Molecular identification and characterization of aminopeptidase N1 from Anopheles stephensi: A candidate for transmission blocking vaccines

Malaria is still a serious disease, killing hundreds of thousands of people every year. Previous studies on the Aminopeptidase N1 (APN1) protein from Anopheles gambiae (the main malaria vector in Africa) revealed that it is a receptor for sexual stage of Plasmodium falciparum in midgut of this mosquito and can be inhibited by polyclonal antibodies, producing against the N-terminal of this protein. Despite its importance this gene and its protein have not yet been characterized in Anopheles stephensi (the main malaria vector in Eastern Mediterranean Regions and Indochina). In this paper, total cDNA of APN1 from Anopheles stephensi (APN1As) was identified by using Rapid Amplification of cDNA Ends (RACE), real-time PCR was applied to evaluate amount of mRNA level after blood-feeding, and several bioinformatics tools were used for more characterization of identified sequences. Result showed that this protein has highly similarity that of aminopeptidase N1 from Anopheles gambiae, especially in N-terminal part of this protein. Also, expression level of this gene significantly increases after blood-feeding. Therefore, as this gene and its protein have high similarity that APN1Ag, if biological tests confirm, it could be a candidate for transmission blocking vaccines in malaria endemic countries.