Expression of Glycoproteins in Wild-Type and Vaccine Strains of Varicella Zoster Virus
Abstract
Characterization of varicella zoster virus (VZV) glycoprotein transcripts, polypeptides, and biologic properties is of major importance in understanding the growthcycle and pathogenesis of VZV. We have now characterized in detail those transcripts mapping to VZV glycoprotein IV (gpIV) and glycoprotein V (gpV). Northern blot, SI nuclease and primer extension analyses, indicate that a major 1.55Kb transcript mapped to the gpIV open reading frame (ORF) and 1.95Kb and 2.5Kb transcripts mapped to the gpV ORF in a wild-type lab strain Scott. Likely TATA and CAT box motifs were located near the 5' termini and polyadenylation signals near the 3' termini of all these transcripts. Previously in our laboratory we observed that the live attenuated varicella vaccine strain, Oka, contained a 168bp deletion in the R2 repeat region found in the gpV ORF. The gpV transcripts in strain Oka were both smaller, 2.3Kb and 1.8Kb in size than Scott, as well as >20-feld less in abundance. To test the mechanism for the deficient gpV transcription in Oka, we tested the R2 repeats from both Scott and Oka for enhancer activity but none was detected. Subsequently, the Scott and Oka promoters were tested for promoter activity in transient expression assays using gpV promoter/reporter gene fusions. The gpV promoters required viral transactivation with VZV, however, both Scott and Oka strains activated the gpV promoters similarly. The gpIV promoter was also studied in a similar manner described for gpV and was also shown to require VZV transactivation for activity. Additionally, it was shown that two VZV proteins ORF4 and ORF62 could stimulate the gpIV promoter. The gpV polypeptide products were 95-105 kDa in size for strain Scott and displayed a patchy surface fluorescence in VZV-infected cells. Oka gpV polypeptides were slightly smaller in size, and accumulated to only 2% of the Scott gpV levels, correlating to the transcript levels. The gpV polypeptides were also glycosylated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 18, 1990
- Accession Number
- AD1010967
Entities
People
- Paul D. Ling
Organizations
- Uniformed Services University of the Health Sciences