Understanding the interaction between Dengue virus and mosquito C-type lectins on the molecular level (360G-Wellcome-204703_Z_16_Z)

The mosquito-borne virus Dengue constitutes an enormous burden on global human health. It is transmitted through the bite of the yellow fever mosquito Aedes aegypti. Recent studies have identified a family of proteins termed mosGCTLs that bind Dengue and promote infection of the mosquito. This attachment has been associated with an interaction between mosGCTLs and Dengue glycan moieties. I will elucidate, at the molecular level, how mosGCTL proteins recognize and attach to Dengue and can thus facilitate infection enhancement. This will be addressed structurally at atomic resolution (via crystallography and cryo-EM) and in the whole organism through validation in live mosquitoes. Key goals: (1) Elucidation of which carbohydrates are bound by mosGCTLs using microarray screening, followed by co-crystallization and structure solution. (2) Biophysical and structural characterization of the interaction between mosGCTLs and Dengue glycoproteins as well as whole virus. Here, I will make use of in vitro binding assays, providing a quantitative readout of interaction strengths. (3) Cryo-EM single particle reconstruction of Dengue virus decorated with mosGCTL proteins to gain a holistic view of attachment to the icosahedral virus. (4) Functional targeted mutagenesis studies with Aedes aegypti mosquitoes to investigate how our molecular level data translates into nature.