Apparently, under stress the Saccharomyces cerevisiae yeast mitochondria produce reactive oxygen species ROS, leading to loss of membrane potential within the mitochondria and death of the cell. my knowledge of english and biology is a bit rusty, so please explain me this:
Does ROS stay in mitochondria, or can it also go out of the mitochondria? Also, what kind of stress are we talking about (heat...?)?
any type of stress can produce ROS, you'd be surprised how often ROS is released from the mitochondria. stuff like too much light, temperature change, moving cells tooo much, pipetting media too fast into the cells can all cause ROS levels to rise. but the problem is alot of time ROS comes and goes really fast because of natural antioxidants in cells so it's hard to measure ROS levels since they fluctuate at fast rate.
yes ROS can permeate out of the mitochondria and cause signaling cascades in the cytoplasm like turning on inflammatory response pathways.
also ROS isn't only produced by the mitochondria, there are other sources, a good one is NOX enzymes on the plasma membrane of cells: [Only registered users see links. ] ..but i'm not sure if yeast has that