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Transient expression of the vaccinia virus DNA polymerase is an intrinsic feature of the early phase of infection and is unlinked to DNA replication and late gene expression. J Virol 1992 Jan;66(1):534-47

Date

01/01/1992

Pubmed ID

1727498

Pubmed Central ID

PMC238314

DOI

10.1128/JVI.66.1.534-547.1992

Scopus ID

2-s2.0-0026512768 (requires institutional sign-in at Scopus site)   30 Citations

Abstract

We have studied the expression pattern of the vaccinia virus DNA polymerase during the viral replicative cycle. To monitor polymerase synthesis, a polyclonal antiserum was raised against a TrpE-DNA polymerase fusion protein. Immunoprecipitation and S1 analyses revealed that polymerase synthesis and mRNA levels peak by 2 to 3.5 h postinfection during wild-type infections and then decline, becoming barely detectable by 5 to 6.5 h postinfection. Blocking viral DNA replication by performing infections with temperature-sensitive DNA- mutants at the nonpermissive temperature or by performing wild-type infections in the presence of cytosine beta-D-arabinofuranoside had no effect on polymerase expression. These results indicate that the transient expression of the DNA polymerase is regulated independently of intermediate and late viral gene expression. Cycloheximide, which inhibits protein synthesis and prevents secondary uncoating, caused prolonged and elevated levels of polymerase transcription. Early viral proteins and uncoating, rather than exhaustion of the encapsidated transcription machinery, are presumed to mediate the cessation of polymerase transcription. In the presence of aphidicolin, the polymerase transcripts were maintained at maximal levels rather than exhibiting their normal decline. This inhibition of RNA decay was seen even in infections performed with isolates encoding aphidicolin-resistant DNA polymerases, suggesting that aphidicolin may interfere directly with the process of RNA degradation. Under these conditions, polymerase synthesis remained transient and was not prolonged, despite the continuing presence of available mRNA. These observations suggest that early mRNAs may experience a loss in translation efficiency as infection progresses.

Author List

McDonald WF, Crozel-Goudot V, Traktman P

Author

Paula Traktman Duncan PhD Emeritus Professor in the Microbiology and Immunology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Antibody Specificity
Base Sequence
Cycloheximide
DNA Replication
DNA, Viral
DNA-Directed DNA Polymerase
Gene Expression Regulation, Viral
Mice
Molecular Sequence Data
Mutation
Promoter Regions, Genetic
Transcription, Genetic
Vaccinia virus
Virus Replication