Distinctive Roles for 2′,5′-Oligoadenylate Synthetases and Double-Stranded RNA-Dependent Protein Kinase R in the In Vivo Antiviral Effect of an Adenoviral Vector Expressing Murine IFN-β

Proteins encoded by five of the six known Fanconi anemia (FA) genes form a heteromeric complex that facilitates repair of DNA damage induced by cross-linking agents. A certain number of these proteins, notably FANCC, also function independently to modulate apoptotic signaling, at least in part, by suppressing ground state activation of the pro-apoptotic interferon-inducible double-stranded RNA-dependent protein kinase (PKR). Because certain FANCC mutations interdict its anti-apoptotic function without interfering with the capacity of FANCC to participate functionally in the FA multimeric complex, we suspected that FANCC enhances cell survival independent of its participation in the complex. By investigating this function in both mammalian cells and in yeast, an organism with no FA orthologs, we show that FANCC inhibited the kinase activity of PKR bothin vivoandin vitro, and this effect depended upon a physical interaction between FANCC and Hsp70 but not on interactions of FANCC with other Fanconi proteins. Hsp70, FANCC, and PKR form a ternary complex in lymphoblasts and in yeast expressing PKR. We conclude that Hsp70 requires the cooperation of FANCC to suppress PKR activity and support survival of hematopoietic cells and that FANCC does not require the multimeric FA complex to exert this function.

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IRF3 and IRF7 Phosphorylation in Virus-infected Cells Does Not Require Double-stranded RNA-dependent Protein Kinase R or IκB Kinase but Is Blocked by Vaccinia Virus E3L Protein

Journal of Biological Chemistry ◽

10.1074/jbc.m008717200 ◽

2000 ◽

Vol 276 (12) ◽

pp. 8951-8957 ◽

Cited By ~ 182

Author(s):

Eric J. Smith ◽

Isabelle Marié ◽

Arun Prakash ◽

Adolfo Garcı́a-Sastre ◽

David E. Levy

Keyword(s):

Protein Kinase ◽

Vaccinia Virus ◽

Protein Kinase R ◽

Dependent Protein Kinase ◽

Double Stranded Rna ◽

Iκb Kinase ◽

Dependent Protein ◽

Infected Cells

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The VP35 Protein of Ebola Virus Inhibits the Antiviral Effect Mediated by Double-Stranded RNA-Dependent Protein Kinase PKR

Journal of Virology ◽

10.1128/jvi.01006-06 ◽

2006 ◽

Vol 81 (1) ◽

pp. 182-192 ◽

Cited By ~ 125

Author(s):

Zongdi Feng ◽

Melissa Cerveny ◽

Zhipeng Yan ◽

Bin He

Keyword(s):

Protein Kinase ◽

Ebola Virus ◽

Rna Binding ◽

Antiviral Effect ◽

Vero Cells ◽

Binding Motif ◽

Dependent Protein Kinase ◽

Double Stranded Rna ◽

Beta Interferon ◽

Dependent Protein

ABSTRACT The VP35 protein of Ebola virus is a viral antagonist of interferon. It acts to block virus or double-stranded RNA-mediated activation of interferon regulatory factor 3, a transcription factor that facilitates the expression of interferon and interferon-stimulated genes. In this report, we show that the VP35 protein is also able to inhibit the antiviral response induced by alpha interferon. This depends on the VP35 function that interferes with the pathway regulated by double-stranded RNA-dependent protein kinase PKR. When expressed in a heterologous system, the VP35 protein enhanced viral polypeptide synthesis and growth in Vero cells pretreated with alpha/beta interferon, displaying an interferon-resistant phenotype. In correlation, phosphorylation of PKR and eIF-2α was suppressed in cells expressing the VP35 protein. This activity of the VP35 protein was required for efficient viral replication in PKR+/+ but not PKR−/− mouse embryo fibroblasts. Furthermore, VP35 appears to be a RNA binding protein. Notably, a deletion of amino acids 1 to 200, but not R312A substitution in the RNA binding motif, abolished the ability of the VP35 protein to confer viral resistance to interferon. However, the R312A substitution rendered the VP35 protein unable to inhibit the induction of the beta interferon promoter mediated by virus infection. Together, these results show that the VP35 protein targets multiple pathways of the interferon system.

