| 2010 |
IFI16 directly associates with IFN-β-inducing viral DNA motifs and acts as an intracellular DNA sensor that mediates IFN-β induction; after DNA stimulation, STING is recruited to IFI16, and knockdown of IFI16 or its mouse ortholog p204 inhibits IRF3 and NF-κB activation induced by DNA and HSV-1. |
RNA interference knockdown, co-immunoprecipitation, DNA-binding assays, IRF3/NF-κB activation assays |
Nature immunology |
High |
20890285
|
| 2012 |
Crystal structures of IFI16 HIN domains in complex with dsDNA reveal that non-sequence-specific DNA recognition is accomplished through electrostatic attraction between positively charged HIN domain residues and the dsDNA sugar-phosphate backbone; an autoinhibited intramolecular AIM2 Pyrin-HIN complex is liberated by DNA binding. |
X-ray crystallography, structural analysis of HIN-DNA complexes |
Immunity |
High |
22483801
|
| 2012 |
IFI16 is predominantly nuclear, detects HSV-1 DNA primarily in the nucleus requiring a functional nuclear localization signal (NLS), and mediates IFN-β induction in a localization-dependent manner. Acetylation of the NLS by acetyltransferase p300 inhibits nuclear import and promotes cytoplasmic localization of IFI16. |
FISH, immunopurification, mutagenesis of NLS, nuclear import assays, combinatorial mass spectrometry for acetylation/phosphorylation sites, deacetylase inhibition |
Proceedings of the National Academy of Sciences of the United States of America |
High |
22691496
|
| 2012 |
HSV-1 ICP0, an E3 ubiquitin ligase expressed in the nucleus, causes nuclear relocalization and proteasomal degradation of IFI16, thereby inhibiting IFI16-dependent IRF-3 signaling. Nuclear IFI16 senses HSV-1 DNA upon its release from incoming capsids, and an unknown factor must be exported from the nucleus to activate IRF-3 through cytoplasmic STING. |
siRNA knockdown, inhibition of viral DNA release, immunofluorescence localization, infection with ICP0-expressing virus |
Proceedings of the National Academy of Sciences of the United States of America |
High |
23027953
|
| 2012 |
IFI16 acts as a restriction factor for HCMV replication by blocking Sp1-like factor binding to the HCMV DNA polymerase (UL54) promoter via an inverted repeat element (IR-1), as demonstrated by EMSA and chromatin immunoprecipitation; a dominant-negative IFI16 lacking the PYRIN domain enhanced HCMV replication. |
siRNA knockdown, dominant-negative overexpression, EMSA, ChIP, luciferase reporter with deleted/mutated promoter constructs |
PLoS pathogens |
High |
22291595
|
| 2013 |
IFI16 cooperatively assembles into filaments on dsDNA in a length-dependent manner; the pyrin domain (not the HIN DNA-binding domains) drives cooperative filament assembly, while isolated HIN domains engage dsDNA without forming filaments and with weak affinity. |
Quantitative dsDNA binding assays, electron microscopy, domain deletion/isolation experiments |
Proceedings of the National Academy of Sciences of the United States of America |
High |
24367117
|
| 2013 |
The HCMV tegument protein pUL83 inhibits IFI16-mediated nuclear DNA sensing by interacting with the IFI16 pyrin domain, blocking IFI16 oligomerization upon DNA sensing. pUL83 uses a conserved N-terminal pyrin association domain (PAD) to bind IFI16, and phosphorylation of pUL83's N-terminal domain modulates this inhibition. |
Co-immunoprecipitation, binding domain mapping, mutagenesis, oligomerization assays, cytokine expression assays |
Cell host & microbe |
High |
24237704
|
| 2013 |
IFI16 is required for pyroptotic death of CD4 T cells abortively infected with HIV; cytosolic incomplete HIV reverse transcripts are sensed by IFI16, triggering caspase-1 activation and pyroptosis. |
Unbiased proteomics, targeted biochemical approaches, lentiviral shRNA knockdown in primary CD4 T cells, caspase-1 activation assay |
