Baculovirus O-glycosylated Protein GP41 Regulates Virus Assembly Mechanism

Posted by Chelsea Clark on June 15th, 2018

Recently, a paper entitled the functional oligomeric state of tegument protein GP41 is essential for baculovirus BV and ODV assembly being published on the Journal of Virology, revealing the mechanism of baculovirus O-glycosylated protein GP41 regulating viral particle assembly.

Baculovirus is a type of large DNA virus that specifically infects insects and forms two different types of progeny virus particles in its infection cycle - budding virus particle BV and embedded virus particle ODV. The virus infects cells and then replicates and assembles in the nucleus to form a nucleocapsid, a portion of the nucleocapsids are transported through the nuclear membrane to the cell membrane to form a BV, the other part of the nucleocapsid remains assembled in the nucleus into ODV, but the assembly mechanism of BV and ODV is not yet clear.

O-glycosylation is a ubiquitous protein modification in the biosphere, which usually plays an important role in regulating receptor binding, protein transport, signal transduction, and nuclear pore complex formation. And the formation of cytoskeleton and other processes. However, the function of the virus O-glycosylated protein is still not clear. GP41 is the only O-glycosylated protein currently found in baculoviruses. Studies have shown that it is rich in O-glycosylation, and is mainly located in the cortex between the capsule and nucleocapsid of ODV.

Previous studies have shown that GP41 is involved in the nuclear transport of baculovirus nucleocapsid so that it is very important for BV formation, while GP41 is one of the major components of ODV, but it is unclear whether it participates in the formation of ODV. Researchers have elucidated the role of the O-glycosylated viral protein GP41 in the proliferation of baculoviruses for the first time. The study found that GP41 is involved in the nuclear translocation of BV nucleocapsid and it plays an important role in the formation of ODV by the interaction of the nucleocapsid and microvesicles. The deletion of the gp41 gene will result in the inability of BV and ODV formation.

Meanwhile, GP41 forms oligomers during infection in which trimers are specifically packaged into progeny virions BV and ODV, presumably as a functional form of GP41. It was further found that the disulfide bond and leucine zipper are the key structural sites for the formation of oligomers by GP41.

This study provides an important basis for further analysis of the role of baculovirus O-glycosylated protein GP41 in viral infection and the mechanism of virus assembly. We will look forward to the further application of this study, and update the further information and details for you.