Isolation and characterization of a functional cDNA encoding ICP0 from herpes simplex virus type 1.
The IE-0 gene of herpes simplex virus type 1 (HSV-1) contains two introns and encodes ICP0, a powerful transcriptional activator. We have isolated a cDNA clone that encodes ICP0 from a lambda gt10 cDNA library constructed from RNAs made from HSV-1-infected HeLa cells. DNA sequence analysis of this clone confirmed the predicted intron/exon boundaries (L. J. Perry, F. J. Rixon, R. D. Everett, M. C. Frame, and D. J. McGeoch, J. Gen. Virol. 67:2365-2380, 1986). Following transfection, a plasmid containing the cDNA copy of IE-0 directed the synthesis of ICP0, which was appropriately compartmentalized and distributed in the nucleus, as revealed by immunofluorescence. A transient expression assay was used to demonstrate that this cDNA copy retained the ability to transactivate the HSV-1 promoters for the IE-0 gene (an immediate-early gene), the thymidine kinase gene (an early gene), and the glycoprotein C gene (a late gene). The product of this cDNA clone cooperated with ICP4 to activate expression from the thymidine kinase gene promoter in a synergistic manner. The availability of a functional cDNA copy encoding ICP0 provides the opportunity to express this protein in vector systems that do not recognize eucaryotic donor and acceptor splicing signals to overexpress ICP0.
Zhu
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Department of Microbiology, Columbia University, New York, New York 10032.
Chen
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JX
Silverstein
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D001483:Base Sequence; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics* / Q000302:isolation & purification; D005814:Genes, Viral; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins; D007438:Introns; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D018139:Simplexvirus / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics*; D044767:Ubiquitin-Protein Ligases; D014764:Viral Proteins / Q000096:biosynthesis / Q000235:genetics*; D015678:Viral Structural Proteins / Q000235:genetics
D004279:DNA, Viral; D017874:Immediate-Early Proteins; D015534:Trans-Activators; D014764:Viral Proteins; D015678:Viral Structural Proteins; D044767:Ubiquitin-Protein Ligases; C051804:Vmw110 protein, Human herpesvirus 1