Intercellular Trafficking of VP22, a Herpes Simplex Virus Type 1 Tegument Protein

The herpes simplex virus type 1 (HSV-1) tegument protein, VP22 has been reported to have the property of intercellular transport. The previous studies have shown that following expression of a fusion protein containing VP22 it spreads to every cell in a monolayer and concentrates in the nucleus. In spite of these reports, some studies have shown that VP22 trafficking and its nucleus accumulation is an artifact and no improvement in translocation of proteins fused to VP22 has been detected. Methods: To better understand about VP22 translocation, VP22-GFP (Green Fluorescent Protein) vector was constructed and its nuclear accumulation, transportation to the nontransfected cells and translocation between different cell types were studied by fluorescent microscope. Results: VP22-fusion protein was detected in nontransfected cells which in some of them the fusion protein was shown in nucleus. Conclusion: The results demonstrated that VP22 can easily transport between different cells but nuclear accumulation of the protein is not common in all of the recipient cells.