The varicella–zoster virus–mediated delayed host shutoff: open reading frame 17 has no major function, whereas immediate–early 63 protein represses heterologous gene expression

2005 ◽  
Vol 7 (15) ◽  
pp. 1519-1529 ◽  
Author(s):  
Nathalie Desloges ◽  
Markus Rahaus ◽  
Manfred H. Wolff
Keyword(s):  
Gene Expression ◽  
Varicella Zoster Virus ◽  
Heterologous Gene Expression ◽  
Open Reading Frame ◽  
Heterologous Gene ◽  
Immediate Early ◽  
Reading Frame ◽  
Varicella Zoster ◽  
Major Function ◽  
Host Shutoff

scholarly journals The Immediate-Early Gene Product Encoded by Open Reading Frame 57 of Herpesvirus Saimiri Modulates Gene Expression at a Posttranscriptional Level

1998 ◽  
Vol 72 (1) ◽  
pp. 857-861 ◽  
Author(s):  
Adrian Whitehouse ◽  
Matthew Cooper ◽  
David M. Meredith
Keyword(s):  
Gene Expression ◽  
Gene Product ◽  
Target Gene ◽  
Immediate Early Gene ◽  
Open Reading Frame ◽  
Early Gene ◽  
Immediate Early ◽  
Herpesvirus Saimiri ◽  
Amino Acid Homology ◽  
Reading Frame

ABSTRACT The herpesvirus saimiri (HVS) immediate-early gene product encoded by open reading frame (ORF) 57 shares limited amino acid homology with HSV-1 ICP27 and Epstein-Barr virus BMLF1, both regulatory proteins. The ORF 57 gene has been proposed to be spliced based on the genome sequence, and here we confirm the intron-exon structure of the gene. We also demonstrate that a cDNA construct of the ORF 57 gene product represses the transactivating capability of the ORF 50a gene product (which is produced from a spliced transcript), but activates that of ORF 50b (an unspliced transcript). Further analyses with cotransfection experiments show that ORF 57 can either activate or repress expression from a range of both early and late HVS promoters, depending on the target gene. These results indicate that repression of gene expression mediated by the ORF 57 gene product is dependent on the presence of an intron within the target gene encoding region. Furthermore, Northern blot analysis demonstrates that the levels of mRNA transcribed from genes not containing an intron are not significantly affected in the presence of the ORF 57 gene product. This suggests that it regulates gene expression through a posttranscriptional mechanism.

Varicella-Zoster Virus (VZV) Virion-Associated Transactivator Open Reading Frame 62 Protein Enhances the Infectivity of VZV DNA

Virology ◽  
1994 ◽  
Vol 200 (1) ◽  
pp. 297-300 ◽  
Author(s):  
Masako Moriuchi ◽  
Hiroyuki Moriuchi ◽  
Stephen E. Straus ◽  
Jeffrey I. Cohen
Keyword(s):  
Varicella Zoster Virus ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Varicella Zoster

scholarly journals Neither LAT nor Open Reading Frame P Mutations Increase Expression of Spliced or Intron-Containing ICP0 Transcripts in Mouse Ganglia Latently Infected with Herpes Simplex Virus

2002 ◽  
Vol 76 (10) ◽  
pp. 4764-4772 ◽  
Author(s):  
Shun-Hua Chen ◽  
Lily Yeh Lee ◽  
David A. Garber ◽  
Priscilla A. Schaffer ◽  
David M. Knipe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Open Reading Frame ◽  
Early Gene ◽  
Immediate Early ◽  
Gene Encoding ◽  
Reading Frame ◽  
Latently Infected ◽  
Simplex Virus

ABSTRACT Latent infections by herpes simplex virus are characterized by repression of productive-cycle gene expression. Several hypotheses to explain this repression involve inhibition of expression of the immediate-early gene activator ICP0 during latency. To address these hypotheses, we developed quantitative reverse transcriptase-PCR assays that detected spliced and intron-containing ICP0 transcripts in mouse ganglia latently infected with wild-type virus. In these ganglia, the numbers of spliced ICP0 transcripts correlated better with the numbers of transcripts from the immediate-early gene encoding ICP4 than with those from the early gene encoding thymidine kinase. There were fewer spliced than intron-containing ICP0 transcripts on average, with considerable ganglion-to-ganglion variation. We then investigated whether ICP0 expression in latently infected ganglia is reduced by the latency-associated transcripts (LATs) and whether splicing of ICP0 transcripts is inhibited by the product of open reading frame (ORF) P. A LAT deletion mutation which essentially eliminates expression of the major LATs did not appreciably increase levels of ICP0 transcripts. LAT deletion mutants did, however, appear to express reduced levels of intron-containing ICP0 transcripts. ORF P mutations did not alter levels of ICP0 transcripts in a manner consistent with inhibition of ICP0 splicing by ORF P. Although these results argue against antisense inhibition of ICP0 expression by LATs or inhibition of ICP0 splicing by ORF P, they are consistent with the possibilities of a block between immediate-early and early gene expression and regulation of spliced versus intron-containing ICP0 transcripts in latently infected ganglia.

scholarly journals Nuclear Accumulation of IE62, the Varicella-Zoster Virus (VZV) Major Transcriptional Regulatory Protein, Is Inhibited by Phosphorylation Mediated by the VZV Open Reading Frame 66 Protein Kinase

2000 ◽  
Vol 74 (5) ◽  
pp. 2265-2277 ◽  
Author(s):  
Paul R. Kinchington ◽  
Karen Fite ◽  
Stephanie E. Turse
Keyword(s):  
Protein Kinase ◽  
Varicella Zoster Virus ◽  
Nuclear Localization ◽  
Kinase Activity ◽  
Open Reading Frame ◽  
Nuclear Accumulation ◽  
Protein Kinase Activity ◽  
Reading Frame ◽  
Varicella Zoster ◽  
In Cells

ABSTRACT IE62, the major transcriptional activator protein encoded by varicella-zoster virus (VZV), locates to the nucleus when expressed in transfected cells. We show here that cytoplasmic forms of IE62 accumulate in transfected and VZV-infected cells as the result of the protein kinase activity associated with VZV open reading frame 66 (ORF66). Expression of the ORF66 protein kinase but not the VZV ORF47 protein kinase impaired the ability of coexpressed IE62 to transactivate promoter-reporter constructs. IE62 that was coexpressed with the ORF66 protein accumulated predominantly in the cytoplasm, whereas the normal nuclear localization of other proteins was not affected by the ORF66 protein. In cells infected with VZV, IE62 accumulated in the cytoplasm at late times of infection, whereas in cells infected with a VZV recombinant unable to express ORF66 protein (ROka66S), IE62 was completely nuclear. Point mutations introduced into the predicted serine/threonine catalytic domain and ATP binding domain of ORF66 abrogated its ability to influence IE62 nuclear localization, indicating that the protein kinase activity was required. The region of IE62 that was targeted by ORF66 was mapped to amino acids 602 to 733. IE62 peptides containing this region were specifically phosphorylated in cells coexpressing the ORF66 protein kinase and in cells infected with wild-type VZV but were not phosphorylated in cells infected with ROka66S. We conclude that the ORF66 protein kinase phosphorylates IE62 to induce its cytoplasmic accumulation, most likely by inhibiting IE62 nuclear import.

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