Murine Cytomegalovirus Protein pM79 is a Key Regulator for Viral Late Transcription
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ABSTRACT:
ORGANISM(S): Mus musculus Murid betaherpesvirus 1
PROVIDER: GSE47586 | GEO | 2013/07/31
SECONDARY ACCESSION(S): PRJNA206408
REPOSITORIES: GEO
Similar Datasets
Project description:We characterized the role of the conserved murine cytomegalovirus (MCMV) gene M79. Using a recombinant MCMV virus carrying a tagged M79 coding sequence, we showed that M79 encoded a protein (pM79) which was expressed at late times of infection and localized to nuclear viral replication compartments. M79 transcription was largely dependent on viral DNA synthesis but was markedly stimulated by pM79, suggesting a positive feedback loop. To investigate its role, we created the recombinant virus SMin79, in which the M79 coding sequence was disrupted by an 88-nt insertion. We subsequently repaired the mutation to generate marker-rescued virus SMrev79. While SMrev79 grew efficiently in fibroblasts, SMin79 failed to produce infectious progeny but was rescued by pM79 expression in trans. During SMin79 infection, representative viral immediate early and early gene products, as well as viral DNA, accumulated efficiently. Formation of viral replication compartments also appeared normal. Pulsed field gel electrophoresis analysis indicated that the overall structure of replicating viral DNA was indistinguishable in cells infected with SMin79 compared to that with wild type virus. However, the accumulation of viral products for late gene M55 was severely compromised. Viral oligonucleotide tiled array analysis revealed that the accumulation of many late transcripts, defined by their sensitivity to viral DNA synthesis inhibitor phosphonoacetic acid, was markedly reduced by pM79 mutation. This study extends our previous work to suggest that cytomegaloviruses use a conserved mechanism to promote transcription at late stages of infection, and that pM79 regulates expression of a subset of viral DNA synthesis-dependent transcripts. This study consists of 4 unreplicated samples. RNA from Mock-infected, WT infected, WT infected in the presence of PAA, and a mutant M79 version of MCMV.
2013-07-31 | E-GEOD-47586 | biostudies-arrayexpress
Project description:Herpesvirus late promoters activate gene expression after viral DNA synthesis has begun. Alphaherpesviruses utilize a viral immediate-early protein to do this, whereas beta- and gammaherpesviruses primarily use a 6-member set of viral late-acting transcription factors (LTF) that are drawn to a TATT sequence in the late promoter. The betaherpesvirus, human cytomegalovirus (HCMV), produces three immediate-early 2 protein isoforms, IE2-86, IE2-60, IE2-40, in late infection, but whether they activate late viral promoters is unknown. Here, we quickly degrade the IE2 proteins in late infection and analyze effects on transcription using customized PRO-Seq and computational methods combined with multiple validation methods. We discover that the IE2 proteins selectively drive RNA Pol II transcription initiation at a subset of viral early-late and late promoters common to different HCMV strains, but do not substantially affect Pol II transcription of the 9,942 expressed host genes. Most of the IE2-activated viral late infection promoters lack the TATT sequence bound by the HCMV UL87-encoded LTF. The HCMV TATT-binding protein is not mechanistically involved in late RNA expression from the IE2-activated TATT-less UL83 (pp65) promoter, as it is for the TATT-containing UL82 (pp71) promoter. While antecedent viral DNA synthesis is necessary for transcription from the late infection viral promoters, continued viral DNA synthesis is unnecessary. We conclude that the IE2 proteins target a distinct subset of late infection HCMV promoters for transcription initiation by RNA Pol II. Commencement of viral DNA replication renders the HCMV genome late promoters susceptible to late-acting viral transcription factors, which do not appreciably affect host transcription during this late time.
