Identification and characterization of prohibitin as a receptor protein mediating DENV-2 entry into insect cells

Dengue is transmitted primarily by mosquitoes of the Aedes genus. Despite a number of studies, no insect dengue virus receptor protein has been clearly identified and characterized. Using a number of separation methodologies and virus overlay protein binding assays we identified a 35 kDa protein that segregated with susceptibility to dengue serotype 2 (DENV-2) infection in two mosquito species and two mosquito cell lines. Mass spectroscopy identified the protein to be prohibitin, a strongly conserved and ubiquitously expressed protein in eukaryotic cells. Antibody mediated inhibition of infection and siRNA mediated knockdown of prohibitin expression significantly reduced infection levels and subsequent virus production in both Aedes aegypti and Aedes albopictus cell lines. Confocal microscopy showed a significant degree of intracellular colocalization between prohibitin and DENV-2 E protein, and coimmunoprecipitation confirmed that prohibitin interacts with dengue E. Prohibitin is the first characterized insect cell expressed dengue virus receptor protein.