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Hennig T, Djakovic L, Dölken L, Whisnant AW. A Review of the Multipronged Attack of Herpes Simplex Virus 1 on the Host Transcriptional Machinery. Viruses 2021; 13:1836. [PMID: 34578417 PMCID: PMC8473234 DOI: 10.3390/v13091836] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/08/2021] [Accepted: 09/10/2021] [Indexed: 12/31/2022] Open
Abstract
During lytic infection, herpes simplex virus (HSV) 1 induces a rapid shutoff of host RNA synthesis while redirecting transcriptional machinery to viral genes. In addition to being a major human pathogen, there is burgeoning clinical interest in HSV as a vector in gene delivery and oncolytic therapies, necessitating research into transcriptional control. This review summarizes the array of impacts that HSV has on RNA Polymerase (Pol) II, which transcribes all mRNA in infected cells. We discuss alterations in Pol II holoenzymes, post-translational modifications, and how viral proteins regulate specific activities such as promoter-proximal pausing, splicing, histone repositioning, and termination with respect to host genes. Recent technological innovations that have reshaped our understanding of previous observations are summarized in detail, along with specific research directions and technical considerations for future studies.
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Affiliation(s)
- Thomas Hennig
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, 97078 Würzburg, Germany; (T.H.); (L.D.)
| | - Lara Djakovic
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, 97078 Würzburg, Germany; (T.H.); (L.D.)
| | - Lars Dölken
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, 97078 Würzburg, Germany; (T.H.); (L.D.)
- Helmholtz Center for Infection Research (HZI), Helmholtz Institute for RNA-Based Infection Research (HIRI), 97080 Würzburg, Germany
| | - Adam W. Whisnant
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, 97078 Würzburg, Germany; (T.H.); (L.D.)
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2
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Boudreault S, Roy P, Lemay G, Bisaillon M. Viral modulation of cellular RNA alternative splicing: A new key player in virus-host interactions? WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1543. [PMID: 31034770 PMCID: PMC6767064 DOI: 10.1002/wrna.1543] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/25/2019] [Accepted: 04/08/2019] [Indexed: 12/26/2022]
Abstract
Upon viral infection, a tug of war is triggered between host cells and viruses to maintain/gain control of vital cellular functions, the result of which will ultimately dictate the fate of the host cell. Among these essential cellular functions, alternative splicing (AS) is an important RNA maturation step that allows exons, or parts of exons, and introns to be retained in mature transcripts, thereby expanding proteome diversity and function. AS is widespread in higher eukaryotes, as it is estimated that nearly all genes in humans are alternatively spliced. Recent evidence has shown that upon infection by numerous viruses, the AS landscape of host‐cells is affected. In this review, we summarize recent advances in our understanding of how virus infection impacts the AS of cellular transcripts. We also present various molecular mechanisms allowing viruses to modulate cellular AS. Finally, the functional consequences of these changes in the RNA splicing signatures during virus–host interactions are discussed. This article is categorized under:RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing
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Affiliation(s)
- Simon Boudreault
- Département de biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Patricia Roy
- Département de biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Guy Lemay
- Département de microbiologie, infectiologie et immunologie, Faculté de médecine, Université de Montréal, Montréal, Québec, Canada
| | - Martin Bisaillon
- Département de biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
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3
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mRNA decay during herpes simplex virus (HSV) infections: mutations that affect translation of an mRNA influence the sites at which it is cleaved by the HSV virion host shutoff (Vhs) protein. J Virol 2012; 87:94-109. [PMID: 23077305 DOI: 10.1128/jvi.01557-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During lytic infections, the herpes simplex virus (HSV) virion host shutoff (Vhs) endoribonuclease degrades many host and viral mRNAs. Within infected cells it cuts mRNAs at preferred sites, including some in regions of translation initiation. Vhs binds the translation initiation factors eIF4H, eIF4AI, and eIF4AII, suggesting that its mRNA degradative function is somehow linked to translation. To explore how Vhs is targeted to preferred sites, we examined the in vitro degradation of a target mRNA in rabbit reticulocyte lysates containing in vitro-translated Vhs. Vhs caused rapid degradation of mRNAs beginning with cleavages at sites in the first 250 nucleotides, including a number near the start codon and in the 5' untranslated region. Ligation of the ends to form a circular mRNA inhibited Vhs cleavage at the same sites at which it cuts capped linear molecules. This was not due to an inability to cut any circular RNA, since Vhs cuts circular mRNAs containing an encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) at the same sites as linear molecules with the IRES. Cutting linear mRNAs at preferred sites was augmented by the presence of a 5' cap. Moreover, mutations that altered the 5' proximal AUG abolished Vhs cleavage at nearby sites, while mutations that changed sequences surrounding the AUG to improve their match to the Kozak consensus sequence enhanced Vhs cutting near the start codon. The results indicate that mutations in an mRNA that affect its translation affect the sites at which it is cut by Vhs and suggest that Vhs is directed to its preferred cut sites during translation initiation.
