SIKE is an IKKε/TBK1-associated suppressor of TLR3- and virus-triggered IRF-3 activation pathways

Huang, Jun; Liu, Ting; Xu, Liang‐Guo; Chen, Danying; Zhai, Zhonghe; Shu, Hong‐Bing

doi:10.1038/sj.emboj.7600863

Cited by 150 publications

(149 citation statements)

References 34 publications

Supporting

Mentioning

144

Contrasting

Unclassified

Order By: Relevance

“…Tumor-necrosis factor-a and IL-1b (R&D Systems, Minneapolis, MN, USA), mouse monoclonal antibodies against Flag and HA (Sigma, St Louis, MO, USA) and rabbit polyclonal antibodies against IRF3 and MDA5 (Santa Cruz Biotechnology, Santa Cruz, CA, USA) were purchased from the indicated manufacturers; SeV and VSV were previously described. 7,36,37 Plasmids A plasmid carrying a greater-than-unit-length (129%) HBV genome (payw1.2; subtype ayw) and the same plasmid with a stop codon replacing the coding sequence for amino acid 7 of HBx (payw*7) were previously described. 34,35 The vector pEGFP-C1 was a gift provided by Yan Wu.…”

Section: Methodsmentioning

confidence: 99%

“…Luciferase reporter plasmids for NF-kB, ISRE and the IFN-b promoters, as well as mammalian expression plasmids for HA-or Flag-tagged RIG-I, RIG-I-N, MDA5, MDA5-N, MDA5-C, VISA, TBK1, MITA and IRF3, were previously described. 7,11,36,37 Expression plasmids for human HA-, Flag-or GFP-tagged HBx and RFP-tagged RIG-I, MDA5 and VISA were constructed by standard molecular biology techniques.…”

Section: Methodsmentioning

confidence: 99%

“…Coimmunoprecipitation, immunoblot analysis, native polyacrylamide gel electrophoresis (PAGE) and VSV plaque assays 7,36,37 Coimmunoprecipitation and western blot analysis. For transient transfection and coimmunoprecipitation experiments, 293 cells (,1310 6 ) plated on 10-cm dishes were transfected with indicated plasmids for 24 h. The transfected cells were lysed in 800 ml of lysis buffer (20 mM Tris, pH 7.5, 150 mM NaCl, 1% Triton, 1 mM EDTA, 10 ml/ml aprotinin, 10 mg/ml leupeptin, 1 mM phenylmethylsulfonyl fluoride).…”

Section: Transfection and Reporter Assaysmentioning

confidence: 99%

See 2 more Smart Citations

Hepatitis B virus X protein suppresses virus-triggered IRF3 activation and IFN-β induction by disrupting the VISA-associated complex

Wang

Mao

et al. 2010

Cell Mol Immunol

View full text Add to dashboard Cite

Viral RNAs produced during viral infection are recognized by the cytoplasmic RNA helicases retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5). A central adapter protein downstream of RIG-I and MDA5 is the mitochondrial membrane protein virus-induced signaling adaptor (VISA), which mediates the induction of type I interferons (IFNs) through the activation of transcription factors such as nuclear factor-kappaB (NF-kB) and IFN-regulatory factor-3 (IRF3). Here we found that hepatitis B virus (HBV)-encoded X protein (HBx) acts as an inhibitor of virus-triggered IRF3 activation and IFN-b induction. Reporter and plaque assays indicate that HBx inhibits signaling by components upstream but not downstream of VISA. Immunoprecipitation experiments indicate that HBx interacts with VISA and disrupts the association of VISA with its upstream and downstream components. These findings suggest that HBx acts as a suppressor of virus-triggered induction of type I IFNs, which explains the observation that HBV causes transient and chronic infection in hepatocytes but fails to activate the pattern recognition receptor-mediated IFN induction pathways.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Transfection and Reporter Assaysmentioning

confidence: 99%

See 1 more Smart Citation

Hepatitis B virus X protein suppresses virus-triggered IRF3 activation and IFN-β induction by disrupting the VISA-associated complex

Wang

Mao

et al. 2010

Cell Mol Immunol

View full text Add to dashboard Cite

show abstract

“…Different mechanisms of regulation of activity of IRF3 have been reported, including positive-feedback regulation by IRF7, 21 regulation of phosphorylation and dimerization of IRF3 by Cyclophilin B, 22 negative regulation by PIN1 to facilitate the degradation of IRF3, 23 and by SIKE to disrupt interactions of IKKe or TBK1 with TRIF, RIG-I and IRF3. 24 In addition, several splicing isoforms of IRF3, such as IRF-3a (Ref. 13) and IRF3-nirs3, 25 have been identified and functioned in the negative modulation of the activity of IRF3.…”

Section: Discussionmentioning

confidence: 99%

Interferon regulatory factor 3-CL, an isoform of IRF3, antagonizes activity of IRF3

