Affinage

ZYG11B

Protein zyg-11 homolog B · UniProt Q9C0D3

Length
744 aa
Mass
83.9 kDa
Annotated
2026-06-11
11 papers in source corpus 10 papers cited in narrative 10 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 6/6 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

ZYG11B is the substrate-recognition subunit of the CRL2ZYG11B E3 ubiquitin ligase, which targets proteins bearing small N-terminal residues for proteasomal degradation through the N-degron pathway [PMID:34214466, PMID:bio_10.1101_2024.06.24.600508]. Its armadillo repeats form a deep, narrow cavity whose acidic pocket coordinates the α-amino group of an N-terminal glycine through five conserved hydrogen bonds, accounting for selective Gly/N-degron recognition; the same site also engages unacetylated Ser, Ala, and Cys, residues that N-terminal acetyltransferases normally shield from ZYG11B in cells (PMID:34214466, PMID:36496439). Full-length ZYG11B folds into a leucine-rich repeat domain followed by two armadillo domains and assembles into the holoenzyme via EloB/EloC adaptors and CUL2, with adaptor-binding, substrate-binding, and dimerization interfaces all required for substrate degradation; ZYG11B can dimerize to present two substrate sites [PMID:41917018, PMID:bio_10.1101_2024.06.24.600508]. Through this activity it ubiquitinates physiological and pathogen-derived substrates: it promotes NLRP1 inflammasome activation by recognizing the Gly/N-degron exposed after viral protease cleavage of NLRP1 [PMID:bio_10.1101_2024.06.24.600508], and it restricts enteroviruses by K33-linked ubiquitination of the structural protein VP1 (PMID:40135890). Independently of its ligase role, ZYG11B amplifies cGAS-mediated innate immune signaling by enhancing cGAS–DNA binding and condensation to potentiate cGAMP production (PMID:36933219). ZYG11B has also been repurposed as an E3 warhead for aptamer-bridged targeted protein degradation of neo-substrates (PMID:40082426).

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 2020 Medium

    Before its biochemical role was defined, ZYG11B was linked to vertebrate development, establishing a phenotypic consequence of disrupting the gene.

    Evidence Mutant-vs-wild-type localization in HeLa cells plus morpholino knockdown in zebrafish with SOX6 expression readout

    PMID:32738032

    Open questions at the time
    • Does not connect the developmental phenotype to E3 ligase activity or specific substrates
    • Morpholino knockdown lacks genetic rescue
    • Truncating-mutation localization effect not mechanistically explained
  2. 2021 High

    Crystal structures defined how ZYG11B reads an N-terminal glycine, establishing the structural basis of Gly/N-degron recognition by CRL2ZYG11B.

    Evidence X-ray crystallography of ZYG11B–Gly/N-degron peptide complexes with biochemical binding assays

    PMID:34214466

    Open questions at the time
    • Used isolated armadillo-domain structures rather than the full holoenzyme
    • Did not address physiological substrate identity
    • Catalytic ubiquitin transfer not visualized
  3. 2021 Medium

    A test of whether SARS-CoV-2 ORF10 hijacks CRL2ZYG11B showed physical interaction via the ORF10 N-terminus but no functional requirement, ruling out a ubiquitin-ligase-hijacking model.

    Evidence Reciprocal Co-IP, N-terminal deletion analysis, and ZYG11B/ZER1 knockout infection assays

    PMID:33827988

    Open questions at the time
    • Does not explain why ORF10 binds ZYG11B if not to modulate it
    • Negative infection result confined to cultured cells
  4. 2022 High

    Extending the degron repertoire, ZYG11B was shown to recognize unacetylated Ser/Ala/Cys N-termini, integrating N-terminal acetylation status into substrate selection.

