| 2006 |
HERC5 (also known as Ceb1) is an IFN-induced HECT-type E3 protein ligase that mediates ISGylation. Its active-site cysteine (Cys-994) in the HECT domain is required for E3 ligase activity, as a C994A substitution completely abrogates ISGylation. HERC5 coexpression with Ube1L (E1) and UbcH8 (E2) reconstitutes ISG15 conjugation in vivo independent of IFN stimulation. |
Active-site mutagenesis (C994A), siRNA knockdown, co-transfection reconstitution, in vivo ISGylation assay |
Proceedings of the National Academy of Sciences of the United States of America |
High |
16815975
|
| 2005 |
Herc5 is required for ISG15 conjugation to a broad spectrum of target proteins in human cells. siRNA knockdown of Herc5 abolishes the vast majority of ISG15 conjugation. Co-transfection of ISG15, Ube1L, UbcH8, and Herc5 reconstitutes robust ISG15 conjugation in non-IFN-treated cells. The active-site cysteine mutant of Herc5 and a mutant lacking the RCC1 repeat region do not support ISG15 conjugation. |
siRNA knockdown, co-transfection reconstitution, active-site mutagenesis, domain deletion mutagenesis |
The Journal of biological chemistry |
High |
16407192
|
| 2004 |
HERC5 possesses ubiquitin ligase activity in vitro and requires the ubiquitin-conjugating enzyme UbcH5a for its activity. HERC5 protein is subject to enhanced degradation upon LPS stimulation of endothelial cells despite upregulation of its mRNA. |
In vitro ubiquitin ligase assay, subcellular fractionation/western blot, differential mRNA/protein quantification |
Journal of cell science |
Medium |
15331633
|
| 2006 |
Herc5 functions as a general E3 ISG15 ligase that physically binds target proteins and stimulates their ISGylation in a UBE1L- and UbcH8-dependent manner. Six novel ISGylation substrates were identified by proteomics and confirmed by immunoblot. |
Proteomic identification of substrates, co-immunoprecipitation, immunoblot, E1/E2 dependency assay |
Biochemical and biophysical research communications |
Medium |
16884686
|
| 2010 |
HERC5 binds IRF3 (identified by immunoprecipitation) and catalyzes ISGylation of IRF3 at Lys193, Lys360, and Lys366. This ISGylation attenuates the interaction between Pin1 and IRF3, preventing IRF3 polyubiquitination and degradation, thereby sustaining IRF3 activation and antiviral gene expression. |
Co-immunoprecipitation, site-directed mutagenesis of IRF3 lysines, siRNA knockdown, overexpression, Sendai virus infection assay |
Molecular and cellular biology |
High |
20308324
|
| 2010 |
Herc5 catalyzes ISGylation of influenza A virus NS1 protein at Lys20, Lys41, Lys108, Lys110, Lys126, Lys217, and Lys219. ISGylated NS1 fails to form homodimers and its antiviral inhibitory functions are blocked. Knockdown of Herc5 partially alleviates IFN-β-induced antiviral activity, while ectopic expression of the Herc5-mediated ISGylation system potentiates antiviral effects. |
Mass spectrometry mapping of ISGylation sites, mutagenesis, homodimerization assay, siRNA knockdown, viral replication assay, mouse infection model |
Journal of immunology |
High |
20385878
|
| 2011 |
HERC5 inhibits HIV-1 Gag particle production. E3 ligase activity of HERC5 is required for this restriction, which correlates with ISGylation of HIV-1 Gag. HERC5 interacts with HIV-1 Gag but does not alter Gag trafficking to the plasma membrane. Electron microscopy shows HIV-1 Gag particle assembly is arrested at the plasma membrane at an early stage. HERC5 also restricts murine leukemia virus Gag particle production. |
Overexpression, siRNA knockdown, co-immunoprecipitation, electron microscopy, Gag particle production assay, active-site mutant analysis |
Retrovirology |
High |
22093708
|
| 2014 |
HERC5 inhibits HIV-1 particle production by a second mechanism distinct from ISGylation: it targets nuclear export of Rev/RRE-dependent RNA via its RCC1-like domain (N-terminal), without requiring E3 ligase activity. This inhibition correlates with reduced intracellular RanGTP levels and/or impaired RanGTP–RanBP1 interaction, and with altered subcellular localization of HIV-1 Rev. A region in the RCC1-like domain under strong positive evolutionary selection is required for this activity. |
