Effects of a transition from normoxia to anoxia on yeast cytochrome c oxidase and the mitochondrial respiratory chain: implications for hypoxic gene induction.

摘要: Abstract Previous studies have demonstrated that the mitochondrial respiratory chain and cytochrome c oxidase participate in oxygen sensing induction of some hypoxic nuclear genes eukaryotes. In addition, it has been proposed mitochondrially-generated reactive nitrogen species function as signals a signaling pathway for genes. To gain insight concerning this pathway, we looked at changes functionality yeast cells experience shift from normoxia to anoxia. These revealed retain ability respire normoxic levels up 4 h after drop rapidly 30–50% their turnover rate (COX) increases during shift. The increase COX cannot be explained by replacing aerobic isoform, Va, subunit V with more active Vb. We also found mitochondria respire, albeit reduced levels, anoxic cells, indicating maintain functional absence oxygen. This raises intriguing possibility previously unexplored role may an alternative electron acceptor when is unavailable.