Biochemical data from many laboratories have clearly defined PKR as an IFN-inducible gene product whose enzymatic activity is stimulated by dsRNA (2, 10, 20, 27). Because of these properties, PKR has been predicted to play a major role in IFN-mediated antiviral defense. Indeed, PKR demonstrated an antiviral role in cultured cells following various means of overexpression of the wild type or catalytically inactive mutants (21, 22, 28). However, previous studies from our lab and others have failed to demonstrate a definitive role for PKR on an organismal level following genetic ablation of PKR in mice (1, 36). Yang et al. (36) challenged their PKR−/− mice with EMCV (∼1,000 PFU i.v.) and found no difference in survival from that of wild-type animals, but the mice did show a diminished protective effect from pretreatment with either IFN-γ or the dsRNA analogue poly(I · C). In a recent report, Zhou et al. have also shown only a very slight difference in survival between wild-type animals and ... Cellular innate immune sensors detect foreign signals emanating from pathogens. Nallagatla et al. report that the pivotal sensing protein, double-stranded RNA-activated protein kinase (PKR), is finely tuned to recognize the 5′-triphosphate structures of single-stranded RNA molecules present in many bacteria and viruses. This recognition strategy is similar to the recently described detection of nucleic acid 5′-end signatures by another sensing protein, RIG-I. It remains unclear exactly how these key sensors go on to tailor the most appropriate cellular responses to intracellular pathogens.. S. R. Nallagatla, J. Hwang, R. Toroney, X. Zheng, C. E. Cameron, P. C. Bevilacqua, 5′-triphosphate-dependent activation of PKR by RNAs with short stem-loops. Science 318, 1455-1458 (2007). [Abstract] [Full Text]. ... Cytosolic viral RNA recognition by the helicases RIG-I and MDA5 is considered the major pathway for IFN-alpha/beta induction in response to RNA viruses. However, other cytoplasmic RNA sensors, including the double-stranded RNA-binding protein kinase R (PKR), have been implicated in IFN-alpha/beta production, although their relative contribution and mechanism have been unclear. Using cells expressing nonfunctional PKR or reduced levels of kinase, we show that PKR is required for production of IFN-alpha/beta proteins in response to a subset of RNA viruses including encephalomyocarditis, Theilers murine encephalomyelitis, and Semliki Forest virus, but not influenza or Sendai virus. Surprisingly, although IFN-alpha/beta mRNA induction is largely normal in PKR-deficient cells, much of that mRNA lacks the poly(A) tail, indicating that its integrity is compromised. Our results suggest that PKR plays a nonredundant role in IFN-alpha/beta production in response to some but not all viruses, in part by regulating As the spread of sedentary lifestyle and obesity in the modern society, according to the data from World Health Organization (WHO), over 300 million people will suffer from diabetes mellitus by the year 2025 [32]. As one of the chronic cardiac complications, cardiovascular complications are major causes responsible for mortality of diabetes [33, 34]. In diabetes- afflicted population, increased risk for cardiac dysfunction which was termed as DCM which was considered independent from other cardiovascular diseases including hypertension, congenital heart disease, valvular heart diseases and coronary artery disease [35]. Apoptosis of cardiomyocytes is considered as one of the hallmarks of DCM, taking part in pathogenesis and progression of cardiac dysfunction during DCM [5, 36]. In this study, diabetes in rats was mimicked by intraperitoneal injection of STZ which selectively causes damage to islet beta cells to suppress insulin secretion. The induction of DCM was evidenced by cardiac pump and ... ID DNJC3_HUMAN Reviewed; 504 AA. AC Q13217; Q86WT9; Q8N4N2; DT 16-AUG-2005, integrated into UniProtKB/Swiss-Prot. DT 01-NOV-1996, sequence version 1. DT 27-SEP-2017, entry