Oxygen-independent induction of enzyme activities related to oxygen metabolism in yeast by copper.
Aerobic growth of Saccharomyces cerevisiae in the presence of CuSO4 (between 0.1 and 1 mM) caused a generalized induction of major enzyme activities involved in 'housekeeping' routes of oxygen metabolism (cytochrome oxidase, glutathione peroxidases and catalase) which were comparable to or higher than that observed with Cu,Zn-superoxide dismutase. Fumarase and glutathione transferase, tested as controls for oxygen-unrelated activities, were found to decrease under the same conditions. In the absence of oxygen, copper addition to yeast resulted in significant increases of Cu,Zn-superoxide dismutase and glutathione peroxidases and a slight increase of cytochrome oxidase, with catalase remaining undetectable irrespective of whether or not copper was present. Other metal ions tested (Mn2+, Co2+) were unable to produce such effects. It is concluded that copper has a general inducing effect on enzymes related to metabolism of oxygen and oxygen derivatives, which is mediated neither by formation of O2-. and H2O2 nor by interaction with copper-specific apoproteins. These results point to a general role of copper as regulator of the expression of major enzyme activities involved in biological oxygen activation.
Galiazzo
F
F
Department of Biology, Tor Vergata University, Rome, Italy.
Schiesser
A
A
Rotilio
G
G
D000332:Aerobiosis; D000693:Anaerobiosis; D002374:Catalase / Q000096:biosynthesis; D003300:Copper / Q000494:pharmacology*; D003576:Electron Transport Complex IV / Q000096:biosynthesis; D004790:Enzyme Induction / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000096:biosynthesis; D010100:Oxygen / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D012643:Selenium / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000096:biosynthesis
D003300:Copper; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D003576:Electron Transport Complex IV; D012643:Selenium; D010100:Oxygen