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Li M, Wang S, Cai M, Guo H, Zheng C. Characterization of molecular determinants for nucleocytoplasmic shuttling of PRV UL54. Virology 2011; 417:385-93. [PMID: 21777931 DOI: 10.1016/j.virol.2011.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 06/02/2011] [Accepted: 06/06/2011] [Indexed: 10/17/2022]
Abstract
The pseudorabies virus (PRV) early protein UL54 is a homologue of the herpes simplex virus 1 (HSV-1) immediate-early protein ICP27, which is a multifunctional protein and essential for HSV-1 infection. To determine if UL54 might shuttle between the nucleus and cytoplasm, as has been shown for its homologues in human herpesviruses, the molecular determinants for its nucleocytoplasmic shuttling were investigated. Heterokaryon assays demonstrated that UL54 was a nucleocytoplasmic shuttling protein and this property could not be blocked by leptomycin B, an inhibitor of chromosome region maintenance 1 (CRM1). However, TAP/NXF1 promoted the nuclear export of UL54 and interacted with UL54, suggesting that UL54 shuttles between the nucleus and the cytoplasm via a TAP/NXF1, but not CRM1, dependent nuclear export pathway. Furthermore, UL54 was demonstrated to target to the nucleus through a classic Ran-, importin β1- and α5-dependent nuclear import mechanism.
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Affiliation(s)
- Meili Li
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
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5
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Ding Q, Guo H, Lin F, Pan W, Ye B, Zheng AC. Characterization of the nuclear import and export mechanisms of bovine herpesvirus-1 infected cell protein 27. Virus Res 2010; 149:95-103. [PMID: 20109505 DOI: 10.1016/j.virusres.2010.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Accepted: 01/19/2010] [Indexed: 11/16/2022]
Abstract
In previous study, we have identified a nuclear localization signal (NLS) and a nucleolar localization signal (NoLS) in bovine herpesvirus-1 (BHV-1) infected cell protein 27 (BICP27), which targets predominantly to the nucleolus. Furthermore, the C-terminal 300 amino acid residues targets exclusively to the cytoplasm, suggesting that BICP27 might contain a nuclear export signal (NES). Amino acid sequence analysis revealed that there is a cluster of leucine-rich residues resembling a NES. Heterokaryon assays demonstrated that BICP27 is capable of shuttling between the nucleus and the cytoplasm of the BHV-1 infected, BICP27 and BICP27-EYFP transfected cells. Deletion mutant analysis revealed that this property is attributed to the leucine-rich NES 299LEELCAARRLSL310. Moreover, the functional NES could mediate transport of a monomer EYFP and a dimer EYFP to the cytoplasm. The nucleocytoplasmic shuttling of BICP27 and the nuclear export of NES-EYFP and NES-dEYFP could be blocked by leptomycin LMB, an inhibitor of the chromosomal region maintenance 1 (CRM1), which is the receptor for exportin-1-dependent nuclear export. In addition, the nuclear import of BICP27 was inhibited by a dominant negative Ran-GTP, namely Ran-GTP Q69L, indicating that BICP27 localized to the nucleus by means of a classic Ran dependent nuclear import mechanism. In conclusion, these results demonstrate that BICP27 shuttles between the nucleus and the cytoplasm by the functional NES and NLS through a CRM1-dependent nuclear export pathway and a Ran dependent nuclear import pathway.
