Regulation of alternative oxidase 1 in Chlamydomonas reinhardtii during sulfur starvation.

The mitochondrial respiratory chain in plants, some protists and many fungi consists of the ATP-coupling cyanide-sensitive cytochrome pathway and the cyanide-resistant alternative respiratory pathway. The alternative pathway is mediated by alternative oxidase (AOX). Although AOX has been proposed to play essential roles in nutrient stress tolerance of plants and protists, the effects of sulfur (S) deprivation, on AOX are largely unknown.

Regulation of sulfur deprivation-induced expression of the ferredoxin-encoding FDX5 gene Chlamydomonas reinhardtii in aerobic conditions.

The unicellular green alga Chlamydomonas reinhardtii reacts to sulfur (S) starvation with the increased expression of numerous genes. One gene which is induced in illuminated anaerobic S-deprived cells is the ferredoxin-5 gene (FDX5). To test FDX5 transcriptional regulation in aerobic cultures, we used a real-time PCR analysis and an artificial microRNA approach.

Nitric oxide upregulates expression of alternative oxidase 1 in Chlamydomonas reinhardtii.

The mitochondrial respiratory chain in plants, many fungi and some protists consists of the ATP-coupling cyanide-sensitive cytochrome pathway and the cyanide-resistant alternative respiratory pathway. The alternative pathway is mediated by alternative oxidase (AOX). In unicellular algae, AOXs are monomeric fungi-type proteins.

New insights into AOX2 transcriptional regulation in Chlamydomonas reinhardtii.

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.