2020-03-05 | GSE139114 | GEO
Project description:During viral infections cellular gene expression is subject to rapid alterations induced by both viral and antiviral mechanisms. In this study, we applied metabolic labeling of newly transcribed RNA with 4-thiouridine (4sU-tagging) to dissect the real-time kinetics of cellular and viral transcriptional activity during lytic murine cytomegalovirus (MCMV) infection. Microarray profiling on newly transcribed RNA obtained from different times during the first six hours of MCMV infection revealed discrete functional networks of cellular genes regulated with distinct kinetics at surprising temporal resolution. Most of these were undetectable in total RNA, either due to low temporal sensitivity of standard gene expression profiling using total RNA, or due to rapid (viral) counter-regulation. Furthermore, metabolic labeling and purification of newly transcribed RNA detailed the real-time kinetics and regulation of viral gene expression in absence of any interfering virion-associated RNA. Both qRT-PCR and next-generation sequencing of newly transcribed RNA demonstrated an unexpected peak of viral gene expression during the first two hours of infection including transcription of immediate early, early and even well characterized late genes. Interestingly, this peak was subject to rapid gene silencing (independent of the multiplicity of infection) with similar transcriptional activity only reached late in infection. For some genes, e.g. m152, this resulted in massive down-regulation of transcriptional activity by 6 hours post infection, which was not even reversed late in infection. Our findings thus highlight the importance of transcriptional activity during the first few hours of CMV infection and hint at novel mechanisms governing the kinetics of viral gene expression. In conclusion, studying real-time transcriptional activity during lytic CMV infection provides intriguing new insights into the regulation of cellular and viral gene expression. In total 13 samples were examined: 3 samples of total RNA (mock, 25, 48 hours past MCMV infection), 3 samples pre-existing RNA (mock, 25, 48 hpi), and 7 samples newly-transcribed RNA (mock, 1-2, 5-6, 11-12, 18-19, 24-25, 47-48 hpi)
2013-02-14 | E-GEOD-35833 | biostudies-arrayexpress
Project description:Expression data from NIH-3T3 cells left uninfected or infected with MCMV for 2, 4 or 6h on total RNA as well as newly transcribed RNA labeled for 1-2, 3-4, and 5-6hpi. For newly transcribed RNA, the isolated RNA was labeled for 1h and separated from total cellular RNA following Trizol RNA preparation and thiol-specific biotinylation. We used microarrays to analyze the effects of MCMV infection in total and newly transcribed RNA. During viral infections cellular gene expression is subject to rapid alterations induced by both viral and antiviral mechanisms. In this study, we applied metabolic labeling of newly transcribed RNA with 4-thiouridine (4sU-tagging) to dissect the real-time kinetics of cellular and viral transcriptional activity during lytic murine cytomegalovirus (MCMV) infection. Microarray profiling on newly transcribed RNA obtained from different times during the first six hours of MCMV infection revealed discrete functional networks of cellular genes regulated with distinct kinetics at surprising temporal resolution. Most of these were undetectable in total RNA, either due to low temporal sensitivity of standard gene expression profiling using total RNA, or due to rapid (viral) counter-regulation. Furthermore, metabolic labeling and purification of newly transcribed RNA detailed the real-time kinetics and regulation of viral gene expression in absence of any interfering virion-associated RNA. Both qRT-PCR and next-generation sequencing of newly transcribed RNA demonstrated an unexpected peak of viral gene expression during the first two hours of infection including transcription of immediate early, early and even well characterized late genes. Interestingly, this peak was subject to rapid gene silencing (independent of the multiplicity of infection) with similar transcriptional activity only reached late in infection. For some genes, e.g. m152, this resulted in massive down-regulation of transcriptional activity by 6 hours post infection, which was not even reversed late in infection. Our findings thus highlight the importance of transcriptional activity during the first few hours of CMV infection and hint at novel mechanisms governing the kinetics of viral gene expression. In conclusion, studying real-time transcriptional activity during lytic CMV infection provides intriguing new insights into the regulation of cellular and viral gene expression. NIH-3T3 cells (5th to 15th passage after thawing) were split from confluent plates 24h before start of the experiment. At the beginning of the experiment about 80% confluency was reached. The experiment was started by applying fresh, prewarmed, CO2-equilibrated medium containing either mock or MCMV particles (MOI 1). The MOI was increased by ~10-fold through centrifugal enhancement (2000g, 30min). Labeling was started 1, 3, or 5hpi after the end of centrifugal enhancement.
