Human-herpesvirus-8-encoded k8 protein colocalizes with the promyelocytic leukemia protein (PML) bodies and recruits p53 to the PML bodies

Promyelocytic leukemia protein (PML) bodies are nuclear sites for both inpu t viral genome deposition and immediate-early (IE) gene transcription durin g infection with certain human DNA viruses, such as human cytomegalovirus ( HCMV), herpes simplex virus type 1, and adenovirus, In this study, we showe d that the K8 (K-bZIP) protein, an early protein encoded by the human herpe svirus 8 (HHV-8), colocalized with the PML bodies in HHV-8-infected primary effusion lymphoma cells. Cotransfection of two plasmids expressing the K8 protein and green-fluorescence protein (GFP)-PML fusion protein into 293T c ells revealed that the K8 protein colocalized with PML in cells with high P ML expression. Overexpression of the K8 protein in Chinese hamster ovary (C HO) cells with stable GFP-PML expression did not induce the dispersion of t he PML bodies, unlike the IE1 protein of HCMV. Transfection of a truncated K8 gene revealed that the leucine zipper domain of the KS protein was requi red for the colocalization with PML We also demonstrated that the K8 protei n bound to p53 in vivo and in vitro. and that high expression of the K8 pro tein caused the accumulation of p53 to the PML bodies in CHO cells, suggest ing that the K8 protein functions In the recruitment of p53 to the PML bodi es, These data suggest that the K8 protein may be associated with the funct ional modulation of p53 in the nucleus during the lytic phase of HHV-8. (C) 2001 Academic Press.