INTERCELLULAR TRAFFICKING OF VP22-GFP FUSION PROTEINS IS NOT OBSERVEDIN CULTURED-MAMMALIAN-CELLS

Herpes simplex virus type 1 (HSV-1) VP22 was recently reported to medi ate intercellular trafficking of a protein fused to the C-terminus of VP22. To explore the application of such trafficking, we constructed p lasmids expressing green fluorescent protein (GFP) fused to the C-term inus of either wild-type VP22 or a 160 amino acid peptide from VP22. I n vitro studies showed that the majority of both fused proteins were l ocalized to the nuclei of transfected cells. Quantitative analysis of GFP-positive cells, however, showed no significant increase in interce llular protein trafficking for cells transfected with either fusion pr otein compared with a lacZ-expressing plasmid. Our results suggest tha t the use of HSV-1 VP22 for mediating intercellular trafficking of tra nsgene products is limited.