Science (New York, N.Y.) |
High |
24356113
|
| 2013 |
IFI16 senses ssDNA forms produced during lentiviral replication (including HIV-1 proviral ssDNA) in human macrophages, directly binds immunostimulatory DNA, and activates the STING-TBK1-IRF3/7 pathway; IFI16 knockdown augmented lentiviral transduction and HIV-1 replication. |
Direct DNA binding assay, siRNA knockdown, colocalization/co-immunoprecipitation of IFI16 with lentiviral DNA, IFN induction assays |
Proceedings of the National Academy of Sciences of the United States of America |
High |
24154727
|
| 2013 |
During HSV-1 infection, nuclear IFI16 recognizes viral genomes and relocates to form an IFI16-ASC-procaspase-1 inflammasome in the cytoplasm, leading to IL-1β production. Independently, IFI16 interacts with cytoplasmic STING to induce IFN-β production via IRF-3 phosphorylation. HSV-1 targets IFI16 for proteasomal degradation via ICP0 at later times post-infection. |
Immunofluorescence colocalization, co-immunoprecipitation, inflammasome activation assays, IL-1β secretion, IFN-β assays, Western blotting of ICP0-dependent degradation |
Journal of virology |
High |
23427152
|
| 2014 |
IFI16 and cGAS are both required for IFN production during HSV-1 infection in human fibroblasts; cGAS is partially nuclear and interacts with IFI16, promoting IFI16 protein stability rather than primarily producing cGAMP in infected cells. |
siRNA depletion of IFI16 and cGAS, co-immunoprecipitation, cGAMP measurement, IFI16 stability assays, viral DNA association assays |
Proceedings of the National Academy of Sciences of the United States of America |
High |
25831530
|
| 2014 |
IFI16-dependent IFNβ expression during Listeria monocytogenes infection in human macrophages is triggered by bacterial DNA (not cyclic-di-AMP) via a pathway requiring both IFI16 and cGAS as well as STING. |
siRNA knockdown of IFI16, cGAS, and STING; IFNβ induction assays; stimulation with bacterial DNA vs. cyclic-di-AMP |
The EMBO journal |
Medium |
24970844
|
| 2015 |
Recognition of herpesviral genomes in the nucleus by IFI16 leads to its interaction with histone acetyltransferase p300 and IFI16 acetylation, resulting in IFI16-ASC inflammasome assembly, increased interaction with Ran-GTPase, cytoplasmic redistribution, caspase-1 activation, IL-1β production, and IFI16-STING interaction leading to IFN-β production. Acetylation is not required for sensing viral genomes but is required for downstream responses. |
Co-immunoprecipitation, proximity ligation microscopy, ChIP, acetylation inhibition, siRNA knockdown of ASC/STING, caspase-1 and IL-1β assays, IRF-3 phosphorylation assays |
PLoS pathogens |
High |
26134128
|
| 2015 |
BRCA1 forms a complex with IFI16 in the nucleus that is required for IFI16's association with viral genomes; absence of BRCA1 abrogates IFI16-viral genome association, inflammasome assembly, cytoplasmic localization, caspase-1/IL-1β production, and IFI16-STING interaction and IFN-β production during herpesviral infection. |
Co-immunoprecipitation, proximity ligation assay, siRNA knockdown of BRCA1, inflammasome and IFN-β assays, de novo viral infection models |
PLoS pathogens |
High |
26121674
|
| 2015 |
IFI16 restricts HPV18 replication through epigenetic modifications: IFI16 promotes deposition of heterochromatin marks (H3K9me2/me3) and reduction of euchromatin marks on viral chromatin at both early and late HPV18 promoters, thereby reducing viral replication and transcription. |
siRNA knockdown, AdV-IFI16 overexpression, viral load measurement, viral gene expression analysis, ChIP for histone marks |
Journal of virology |
High |
25972554
|
| 2015 |
