Functional Roles Of Host Cellular ESCRT-I Complex In AcMNPV Budded Virions Infection

In eukaryotic cells, the endosomal sorting complex required for transport (ESCRT) iscomposed of ESCRT-0, I, II, III, and Vps4complexes which is required for recognition andsorting of ubiquitilated membrane proteins, which will be trafficking to lysosomes forselective destruction. ESCRT is also involved in autophage and cytokinesis. In addition,cellular ESCRT is also essential for efficient entry and budding of some enveloped viruses.The Baculoviridae is a family of enveloped, double-stranded DNA viruses. Baculoviruses arewildly used as bio-insecticides, for foreign genes expression and display, and for transducingmammalian cells. The prototype and most intensively studied baculovirus is analphabaculovirus, Autographa californica multiple nucleopolyhedrovirus (AcMNPV). Recentstudies revealed that cellular Vps4, the key regulator of ESCRT system, is required forefficient entry and egress of budded virions of Autographa californica multiplenucleopolyhedrovirus (AcMNPV) from host cells; however, the detailed mechanism ofESCRT involved in baculoviruses infection is unknown. In this thesis, we focused on therole(s) of ESCRT-I in AcMNPV infection. Initially, we obtained the full-length open readingframe (ORF) of the ESCRT-I components, Tsg101, Vps28, Vps37A, and Vps37B.Bimolecular fluorescence complementation (BiFC) assay revealed the interaction of Tsg101and Vps28. Transient overexpression of Tsg101or the truncated forms of Tsg101(absent ofUEV, proline-rich, coiled-coil, or steadless box domain) significantly reduced the productionof infectious budded virions of AcMNPV. The detailed role(s) of ESCRT-I in AcMNPVinfection is still under investigating.