title: New insights into AOX2 transcriptional regulation in Chlamydomonas reinhardtii.
abstract: 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).
authors.affiliation: Biological Faculty, Saint-Petersburg State University, Universitetskaya nab. 7/9, Saint-Petersburg 199034, Russia.
authors.forename: Mariya
authors.initials: M
authors.lastname: Ostroukhova
authors.affiliation: Biological Faculty, Saint-Petersburg State University, Universitetskaya nab. 7/9, Saint-Petersburg 199034, Russia.
authors.forename: Zhanneta
authors.initials: Z
authors.lastname: Zalutskaya
authors.affiliation: Biological Faculty, Saint-Petersburg State University, Universitetskaya nab. 7/9, Saint-Petersburg 199034, Russia. Electronic address: e.ermilova@spbu.ru.
authors.forename: Elena
authors.initials: E
authors.lastname: Ermilova
mesh_terms: D016825:Chlamydomonas reinhardtii / Q000201:enzymology* / Q000235:genetics*; D003300:Copper / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D035683:MicroRNAs / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological / Q000235:genetics*; D000099188:Alternative Oxidase
chemical_list: D003300:Copper; D035683:MicroRNAs; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010100:Oxygen; D010940:Plant Proteins; D000099188:Alternative Oxidase
keywords: Alternative oxidase; Anoxia; Artificial microRNA approach; Chlamydomonas reinhardtii; Copper deprivation; Quantitative real-time RT-PCR