scholarly journals Tilapia dsRNA-activated protein kinase R (PKR): An interferon-induced antiviral effector with translation inhibition activity

2021 ◽  
Vol 112 ◽  
pp. 74-80
Author(s):  
Zhen Gan ◽  
Jun Cheng ◽  
Jing Hou ◽  
Shannan Chen ◽  
Hongli Xia ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Inhibition Activity ◽  
Protein Kinase R ◽  
Translation Inhibition

scholarly journals TRBP Control of PACT-Induced Phosphorylation of Protein Kinase R Is Reversed by Stress

2008 ◽  
Vol 29 (1) ◽  
pp. 254-265 ◽  
Author(s):  
Aïcha Daher ◽  
Ghislaine Laraki ◽  
Madhurima Singh ◽  
Carlos E. Melendez-Peña ◽  
Sylvie Bannwarth ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Hela Cells ◽  
Rna Binding ◽  
Luciferase Assay ◽  
Serum Starvation ◽  
Protein Kinase R ◽  
Translation Inhibition ◽  
Binding Domains ◽  
Immunodeficiency Virus ◽  
Terminal Amino

ABSTRACT The TAR RNA binding Protein, TRBP, inhibits the activity of the interferon-induced protein kinase R (PKR), whereas the PKR activator, PACT, activates its function. TRBP and PACT also bind to each other through their double-stranded RNA binding domains (dsRBDs) and their Medipal domains, which may influence their activity on PKR. In a human immunodeficiency virus (HIV) long terminal repeat-luciferase assay, PACT unexpectedly reversed PKR-mediated inhibition of gene expression. In a translation inhibition assay in HeLa cells, PACT lacking the 13 C-terminal amino acids (PACTΔ13), but not full-length PACT, activated PKR and enhanced interferon-mediated repression. In contrast, in the astrocytic U251MG cells that express low TRBP levels, both proteins activate PKR, but PACTΔ13 is stronger. Immunoprecipitation assays and yeast two-hybrid assays show that TRBP and PACTΔ13 interact very weakly due to a loss of binding in the Medipal domain. PACT-induced PKR phosphorylation was restored in Tarbp2 −/− murine tail fibroblasts and in HEK293T or HeLa cells when TRBP expression was reduced by RNA interference. In HEK293T and HeLa cells, arsenite, peroxide, and serum starvation-mediated stresses dissociated the TRBP-PACT interaction and increased PACT-induced PKR activation, demonstrating the relevance of this control in a physiological context. Our results demonstrate that in cells, TRBP controls PACT activation of PKR, an activity that is reversed by stress.

scholarly journals Immunoproteasome induction is suppressed in hepatitis C virus-infected cells in a protein kinase R-dependent manner

2016 ◽  
Vol 48 (11) ◽  
pp. e270-e270 ◽  
Author(s):  
In Soo Oh ◽  
Kathrin Textoris-Taube ◽  
Pil Soo Sung ◽  
Wonseok Kang ◽  
Xenia Gorny ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protein Kinase ◽  
Dependent Manner ◽  
Protein Kinase R ◽  
Infected Cells

scholarly journals Puumala and Andes Orthohantaviruses Cause Transient Protein Kinase R-Dependent Formation of Stress Granules

2019 ◽  
Vol 94 (3) ◽  
Author(s):  
Wanda Christ ◽  
Janne Tynell ◽  
Jonas Klingström
Keyword(s):  
Protein Kinase ◽  
Host Cell ◽  
Stress Responses ◽  
Stress Granules ◽  
Cell Stress ◽  
Stress Granule ◽  
Hantavirus Infection ◽  
Stress Signaling ◽  
Protein Kinase R ◽  
Granule Formation

ABSTRACT Virus infection frequently triggers host cell stress signaling resulting in translational arrest; as a consequence, many viruses employ means to modulate the host stress response. Hantaviruses are negative-sense, single-stranded RNA viruses known to inhibit host innate immune responses and apoptosis, but their impact on host cell stress signaling remains largely unknown. In this study, we investigated activation of host cell stress responses during hantavirus infection. We show that hantavirus infection causes transient formation of stress granules (SGs) but does so in only a limited proportion of infected cells. Our data indicate some cell type-specific and hantavirus species-specific variability in SG prevalence and show SG formation to be dependent on the activation of protein kinase R (PKR). Hantavirus infection inhibited PKR-dependent SG formation, which could account for the transient nature and low prevalence of SG formation observed during hantavirus infection. In addition, we report only limited colocalization of hantaviral proteins or RNA with SGs and show evidence indicating hantavirus-mediated inhibition of PKR-like endoplasmic reticulum (ER) kinase (PERK). IMPORTANCE Our work presents the first report on stress granule formation during hantavirus infection. We show that hantavirus infection actively inhibits stress granule formation, thereby escaping the detrimental effects on global translation imposed by host stress signaling. Our results highlight a previously uncharacterized aspect of hantavirus-host interactions with possible implications for how hantaviruses are able to cause persistent infection in natural hosts and for pathogenesis.

