ANK2

Ankyrin-B (ANK2) is a cytoskeletal scaffold protein that organizes membrane protein complexes in cardiomyocytes and neurons by targeting ion channels and transporters—including Na/Ca exchanger, Na/K ATPase, NaV1.2, Kv7.2/Kv7.3, and KCNH2—to specific subcellular domains, thereby governing cardiac electrogenesis and neuronal excitability (PMID:17242276, PMID:38290518, PMID:37321992, PMID:30929919). In neurons, a giant neurospecific isoform localizes to periodic axonal plasma membrane domains via L1-CAM interactions and couples microtubules to the plasma membrane to limit axon branching; loss of ankyrin-B disrupts axon initial segment organization, impairs dendritic excitability, causes network hyperexcitability and seizures, and alters inhibitory synapse connectivity (PMID:31285321, PMID:37195288, PMID:37428632). ANK2 loss-of-function variants cause cardiac arrhythmias through mislocalization of its binding partners at the sarcoplasmic reticulum membrane, while ASD-associated mutations disrupt NrCAM and β2-Spectrin binding and impair spine pruning and cortical connectivity (PMID:27298202, PMID:17242276). Ankyrin-B protein stability is regulated by USP46-mediated deubiquitination, and its isoform expression is controlled by PTBP2-dependent alternative splicing of exon 36 (PMID:40878243, PMID:41555757).

1. 2007 High

   Establishing that ankyrin-B functions as a cardiac scaffold whose loss-of-function variants mislocalize Na/Ca exchanger, Na/K ATPase, and IP3 receptor at the sarcoplasmic reticulum, answering how ANK2 mutations cause arrhythmia at the cellular level.

   Evidence Expression of nine ANK2 variants in primary cardiomyocytes with immunofluorescence localization and functional assays

   PMID:17242276

   Open questions at the time

   • Structural basis for how specific ANK2 domains discriminate among binding partners was unknown
   • In vivo arrhythmia phenotype for individual variants not yet demonstrated in animal models
2. 2016 High

   Demonstrating that a specific ANK2 missense variant (L1622I) causes catecholamine-dependent arrhythmias in vivo by reducing association with Na/Ca exchanger and prolonging action potential duration, moving from cell-based partner mislocalization to a defined electrophysiological mechanism in an intact heart.

   Evidence Knock-in mouse model with co-immunoprecipitation, cardiomyocyte patch-clamp, and in vivo arrhythmia testing

   PMID:27298202

   Open questions at the time

   • Whether the arrhythmia mechanism generalizes to other ANK2 variants was not resolved
   • Contribution of other ion channel partners (e.g., KCNH2) to the arrhythmia phenotype was untested
3. 2017 Medium

   Identifying the membrane-binding domain as a critical determinant of ankyrin-B expression and partner targeting, showing that the S646F variant reduces protein levels and specifically impairs Na/Ca exchanger membrane localization.

   Evidence Biochemical expression assays in H9c2 cells and immunofluorescence in primary cardiomyocytes

   PMID:28196901

   Open questions at the time

   • Whether reduced expression reflects protein instability or impaired folding was not distinguished
   • Single-lab study without independent replication
4. 2019 High

   Revealing a neuron-specific function: giant ankyrin-B localizes to periodic axonal domains via L1-CAM, couples microtubules to the plasma membrane, and limits axon branching; an ASD-associated mutation disrupts this mechanism causing ectopic connectivity and behavioral deficits.

   Evidence Cultured neuron imaging, ASD knock-in mouse model, axon branching assays, and behavioral analysis

   PMID:31285321

   Open questions at the time

   • Molecular details of the ankyrin-B–microtubule coupling interface were not resolved
   • Whether ectopic branching directly causes ASD-like behaviors versus other circuit alterations was unclear
5. 2019 Medium

   Extending the cardiac channel repertoire: ANK2 functionally modulates KCNH2 (hERG) channel currents and trafficking, with ANK2 disease variant E1813K diminishing hERG-mediated currents.

   Evidence Xenopus oocyte voltage-clamp electrophysiology and HEK293 cell trafficking assay with co-expression

   PMID:30929919

   Open questions at the time

   • Direct physical interaction between full-length ankyrin-B and KCNH2 not demonstrated by reciprocal co-IP
   • In vivo relevance of ANK2-KCNH2 interaction untested
6. 2019 Medium

   ANK2 phosphorylation at Ser3781 is markedly reduced downstream of PINK1 loss in a Parkinson's disease model, placing ankyrin-B in a PINK1-dependent pathway linking cytoskeletal organization to neurodegeneration.

   Evidence Quantitative phosphoproteomics of PINK1-KO/A53T-SNCA mouse brain with immunoblot validation

   PMID:31277379

   Open questions at the time

   • Functional consequence of Ser3781 phosphorylation on ankyrin-B activity or localization not tested
   • Single phosphoproteomics dataset without independent validation of the PINK1–ANK2 axis
7. 2019 Medium

   Identifying a non-neuronal/non-cardiac role: an oocyte-specific ANK2 transcript variant (Ank2.3) is stored in the nucleoplasm and translated at the spindle after nuclear envelope breakdown; blocking its translation causes cytokinesis defects.