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Inhibition of double stranded RNA dependent protein kinase (PKR) abrogates isoproterenol induced myocardial ischemia in vitro in cultured cardiomyocytes and in vivo in wistar rats

European Journal of Pharmacology ◽

10.1016/j.ejphar.2021.174223 ◽

2021 ◽

pp. 174223

Author(s):

Sureshbabu Mangali ◽

Audesh Bhat ◽

Deepika Dasari ◽

Dharmarajan Sriram ◽

Arti Dhar

Keyword(s):

Protein Kinase ◽

Myocardial Ischemia ◽

Wistar Rats ◽

Dependent Protein Kinase ◽

Double Stranded Rna ◽

Dependent Protein ◽

Cultured Cardiomyocytes

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NSs Protein of Rift Valley Fever Virus Induces the Specific Degradation of the Double-Stranded RNA-Dependent Protein Kinase

Journal of Virology ◽

10.1128/jvi.02148-08 ◽

2009 ◽

Vol 83 (9) ◽

pp. 4365-4375 ◽

Cited By ~ 166

Author(s):

Matthias Habjan ◽

Andreas Pichlmair ◽

Richard M. Elliott ◽

Anna K. Överby ◽

Timo Glatter ◽

...

Keyword(s):

Protein Kinase ◽

Rift Valley Fever ◽

Rift Valley Fever Virus ◽

Wild Type ◽

Dependent Protein Kinase ◽

Valley Fever ◽

Double Stranded Rna ◽

Dependent Protein ◽

Specific Degradation

ABSTRACT Rift Valley fever virus (RVFV) continues to cause large outbreaks of acute febrile and often fatal illness among humans and domesticated animals in Africa, Saudi Arabia, and Yemen. The high pathogenicity of this bunyavirus is mainly due to the viral protein NSs, which was shown to prevent transcriptional induction of the antivirally active type I interferons (alpha/beta interferon [IFN-α/β]). Viruses lacking the NSs gene induce synthesis of IFNs and are therefore attenuated, whereas the noninducing wild-type RVFV strains can only be inhibited by pretreatment with IFN. We demonstrate here in vitro and in vivo that a substantial part of the antiviral activity of IFN against RVFV is due to a double-stranded RNA-dependent protein kinase (PKR). PKR-mediated virus inhibition, however, was much more pronounced for the strain Clone 13 with NSs deleted than for the NSs-expressing strain ZH548. In vivo, Clone 13 was nonpathogenic for wild-type (wt) mice but could regain pathogenicity if mice lacked the PKR gene. ZH548, in contrast, killed both wt and PKR knockout mice indiscriminately. ZH548 was largely resistant to the antiviral properties of PKR because RVFV NSs triggered the specific degradation of PKR via the proteasome. The NSs proteins of the related but less virulent sandfly fever Sicilian virus and La Crosse virus, in contrast, had no such anti-PKR activity despite being efficient suppressors of IFN induction. Our data suggest that RVFV NSs has gained an additional anti-IFN function that may explain the extraordinary pathogenicity of this virus.

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Functional Domains and the Antiviral Effect of the Double-Stranded RNA-Dependent Protein Kinase PKR from Paralichthys olivaceus

Journal of Virology ◽

10.1128/jvi.02385-07 ◽

2008 ◽

Vol 82 (14) ◽

pp. 6889-6901 ◽

Cited By ~ 83

Author(s):

Rong Zhu ◽

Yi-Bing Zhang ◽

Qi-Ya Zhang ◽

Jian-Fang Gui

Keyword(s):

Protein Kinase ◽

Paralichthys Olivaceus ◽

Protein Translation ◽

Antiviral Effect ◽

Terminal Region ◽

Functional Domains ◽

Dependent Protein Kinase ◽

Double Stranded Rna ◽

Eif2α Phosphorylation ◽

Dependent Protein

ABSTRACT The double-stranded RNA (dsRNA)-dependent protein kinase PKR is thought to mediate a conserved antiviral pathway by inhibiting viral protein synthesis via the phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2α). However, little is known about the data related to the lower vertebrates, including fish. Recently, the identification of PKR-like, or PKZ, has addressed the question of whether there is an orthologous PKR in fish. Here, we identify the first fish PKR gene from the Japanese flounder Paralichthys olivaceus (PoPKR). PoPKR encodes a protein that shows a conserved structure that is characteristic of mammalian PKRs, having both the N-terminal region for dsRNA binding and the C-terminal region for the inhibition of protein translation. The catalytic activity of PoPKR is further evidence that it is required for protein translation inhibition in vitro. PoPKR is constitutively transcribed at low levels and is highly induced after virus infection. Strikingly, PoPKR overexpression increases eIF2α phosphorylation and inhibits the replication of Scophthalmus maximus rhabdovirus (SMRV) in flounder embryonic cells, whereas phosphorylation and antiviral effects are impaired in transfected cells expressing the catalytically inactive PKR-K421R variant, indicating that PoPKR inhibits virus replication by phosphorylating substrate eIF2α. The interaction between PoPKR and eIF2α is demonstrated by coimmunoprecipitation assays, and the transfection of PoPKR-specific short interfering RNA further reveals that the enhanced eIF2α phosphorylation is catalyzed by PoPKR during SMRV infection. The current data provide significant evidence for the existence of a PKR-mediated antiviral pathway in fish and reveal considerable conservation in the functional domains and the antiviral effect of PKR proteins between fish and mammals.

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