The Product of Varicella-zoster Virus Gene 62 Autoregulates Its Own Promoter

Disney, Graham H.; Mckee, Thomas Alexander; Preston, Chris M.; Everett, Roger D.

doi:10.1099/0022-1317-71-12-2999

Cited by 45 publications

(39 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ORF62 and ORF63 are transcribed in opposite directions, and this region is presumed to contain promoter sequences for both genes. The IE62 promoter has three TAAT GARAT motifs and other sites that are known to bind cellular and viral protein complexes, which were preserved in the inserted sequence (11,31,41,42). We cannot exclude the possibility that reduced early IE62 protein synthesis was due to absence of promoter elements located farther upstream within the ORF63 coding sequence.…”

Section: Discussionmentioning

confidence: 99%

Mutational Analysis of Open Reading Frames 62 and 71, Encoding the Varicella-Zoster Virus Immediate-Early Transactivating Protein, IE62, and Effects on Replication In Vitro and in Skin Xenografts in the SCID-hu Mouse In Vivo

Sato

Ito

Hinchliffe

et al. 2003

J Virol

View full text Add to dashboard Cite

The varicella-zoster virus (VZV) genome has unique long (U L ) and unique short (U S ) segments which are flanked by internal repeat (IR) and terminal repeat (TR) sequences. The immediate-early 62 (IE62) protein, encoded by open reading frame 62 (ORF62) and ORF71 in these repeats, is the major VZV transactivating protein. Mutational analyses were done with VZV cosmids generated from parent Oka (pOka), a low-passage clinical isolate, and repair experiments were done with ORF62 from pOka and vaccine Oka (vOka), which is derived from pOka. Transfections using VZV cosmids from which ORF62, ORF71, or the ORF62/71 gene pair was deleted showed that VZV replication required at least one copy of ORF62. The insertion of ORF62 from pOka or vOka into a nonnative site in U S allowed VZV replication in cell culture in vitro, although the plaque size and yields of infectious virus were decreased. Targeted mutations in binding sites reported to affect interaction with IE4 protein and a putative ORF9 protein binding site were not lethal. Single deletions of ORF62 or ORF71 from cosmids permitted recovery of infectious virus, but recombination events repaired the defective repeat region in some progeny viruses, as verified by PCR and Southern hybridization. VZV infectivity in skin xenografts in the SCID-hu model required ORF62 expression; mixtures of single-copy recombinant Oka⌬62 (rOka⌬62) or rOka⌬71 and repaired rOka generated by recombination of the single-copy deletion mutants were detected in some skin implants. Although insertion of ORF62 into the nonnative site permitted replication in cell culture, ORF62 expression from its native site was necessary for cell-cell spread in differentiated human skin tissues in vivo.Varicella-zoster virus (VZV) belongs to the alphaherpesvirus subfamily of the Herpesviridae. VZV is the causative agent of varicella, which is characterized by cell-associated viremia and a cutaneous vesicular rash (4). VZV establishes latency in cells within sensory ganglia during primary infection. VZV reactivation from latency results in herpes zoster, a localized skin rash in the distribution of nerves from the affected ganglion. VZV is the first human herpesvirus for which a vaccine has been developed to prevent primary infection (58). This live attenuated varicella vaccine was created by serial passage of a wild-type clinical isolate, the parent Oka (pOka) strain, in guinea pig embryo cells and human fibroblasts to generate the varicella vaccine virus (vOka).The VZV genome consists of approximately 125 kb and has at least 70 unique open reading frames (ORFs) (52). As is characteristic of herpesviruses, the double-stranded DNA genome has unique long (U L ) and unique short (U S ) segments which are flanked by internal repeat (IR) and terminal repeat (TR) sequences. Three duplicated genes, ORF62/71, ORF63/ 70, and ORF64/69, are located in repeats at each end of the U S segment. The two VZV origins of replication, designated OriS, are also located in these repeat regions. The immediate-early 62 (IE62) protein,...

show abstract

Section: Discussionmentioning

confidence: 99%

Mutational Analysis of Open Reading Frames 62 and 71, Encoding the Varicella-Zoster Virus Immediate-Early Transactivating Protein, IE62, and Effects on Replication In Vitro and in Skin Xenografts in the SCID-hu Mouse In Vivo

