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Action potential propagation along myelinated axons requires clustered voltage-gated sodium and potassium channels. These channels must be restricted to nodes of Ranvier where the action potential is regenerated. Several mechanisms have evolved to facilitate and ensure the correct assembly and stabilization of these essential axonal domains. This review highlights the current understanding of the axon-intrinsic and glial-extrinsic mechanisms that control the formation and maintenance of the nodes of Ranvier in both the peripheral (PNS) and central (CNS) nervous systems.
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The evolution of ion channel clustering at nodes of Ranvier enabled the development of complex vertebrate nervous systems. At mammalian nodes, the K+ leak channels TRAAK and TREK-1 underlie membrane repolarization. Despite the molecular similarities between nodes and the axon initial segment (AIS), TRAAK and TREK-1 are reportedly node-specific, suggesting a unique clustering mechanism. However, we show that TRAAK and TREK-1 are enriched at both nodes and AIS through a common mechanism. We identified a motif near the C-terminus of TRAAK that is necessary and sufficient for its clustering. The motif first evolved among cartilaginous fish. Using AnkyrinG (AnkG) conditional knockout mice, CRISPR/Cas9-mediated disruption of AnkG, co-immunoprecipitation, and surface recruitment assays, we show that TRAAK forms a complex with AnkG and that AnkG is necessary for TRAAK's AIS and nodal clustering. In contrast, TREK-1's clustering requires TRAAK. Our results expand the repertoire of AIS and nodal ion channel clustering mechanisms and emphasize AnkG's central role in assembling excitable domains.
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Ancirinas , Axones , Ratones Noqueados , Canales de Potasio de Dominio Poro en Tándem , Animales , Canales de Potasio de Dominio Poro en Tándem/metabolismo , Canales de Potasio de Dominio Poro en Tándem/genética , Axones/metabolismo , Ratones , Ancirinas/metabolismo , Ancirinas/genética , Nódulos de Ranvier/metabolismo , Humanos , Secuencias de Aminoácidos , Evolución MolecularRESUMEN
In the mouse embryonic forebrain, developmentally distinct oligodendrocyte progenitor cell populations and their progeny, oligodendrocytes, emerge from three distinct regions in a spatiotemporal gradient from ventral to dorsal. However, the functional importance of this oligodendrocyte developmental heterogeneity is unknown. Using a genetic strategy to ablate dorsally derived oligodendrocyte lineage cells (OLCs), we show here that the areas in which dorsally derived OLCs normally reside in the adult central nervous system become populated and myelinated by OLCs of ventral origin. These ectopic oligodendrocytes (eOLs) have a distinctive gene expression profile as well as subtle myelination abnormalities. The failure of eOLs to fully assume the role of the original dorsally derived cells results in locomotor and cognitive deficits in the adult animal. This study reveals the importance of developmental heterogeneity within the oligodendrocyte lineage and its importance for homeostatic brain function.
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Encéfalo , Linaje de la Célula , Oligodendroglía , Animales , Oligodendroglía/fisiología , Ratones , Encéfalo/citología , Encéfalo/embriología , Linaje de la Célula/fisiología , Diferenciación Celular/fisiología , Ratones Transgénicos , Vaina de Mielina/metabolismo , Vaina de Mielina/fisiologíaRESUMEN
Vertebrate nervous systems use the axon initial segment (AIS) to initiate action potentials and maintain neuronal polarity. The microtubule-associated protein tripartite motif containing 46 (TRIM46) was reported to regulate axon specification, AIS assembly, and neuronal polarity through the bundling of microtubules in the proximal axon. However, these claims are based on TRIM46 knockdown in cultured neurons. To investigate TRIM46 function in vivo , we examined TRIM46 knockout mice. Contrary to previous reports, we find that TRIM46 is dispensable for AIS formation and maintenance, and axon specification. TRIM46 knockout mice are viable, have normal behavior, and have normal brain structure. Thus, TRIM46 is not required for AIS formation, axon specification, or nervous system function. We also show TRIM46 enrichment in the first â¼100 µm of axon occurs independently of ankyrinG (AnkG), although AnkG is required to restrict TRIM46 only to the AIS. Our results suggest an unidentified protein may compensate for loss of TRIM46 in vivo and highlight the need for further investigation of the mechanisms by which the AIS and microtubules interact to shape neuronal structure and function. SIGNIFICANCE STATEMENT: A healthy nervous system requires the polarization of neurons into structurally and functionally distinct compartments, which depends on both the axon initial segment (AIS) and the microtubule cytoskeleton. In contrast to previous reports, we show that the microtubule-associated protein TRIM46 is not required for axon specification or AIS formation in mice. Our results emphasize the need for further investigation of the mechanisms by which the AIS and microtubules interact to shape neuronal structure and function.