Domain deletion/mutagenesis, Rev/RRE-dependent nuclear export assay, RanGTP level measurement, RanBP1 interaction assay, subcellular localization imaging, positive selection analysis |
Retrovirology |
High |
24693865
|
| 2017 |
HERC5 physically interacts with β-catenin (immunoprecipitation) and mediates ISGylation of β-catenin, promoting its proteasomal degradation. CYP1B1 suppresses Herc5 expression, thereby stabilizing β-catenin and activating Wnt/β-catenin signaling in HeLa cells. |
Co-immunoprecipitation, RT-PCR, western blot, siRNA knockdown, CYP1B1 overexpression/inhibition |
Toxicological research |
Medium |
28744352
|
| 2021 |
HERC5 E3 ligase mediates ISGylation of hepatitis B virus X protein (HBx) at Lys91, Lys95, and Lys140. This ISGylation promotes pro-viral HBV replication and contributes to IFN-α resistance, as silencing ISG15 markedly reduced HBV replication in IFN-α-treated cells while silencing USP18 (de-ISGylase) increased replication. |
Immunoblot, site-directed mutagenesis, expression plasmids for E3 ligases, siRNA knockdown, HBV replication assay |
The Journal of general virology |
Medium |
34661519
|
| 2021 |
HERC5 recruits an adaptor protein (CREB-binding protein) to ubiquitinate CtBP1 in non-cancerous colon cells. Downregulation of HERC5 in colorectal cancer attenuates CtBP1 ubiquitination, allowing CtBP1 to accumulate and assemble a transcriptional complex with HDAC1 and c-MYC that represses pro-apoptotic genes (BAX, BIK, PUMA). |
Co-immunoprecipitation, ubiquitination assay, western blot, siRNA knockdown, overexpression, promoter binding assay, in vivo xenograft |
Carcinogenesis |
Medium |
34147029
|
| 2023 |
HERC5 (human) and mHERC6 (mouse) mediate ISGylation of the phosphatase PTEN in macrophages, promoting PTEN degradation and thereby increasing PI3K-AKT signaling and proinflammatory cytokine synthesis, enhancing antimycobacterial responses. |
Co-immunoprecipitation, ISGylation assay, siRNA knockdown, KO macrophages, PI3K-AKT pathway analysis, bacterial growth assay in vitro and in vivo |
Science signaling |
Medium |
37279284
|
| 2023 |
African swine fever virus MGF-360-10L recruits HERC5 to mediate K48-linked ubiquitination (not ISGylation) of JAK1 at Lys245 and Lys269, leading to JAK1 proteasomal degradation and suppression of STAT1/2 signaling. |
Co-immunoprecipitation, ubiquitination assay, site-directed mutagenesis, viral deletion mutant, in vivo virulence assay |
mBio |
Medium |
37417777
|
| 2024 |
HERC5 ISGylates cGAS at Lys21, Lys187, Lys219, and Lys458, promoting cGAS oligomerization and enhancing cGAS enzymatic activity. The interaction depends on the cGAS C-terminal domain and RCC1-4/RCC1-5 domains of HERC5. ISGylation deficiency attenuates cGAS-STING-mediated inflammatory gene expression and antiviral defense in mouse and human cells. |
Co-immunoprecipitation, mass spectrometry site identification, mutagenesis, cGAS activity assay, oligomerization assay, ISGylation assay, KO mouse model (HSV-1 infection) |
Cell reports |
High |
38421872
|
| 2024 |
HERC5 ISGylates SARS-CoV-2 nucleocapsid (N) protein at Lys266, Lys355, Lys387, and Lys388 (preferentially the phosphorylated form), impeding N protein oligomerization and inhibiting viral RNA synthesis. This ISGylation is reversed by PLpro (NSP3) deISGylation activity. Mutant N-4KR abolishes ISGylation and alleviates restriction in a replicon system. |
Mass spectrometry, site-directed mutagenesis, SARS-CoV-2 replicon system, oligomerization assay, ISGylation assay, PLpro activity assay |
Journal of virology |
High |
39149229 39194248
|
| 2024 |
hHERC5 broadly ISGylates proteins cotranslationally as a ribosome-associated HECT E3 ligase. Over 2,000 modified lysines in over 1,100 proteins were characterized in IFN-β-stimulated cells. hHERC5 and mouse HERC6 have distinct amino acid sequence context preferences surrounding ISGylation sites. mHERC6 also cotranslationally modifies nascent polypeptides. |
Mass spectrometry ISGylome profiling, IFN-β stimulation, sequence context analysis, comparison with mHERC6 |
iScience |
High |
38303729
|
| 2022 |
HERC5 interacts with IFI16 and mediates ISGylation of IFI16 at Lys274, facilitating IFI16 proteasomal degradation. IFI16 acts as a tumor suppressor downstream of HERC5, and IFI16 is positively correlated with p53 expression, defining a HERC5/IFI16/p53 signaling pathway in breast cancer cells. |