Sato

Ito

Hinchliffe

et al. 2003

J Virol

View full text Add to dashboard Cite

show abstract

“…High levels of IE62 are associated with viral tegument (24) and a recombinant HSV-1 with both copies of ICP4 replaced by VZV IE62 has been constructed (11). IE62 can transactivate all three putative kinetic classes of VZV gene promoters-i.e., the IE, early, and late gene promoters (5,10,15,16,22,38,47,52)-and can transrepress its own promoter (5,12,49). Production of infectious VZV generated by the transfection of purified viral DNA is strongly increased by the addition of an IE62-expressing plasmid, and it has been hypothesized that virion-associated IE62 may play a crucial role in stimulating the IE events upon infection (44).…”

mentioning

confidence: 99%

Comparison of the Complete DNA Sequences of the Oka Varicella Vaccine and Its Parental Virus

Gomi

Sunamachi

Mori

et al. 2002

J Virol

173

179

View full text Add to dashboard Cite

The DNA sequences of the Oka varicella vaccine virus (V-Oka) and its parental virus (P-Oka) were completed. Comparison of the sequences revealed 42 base substitutions, which led to 20 amino acid conversions and length differences in tandem repeat regions (R1, R3, and R4) and in an origin of DNA replication. Amino acid substitutions existed in open reading frames (ORFs) 6, 9A, 10, 21, 31, 39, 50, 52, 55, 59, 62, and 64. Of these, 15 base substitutions, leading to eight amino acid substitutions, were in the gene 62 region alone. Further DNA sequence analysis showed that these substitutions were specific for V-Oka and were not present in nine clinical isolates. The immediate-early gene 62 product (IE62) of P-Oka had stronger transactivational activity than the mutant IE62 contained in V-Oka in 293 and CV-1 cells. An infectious center assay of a plaque-purified clone (S7-01) from the V-Oka with 8 amino acid substitutions in ORF 62 showed smaller plaque formation and less-efficient virus-spreading activity than did P-Oka in human embryonic lung cells. Another clone (S-13) with only five substitutions in ORF 62 spread slightly faster than S7-01 but not as effectively as P-Oka. Moreover, transient luciferase assay in 293 cells showed that transactivational activities of IE62s of S7-01 and S7-13 were lower than that of P-Oka. Based on these results, it appears that amino acid substitutions in ORF 62 are responsible for virus growth and spreading from infected to uninfected cells. Furthermore, the Oka vaccine virus was completely distinguishable from P-Oka and 54 clinical isolates by seven restriction-enzyme fragment length polymorphisms that detected differences in the DNA sequence.Varicella-zoster virus (VZV) is a human herpesvirus that causes chickenpox (varicella) and shingles (herpes zoster). A live attenuated varicella vaccine, the Oka strain was originally developed by Takahashi et al. in Japan (56) and is routinely used in children in Japan and other countries, including the United States. Clinical symptoms caused by this live vaccine are very rare in healthy children. Although the Oka vaccine virus (V-Oka) is an avirulent virus, its parental virus (P-Oka), isolated from a patient with typical varicella, is thought to be virulent in vivo. It has not been clarified which gene(s) is involved in the pathogenicity of VZV infection. Thus, comparison of the complete genomes of V-Oka and P-Oka should reveal correlations between DNA sequence and virulence.The complete DNA sequence of the VZV Dumas strain was first determined by Davison and Scott (9). The genome is a linear double-stranded DNA of ca. 125,000 bp and consists of unique long regions (ULs) flanked by terminal repeat long (TRL) and internal repeat long (IRL) inverted repeat regions, and a unique short (US) region flanked by internal repeat short (IRS) and terminal repeat short (TRS) inverted repeat regions. The genome contains ca. 70 open reading frames (ORFs), three of which exist in both IRS and TRS regions; genes 62 through 64 correspond to genes 69 throug...

show abstract

“…Transfections were carried out using LipofectAMINE Plus (Life Technologies, Inc.) according to the manufacturer's protocols. Reporter plasmids pIE3-CAT, containing the HSV-1 ICP4 promoter (gift from Dr. R. D. Everett), and 2xNF-B-LUC (gift from Dr. M. Karin), and IB␣ super-repressor (IB␣-AA) expression vector have been described (4,19). After transfection, cells were maintained in RPMI 1640 containing 10% fetal calf serum for 24 h before infection with HSV-1.…”

