scholarly journals The bovine herpesvirus 1 gene encoding infected cell protein 0 (bICP0) can inhibit interferon-dependent transcription in the absence of other viral genes

2005 ◽  
Vol 86 (10) ◽  
pp. 2697-2702 ◽  
Author(s):  
Gail Henderson ◽  
Yange Zhang ◽  
Clinton Jones
Keyword(s):  
Gene Expression ◽  
Ring Finger ◽  
Viral Gene Expression ◽  
Bovine Herpesvirus ◽  
Productive Infection ◽  
Cell Protein ◽  
Viral Gene ◽  
Bovine Herpesvirus 1 ◽  
Infected Cell Protein ◽  
Herpesvirus 1

The infected cell protein 0 (bICP0) encoded by Bovine herpesvirus 1 (BHV-1) stimulates viral gene expression and productive infection. As bICP0 is expressed constitutively during productive infection, it is considered to be the major viral regulatory protein. Like other alphaherpesvirus ICP0 homologues, bICP0 contains a zinc RING finger near its N terminus that activates transcription and regulates subcellular localization. In this study, evidence is provided that bICP0 represses the human beta interferon (IFN-β) promoter and a simple promoter with consensus IFN-stimulated response elements following stimulation with double-stranded RNA (polyinosinic–polycytidylic acid), IFN regulatory factor 3 (IRF3) or IRF7. bICP0 also inhibits the ability of two protein kinases (TBK1 and IKKε) to activate IFN-β promoter activity. The zinc RING finger is necessary for inhibiting IFN-dependent transcription in certain cell types. Collectively, these studies suggest that bICP0 activates productive infection by stimulating viral gene expression and inhibiting IFN-dependent transcription.

scholarly journals Two Pioneer Transcription Factors, Krüppel-Like Transcription Factor 4 and Glucocorticoid Receptor, Cooperatively Transactivate the Bovine Herpesvirus 1 ICP0 Early Promoter and Stimulate Productive Infection

2019 ◽  
Vol 94 (4) ◽  
Author(s):  
Fouad S. El-mayet ◽  
Laximan Sawant ◽  
Prasanth Thunuguntla ◽  
Jing Zhao ◽  
Clinton Jones
Keyword(s):  
Transcription Factors ◽  
Glucocorticoid Receptor ◽  
Viral Gene Expression ◽  
Bovine Herpesvirus ◽  
Transcription Unit ◽  
Productive Infection ◽  
Cell Protein ◽  
Viral Gene ◽  
Bovine Herpesvirus 1 ◽  
Herpesvirus 1

