Source: http://cegg.uniige.ch/insecta/immunodb

SODs: Superoxide Dismutatses
Summary

Carolina Barillas Mury 

Laboratory of Malaria and Vector Research, Twinbrook III Facility, NIAID, NIH, USA 

Reactive Oxygen Species and Immunity 
Superoxide anion (?O2-) is generated by NADPH oxidase as part of the oxidative burst in activated macrophages. Superoxide dismutases (SODs) convert ?O2- into hydrogen peroxide (H2O2), a less toxic product. Eukaryotic MnSODs are typically nuclear-encoded mitochondrial enzymes, while Cu/ZnSODs are cytosolic. These two SOD classes appear to have evolved independently, as they share no sequence homology. MnSODs are single copy genes in Dm and Ag, but Aa has a second gene that appears to be diverging faster than the ancestral one. There are three Cu/Zn SODs with one-to-one orthologues in mosquitoes and Dm. Interestingly, the AgSOD3a and AgSOD3b transcripts are products of a single gene that share a common N-terminal exon and differ in their second exon, which codes for the catalytic domain. This duplication of the second exon in SOD3 is unique to mosquitoes.