2013-02-01 | E-GEOD-35919 | biostudies-arrayexpress
Project description:Natural killer (NK) cells are innate lymphocytes that have been recently appreciated to display features of adaptive immunity in response to viral infection. Biallelic mutations in the IRF8 gene have been reported to cause familial NK cell deficiency and susceptibility to severe viral infection in humans; however, the precise role of this transcription factor in regulating NK cell function remained unknown. Here, we show that IRF8 is required in a cell-intrinsic manner for NK cell-mediated protection against mouse cytomegalovirus (MCMV) infection. During exposure to MCMV, IRF8 is robustly upregulated in NK cells by IL-12 and STAT4, which promotes epigenetic remodeling of the Irf8 locus. Moreover, IRF8 facilitates the proliferative burst of virus-specific NK cells by promoting expression of a suite of DNA replication and cell cycle genes, and directly regulating Zbtb32, a master regulator of NK cell proliferation during viral challenge. These results identify a novel function and cell-type specific regulation for IRF8 in host antiviral immunity, and provide a mechanistic understanding of virus susceptibility in patients with IRF8 mutations.
2018-05-16 | GSE112948 | GEO
Project description:Expression data from NIH-3T3 cells left uninfected or infected with MCMV for 2, 4 or 6h on total RNA as well as newly transcribed RNA labeled for 1-2, 3-4, and 5-6hpi. For newly transcribed RNA, the isolated RNA was labeled for 1h and separated from total cellular RNA following Trizol RNA preparation and thiol-specific biotinylation. We used microarrays to analyze the effects of MCMV infection in total and newly transcribed RNA. During viral infections cellular gene expression is subject to rapid alterations induced by both viral and antiviral mechanisms. In this study, we applied metabolic labeling of newly transcribed RNA with 4-thiouridine (4sU-tagging) to dissect the real-time kinetics of cellular and viral transcriptional activity during lytic murine cytomegalovirus (MCMV) infection. Microarray profiling on newly transcribed RNA obtained from different times during the first six hours of MCMV infection revealed discrete functional networks of cellular genes regulated with distinct kinetics at surprising temporal resolution. Most of these were undetectable in total RNA, either due to low temporal sensitivity of standard gene expression profiling using total RNA, or due to rapid (viral) counter-regulation. Furthermore, metabolic labeling and purification of newly transcribed RNA detailed the real-time kinetics and regulation of viral gene expression in absence of any interfering virion-associated RNA. Both qRT-PCR and next-generation sequencing of newly transcribed RNA demonstrated an unexpected peak of viral gene expression during the first two hours of infection including transcription of immediate early, early and even well characterized late genes. Interestingly, this peak was subject to rapid gene silencing (independent of the multiplicity of infection) with similar transcriptional activity only reached late in infection. For some genes, e.g. m152, this resulted in massive down-regulation of transcriptional activity by 6 hours post infection, which was not even reversed late in infection. Our findings thus highlight the importance of transcriptional activity during the first few hours of CMV infection and hint at novel mechanisms governing the kinetics of viral gene expression. In conclusion, studying real-time transcriptional activity during lytic CMV infection provides intriguing new insights into the regulation of cellular and viral gene expression.
2013-02-01 | GSE35919 | GEO
Project description:Viral DNA genomes replicating in cells encounter a myriad of host factors that facilitate or hinder viral replication. Viral proteins expressed early during infection modulate host factors interacting with viral genomes, recruiting proteins to promote viral replication, and limiting access to antiviral repressors. Although some host factors manipulated by viruses have been identified, we know little about pathways exploited during infection and how these differ between viruses. To identify cellular processes manipulated during viral replication, we defined proteomes associated with viral genomes during infection with adenovirus, herpes simplex virus and vaccinia virus. We compared enrichment of host factors between virus proteomes and confirmed association with viral genomes and replication compartments. Using adenovirus as an illustrative example, we uncovered host factors deactivated by early viral proteins, and identified a subgroup of nucleolar proteins that aid virus replication. Our datasets provide valuable resources of virus-host interactions that affect proteins on viral genomes.
