Structural basis for ubiquitin-mediated antiviral signal activation by RIG-I
- PMID: 24590070
- PMCID: PMC6136653
- DOI: 10.1038/nature13140
Structural basis for ubiquitin-mediated antiviral signal activation by RIG-I
Abstract
Ubiquitin (Ub) has important roles in a wide range of intracellular signalling pathways. In the conventional view, ubiquitin alters the signalling activity of the target protein through covalent modification, but accumulating evidence points to the emerging role of non-covalent interaction between ubiquitin and the target. In the innate immune signalling pathway of a viral RNA sensor, RIG-I, both covalent and non-covalent interactions with K63-linked ubiquitin chains (K63-Ubn) were shown to occur in its signalling domain, a tandem caspase activation and recruitment domain (hereafter referred to as 2CARD). Non-covalent binding of K63-Ubn to 2CARD induces its tetramer formation, a requirement for downstream signal activation. Here we report the crystal structure of the tetramer of human RIG-I 2CARD bound by three chains of K63-Ub2. 2CARD assembles into a helical tetramer resembling a 'lock-washer', in which the tetrameric surface serves as a signalling platform for recruitment and activation of the downstream signalling molecule, MAVS. Ubiquitin chains are bound along the outer rim of the helical trajectory, bridging adjacent subunits of 2CARD and stabilizing the 2CARD tetramer. The combination of structural and functional analyses reveals that binding avidity dictates the K63-linkage and chain-length specificity of 2CARD, and that covalent ubiquitin conjugation of 2CARD further stabilizes the Ub-2CARD interaction and thus the 2CARD tetramer. Our work provides unique insights into the novel types of ubiquitin-mediated signal-activation mechanism, and previously unexpected synergism between the covalent and non-covalent ubiquitin interaction modes.
Conflict of interest statement
The authors declare no competing financial interests.
Figures
![Extended Data Figure 1](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f5.gif)
![Extended Data Figure 2](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f6.gif)
![Extended Data Figure 3](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f7.gif)
![Extended Data Figure 4](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f8.gif)
![Extended Data Figure 5](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f9.gif)
![Extended Data Figure 6](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f10.gif)
![Extended Data Figure 7](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f11.gif)
![Extended Data Figure 8](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f12.gif)
![Extended Data Figure 9](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f13.gif)
![Figure 1](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f1.gif)
![Figure 2](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f2.gif)
![Figure 3](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f3.gif)
![Figure 4](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/6136653/bin/nihms984140f4.gif)
Comment in
-
The lock-washer: a reconciliation of the RIG-I activation models.Cell Res. 2014 Jun;24(6):645-6. doi: 10.1038/cr.2014.58. Epub 2014 May 6. Cell Res. 2014. PMID: 24797430 Free PMC article.
Similar articles
-
Oligomerization of RIG-I and MDA5 2CARD domains.Protein Sci. 2020 Feb;29(2):521-526. doi: 10.1002/pro.3776. Epub 2019 Nov 20. Protein Sci. 2020. PMID: 31697400 Free PMC article.
-
Regulation of RIG-I Activation by K63-Linked Polyubiquitination.Front Immunol. 2018 Jan 5;8:1942. doi: 10.3389/fimmu.2017.01942. eCollection 2017. Front Immunol. 2018. PMID: 29354136 Free PMC article. Review.
-
How RIG-I like receptors activate MAVS.Curr Opin Virol. 2015 Jun;12:91-8. doi: 10.1016/j.coviro.2015.04.004. Epub 2015 May 13. Curr Opin Virol. 2015. PMID: 25942693 Free PMC article. Review.
-
Molecular imprinting as a signal-activation mechanism of the viral RNA sensor RIG-I.Mol Cell. 2014 Aug 21;55(4):511-23. doi: 10.1016/j.molcel.2014.06.010. Epub 2014 Jul 10. Mol Cell. 2014. PMID: 25018021 Free PMC article.
-
The lock-washer: a reconciliation of the RIG-I activation models.Cell Res. 2014 Jun;24(6):645-6. doi: 10.1038/cr.2014.58. Epub 2014 May 6. Cell Res. 2014. PMID: 24797430 Free PMC article.
Cited by
-
TRIM38 Induced in Respiratory Syncytial Virus-infected Cells Downregulates Type I Interferon Expression by Competing with TRIM25 to Bind RIG-I.Inflammation. 2024 Apr 17. doi: 10.1007/s10753-024-01979-7. Online ahead of print. Inflammation. 2024. PMID: 38630167
-
Inhibition of the RLR signaling pathway by SARS-CoV-2 ORF7b is mediated by MAVS and abrogated by ORF7b-homologous interfering peptide.J Virol. 2024 May 14;98(5):e0157323. doi: 10.1128/jvi.01573-23. Epub 2024 Apr 4. J Virol. 2024. PMID: 38572974
-
DDX4 enhances antiviral activity of type I interferon by disrupting interaction of USP7/SOCS1 and promoting degradation of SOCS1.mBio. 2024 Mar 13;15(3):e0321323. doi: 10.1128/mbio.03213-23. Epub 2024 Feb 20. mBio. 2024. PMID: 38376239 Free PMC article.
-
Identification of pigeon mitochondrial antiviral signaling protein (MAVS) and its role in antiviral innate immunity.Arch Virol. 2024 Jan 12;169(2):26. doi: 10.1007/s00705-023-05920-5. Arch Virol. 2024. PMID: 38214770
-
SARS-CoV-2 Nsp8 suppresses MDA5 antiviral immune responses by impairing TRIM4-mediated K63-linked polyubiquitination.PLoS Pathog. 2023 Nov 13;19(11):e1011792. doi: 10.1371/journal.ppat.1011792. eCollection 2023 Nov. PLoS Pathog. 2023. PMID: 37956198 Free PMC article.
References
-
- Gack MU, et al. TRIM25 RING-finger E3 ubiquitin ligase is essential for RIG-I-mediated antiviral activity. Nature. 2007;446:916–920. - PubMed
-
- Kato H, Takahasi K, Fujita T. RIG-I-like receptors: cytoplasmic sensors for non-self RNA. Immunol Rev. 2011;243:91–98. - PubMed
-
- Kowalinski E, et al. Structural basis for the activation of innate immune pattern-recognition receptor RIG-I by viral RNA. Cell. 2011;147:423–435. - PubMed
Publication types
MeSH terms
Substances
Associated data
- Actions
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Molecular Biology Databases
Miscellaneous