scholarly journals Herpes Simplex Virus Type 1 Blocks the Apoptotic Host Cell Defense Mechanisms That Target Bcl-2 and Manipulates Activation of p38 Mitogen-Activated Protein Kinase To Improve Viral Replication

2001 ◽  
Vol 75 (6) ◽  
pp. 2710-2728 ◽  
Author(s):  
George Zachos ◽  
Margy Koffa ◽  
Chris M. Preston ◽  
J. Barklie Clements ◽  
Joe Conner
Keyword(s):  
Cell Death ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Protein Kinase ◽  
Herpes Simplex Virus Type ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Wild-type (wt) herpes simplex virus type 1 (HSV-1) suppresses cell death. We investigated the apoptotic pathways triggered during infection with mutant viruses tsk and 27lacZ (which lack functional ICP4 and ICP27 viral proteins, respectively) and examined the mechanisms used by wt HSV-1 to protect against programmed cell death induced by the DNA-damaging compound cisplatin. In our studies, we used BHK and HeLa cells, with similar results. We suggest that a decrease in the levels of Bcl-2 protein is a key event during apoptosis induced by the mutant viruses and that Bcl-2 levels are targeted by (i) a decrease of bcl-2 RNA, (ii) caspase-related proteolysis, and (iii) p38 mitogen-activated protein kinase (p38MAPK)-dependent destabilization of Bcl-2 protein. We show that wt HSV-1, but not the mutant viruses, maintains bcl-2 RNA and protein levels during infection and protects from the cisplatin-induced decrease in bcl-2 RNA; our data suggest that both ICP27 and ICP4 are required for this function. Additionally, wt HSV-1 evades but does not actively block activation of caspases. Although wt HSV-1 induces p38MAPK activation during infection, it prevents p38MAPK-dependent destabilization of Bcl-2 and exploits p38MAPK stimulation to enhance transcription of specific viral gene promoters to increase viral yields.

scholarly journals Modification and Reorganization of the Cytoprotective Cellular Chaperone Hsp27 during Herpes Simplex Virus Type 1 Infection

2009 ◽  
Vol 83 (18) ◽  
pp. 9304-9312 ◽  
Author(s):  
Shomita S. Mathew ◽  
Megan P. Della Selva ◽  
April D. Burch
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Capsid Maturation ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Chaperone-enriched domains are formed in the nuclei of cells lytically infected with herpes simplex virus type 1 (HSV-1). These domains, called VICE, for virus induced chaperone enriched, contain Hsc70, Hsp70, Hsp40, Hsp90, polyubiquitinated proteins, and components of the proteasome machinery. Accumulating evidence indicates that these sites may be utilized during infection to sequester misfolded, modified, or otherwise unwanted proteins away from viral replication compartments, sites of robust transcription, DNA synthesis, and capsid maturation. To further explore the role of cellular chaperones and VICE domains during HSV-1 infection, we have analyzed the cytoprotective chaperone Hsp27. Here we present evidence that Hsp27, which is known to possess several antioxidant functions, is rapidly reorganized and modified at early stages in response to HSV-1 infection and signaling from the mitogen-activated protein kinase p38. Immunofluorescence analysis and fractionation experiments reveal disparate subcellular localizations of nonphosphorylated and phosphorylated forms of Hsp27 during wild-type HSV-1 infection. Unmodified forms of Hsp27 are localized in nuclear foci that are outside of replication compartments, adjacent to VICE domains, and in the cytoplasm. Conversely, we find that phosphorylated forms of Hsp27 are localized exclusively in the cytoplasm. Last, in cells depleted of all forms of Hsp27, virus replication is significantly reduced.

scholarly journals Herpes Simplex Virus Type 1 Immediate-Early Protein Vmw110 Induces the Proteasome-Dependent Degradation of the Catalytic Subunit of DNA-Dependent Protein Kinase