2017-10-04 | PXD007741 | Pride
Project description:Natural killer (NK) cells play a critical role in early host defense to infected and transformed cells. Here we show that mice deficient in Eri1, a conserved 3M-bM-^@M-^Y-to-5M-bM-^@M-^Y exoribonuclease that represses RNA interference, have a cell-intrinsic defect in NK cell development and maturation. Eri1M-bM-^@M-^S/M-bM-^@M-^S NK cells displayed delayed acquisition of Ly49 receptors in the bone marrow and a selective reduction in Ly49D and Ly49H activating receptors in the periphery. Eri1 was required for immune-mediated control of mouse cytomegalovirus (MCMV) infection. Ly49H+ NK cells deficient in Eri1 failed to expand efficiently during MCMV infection, and virus-specific responses were also diminished among Eri1M-bM-^@M-^S/M-bM-^@M-^S T cells. We identified miRNAs as the major endogenous small RNA target of Eri1 in mouse lymphocytes. Both NK and T cells deficient in Eri1 displayed a global, sequence-independent increase in miRNA abundance. Ectopic Eri1 expression rescued defective miRNA expression in mature Eri1M-bM-^@M-^S/M-bM-^@M-^S T cells. Thus, mouse Eri1 regulates miRNA homeostasis in lymphocytes and is required for normal NK cell development and anti-viral immunity. Small RNA profiling from wildtype and Eri1-deficient mouse CD4+ T cells
2012-07-11 | E-GEOD-31920 | biostudies-arrayexpress
Project description:Paramecium bursaria chlorella virus (PBCV-1), a member of the family Phycodnaviridae, is a large dsDNA, plaque-forming virus that infects the unicellular green alga Chlorella NC64A. The 331 kb PBCV-1 genome is predicted to encode 365 proteins and 11 tRNAs. To follow global transcription during PBCV-1 replication, a microarray containing 50-mer probes to the PBCV-1 365 protein-encoding genes (CDS) was constructed. Competitive hybridization experiments were conducted employing cDNA from poly A-containing RNA obtained from cells at seven time points after virus infection. The results led to the following conclusions: i) the PBCV-1 replication cycle is temporally programmed and regulated; ii) 360 (99%) of the arrayed PBCV-1 CDSs are expressed at some time in the virus life cycle in the laboratory; iii) 227 (62%) of the CDSs are expressed before virus DNA synthesis begins; iv) these 227 CDSs were grouped into two classes: 127 transcripts disappear prior to initiation of virus DNA synthesis (considered early) and 100 transcripts are still detected after virus DNA synthesis begins (considered early/late); v) 133 (36%) of the CDSs are expressed after virus DNA synthesis begins (considered late); vi) expression of most late CDSs is inhibited by adding the DNA replication inhibitor aphidicolin prior to virus infection. This study provides the first comprehensive evaluation of virus gene expression during the PBCV-1 lifecycle.
2010-01-10 | GSE18421 | GEO
Project description:As obligate intracellular pathogens, viruses often activate host metabolic enzymes to supply intermediates that support progeny production. Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of the salvage NAD+ synthesis, is an interferon-inducible protein that inhibits the replication of several RNA and DNA viruses with unknown mechanism. Here we report that NAMPT restricts herpes simplex virus 1 (HSV-1) replication via phosphoribosyl-hydrolase activity toward key viral structural proteins, independent of NAD+ synthesis. Deep mining of enriched phosphopeptides of HSV-1-infected cells identified phosphoribosylated viral structural proteins, particularly glycoproteins and tegument proteins. Indeed, NAMPT dephosphoribosylates viral proteins in vitro and in cells. Chimeric and recombinant HSV-1 carrying phosphoribosylation-resistant mutations show that phosphoribosylation promotes the incorporation of structural proteins into HSV-1 virions and subsequent virus entry. Moreover, loss of NAMPT renders mice highly susceptible to HSV-1 infection. The work describes a hidden enzyme activity of a metabolic enzyme in viral infection and host defense, offering a system to interrogate roles of phosphoribosylation in metazoans.
2024-09-13 | PXD050684 | Pride