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Affiliation(s)
- Qiong Ding
- State Key Laboratory of Virology, Molecular Virology and Viral Immunology Research Group, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071, PR China
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6
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Guo H, Ding Q, Lin F, Pan W, Lin J, Zheng AC. Characterization of the nuclear and nucleolar localization signals of bovine herpesvirus-1 infected cell protein 27. Virus Res 2009; 145:312-20. [PMID: 19682510 PMCID: PMC7125963 DOI: 10.1016/j.virusres.2009.07.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2009] [Revised: 07/31/2009] [Accepted: 07/31/2009] [Indexed: 11/19/2022]
Abstract
Bovine herpesvirus-1 infected cell protein 27 (BICP27) was detected predominantly in the nucleolus. The open reading frame of BICP27 was fused with the enhanced yellow fluorescent protein (EYFP) gene to investigate its subcellular localization in live cells and BICP27 was able to direct monomeric, dimeric or trimeric EYFP exclusively to the nucleolus. By constructing a series of deletion mutants, the putative nuclear localization signal (NLS) and nucleolar localization signal (NoLS) were mapped to (81)RRAR(84) and (86)RPRRPRRRPRRR(97) respectively. Specific deletion of the putative NLS, NoLS or both abrogated nuclear localization, nucleolar localization or both respectively. Furthermore, NLS was able to direct trimeric EYFP predominantly to the nucleus but excluded from the nucleolus, whereas NoLS targeted trimeric EYFP primarily to the nucleus, and enriched in the nucleolus with faint staining in the cytoplasm. NLS+NoLS directed trimeric EYFP predominantly to the nucleolus with faint staining in the nucleus. Moreover, deletion of NLS+NoLS abolished the transactivating activity of BICP27 on gC promoter, whereas deletion of either NLS or NoLS did not. The study demonstrated that BICP27 is a nucleolar protein, adding BICP27 to the growing list of transactivators which localize to the nucleolus.
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Affiliation(s)
- Hong Guo
- State Key Laboratory of Virology, Molecular Virology and Viral Immunology Research Group, Wuhan Institute of Virology, Chinese Academy of Sciences, 44 Xiaohongshan, Wuchang, Wuhan, Hubei 430071, PR China
| | - Qiong Ding
- State Key Laboratory of Virology, Molecular Virology and Viral Immunology Research Group, Wuhan Institute of Virology, Chinese Academy of Sciences, 44 Xiaohongshan, Wuchang, Wuhan, Hubei 430071, PR China
| | - Fusen Lin
- State Key Laboratory of Virology, Molecular Virology and Viral Immunology Research Group, Wuhan Institute of Virology, Chinese Academy of Sciences, 44 Xiaohongshan, Wuchang, Wuhan, Hubei 430071, PR China
| | - Weiwei Pan
- State Key Laboratory of Virology, Molecular Virology and Viral Immunology Research Group, Wuhan Institute of Virology, Chinese Academy of Sciences, 44 Xiaohongshan, Wuchang, Wuhan, Hubei 430071, PR China
| | - Jianyin Lin
- Department of Molecular Medicine, Fujian Medical University, 88 Jiaotong Road, Fuzhou, Fujian 350001, PR China
| | - Alan C. Zheng
- State Key Laboratory of Virology, Molecular Virology and Viral Immunology Research Group, Wuhan Institute of Virology, Chinese Academy of Sciences, 44 Xiaohongshan, Wuchang, Wuhan, Hubei 430071, PR China
- Corresponding author. Tel.: +86 27 8719 8676; fax: +86 27 8719 8676.
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Iacovides DC, O'Shea CC, Oses-Prieto J, Burlingame A, McCormick F. Critical role for arginine methylation in adenovirus-infected cells. J Virol 2007; 81:13209-17. [PMID: 17686851 PMCID: PMC2169124 DOI: 10.1128/jvi.01415-06] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
During the late stages of adenovirus infection, the 100K protein (100K) inhibits the translation of cellular messages in the cytoplasm and regulates hexon trimerization and assembly in the nucleus. However, it is not known how it switches between these two functions. Here we show that 100K is methylated on arginine residues at its C terminus during infection and that this region is necessary for binding PRMT1 methylase. Methylated 100K is exclusively nuclear. Mutation of the third RGG motif (amino acids 741 to 743) prevents localization to the nucleus during infection, suggesting that methylation of that sequence is important for 100K shuttling. Treatment of infected cells with methylation inhibitors inhibits expression of late structural proteins. These data suggest that arginine methylation of 100K is necessary for its localization to the nucleus and is a critical cellular function necessary for productive adenovirus infection.