1999 ◽  
Vol 73 (1) ◽  
pp. 650-657 ◽  
Author(s):  
Jane Parkinson ◽  
Susan P. Lees-Miller ◽  
Roger D. Everett
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Protein Kinase ◽  
Herpes Simplex Virus Type ◽  
Dependent Protein Kinase ◽  
Early Protein ◽  
Dependent Protein ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Herpes simplex virus type 1 (HSV-1) infection causes the active degradation of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), and this process is reliant on the expression of the HSV-1 immediate-early protein Vmw110. In this study we investigated in more detail the mechanism by which the degradation occurs, the domains of Vmw110 which are required, and whether Vmw110 is by itself sufficient for the effect. We found that proteasome inhibitors prevented the degradation of DNA-PKcs, indicating the involvement of a proteasome pathway. Furthermore, the continued activity of DNA-PK during infection in the presence of these inhibitors indicated that Vmw110 does not directly alter the enzyme activity of DNA-PKcs prior to its degradation in a normal infection. Indeed, Vmw110 was found to bind to neither the catalytic nor Ku subunits of DNA-PK. Using mutant Vmw110 viruses we show that the RING finger domain of Vmw110 is essential for the induced degradation of DNA-PKcs but that the ability of Vmw110 to bind to a cellular ubiquitin-specific protease (HAUSP) is not required. When expressed in the absence of other viral proteins, Vmw110 was sufficient to cause the degradation of DNA-PKcs, indicating that the effect on the stability of DNA-PKcs was a direct consequence of Vmw110 activity and not an indirect Vmw110-dependent effect of virus infection. Finally, the Vmw110-induced degradation of DNA-PKcs and loss in DNA-PK activity appears to be beneficial to HSV-1 infection, as virus replication was more efficient in cells lacking DNA-PKcs, especially at low multiplicities of infection.

scholarly journals Phosphorylation of Structural Components Promotes Dissociation of the Herpes Simplex Virus Type 1 Tegument

1998 ◽  
Vol 72 (9) ◽  
pp. 7108-7114 ◽  
Author(s):  
Ewan E. Morrison ◽  
Yi-Fen Wang ◽  
David M. Meredith
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Protein Kinase ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Structural Components ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT The role of phosphorylation in the dissociation of structural components of the herpes simplex virus type 1 (HSV-1) tegument was investigated, using an in vitro assay. Addition of physiological concentrations of ATP and magnesium to wild-type virions in the presence of detergent promoted the release of VP13/14 and VP22. VP1/2 and the UL13 protein kinase were not significantly solubilized. However, using a virus with an inactivated UL13 protein, we found that the release of VP22 was severely impaired. Addition of casein kinase II (CKII) to UL13 mutant virions promoted VP22 release. Heat inactivation of virions or addition of phosphatase inhibited the release of both proteins. Incorporation of radiolabeled ATP into the assay demonstrated the phosphorylation of VP1/2, VP13/14, VP16, and VP22. Incubation of detergent-purified, heat-inactivated capsid-tegument with recombinant kinases showed VP1/2 phosphorylation by CKII, VP13/14 phosphorylation by CKII, protein kinase A (PKA), and PKC, VP16 phosphorylation by PKA, and VP22 phosphorylation by CKII and PKC. Proteolytic mapping and phosphoamino acid analysis of phosphorylated VP22 correlated with previously published work. The phosphorylation of virion-associated VP13/14, VP16, and VP22 was demonstrated in cells infected in the presence of cycloheximide. Use of equine herpesvirus 1 in the in vitro release assay resulted in the enhanced release of VP10, the homolog of HSV-1 VP13/14. These results suggest that the dissociation of major tegument proteins from alphaherpesvirus virions in infected cells may be initiated by phosphorylation events mediated by both virion-associated and cellular kinases.

scholarly journals Enhanced Phosphorylation of Transcription Factor Sp1 in Response to Herpes Simplex Virus Type 1 Infection Is Dependent on the Ataxia Telangiectasia-Mutated Protein

2007 ◽  
Vol 81 (18) ◽  
pp. 9653-9664 ◽  
Author(s):  
Satoko Iwahori ◽  
Noriko Shirata ◽  
Yasushi Kawaguchi ◽  
Sandra K. Weller ◽  
Yoshitaka Sato ◽  
...  
Keyword(s):  
Dna Damage ◽  
Transcription Factor ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Herpes Simplex Virus Type ◽  
Ataxia Telangiectasia ◽  
Ataxia Telangiectasia Mutated ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT The ataxia telangiectasia-mutated (ATM) protein, a member of the related phosphatidylinositol 3-like kinase family encoded by a gene responsible for the human genetic disorder ataxia telangiectasia, regulates cellular responses to DNA damage and viral infection. It has been previously reported that herpes simplex virus type 1 (HSV-1) infection induces activation of protein kinase activity of ATM and hyperphosphorylation of transcription factor, Sp1. We show that ATM is intimately involved in Sp1 hyperphosphorylation during HSV-1 infection rather than individual HSV-1-encoded protein kinases. In ATM-deficient cells or cells silenced for ATM expression by short hairpin RNA targeting, hyperphosphorylation of Sp1 was prevented even as HSV-1 infection progressed. Mutational analysis of putative ATM phosphorylation sites on Sp1 and immunoblot analysis with phosphopeptide-specific Sp1 antibodies clarified that at least Ser-56 and Ser-101 residues on Sp1 became phosphorylated upon HSV-1 infection. Serine-to-alanine mutations at both sites on Sp1 considerably abolished hyperphosphorylation of Sp1 upon infection. Although ATM phosphorylated Ser-101 but not Ser-56 on Sp1 in vitro, phosphorylation of Sp1 at both sites was not detected at all upon infection in ATM-deficient cells, suggesting that cellular kinase(s) activated by ATM could be involved in phosphorylation at Ser-56. Upon viral infection, Sp1-dependent transcription in ATM expression-silenced cells was almost the same as that in ATM-intact cells, suggesting that ATM-dependent phosphorylation of Sp1 might hardly affect its transcriptional activity during the HSV-1 infection. ATM-dependent Sp1 phosphorylation appears to be a global response to various DNA damage stress including viral DNA replication.