ABSTRACT An important site for bovine herpesvirus 1 (BoHV-1) latency is sensory neurons within trigeminal ganglia (TG). The synthetic corticosteroid dexamethasone consistently induces BoHV-1 reactivation from latency. Expression of four Krüppel-like transcription factors (KLF), i.e., KLF4, KLF6, PLZF (promyelocytic leukemia zinc finger), and KLF15, are induced in TG neurons early during dexamethasone-induced reactivation. The glucocorticoid receptor (GR) and KLF15 form a feed-forward transcription loop that cooperatively transactivates the BoHV-1 immediate early transcription unit 1 (IEtu1) promoter that drives bovine infected cell protein 0 (bICP0) and bICP4 expression. Since the bICP0 gene also contains a separate early (E) promoter, we tested the hypothesis that GR and KLF family members transactivate the bICP0 E promoter. GR and KLF4, both pioneer transcription factors, cooperated to stimulate bICP0 E promoter activity in a ligand-independent manner in mouse neuroblastoma cells (Neuro-2A). Furthermore, GR and KLF4 stimulated productive infection. Mutating both half GR binding sites did not significantly reduce GR- and KLF4-mediated transactivation of the bICP0 E promoter, suggesting that a novel mechanism exists for transactivation. GR and KLF15 cooperatively stimulated bICP0 activity less efficiently than GR and KL4: however, KLF6, PLZF, and GR had little effect on the bICP0 E promoter. GR, KLF4, and KLF15 occupied bICP0 E promoter sequences in transfected Neuro-2A cells. GR and KLF15, but not KLF4, occupied the bICP0 E promoter at late times during productive infection of bovine cells. Collectively, these studies suggest that cooperative transactivation of the bICP0 E promoter by two pioneer transcription factors (GR and KLF4) correlates with stimulating lytic cycle viral gene expression following stressful stimuli. IMPORTANCE Bovine herpesvirus 1 (BoHV-1), an important bovine pathogen, establishes lifelong latency in sensory neurons. Reactivation from latency is consistently induced by the synthetic corticosteroid dexamethasone. We predict that increased corticosteroid levels activate the glucocorticoid receptor (GR). Consequently, viral gene expression is stimulated by the activated GR. The immediate early transcription unit 1 promoter (IEtu1) drives expression of two viral transcriptional regulatory proteins, bovine infected cell protein 0 (bICP0) and bICP4. Interestingly, a separate early promoter also drives bICP0 expression. Two pioneer transcription factors, GR and Krüppel-like transcription factor 4 (KLF4), cooperatively transactivate the bICP0 early (E) promoter. GR and KLF15 cooperate to stimulate bICP0 E promoter activity but significantly less than GR and KLF4. The bICP0 E promoter contains enhancer-like domains necessary for GR- and KLF4-mediated transactivation that are distinct from those for GR and KLF15. Stress-induced pioneer transcription factors are proposed to activate key viral promoters, including the bICP0 E promoter, during early stages of reactivation from latency.

scholarly journals Combinatorial Effects of the Glucocorticoid Receptor and Krüppel-Like Transcription Factor 15 on Bovine Herpesvirus 1 Transcription and Productive Infection

2017 ◽  
Vol 91 (21) ◽  
Author(s):  
Fouad S. El-mayet ◽  
Laximan Sawant ◽  
Prasanth Thunuguntla ◽  
Clinton Jones
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Glucocorticoid Receptor ◽  
Sensory Neurons ◽  
Viral Gene Expression ◽  
Bovine Herpesvirus ◽  
Productive Infection ◽  
Viral Gene ◽  
Bovine Herpesvirus 1 ◽  
Herpesvirus 1

ABSTRACT Bovine herpesvirus 1 (BoHV-1), an important bovine pathogen, establishes lifelong latency in sensory neurons. Latently infected calves consistently reactivate from latency following a single intravenous injection of the synthetic corticosteroid dexamethasone. The immediate early transcription unit 1 (IEtu1) promoter, which drives bovine ICP0 (bICP0) and bICP4 expression, is stimulated by dexamethasone because it contains two glucocorticoid receptor (GR) response elements (GREs). Several Krüppel-like transcription factors (KLF), including KLF15, are induced during reactivation from latency, and they stimulate certain viral promoters and productive infection. In this study, we demonstrate that the GR and KLF15 were frequently expressed in the same trigeminal ganglion (TG) neuron during reactivation and cooperatively stimulated productive infection and IEtu1 GREs in mouse neuroblastoma cells (Neuro-2A). We further hypothesized that additional regions in the BoHV-1 genome are transactivated by the GR or stress-induced transcription factors. To test this hypothesis, BoHV-1 DNA fragments (less than 400 bp) containing potential GR and KLF binding sites were identified and examined for transcriptional activation by stress-induced transcription factors. Intergenic regions within the unique long 52 gene (UL52; a component of the DNA primase/helicase complex), bICP4, IEtu2, and the unique short region were stimulated by KLF15 and the GR. Chromatin immunoprecipitation studies revealed that the GR and KLF15 interacted with sequences within IEtu1 GREs and the UL52 fragment. Coimmunoprecipitation studies demonstrated that KLF15 and the GR were associated with each other in transfected cells. Since the GR stimulates KLF15 expression, we suggest that these two transcription factors form a feed-forward loop that stimulates viral gene expression and productive infection following stressful stimuli. IMPORTANCE Bovine herpesvirus 1 (BoHV-1) is an important viral pathogen that causes respiratory disease and suppresses immune responses in cattle; consequently, life-threatening bacterial pneumonia can occur. Following acute infection, BoHV-1 establishes lifelong latency in sensory neurons. Reactivation from latency is initiated by the synthetic corticosteroid dexamethasone. Dexamethasone stimulates lytic cycle viral gene expression in sensory neurons of calves latently infected with BoHV-1, culminating in virus shedding and transmission. Two stress-induced cellular transcription factors, Krüppel-like transcription factor 15 (KLF15) and the glucocorticoid receptor (GR), cooperate to stimulate productive infection and viral transcription. Additional studies demonstrated that KLF15 and the GR form a stable complex and that these stress-induced transcription factors bind to viral DNA sequences, which correlates with transcriptional activation. The ability of the GR and KLF15 to synergistically stimulate viral gene expression and productive infection may be critical for the ability of BoHV-1 to reactivate from latency following stressful stimuli.

