scholarly journals Small Interfering RNAs That Deplete the Cellular Translation Factor eIF4H Impede mRNA Degradation by the Virion Host Shutoff Protein of Herpes Simplex Virus

2008 ◽  
Vol 82 (13) ◽  
pp. 6600-6609 ◽  
Author(s):  
Nandini Sarma ◽  
Deepali Agarwal ◽  
Lora A. Shiflett ◽  
G. Sullivan Read
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Translation Initiation ◽  
Mrna Levels ◽  
Small Interfering Rnas ◽  
Virion Host Shutoff ◽  
Infected Cells ◽  
Actin Mrna ◽  
Host Shutoff ◽  
Simplex Virus

ABSTRACT The herpes simplex virus (HSV) virion host shutoff (Vhs) protein is an endoribonuclease that accelerates decay of many host and viral mRNAs. Purified Vhs does not distinguish mRNAs from nonmessenger RNAs and cuts target RNAs at many sites, yet within infected cells it is targeted to mRNAs and cleaves those mRNAs at preferred sites including, for some, regions of translation initiation. This targeting may result in part from Vhs binding to the translation initiation factor eIF4H; in particular, several mutations in Vhs that abrogate its binding to eIF4H also abolish its mRNA-degradative activity, even though the mutant proteins retain endonuclease activity. To further investigate the role of eIF4H in Vhs activity, HeLa cells were depleted of eIF4H or other proteins by transfection with small interfering RNAs (siRNAs) 48 h prior to infection or mock infection in the presence of actinomycin D. Cellular mRNA levels were then assayed 5 h after infection. In cells transfected with an siRNA for the housekeeping enzyme glyceraldehyde-3-phosphate dehydrogenase, wild-type HSV infection reduced β-actin mRNA levels to between 20 and 30% of those in mock-infected cells, indicative of a normal Vhs activity. In contrast, in cells transfected with any of three eIF4H siRNAs, β-actin mRNA levels were indistinguishable in infected and mock-infected cells, suggesting that eIF4H depletion impeded Vhs-mediated degradation. Depletion of the related factor eIF4B did not affect Vhs activity. The data suggest that eIF4H binding is required for Vhs-induced degradation of many mRNAs, perhaps by targeting Vhs to mRNAs and to preferred sites within mRNAs.

scholarly journals mRNA Decay during Herpes Simplex Virus (HSV) Infections: Protein-Protein Interactions Involving the HSV Virion Host Shutoff Protein and Translation Factors eIF4H and eIF4A

2005 ◽  
Vol 79 (15) ◽  
pp. 9651-9664 ◽  
Author(s):  
Pinghui Feng ◽  
David N. Everly ◽  
G. Sullivan Read
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Translation Initiation ◽  
Mammalian Cells ◽  
Translation Initiation Factor ◽  
Site Directed Mutagenesis ◽  
Initiation Factor ◽  
Virion Host Shutoff ◽  
Host Shutoff ◽  
Simplex Virus

ABSTRACT During lytic infections, the virion host shutoff (Vhs) protein of herpes simplex virus accelerates the degradation of both host and viral mRNAs. In so doing, it helps redirect the cell from host to viral protein synthesis and facilitates the sequential expression of different viral genes. Vhs interacts with the cellular translation initiation factor eIF4H, and several point mutations that abolish its mRNA degradative activity also abrogate its ability to bind eIF4H. In addition, a complex containing bacterially expressed Vhs and a glutathione S-transferase (GST)-eIF4H fusion protein has RNase activity. eIF4H shares a region of sequence homology with eIF4B, and it appears to be functionally similar in that both stimulate the RNA helicase activity of eIF4A, a component of the mRNA cap-binding complex eIF4F. We show that eIF4H interacts physically with eIF4A in the yeast two-hybrid system and in GST pull-down assays and that the two proteins can be coimmunoprecipitated from mammalian cells. Vhs also interacts with eIF4A in GST pull-down and coimmunoprecipitation assays. Site-directed mutagenesis of Vhs and eIF4H revealed residues of each that are important for their mutual interaction, but not for their interaction with eIF4A. Thus, Vhs, eIF4H, and eIF4A comprise a group of proteins, each of which is able to interact directly with the other two. Whether they interact simultaneously as a tripartite complex or sequentially is unclear. The data suggest a mechanism for linking the degradation of an mRNA to its translation and for targeting Vhs to mRNAs and to regions of translation initiation.

