ANKRD17

ANKRD17 is a ubiquitously expressed, nucleocytoplasmically shuttling ankyrin-repeat protein that couples cell-cycle progression to DNA replication and serves as a positive regulator of innate immune signaling (PMID:19150984, PMID:22328336). As a substrate of cyclin E/Cdk2, ANKRD17 docks via an RXL motif and is phosphorylated at Ser1791, Ser1794, and Ser2150; it associates with the MCM helicase components, Cdc6, and PCNA, and is required for loading of Cdc6 and PCNA onto chromatin, promoting replication initiation and S-phase entry (PMID:19150984). Its depletion arrests the cell cycle with upregulation of p53 and p21 (PMID:19150984). Through its ankyrin repeat domain ANKRD17 binds the RNA-sensing receptors RIG-I and MDA5 and enhances their engagement of the adaptor VISA/MAVS to drive IRF-3, NF-κB, and IFN-β activation, while its N-terminal domain binds Nod2 to support Nod1/Nod2-dependent pro-inflammatory responses to bacterial challenge such as Shigella flexneri (PMID:22328336, PMID:23711367); this immune-scaffolding function is antagonized by the influenza A virus PA-X protein, which binds the N-terminal ankyrin repeats (PMID:33241870). ANKRD17 additionally acts as a transcriptional cofactor required for YAP-driven target-gene expression, proliferation, and migration (PMID:27877230), and promotes EMT, motility, and invasion in hepatocellular carcinoma by upregulating DDR1 (PMID:40458187). Genetically, ANKRD17 is essential for embryonic vascular maturation, with knockout mice dying at midgestation from hemorrhage and loss of vascular smooth muscle cells (PMID:19619540), and haploinsufficiency produces neurodevelopmental phenotypes accompanied by synaptic and mitochondrial dysfunction (PMID:40604385).

1. 2009 High

   Established ANKRD17 as a direct cyclin E/Cdk2 effector that physically links the replication licensing and initiation machinery, answering how this previously uncharacterized protein participates in cell-cycle control.

   Evidence TAP purification, in vitro kinase assay with phosphosite mutagenesis, reciprocal Co-IP, and siRNA knockdown with chromatin-loading readout in mammalian cells

   PMID:19150984

   Open questions at the time

   • Functional consequence of the three Cdk2 phosphosites on replication factor binding not dissected
   • Whether ANKRD17 acts catalytically or as a scaffold at origins unresolved
   • Structural basis of MCM/Cdc6/PCNA engagement unknown
2. 2009 Medium

   Defined the subcellular trafficking and cell-cycle phenotype of ANKRD17, showing it is nuclear with NES/NLS signals and that its loss arrests proliferation via a p53/p21 checkpoint.

   Evidence Immunofluorescence localization, overexpression/knockdown with flow cytometry in mammalian cells

   PMID:19150984

   Open questions at the time

   • Trigger for nuclear export/import not identified
   • Whether p53/p21 induction is a direct effect or secondary to replication stress unclear
3. 2009 High

   Demonstrated an essential in vivo role in vascular maturation, showing ANKRD17 function extends beyond cultured-cell proliferation to organismal development.

   Evidence Constitutive knockout mouse with histology and vSMC marker analysis

   PMID:19619540

   Open questions at the time

   • Cell-autonomous versus non-autonomous requirement in vSMCs not separated
   • Mechanism linking replication role to vascular phenotype unaddressed
   • Paradoxical marker upregulation unexplained
4. 2012 Medium

   Identified ANKRD17 as a positive regulator of RLR antiviral signaling, recasting it as an innate immune scaffold acting through its ankyrin repeat domain.

   Evidence Reciprocal Co-IP, domain mapping, knockdown/overexpression with IRF-3 and NF-κB reporters in mammalian cells

   PMID:22328336

   Open questions at the time

   • Whether ANKRD17 stably assembles into RIG-I/MDA5/VISA complexes versus transiently bridges them unresolved
   • Relationship to its nuclear replication role not reconciled
5. 2013 Medium

   Extended the immune function to cytosolic bacterial sensing, showing ANKRD17 binds Nod2 via its N-terminus and is required for Nod1/Nod2 responses but dispensable for type I IFN to Sendai virus.

   Evidence Co-IP, domain mapping, knockdown/overexpression with Shigella flexneri infection and NF-κB reporter in myeloid and epithelial cells

   PMID:23711367

   Open questions at the time

   • Apparent discrepancy with RLR/IFN role across pathways not mechanistically explained
   • Direct versus indirect requirement in NOD signaling not distinguished
6. 2016 Medium

   Placed ANKRD17 in the Hippo pathway as a transcriptional cofactor required for YAP-driven oncogenic outputs.

   Evidence siRNA knockdown/overexpression with YAP target-gene expression and growth/migration assays in bladder cancer cells

   PMID:27877230

   Open questions at the time

   • Direct physical interaction with YAP not demonstrated
   • How a replication/immune protein cofactors transcription unresolved
7. 2021 Medium

   Revealed viral antagonism of ANKRD17 immune function, identifying its N-terminal ankyrin repeats as the binding interface for influenza A PA-X.

   Evidence Interaction screening, Co-IP, domain mapping, ANKRD17 knockout/overexpression with IAV infection

   PMID:33241870

   Open questions at the time

   • Downstream signaling steps blocked by PA-X binding not mapped
   • Whether PA-X displaces RIG-I or NOD partners from the same domain untested
8. 2025 Medium

   Implicated ANKRD17 in HCC metastasis through a DDR1-dependent, AKT-independent pro-invasive axis.

   Evidence Mouse liver tumor model with overexpression/knockdown and DDR1 suppression epistasis in invasion assays

   PMID:40458187

   Open questions at the time

   • Mechanism by which ANKRD17 upregulates DDR1 unknown
   • Relationship to YAP cofactor activity not tested
9. 2025 Medium

   Connected ANKRD17 dosage to neurodevelopment, showing haploinsufficiency disrupts behavior alongside synaptic and mitochondrial defects.

   Evidence Haploinsufficiency mouse model with behavioral assays, synaptic protein and mitochondrial function analyses, and circuit analysis after knockdown

   PMID:40604385

   Open questions at the time

   • Causal link between molecular defects and behavior not established
   • Which ANKRD17 molecular activity underlies the neuronal phenotype unknown
10. 2024 Low

    Pinpointed a disease-associated ANKRD17 short linear motif required for proliferation and identified its binding partner, offering a route to pathogenic mechanism.

    Evidence Proteome-wide base-editing SLiM dependency screen in HAP1 and RPE1 cells (preprint)

    Open questions at the time

    • Preprint with limited gene-specific mechanistic detail
    • Identity and pathway of the SLiM partner not detailed in available evidence
    • Link between the SLiM and the established replication/immune functions unclear

• How ANKRD17's distinct nuclear replication, cytoplasmic immune-scaffolding, and transcriptional-cofactor activities are integrated within one protein — and which underlies its developmental and neurodevelopmental requirements — remains unresolved.
• No structural model defining how ankyrin repeats and the central SLiM-bearing region partition functions
• No unifying mechanism connecting replication, immune, Hippo, and EMT roles
• Tissue-specific partner usage not mapped