scholarly journals The Infected Cell Protein 0 Encoded by Bovine Herpesvirus 1 (bICP0) Associates with Interferon Regulatory Factor 7 and Consequently Inhibits Beta Interferon Promoter Activity

2009 ◽  
Vol 83 (8) ◽  
pp. 3977-3981 ◽  
Author(s):  
Kazima Saira ◽  
You Zhou ◽  
Clinton Jones
Keyword(s):  
Promoter Activity ◽  
Viral Gene Expression ◽  
Bovine Herpesvirus ◽  
Productive Infection ◽  
Cell Protein ◽  
Viral Gene ◽  
Regulatory Factor ◽  
Bovine Herpesvirus 1 ◽  
Protein Levels ◽  
Herpesvirus 1

ABSTRACT The bICP0 protein encoded by bovine herpesvirus 1 stimulates productive infection and viral gene expression but inhibits interferon (IFN)-dependent transcription. bICP0 inhibits beta IFN (IFN-β) promoter activity and induces degradation of IFN regulatory factor 3 (IRF3). Although bICP0 inhibits the trans-activation activity of IRF7, IRF7 protein levels are not reduced. In this study, we demonstrate that bICP0 is associated with IRF7. Furthermore, bICP0 inhibits the ability of IRF7 to trans-activate the IFN-β promoter in the absence of IRF3 expression. The interaction between bICP0 and IRF7 correlates with reduced trans-activation of the IFN-β promoter by IRF7.

scholarly journals The Zinc RING Finger of Bovine Herpesvirus 1-Encoded bICP0 Protein Is Crucial for Viral Replication and Virulence

2008 ◽  
Vol 82 (24) ◽  
pp. 12060-12068 ◽  
Author(s):  
Kazima Saira ◽  
Shafiqul Chowdhury ◽  
Natasha Gaudreault ◽  
Leticia da Silva ◽  
Gail Henderson ◽  
...  
Keyword(s):  
Amino Acid ◽  
Ring Finger ◽  
Bovine Herpesvirus ◽  
Mutant Virus ◽  
Productive Infection ◽  
Single Amino Acid ◽  
Cell Protein ◽  
Bovine Herpesvirus 1 ◽  
Latently Infected ◽  
Herpesvirus 1