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Han Z, Swaminathan S. Kaposi's sarcoma-associated herpesvirus lytic gene ORF57 is essential for infectious virion production. J Virol 2007; 80:5251-60. [PMID: 16699005 PMCID: PMC1472138 DOI: 10.1128/jvi.02570-05] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ORF57 gene of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a nuclear protein expressed during the lytic phase of KSHV replication. An ORF57 homolog is present in all known human herpesviruses and many animal herpesviruses. Many of these proteins have been demonstrated to have essential transcriptional and posttranscriptional regulatory functions. ORF57 enhances expression of reporter genes posttranscriptionally in vitro and may synergize with transcription factors to enhance gene transcription. However, the biologic role of ORF57 in KSHV replication has not been established. In this study, we demonstrate that ORF57 is essential for productive KSHV lytic replication by constructing a recombinant KSHV in which ORF57 expression has been specifically inactivated. The ORF57-null KSHV recombinant was unable to produce virion progeny or fully express several other lytic KSHV genes except when ORF57 was provided in trans. The Epstein-Barr virus (EBV) homolog of ORF57, SM, was unable to rescue lytic KSHV virion production, although EBV SM does enhance KSHV lytic gene expression from the ORF57-null mutant. Conversely, ORF57 did not rescue an SM-null recombinant EBV, indicating the existence of virus-specific functions for the ORF57 family of genes.
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Affiliation(s)
- Zhao Han
- Program in Cancer Genetics, Epigenetics and Tumor Virology, UF Shands Cancer Center, Box 100232, University of Florida, Gainesville, FL 32610-0232, USA
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9
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Abstract
Serotypical application of herpes simplex virus (HSV) vectors to gene therapy (type 1) and prophylactic vaccines (types 1 and 2) has garnered substantial clinical interest recently. HSV vectors and amplicons have also been employed as helper virus constructs for manufacture of the dependovirus adeno-associated virus (AAV). Large quantities of infectious HSV stocks are requisite for these therapeutic applications, requiring a scalable vector manufacturing and processing platform comprised of unit operations which accommodate the fragility of HSV. In this study, production of a replication deficient rHSV-1 vector bearing the rep and cap genes of AAV-2 (denoted rHSV-rep2/cap2) was investigated. Adaptation of rHSV production from T225 flasks to a packed bed, fed-batch bioreactor permitted an 1100-fold increment in total vector production without a decrease in specific vector yield (pfu/cell). The fed-batch bioreactor system afforded a rHSV-rep2/cap2 vector recovery of 2.8 x 10(12) pfu. The recovered vector was concentrated by tangential flow filtration (TFF), permitting vector stocks to be formulated at greater than 1.5 x 10(9) pfu/mL.
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Affiliation(s)
- David R Knop
- Applied Genetic Technologies Corporation (AGTC), Alachua, Florida 32615, USA.
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10
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Malik P, Schirmer EC. The Kaposi's sarcoma-associated herpesvirus ORF57 protein: a pleurotropic regulator of gene expression. Biochem Soc Trans 2006; 34:705-10. [PMID: 17052179 DOI: 10.1042/bst0340705] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Herpesviridae comprises over 120 viruses infecting a wide range of vertebrates including humans and livestock. Herpesvirus infections typically produce dermal lesions or immune cell destruction, but can also lead to oncogenesis, especially with KSHV (Kaposi's sarcoma-associated herpesvirus). All herpesviruses are nuclear replicating viruses that subvert cellular processes such as nucleocytoplasmic transport for their advantage. For virus replication to take over the cell and produce lytic infection requires that virus gene expression outpace that of the host cell. KSHV ORF57 (open reading frame 57) appears to play a major role in this by (i) serving as a nuclear export receptor to carry intronless viral mRNAs out of the nucleus and (ii) inhibiting expression of intron-containing host mRNAs. As most of the virally encoded mRNAs are intronless compared with host cell mRNAs, these two mechanisms are critical to overcoming host gene expression.
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Affiliation(s)
- P Malik
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of Edinburgh, Kings Buildings, Mayfield Road, Edinburgh EH9 3JR, UK.
