| 2006 |
RIG-I (DDX58) is essential for type I interferon production in response to paramyxoviruses, influenza virus, and Japanese encephalitis virus in fibroblasts and conventional dendritic cells, while MDA5 is critical for picornavirus detection; RIG-I and MDA5 recognize distinct RNA virus classes in vivo. |
Gene-targeted RIG-I knockout and MDA5 knockout mice; interferon induction assays; viral challenge experiments |
Nature |
High |
16625202
|
| 2006 |
5'-triphosphate RNA (3pRNA) is the molecular ligand for RIG-I; the 5'-triphosphate end generated by viral polymerases directly binds RIG-I and activates interferon responses, whereas capping or nucleoside modification of the 5'-triphosphate abrogates detection. |
Direct binding assay (5'-triphosphate RNA to RIG-I); phosphatase sensitivity assay; genomic RNA from negative-strand RNA viruses; interferon-alpha response assays |
Science |
High |
17038590
|
| 2005 |
RIG-I is required for induction of type I interferons via IRF3 activation through IκB kinase-related kinases in fibroblasts and conventional dendritic cells after RNA virus infection; plasmacytoid DCs use the TLR system rather than RIG-I for viral detection. |
Gene-targeted RIG-I knockout mice; IFN induction assays; cell-type-specific analysis |
Immunity |
High |
16039576
|
| 2011 |
Crystal structure of RIG-I in complex with dsRNA reveals that dsRNA is sheathed within a network including helicase domains HEL1 and HEL2, an insertion domain HEL2i, and a C-terminal regulatory domain (CTD); a V-shaped pincer connects HEL2 and CTD, coupling RNA binding with ATP hydrolysis. |
X-ray crystallography of RIG-I:dsRNA complex |
Cell |
High |
22000018
|
| 2010 |
Physiological RIG-I agonists during influenza A virus or Sendai virus infection are exclusively generated by virus replication and correspond to full-length virus genomes bearing 5'-triphosphates; non-genomic viral transcripts, short replication intermediates, and cleaved self-RNA do not substantially contribute to interferon induction. |
Three orthogonal approaches (RNA immunoprecipitation, biochemical fractionation, genetic approaches) to identify RIG-I agonists in infected cells |
Cell |
High |
20144762
|
| 2015 |
DDX58 (RIG-I) mutations in ATP-binding motifs (C268F and E373A) confer constitutive RIG-I activation and cause atypical Singleton-Merten syndrome with increased interferon activity and IFN-stimulated gene expression; C268 and E373 residues are located close to ADP and RNA binding sites. |
Exome sequencing; functional assays measuring IFN activity and ISG expression; structural analysis of mutant positions; cytopathic assays in human trabecular meshwork cells |
American Journal of Human Genetics |
High |
25620203
|
| 2015 |
RIG-I CARDs must form homo-tetramers (lock-washer configuration) to interact with MAVS and nucleate MAVS filament formation, which is a prerequisite for downstream signaling; TRIM25-mediated K63-linked polyubiquitination stabilizes the 2CARD tetramer. |
Structural analysis; biochemical reconstitution of CARD oligomerization; MAVS filament formation assays |
Current Opinion in Virology |
Medium |
25942693
|
| 2018 |
K63-linked polyubiquitination of RIG-I by TRIM25 (on 2CARDs) and Riplet (on CTD) positively regulates RIG-I activation; RNF125 mediates K48-linked polyubiquitination leading to proteasomal degradation (negative regulation); CYLD removes K63-linked chains as a negative regulator. |
Ubiquitination assays; knockout/knockdown studies; domain-specific ubiquitination mapping |
Frontiers in Immunology |
High |
29354136
|
| 2019 |
NLRP12 dampens RIG-I-mediated signaling by interacting with TRIM25 (via its nucleotide-binding domain) to prevent TRIM25-mediated K63-linked ubiquitination and activation of RIG-I, and by enhancing RNF125-mediated K48-linked degradative ubiquitination of RIG-I. |
Co-immunoprecipitation; ubiquitination assays; myeloid-cell-specific Nlrp12 knockout mice; VSV infection assays |
Cell Host & Microbe |
High |
30902577
|
| 2017 |
Upon RIG-I activation, TRIM25 is redistributed into cytoplasmic dots associated with stress granules; RIG-I associates with TRIM25/stress granules and subsequently moves to mitochondrial MAVS; MAVS competes with TRIM25 for RIG-I binding, suggesting RIG-I transits from TRIM25 to MAVS at mitochondria. |