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 The Virion Host Shutoff Endonuclease (UL41) of Herpes Simplex Virus Interacts with the Cellular Cap-Binding Complex eIF4F

2010 ◽  
Vol 84 (13) ◽  
pp. 6886-6890 ◽  
Author(s):  
Heidi G. Page ◽  
G. Sullivan Read
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Translation Initiation ◽  
Viral Mrnas ◽  
Translation Factors ◽  
Virion Host Shutoff ◽  
Cap Binding Complex ◽  
Host Shutoff ◽  
Simplex Virus

ABSTRACT The herpes simplex virus Vhs endonuclease degrades host and viral mRNAs. Isolated Vhs cuts any RNA at many sites. Yet, within cells, it targets mRNAs and cuts at preferred sites, including regions of translation initiation. Previous studies have shown that Vhs binds the translation factors eIF4A and eIF4H. Here, we show that Vhs binds the cap-binding complex eIF4F. Association with eIF4F correlated with the ability of Vhs to bind eIF4A but not eIF4H. All Vhs proteins that degrade mRNAs associated with eIF4F. However, simply tethering an active endonuclease to eIF4F is not sufficient to degrade mRNAs. Binding to eIF4H may also be required.

scholarly journals Herpes simplex virus 1 expressing GFP-tagged virion host shutoff (vhs) protein uncouples the activities of degradation and nuclear retention of the infected cell transcriptome

2022 ◽  
Author(s):  
Emma Louise Wise ◽  
Jerzy Samolej ◽  
Gillian Elliott
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Infected Cell ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Retention ◽  
Virion Host Shutoff ◽  
Infected Cells ◽  
Host Shutoff ◽  
Cell Transcriptome ◽  
Simplex Virus

Virion host shutoff (vhs) protein is an endoribonuclease encoded by herpes simplex virus 1 (HSV1). Vhs causes a number of changes to the infected cell environment that favour translation of late (L) virus proteins: cellular mRNAs are degraded, immediate-early (IE) and early (E) viral transcripts are sequestered in the nucleus with polyA binding protein (PABPC1), and dsRNA is degraded to help dampen the PKR-dependent stress response. To further our understanding of the cell biology of vhs, we constructed a virus expressing vhs tagged at its C-terminus with GFP. When first expressed, vhs-GFP localised to juxtanuclear clusters, and later it colocalised and interacted with its binding partner VP16, and was packaged into virions. Despite vhs-GFP maintaining activity when expressed in isolation, it failed to degrade mRNA or relocalise PABPC1 during infection, while viral transcript levels were similar to those seen for a vhs knockout virus. PKR phosphorylation was also enhanced in vhs-GFP infected cells, in line with a failure to degrade dsRNA. Nonetheless, mRNA FISH revealed that as in Wt but not Dvhs infection, IE and E, but not L transcripts were retained in the nucleus of vhs-GFP infected cells at late times. Moreover, a representative cellular transcript which is ordinarily highly susceptible to vhs degradation, was also retained in the nucleus. These results reveal that the vhs-induced nuclear retention of the infected cell transcriptome is dependent on vhs expression but not on its endoribonuclease activity, uncoupling these two functions of vhs.

scholarly journals The Splicing History of an mRNA Affects Its Level of Translation and Sensitivity to Cleavage by the Virion Host Shutoff Endonuclease during Herpes Simplex Virus Infections