   Evidence RT-PCR, RNA localization imaging, translational reporter assay, and morpholino knockdown in mouse oocytes

   PMID:31511568

   Open questions at the time

   • Mechanism by which spindle-localized ankyrin-B supports cytokinesis not defined
   • Single-lab finding not independently replicated
8. 2022 Medium

   Demonstrating a developmental role for ANK2 in neural stem cell differentiation and cortical neuronal migration, expanding its function beyond mature neuron physiology.

   Evidence In utero electroporation knockdown in mouse cortex with immunofluorescence and transcriptomic analysis

   PMID:35313230

   Open questions at the time

   • Specific molecular targets mediating migration defects not identified
   • Single-lab study with knockdown only, no rescue experiment
9. 2023 High

   Establishing that ankyrin-B is required for Kv7.2/Kv7.3 targeting to the axon initial segment and AIS length regulation; its loss causes neuronal hyperexcitability and seizures that are rescued by the Kv7 agonist retigabine, directly linking ANK2 to epilepsy pathophysiology.

   Evidence Conditional Ank2 knockout in cortical/hippocampal excitatory neurons, electrophysiology, AIS immunofluorescence, pharmacological rescue

   PMID:37321992

   Open questions at the time

   • Whether AIS elongation is a direct structural consequence of ankyrin-B loss or a compensatory response was not resolved
   • Contribution of other AIS-localized channels beyond Kv7 to the seizure phenotype not dissected
10. 2023 High

    Multi-omics analysis of Ank2-deficient cortex revealed remodeling of the synaptic proteome (upregulated spine plasticity proteins, downregulated intermediate filaments), network hypersynchrony, and partial rescue by AMPA receptor blockade, establishing ankyrin-B as a regulator of excitatory synaptic organization and AIS homeostatic plasticity.

    Evidence Conditional knockout mice (Emx1-Cre), calcium imaging, quantitative synaptic proteomics, interactome characterization, and pharmacological rescue; complemented by CRISPR heterozygous LOF in hiPSC-derived neurons with MEA recordings

    PMID:37195288 PMID:37428632

    Open questions at the time

    • Causal chain from ankyrin-B loss to synaptic proteome remodeling not mechanistically delineated
    • Whether MAVS-dependent inflammation (see 2025) contributes to neuronal phenotypes was not explored
11. 2024 High

    Functional convergence of two major ASD risk genes was established: ankyrin-B scaffolds NaV1.2 to dendritic membranes, and Ank2 haploinsufficiency phenocopies Scn2a haploinsufficiency in dendritic excitability and synaptic function.

    Evidence Conditional Ank2 haploinsufficiency mice, patch-clamp electrophysiology, immunofluorescence, genetic epistasis

    PMID:38290518

    Open questions at the time

    • Whether ankyrin-B directly binds NaV1.2 or requires an intermediate adaptor not resolved
    • Behavioral consequences of the dendritic excitability deficit not reported in this study
12. 2025 Medium

    Post-translational regulation of ankyrin-B was elucidated: USP46 deubiquitinates and stabilizes ANK2 protein, and this axis modulates cardiomyocyte survival during ischemia/reperfusion by regulating apoptosis, inflammation, and ferroptosis.

    Evidence Ubiquitination assay, cycloheximide chase, siRNA knockdown and overexpression rescue in AC16 cardiomyocytes and rat I/R model

    PMID:40878243

    Open questions at the time

    • Specific ubiquitin sites on ANK2 not mapped
    • Whether USP46-ANK2 regulation operates in neurons not tested
13. 2025 Medium

    ANK2 deficiency was linked to mitochondrial dysfunction and innate immune activation: loss of ankyrin-B causes cristae disorganization, MAVS oligomerization, and IL-6/IL-8 secretion, defining an ANK2-MAVS-IL-8 inflammatory axis.

    Evidence ANK2 knockdown with multi-omics (RNA-seq, proteomics, metabolomics, ATAC-seq), MAVS oligomerization assay, cytokine measurement

    PMID:41248744

    Open questions at the time

    • Mechanism by which ankyrin-B maintains mitochondrial cristae integrity not defined
    • In vivo relevance of the ANK2-MAVS axis not demonstrated
14. 2025 Medium

    Isoform-level regulation was defined: PTBP2 controls alternative splicing of ANK2 exon 36, and this exon is required for efficient neuronal reprogramming, establishing a splicing-dependent regulatory axis for ANK2 function.

    Evidence Transcriptomic/splicing analysis, PTBP2 knockdown, functional rescue with ANK2 exon 36 re-expression in hRPE-19 cells

    PMID:41555757

    Open questions at the time

    • Function of the exon 36-encoded domain at the protein level not characterized
    • Whether PTBP2-dependent splicing regulates ANK2 in endogenous neuronal development not tested

• Key open questions include the high-resolution structural basis for ankyrin-B's selective recognition of diverse membrane partners, the in vivo relevance of the ANK2-MAVS inflammatory axis, the mechanism by which ankyrin-B maintains mitochondrial integrity, and whether the USP46-mediated stabilization pathway operates in neurons.
• No high-resolution experimental structure of full-length ankyrin-B or its multi-partner complexes
• Functional significance of PINK1-dependent ANK2 phosphorylation remains untested
• Integration of cardiac, neuronal, and inflammatory functions into a unified model is lacking