Bimolecular fluorescence complementation (BiFC); super-resolution microscopy; subcellular localization studies in virus-infected cells |
Journal of Virology |
Medium |
27807226
|
| 2010 |
SUMOylation of RIG-I by SUMO-1 enhances type I interferon production by increasing K63-linked ubiquitination of RIG-I and promoting its interaction with downstream adaptor Cardif/MAVS. |
SUMOylation assay; co-immunoprecipitation; IFN-I production assays |
Protein & Cell |
Medium |
21203974
|
| 2018 |
RIG-I uses an ATPase-powered 'kinetic proofreading' mechanism for RNA discrimination: ATP binding facilitates dsRNA engagement but makes RIG-I promiscuous; ATP hydrolysis dissociates self-RNAs faster than 5'ppp dsRNAs; RIG-I translocates directionally from dsRNA end into the stem, with the 5'ppp end throttling translocation to build signaling-active oligomeric complexes. |
Transient-state kinetics; ATPase activity assays; translocation assays; helicase motif mutagenesis |
Molecular Cell |
High |
30270105
|
| 2019 |
RIG-I is actively antagonized by RNAs containing 5'-monophosphates (5'-p RNA) through a gating mechanism: 5'-p RNA binding induces an alternative RIG-I conformation that blocks the C-terminal domain (CTD), short-circuiting signaling activation. |
Quantitative biophysical binding assays; immunological signaling assays; conformational analysis |
Cell Reports |
High |
30784585
|
| 2022 |
Cryo-EM structures of RIG-I in complex with host and viral RNA ligands show that RIG-I adopts two distinct protein folds: a high-affinity signaling-conducive conformation upon binding viral RNA (5'-triphosphate dsRNA), and an autoinhibited conformation upon binding host RNA that stimulates RNA release, explaining selective antiviral sensing. |
High-resolution cryo-EM structural determination; functional validation |
Molecular Cell |
High |
36272408
|
| 2015 |
RIG-I's selectivity for blunt-ended 5'-ppp dsRNAs is ~3000-fold higher than non-blunt-ended dsRNAs; the autoinhibitory CARD2-HEL2i interface acts as a gate that prevents cellular RNAs from generating productive signaling complexes. |
Quantitative binding and ATPase assays; CARD deletion and CARD2-HEL2i interface point mutants; selectivity measurements |
Nucleic Acids Research |
High |
26612866
|
| 2015 |
RIG-I ATPase activity promotes discrimination of self-RNA from non-self-RNA: ATPase activity promotes recycling of RIG-I from self-RNAs (which bind less stably) while non-self 5'ppp dsRNAs resist ATP-driven dissociation; two ribonucleotides at positions 2 and 5 on the bottom strand are minimally required for ATPase stimulation. |
In vitro ATPase assays; RNA binding assays; chimeric ribo/deoxyribonucleotide duplexes; IFN-β reporter assays |
mBio |
High |
25736886
|
| 2018 |
RIG-I Singleton-Merten syndrome variant C268F (in the ATP-binding P-loop) activates signaling independently of ATP but remains RNA-dependent; crystal structure of RIG-I C268F:dsRNA complex shows the mutation induces a structural conformation similar to that induced by ATP, explaining gain-of-function through mimicking the ATP-bound state. |
Crystal structure of RIG-I C268F:dsRNA complex; functional signaling assays; ATP-independence experiments |
eLife |
High |
30047865
|
| 2022 |
Ufmylation promotes RIG-I signaling: UFL1 (E3 ligase for ufmylation) is recruited to 14-3-3ε at ER-mitochondrial contact sites following RNA virus infection; 14-3-3ε undergoes UFM1 conjugation upon RIG-I activation; loss of ufmylation prevents 14-3-3ε interaction with RIG-I and abrogates RIG-I-MAVS interaction and IFN induction. |
Protein interaction assays (co-IP); UFM1 conjugation assays; genetic loss-of-function of ufmylation pathway; IFN induction assays |
PNAS |
Medium |
35394863
|
| 2021 |
RIG-I is recruited to DNA double-strand breaks (DSBs) and suppresses non-homologous end joining (NHEJ) by interacting with XRCC4 and impeding XRCC4/LIG4/XLF complex formation; conversely, XRCC4 promotes RIG-I signaling by enhancing RIG-I oligomerization and ubiquitination. |
Co-immunoprecipitation; DSB recruitment assays; NHEJ repair assays; RIG-I KO and overexpression; in vivo influenza virus infection in XRCC4-silenced mice |
Nature Communications |
Medium |
33846346
|
| 2018 |
Short triphosphorylated stem-loop RNAs (SLRs, 10-14 bp) specifically activate RIG-I in vivo in mice, inducing type I interferons and ISGs; SLRs demonstrate that RIG-I forms active signaling complexes without oligomerizing on RNA (short length precludes oligomerization). |
