Role of protein kinase C δ in reactivation of Kaposi's sarcoma-associated herpesvirus

TPA (12-O-tetradecanoylphorbol-13-acetate), a well-known activator of protein kinase C (PKC), can experimentally induce reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV) in certain latently infected cells. We selectively blocked the activity of PKC isoforms by using GF 109203X or rottlerin and demonstrated that this inhibition largely decreased lytic KSHV reactivation by TPA. Translocation of the PKCδ isoform was evident shortly after TPA stimulation. Overexpression of the dominant-negative PKCδ mutant supported an essential role for the PKCδ isoform in virus reactivation, yet overexpression of PKCδ alone was not sufficient to induce lytic reactivation of KSHV, suggesting that additional signaling molecules participate in this pathway.