2016 ◽  
Vol 90 (23) ◽  
pp. 10844-10856 ◽  
Author(s):  
Jouliana Sadek ◽  
G. Sullivan Read
Keyword(s):  
Gene Expression ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Mrna Splicing ◽  
Exon Junction ◽  
Virion Host Shutoff ◽  
History Of ◽  
Host Shutoff ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACTDuring lytic herpes simplex virus (HSV) infections, the virion host shutoff (Vhs) (UL41) endoribonuclease degrades many cellular and viral mRNAs. In uninfected cells, spliced mRNAs emerge into the cytoplasm bound by exon junction complexes (EJCs) and are translated several times more efficiently than unspliced mRNAs that have the same sequence but lack EJCs. Notably, most cellular mRNAs are spliced, whereas most HSV mRNAs are not. To examine the effect of splicing on gene expression during HSV infection, cells were transfected with plasmids harboring an unspliced renilla luciferase (RLuc) reporter mRNA or RLuc constructs with introns near the 5′ or 3′ end of the gene. After splicing of intron-containing transcripts, all three RLuc mRNAs had the same primary sequence. Upon infection in the presence of actinomycin D, spliced mRNAs were much less sensitive to degradation by copies of Vhs from infecting virions than were unspliced mRNAs. During productive infections (in the absence of drugs), RLuc was expressed at substantially higher levels from spliced than from unspliced mRNAs. Interestingly, the stimulatory effect of splicing on RLuc expression was significantly greater in infected than in uninfected cells. The translational stimulatory effect of an intron during HSV-1 infections could be replicated by artificially tethering various EJC components to an unspliced RLuc transcript. Thus, the splicing history of an mRNA, and the consequent presence or absence of EJCs, affects its level of translation and sensitivity to Vhs cleavage during lytic HSV infections.IMPORTANCEMost mammalian mRNAs are spliced. In contrast, of the more than 80 mRNAs harbored by herpes simplex virus 1 (HSV-1), only 5 are spliced. In addition, synthesis of the immediate early protein ICP27 causes partial inhibition of pre-mRNA splicing, with the resultant accumulation of both spliced and unspliced versions of some mRNAs in the cytoplasm. A common perception is that HSV-1 infection necessarily inhibits the expression of spliced mRNAs. In contrast, this study demonstrates two instances in which pre-mRNA splicing actually enhances the synthesis of proteins from mRNAs during HSV-1 infections. Specifically, splicing stabilized an mRNA against degradation by copies of the Vhs endoribonuclease from infecting virions and greatly enhanced the amount of protein synthesized from spliced mRNAs at late times after infection. The data suggest that splicing, and the resultant presence of exon junction complexes on an mRNA, may play an important role in gene expression during HSV-1 infections.

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 Packaging of the Virion Host Shutoff (Vhs) Protein of Herpes Simplex Virus: Two Forms of the Vhs Polypeptide Are Associated with Intranuclear B and C Capsids, but Only One Is Associated with Enveloped Virions

2007 ◽  
Vol 81 (3) ◽  
pp. 1148-1161 ◽  
Author(s):  
G. Sullivan Read ◽  
Mary Patterson
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Viral Envelope ◽  
Translation Product ◽  
Primary Translation Product ◽  
Virion Host Shutoff ◽  
Host Shutoff ◽  
Simplex Virus

ABSTRACT The virion host shutoff (Vhs) protein (UL41) is a minor component of herpes simplex virus virions which, following penetration, accelerates turnover of host and viral mRNAs. Infected cells contain 58-kDa and 59.5-kDa forms of Vhs, which differ in the extent of phosphorylation, yet only a 58-kDa polypeptide is incorporated into virions. In pulse-chase experiments, the primary Vhs translation product comigrated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis with the 58-kDa virion polypeptide, and could be chased to 59.5 kDa. While both 59.5-kDa and 58-kDa forms were found in nuclear and cytoplasmic fractions, the 59.5-kDa form was significantly enriched in the nucleus. Both forms were associated with intranuclear B and C capsids, yet only the 58-kDa polypeptide was found in enveloped cytoplasmic virions. A 58-kDa form, but not the 59.5-kDa form, was found in L particles, noninfectious particles that contain an envelope and tegument but no capsid. The data suggest that virions contain two populations of Vhs that are packaged by different pathways. In the first pathway, the primary translation product is processed to 59.5 kDa, is transported to the nucleus, binds intranuclear capsids, and is converted to 58 kDa at some stage prior to final envelopment. The second pathway does not involve the 59.5-kDa form or interactions between Vhs and capsids. Instead, the primary translation product is phosphorylated to the 58-kDa virion form and packaged through interactions with other tegument proteins in the cytoplasm or viral envelope proteins at the site of final envelopment.

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
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