Co-immunoprecipitation, proteomic analysis, western blot, siRNA knockdown, site mutagenesis, cell proliferation/migration assays |
Life sciences |
Medium |
35671810
|
| 2021 |
HERC5 inhibits Ebola virus (EBOV) VLP replication by depleting EBOV mRNAs. The RCC1-like domain of HERC5 is necessary and sufficient for this inhibition and does not require zinc finger antiviral protein (ZAP). EBOV glycoprotein (Zaire strain) antagonizes HERC5 early during infection. |
Transcription- and replication-competent VLP system, domain deletion analysis, ZAP-deficient cell assay, EBOV GP antagonism assay |
Cells |
Medium |
34572049
|
| 2025 |
HERC5 ISGylates SARS-CoV-2 nsp8 (a viral replication factor) at its N2 domain lysine residues, facilitating proteasome-dependent nsp8 degradation and suppressing viral replication. SARS-CoV-2 PLpro counteracts this by deconjugating ISG15 from nsp8, preventing its degradation. The full ISGylation system (HERC5, UBA7, ISG15) suppresses replication of multiple SARS-CoV-2 variants including Omicron. |
Mass spectrometry, mutagenesis, overexpression, PLpro deISGylation assay, proteasome inhibition, viral replication assay |
International journal of biological macromolecules |
Medium |
40409630
|
| 2025 |
HERC5 catalyzes ISGylation of UGDH (UDP-glucose 6-dehydrogenase) via its HECT domain active-site Cys994, facilitating UGDH phosphorylation and enhancing SNAI1 mRNA stability, thereby promoting OSCC cell invasion and cisplatin resistance. |
Co-immunoprecipitation, ISGylation assay, site mutagenesis (C994A), siRNA knockdown, overexpression, in vivo xenograft |
Biology direct |
Medium |
40045362
|
| 2025 |
HERC5 inhibits LINE-1 (L1) retrotransposition through an ISGylation-independent mechanism. HERC5 interacts with L1 RNA and selectively reduces ORF1p protein levels, decreasing L1 translation efficiency and altering L1 RNP composition. |
L1 retrotransposition assay, HERC5 domain/catalytic mutant analysis, RNA immunoprecipitation, ORF1p level quantification, RNP composition analysis |
Nucleic acids research |
Medium |
42055552
|
| 2025 |
UbcH8~ISG15 exhibits striking specificity for HECT-family E3 ligases (particularly HERC5) but is inactive with RING or RBR E3s, in contrast to UbcH8~Ub which preferentially engages RBR E3s. A unique closed conformation of UbcH8~ISG15 enables trans-thiolation selectively mediated by HECT E3s. HERC5's C-lobe specifically recognizes donor ISG15 for lysine conjugation, explaining its exclusive ISGylation activity and lack of ubiquitination function. |
Structural analysis (biochemical studies), in vitro thiolation assay, comparative E3 ligase specificity assay |
bioRxivpreprint |
Medium |
bio_10.1101_2025.09.26.678755
|
| 2025 |
SAXS analysis reveals that the HERC5 HECT domain predominantly adopts a trimeric assembly in solution, suggesting trimerization may play a regulatory role in HERC5 functional activity. |
Small-angle X-ray scattering (SAXS), size-exclusion chromatography, Guinier/Kratky analysis, ab initio shape reconstruction |
bioRxivpreprint |
Low |
bio_10.1101_2025.03.22.644726
|
| 2024 |
HERC5 (human) and HERC6 (mouse functional homolog) are the primary E3 ligases responsible for ISGylation of MDA5 at Lys23 and Lys43 within its CARD domain. ISGylation at these sites promotes MDA5 oligomeric assembly and downstream antiviral signaling; knock-in mice with K23R/K43R MDA5 mutations show abrogated ISGylation, impaired MDA5 oligomerization, blunted cytokine responses, and increased mortality upon EMCV infection. |
MDA5 K23R/K43R knock-in mice, ISGylation assay, MDA5 oligomerization assay, cytokine measurement, viral infection survival assay, E3 ligase identification |
bioRxivpreprint |
Medium |
bio_10.1101_2024.09.20.614144
|
| 2025 |
HERC5 interacts with and ISGylates IRF3, preventing IRF3 ubiquitination and degradation. This stabilizes IRF3 and sustains IFN-β production and overactivation in podocytes, contributing to lupus nephritis pathology. |
Co-immunoprecipitation, siRNA knockdown, overexpression, ISGylation assay, IFN-β quantification, podocyte injury assay |
International immunopharmacology |
Medium |
40505230
|