Analysis of Kinase Effects on Viral Replication of the Papillomavirus
Papillomaviruses are a genera of small tumor viruses in the Papovaviridae family, whose lifecycle and replication ability is directed by epithelial differentiation. During latency, papillomavirus DNA replication occurs synchronously with the host cell's replication by the activation of the El protein. To elucidate the effects upon viral replication, this study utilized chemical inhibition of several kinases predicted to phosphorylate, and subsequently modify the activity of, the papilloma virus' E 1 protein. The amount of DNA replicated was observed via autoradiography following DNA extraction and southern blotting of BPV-transformed C127 cells. Sample extracts from cells exposed to specific chemical inhibitors of PKC, CDK, and DNAPK showed a consistent and significant decrease in viral DNA when compared to the DNA abundance of a control set of extracts. Extracts of cells subjected to inhibition of CK2 displayed an observable increase in replicated viral DNA. To ensure that the kinase modification was not effecting the growth or viability of the cells, a neutral red assay was performed and found no significant difference between control and chemically treated samples in cell viability or overall cell number. These findings, in conjunction with the differential viral DNA abundance, implicate that kinases PKC, CDK, CK2, and DNAPK, have a role in viral genome replication.