IFI16 interacts with histone H2B in the nucleus; herpesviral genome sensing by an IFI16-H2B-BRCA1 complex triggers p300-dependent acetylation of both H2B and IFI16, Ran-GTP-mediated cytoplasmic translocation of this complex, and subsequent interaction with cGAS and STING leading to TBK1/IRF3 phosphorylation and IFN-β production. A separate IFI16-BRCA1-ASC-procaspase-1 complex mediates inflammasome/IL-1β responses. |
Mass spectrometry, co-immunoprecipitation, proximity ligation microscopy, EdU-labeled virus genome ChIP, siRNA knockdown of H2B/cGAS/STING/ASC |
PLoS pathogens |
High |
27764250
|
| 2015 |
Crystal structure of IFI16 HINa domain in complex with DNA at 2.55 Å reveals two OB folds with a unique DNA-binding surface; HINa uses loop L45 of the OB2 fold to bind to the DNA backbone, recognizing dsDNA as two single strands. Deletion of HINb compromises IFN-β induction, while HINa mutants impaired in DNA binding enhance IFN-β production. |
X-ray crystallography, domain deletion/mutagenesis, IFN-β induction assays |
Journal of molecular cell biology |
High |
26246511
|
| 2016 |
IFI16 maintains KSHV latency by binding to lytic gene promoters and acting as a transcriptional repressor; IFI16 knockdown induces KSHV lytic reactivation. During lytic cycle, IFI16 is polyubiquitinated and degraded via the proteasomal pathway by a late lytic KSHV gene product. |
siRNA knockdown, IFI16 overexpression, ChIP of KSHV promoters, luciferase reporter assays, ubiquitination assays, phosphonoacetic acid blockade of DNA replication |
Journal of virology |
High |
27466416
|
| 2017 |
In human keratinocytes, IFI16 cooperates with cGAS during DNA sensing; both are required for full innate immune activation. IFI16 is required for cGAMP-induced activation of STING, and interacts with STING to promote STING phosphorylation and translocation. |
siRNA knockdown of cGAS and IFI16, cGAMP stimulation, co-immunoprecipitation of IFI16-STING, STING phosphorylation and translocation assays |
Nature communications |
High |
28194029
|
| 2017 |
In human macrophages, IFI16 functions at two levels in the cGAS-STING pathway: IFI16 depletion impairs cGAMP production upon DNA stimulation (acting upstream of or alongside cGAS), and IFI16 is vital for downstream STING signaling by facilitating recruitment and activation of TBK1 in the STING complex. |
siRNA depletion, cGAMP measurement, TBK1 recruitment assays, IFI16 overexpression with cGAS |
Nature communications |
High |
28186168
|
| 2018 |
IFI16, together with DNA damage response factors ATM and PARP-1, mediates non-canonical STING activation (independent of cGAS) following nuclear DNA damage; this results in assembly of an alternative STING signaling complex including p53 and the E3 ubiquitin ligase TRAF6. TRAF6 catalyzes K63-linked ubiquitin chains on STING, activating NF-κB. |
Co-immunoprecipitation, siRNA knockdown of IFI16/ATM/PARP-1/cGAS, ubiquitination assays, NF-κB activation assays, gene expression analysis |
Molecular cell |
High |
30193098
|
| 2019 |
IFI16 restricts HIV-1 independently of immune DNA sensing by binding and inhibiting the host transcription factor Sp1 that drives viral gene expression; this activity requires the N-terminal pyrin domain and nuclear localization, but not the HIN domains. IFI16 also inhibits LINE-1 retrotransposition in a Sp1-dependent manner. |
IFI16-Sp1 binding assays, pyrin domain and HIN domain mutants, HIV-1 transcription assays, HIV-1 latency reactivation assays, LINE-1 retrotransposition assay |
Cell host & microbe |
High |
31175045
|
| 2019 |
STING directly interacts with IFI16 and facilitates IFI16 degradation via the ubiquitin-proteasome pathway by recruiting E3 ligase TRIM21; the pyrin region of IFI16 mediates the IFI16-STING interaction, and lysines K3/4/6 in the N-terminal region of IFI16 are key ubiquitination sites. IFI16-K3/4/6R mutant resistant to degradation shows enhanced IFN-β and antiviral gene expression. |
