Functional Analysis of AcMNPV P78/83 Protein

Autographa californica nucleopolyhedrovirus (AcMNPV) is the typical member of nucleopolyhedrovirus of Baculoviradae, a circled and double stranded large DNA virus. It’s also one of the most widely studied baculoviruses that turns out to be environment sound pesticide and a powerful vector of foreign protein expression as well as a promising vector of gene therapy. Revealing the molecular mechanism of the interaction plays a key role in the better understanding of viral replication, package, transportation and application of baculovirus as a gene therapy vector. Sequence analysis found that the P78/83 product of AcMNPV ORF9 shares the common motifs with WASP proteins indicating that P78/83 might involve in baculovirus transportation. Trying to understand P78/83 function, we constructed a recombinant virus vAc-orf9-gfp with the Bac-to-Bac system, within which AcMNPV ORF9 was fused with enhanced green fluorescence protein (EGFP). Sf21 cells were infected with the recombinant virus and Laser Confocal Microscopy was used to determine the subcellular location of P78/83. Green fluorescences showed major distribution in cell plasm a after 12h infection, and transfered into nucleus at 24 hpi. This means that P78/83 is located in the nucleus. Infection assay in vitro showed that overexpression of P78/83 had no effect on virus growth and viral assembly.