Cytochrome c is released from coupled mitochondria of yeast en route to acetic acid‐induced programmed cell death and can work as an electron donor and a ROS scavenger

To gain insight into the processes by which acetic acid‐induced programmed cell death (AA‐PCD) takes place in yeast, we investigated both cytochrome c release from yeast mitochondria and mitochondrial coupling over the time course of AA‐PCD. We show that the majority of cytochrome c release occurs early in AA‐PCD from intact coupled mitochondria which undergo only gradual impairment. The released cytochrome c can be reduced both by ascorbate and by superoxide anion and in turn be oxidized via cytochrome c oxidase, thus working both as a ROS scavenger and a respiratory substrate. Late in AA‐PCD, the released cytochrome c is degraded.