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11
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Dai-Ju JQ, Li L, Johnson LA, Sandri-Goldin RM. ICP27 interacts with the C-terminal domain of RNA polymerase II and facilitates its recruitment to herpes simplex virus 1 transcription sites, where it undergoes proteasomal degradation during infection. J Virol 2006; 80:3567-81. [PMID: 16537625 PMCID: PMC1440381 DOI: 10.1128/jvi.80.7.3567-3581.2006] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) ICP27 has been shown to interact with RNA polymerase II (RNAP II) holoenzyme. Here, we show that ICP27 interacts with the C-terminal domain (CTD) of RNAP II and that ICP27 mutants that cannot interact fail to relocalize RNAP II to viral transcription sites, suggesting a role for ICP27 in RNAP II recruitment. Using monoclonal antibodies specific for different phosphorylated forms of the RNAP II CTD, we found that the serine-2 phosphorylated form, which is found predominantly in elongating complexes, was not recruited to viral transcription sites. Further, there was an overall reduction in phosphoserine-2 staining. Western blot analysis revealed that there was a pronounced decrease in the phosphoserine-2 form and in overall RNAP II levels in lysates from cells infected with wild-type HSV-1. There was no appreciable difference in cdk9 levels, suggesting that protein degradation rather than dephosphorylation was occurring. Treatment of infected cells with proteasome inhibitors MG-132 and lactacystin prevented the decrease in the phosphoserine-2 form and in overall RNAP II levels; however, there was a concomitant decrease in the levels of several HSV-1 late proteins and in virus yield. Proteasomal degradation has been shown to resolve stalled RNAP II complexes at sites of DNA damage to allow 3' processing of transcripts. Thus, we propose that at later times of infection when robust transcription and DNA replication are occurring, elongating complexes may collide and proteasomal degradation may be required for resolution.
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Affiliation(s)
- Jenny Q Dai-Ju
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California at Irvine, Irvine, CA 92697-4025, USA
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Chen IHB, Li L, Silva L, Sandri-Goldin RM. ICP27 recruits Aly/REF but not TAP/NXF1 to herpes simplex virus type 1 transcription sites although TAP/NXF1 is required for ICP27 export. J Virol 2005; 79:3949-61. [PMID: 15767397 PMCID: PMC1061567 DOI: 10.1128/jvi.79.7.3949-3961.2005] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Herpes simplex virus type 1 (HSV-1) protein ICP27 interacts with the cellular export adaptor protein Aly/REF, which is part of the exon junction complex implicated in cellular mRNA export. We previously reported that Aly/REF was no longer associated with splicing factor SC35 sites during infection but instead colocalized with ICP27 in distinct structures. Here we show that these structures colocalize with ICP4 and are sites of HSV-1 transcription. ICP27 mutants with lesions in the region required for the interaction with Aly/REF failed to recruit Aly/REF to viral transcription sites; however, ICP27 export to the cytoplasm was unimpaired, indicating that the interaction of ICP27 with Aly/REF is not required for ICP27 shuttling. ICP27 has also been shown to interact with the cellular mRNA export receptor TAP/NXF1. We report that ICP27 interacts directly with TAP/NXF1 and does not require Aly/REF to bridge the interaction. The C terminus of ICP27 is required; however, the N-terminal leucine-rich region also contributes to the interaction of ICP27 with TAP/NXF1. In contrast to the results found for Aly/REF, mutants that failed to interact with TAP/NXF1 were not exported to the cytoplasm, and TAP/NXF1 was not recruited to sites of HSV-1 transcription. Therefore, the interaction of ICP27 with TAP/NXF1 occurs after ICP27 leaves viral transcription sites. We conclude that ICP27 and the viral RNAs to which it binds are exported via the TAP/NXF1 export receptor.
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Affiliation(s)
- I-Hsiung Brandon Chen
- Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine, CA 92697-4025, USA
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13
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Smiley JR. Herpes simplex virus virion host shutoff protein: immune evasion mediated by a viral RNase? J Virol 2004; 78:1063-8. [PMID: 14722261 PMCID: PMC321390 DOI: 10.1128/jvi.78.3.1063-1068.2004] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- James R Smiley
- Department of Medical Microbiology & Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2.
