Stress in the powerhouse of the cell
The aggregation observed by the researchers could cause the cell powerhouses to stop working, but all organisms require this activity for survival. To counteract these defects the cells execute what the researchers call a protective stress response, which enables mitochondria to maintain their key functions. By means of this stress response, cells such as baker’s yeast — the model organism used to carry out the researchers’ experiments — survive. Along with doctoral candidate and lead author of the study, Daniel Poveda-Huertes, Vögtle also discovered that the regulation of many different genes is happening in the cell nucleus. What is more, the researchers found out that a transcription factor normally found in the nucleus was surprisingly transported into the mitochondria, where the expression of genetic information was enhanced. Only through this mechanism could the mitochondria ensure cell survival by maintaining generation of energy under these stressful conditions. This completely novel principle in the stress response of cells, explains Vögtle, is probably the earliest reaction that has been detected up until now. She says, “That’s the cell’s first line of defense when stress appears in its powerhouses.”