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Winship Herr - One of the best experts on this subject based on the ideXlab platform.
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Proteolytic processing is necessary to separate and ensure proper cell growth and cytokinesis functions of HCF-1
The EMBO journal, 2003Co-Authors: Eric Julien, Winship HerrAbstract:HCF-1 is a highly conserved and abundant chromatin-associated host cell factor required for transcriptional activation of herpes simplex virus immediate-early genes by the virion Protein VP16. HCF-1 exists as a heterodimeric complex of associated N- (HCF-1N) and C- (HCF-1C) terminal subunits that result from proteolytic processing of a precursor Protein. We have used small-interfering RNA (siRNA) to inactivate HCF-1 in an array of normal and transformed mammalian cells to identify its cellular functions. Our results show that HCF-1 is a broadly acting regulator of two stages of the cell cycle: exit from mitosis, where it ensures proper cytokinesis, and passage through the G1 phase, where it promotes cell cycle progression. Proteolytic processing is necessary to separate and ensure these two HCF-1 activities, which are performed by separate HCF-1 subunits: the HCF-1N subunit promotes passage through the G1 phase whereas the HCF-1C subunit is involved in proper exit from mitosis. These results suggest that HCF-1 links the regulation of exit from mitosis and the G1 phase of cell growth, possibly to coordinate the reactivation of gene expression after mitosis.
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Stabilization but not the transcriptional activity of herpes simplex virus VP16-induced complexes is evolutionarily conserved among HCF family members.
Journal of virology, 2001Co-Authors: Soyoung Lee, Winship HerrAbstract:The human herpes simplex virus (HSV) Protein VP16 induces formation of a transcriptional regulatory complex with two cellular factors-the POU homeodomain transcription factor Oct-1 and the cell proliferation factor HCF-1-to activate viral immediate-early-gene transcription. Although the cellular role of Oct-1 in transcription is relatively well understood, the cellular role of HCF-1 in cell proliferation is enigmatic. HCF-1 and the related Protein HCF-2 form an HCF Protein family in humans that is related to a Caenorhabditis elegans homolog called CeHCF. In this study, we show that all three Proteins can promote VP16-induced-complex formation, indicating that VP16 targets a highly conserved function of HCF Proteins. The resulting VP16-induced complexes, however, display different transcriptional activities. In contrast to HCF-1 and CeHCF, HCF-2 fails to support VP16 activation of transcription effectively. These results suggest that, along with HCF-1, HCF-2 could have a role, albeit probably a different role, in HSV infection. CeHCF can mimic HCF-1 for both association with viral and cellular Proteins and transcriptional activation, suggesting that the function(s) of HCF-1 targeted by VP16 has been highly conserved throughout metazoan evolution.
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Loss of HCF-1-chromatin association precedes temperature-induced growth arrest of tsBN67 cells.
Molecular and cellular biology, 2001Co-Authors: Joanna Wysocka, Patrick T. Reilly, Winship HerrAbstract:Human HCF-1 is a large, highly conserved, and abundant nuclear Protein that plays an important but unknown role in cell proliferation. It also plays a role in activation of herpes simplex virus immediate-early gene transcription by the viral regulatory Protein VP16. A single proline-to-serine substitution in the HCF-1 VP16 interaction domain causes a temperature-induced arrest of cell proliferation in hamster tsBN67 cells and prevents transcriptional activation by VP16. We show here that HCF-1 is naturally bound to chromatin in uninfected cells through its VP16 interaction domain. HCF-1 is chromatin bound in tsBN67 cells at permissive temperature but dissociates from chromatin before tsBN67 cells stop proliferating at the nonpermissive temperature, suggesting that loss of HCF-1 chromatin association is the primary cause of the temperature-induced tsBN67 cell proliferation arrest. We propose that the role of HCF-1 in cell proliferation is to regulate gene transcription by associating with a multiplicity of DNA-bound transcription factors through its VP16 interaction domain.
