scholarly journals Herpes Simplex Virus Virion Host Shutoff Protein Requires a Mammalian Factor for Efficient In Vitro Endoribonuclease Activity

2001 ◽  
Vol 75 (3) ◽  
pp. 1172-1185 ◽  
Author(s):  
Patricia Lu ◽  
Frank E. Jones ◽  
Holly A. Saffran ◽  
James R. Smiley
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
In Vitro Translation ◽  
Mrna Turnover ◽  
Virion Host Shutoff ◽  
Virion Host Shutoff Protein ◽  
Host Shutoff ◽  
Simplex Virus ◽  
Endoribonuclease Activity

ABSTRACT The virion host shutoff protein (vhs) of herpes simplex virus (HSV) triggers global shutoff of host protein synthesis and accelerated mRNA turnover during virus infection and induces endoribonucleolytic cleavage of exogenous RNA substrates when it is produced in a rabbit reticulocyte (RRL) in vitro translation system. Although vhs induces RNA turnover in the absence of other HSV gene products, it is not yet known whether cellular factors are required for its activity. As one approach to addressing this question, we expressed vhs in the budding yeast Saccharomyces cerevisiae. Expression of vhs inhibited colony formation, and the severity of this effect varied with the carbon source. The biological relevance of this effect was assessed by examining the activity of five mutant forms of vhs bearing previously characterized in-frame linker insertions. The results indicated a complete concordance between the growth inhibition phenotype in yeast and mammalian host cell shutoff. Despite these results, expression of vhs did not trigger global mRNA turnover in vivo, and cell extracts of yeast expressing vhs displayed little if any vhs-dependent endoribonuclease activity. However, activity was readily detected when such extracts were mixed with RRL. These data suggest that the vhs-dependent endoribonuclease requires one or more mammalian macromolecular factors for efficient activity.

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

2016 ◽  
Vol 90 (17) ◽  
pp. 7943-7955 ◽  
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.

scholarly journals Herpes Simplex Virus 1 Counteracts Viperin via Its Virion Host Shutoff Protein UL41

2014 ◽  
Vol 88 (20) ◽  
pp. 12163-12166 ◽  
Author(s):  
G. Shen ◽  
K. Wang ◽  
S. Wang ◽  
M. Cai ◽  
M.-l. Li ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Herpes Simplex Virus 1 ◽  
Virion Host Shutoff ◽  
Virion Host Shutoff Protein ◽  
Host Shutoff ◽  
Simplex Virus

scholarly journals A Single Amino Acid Substitution in Herpes Simplex Virus Type 1 VP16 Inhibits Binding to the Virion Host Shutoff Protein and Is Incompatible with Virus Growth

2003 ◽  
Vol 77 (5) ◽  
pp. 2892-2902 ◽  
Author(s):  
J. Knez ◽  
P. T. Bilan ◽  
J. P. Capone
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Immediate Early ◽  
Virus Growth ◽  
Amino Terminal ◽  
Virion Host Shutoff ◽  
Virion Host Shutoff Protein ◽  
Simplex Virus

ABSTRACT In addition to its well-established role in the activation of herpes simplex virus immediate-early gene transcription, VP16 interacts with and downregulates the function of the virion host shutoff protein (vhs), thereby attenuating vhs-mediated destruction of viral mRNAs and translational arrest at late times of infection. We have carried out two-hybrid analysis in vivo and protein-protein interaction assays in vitro to identify determinants in VP16 necessary for interaction with vhs. The minimal amino-terminal subfragment of VP16 capable of binding to vhs encompassed residues 1 to 345. Alteration of a single leucine at position 344 to alanine (L344A) in the context of the amino-terminal fragment of VP16 containing residues 1 to 404 was sufficient to abolish interaction with vhs in vitro and in vivo. Leu344 could be replaced with hydrophobic amino acids (Ile, Phe, Met, or Val) but not by Asn, Lys, or Pro, indicating that hydrophobicity is an important property of binding to vhs. VP16 harboring a loss-of-function mutation at L344 was not compromised in its ability to interact with host cell factor (HCF-1) or to activate transcription of viral immediate-early genes in transient-transfection assays. Virus complementation assays using the VP16-null virus 8MA and the VP16/vhs double-mutant virus 8MAΔSma showed that VP16(L344A) was able to complement the growth of 8MAΔSma but not 8MA. Thus, a single point mutation in VP16 uncouples binding to vhs from other functions of VP16 required for virus growth and indicates that direct physical association between VP16 and vhs is necessary to sustain a productive infection.

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

1994 ◽  
Vol 68 (4) ◽  
pp. 2339-2346 ◽  
Author(s):  
C A Smibert ◽  
B Popova ◽  
P Xiao ◽  
J P Capone ◽  
J R Smiley
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virion Host Shutoff ◽  
Virion Host Shutoff Protein ◽  
Host Shutoff ◽  
Simplex Virus

scholarly journals Herpes Simplex Virus Virion Host Shutoff Protein Is Stimulated by Translation Initiation Factors eIF4B and eIF4H

2004 ◽  
Vol 78 (9) ◽  
pp. 4684-4699 ◽  
Author(s):  
Rosalyn C. Doepker ◽  
Wei-Li Hsu ◽  
Holly A. Saffran ◽  
James R. Smiley
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Translation Initiation ◽  
Encephalomyocarditis Virus ◽  
Translation Initiation Factor ◽  
Rnase Activity ◽  
Virion Host Shutoff ◽  
Virion Host Shutoff Protein ◽  
Host Shutoff ◽  
Simplex Virus

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.

scholarly journals 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

2003 ◽  
Vol 77 (6) ◽  
pp. 3768-3776 ◽  
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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