Abstract
Superoxide dismutase (SOD) is one of several major proteins that regulate removal of superoxide. Three isoforms of SOD exist in mammals. It has long been thought that Drosophila lacks the SOD3 gene. However, a putative SOD3 gene sequence (dSod3) in the Drosophila genome was reported recently. Thus we investigated whether dSod3 truly functions as a SOD3 homolog in Drosophila. We found that dSod3 not only retains SOD activity but also properties of secreted proteins, as do other SOD3s. In addition, the dSod3 protein alleviates ultraviolet-induced cellular damage. These results suggest that dSod3 functions as an extracellular SOD3.
