ND10 PROTEIN PML IS RECRUITED TO HERPES-SIMPLEX VIRUS TYPE-1 PREREPLICATIVE SITES AND REPLICATION COMPARTMENTS IN THE PRESENCE OF VIRAL-DNAPOLYMERASE

Herpes simplex virus type 1 (HSV-1) infection results in the disruptio n of ND10 (also called nuclear bodies, PODs, or PML-associated bodies) , which are nuclear matrix domains of unknown function present in mamm alian cells. After ND10 disruption, viral transcription and DNA replic ation occur in globular nuclear domains called replication compartment s. In this report we define four stages of infection by using antibodi es to ICP8 (also called SSB and UL29) and the ND10 antigen PML. Immedi ately after infection, cells contain intact ND10 as detected by staini ng for PMLs (stage I); within 1 hour, however, ND10 are disrupted and cells begin to exhibit diffuse staining for the major viral DNA bindin g protein, ICPS (stage II). After all ND10 have been disrupted, foci w hich resemble but are not equivalent to ND10 appear, containing both P ML and ICPS (stage III). Cells infected with mutants defective in the helicase-primase or origin binding protein are unable to form stage II I foci. Cells infected with a mutant that is null for the polymerase c atalytic subunit, however, form stage III-like ICP8 foci which do not contain PML. Thus, stage III foci recruit the cellular PML protein in the presence but not the absence of HSV polymerase. PML was recruited to stage III foci in some but not all cells infected with a mutant def ective in the polymerase accessory protein, UL42. Thus, UL42 is not re quired for the recruitment of PML to viral foci. In wild-type infectio n, stage III cells are quickly replaced by cells containing replicatio n compartments (stage IV). PML and ICPS staining are both observed wit hin replication compartments, indicating a potential role for PML in H SV-1 replication. Models for the role of ND10 proteins in the formatio n of replication compartments are discussed.