Construction of a Series of C-terminal Truncation Mutants of Pseudorabies Virus VP22 and Their Subcellular Localization

To study the specific subcellular localization of different regions of Pseudorabies virus (PrV) VP22, a series of mutants with the C-terminal truncations were amplified from a plasmid containing the full-length VP22 gene of the Ea strain. The resulting truncation constructs were fused to ORF encoding the green fluorescent protein (GFP) to generate eukaryotic expression plasmids expressing VP22 mutants and GFP fusion proteins. HeLa cells were transiently transfected with these fusion expression plasmids. By detecting the GFP fluorescence localization, several potential regions of PrV VP22 for specific subcellular localization were determined as follows: 60-90 amino acids (aa) of VP22 are required for nuclear targeting; 111-159 aa may be involved with the formation of particles in the nucleus; 187-241 aa are needed for binding to microtubules. These results lay foundation for further study on the structure and function of PrV VP22.