Carbonic anhydrase isozyme CA3 protects cells against oxidative stress. Ectopic expression of murine Ca3, but not Ca2, protects proto-oncogene Evi1 expressing Rat1 fibroblast cells (ca3 low) against hydrogen peroxide (H2O2) induced stress. Ca3 is S-glutathionylated via glutathione adducts with cysteines 181 and 186. Substitution of both Ca3 cysteines with serine fails to protect cells from oxidative stress. Insertion of cysteine at 181 and 186 in Ca2 is insufficient for conferring efficient anti-oxidant activity. This shows for the first time that S-glutathionylation of cys181 and cys186 residues are required for Ca3 anti-oxidant activity but that additional factors are also required.
- Carbonic anhydrase III