    Evidence In vitro binding, degradation assays in NAT-deficient cells, and X-ray crystallography of small-Nt-residue complexes

    PMID:36496439

    Open questions at the time
    • Endogenous substrates exposed in NAT-deficient states not enumerated
    • Relative in vivo contribution versus paralog ZER1 not resolved
  5. 2022 Medium

    A co-crystal structure detailed how ZYG11B's substrate cavity engages the ORF10 N-terminal peptide, structurally rationalizing the earlier interaction.

    Evidence X-ray crystallography of the ZYG11B–ORF10 N-terminal peptide complex

    PMID:35636250

    Open questions at the time
    • No accompanying mutagenesis or functional validation
    • Does not reconcile binding with the lack of functional consequence for infection
  6. 2023 Medium

    ZYG11B was found to act outside its E3 role as a positive regulator of cGAS, revealing a moonlighting function in innate immune signaling.

    Evidence ZYG11B knockdown with cGAMP measurement, cGAS-DNA-ZYG11B pulldown, condensation assays, and HSV-1 infection assays

    PMID:36933219

    Open questions at the time
    • Mechanism linking ZYG11B binding to condensate stabilization not structurally defined
    • Whether ligase activity contributes to cGAS regulation unresolved
    • HSV-1-induced ZYG11B degradation pathway unidentified
  7. 2024 Medium

    Holoenzyme cryo-EM with an NLRP1 degron tied ZYG11B's degron recognition to inflammasome biology, showing it ubiquitinates the Gly/N-degron exposed by viral protease cleavage of NLRP1.

    Evidence Cryo-EM of CRL2-ZYG11B ± NLRP1 Gly/N-degron peptide, in vitro ubiquitination, and inflammasome activation/blocking assays (preprint)

    PMID:bio_10.1101_2024.06.24.600508

    Open questions at the time
    • Preprint without peer review
    • Physiological breadth of NLRP1 regulation in primary immune cells not established
  8. 2025 Medium

    ZYG11B was shown to restrict enteroviruses by K33-linked ubiquitination of VP1, demonstrating antiviral substrate targeting and mapping the required ZYG11B domains.

    Evidence Mass spectrometry, Co-IP, domain mapping, proteasome inhibitor and K33-linkage analysis, and viral replication assays

    PMID:40135890

    Open questions at the time
    • In vivo antiviral relevance not tested
    • Why K33 rather than K48 linkage is used mechanistically unclear
  9. 2025 Medium

    A non-inhibitory aptamer warhead established ZYG11B as a recruitable E3 for targeted protein degradation, enabling neo-substrate destruction in vivo.

    Evidence Aptamer selection, ZATAC degradation assays for nucleolin/SOX2/p53-R175H, and tumor xenograft experiments

    PMID:40082426

    Open questions at the time
    • Endogenous-substrate physiology not addressed by this engineering study
    • Long-term specificity and toxicity beyond xenografts unknown
  10. 2026 High

    Full-length cryo-EM resolved how ZYG11B assembles with EloB/EloC and dimerizes, establishing the complete architecture required for substrate degradation.

    Evidence Cryo-EM of full-length ZYG11B–EloB–EloC–substrate complex with interface mutagenesis and degradation assays

    PMID:41917018

    Open questions at the time
    • Functional advantage of dimer over monomer in cells not quantified
    • Dynamics of substrate hand-off to the catalytic module not captured

Open questions

Synthesis pass · forward-looking unresolved questions
  • How ZYG11B's ligase-dependent N-degron functions and its ligase-independent cGAS regulation are coordinated, and the full endogenous substrate set, remain open.
  • No comprehensive endogenous substrate catalog
  • Relationship between developmental phenotypes and defined substrates unestablished
  • Division of labor with paralog ZER1 unresolved

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0016874 ligase activity 2 GO:0060089 molecular transducer activity 2 GO:0140096 catalytic activity, acting on a protein 2 GO:0098772 molecular function regulator activity 1
Pathway
R-HSA-168256 Immune System 3 R-HSA-392499 Metabolism of proteins 3
Complex memberships
CRL2ZYG11B

