Aedes aegypti peroxidase gene characterization and developmental expression

The functions of insect peroxidases include detoxification, stabilization o f extracellular matrices, and possible involvement in insect immunity. The current study describes the isolation of a peroxidase gene, AePox, and its cDNA from the mosquito, Aedes aegypti. AePox codes for a protein that is ho mologous to various heme-peroxidases from vertebrates and invertebrates, wi th highest identity to Drosophila melanogaster peroxidase (62%). Sequence c omparison identified several functionally and structurally conserved domain s in the mosquito peroxidase, including a heme environment, a calcium bindi ng site, and five possible disulfide bridges. These results imply that AePO X may likely have a similar structure and catalytic mechanism as those desc ribed for the mammalian myeloperoxidase superfamily. Expression studies dem onstrate that AePox is transcribed in mosquito larvae and pupae, but not in adults, in ovaries, or in early embryos. However, AePOX protein is present in all mosquito stages and possibly has a maturation process that is simil ar to that of human myeloperoxidase. Unlike most human peroxidases, the AeP ox gene contains a TATA box and an ecdysone response element (EcRE). (C) 20 01 Elsevier Science Ltd. All rights reserved.