In vivo RNA delivery to mice; RNA sequencing for genome-wide expression; comparison with poly(I:C) which activates multiple sensors |
Science Advances |
High |
29492454
|
| 2019 |
MARCH5 (mitochondrial E3 ubiquitin ligase) degrades active RIG-I oligomers via K48-linked polyubiquitination at Lys193 and Lys203 residues of RIG-I; the RING domain of MARCH5 binds to the CARD domain of RIG-I; inactive phosphomimetic RIG-I (S8E) is resistant to MARCH5-mediated degradation. |
In vivo ubiquitination assay; co-immunoprecipitation; site-directed mutagenesis; MARCH5 RING domain deletion |
Cellular Signalling |
Medium |
31881323
|
| 2018 |
RIG-I recognizes the 5' region of Dengue virus and Zika virus genomes; affinity purification combined with NGS revealed the 5' end of the DENV genome bearing 5'-triphosphates as the RIG-I ligand during infection. |
Affinity purification of RIG-I:RNA complexes; next-generation sequencing; in vitro RNA production and stimulation assays |
Cell Reports |
High |
29996094
|
| 2018 |
Nuclear-resident RIG-I senses influenza A virus nuclear replication and cooperates with cytoplasmic RIG-I to induce type I interferon; nuclear RIG-I signals through the canonical RIG-I axis but cannot sense cytoplasmic-replicating Sendai virus, demonstrating compartment-specific sensing. |
Live-cell imaging; subcellular fractionation; nuclear RIG-I identification; IAV and SeV infection assays; HBV pregenomic RNA sensing |
Nature Communications |
Medium |
30097581
|
| 2022 |
RIG-I rapidly and efficiently signals from the constitutively expressed resident pool of receptors without mass aggregation at the mitochondrial membrane; interferon-induced RIG-I protein becomes embedded in cytosolic aggregates that are functionally unrelated to signaling. |
Live-cell imaging of RIG-I following dsRNA stimulation; kinetic analysis of signaling complex formation |
Molecular Cell |
Medium |
36521492
|
| 2020 |
N6-methyladenosine (m6A) modification of viral RNA enables HMPV to escape RIG-I recognition; m6A-deficient virion RNA binds more efficiently to RIG-I, facilitates RIG-I conformational change, and induces higher RIG-I expression and interferon production in a RIG-I-dependent (not MDA5-dependent) manner. |
Recombinant HMPV with m6A site mutations; RNA pulldown/binding assays; conformational assays; RIG-I KO cell lines; in vivo cotton rat infection |
Nature Microbiology |
High |
32015498
|
| 2019 |
USP14 deubiquitinates K63-linked polyubiquitin chains from RIG-I, negatively regulating antiviral responses; USP14 directly interacts with RIG-I and its knockdown enhances RIG-I-triggered type I IFN signaling. |
Co-immunoprecipitation; in vitro deubiquitination assay; siRNA knockdown; USP14-specific inhibitor (IU1) in vitro and in vivo |
European Journal of Immunology |
Medium |
30466171
|
| 2020 |
USP27X removes K63-linked polyubiquitin chains from RIG-I in a deubiquitinase-dependent manner to negatively regulate RIG-I-mediated antiviral signaling. |
siRNA library screening; co-immunoprecipitation; deubiquitination assays; overexpression and knockdown of USP27X |
PLoS Pathogens |
Medium |
32027733
|
| 2019 |
LRRC59 positively regulates RIG-I (DDX58) signaling by interacting with ISG15-associated RIG-I and blocking its association with LRRC25 (the secondary receptor that delivers RIG-I to autophagosomes for SQSTM1/p62-dependent degradation), thereby preventing autophagic degradation of RIG-I. |
Co-immunoprecipitation; autophagy flux assays; KO cells; IFN signaling measurements |
Autophagy |
Medium |
31068071
|
| 2017 |
Zyxin stabilizes physical interactions between RIG-I (and MDA5) and MAVS, functioning as a scaffold; zyxin co-immunoprecipitates with MAVS and co-localizes on mitochondria; ZYX knockdown abolishes RLR-MAVS interactions and attenuates IFN-β production. |
Yeast two-hybrid screening; co-immunoprecipitation; proximity ligation assay; ZYX knockdown with IFN-β reporter; influenza A virus RNA stimulation |
Scientific Reports |
Medium |
28928438
|
| 2021 |
IFI16 binds to influenza viral RNA via its HINa domain and to RIG-I protein via its PYRIN domain, promoting IAV-induced K63-linked polyubiquitination and RIG-I activation; IFI16 also upregulates RIG-I transcription by directly binding to and recruiting RNA polymerase II to the RIG-I promoter. |