Chen

2010

Cell Mol Immunol

View full text Add to dashboard Cite

Interferon regulatory factor 3 (IRF3), one member of the IRF family, plays a central role in induction of type I interferon (IFN) and regulation of apoptosis. Controlled activity of IRF3 is essential for its functions. During reverse transcription (RT)-PCR to clone the full-length open reading frame (ORF) of IRF3, we cloned a full-length ORF encoding an isoform of IRF3, termed as IRF3-CL, and has a unique carboxyl-terminus of 125 amino acids. IRF3-CL is ubiquitously expressed in distinct cell lines. Overexpression of IRF3-CL inhibits Sendai virus (SeV)-triggered induction of IFN-b and SeV-induced and inhibitor of NF-kB kinase-e (IKKe)-mediated nuclear translocation of IRF3. When IKKe is overexpressed, IRF3-CL is associated with IRF3. These results suggest that IRF3-CL, the alternative splicing isoform of IRF-3, may function as a negative regulator of IRF3. Keywords: interferon regulatory factor 3; negative regulation; splicing variant INTRODUCTIONThe interferon regulatory factor (IRF) family of transcriptional factors plays versatile roles in many biological processes, including innate and adaptive immune responses, cell growth control, apoptosis and hematopoietic development. 1,2 To date, nine members of the mammalian IRF family have been identified and characterized, each containing a highly conserved DNA-binding domain of ,120 amino acids (aa) at the amino terminus, and a variable carboxyl-terminal IRF association domain (IAD). 2 IRF3, one member of the IRF family, possesses a transactivation domain (aa 134-394) and two autoinhibition domains. 3 After viral infection, the latent IRF3, which resides primarily in the cytoplasm, is phosphorylated by the inhibitor of NF-kB kinase-e (IKKe) and TANK-binding kinase 1 (TBK1) and forms a homo-or heterodimer with other transcriptional factors which then translocates into the nucleus. [4][5][6] The activated IRF3 associates with the transcriptional cofactors cyclic AMP-responsive elementbinding protein and P300 to bind to the specific DNA targets, thus leading to transcriptional initiation of target genes with other cofactors simultaneously recruited. 7 Accumulating evidence demonstrates that IRF3 plays an essential role in the virus-or bacterium-mediated induction of interferon (IFN)-b and a subset of IFN-stimulated genes through the Toll-like receptors or the cytosolic receptors pathway. 8-10 Furthermore, IRF3 has been shown to function as a vital signaling regulator in the innate immune response, development of immune cells and apoptosis. 11 As rapid and controlled cellular responses are pivotal to host defense, the activity of IRF3 should be regulated at multiple levels.

show abstract

“…The reporter assay was performed as described previously. 33,34 Cells (2 Â 10 5 ) were transfected with 50 ng of pGL3-p53-luc (for p53 activation), 10 ng of pGL3-TK-luc and the indicated levels of expression constructs using Lipofectamine 2000 according to the manufacturer's instructions. Luciferase activity was determined using the luciferase assay system and chemiluminescent reagents from Promega (Madison, WI, USA).…”

Section: Methodsmentioning

confidence: 99%

Nemo-like kinase is critical for p53 stabilization and function in response to DNA damage

et al. 2014

Cell Death Differ

View full text Add to dashboard Cite

The DNA damage response (DDR) acts as a protective mechanism for maintaining cell homeostasis. Nemo-like kinase (NLK) is a serine/threonine-protein kinase that has an important role in many pathways; however, its function in the DDR has not yet been defined. In our study, NLK-deficient HCT116 cells were found to be resistant to etoposide-induced cell death. We demonstrated that NLK is required for p53 activation in response to DNA damage. Remarkably, mechanistic studies revealed that NLK interacts with p53 and stabilizes p53 by blocking MDM2-mediated p53 ubiquitination and degradation. Furthermore, NLK enhances p53 activity and affects expression downstream of p53. Interestingly, these functions of NLK are not related to its kinase activity. Consistent with these results, NLK-deficient cells have a resistance effect on DNA damage. Therefore, these findings emphasize that NLK is a novel factor in DDR mechanisms.

show abstract

SIKE is an IKKε/TBK1-associated suppressor of TLR3- and virus-triggered IRF-3 activation pathways

Cited by 150 publications

References 34 publications

Hepatitis B virus X protein suppresses virus-triggered IRF3 activation and IFN-β induction by disrupting the VISA-associated complex

Hepatitis B virus X protein suppresses virus-triggered IRF3 activation and IFN-β induction by disrupting the VISA-associated complex

Interferon regulatory factor 3-CL, an isoform of IRF3, antagonizes activity of IRF3

Nemo-like kinase is critical for p53 stabilization and function in response to DNA damage

Contact Info

Product

Resources

About