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HCF-1 Amino- and Carboxy-Terminal Subunit Association through Two Separate Sets of Interaction Modules: Involvement of Fibronectin Type 3 Repeats
Molecular and cellular biology, 2000Co-Authors: Angus C. Wilson, Michael Boutros, Kristina M. Johnson, Winship HerrAbstract:When herpes simplex virus infects permissive cells, the viral regulatory Protein VP16 forms a specific complex with HCF-1, a preexisting nuclear Protein involved in cell proliferation. The majority of HCF-1 in the cell is a complex of associated amino (HCF-1N)- and carboxy (HCF-1C)-terminal subunits that result from an unusual proteolytic processing of a large precursor polypeptide. Here, we have characterized the structure and function of sequences required for HCF-1N and HCF-1C subunit association. HCF-1 contains two matched pairs of self-association sequences called SAS1 and SAS2. One of these matched association sequences, SAS1, consists of a short 43-amino-acid region of the HCF-1N subunit, which associates with a carboxy-terminal region of the HCF-1C subunit that is composed of a tandem pair of fibronectin type 3 repeats, a structural motif known to promote Protein-Protein interactions. Unexpectedly, the related Protein HCF-2, which is not proteolyzed, also contains a functional SAS1 association element, suggesting that this element does not function solely to maintain HCF-1N and HCF-1C subunit association. HCF-1N subunits do not possess a nuclear localization signal. We show that, owing to a carboxy-terminal HCF-1 nuclear localization signal, HCF-1C subunits can recruit HCF-1N subunits to the nucleus.
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Crystal structure of the conserved core of the herpes simplex virus transcriptional regulatory Protein VP16.
Genes & development, 1999Co-Authors: Yu Liu, Weimin Gong, C. Chris Huang, Winship Herr, Xiaodong ChengAbstract:On infection, the herpes simplex virus (HSV) virion Protein VP16 (Vmw65; alphaTIF) forms a transcriptional regulatory complex-the VP16-induced complex-with two cellular Proteins, HCF and Oct-1, on VP16-responsive cis-regulatory elements in HSV immediate-early promoters called TAATGARAT. Comparison of different HSV VP16 sequences reveals a conserved core region that is sufficient for VP16-induced complex formation. The crystal structure of the VP16 core has been determined at 2.1 A resolution. The results reveal a novel, seat-like Protein structure. Together with the activity of mutant VP16 Proteins, the structure of free VP16 suggests that it contains (1) a disordered carboxy-terminal region that associates with HCF, Oct-1, and DNA in the VP16-induced complex, and (2) a structured region involved in virion assembly and possessing a novel DNA-binding surface that differentiates among TAATGARAT VP16-response elements.
Yukihiro Nishiyama - One of the best experts on this subject based on the ideXlab platform.
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Herpes simplex virus type 1 UL14 tegument Protein regulates intracellular compartmentalization of major tegument Protein VP16
Virology journal, 2011Co-Authors: Akane Ohta, Yohei Yamauchi, Yoshifumi Muto, Hiroshi Kimura, Yukihiro NishiyamaAbstract:Background Herpes simplex virus type 1 (HSV-1) has a complicated life-cycle, and its genome encodes many components that can modify the cellular environment to facilitate efficient viral replication. The Protein UL14 is likely involved in viral maturation and egress (Cunningham C. et al), and it facilitates the nuclear translocation of viral capsids and the tegument Protein VP16 during the immediate-early phase of infection (Yamauchi Y. et al, 2008). UL14 of herpes simplex virus type 2 exhibits multiple functions (Yamauchi Y. et al, 2001, 2002, 2003).
