A conserved family of herpesvirus protein kinases plays a crucial role in herpesvirus DNA replication and virion production. However, despite the fact that these kinases are potential therapeutic targets, no systematic studies have been performed to identify their substrates. We generated an Epstein-Barr virus (EBV) protein array to evaluate the targets of the EBV protein kinase BGLF4. Multiple proteins involved in EBV lytic DNA replication and virion assembly were identified as previously unrecognized substrates for BGLF4, illustrating the broad role played by this protein kinase. Approximately half of the BGLF4 targets were also in vitro substrates for the cellular kinase CDK1/cyclin B. Unexpectedly, EBNA1 was identified as a substrate and binding partner of BGLF4. EBNA1 is essential for replication and maintenance of the episomal EBV genome during latency. BGLF4 did not prevent EBNA1 binding to sites in the EBV latency origin of replication, oriP. Rather, we found that BGLF4 was recruited by EBNA1 to oriP in cells transfected with an oriP vector and BGLF4 and in lytically induced EBV-positive Akata cells. In cells transfected with an oriP vector, the presence of BGLF4 led to more rapid loss of the episomal DNA, and this was dependent on BGLF4 kinase activity. Similarly, expression of doxycycline-inducible BGLF4 in Akata cells led to a reduction in episomal EBV genomes. We propose that BGLF4 contributes to effective EBV lytic cycle progression, not only through phosphorylation of EBV lytic DNA replication and virion proteins, but also by interfering with the EBNA1 replication function.Herpesviruses encode two families of serine/threonine protein kinases, one of which, the BGLF4 (Epstein-Barr virus [EBV])/UL97 (human cytomegalovirus)/UL13 (herpes simplex virus)/ORF36 (Kaposi's sarcoma-associated herpesvirus)/ORF47 (varicella-zoster virus) family, is the sole protein kinase encoded by beta and gamma herpesviruses. The protein kinases phosphorylate both viral and host proteins (16,21,42) and are necessary for efficient virus lytic replication. Consequently, these kinases have been of interest as potential targets for antiviral drug development (37), and the compound 1263W94 (maribavir), which inhibits the cytomegalovirus UL97 protein (3), has been used in phase I clinical trials (27,31,47).EBV infection is prevalent worldwide, and primary infection in adolescence or early adulthood is associated in 30 to 40% of cases with infectious mononucleosis. EBV efficiently infects B cells in the lymphoid tissues of the Waldeyer ring (43). EBV infection of B cells is biased toward establishment of latency with limited viral-gene expression (49). During latent infection, EBV genomes are maintained as extrachromosomal episomes. Replication of episomal genomes utilizes the latency origin of replication, oriP. The only EBV-encoded protein required is the origin binding protein EBNA1. All other essential replication factors are provided by the cell. Expression of the EBV replicative cycle and production of progeny virus take pla...

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Geraniol (GOH), a special type of acyclic monoterpene alcohol, has been widely used to treat many diseases associated with inflammation and apoptosis. Acute lung injury (ALI) is a common clinical disease in humans characterized by pulmonary inflammation and apoptosis. In the present study, we investigated the protective effects of GOH in a mouse model of ALI induced by the intranasal administration of lipopolysaccharide (LPS) and elucidated the underlying molecular mechanisms in RAW 264.7 cells. In vivo, GOH treatment markedly ameliorated pathological injury and pulmonary cell apoptosis and reduced the wet/dry (W/D) weight ratio of lungs, myeloperoxidase (MPO) activity and the production of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). In vitro, the levels of pro-inflammatory cytokines, iNOS and COX-2 were significantly increased in LPS-stimulated RAW 264.7 cells, an effect that was decreased by GOH treatment. Moreover, GOH treatment dramatically reduced the expression of Toll-like receptor 4 (TLR4) and then prevented the nuclear factor-κB (NF-κB) activation. GOH treatment also promoted anti-apoptotic Bcl-2 expression and inhibited pro-apoptotic Bax and Caspase-3 expression. Furthermore, knockdown of TLR4 expression exerted a similar effect and inhibited the phosphorylation of p65, as well as the Bax and Caspase-3 expression. Taken together, these results suggest that GOH treatment alleviates LPS-induced ALI via inhibiting pulmonary inflammation and apoptosis, a finding that might be associated with the inhibition of TLR4-mediated NF-κB and Bcl-2/Bax signalling pathways.

The improved baculovirus vector could mediate prolonged and enhanced foreign gene expression in some mammalian cells. Furthermore, an adequate level of the EBNA-1 protein was essential for the maintenance of the OriP-containing baculovirus genome. The new vector has potential for use in gene therapy.