DNA polymerase in pseudorabies virus infected cells

Area of Science:

• Virology
• Molecular Biology
• Biochemistry

Background:

• BHK 21/C13 cells are commonly used for viral studies.
• DNA polymerase is crucial for viral replication.
• Herpesviruses, including pseudorabies virus (PRV) and herpes simplex viruses (HSV-1, HSV-2), encode their own DNA polymerases.

Purpose of the Study:

• To investigate the origin of DNA polymerase activity in PRV-infected cells.
• To determine if the viral DNA polymerase is specified by the PRV genome.
• To differentiate the PRV-induced DNA polymerase from host cell and other herpesvirus polymerases.

Main Methods:

• Infection of BHK 21/C13 cells with pseudorabies virus.
• Assay of DNA polymerase activity in infected cell extracts.
• Incubation with specific antisera (anti-PRV, pre-immune, anti-HSV-1, anti-HSV-2).
• In vitro DNA polymerase assay with varying KCl concentrations.

Main Results:

• DNA polymerase activity in PRV-infected cells was inhibited by antiserum to PRV.
• Activity was not inhibited by pre-immune serum or antisera to HSV-1 or HSV-2.
• The PRV-induced enzyme exhibited a distinct KCl requirement compared to cellular or HSV enzymes.

Conclusions:

• The DNA polymerase activity observed in PRV-infected cells is likely specified by the pseudorabies virus itself.
• The PRV DNA polymerase is antigenically distinct from HSV-1 and HSV-2 DNA polymerases.
• The enzyme possesses unique biochemical properties, such as KCl dependency, differentiating it from other viral and cellular DNA polymerases.