Section: Methodsmentioning

confidence: 99%

Activation of IκB Kinase by Herpes Simplex Virus Type 1

Amici¹,

Belardo²,

Rossi³

et al. 2001

Journal of Biological Chemistry

123

View full text Add to dashboard Cite

Herpes simplex viruses (HSV) are ubiquitous pathogens causing a variety of diseases ranging from mild illness to severe life-threatening infections. HSV utilize cellular signaling pathways and transcription factors to promote their replication. Here we report that HSV type 1 (HSV-1) induces persistent activation of transcription factor NF-B, a critical regulator of genes involved in inflammation, by activating the IB kinase (IKK) in the early phase of infection. Activated NF-B enhances HSV-1 gene expression. HSV-1-induced NF-B activation is dependent on viral early protein synthesis and is not blocked by the anti-herpetic drug acyclovir. IKK inhibition by the anti-inflammatory cyclopentenone prostaglandin A 1 blocks HSV-1 gene expression and reduces virus yield by more than 3000-fold. The results identify IKK as a potential target for anti-herpetic drugs and suggest that cyclopentenone prostaglandins or their derivatives could be used in the treatment of HSV infection.One intriguing aspect of herpesviruses is their ability to influence host defense mechanisms and replication of other pathogens by inducing a stress response, via activation of cellular transcription factors, among which is nuclear factor-B (NF-B).1 NF-B is a critical regulator of the immediate-early pathogen response, playing an important role in promoting inflammation and viral gene expression (1). In most eukaryotic cells NF-B exists as an inactive cytoplasmic complex, whose predominant form is a heterodimer composed of p50 and p65 (Rel A) subunits, bound to inhibitory proteins of the IB family, usually IB␣ (1, 2). NF-B is activated in response to a variety of stress and pathogenic stimuli, including UV radiation, bacterial and viral infection, and proinflammatory cytokines (2, 3). Several stimuli activate NF-B by augmenting the activity of the IB kinase (IKK) complex, containing two catalytic subunits (IKK-␣ and IKK-␤) and the IKK-␥ or NEMO regulatory subunit (4, 5). IKK phosphorylates IBs at sites that trigger their ubiquitination and proteasome-mediated degradation (1, 4). Freed NF-B dimers translocate to the nucleus and activate a variety of genes encoding adhesion molecules, inflammatory and chemotactic cytokines, cytokine receptors, and enzymes that produce inflammatory mediators (1, 2). NF-B also activates the transcription of viral genes and is involved in several pathological events including progression of AIDS by enhancing human immunodeficiency virus type 1 (HIV-1) transcription (6, 7). Several viruses, including HIV-1 (8), cytomegalovirus (9), SV40 (10), and hepatitis B virus (11), contain functionally important NF-B-binding sites. In the case of HSV-1, NF-B-binding sites are located in the ICP0 and Vmw65 genes (12).In addition to containing NF-B-binding sites in its genome, HSV-1 can also induce NF-B nuclear translocation (13), and two immediate-early (IE) proteins, ICP4 and ICP27, were found to be required for this effect (13, 14); however, the signaling pathway utilized by the virus to activate the factor has still not been defin...

show abstract

The Product of Varicella-zoster Virus Gene 62 Autoregulates Its Own Promoter

Cited by 45 publications

References 25 publications

Mutational Analysis of Open Reading Frames 62 and 71, Encoding the Varicella-Zoster Virus Immediate-Early Transactivating Protein, IE62, and Effects on Replication In Vitro and in Skin Xenografts in the SCID-hu Mouse In Vivo

Mutational Analysis of Open Reading Frames 62 and 71, Encoding the Varicella-Zoster Virus Immediate-Early Transactivating Protein, IE62, and Effects on Replication In Vitro and in Skin Xenografts in the SCID-hu Mouse In Vivo

Comparison of the Complete DNA Sequences of the Oka Varicella Vaccine and Its Parental Virus

Activation of IκB Kinase by Herpes Simplex Virus Type 1

Contact Info

Product

Resources

About