Shi F, et al. (2011) Role of mitochondrial NADH kinase and NADPH supply in the respiratory chain activity of Saccharomyces cerevisiae. Acta Biochim Biophys Sin (Shanghai) 43(12):989-95
Abstract: In Saccharomyces cerevisiae, the mitochondrial nicotinamide adenine dinucleotide hydride kinase Pos5p is required for a variety of essential cellular pathways, most importantly respiration. The Pos5p knockout strain pos5? grows poorly in non-fermentable media. A potential relationship between this respiratory deficiency and the ability of the cells to supply nicotinamide adenine dinucleotide phosphate (NADPH) was examined by analyzing the respiratory chain activity of pos5? and two NADP(+)-specific dehydrogenase mutants, idp1? and zwf1?. All of the respiratory chain complexes of pos5? exhibited poor relative activity of <26% at the middle-log phase and 62% at the stationary phase. The respiratory chain activity levels of idp1? and zwf1? also reduced to 22%-37% and 28%-84% at the middle-log phase, and 73%-81% and 67%-88% at the stationary phase, not as robustly as those of pos5?. The double-mutant idp1pos5? exhibited even lower activities of <20% at the middle-log phase, but zwf1pos5? showed similar activities with pos5?. The complemented strain POS5/pos5? exhibited 1.05- to 3-fold higher activities than pos5?. These data showed that Pos5p contributes to the maintenance of respiratory chain complex activities, with other NADPH sources, such as Idp1p and Zwf1p, making a smaller contribution. These contributions were partly related to the ability of the cells to supply NADPH, especially in the mitochondria.
|Status: Published||Type: Journal Article||PubMed ID: 22011405|
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Number of different genes curated to this paper: 3
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