scholarly journals Mutations in SARS-CoV-2 ORF8 Altered the Bonding Network With Interferon Regulatory Factor 3 to Evade Host Immune System

2021 ◽  
Vol 12 ◽  
Author(s):  
Farooq Rashid ◽  
Muhammad Suleman ◽  
Abdullah Shah ◽  
Emmanuel Enoch Dzakah ◽  
Haiying Wang ◽  
...  
Keyword(s):  
Immune System ◽  
Nuclear Translocation ◽  
Interferon Regulatory Factor ◽  
Host Immune System ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 3 ◽  
Reading Frame ◽  
Significant Difference ◽  
Dynamics Simulations ◽  
The Impact

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been continuously mutating since its first emergence in early 2020. These alterations have led this virus to gain significant difference in infectivity, pathogenicity, and host immune evasion. We previously found that the open-reading frame 8 (ORF8) of SARS-CoV-2 can inhibit interferon production by decreasing the nuclear translocation of interferon regulatory factor 3 (IRF3). Since several mutations in ORF8 have been observed, therefore, in the present study, we adapted structural and biophysical analysis approaches to explore the impact of various mutations of ORF8, such as S24L, L84S, V62L, and W45L, the recently circulating mutant in Pakistan, on its ability to bind IRF3 and to evade the host immune system. We found that mutations in ORF8 could affect the binding efficiency with IRF3 based on molecular docking analysis, which was further supported by molecular dynamics simulations. Among all the reported mutations, W45L was found to bind most stringently to IRF3. Our analysis revealed that mutations in ORF8 may help the virus evade the immune system by changing its binding affinity with IRF3.

Interferon regulatory factor 3-dependent responses to lipopolysaccharide are selectively blunted in cord blood cells

Blood ◽  
2006 ◽  
Vol 109 (7) ◽  
pp. 2887-2893 ◽  
Author(s):  
Ezra Aksoy ◽  
Valentina Albarani ◽  
Muriel Nguyen ◽  
Jean-Francois Laes ◽  
Jean-Louis Ruelle ◽  
...  
Keyword(s):  
Cord Blood ◽  
Blood Cells ◽  
Nuclear Translocation ◽  
Interferon Regulatory Factor ◽  
Creb Binding Protein ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 3 ◽  
Altered Expression ◽  
Neonatal Blood ◽  
Inducible Genes

AbstractThe synthesis of interferon-β (IFNβ) and IFN-inducible factors elicited by lipopolysaccharide (LPS) depends on the transcriptional activity of interferon regulatory factor 3 (IRF-3) downstream of Toll-like receptor-4 (TLR4). To examine the ability of human newborns to mount TLR4-mediated IRF-3–dependent responses, we analyzed the pattern of genes expressed on the addition of LPS to cord blood or cord blood monocyte-derived dendritic cells (moDCs). Expression of IFNβ and IFN-inducible genes was selectively impaired in neonatal blood and moDCs as compared with their adult counterparts. This selective defect was confirmed by microarray experiments on moDCs. Altered expression of IFN-inducible genes was related to impaired IFNβ synthesis because IFNβ signaling was functional in neonatal moDCs. However, addition of exogenous IFNβ failed to restore LPS-induced IL-12p70 synthesis which was previously shown to be defective in neonatal moDCs. Although LPS-induced IRF-3 nuclear translocation was observed both in adult and neonatal moDCs, IRF-3 DNA-binding activity and association with the coactivator CREB-binding protein (CBP) were decreased in neonatal as compared with adult moDCs. We conclude that impaired IRF-3/CBP interaction in neonatal blood cells exposed to LPS is associated with impaired expression of IFNβ and IFN-inducible genes. Because IRF-3 activity is also required for IL-12p70 synthesis, our findings provide a molecular basis for the decreased ability of LPS-stimulated neonatal moDCs to elicit Th1-type responses.

scholarly journals Distinct Functions of the Mitogen-activated Protein Kinase-activated Protein (MAPKAP) Kinases MK2 and MK3

2011 ◽  
Vol 286 (27) ◽  
pp. 24113-24124 ◽  
Author(s):  
Christian Ehlting ◽  
Natalia Ronkina ◽  
Oliver Böhmer ◽  
Ute Albrecht ◽  
Konrad A. Bode ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Nuclear Translocation ◽  
Interferon Regulatory Factor ◽  
Mitogen Activated Protein Kinase ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 3 ◽  
Downstream Signaling ◽  
Enhanced Expression ◽  
Regulatory Effects