Distinct roles of protein kinase R and toll-like receptor 3 in the activation of astrocytes by viral stimuli

Glia ◽  
2006 ◽  
Vol 55 (3) ◽  
pp. 239-252 ◽  
Author(s):  
Pamela A. Carpentier ◽  
Bryan R. Williams ◽  
Stephen D. Miller
Keyword(s):  
Protein Kinase ◽  
Toll Like Receptor ◽  
Protein Kinase R

scholarly journals Hepatic stellate cell proliferation: A potential role of protein kinase R

Hepatology ◽  
2011 ◽  
Vol 54 (4) ◽  
pp. 1484-1485 ◽  
Author(s):  
Sara Ceccarelli ◽  
Nadia Panera ◽  
Anna Alisi ◽  
Valerio Nobili
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase ◽  
Hepatic Stellate Cell ◽  
Potential Role ◽  
Stellate Cell ◽  
Protein Kinase R

scholarly journals A Single Amino Acid Dictates Protein Kinase R Susceptibility to Unrelated Viral Antagonists

2016 ◽  
Vol 12 (10) ◽  
pp. e1005966 ◽  
Author(s):  
Kathryn S. Carpentier ◽  
Nicolle M. Esparo ◽  
Stephanie J. Child ◽  
Adam P. Geballe
Keyword(s):  
Amino Acid ◽  
Protein Kinase ◽  
Single Amino Acid ◽  
Protein Kinase R ◽  
Viral Antagonists

scholarly journals The Stress Granule Protein G3BP1 Recruits Protein Kinase R To Promote Multiple Innate Immune Antiviral Responses

2014 ◽  
Vol 89 (5) ◽  
pp. 2575-2589 ◽  
Author(s):  
Lucas C. Reineke ◽  
Richard E. Lloyd
Keyword(s):  
Protein Kinase ◽  
Antiviral Activity ◽  
Cellular Stress ◽  
Stress Granules ◽  
Innate Immune ◽  
Stress Granule ◽  
Productive Infection ◽  
Antiviral Protein ◽  
Protein Kinase R ◽  
Transcriptional Responses

ABSTRACTStress granules (SGs) are cytoplasmic storage sites containing translationally silenced mRNPs that can be released to resume translation after stress subsides. We previously showed that poliovirus 3C proteinase cleaves the SG-nucleating protein G3BP1, blocking the ability of cells to form SGs late in infection. Many other viruses also target G3BP1 and inhibit SG formation, but the reasons why these functions evolved are unclear. Previously, we also showed a link between G3BP1-induced SGs and protein kinase R (PKR)-mediated translational control, but the mechanism of PKR interplay with SG and the antiviral consequences are unknown. Here, we show that G3BP1 exhibits antiviral activity against several enteroviruses, whereas truncated G3BP1 that cannot form SGs does not. G3BP1-induced SGs are linked to activation of innate immune transcriptional responses through NF-κB and JNK. The G3BP1-induced SGs also recruit PKR and other antiviral proteins. We show that the PXXP domain within G3BP1 is essential for the recruitment of PKR to SGs, for eIF2α phosphorylation driven by PKR, and for nucleating SGs of normal composition. We also show that deletion of the PXXP domain in G3BP1 compromises its antiviral activity. These findings tie PKR activation to its recruitment to SGs by G3BP1 and indicate that G3BP1 promotes innate immune responses at both the transcriptional and translational levels and integrates cellular stress responses and innate immunity.IMPORTANCEStress granules appear during virus infection, and their importance is not well understood. Previously, it was assumed that they were nonfunctional artifacts associated with cellular stress. PKR is a well-known antiviral protein; however, its regulation in cells is not well understood. Our work links cellular stress granules with activation of PKR and other innate immune pathways through the activity of G3BP1, a critical stress granule component. The ability of stress granules and G3BP1 to activate PKR and other innate immune transcriptional responses indicates that G3BP1 is an antiviral protein. This work helps to refine a longstanding paradigm indicating stress granules are inert structures and explains why G3BP1 is subverted by many viruses to promote a productive infection.

Sign in / Sign up

Export Citation Format

Share Document