Movatterモバイル変換

[0]ホーム
URL:

Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
Thehttps:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log inShow account info
Access keysNCBI HomepageMyNCBI HomepageMain ContentMain Navigation
pubmed logo
Advanced Clipboard
User Guide

Full text links

Elsevier Science full text link Elsevier Science Free PMC article
Full text links

Actions

Share

.2015 Jun 5;290(23):14729-39.
doi: 10.1074/jbc.M114.633065. Epub 2015 Apr 24.

Aryl Hydrocarbon Receptor Interacting Protein Targets IRF7 to Suppress Antiviral Signaling and the Induction of Type I Interferon

Affiliations

Aryl Hydrocarbon Receptor Interacting Protein Targets IRF7 to Suppress Antiviral Signaling and the Induction of Type I Interferon

Qinjie Zhou et al. J Biol Chem..

Abstract

The transcription factor IRF7 (interferon regulatory factor 7) is a key regulator of type I interferon and plays essential roles in restricting virus infection and spread. IRF7 activation is tightly regulated to prevent excessive inflammation and autoimmunity; however, how IRF7 is suppressed by negative regulators remains poorly understood. Here, we have identified AIP (aryl hydrocarbon receptor interacting protein) as a new binding partner of IRF7. The interaction between AIP and IRF7 is enhanced upon virus infection, and AIP potently inhibits IRF7-induced type I IFN (IFNα/β) production. Overexpression of AIP blocks virus-induced activation of IFN, whereas knockdown of AIP by siRNA potentiates virally activated IFN production. Consistently, AIP-deficient murine embryonic fibroblasts are highly resistant to virus infection because of increased production of IFNα/β. AIP inhibits IRF7 function by antagonizing the nuclear localization of IRF7. Together, our study identifies AIP as a novel inhibitor of IRF7 and a negative regulator of innate antiviral signaling.

Keywords: AIP; IRF7; antiviral signaling; type I interferon.

© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

PubMed Disclaimer

Figures

FIGURE 1.
FIGURE 1.
AIP interacts with IRF7 in a virus-inducible manner.A, 293T cells were transfected with Myc-AIP (200 ng) and/or Flag-IRF7 (500 ng) as indicated. After 24 h, cells were lysed and subjected to co-IPs and Western blotting using the indicated antibodies.B, 293T cells were transfected with Myc-AIP (200 ng) and 500 ng of Flag-IRF7 or Flag-MDA5. After 24 h, cells were infected with SeV, and lysates were subjected to co-IPs and Western blotting using the indicated antibodies.C, 293T cells were transfected with 500 ng of Flag-IRF7. After 24 h, cells were infected with SeV, and lysates were subjected to co-IPs and Western blotting using the indicated antibodies.D, schematic of AIP domains and deletion mutants.E, schematic of IRF7 domains and deletion mutants.F, 293T cells were transfected with 200 ng of wild-type AIP or AIP deletion mutants together with Flag-IRF7 (500 ng), followed by SeV infection. After 24 h, cells were lysed and subjected to co-IPs and Western blotting using the indicated antibodies.G, 293T cells were transfected with Myc-AIP (200 ng) and 500 ng of wild-type IRF7 or IRF7 deletion mutants, followed by SeV infection. After 24 h, cells were lysed and subjected to co-IPs and Western blotting using the indicated antibodies.IgG(L), immunoglobulin light chain;PPIase, peptidyl-prolylcis-trans-isomerase;IB, immunoblot;WCL, whole cell lysate.
FIGURE 2.
FIGURE 2.
AIP inhibits antiviral signaling and promotes virus infection.A–C, 293T cells were transfected with Myc-AIP (200 ng) and/or Flag-IRF7 (500 ng) together with 100 ng of IFN-β-luc (A), NF-κB-luc (B), or IFN-α4-luc (C) and pRL-TKRenilla plasmid (10 ng). After 24 h, cells were infected with SeV or treated with TNF (20 ng/ml) as indicated. Cell lysates were subjected to Dual-Luciferase assays and Western blotting using the indicated antibodies.D, 293T cells were transfected with either nontargeting control or AIP siRNAs. After 24 h, Flag-IRF7 (500 ng), IFN-α4-luc (100 ng), and pRL-TKRenilla (10 ng) plasmids were transfected followed by SeV infection. The next day, cell lysates were harvested and subjected to Dual-Luciferase assays and Western blotting using the indicated antibodies.E andF, 293T cells were transfected with either 200 ng of empty vector or Myc-AIP (E) or 20 pmol of control nontargeting siRNA or a pool of AIP siGENOME siRNAs (F), followed by infection with VSV-GFP (multiplicity of infection, 0.001). After 18 h, cells were examined by fluorescence microscopy (images taken at 10× magnification). Cell lysates were subjected to Western blotting using the indicated antibodies.G, 293T cells were transfected with 20 pmol of control siRNA or an independent single AIP siRNA (siAIP-2), followed by infection with VSV-GFP. Cell lysates were subjected to Western blotting using the indicated antibodies.IB, immunoblot.
FIGURE 3.
FIGURE 3.
Aip−/− MEFs produce elevated type I IFN and are resistant to virus infection.A,Aip−/− and wild-type MEFs were infected with VSV-GFP (multiplicity of infection, 1.0). After 18 h, cells were examined by fluorescence microscopy (images taken at 10× magnification), and lysates were subjected to Western blotting using the indicated antibodies.B,Aip−/− MEFs were transfected with 200 ng of empty vector or Myc-AIP, followed by VSV-GFP virus infection (multiplicity of infection, 1.0). The next day, the cells were subjected to fluorescence microscopy (images taken at 20× magnification), and lysates were used for Western blotting using the indicated antibodies.C andD,Aip−/− and wild-type MEFs were transfected with poly(I:C) (C; 20 μg) or infected with SeV (D; 20 HA) for the indicated times. Cell supernatants were harvested and subjected to ELISA for the detection of IFN-β and IFN-α4 as indicated.E, wild-type MEFs were transfected with Flag-IRF7 (500 ng) and/or Myc-AIP (200 ng) plasmids, followed by SeV infection. Total mRNA was extracted and subjected to quantitative real time PCR for IFN-α4 expression (upper panel), and RT-PCR for IRF7 and AIP expression (lower panels). 18S rRNA was used as the internal control in both cases.F,Aip−/− MEFs were transfected with 200 ng of empty vector or Myc-AIP, followed by SeV infection. The next day, total mRNA was extracted and subjected to quantitative real time PCR for IFN-β, IFN-α4, and IL-6 expression. Cell lysates were subjected to Western blotting using the indicated antibodies.IB, immunoblot.
FIGURE 4.
FIGURE 4.
AIP does not inhibit IRF3 and IRF7 phosphorylation.A, 293T cells were transfected with either nontargeting control or AIP siRNAs. After 24 h, cells were transfected with either empty vector (500 ng) or IRF3SA (500 ng) plasmids, together with IFN-β-luc (100 ng) and pRL-TKRenilla (10 ng), followed by SeV infection. The next day, cell lysates were harvested and subjected to Dual-Luciferase assays.B andC, 293T cells were transfected with GFP-ΔRIG-I (500 ng), Myc-AIP (200 ng), Flag-A20 (200 ng), Flag-IRF7 (500 ng), and GFP-TBK1 (500 ng) as indicated. The next day cell lysates were harvested and subjected to Western blotting using the indicated antibodies.IB, immunoblot.
FIGURE 5.
FIGURE 5.
AIP inhibits IRF7 nuclear localization and transactivation.A, 293T cells were transfected with Flag-IRF7 (500 ng) and Myc-AIP (200 ng) followed by SeV infection. After 24 h, cells were lysed and subjected to subcellular fractionation, followed by Western blotting using the indicated antibodies. Anti-LDH1 was used as a marker for the cytoplasmic compartment. Anti-poly(ADP-ribose) polymerase was used as a marker for the nuclear compartment.B andC,Aip−/− MEFs were seeded on glass coverslips overnight and transfected with Flag-IRF7 (500 ng), Flag-IRF3 (500 ng), and Myc-AIP (200 ng) as indicated, followed by SeV infection. After 18 h, cells were subjected to immunofluorescence microscopy.Green, Flag-IRF7 or IRF3;red, Myc-AIP;blue, DAPI.D, 293T cells were transfected with Gal4-IRF7 (500 ng), Myc-AIP (100/200/500 ng), and Gal4-luc (100 ng). After 24 h, cell lysates were subjected to Dual-Luciferase assays and Western blotting using the indicated antibodies.IB, immunoblot.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Hornung V., Ellegast J., Kim S., Brzózka K., Jung A., Kato H., Poeck H., Akira S., Conzelmann K. K., Schlee M., Endres S., Hartmann G. (2006) 5′-Triphosphate RNA is the ligand for RIG-I. Science 314, 994–997 - PubMed
    1. Pichlmair A., Schulz O., Tan C. P., Näslund T. I., Liljeström P., Weber F., Reis e Sousa C. (2006) RIG-I-mediated antiviral responses to single-stranded RNA bearing 5′-phosphates. Science 314, 997–1001 - PubMed
    1. Kato H., Takeuchi O., Sato S., Yoneyama M., Yamamoto M., Matsui K., Uematsu S., Jung A., Kawai T., Ishii K. J., Yamaguchi O., Otsu K., Tsujimura T., Koh C. S., Reis e Sousa C., Matsuura Y., Fujita T., Akira S. (2006) Differential roles of MDA5 and RIG-I helicases in the recognition of RNA viruses. Nature 441, 101–105 - PubMed
    1. Schoggins J. W., MacDuff D. A., Imanaka N., Gainey M. D., Shrestha B., Eitson J. L., Mar K. B., Richardson R. B., Ratushny A. V., Litvak V., Dabelic R., Manicassamy B., Aitchison J. D., Aderem A., Elliott R. M., García-Sastre A., Racaniello V., Snijder E. J., Yokoyama W. M., Diamond M. S., Virgin H. W., Rice C. M. (2014) Pan-viral specificity of IFN-induced genes reveals new roles for cGAS in innate immunity. Nature 505, 691–695 - PMC - PubMed
    1. Gack M. U., Shin Y. C., Joo C. H., Urano T., Liang C., Sun L., Takeuchi O., Akira S., Chen Z., Inoue S., Jung J. U. (2007) TRIM25 RING-finger E3 ubiquitin ligase is essential for RIG-I-mediated antiviral activity. Nature 446, 916–920 - PubMed

Publication types

MeSH terms

Substances

Related information

Grants and funding

LinkOut - more resources

Full text links
Elsevier Science full text link Elsevier Science Free PMC article
Cite
Send To

NCBI Literature Resources

MeSHPMCBookshelfDisclaimer

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

[8]ページ先頭
©2009-2025 Movatter.jp