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Sciabica KS, Dai QJ, Sandri-Goldin RM. ICP27 interacts with SRPK1 to mediate HSV splicing inhibition by altering SR protein phosphorylation. EMBO J 2003; 22:1608-19. [PMID: 12660167 PMCID: PMC152910 DOI: 10.1093/emboj/cdg166] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Infection with some viruses can alter cellular mRNA processing to favor viral gene expression. We present evidence that herpes simplex virus 1 (HSV-1) protein ICP27, which contributes to host shut-off by inhibiting pre-mRNA splicing, interacts with essential splicing factors termed SR proteins and affects their phosphorylation. During HSV-1 infection, phosphorylation of several SR proteins was reduced and this correlated with a subnuclear redistribution. Exogenous SR proteins restored splicing in ICP27-inhibited nuclear extracts and SR proteins isolated from HSV-1-infected cells activated splicing in uninfected S100 extracts, indicating that inhibition occurs by a reversible mechanism. Spliceosome assembly was blocked at the pre-spliceosomal complex A stage. Furthermore, we show that ICP27 interacts with SRPK1 and relocalizes it to the nucleus; moreover, SRPK1 activity was altered in the presence of ICP27 in vitro. We propose that ICP27 modifies SRPK1 activity resulting in hypophosphorylation of SR proteins impairing their ability to function in spliceosome assembly.
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Affiliation(s)
- Kathryn S Sciabica
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697, USA
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15
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Chen IHB, Sciabica KS, Sandri-Goldin RM. ICP27 interacts with the RNA export factor Aly/REF to direct herpes simplex virus type 1 intronless mRNAs to the TAP export pathway. J Virol 2002; 76:12877-89. [PMID: 12438613 PMCID: PMC136725 DOI: 10.1128/jvi.76.24.12877-12889.2002] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) protein ICP27 facilitates the export of viral intronless mRNAs. ICP27 shuttles between the nucleus and cytoplasm, which has been shown to require a leucine-rich nuclear export sequence (NES). ICP27 export was reported to be sensitive to the CRM1 inhibitor leptomycin B (LMB) in HSV-1-infected cells but not in Xenopus oocytes, where ICP27 interacts with the export factor Aly/REF to access the TAP export pathway. Here, we show that ICP27 interacts with Aly/REF in HSV-1-infected mammalian cells and that Aly/REF stimulates export of viral intronless RNAs but does not cross-link to these RNAs. During infection, Aly/REF was no longer associated with splicing factor SC35 but moved into structures that colocalized with ICP27, suggesting that ICP27 recruits Aly/REF from spliceosomes to viral intronless RNAs. Further, ICP27 was found to interact in vivo with TAP but not with CRM1. In vitro export assays showed that ICP27 export was not sensitive to LMB but was blocked by a dominant-negative TAP deletion mutant lacking the nucleoporin interaction domain. These data suggest that ICP27 uses the TAP pathway to export viral RNAs. Interestingly, the leucine-rich N-terminal sequence was required for efficient export, even though ICP27 export was LMB insensitive. Thus, this region is required for efficient ICP27 export but does not function as a CRM1-dependent NES.
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Affiliation(s)
- I-Hsiung Brandon Chen
- Department of Microbiology and Molecular Genetics, Medical Sciences I, College of Medicine, University of California, Irvine, CA 92697-4025, USA
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16
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Lengyel J, Guy C, Leong V, Borge S, Rice SA. Mapping of functional regions in the amino-terminal portion of the herpes simplex virus ICP27 regulatory protein: importance of the leucine-rich nuclear export signal and RGG Box RNA-binding domain. J Virol 2002; 76:11866-79. [PMID: 12414929 PMCID: PMC136872 DOI: 10.1128/jvi.76.23.11866-11879.2002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infected-cell protein 27 (ICP27) is an essential herpes simplex virus type 1 (HSV-1) regulatory protein that activates a subset of viral delayed-early and late genes, at least in part through posttranscriptional mechanisms. Previous studies have shown that the amino (N)-terminal half of the protein contains important functional regions, including a leucine-rich nuclear export signal (NES). However, to date, the phenotype of an HSV-1 ICP27 NES mutant has not been reported. In this study, we engineered and characterized dLeu, an HSV-1 deletion mutant that specifically lacks ICP27's NES (amino acids 6 to 19). The phenotype of dLeu was analyzed alongside those of eight other ICP27 N-terminal deletion mutants. We found that in Vero cells, dLeu displays modest defects in viral gene expression and an approximately 100-fold reduction in the production of viral progeny. Unlike wild-type (WT) ICP27, which exhibits a cytoplasmic distribution in addition to its predominant nuclear localization, dLeu ICP27 is highly restricted to the cell nucleus. This strongly suggests that the N-terminal leucine-rich sequence functions as an NES during viral infection. Our analysis of dLeu and the other mutants has enabled us to genetically define the regions in the N-terminal 200 residues of ICP27 which are required for efficient viral growth in Vero cells. Only two regions appear to be important: (i) the leucine-rich NES and (ii) the RGG box RNA-binding domain, encoded by residues 139 to 153. A virus lacking the RGG box-encoding sequence, d4-5, has a phenotype similar to that of dLeu in that it displays modest defects in viral gene expression and grows poorly. Interestingly, deletion of both the NES and RGG box, as well as the sequences in between, is lethal. The resulting virus, d1-5, displays severe defects in viral gene expression and DNA synthesis and is unable to produce significant amounts of infectious progeny. Therefore, the N-terminal portion of ICP27 contains at least two functional domains which collectively are absolutely essential for viral infection.
