Resolving the differential distribution of structural proteins in baculovirus using single-molecule localization microscopy.

Baculovirus is one of the most complex viruses found in nature. Proteomic analysis of budded viruses (BVs) indicates that they are formed by at least 50 different structural proteins. The function of most of these structural proteins and their specific localization in individual virions remain unknown. In the present study, we have conducted single-molecule localization microscopy analysis of the spatial distribution of the nucleocapsid protein P24 and the envelope proteins GP64 and E25. Our results show that P24 and GP64 are polarized to one end of the baculovirus, while E25 distributes more homogenously along the viral envelope. This is the first study using optical microscopy to demonstrate the polarized distribution of structural proteins in individual baculoviruses.