ABSTRACT Bovine herpesvirus 1 (BHV-1) infected cell protein 0 (bICP0) stimulates productive infection, in part by activating viral gene expression. The C3HC4 zinc RING finger of bICP0 is crucial for activating viral transcription and productive infection. In this study, we used a bacterial artificial chromosome containing a wild-type (wt) virulent BHV-1 strain to generate a single amino acid mutation in the C3HC4 zinc RING finger of bICP0. This virus (the 51g mutant) contains a cysteine-to-glycine mutation (51st amino acid) in the C3HC4 zinc RING finger of bICP0. A plasmid expressing the 51g mutant protein did not transactivate viral promoter activity as efficiently as wt bICP0. The 51g mutant virus expressed higher levels of the bICP0 protein than did the 51g rescued virus (51gR) but yielded reduced virus titers following infection of permissive bovine cells. The 51g mutant virus, but not the 51gR virus, grew poorly in bovine cells pretreated with imiquimod to stimulate interferon production. During acute infection of calves, levels of infectious virus were 2 to 3 logs lower in ocular or nasal swabs with 51g than with 51gR. Calves latently infected with the 51g mutant did not reactivate from latency because virus shedding did not occur in ocular or nasal cavities. As expected, calves latently infected with 51gR reactivated from latency following dexamethasone treatment. These studies demonstrate that mutation of a single well-conserved cysteine residue in the C3HC4 zinc RING finger of bICP0 has dramatic effects on the growth properties of BHV-1.

scholarly journals The Bovine Herpesvirus 1 Immediate-Early Protein (bICP0) Associates with Histone Deacetylase 1 To Activate Transcription

2001 ◽  
Vol 75 (20) ◽  
pp. 9571-9578 ◽  
Author(s):  
Yange Zhang ◽  
Clinton Jones
Keyword(s):  
Histone Deacetylase ◽  
Transcriptional Repression ◽  
Ring Finger ◽  
Bovine Herpesvirus ◽  
Productive Infection ◽  
Cell Protein ◽  
Bovine Herpesvirus 1 ◽  
Histone Deacetylase 1 ◽  
Early Protein ◽  
Herpesvirus 1

ABSTRACT Infected-cell protein 0 encoded by bovine herpesvirus 1 (BHV-1) (bICP0) is necessary for efficient productive infection, in large part, because it activates all 3 classes of BHV-1 genes (U. V. Wirth, C. Fraefel, B. Vogt, C. Vlcek, V. Paces, and M. Schwyzer, J. Virol. 66:2763–2772, 1992). Although bICP0 is believed to be a functional homologue of herpes simplex virus type 1-encoded ICP0, the only well-conserved domain between the proteins is a zinc ring finger located near the amino terminus of both proteins. Our previous studies demonstrated that bICP0 is toxic to transfected cells but does not appear to directly induce apoptosis (Inman, M., Y. Zhang, V. Geiser, and C. Jones, J. Gen. Virol. 82:483–492, 2001). C-terminal sequences in the last 320 amino acids of bICP0 mediate subcellular localization. Mutagenesis of the zinc ring finger within bICP0 revealed that this domain was important for transcriptional activation. In this study, we demonstrate that bICP0 interacts with histone deacetylase 1 (HDAC1), which results in activation of a simple promoter containing four consensus Myc-Max binding sites. The interaction between bICP0 and HDAC1 correlated with inhibition of Mad-dependent transcriptional repression. In resting CV-1 cells, bICP0 relieved HDAC1-mediated transcriptional repression. The zinc ring finger was required for relieving HDAC1-induced repression but not for interacting with HDAC1. In fetal bovine lung cells but not in a human epithelial cell line, bICP0 expression correlated with reduced steady-state levels of HDAC1 in crude cytoplasmic extracts. We hypothesize that the ability of bICP0 to overcome HDAC1-induced repression plays a role in promoting productive infection in highly differentiated cell types.

scholarly journals The latency-related gene of bovine herpesvirus-1 can inhibit the ability of bICP0 to activate productive infection

2002 ◽  
Vol 83 (12) ◽  
pp. 2965-2971 ◽  
Author(s):  
Vicki Geiser ◽  
Melissa Inman ◽  
Yange Zhang ◽  
Clinton Jones
Keyword(s):  
Protein Expression ◽  
Viral Gene Expression ◽  
Bovine Herpesvirus ◽  
Productive Infection ◽  
Viral Gene ◽  
Bovine Herpesvirus 1 ◽  
Dose Dependent Fashion ◽  
Herpesvirus 1 ◽  
Low Levels ◽  
Dose Dependent