Co-immunoprecipitation, ubiquitination assays, domain mapping, IFI16 degradation-resistant mutant (K3/4/6R), IFN-β induction assays, HSV-1 infection |
Cell reports |
High |
31665637
|
| 2019 |
IFI16 is in complex with H3K9 methyltransferases SUV39H1 and GLP; IFI16 recruits them to the KSHV genome during de novo infection and latency, resulting in H3K9me2/me3 deposition that serves as a docking site for HP1α, leading to epigenetic silencing of KSHV lytic genes. |
Co-immunoprecipitation of IFI16 with SUV39H1 and GLP, ChIP for H3K9me2/me3 and HP1α on KSHV genome, IFI16 knockdown |
eLife |
High |
31682228
|
| 2019 |
IFI16 oligomerization is mediated by charge-dependent interactions at specific pyrin domain residues; oligomerization is necessary for IFI16 assembly onto parental HSV-1 viral genomes at the nuclear periphery, for antiviral cytokine induction, suppression of viral proteins, and restriction of viral progeny. Oligomerization promotes interactions with transcriptional regulatory proteins including PAF1C, UBTF, and ND10 bodies. |
Structural modeling, mutagenesis of oligomerization-deficient PYD residues, charge mimics, immunoaffinity purification, targeted mass spectrometry, CRISPR/Cas9, confocal microscopy |
mBio |
High |
31337724
|
| 2019 |
IFI16 forms filamentous nuclear structures on viral DNA within HSV-1 replication compartments; these filaments recruit PML, Sp100, and ATRX as co-restriction factors and reduce elongation-competent RNA Pol II in replication compartments, constituting a nuclear 'restrictosome' that silences progeny viral DNA. |
Structured illumination microscopy, immunofluorescence, correlation of filament formation with restriction efficiency, RNA Pol II ChIP-like assays |
mBio |
Medium |
30670617
|
| 2021 |
IFI16 directly binds influenza viral RNA via its HINa domain and interacts with RIG-I protein via its PYRIN domain, promoting K63-linked polyubiquitination and RIG-I activation. IFI16 also positively upregulates RIG-I transcription by direct binding to and recruitment of RNA polymerase II to the RIG-I promoter. |
IFI16 knockout cells, p204-deficient mice, RNA binding assays with HINa domain, co-immunoprecipitation of IFI16-RIG-I, RIG-I ubiquitination assays, ChIP for RNA Pol II at RIG-I promoter |
Nature microbiology |
High |
33986530
|
| 2021 |
IFI16 accumulates at double-strand break (DSB) sites where it inhibits recruitment of DNA damage response (DDR) factors, increases cytoplasmic DNA fragment release, and induces STING-mediated type I IFN production; IFI16 depletion reduces doxorubicin-induced STING signaling and antitumor immunity in TNBC. |
IFI16 depletion, immunofluorescence at DSB sites, DDR factor recruitment assays, cytoplasmic DNA quantification, STING pathway activation assays, in vivo tumor model |
Cell reports |
Medium |
34936865
|
| 2021 |
IFI16 undergoes phase separation (liquid-liquid phase separation, LLPS) nucleated by viral DNA binding; multiple phosphorylation sites within an intrinsically disordered region (IDR), regulated by CDK2 and GSK3β, act combinatorially to activate IFI16 LLPS and facilitate filamentation. IDR phosphorylation provides a toggle between active and inactive IFI16, decoupling cytokine expression from repression of viral transcription. |
In vitro LLPS reconstitution, in vivo LLPS assays, phosphorylation site mutagenesis, CDK2/GSK3β kinase assays, HSV-1 infection models, cytokine and viral transcription readouts |
Nucleic acids research |
High |
37283074
|
| 2021 |
DNA-dependent protein kinase (DNA-PK) is recruited to IFI16 at incoming viral DNA at the nuclear periphery during HSV-1 infection; DNA-PK phosphorylates IFI16 at T149, and this phosphorylation promotes IFI16-driven cytokine responses. |
Thermal proximity coaggregation (TPCA) mass spectrometry, time-resolved PPI mapping, IFI16 T149 phosphorylation validation, cytokine response assays upon DNA damage and viral infection |
