Herpes simplex virus VP16 forms a complex with the virion host shutoff protein vhs.

ABSTRACT The virion host shutoff protein (vhs) of herpes simplex virus triggers accelerated degradation of cellular and viral mRNAs while sparing other cytoplasmic RNA species. Previous work has shown that vhs forms a complex with translation initiation factor eIF4H, which displays detectable RNase activity in the absence of other viral or host proteins. However, the contributions of eIF4H and other host factors to the activity and mRNA targeting properties of vhs have not yet been directly examined. An earlier report from our laboratory demonstrated that rabbit reticulocyte lysate (RRL) contains one or more factors that strongly stimulate the RNase activity of vhs produced in Saccharomyces cerevisiae. We report here that such yeast extracts display significant vhs-dependent RNase activity in the absence of mammalian factors. This activity differs from that displayed by vhs generated in RRL in that it is not targeted to the encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES). Activity was strongly enhanced by the addition of RRL, eIF4H, or the related translation factor eIF4B. RRL also reconstituted strong targeting to the EMCV IRES, resulting in a major change in the RNA cleavage pattern. In contrast, eIF4H and eIF4B did not reconstitute IRES-directed targeting. These data indicate that eIF4B and 4H stimulate the nuclease activity of vhs, and they provide evidence that additional mammalian factors are required for targeting to the EMCV IRES.

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Construction and properties of a herpes simplex virus 2 dl5-29 vaccine candidate strain encoding an HSV-1 virion host shutoff protein

Vaccine ◽

10.1016/j.vaccine.2010.01.030 ◽

2010 ◽

Vol 28 (15) ◽

pp. 2754-2762 ◽

Cited By ~ 17

Author(s):

Natalia J. Reszka ◽

Timothy Dudek ◽

David M. Knipe

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Vaccine Candidate ◽

Virion Host Shutoff ◽

Virion Host Shutoff Protein ◽

Host Shutoff ◽

Simplex Virus ◽

Herpes Simplex Virus 2 ◽

Candidate Strain ◽

Hsv 1

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Herpes Simplex Virus 2 Virion Host Shutoff Endoribonuclease Activity Is Required To Disrupt Stress Granule Formation

Journal of Virology ◽

10.1128/jvi.00947-16 ◽

2016 ◽

Vol 90 (17) ◽

pp. 7943-7955 ◽

Cited By ~ 14

Author(s):

Renée L. Finnen ◽

Mingzhao Zhu ◽

Jing Li ◽

Daniel Romo ◽

Bruce W. Banfield

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Stress Granules ◽

Granule Formation ◽

Virion Host Shutoff ◽

Virion Host Shutoff Protein ◽

Host Shutoff ◽

Simplex Virus ◽

Herpes Simplex Virus 2 ◽

Endoribonuclease Activity

ABSTRACTWe previously established that cells infected with herpes simplex virus 2 (HSV-2) are disrupted in their ability to form stress granules (SGs) in response to oxidative stress and that this disruption is mediated by virion host shutoff protein (vhs), a virion-associated endoribonuclease. Here, we test the requirement for vhs endoribonuclease activity in disruption of SG formation. We analyzed the ability of HSV-2 vhs carrying the point mutation D215N, which ablates its endoribonuclease activity, to disrupt SG formation in both transfected and infected cells. We present evidence that ablation of vhs endoribonuclease activity results in defects in vhs-mediated disruption of SG formation. Furthermore, we demonstrate that preformed SGs can be disassembled by HSV-2 infection in a manner that requires vhs endoribonuclease activity and that, befitting this ability to promote SG disassembly, vhs is able to localize to SGs. Together these data indicate that endoribonuclease activity must be maintained in order for vhs to disrupt SG formation. We propose a model whereby vhs-mediated destruction of SG mRNA promotes SG disassembly and may also prevent SG assembly.IMPORTANCEStress granules (SGs) are transient cytoplasmic structures that form when a cell is exposed to stress. SGs are emerging as potential barriers to viral infection, necessitating a more thorough understanding of their basic biology. We identified virion host shutoff protein (vhs) as a herpes simplex virus 2 (HSV-2) protein capable of disrupting SG formation. As mRNA is a central component of SGs and the best-characterized activity of vhs is as an endoribonuclease specific for mRNAin vivo, we investigated the requirement for vhs endoribonuclease activity in disruption of SG formation. Our studies demonstrate that endoribonuclease activity is required for vhs to disrupt SG formation and, more specifically, that SG disassembly can be driven by vhs endoribonuclease activity. Notably, during the course of these studies we discovered that there is an ordered departure of SG components during their disassembly and, furthermore, that vhs itself has the capacity to localize to SGs.