Transfection of bovine cells with bovine herpesvirus-1 genomic DNA yields low levels of infectious virus. Cotransfection with the bICP0 gene enhances productive infection and virus yield because bICP0 can activate viral gene expression. Since the latency-related (LR) gene overlaps and is antisense to bICP0, the effects of LR gene products on productive infection were tested. The intact LR gene inhibited productive infection in a dose-dependent fashion but LR protein expression was not required. Further studies indicated that LR gene sequences near the 3′ terminus of the LR RNA are necessary for inhibiting productive infection. When cotransfected with the bICP0 gene, the LR gene inhibited bICP0 RNA and protein expression in transiently transfected cells. Taken together, these results suggest that abundant LR RNA expression in sensory neurons is one factor that has the potential to inhibit productive infection and consequently promote the establishment and maintenance of latency.

scholarly journals Analysis of a bovine herpesvirus 1 recombinant virus that does not express the bICP0 protein

2005 ◽  
Vol 86 (7) ◽  
pp. 1987-1996 ◽  
Author(s):  
V. Geiser ◽  
Y. Zhang ◽  
C. Jones
Keyword(s):  
Point Mutation ◽  
Recombinant Virus ◽  
Ring Finger ◽  
Bovine Herpesvirus ◽  
Mutant Virus ◽  
Productive Infection ◽  
Cell Protein ◽  
Null Mutant ◽  
Bovine Herpesvirus 1 ◽  
Herpesvirus 1

Bovine herpesvirus 1 (BHV-1) infected-cell protein 0 (bICP0) stimulates productive infection by activating viral gene expression. In this study, an attempt was made to construct a recombinant virus with point mutations in the C3HC4 zinc RING finger of bICP0, as this domain is necessary for activating viral transcription and productive infection. A virus was identified in bovine cells that induced small clusters of infected cells resembling a small plaque. Instead of the expected mutations within the zinc RING finger, this virus contained a point mutation within the initiating ATG of bICP0, a point mutation two bases downstream from the ATG mutation and deletion of flanking plasmid sequences used for homologous recombination. The bICP0 mutant was rescued with wild-type (wt) bICP0 sequences and the bICP0-rescued virus produced wt plaques. The bICP0-rescued virus and wt BHV-1, but not the mutant, expressed the bICP0 protein during productive infection of bovine cells, suggesting that the mutant virus was a null mutant. Consequently, the mutant was designated the bICP0 null mutant. Infection of bovine cells with the bICP0 null mutant resulted in at least 100-fold lower virus titres, indicating that bICP0 protein expression is important, but not required, for virus production. When bovine cells infected with the bICP0 null mutant virus were subcultured, the cells continued to divide, but viral DNA could be detected after more than 35 passages, suggesting that the bICP0 null mutant induced a persistent-like infection in bovine cells and that it may be useful for generating additional bICP0 mutants.

scholarly journals The Cellular Coactivator HCF-1 Is Required for Glucocorticoid Receptor-Mediated Transcription of Bovine Herpesvirus 1 Immediate Early Genes

2018 ◽  
Vol 92 (17) ◽  
Author(s):  
Laximan Sawant ◽  
Insun Kook ◽  
Jodi L. Vogel ◽  
Thomas M. Kristie ◽  
Clinton Jones
Keyword(s):  
Gene Expression ◽  
Glucocorticoid Receptor ◽  
Bovine Herpesvirus ◽  
Transcription Unit ◽  
Lytic Infection ◽  
Immediate Early ◽  
Productive Infection ◽  
Core Element ◽  
Bovine Herpesvirus 1 ◽  
Herpesvirus 1

