Wilson, A.; Kamel, W.; Davies, K.; Bell-Sakyi, L.; Lamont, D.; Demyanenko, Y.; Kitano, E.; Noerenberg, M.; Kohl, A.; Mohammed, S.; Castello, A.; Brennan, B.

RNA-binding proteins (RBPs) are pivotal for the viral lifecycle, mediating key host-virus interactions that promote or repress virus infection. While these interactions have been largely studied in the vertebrate host, no comprehensive analyses of protein-RNA interactions occurring in cells derived from the infected vector have been done to date, particularly for ticks. Here we systematically identify the responses of the RNA-binding proteome (RBPome) to infection with a prototype bunyavirus (Uukuniemi virus; rUUKV) in tick cells and discovered changes in RNA-binding activity for 283 proteins. In an orthogonal approach, we analysed the interactions of the viral ribonucleoprotein by immunoprecipitation of UUKV nucleocapsid (NCAP) in infected cells. We found that tick cell derived RBPs are regulated by UUKV and associate with N complexes, suggesting a functional connection with infection. We confirmed experimentally that these RBPs impact UUKV infection, with TOP3B showing a putative effect on viral particle production. Our data thus reveals the first protein-RNA interaction map determined in infected tick cells.