Investigations into the antiviral activities and functions of the Aedes aegypti Ago2 protein.

The exogenous siRNA (exo-siRNA) pathway plays an essential role in virus infection control inmosquitoes, including Aedes aegypti, an important vector of arboviruses. This pathway requires the Dicer 2(Dcr2) nuclease that cleaves viral double-stranded RNA into viral siRNAs, and in the next step, theArgonaute 2 (Ago2) protein is a part of the multiprotein RNA-induced silencing complex (RISC), whichtargets and degrades viral siRNA. In this project, we will study the critical antiviral effector protein Ago2 andits modes of action and regulation, and the Ago2 interactions in the presence and absence of SFV4 will beinvestigated. The results showed that Ago2 wild type, Ago2 mutant and eGFP are all expressed in ourstable cell lines (AF525-V5-Ago2wt, AF525-V5-Ago2mut, and AF525-V5-eGFP respectively). We also foundthat the catalytic tetrad is important for antiviral Ago2 activity. Moreover, the interaction of Ago2 withother proteins in the presence and absence of SFV infection is currently being analysed in more detail. SmallRNA sequencing was used to assess which derived small RNAs are bound to Ago2 or the catalyticallyinactive mutant, as the slicer activity is also essential for the turnover of small RNAs in Ago2.