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Herpes simplex virus type 1 UL14 tegument Protein regulates intracellular compartmentalization of major tegument Protein VP16
Virology Journal, 2011Co-Authors: Akane Ohta, Yohei Yamauchi, Yoshifumi Muto, Hiroshi Kimura, Yukihiro NishiyamaAbstract:Background Herpes simplex virus type 1 (HSV-1) has a complicated life-cycle, and its genome encodes many components that can modify the cellular environment to facilitate efficient viral replication. The Protein UL14 is likely involved in viral maturation and egress (Cunningham C. et al), and it facilitates the nuclear translocation of viral capsids and the tegument Protein VP16 during the immediate-early phase of infection (Yamauchi Y. et al, 2008). UL14 of herpes simplex virus type 2 exhibits multiple functions (Yamauchi Y. et al, 2001, 2002, 2003). Methods To better understand the function(s) of UL14, we generated VP16-GFP-incorporated UL14-mutant viruses with either single (K51M) or triple (R60A, R64A, E68D) amino acid substitutions in the heat shock Protein (HSP)-like sequence of UL14. We observed the morphology of cells infected with UL14-null virus and amino acid-substituted UL14-mutant viruses at different time points after infection. Results UL14(3P)-VP16GFP and UL14D-VP16GFP (UL14-null) viruses caused similar defects with respect to growth kinetics, compartmentalization of tegument Proteins, and cellular morphology in the late phase. Both the UL14D-VP16GFP and UL14(3P)-VP16GFP viruses led to the formation of an aggresome that incorporated some tegument Proteins but did not include nuclear-egressed viral capsids. Conclusions Our findings suggest that a cluster of charged residues within the HSP-like sequence of UL14 is important for the molecular chaperone-like functions of UL14, and this activity is required for the acquisition of functionality of VP16 and UL46. In addition, UL14 likely contributes to maintaining cellular homeostasis following infection, including cytoskeletal organization. However, direct interactions between UL14 and VP16, UL46, or other cellular or viral Proteins remain unclear.
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Synthesis, subcellular localization and VP16 interaction of the herpes simplex virus type 2 UL46 gene product.
Archives of virology, 2000Co-Authors: Kentaro Kato, Tohru Daikoku, Fumi Goshima, H Kume, Kenichi Yamaki, Yukihiro NishiyamaAbstract:We developed a rabbit polyclonal antiserum reactive against a recombinant 6x His-UL46 fusion Protein expressed in Escherichia coli, and using this antiserum identified the UL46 gene product of herpes simplex virus type 2 (HSV-2) to be phosphoProteins with apparent molecular masses of 82-, 84-, and 86-kDa in infected Vero cells. The UL46 Protein was produced in the late phase of infection in a manner highly dependent on viral DNA synthesis, and was mainly distributed at the edge of the nucleus in the cytoplasm. Although its kinetics of production and its progress of distribution were different from those of the major tegument Protein VP16 (the UL48 gene product or alpha-trans-inducing factor (alphaTIF)), most of the UL46 Protein colocalized with VP16 in the late phase of infection, and copurified with it in column chromatography. Moreover, our data showed that the HSV-2 UL46 Protein, when coexpressed with VP16, enhanced alpha4 promotor-regulated gene expression in a transient luciferase reporter assay, while the expression of the UL46 Protein alone suppressed it.
Steven J. Triezenberg - One of the best experts on this subject based on the ideXlab platform.
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C-Terminal trans-activation sub-region of VP16 is uniquely required for forskolin-induced herpes simplex virus type 1 reactivation from quiescently infected-PC12 cells but not for replication in neuronally differentiated-PC12 cells
Journal of NeuroVirology, 2013Co-Authors: Robert J. Danaher, Chunmei Wang, Ross K. Cook, Steven J. Triezenberg, Robert J. Jacob, Craig S. MillerAbstract:The HSV-1 tegument Protein VP16 contains a trans-activation domain (TAD) that is required for induction of immediate early (IE) genes during lytic infection and induced reactivation from latency. Here we report the differential contributions of the two sub-regions of the TAD in neuronal and non-neuronal cells during activation of IE gene expression, virus replication, and reactivation from quiescently infected (QIF)-PC12 cells. Our studies show that VP16- and chemical (hexamethylenebisacetamide)-induced IE gene activation is attenuated in neuronal cells. Irrespective of neuronal or non-neuronal cell backgrounds, IE gene activation demonstrated a greater requirement for the N-terminal sub-region of VP16 TAD (VP16N) than the C-terminal sub-region (VP16C). In surprising contrast to these findings, a recombinant virus (RP4) containing the VP16N deletion was capable of modest forskolin-induced reactivation whereas a recombinant (RP3) containing a deletion of VP16C was incapable of stress-induced reactivation from QIF-PC12 cells. These unique process-dependent functions of the VP16 TAD sub-regions may be important during particular stages of the virus life cycle (lytic, entrance, and maintenance of a quiescent state and reactivation) when viral DNA would be expected to be differentially modified.
