THE HERPES-SIMPLEX VIRUS TYPE-1 TRANSACTIVATOR ICPO MEDIATES ABERRANTINTRACELLULAR-LOCALIZATION OF THE VIRAL HELICASE PRIMASE COMPLEX SUBUNITS/

The infected cell polypeptide O (ICPO) protein of herpes simplex virus type 1 (HSV-1) is a promiscuous transactivator. When expressed by tra nsfection, ICPO forms spherical structures in the nucleus. Using a dou ble-label immunofluorescence assay, we have found that the HSV-1 helic ase/primase complex subunits accumulate within ICPO structures in cotr ansfected cells. This phenomenon was also observed in cells coexpressi ng ICPO and UL6, a protein thought to be involved in the cleavage and/ or packaging of viral genomes. ICPO structures were found to be protei naceous by immunoelectron microscopy. These results suggest that ICPO may interact nonspecifically with a variety of viral proteins. (C) 199 6 Academic Press, Inc.