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Deletion of the Virion Host Shutoff Protein (vhs) from Herpes Simplex Virus (HSV) Relieves the Viral Block to Dendritic Cell Activation: Potential of vhs− HSV Vectors for Dendritic Cell-Mediated Immunotherapy

Journal of Virology ◽

10.1128/jvi.77.6.3768-3776.2003 ◽

2003 ◽

Vol 77 (6) ◽

pp. 3768-3776 ◽

Cited By ~ 90

Author(s):

Laila Samady ◽

Emanuela Costigliola ◽

Luci MacCormac ◽

Yvonne McGrath ◽

Steve Cleverley ◽

...

Keyword(s):

Herpes Simplex Virus ◽

Herpes Simplex ◽

Dendritic Cell ◽

Cell Activation ◽

Dendritic Cell Activation ◽

Virus Growth ◽

Virion Host Shutoff ◽

Virion Host Shutoff Protein ◽

Host Shutoff ◽

Simplex Virus

ABSTRACT Herpes simplex virus (HSV) infects dendritic cells (DC) efficiently but with minimal replication. HSV, therefore, appears to have evolved the ability to enter DC even though they are nonpermissive for virus growth. This provides a potential utility for HSV in delivering genes to DC for vaccination purposes and also suggests that the life cycle of HSV usually includes the infection of DC. However, DC infected with HSV usually lose the ability to become activated following infection (M. Salio, M. Cella, M. Suter, and A. Lanzavecchia, Eur. J. Immunol. 29:3245-3253, 1999; M. Kruse, O. Rosorius, F. Kratzer, G. Stelz, C. Kuhnt, G. Schuler, J. Hauber, and A. Steinkasserer, J. Virol. 74:7127-7136, 2000). We report that for DC to retain the ability to become activated following HSV infection, the virion host shutoff protein (vhs) must be deleted. vhs usually functions to destabilize mRNA in favor of the production of HSV proteins in permissive cells. We have found that it also plays a key role in the inactivation of DC and is therefore likely to be important for immune evasion by the virus. Here, vhs would be anticipated to prevent DC activation in the early stages of infection of an individual with HSV, reducing the induction of cellular immune responses and thus preventing virus clearance during repeated cycles of virus latency and reactivation. Based on this information, replication-incompetent HSV vectors with vhs deleted which allow activation of DC and the induction of specific T-cell responses to delivered antigens have been constructed. These responses are greater than if DC are loaded with antigen by incubation with recombinant protein.

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Evidence for Translational Regulation by the Herpes Simplex Virus Virion Host Shutoff Protein

Journal of Virology ◽

10.1128/jvi.01819-09 ◽

2010 ◽

Vol 84 (12) ◽

pp. 6041-6049 ◽

Cited By ~ 31

Author(s):

Holly A. Saffran ◽

G. Sullivan Read ◽

James R. Smiley

Keyword(s):

Gene Expression ◽

Herpes Simplex Virus ◽

Herpes Simplex ◽

Mutational Analysis ◽

Vero Cells ◽

Viral Mrnas ◽

Virion Host Shutoff ◽

Virion Host Shutoff Protein ◽

Host Shutoff ◽

Simplex Virus

ABSTRACT The herpes simplex virus (HSV) virion host shutoff protein (vhs) encoded by gene UL41 is an mRNA-specific RNase that triggers accelerated degradation of host and viral mRNAs in infected cells. We report here that vhs is also able to modulate reporter gene expression without greatly altering the levels of the target mRNA in transient-transfection assays conducted in HeLa cells. We monitored the effects of vhs on a panel of bicistronic reporter constructs bearing a variety of internal ribosome entry sites (IRESs) located between two test cistrons. As expected, vhs inhibited the expression of the 5′ cistrons of all of these constructs; however, the response of the 3′ cistron varied with the IRES: expression driven from the wild-type EMCV IRES was strongly suppressed, while expression controlled by a mutant EMCV IRES and the cellular ApaF1, BiP, and DAP5 IRES elements was strongly activated. In addition, several HSV type 1 (HSV-1) 5′ untranslated region (5′ UTR) sequences also served as positive vhs response elements in this assay. IRES activation was also observed in 293 and HepG2 cells, but no such response was observed in Vero cells. Mutational analysis has yet to uncouple the ability of vhs to activate 3′ cistron expression from its shutoff activity. Remarkably, repression of 5′ cistron expression could be observed under conditions where the levels of the reporter RNA were not correspondingly reduced. These data provide strong evidence that vhs can modulate gene expression at the level of translation and that it is able to activate cap-independent translation through specific cis-acting elements.

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