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Affiliation(s)
- Joy Lengyel
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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Lindberg A, Kreivi JP. Splicing inhibition at the level of spliceosome assembly in the presence of herpes simplex virus protein ICP27. Virology 2002; 294:189-98. [PMID: 11886277 DOI: 10.1006/viro.2001.1301] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Herpes simplex virus (HSV) immediate-early protein ICP27 is a multifunctional regulator of viral and cellular gene expression. It has previously been shown that ICP27 directly or indirectly modulates several posttranscriptional processes, such as pre-mRNA splicing and polyadenylation. We show here that pre-mRNA splicing is inhibited in nuclear extracts prepared from cells in which ICP27 has been transiently expressed. Our results show that splicing inhibition in ICP27 extracts is manifested at early stages of the splicing process. Furthermore, our results suggest that an enzymatic activity in ICP27-containing extracts causes the splicing inhibition.
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Affiliation(s)
- Anette Lindberg
- Unit of Microbiology, Uppsala University, S-751 23 Uppsala, Sweden
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Ahmed M, Fraser NW. Herpes simplex virus type 1 2-kilobase latency-associated transcript intron associates with ribosomal proteins and splicing factors. J Virol 2001; 75:12070-80. [PMID: 11711597 PMCID: PMC116102 DOI: 10.1128/jvi.75.24.12070-12080.2001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During latency of herpes simplex virus type 1 in sensory neurons, the transcription of viral genes is restricted to the latency-associated transcripts (LATs). The stable 2-kb LAT intron has been characterized previously and has been shown to accumulate to high levels in the nuclei of infected neurons. However, in productively infected tissue culture cells, this unique intron is also found in the cytoplasm. Although deletion mutant analysis has suggested that the region of the gene from which the intron is spliced plays a role in maintenance of latency or in reactivation from latency, no well-defined function has been ascribed specifically to the 2-kb LAT intron. Nevertheless, previous work has shown that it associates with 50S particles in the cytoplasm of acutely infected cells. Our studies tested the ability of the 2-kb LAT to dissociate from cytoplasmic protein complexes under various salt conditions. Results indicated that this association, which had been speculated to be mRNA-like, is actually more similar to the affinity of rRNAs for translational complexes. Furthermore, by immunoprecipitation analysis, we demonstrate that the 2-kb LAT associates with ribosomal as well as with splicing complexes in infected cells. Our results suggest that the 2-kb LAT is processed similarly to mRNAs in the nuclei of infected cells. However, in the cytoplasm, the 2-kb LAT may play a structural role in the ribosomal complex, similar to that of the cellular rRNAs, and therefore affect the functioning of the translational machinery.
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Affiliation(s)
- M Ahmed
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Nuclear Export of Herpes Virus RNA. Curr Top Microbiol Immunol 2001. [DOI: 10.1007/978-3-642-56597-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Cheung P, Ellison KS, Verity R, Smiley JR. Herpes simplex virus ICP27 induces cytoplasmic accumulation of unspliced polyadenylated alpha-globin pre-mRNA in infected HeLa cells. J Virol 2000; 74:2913-9. [PMID: 10684311 PMCID: PMC111785 DOI: 10.1128/jvi.74.6.2913-2919.2000] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcripts of most intron-bearing cellular genes must be processed by the splicing machinery in order to efficiently accumulate and gain access to the cytoplasm. However, we found that herpes simplex virus induces cytoplasmic accumulation of both spliced and unspliced polyadenylated alpha-globin RNAs in infected HeLa cells. Accumulation of the unspliced RNA required the immediate-early protein ICP27, and ICP27 was sufficient (in combination with ICP4) to produce this effect in a transient-transfection assay. However, expression of ICP27 did not markedly alter the levels of fully spliced alpha-globin transcripts in infected cells. These data demonstrate that the previously documented effects of ICP27 on the cellular splicing apparatus do not greatly inhibit splicing of alpha-globin RNA and argue that ICP27 induces a splicing-independent pathway for alpha-globin RNA accumulation and nuclear export.
