Roscovitine, a Specific Inhibitor of Cellular Cyclin-Dependent Kinases, Inhibits Herpes Simplex Virus DNA Synthesis in the Presence of Viral Early Proteins

Abstract

We have previously shown that two inhibitors specific for cellular cyclin-dependent kinases (cdks), Roscovitine (Rosco) and Olomoucine (Olo), block the replication of herpes simplex virus (HSV). Based on these results, we demonstrated that HSV replication requires cellular cdks that are sensitive to these drugs (L. M. Schang, J. Phillips, and P. A. Schaffer. J. Virol. 72:5626-5637, 1998). We further established that at least two distinct steps in the viral replication cycle require cdks: transcription of immediate-early (IE) genes and transcription of early (E) genes (L. M. Schang, A. Rosenberg, and P. A. Schaffer, J. Virol. 73:2161-2172, 1999). Since Rosco inhibits HSV replication efficiently even when added to infected cells at 6 h postinfection, we postulated that cdks may also be required for viral functions that occur after E gene expression. In the study presented herein, we tested this hypothesis directly by measuring the efficiency of viral replication, viral DNA synthesis, and expression of several viral genes during infections in which Rosco was added after E proteins had already been synthesized. Rosco inhibited HSV replication, and specifically viral DNA synthesis, when the drug was added at the time of release from a 12-h phosphonoacetic acid (PAA)-induced block in viral DNA synthesis. Inhibition of DNA synthesis was not a consequence of inhibition of expression of IE or E genes in that Rosco had no effect on steady-state levels of two E transcripts under the same conditions in which it inhibited viral DNA synthesis. Moreover, viral DNA synthesis was inhibited by Rosco even in the absence of protein synthesis. In a second series of experiments, the replication of four HSV mutants harboring temperature-sensitive mutations in genes essential for viral DNA replication was inhibited when Rosco was added at the time of shift-down from the nonpermissive to the permissive temperature. Viral DNA synthesis was inhibited by Rosco under these conditions, whereas expression of viral E genes was not affected. We conclude that cellular Rosco-sensitive cdks are required for replication of viral DNA in the presence of viral E proteins. This requirement may indicate that HSV DNA synthesis is functionally linked to transcription, which requires cdks, or that both viral transcription and DNA replication, independently, require viral or cellular factors activated by Rosco-sensitive cdks.Herpes simplex virus (HSV) replicates in both cycling and noncycling cells, including terminally differentiated neurons. HSV replication, however, requires cellular functions associated with cell cycle progression. Thus, HSV replicates more efficiently in actively dividing than growth-arrested cells. This difference in replication efficiency is especially prominent among viral mutants which lack specific viral functions such as those provided by the regulatory proteins ICP0 and VP16 or by enzymes involved in nucleotide metabolism, such as thymidine kinase (TK) or ribonucleotide reductase (9, 16, 25). The dependence on cell cycle-activat...

Supramolecular Structures and Tautomerism of Carboxylate Salts of Adenine and Pharmaceutically Relevant N6-Substituted Adenine

“…61 A building block found in all three supramolecular structures is the R2 2 (9) heterosynthon based on double H bonds between a protonated Hoogsteen site and a carboxylate group. Besides the R2 2 (9) heterosynthon, 1 contains an R2 2 (8) …”

“…1-3 N 6 -furfurylaminopurine (kinetin) is a representative of naturally occurring adenine-type cytokinins, a class of plant growth factors that can also act as inhibitors of certain human protein kinases. 4,5 Some kinetin analogues such as olomoucine 6,7 and roscovitine 8 selectively inhibit cyclindependent kinases, which play an essential role in the regulation of the cell division cycle, 6,9 and therefore are potent anticancer agents. Roscovitine, for example, has entered clinical trials for the treatment of non-small cell lung cancer and leukemia.…”

An inhibitor of cyclin-dependent kinases suppresses TLR signaling and increases the susceptibility of cancer patients to herpes viridae

“…These observations could appear paradoxical in as much as recent studies have shown that replication of Herpes Simplex Virus (and other large DNA viruses) requires cellular proteins including CDKs. [14][15][16][17][18][19][20][21] One of the potential mechanisms accounting for these adverse effects might be the negative regulation of TLR signaling pathways by CDKi and/or GSK3β inhibition, as suggested by previous in vitro studies.…”

“…Tumor associated-mutations deregulate distinct CDKcyclin complexes causing unscheduled proliferation. Deregulation of CDK4 and CDK6 activities have been implicated in a variety of human malignancies, CDK4 being hyperactive in epithelial a 4-week cycle, i.e., with treatment on days 1, 8, 15 followed by a 2-week resting period (day [16][17][18][19][20][21][22][23][24][25][26][27][28] (Fig. 1A).…”

Roscovitine inhibits thyroid hormone‐induced tail regression of the frog tadpole and reveals a role for cyclin C/Cdk8 in the establishment of the metamorphic gene expression program

“…In human cell lines examined, roscovitine arrests cells in the G 1 and the G 2 /M phases of the cell cycle Pippin et al, 1997;Alessi et al, 1998), inhibits DNA synthesis (Yakisich et al, 1999;Schang et al, 2000), causes nucleolar fragmentation (David-Pfeuty, 1999), induces apoptosis (Mgbonyebi et al, 1999;Atienza et al, 2000), and inhibits apoptosis (Maas et al, 1998;Choi et al, 1999;Hiromura et al, 1999;Padmanabhan et al, 1999;Giardina and Beart, 2002).…”