scholarly journals Herpes Simplex Virus Type 1 Evades the Effects of Antibody and Complement In Vivo

2002 ◽  
Vol 76 (18) ◽  
pp. 9232-9241 ◽  
Author(s):  
John M. Lubinski ◽  
Ming Jiang ◽  
Lauren Hook ◽  
Yueh Chang ◽  
Chad Sarver ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Immune Evasion ◽  
Herpes Simplex Virus Type ◽  
Complement Components ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Herpes simplex virus type 1 (HSV-1) encodes a complement-interacting glycoprotein, gC, and an immunoglobulin G (IgG) Fc binding glycoprotein, gE, that mediate immune evasion by affecting multiple aspects of innate and acquired immunity, including interfering with complement components C1q, C3, C5, and properdin and blocking antibody-dependent cellular cytotoxicity. Previous studies evaluated the individual contributions of gC and gE to immune evasion. Experiments in a murine model that examines the combined effects of gC and gE immune evasion on pathogenesis are now reported. Virulence of wild-type HSV-1 is compared with mutant viruses defective in gC-mediated C3 binding, gE-mediated IgG Fc binding, or both immune evasion activities. Eliminating both activities greatly increased susceptibility of HSV-1 to antibody and complement neutralization in vitro and markedly reduced virulence in vivo as measured by disease scores, virus titers, and mortality. Studies with C3 knockout mice indicated that other activities attributed to these glycoproteins, such as gC-mediated virus attachment to heparan sulfate or gE-mediated cell-to-cell spread, do not account for the reduced virulence of mutant viruses. The results support the importance of gC and gE immune evasion in vivo and suggest potential new targets for prevention and treatment of HSV disease.

scholarly journals Nucleolin Is Required for Efficient Nuclear Egress of Herpes Simplex Virus Type 1 Nucleocapsids

2009 ◽  
Vol 84 (4) ◽  
pp. 2110-2121 ◽  
Author(s):  
Ken Sagou ◽  
Masashi Uema ◽  
Yasushi Kawaguchi
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Nuclear Membrane ◽  
Herpes Simplex Virus Type ◽  
Viral Dna ◽  
Nuclear Egress ◽  
Infected Cells ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Herpesvirus nucleocapsids assemble in the nucleus and must cross the nuclear membrane for final assembly and maturation to form infectious progeny virions in the cytoplasm. It has been proposed that nucleocapsids enter the perinuclear space by budding through the inner nuclear membrane, and these enveloped nucleocapsids then fuse with the outer nuclear membrane to enter the cytoplasm. Little is known about the mechanism(s) for nuclear egress of herpesvirus nucleocapsids and, in particular, which, if any, cellular proteins are involved in the nuclear egress pathway. UL12 is an alkaline nuclease encoded by herpes simplex virus type 1 (HSV-1) and has been suggested to be involved in viral DNA maturation and nuclear egress of nucleocapsids. Using a live-cell imaging system to study cells infected by a recombinant HSV-1 expressing UL12 fused to a fluorescent protein, we observed the previously unreported nucleolar localization of UL12 in live infected cells and, using coimmunoprecipitation analyses, showed that UL12 formed a complex with nucleolin, a nucleolus marker, in infected cells. Knockdown of nucleolin in HSV-1-infected cells reduced capsid accumulation, as well as the amount of viral DNA resistant to staphylococcal nuclease in the cytoplasm, which represented encapsidated viral DNA, but had little effect on these viral components in the nucleus. These results indicated that nucleolin is a cellular factor required for efficient nuclear egress of HSV-1 nucleocapsids in infected cells.

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