A betabaculovirus DNA polymerase cannot substitute for the DNA polymerase of the alphabaculovirus Autographa californica nucleopolyhedrovirus

Abstract

DNA polymerase (DNApol) is present in all baculoviruses and plays a crucial role in viral DNA replication. Previously we showed that the DNApol of the alphabaculovirus group II Spodoptera litura nucleopolyhedrovirus (SpltNPV) could partially substitute for the DNApol of a group I alphabaculovirus, Autographa californica multiple nucleopolyhedrovirus (AcMNPV). However, it is not known if a betabaculovirus DNApol could subsititute for the alphabaculovirus DNApol in AcMNPV. In this report, DNApol of the betabaculovirus Pieris rapae granulovirus (PiraGV) was inserted into a dnapol-null AcMNPV bacmid, creating Bac-AcΔpol:PrPol. The repair virus did not spread to neighboring cells; virus growth curve and real-time PCR revealed that the PiraGV dnapol substitution abrogated AcMNPV DNA replication and virus production. Immunofluorescence microscopy showed that PiraGV DNApol could be expressed and localized to the nucleus. Collectively, our results suggested that the alphabaculovirus AcMNPV DNApol could not be replaced by a DNApol from the betabaculovirus, PiraGV.

Mechanisms Mediating Nuclear Trafficking Involved in Viral Propagation by DNA Viruses

“…These similarities originate from the requirement for viral replication complexes and a specialized nuclear compartment. A key component of viral replication complexes is DNA-dependent DNA polymerase, and most DNA viruses, such as baculoviruses, HBV and herpesviruses, exploit virally self-encoded DNA polymerase to proceed with the synthesis of viral DNA [57,62,63,64,65,66]. As a crucial enzyme in viral replication, DNA polymerase is also the main target for antiviral therapeutics.…”