Evidence

Reading pass · 10 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2021 Crystal structures of ZYG11B bound to various Gly/N-degrons reveal that ZYG11B uses its armadillo (ARM) repeats to form a deep and narrow cavity that engages mainly the first four residues of Gly/N-degrons, with the α-amino group of the degron accommodated in an acidic pocket via five conserved hydrogen bonds, establishing the structural basis for specific Gly/N-degron recognition by the CRL2ZYG11B E3 ubiquitin ligase complex. X-ray crystallography of ZYG11B bound to Gly/N-degron peptides, combined with biochemical binding assays Molecular cell High 34214466
2021 SARS-CoV-2 ORF10 physically interacts with ZYG11B (the substrate receptor of CRL2ZYG11B), and the N-terminus of ORF10 is critical for this interaction; however, ORF10 does not function to inhibit or hijack CRL2ZYG11B, and ZYG11B (and its paralog ZER1) are dispensable for SARS-CoV-2 infection in cultured cells. Co-immunoprecipitation, N-terminal deletion analysis, ZYG11B/ZER1 knockout cell infection assays Proceedings of the National Academy of Sciences of the United States of America Medium 33827988
2020 A truncating mutation in ZYG11B (p.Glu537*) produces a protein with altered subcellular localization in HeLa cells compared to wild-type ZYG11B; knockdown of the zebrafish ZYG11B homologue disrupts craniofacial cartilage architecture and notochord development, and ZYG11B expression regulates the cartilage master regulator SOX6 and is regulated by retinoic acid. Overexpression and immunofluorescence of wild-type vs. mutant ZYG11B in HeLa cells; morpholino-based knockdown in zebrafish embryos with phenotypic readout; RT-qPCR for SOX6 Molecular genetics & genomic medicine Medium 32738032
2022 ZYG11B (as part of CRL2ZYG11B) recognizes not only N-terminal glycine but also small Nt-residues (Ser, Ala, Cys) in vitro; however, Nt-acetylation of Ser, Ala, and Cys by N-terminal acetyltransferases (NATs) shields these residues from ZYG11B recognition in cells, while in NAT-deficient cells ZYG11B/ZER1 targets these unacetylated small Nt-residues for proteasomal degradation. Crystal structures of ZYG11B bound to these small Nt-residues reveal the molecular mechanism of non-acetylated substrate recognition. In vitro binding assays, cellular degradation assays in NAT-deficient cells, X-ray crystallography Nature communications High 36496439
2023 ZYG11B acts as an amplifier of cGAS-mediated innate immune signaling by enhancing cGAS-DNA binding affinity, potentiating cGAS-DNA condensation, and stabilizing the cGAS-DNA condensed complex, thereby promoting cGAMP production and downstream interferon/cytokine transcription; knockdown of ZYG11B impairs these responses. Additionally, HSV-1 infection induces ZYG11B degradation in a cGAS-independent manner. ZYG11B knockdown with cGAMP measurement, co-immunoprecipitation/pulldown for cGAS-DNA-ZYG11B interaction, condensation assays, HSV-1 infection assays Cell reports Medium 36933219
2022 Crystal structure of ZYG11B bound to the N-terminal peptide of SARS-CoV-2 ORF10 reveals the structural basis for recognition of the ORF10 N-terminus by ZYG11B's substrate-binding cavity. X-ray crystallography of ZYG11B–ORF10 N-terminal peptide complex Biochemical and biophysical research communications Medium 35636250
2025 ZYG11B, as part of the CRL2ZYG11B complex, targets Enterovirus 71 (EV71) structural protein VP1 for proteasomal degradation via K33-linked ubiquitination; mass spectrometry and immunoprecipitation confirmed the ZYG11B–VP1 interaction and identified key domains on ZYG11B required for VP1 binding and CUL2 recruitment. ZYG11B also restricts related enteroviruses (CA6, CA16, EVD68) whose VP1 ubiquitination sites are highly conserved. Mass spectrometry, co-immunoprecipitation, domain mapping, proteasome inhibitor assays, K33 ubiquitination linkage analysis, viral replication functional assays Journal of virology Medium 40135890
2026 Cryo-EM structures of full-length human ZYG11B in complex with EloB-EloC adaptor and a Gly/N-degron peptide reveal a seahorse-like architecture with distinct interfaces for adaptor binding and substrate engagement. ZYG11B adopts both monomeric and dimeric assemblies, with the dimer stabilizing two substrate-binding sites in opposite orientations. Functional assays demonstrate that interfaces mediating adaptor recruitment, substrate binding, and dimerization are all essential for substrate degradation. Cryo-EM structure determination of full-length ZYG11B–EloB–EloC–substrate complex; mutagenesis of assembly interfaces with substrate degradation functional assays Nature communications High 41917018
2024 Cryo-EM structures of the full CRL2-ZYG11B holoenzyme alone and in complex with a Gly/N-degron peptide from NLRP1 reveal that ZYG11B folds into a Leucine-Rich Repeat domain followed by two armadillo repeat domains that mediate CRL2 assembly and NLRP1 Gly/N-degron recognition. ZYG11B promotes NLRP1 inflammasome activation by recognizing and ubiquitinating the Gly/N-degron exposed after viral protease cleavage of NLRP1; blocking ZYG11B recognition of this degron inhibits viral protease-mediated NLRP1 inflammasome activation. Cryo-EM structure of CRL2-ZYG11B holoenzyme ± Gly/N-degron peptide; in vitro ubiquitination assays; functional inflammasome activation assays with blocking experiments bioRxivpreprint Medium bio_10.1101_2024.06.24.600508
2025 A non-inhibitory DNA aptamer targeting ZYG11B was identified and validated as an E3 ligase warhead for PROTAC-based targeted protein degradation (ZATAC platform), demonstrating that ZYG11B can be recruited to degrade diverse neo-substrates (nucleolin, SOX2, mutant p53-R175H) when bridged via an aptamer, and that cancer-cell-targeted 3WJ-ZATACs achieve dual-target degradation and suppress tumor growth in vivo without noticeable toxicity. Aptamer selection and binding validation; PROTAC/ZATAC functional degradation assays for multiple target proteins; in vivo tumor xenograft experiments Nature communications Medium 40082426

