亚家族的作用在很大程度上尚不清楚。在模式绿藻莱茵衣藻中，已鉴定出两个编码AOX的基因，AOX1和AOX2。为了测试该藻类中AOX2的转录调控，我们使用了实时PCR分析和人工microRNA方法。莱茵衣藻AOX2基因在缺氧或缺铜时上调。此外，在黑暗适应的未受胁迫细胞中，AOX2也被诱导。总之，我们的结果表明AOX2基因是一种胁迫诱导型基因，受铜反应调节因子1（CRR）调控，可能还与其他未知的调节因子共同作用。