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VP16 serine 375 is a critical determinant of herpes simplex virus exit from latency in vivo
Journal of NeuroVirology, 2011Co-Authors: Nancy M. Sawtell, Steven J. Triezenberg, Richard L. ThompsonAbstract:Development of novel prevention and treatment strategies for herpes simplex virus (HSV) mediated diseases is dependent upon an accurate understanding of the central molecular events underlying the regulation of latency and reactivation. We have recently shown that the transactivation function of the virion Protein VP16 is a critical determinant in the exit from latency in vivo. HSV-1 strain SJO2 carries a single serine to alanine substitution at position 375 in VP16 which disrupts its interaction with its essential co-activator Oct-1. Here we report that SJO2 is severely impaired in its ability to exit latency in vivo. This result reinforces our prior observations with VP16 transactivation mutant, in1814, in which VP16 interaction with Oct-1 is also disrupted and solidifies the importance of the VP16–Oct-1 interaction in the early steps in HSV-1 reactivation.
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curcumin inhibits herpes simplex virus immediate early gene expression by a mechanism independent of p300 cbp histone acetyltransferase activity
Virology, 2008Co-Authors: Sebla B Kutluay, Steven J. Triezenberg, James R Doroghazi, Martha E RoemerAbstract:Curcumin, a phenolic compound from the curry spice turmeric, exhibits a wide range of activities in eukaryotic cells, including antiviral effects that are at present incompletely characterized. Curcumin is known to inhibit the histone acetyltransferase activity of the transcriptional coactivator Proteins p300 and CBP, which are recruited to the immediate early (IE) gene promoters of herpes simplex virus type 1 (HSV-1) by the viral transactivator Protein VP16. We tested the hypothesis that curcumin, by inhibiting these coactivators, would block viral infection and gene expression. In cell culture assays, curcumin significantly decreased HSV-1 infectivity and IE gene expression. Entry of viral DNA to the host cell nucleus and binding of VP16 to IE gene promoters was not affected by curcumin, but recruitment of RNA polymerase II to those promoters was significantly diminished. However, these effects were observed using lower curcumin concentrations than those required to substantially inhibit global H3 acetylation. No changes were observed in histone H3 occupancy or acetylation at viral IE gene promoters. Furthermore, p300 and CBP recruitment to IE gene promoters was not affected by the presence of curcumin. Finally, disruption of p300 expression using a short hairpin RNA did not affect viral IE gene expression. These results suggest that curcumin affects VP16-mediated recruitment of RNA polymerase II to IE gene promoters by a mechanism independent of p300/CBP histone acetyltransferase activity.
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Curcumin inhibits herpes simplex virus immediate-early gene expression by a mechanism independent of p300/CBP histone acetyltransferase activity.
Virology, 2008Co-Authors: Sebla B Kutluay, James R Doroghazi, Martha E Roemer, Steven J. TriezenbergAbstract:Curcumin, a phenolic compound from the curry spice turmeric, exhibits a wide range of activities in eukaryotic cells, including antiviral effects that are at present incompletely characterized. Curcumin is known to inhibit the histone acetyltransferase activity of the transcriptional coactivator Proteins p300 and CBP, which are recruited to the immediate early (IE) gene promoters of herpes simplex virus type 1 (HSV-1) by the viral transactivator Protein VP16. We tested the hypothesis that curcumin, by inhibiting these coactivators, would block viral infection and gene expression. In cell culture assays, curcumin significantly decreased HSV-1 infectivity and IE gene expression. Entry of viral DNA to the host cell nucleus and binding of VP16 to IE gene promoters was not affected by curcumin, but recruitment of RNA polymerase II to those promoters was significantly diminished. However, these effects were observed using lower curcumin concentrations than those required to substantially inhibit global H3 acetylation. No changes were observed in histone H3 occupancy or acetylation at viral IE gene promoters. Furthermore, p300 and CBP recruitment to IE gene promoters was not affected by the presence of curcumin. Finally, disruption of p300 expression using a short hairpin RNA did not affect viral IE gene expression. These results suggest that curcumin affects VP16-mediated recruitment of RNA polymerase II to IE gene promoters by a mechanism independent of p300/CBP histone acetyltransferase activity.