In LPS-treated macrophages, activation of STAT3 is considered to be crucial for terminating the production of inflammatory cytokines. By analyzing the role of MAPK-activated protein kinase (MK) 2 and MK3 for LPS-induced STAT3 activation in macrophages, the present study provides evidence that MK2 is crucial for STAT3 activation in response to LPS because it prevents MK3 from impeding IFNβ gene expression. Accordingly, LPS-induced IFNβ gene expression is down-regulated in MK2-deficient macrophages and can be reconstituted by additional ablation of the MK3 gene in MK2/3−/− macrophages. This is in contrast to LPS-induced IL-10 expression, which essentially requires the presence of MK2. Further analysis of downstream signaling events involved in the transcriptional regulation of IFNβ gene expression suggests that, in the absence of MK2, MK3 impairs interferon regulatory factor 3 protein expression and activation and inhibits nuclear translocation of p65. This inhibition of p65 nuclear translocation coincides with enhanced expression and delayed degradation of IκBβ, whereas expression of IκBα mRNA and protein is impaired in the absence of MK2. The observation that siRNA directed against IκBβ is able to reconstitute IκBα expression in MK2−/− macrophages suggests that enhanced expression and delayed degradation of IκBβ and impaired NFκB-dependent IκBα expression are functionally linked. In summary, evidence is provided that MK2 regulates LPS-induced IFNβ expression and downstream STAT3 activation as it restrains MK3 from mediating negative regulatory effects on NFκB- and interferon regulatory factor 3-dependent LPS signaling.

scholarly journals Structural and Functional Analysis of Interferon Regulatory Factor 3: Localization of the Transactivation and Autoinhibitory Domains

1999 ◽  
Vol 19 (4) ◽  
pp. 2465-2474 ◽  
Author(s):  
Rongtuan Lin ◽  
Yael Mamane ◽  
John Hiscott
Keyword(s):  
Amino Acids ◽  
Dna Binding ◽  
Virus Infection ◽  
Nuclear Translocation ◽  
Sendai Virus ◽  
Interferon Regulatory Factor ◽  
Phosphorylation Sites ◽  
Transactivation Domain ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 3

ABSTRACT The interferon regulatory factor 3 (IRF-3) gene encodes a 55-kDa protein which is expressed constitutively in all tissues. In unstimulated cells, IRF-3 is present in an inactive cytoplasmic form; following Sendai virus infection, IRF-3 is posttranslationally modified by protein phosphorylation at multiple serine and threonine residues located in the carboxy terminus. Virus-induced phosphorylation of IRF-3 leads to cytoplasmic to nuclear translocation of phosphorylated IRF-3, association with the transcriptional coactivator CBP/p300, and stimulation of DNA binding and transcriptional activities of virus-inducible genes. Using yeast and mammalian one-hybrid analysis, we now demonstrate that an extended, atypical transactivation domain is located in the C terminus of IRF-3 between amino acids (aa) 134 and 394. We also show that the C-terminal domain of IRF-3 located between aa 380 and 427 participates in the autoinhibition of IRF-3 activity via an intramolecular association with the N-terminal region between aa 98 and 240. After Sendai virus infection, an intermolecular association between IRF-3 proteins is detected, demonstrating a virus-dependent formation of IRF-3 homodimers; this interaction is also observed in the absence of virus infection with a constitutively activated form of IRF-3. Substitution of the C-terminal Ser-Thr phosphorylation sites with the phosphomimetic Asp in the region ISNSHPLSLTSDQ between amino acids 395 and 407 [IRF-3(5D)], but not the adjacent S385 and S386 residues, generates a constitutively activated DNA binding form of IRF-3. In contrast, substitution of S385 and S386 with either Ala or Asp inhibits both DNA binding and transactivation activities of the IRF-3(5D) protein. These studies thus define the transactivation domain of IRF-3, two domains that participate in the autoinhibition of IRF-3 activity, and the regulatory phosphorylation sites controlling IRF-3 dimer formation, DNA binding activity, and association with the CBP/p300 coactivator.