version 163. DE RecName: Full=DnaJ homolog subfamily C member 3; DE AltName: Full=Endoplasmic reticulum DNA J domain-containing protein 6; DE Short=ER-resident protein ERdj6; DE Short=ERdj6; DE AltName: Full=Interferon-induced, double-stranded RNA-activated protein kinase inhibitor; DE AltName: Full=Protein kinase inhibitor of 58 kDa; DE Short=Protein kinase inhibitor p58; DE Flags: Precursor; GN Name=DNAJC3; Synonyms=P58IPK, PRKRI; OS Homo sapiens (Human). OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; OC Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; OC Catarrhini; Hominidae; Homo. OX NCBI_TaxID=9606; RN [1] RP NUCLEOTIDE SEQUENCE [MRNA], AND TISSUE SPECIFICITY. RX PubMed=8666242; DOI=10.1016/0378-1119(95)00883-7; RA Korth M.J., Lyons C.N., Wambach M., Katze M.G.; RT "Cloning, expression, ... TY - JOUR. T1 - The cellular protein P58IPK regulates influenza virus mRNA translation and replication through a PKR-mediated mechanism. AU - Goodman, Alan G.. AU - Smith, Jennifer A.. AU - Balachandran, Siddharth. AU - Perwitasari, Olivia. AU - Proll, Scan C.. AU - Thomas, Matthew J.. AU - Korth, Marcus J.. AU - Barber, Glen N. AU - Schiff, Leslie A.. AU - Katze, Michael G.. PY - 2007/3/1. Y1 - 2007/3/1. N2 - We previously hypothesized that efficient translation of influenza virus mRNA requires the recruitment of P58IPK, the cellular inhibitor of PKR, an interferon-induced kinase that targets the eukaryotic translation initiation factor eIF2α. P58IPK also inhibits PERK, an eIF2α kinase that is localized in the endoplasmic reticulum (ER) and induced during ER stress. The ability of P58IPK to interact with and inhibit multiple eIF2α kinases suggests it is a critical regulator of both cellular and viral mRNA translation. In this study, we sought to definitively define the role of P58IPK during ... Mechanisms of differential NS1 function.There are many reports describing the purported mechanisms by which NS1 functions (1, 4, 9, 17, 20, 25, 28, 31-36, 38, 42, 53), and different regions of the protein mediate specific activities. The N terminus of NS1 binds and sequesters dsRNA, which may thereby block the activation of RIG-I, 2′-5′ OAS, PKR, or other dsRNA-activated proteins. The C terminus of NS1 can block the activity of the nuclear proteins PABPII and CPSF, which prevent the processing and export of mRNA transcripts. The interaction between NS1 and CPSF appears to be stabilized by the viral polymerase complex (specifically PA) and by the viral NP protein, again suggesting that at least some NS1 functions are dependent upon viral gene constellation (26). More recently, an SH3-binding motif on the NS1 C terminus was shown to interact with the p85β subunit of PI3K, which in turn activates the PI3K/Akt pathway in order to mediate anti-apoptotic signaling responses (13, 29, 43, 44, 54). ... cAMP-dependent protein kinase R2. (Aliases: BcDNA:GM01761,pkA,Cos,PKA RII,cos1,Pka-RII,Dmel\CG15862,CG15862,pka-RII,PKa-R2,PKA,Cos1,RII,RII[[DR]],PKA-R2,PKA-RII,Cos-1,Epa) ... Levels of the elF-2a-specific protein kinase, PkR, are higher in several breast carcinoma cell lines including the estrogen-responsive cell lines, MOF-7 and T-47D, as well as estrogen- independent cell lines, BT-20 and MDA-MB-468, compared with the normal breast cell line, Hs578 Bst, or the human HeLa cell line. In contrast, the phosphorylation state of elF-2a is very low in the breast carcinoma cell lines compared to the normal human breast cell line Hs578 Bst and HeLa cells, even at high cell densities, suggesting an inhibition of PkR activity in the breast oarninoma cell lines. In support of this hypothesis, treatment of cells with either alpha- or Beta-interferon, although increasing PKR levels slightly, do not result in higher steady state levels of elF-2a phosphorylation. These results suggest that deregulation of PKR activity is occurring at some level in breast carcinoma cell lines. This deregulation could result from increased levels/activities of cellular PKR inhibitory proteins, or from