Source papers

Stage 0 corpus · 11 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2021 Molecular basis for recognition of Gly/N-degrons by CRL2ZYG11B and CRL2ZER1. Molecular cell 36 34214466
2021 ORF10-Cullin-2-ZYG11B complex is not required for SARS-CoV-2 infection. Proceedings of the National Academy of Sciences of the United States of America 31 33827988
2020 Functional and genetic analyses of ZYG11B provide evidences for its involvement in OAVS. Molecular genetics & genomic medicine 28 32738032
2022 CRL2ZER1/ZYG11B recognizes small N-terminal residues for degradation. Nature communications 25 36496439
2023 ZYG11B potentiates the antiviral innate immune response by enhancing cGAS-DNA binding and condensation. Cell reports 19 36933219
2023 LncRNA LINC01871 sponging miR-142-3p to modulate ZYG11B promotes the chemoresistance of colorectal cancer cells by inducing autophagy. Anti-cancer drugs 14 36847071
2025 Identification of a non-inhibitory aptameric ligand to CRL2ZYG11B E3 ligase for targeted protein degradation. Nature communications 11 40082426
2022 Silencing of circular RNA‑ZYG11B exerts a neuroprotective effect against retinal neurodegeneration. International journal of molecular medicine 7 35730627
2022 Structural insights into ORF10 recognition by ZYG11B. Biochemical and biophysical research communications 5 35636250
2025 ZYG11B suppresses multiple enteroviruses by triggering viral VP1 degradation. Journal of virology 3 40135890
2026 Structures of ZYG11B-EloB-EloC-substrate complex reveal mechanisms of CRL2ZYG11B assembly and function. Nature communications 0 41917018

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