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VP16 dependent association of chromatin modifying coactivators and underrepresentation of histones at immediate early gene promoters during herpes simplex virus infection
Journal of Virology, 2004Co-Authors: Francisco J Herrera, Steven J. TriezenbergAbstract:During infection by herpes simplex virus type 1 (HSV-1), the virion Protein VP16 activates the transcription of viral immediate-early (IE) genes. Genetic and biochemical assays have shown that the potent transcriptional activation domain of VP16 can associate with general transcription factors and with chromatin-modifying coactivator Proteins of several types. The latter interactions are particularly intriguing because previous reports indicate that HSV-1 DNA does not become nucleosomal during lytic infection. In the present work, chemical cross-linking and immunoprecipitation assays were used to probe the presence of activators, general transcription factors, and chromatin-modifying coactivators at IE gene promoters during infection of HeLa cells by wild-type HSV-1 and by RP5, a viral strain lacking the VP16 transcriptional activation domain. The presence of VP16 and Oct-1 at IE promoters did not depend on the activation domain. In contrast, association of RNA polymerase II, TATA-binding Protein, histone acetyltransferases (p300 and CBP), and ATP-dependent remodeling Proteins (BRG1 and hBRM) with IE gene promoters was observed in wild-type infections but was absent or reduced in cells infected by RP5. In contrast to the previous evidence for nonnucleosomal HSV-1 DNA, histone H3 was found associated with viral DNA at early times of infection. Interestingly, histone H3 was underrepresented on IE promoters in a manner dependent on the VP16 activation domain. Thus, the VP16 activation domain is responsible for recruiting general transcription factors and coactivators to IE promoters and also for dramatically reducing the association of histones with those promoters.
Jeffrey I. Cohen - One of the best experts on this subject based on the ideXlab platform.
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Hydrophobic cluster analysis predicts an amino-terminal domain of varicella-zoster virus open reading frame 10 required for transcriptional activation.
Proceedings of the National Academy of Sciences of the United States of America, 1995Co-Authors: Hiroyuki Moriuchi, Steven J. Triezenberg, Masako Moriuchi, Rath Pichyangkura, Sharon E. Straus, Jeffrey I. CohenAbstract:Abstract Varicella-zoster virus open reading frame 10 (ORF10) Protein, the homolog of the herpes simplex virus Protein VP16, can transactivate immediate-early promoters from both viruses. A Protein sequence comparison procedure termed hydrophobic cluster analysis was used to identify a motif centered at Phe-28, near the amino terminus of ORF10, that strongly resembles the sequence of the activating domain surrounding Phe-442 of VP16. With a series of GAL4-ORF10 fusion Proteins, we mapped the ORF10 transcriptional-activation domain to the amino-terminal region (aa 5-79). Extensive mutagenesis of Phe-28 in GAL4-ORF10 fusion Proteins demonstrated the importance of an aromatic or bulky hydrophobic amino acid at this position, as shown previously for Phe-442 of VP16. Transactivation by the native ORF10 Protein was abolished when Phe-28 was replaced by Ala. Similar amino-terminal domains were identified in the VP16 homologs of other alphaherpesviruses. Hydrophobic cluster analysis correctly predicted activation domains of ORF10 and VP16 that share critical characteristics of a distinctive subclass of acidic activation domains.
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Varicella-zoster virus open reading frame 10 Protein, the herpes simplex virus VP16 homolog, transactivates herpesvirus immediate-early gene promoters.