Science advances |
High |
34144993
|
| 2022 |
IFI16 interacts with KAP1 (KRAB-associated protein 1) and the site-specific DNA binding KRAB-ZFP SZF1 to form a partnership with the constitutive heterochromatin machinery; this complex silences the EBV lytic switch protein ZEBRA (BZLF1 gene) and contributes to H3K9 trimethylation at EBV lytic genes, maintaining EBV latency. |
Co-immunoprecipitation of IFI16-KAP1-SZF1, ChIP for IFI16 and KAP1 at BZLF1 promoter, H3K9me3 ChIP, IFI16 knockdown with lytic gene induction readouts |
Journal of virology |
High |
35969079
|
| 2022 |
IFI16 binds the HSV-1 genome in a sequence-independent manner with broad enrichment at UL30 (viral DNA polymerase) and US1-US7 loci; IFI16 binding globally induces chromatinization (reduced accessibility) of HSV-1 DNA genome and decreases global HSV-1 protein expression. |
ChIP-seq, ATAC-seq, parallel reaction monitoring mass spectrometry of viral proteins, IFI16 knockout cells |
mSystems |
High |
35575489
|
| 2003 |
IFI16 interacts with BRCA1 (aa 502–802) through its Pyrin domain (aa 1–130); coexpression of IFI16 and BRCA1 enhanced DNA damage-induced apoptosis in mouse embryonic fibroblasts, and a mutant IFI16 deficient in BRCA1 binding did not induce apoptosis. IFI16 is localized in the nucleoplasm and nucleoli, and BRCA1 is required for its nucleolar localization following ionizing radiation. |
Co-immunoprecipitation, domain mapping, apoptosis assays, adenovirus-mediated expression, immunocytochemistry |
Oncogene |
Medium |
14654789
|
| 2003 |
siRNA-mediated reduction of IFI16 expression induces p21Waf1 mRNA and protein through p53 activation and causes cell cycle arrest with reduced phosphorylated Rb; IFI16 negatively regulates p53 protein stability and transcriptional activity at the p21 promoter in normally growing cells. |
siRNA knockdown, p21 expression assays, promoter-reporter assays, cell cycle analysis, Rb phosphorylation |
The Journal of biological chemistry |
Medium |
12925527
|
| 2008 |
The IFI16 HIN200 domain has RPA-like OB-fold nucleic acid binding properties: it binds ssDNA with higher affinity than dsDNA, recognizes ssDNA in the same orientation as RPA, oligomerizes upon ssDNA binding, wraps and stretches ssDNA, but does not destabilize dsDNA. |
Structural modeling (fold recognition), biophysical binding assays, ssDNA orientation assays, oligomerization assays |
Biochimica et biophysica acta |
Medium |
18472023
|
| 2011 |
Increased IFI16 expression inhibits activation of caspase-1 by the AIM2-ASC inflammasome; IFI16 and AIM2 can heterodimerize, and knockdown of IFI16 increases basal and induced activation of AIM2 and NLRP3 inflammasomes in THP-1 cells. |
HEK-293 overexpression with caspase-1 assay, siRNA knockdown in THP-1, inflammasome activation assays with poly(dA:dT) and alum |
PloS one |
Medium |
22046441
|
| 2018 |
A novel transcript isoform of IFI16 (IFI16-β), lacking the pyrin domain but containing two HIN domains, is predominantly cytoplasmic and inhibits AIM2 inflammasome activation by interacting with AIM2 to impede AIM2-ASC complex formation and by sequestering cytoplasmic dsDNA. |
IFI16-β identification/cloning, co-localization assays, co-immunoprecipitation of IFI16-β with AIM2, AIM2-ASC complex formation assays, siRNA knockdown, IL-1β secretion assays |
EMBO reports |
High |
30104205
|
| 2020 |
HPV E7 recruits the E3 ligase TRIM21 to ubiquitinate and degrade the IFI16 inflammasome, inhibiting dsDNA-induced cell pyroptosis and suppressing IL-1β and IL-18 production. |
Mass spectrometry, co-immunoprecipitation of HPV E7 with IFI16 and TRIM21, ubiquitination assays, inflammasome activation and pyroptosis assays |
International journal of biological sciences |
Medium |
33061806
|
| 2006 |
