THE MOLECULAR DEFENSES AGAINST REACTIVE OXYGEN SPECIES IN YEAST

There is rapidly expanding interest into the protective systems agains t reactive oxygen species (ROS) in the eukaryotic cell, now that the l inks between oxidative damage, various disease states, and ageing, are firmly established in higher organisms. Yeast molecular genetics shou ld be able to provide powerful insight into these mechanisms; this pot ential is now starting to be exploited. A number of primary antioxidan t activities and systems of metal-ion homeostasis or detoxification ha ve now been demonstrated to contribute to oxidative-stress protection in yeast. Also, evidence is emerging that the oxidative-stress respons e of this organism is complex, involving separate transcription-factor responses to peroxide, superoxide anion and metal ions.