Glutathione and gamma-glutamyl transferases are involved in the formation of cadmium-glutathione complex.
In a wild-type strain of Saccharomyces cerevisiae, cadmium induces the activities of both gamma-glutamyl transferase (gamma-GT) and glutathione transferase 2 (Gtt2). However, Gtt2 activity did not increase under gamma-GT or Ycf1 deficiencies, suggesting that the accumulation of glutathione-cadmium in the cytosol inhibits Gtt2. On the other hand, the balance between the cytoplasmic and vacuolar level of glutathione seems to regulate gamma-GT activity, since this enzyme was not activated in a gtt2 strain. Taken together, these results suggest that gamma-GT and Gtt2 work together to remove cadmium from the cytoplasm, a crucial mechanism for metal detoxification that is dependent on glutathione.
Dep. Bioquímica, IQ, UFRJ, 21941-909 Rio de Janeiro, Brazil.
Paula Daniela Braga
PD
Adamis
Sérgio Cantú
SC
Mannarino
Elis Cristina Araújo
EC
Eleutherio
D002104:Cadmium / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*
D002104:Cadmium; D005723:gamma-Glutamyltransferase; D005982:Glutathione Transferase; D005978:Glutathione