ABSTRACTFollowing productive infection, bovine herpesvirus 1 (BoHV-1) establishes latency in sensory neurons. As in other alphaherpesviruses, expression of BoHV-1 immediate early (IE) genes is regulated by an enhancer complex containing the viral IE activator VP16, the cellular transcription factor Oct-1, and transcriptional coactivator HCF-1, which is assembled on an IE enhancer core element (TAATGARAT). Expression of the IE transcription unit that encodes the viral IE activators bICP0 and bICP4 may also be induced by the activated glucocorticoid receptor (GR) via two glucocorticoid response elements (GREs) located upstream of the enhancer core. Strikingly, lytic infection and reactivation from latency are consistently enhanced by glucocorticoid treatmentin vivo. As the coactivator HCF-1 is essential for IE gene expression of alphaherpesviruses and recruited by multiple transcription factors, we tested whether HCF-1 is required for glucocorticoid-induced IE gene expression. Depletion of HCF-1 reduced GR-mediated activation of the IE promoter in mouse neuroblastoma cells (Neuro-2A). More importantly, HCF-1-mediated GR activation of the promoter was dependent on the presence of GRE sites but independent of the TAATGARAT enhancer core element. HCF-1 was also recruited to the GRE region of a promoter lacking the enhancer core, consistent with a direct role of the coactivator in mediating GR-induced transcription. Similarly, during productive lytic infection, HCF-1 and GR occupied the IE region containing the GREs. These studies indicate HCF-1 is critical for GR activation of the viral IE genes and suggests that glucocorticoid induction of viral reactivation proceeds via an HCF-1–GR mechanism in the absence of the viral IE activator VP16.IMPORTANCEBoHV-1 transcription is rapidly activated during stress-induced reactivation from latency. The immediate early transcription unit 1 (IEtu1) promoter is regulated by the GR via two GREs. The IEtu1 promoter regulates expression of two viral transcriptional regulatory proteins, infected cell proteins 0 and 4 (bICP0 and bICP4), and thus must be stimulated during reactivation. This study demonstrates that activation of the IEtu1 promoter by the synthetic corticosteroid dexamethasone requires HCF-1. Interestingly, the GRE sites, but not the IE enhancer core element (TAATGARAT), were required for HCF-1-mediated GR promoter activation. The GR and HCF-1 were recruited to the IEtu1 promoter in transfected and infected cells. Collectively, these studies indicate that HCF-1 is critical for GR activation of the viral IE genes and suggest that an HCF-1–GR complex can stimulate the IEtu1 promoter in the absence of the viral IE activator VP16.

scholarly journals Identification of functional domains within the bICP0 protein encoded by bovine herpesvirus 1

2005 ◽  
Vol 86 (4) ◽  
pp. 879-886 ◽  
Author(s):  
Yange Zhang ◽  
Joe Zhou ◽  
Clinton Jones
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Ring Finger ◽  
Bovine Herpesvirus ◽  
Productive Infection ◽  
Functional Domains ◽  
Bovine Herpesvirus 1 ◽  
Transposon Insertion ◽  
Localization Signal ◽  
Herpesvirus 1

It is believed that the bICP0 protein encoded by bovine herpesvirus 1 (BoHV-1) stimulates productive infection by activating viral gene expression. Like the other ICP0-like proteins encoded by alphaherpesvirinae subfamily members, bICP0 contains a zinc RING finger near its amino terminus. The zinc RING finger of bICP0 activates viral transcription, stimulates productive infection, and is toxic to certain cell types. Apart from the zinc RING finger, bICP0 possesses little similarity to the herpes simplex virus type 1 ICP0 protein making it difficult to predict what regions of bICP0 are important. To begin to identify bICP0 functional domains that are not part of the zinc RING finger, a panel of transposon insertion mutants that span bICP0 was developed. A large domain spanning aa 78–256, and a separate domain that is at or near aa 457 was necessary for efficient transactivation of a simple promoter. Transposon insertion at aa 91 impaired bICP0 protein stability in transfected cells. Insertion of transposons into the acidic domain of bICP0 had little or no effect on transactivation of a simple promoter or protein expression suggesting this region does not play a major role in activating gene expression. Sequences near the C terminus (aa 607–676) contain a functional nuclear localization signal. Collectively, these studies indicated that bICP0 contains several important functional domains: (i) the zinc RING finger, (ii) two separate domains that activate transcription, and (iii) a C-terminal nuclear localization signal that is also necessary for efficient transactivation.

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