The dual-specificity phosphatase encoded by vaccinia virus, VH1, is essential for viral transcription in vivo and in vitro. J Virol 1995 Dec;69(12):7823-34
Date
12/01/1995Pubmed ID
7494294Pubmed Central ID
PMC189726DOI
10.1128/JVI.69.12.7823-7834.1995Scopus ID
2-s2.0-0028840684 (requires institutional sign-in at Scopus site) 116 CitationsAbstract
The genetic complexity of vaccinia virus is such that as well as encoding its own transcription and replication machinery, it encodes two protein kinases and a protein phosphatase. The latter enzyme, designated VH1, is a prototype for the dual-specificity class of phosphatases. Here we report that the H1 phosphatase is encapsidated within vaccinia virions and describe the construction of a viral recombinant in which expression of the H1 gene is regulated by the presence or absence of isopropylthiogalactopyranoside (IPTG) in the culture medium. When expression of H1 is repressed, the number of viral particles produced is not compromised but the fraction of these particles which is infectious is significantly reduced. The lack of infectivity of the H1-deficient particles is specifically correlated with their inability to direct the transcription of early genes either in vitro or in vivo. A proximal role for the viral phosphatase in regulating the onset of viral gene expression is implied. Prominent among the encapsidated proteins found to be hyperphosphorylated in H1-deficient virions is the 11-kDa product of the F18 gene; this protein is the major DNA-binding component of the viral nucleoprotein complex. The ability of recombinant H1 phosphatase to reverse this hyperphosphorylation in permeabilized virions strengthens the conclusion that the F18 protein is a bona fide substrate for the H1 phosphatase.
Author List
Liu K, Lemon B, Traktman PMESH terms used to index this publication - Major topics in bold
AllelesAnimals
Base Sequence
DNA Primers
DNA Replication
Dual-Specificity Phosphatases
Gene Expression Regulation, Viral
Isopropyl Thiogalactoside
Kinetics
Mice
Molecular Sequence Data
Phosphorylation
Polymerase Chain Reaction
Promoter Regions, Genetic
Protein Tyrosine Phosphatases
Recombinant Proteins
Restriction Mapping
Species Specificity
Transcription, Genetic
Vaccinia virus
Viral Plaque Assay
Viral Proteins
Virion
Virus Replication
