INTERCELLULAR TRAFFICKING AND PROTEIN DELIVERY BY A HERPESVIRUS STRUCTURAL PROTEIN

We show that the HSV-1 structural protein VP22 has the remarkable prop erty of intercellular transport, which is so efficient that following expression in a subpopulation the protein spreads to every cell in a m onolayer, where it concentrates in the nucleus and binds chromatin. VP 22 movement was observed both after delivery of DNA by transfection or microinjection and during virus infection. Moreover, we demonstrate t hat VP22 trafficking occurs via a nonclassical Golgi-independent mecha nism. Sensitivity to cytochalasin D treatment suggests that VP22 utili zes a novel trafficking pathway that involves the actin cytoskeleton. In addition, we demonstrate intercellular transport of a VP22 fusion p rotein after endogenous synthesis or exogenous application, indicating that VP22 may have potential in the field of protein delivery.