Androgen receptor (AR) upregulates IFI16 expression; the IFI16 protein binds to AR in a ligand-dependent manner through AR's DNA-binding domain (DBD). Re-expression of IFI16 in LNCaP cells downregulates AR expression and inhibits AR target gene expression. |
Co-immunoprecipitation, domain mapping (DBD sufficiency), IFI16 re-expression, AR and AR target gene expression assays |
FEBS letters |
Medium |
16494870
|
| 2013 |
Extracellular IFI16 released from apoptotic cells binds to high-affinity sites on the plasma membrane of endothelial cells (Kd ~2.7 nM, ~250,000–450,000 binding sites per cell) via its N-terminal domain, inhibiting tubulogenesis and migration. Anti-IFI16 N-terminal antibodies fully reverse these effects. |
Radioiodinated IFI16 binding assays, Scatchard analysis, competition assays, co-culture experiments, endothelial function assays (tubulogenesis, migration), ELISA for circulating IFI16 |
PloS one |
Medium |
23690979
|
| 2015 |
Extracellular IFI16 activates p38 MAPK (as an early required step), subsequently activating p44/42 MAP kinases and NF-κB, inducing inflammatory cytokines (IL-6, IL-8, CCL2, CCL5, CCL20) in endothelial cells via a MyD88-dependent TLR pathway; TLR4-neutralizing antibodies partially inhibit this response. |
Recombinant IFI16 protein treatment of endothelial cells, p38/MAPK/NF-κB pathway inhibition, MyD88 siRNA knockdown, TLR4 neutralization, cytokine assays |
Journal of interferon & cytokine research |
Medium |
25715050
|
| 2020 |
Extracellular IFI16 binds with high affinity to the lipid A moiety of LPS; IFI16/LPS complexes display faster stimulation turnover on TLR4 than LPS alone, and IFI16 DAMP activity is potentiated by LPS through TLR4-MD2/TIRAP/MyD88-dependent signaling in monocytes and renal cells. |
Pull-down, saturation binding experiments, co-immunoprecipitation, surface plasmon resonance (SPR), TLR4 activation assays, cytokine induction |
PLoS pathogens |
High |
32903274
|
| 2012 |
IFI16 protein binds strongly to negatively superhelical plasmid DNA at native superhelix density and shows strong preference for cruciform DNA structure compared to linear or relaxed DNA; binding to supercoiled DNA is reversible. |
Electrophoretic mobility shift assay (EMSA) with supercoiled vs. linear DNA, oligonucleotide cruciform binding assays |
Biochemical and biophysical research communications |
Medium |
22618232
|
| 2016 |
IFI16 shows specific preference for binding to quadruplex DNA with significantly higher affinity than dsDNA or ssDNA; IFI16 stabilizes quadruplex structures from human telomere and MYC promoter sequences. H/D exchange MS shows that quadruplex DNA alters IFI16 deuteration in the PYRIN domain (aa 0–80) and structurally identical parts of both HIN domains. |
Circular dichroism spectroscopy, H/D exchange mass spectrometry, DNA binding assays with quadruplex vs. linear DNA |
PloS one |
Medium |
27280708
|
| 2025 |
IFI16 activates HMOX1 transcription by interacting with transcription factors JUND and SP1 through its pyrin domain, inhibiting ferroptosis (reducing lipid peroxidation, ROS, and Fe2+) and enhancing radioresistance in glioblastoma. Glyburide disrupts IFI16 function by targeting its pyrin domain. |
Co-immunoprecipitation of IFI16 with JUND and SP1, luciferase reporter assays for HMOX1, ferroptosis assays (lipid peroxidation, ROS, Fe2+ measurements), IFI16 knockdown/overexpression, in vivo xenograft model |
Nature communications |
Medium |
39890789
|
| 2019 |
IFI16 directly senses influenza A viral RNA via its HINa domain; IFI16 knockout cells and p204-deficient mice show reduced IFN-I production and increased IAV replication; IFI16 promotes K63-linked polyubiquitination of RIG-I by binding to RIG-I with its PYRIN domain. |
IFI16 KO cells, p204-deficient mice, RNA binding assays with HINa domain, RIG-I ubiquitination assays, co-immunoprecipitation |
Nature microbiology |
High |
33986530
|