scholarly journals Cytomegalovirus Activates Interferon Immediate-Early Response Gene Expression and an Interferon Regulatory Factor 3-Containing Interferon-Stimulated Response Element-Binding Complex

1998 ◽  
Vol 18 (7) ◽  
pp. 3796-3802 ◽  
Author(s):  
Lorena Navarro ◽  
Kerri Mowen ◽  
Steven Rodems ◽  
Brian Weaver ◽  
Nancy Reich ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Kinase Inhibitors ◽  
Nuclear Translocation ◽  
Early Response ◽  
Interferon Regulatory Factor ◽  
Immediate Early ◽  
Creb Binding Protein ◽  
Regulatory Factor ◽  
Response Element ◽  
Interferon Regulatory Factor 3

ABSTRACTInterferon establishes an antiviral state in numerous cell types through the induction of a set of immediate-early response genes. Activation of these genes is mediated by phosphorylation of latent transcription factors of the STAT family. We found that infection of primary foreskin fibroblasts with human cytomegalovirus (HCMV) causes selective transcriptional activation of the alpha/beta-interferon-responsive ISG54 gene. However, no activation or nuclear translocation of STAT proteins was detected. Activation of ISG54 occurs independent of protein synthesis but is prevented by protein tyrosine kinase inhibitors. Further analysis revealed that HCMV infection induced the DNA binding of a novel complex, tentatively called cytomegalovirus-induced interferon-stimulated response element binding factor (CIF). CIF is composed, at least in part, of the recently identified interferon regulatory factor 3 (IRF3), but it does not contain the STAT1 and STAT2 proteins that participate in the formation of interferon-stimulated gene factor 3. IRF3, which has previously been shown to possess no intrinsic transcriptional activation potential, interacts with the transcriptional coactivator CREB binding protein, but not with p300, to form CIF. Activating interferon-stimulated genes without the need for prior synthesis of interferons might provide the host cell with a potential shortcut in the activation of its antiviral defense.

scholarly journals Ipr1 Regulation by Cyclic GMP-AMP Synthase/Interferon Regulatory Factor 3 and Modulation of Irgm1 Expression via p53

2020 ◽  
Vol 40 (8) ◽  
Author(s):  
Fayang Liu ◽  
Hongni Xue ◽  
Jie Ke ◽  
Yongyan Wu ◽  
Kezhen Yao ◽  
...  
Keyword(s):  
Cyclic Gmp ◽  
Viral Infections ◽  
Pathogen Resistance ◽  
Interferon Regulatory Factor ◽  
Intracellular Pathogen ◽  
Regulatory Factor ◽  
Interferon Regulatory Factor 3 ◽  
Promoter Characterization ◽  
Ribosomal Protein L11 ◽  
Pathogenic Infection

ABSTRACT Intracellular pathogen resistance 1 (Ipr1) has been found to be a mediator to integrate cyclic GMP-AMP synthase (cGAS)–interferon regulatory factor 3 (IRF3), activated by intracellular pathogens, with the p53 pathway. Previous studies have shown the process of Ipr1 induction by various immune reactions, including intracellular bacterial and viral infections. The present study demonstrated that Ipr1 is regulated by the cGAS-IRF3 pathway during pathogenic infection. IRF3 was found to regulate Ipr1 expression by directly binding the interferon-stimulated response element motif of the Ipr1 promoter. Knockdown of Ipr1 decreased the expression of immunity-related GTPase family M member 1 (Irgm1), which plays critical roles in autophagy initiation. Irgm1 promoter characterization revealed a p53 motif in front of the transcription start site. P53 was found to participate in regulation of Irgm1 expression and IPR1-related effects on P53 stability by affecting interactions between ribosomal protein L11 (RPL11) and transformed mouse 3T3 cell double minute 2 (MDM2). Our results indicate that Ipr1 integrates cGAS-IRF3 with p53-modulated Irgm1 expression.

Interferon regulatory factor 3 in adaptive immune responses

2014 ◽  
Vol 71 (20) ◽  
pp. 3873-3883 ◽  
Author(s):  
Laure Ysebrant de Lendonck ◽  
Valerie Martinet ◽  
Stanislas Goriely
Keyword(s):  
Immune Responses ◽  
Interferon Regulatory Factor ◽  
Regulatory Factor ◽  
Adaptive Immune Responses ◽  
Interferon Regulatory Factor 3 ◽  
Adaptive Immune
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