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Affiliation(s)
- P Cheung
- Departments of Biology, McMaster University, Hamilton, Ontario L8N 3Z5
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21
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Bello LJ, Davison AJ, Glenn MA, Whitehouse A, Rethmeier N, Schulz TF, Barklie Clements J. The human herpesvirus-8 ORF 57 gene and its properties. J Gen Virol 1999; 80 ( Pt 12):3207-3215. [PMID: 10567653 DOI: 10.1099/0022-1317-80-12-3207] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human herpesvirus-8 (HHV-8) is a gamma(2) lymphotropic herpesvirus associated with Kaposi's sarcoma, a major neoplasm of AIDS patients, and with other AIDS-related neoplasms. The HHV-8 ORF 57 gene is conserved throughout the herpesvirus family and has a herpes simplex virus type 1 homologue, IE63 (also termed ICP27), which is an essential regulatory protein and acts at both transcriptional and post-transcriptional levels. We show that, contrary to the published HHV-8 sequence, which predicts a protein of 275 amino acids, the ORF 57 gene is spliced, contains a single intron and encodes a protein of 455 amino acids. For several gammaherpesviruses examined, the upstream coding exon is 16-17 amino acids in length and is rich in methionine residues. When ORF 57 was fused to the gene for enhanced green fluorescent protein (EGFP), the fusion protein exhibited a punctate nuclear distribution that co-localized with the cellular splicing factor SC-35. Unlike the IE63-EGFP fusion protein, ORF 57-EGFP did not shuttle from the nucleus to the cytoplasm in the presence of actinomycin D. However, ORF 57-EGFP was capable of shuttling from a transfected monkey nucleus to a recipient mouse nucleus in an interspecies heterokaryon assay. These data indicate that HHV-8 ORF 57 and IE63 possess certain common properties.
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Affiliation(s)
- Leonard J Bello
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA2
- Institute of Virology, University of Glasgow, Church Street, Glasgow G11 5JR, UK1
| | - Andrew J Davison
- Institute of Virology, University of Glasgow, Church Street, Glasgow G11 5JR, UK1
| | - Mark A Glenn
- Department of Medical Microbiology, University of Liverpool, UK3
| | | | - Nikki Rethmeier
- Institute of Virology, University of Glasgow, Church Street, Glasgow G11 5JR, UK1
| | - Thomas F Schulz
- Department of Medical Microbiology, University of Liverpool, UK3
| | - J Barklie Clements
- Institute of Virology, University of Glasgow, Church Street, Glasgow G11 5JR, UK1
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Wagner EK, Petroski MD, Pande NT, Lieu PT, Rice M. Analysis of factors influencing kinetics of herpes simplex virus transcription utilizing recombinant virus. Methods 1998; 16:105-16. [PMID: 9774520 DOI: 10.1006/meth.1998.0648] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The herpes simplex virus type 1 (HSV-1) transcription program is a regulated cascade in which early and late phases of gene expression are separated by viral DNA replication. While promoters controlling expression of transcripts encoding immediate-early proteins contain virus-specific cis-acting elements, these are in the context of cellular promoter elements, and the promoters controlling expression of other viral transcripts contain only cellular cis-acting elements. We had developed and continue to refine a general method for the production of recombinant viruses in which modified promoters can be inserted into nonessential loci within the viral genome through homologous recombination. This approach has been especially useful in defining the features of model promoters of the various kinetic classes. Our work suggests that class-specific differences in promoter architecture are critical factors in the ability of the cellular transcription machinery to form stable preinitiation complexes at various phases of infection and, thus, mediate kinetic class-specific transcription. Early (beta) promoters contain a TATA box and upstream activation elements while sequences downstream of the TATA homology are dispensible for transcription. Late transcripts can be catagorized as either leaky-late (beta gamma) or strict late (gamma) depending on whether they are readily detectable prior to viral DNA replication. Promoters controlling both types are clearly distinct from early ones in that sequences near the transcription start site which resemble consensus mammalian initiator elements are required along with the TATA box and activator elements. Strict late promoters do not contain elements upstream of the TATA box but include what appears to be a class specific element downstream of the transcription start site.
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Affiliation(s)
- E K Wagner
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, 92697-3900, USA.
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