Journal of virology, 1993Co-Authors: Hiroyuki Moriuchi, Masako Moriuchi, Sharon E. Straus, Jeffrey I. CohenAbstract:The varicella-zoster virus (VZV) open reading frame 10 (ORF10) Protein is the homolog of the herpes simplex virus type 1 (HSV-1) Protein VP16. These are two virion tegument Proteins that have extensive amino acid sequence identity in their amino-terminal and middle domains. ORF10, however, lacks the acidic carboxy terminus which is critical for transactivation by VP16. Earlier studies showed that VZV ORF10 does not form a tertiary complex with the TAATGARAT regulatory element (where R is a purine) with which HSV-1 VP16 interacts, suggesting that ORF10 may not have transactivating ability. Using transient-expression assays, we show that VZV ORF10 is able to transactivate VZV immediate-early (IE) gene (ORF62) and HSV-1 IE gene (ICP4 and ICP0) promoters. Furthermore, cell lines stably expressing ORF10 complement the HSV-1 mutant in1814, which lacks the transactivating function of VP16, and enhance the de novo synthesis of infectious virus following transfection of HSV-1 virion DNA. These results indicate that ORF10, like its HSV-1 homolog VP16, is a transactivating Protein despite the absence of sequences similar to the VP16 carboxy-terminal domain. The transactivating function of the VZV ORF10 tegument Protein may be critical for efficient initiation of viral infection.
Hiroyuki Moriuchi - One of the best experts on this subject based on the ideXlab platform.
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Hydrophobic cluster analysis predicts an amino-terminal domain of varicella-zoster virus open reading frame 10 required for transcriptional activation.
Proceedings of the National Academy of Sciences of the United States of America, 1995Co-Authors: Hiroyuki Moriuchi, Steven J. Triezenberg, Masako Moriuchi, Rath Pichyangkura, Sharon E. Straus, Jeffrey I. CohenAbstract:Abstract Varicella-zoster virus open reading frame 10 (ORF10) Protein, the homolog of the herpes simplex virus Protein VP16, can transactivate immediate-early promoters from both viruses. A Protein sequence comparison procedure termed hydrophobic cluster analysis was used to identify a motif centered at Phe-28, near the amino terminus of ORF10, that strongly resembles the sequence of the activating domain surrounding Phe-442 of VP16. With a series of GAL4-ORF10 fusion Proteins, we mapped the ORF10 transcriptional-activation domain to the amino-terminal region (aa 5-79). Extensive mutagenesis of Phe-28 in GAL4-ORF10 fusion Proteins demonstrated the importance of an aromatic or bulky hydrophobic amino acid at this position, as shown previously for Phe-442 of VP16. Transactivation by the native ORF10 Protein was abolished when Phe-28 was replaced by Ala. Similar amino-terminal domains were identified in the VP16 homologs of other alphaherpesviruses. Hydrophobic cluster analysis correctly predicted activation domains of ORF10 and VP16 that share critical characteristics of a distinctive subclass of acidic activation domains.
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Varicella-zoster virus open reading frame 10 Protein, the herpes simplex virus VP16 homolog, transactivates herpesvirus immediate-early gene promoters.
Journal of virology, 1993Co-Authors: Hiroyuki Moriuchi, Masako Moriuchi, Sharon E. Straus, Jeffrey I. CohenAbstract:The varicella-zoster virus (VZV) open reading frame 10 (ORF10) Protein is the homolog of the herpes simplex virus type 1 (HSV-1) Protein VP16. These are two virion tegument Proteins that have extensive amino acid sequence identity in their amino-terminal and middle domains. ORF10, however, lacks the acidic carboxy terminus which is critical for transactivation by VP16. Earlier studies showed that VZV ORF10 does not form a tertiary complex with the TAATGARAT regulatory element (where R is a purine) with which HSV-1 VP16 interacts, suggesting that ORF10 may not have transactivating ability. Using transient-expression assays, we show that VZV ORF10 is able to transactivate VZV immediate-early (IE) gene (ORF62) and HSV-1 IE gene (ICP4 and ICP0) promoters. Furthermore, cell lines stably expressing ORF10 complement the HSV-1 mutant in1814, which lacks the transactivating function of VP16, and enhance the de novo synthesis of infectious virus following transfection of HSV-1 virion DNA. These results indicate that ORF10, like its HSV-1 homolog VP16, is a transactivating Protein despite the absence of sequences similar to the VP16 carboxy-terminal domain. The transactivating function of the VZV ORF10 tegument Protein may be critical for efficient initiation of viral infection.