IFI16 KO cells and p204-deficient mice; domain-specific binding assays; K63 ubiquitination assay; RNA Pol II ChIP; IFN-I production assays |
Nature Microbiology |
High |
33986530
|
| 2022 |
JMJD4 demethylates RIG-I at constitutively methylated residues K18 and K146; demethylated RIG-I suppresses IL-6-STAT3 signaling; methylated RIG-I associates with AMPKα to inhibit HMGCR phosphorylation, promoting HMGCR enzymatic activity and cholesterol synthesis. |
Mass spectrometry identification of methylation sites; hepatocyte-specific RIG-I KO mice; specific antibodies against methylated lysine sites; RIG-I lysine mutant mice; functional signaling assays |
Journal of Hematology & Oncology |
Medium |
36333807
|
| 2021 |
Novel DDX58 variant R109C is a gain-of-function mutation causing lupus nephritis through reduced RIG-I autoinhibition, leading to RIG-I hyperactivation, increased K63 ubiquitination, and MAVS aggregation; JAK inhibitor therapy suppressed the elevated IFN signature. |
Whole-exome sequencing; biochemical IFN signaling assays; K63 ubiquitination assay; MAVS aggregation assay; single-cell RNA sequencing |
JASN |
Medium |
36261300
|
| 2020 |
DUSP11 (RNA triphosphatase) removes 5'-triphosphates from both host and virus-derived RNAs, rendering them less active in inducing RIG-I-mediated immune responses; DUSP11 deficiency results in higher proportions of triphosphorylated viral transcripts, enhanced RIG-I activation, and attenuated virus replication rescued by RIG-I knockdown. |
DUSP11 knockdown/KO cells and mice; viral triphosphate RNA profiling; RIG-I activation assays; genetic rescue experiments |
Genes & Development |
High |
33184222
|
| 2023 |
CD97 negatively regulates RIG-I by upregulating RNF125 expression, which induces RNF125-mediated K48-linked ubiquitination of RIG-I at Lys181, leading to proteasomal degradation of RIG-I and suppression of IFN-I signaling. |
Co-immunoprecipitation; ubiquitination site mutagenesis; CD97-deficient mice; IFN-I signaling assays; VSV and SARS-CoV-2 replication assays |
Cellular & Molecular Immunology |
Medium |
37978243
|
| 2023 |
RIG-I competes with SPOP to bind PD-L1, attenuating polyubiquitination and proteasomal degradation of PD-L1, thereby promoting PD-L1 stability and colon cancer immune evasion independently of type I interferon stimulation. |
Co-immunoprecipitation; ubiquitination assays; RIG-I knockdown/overexpression; in vivo tumor models |
Journal for Immunotherapy of Cancer |
Medium |
37758653
|
| 2012 |
ATP and dsRNA binding triggers dimerization of RIG-I with conformational rearrangements exposing the tandem CARD domains; full-length RIG-I forms a 2:2 complex with dsRNA; phosphorylation-mimicking mutants S8E and T170E impair RIG-I binding to TRIM25, unanchored K63-linked polyubiquitin, and MAVS. |
Electron microscopy of RIG-I:dsRNA complex; co-immunoprecipitation; biochemical binding assays; phosphomimetic mutagenesis |
Protein & Cell |
Medium |
23264040
|
| 2023 |
RIG-I recognizes metabolite-capped RNAs (NAD+, FAD, dephosphoCoA caps) as signaling ligands; these RNAs have high affinity for RIG-I, stimulate ATPase activity comparably to 5'ppp dsRNA, and activate innate antiviral signaling in cells. |
In vitro transcription with metabolite initiators; ATPase activity assays; binding assays; cellular IFN signaling assays |
Nucleic Acids Research |
Medium |
37326006
|
| 2023 |
RIG-I bound to long dsRNA (>500 bp) with slow kinetics, forming stable complexes that did not dissociate; short dsRNA (<500 bp) formed complexes that dissociated efficiently in an ATP hydrolysis-dependent manner; dissociated RIG-I underwent homo-oligomerization acquiring ability to associate with MAVS, explaining length-dependent signaling. |
Binding kinetics assays; ATP hydrolysis assays; RIG-I oligomerization assays; MAVS association assays; biological activity in living cells |
Scientific Reports |
Medium |
37072508
|
| 2022 |
SMS-associated RIG-I mutations (E510V and Q517H) cause a loosened latch-gate engagement in apo RIG-I (in the HEL2i domain), dampening ATPase activity and impairing self-RNA (Cap2 moiety) proofreading, leading to increased immune activation. |
Hydrogen/deuterium exchange mass spectrometry (HDX-MS); single molecule magnetic tweezers (MT); ATPase assays; RNA proofreading assays |
Nucleic Acids Research |
High |
35580046
|