MOLECULAR MECHANISMS OF DENGUE VIRUS FUSION AND GENOME REPLICATION

Abstract

This thesis focuses on elucidating the molecular mechanisms of DENV genome replication and fusion, essential early stages of the virus life cycle. I examined DENV capsid protein (DENV2C) as an RNA chaperone in the annealing and strand displacement of RNA elements at 5’ and 3’ ends of the genome during genome replication, by tracking reactions in real-time using FRET pairs labelled on RNA. DENV2C was found to accelerate annealing and promote strand displacement of RNA sequences in solution, providing mechanistic insights by which DENV2C chaperones the interactions between RNA elements at the 5’ and 3’ ends during genome rearrangement. Upstream of genome replication, fusion kinetics was studied using a single-virus fusion assay. The assay showed that DENV2 fusion efficiency decreases by 4-fold at pH 7 compared to at pH 5.3, and by 3-fold in the presence of SIgN-3C antibodies at pH 5.3.