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The bipolar disorder (BD) risk gene ANK3 encodes the scaffolding protein AnkyrinG (AnkG). In neurons, AnkG regulates polarity and ion channel clustering at axon initial segments and nodes of Ranvier. Disruption of neuronal AnkG causes BD-like phenotypes in mice. During development, AnkG is also expressed at comparable levels in oligodendrocytes and facilitates the efficient assembly of paranodal junctions. However, the physiological roles of glial AnkG in the mature nervous system, and its contributions to BD-like phenotypes, remain unexplored. Here, we generated oligodendroglia-specific AnkG conditional knockout mice and observed the destabilization of axoglial interactions in aged but not young adult mice. In addition, these mice exhibited profound histological, electrophysiological, and behavioral pathophysiologies. Unbiased translatomic profiling revealed potential compensatory machineries. These results highlight the critical functions of glial AnkG in maintaining proper axoglial interactions throughout aging and suggests a previously unrecognized contribution of oligodendroglial AnkG to neuropsychiatric disorders.
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Spectrins function together with actin as obligatory subunits of the submembranous cytoskeleton. Spectrins maintain cell shape, resist mechanical forces, and stabilize ion channel and transporter protein complexes through binding to scaffolding proteins. Recently, pathogenic variants of SPTBN4 (ß4 spectrin) were reported to cause both neuropathy and myopathy. Although the role of ß4 spectrin in neurons is mostly understood, its function in skeletal muscle, another excitable tissue subject to large forces, is unknown. Here, using a muscle specific ß4 spectrin conditional knockout mouse, we show that ß4 spectrin does not contribute to muscle function. In addition, we show ß4 spectrin is not present in muscle, indicating the previously reported myopathy associated with pathogenic SPTBN4 variants is neurogenic in origin. More broadly, we show that α2, ß1 and ß2 spectrins are found in skeletal muscle, with α2 and ß1 spectrins being enriched at the postsynaptic neuromuscular junction (NMJ). Surprisingly, using muscle specific conditional knockout mice, we show that loss of α2 and ß2 spectrins had no effect on muscle health, function or the enrichment of ß1 spectrin at the NMJ. Muscle specific deletion of ß1 spectrin also had no effect on muscle health, but, with increasing age, resulted in the loss of clustered NMJ Na+ channels. Together, our results suggest that muscle ß1 spectrin functions independently of an associated α spectrin to maintain Na+ channel clustering at the postsynaptic NMJ. Furthermore, despite repeated exposure to strong forces and in contrast to neurons, muscles do not require spectrin cytoskeletons to maintain cell shape or integrity. KEY POINTS: The myopathy found in pathogenic human SPTBN4 variants (where SPTBN4 is the gene encoding ß4 spectrin) is neurogenic in origin. ß1 spectrin plays essential roles in maintaining the density of neuromuscular junction Nav1.4 Na+ channels. By contrast to the canonical view of spectrin organization and function, we show that ß1 spectrin can function independently of an associated α spectrin. Despite the large mechanical forces experienced by muscle, we show that spectrins are not required for muscle cell integrity. This is in stark contrast to red blood cells and the axons of neurons.
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Unión Neuromuscular , Canales de Sodio , Espectrina , Animales , Humanos , Ratones , Citoesqueleto de Actina/metabolismo , Músculo Esquelético/metabolismo , Enfermedades Musculares , Unión Neuromuscular/metabolismo , Espectrina/genética , Espectrina/análisis , Espectrina/metabolismo , Canales de Sodio/metabolismoRESUMEN
The axon initial segment (AIS) is a specialized neuronal compartment required for action potential generation and neuronal polarity. However, understanding the mechanisms regulating AIS structure and function has been hindered by an incomplete knowledge of its molecular composition. Here, using immuno-proximity biotinylation we further define the AIS proteome and its dynamic changes during neuronal maturation. Among the many AIS proteins identified, we show that SCRIB is highly enriched in the AIS both in vitro and in vivo, and exhibits a periodic architecture like the axonal spectrin-based cytoskeleton. We find that ankyrinG interacts with and recruits SCRIB to the AIS. However, loss of SCRIB has no effect on ankyrinG. This powerful and flexible approach further defines the AIS proteome and provides a rich resource to elucidate the mechanisms regulating AIS structure and function.
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Segmento Inicial del Axón , Segmento Inicial del Axón/metabolismo , Proteoma/metabolismo , Biotinilación , Axones/metabolismo , Neuronas/metabolismoRESUMEN
Axon initial segment (AIS) cell surface proteins mediate key biological processes in neurons including action potential initiation and axo-axonic synapse formation. However, few AIS cell surface proteins have been identified. Here, we use antibody-directed proximity biotinylation to define the cell surface proteins in close proximity to the AIS cell adhesion molecule Neurofascin. To determine the distributions of the identified proteins, we use CRISPR-mediated genome editing for insertion of epitope tags in the endogenous proteins. We identify Contactin-1 (Cntn1) as an AIS cell surface protein. Cntn1 is enriched at the AIS through interactions with Neurofascin and NrCAM. We further show that Cntn1 contributes to assembly of the AIS extracellular matrix, and regulates AIS axo-axonic innervation by inhibitory basket cells in the cerebellum and inhibitory chandelier cells in the cortex.
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Segmento Inicial del Axón , Fenómenos Biológicos , Segmento Inicial del Axón/metabolismo , Contactina 1/metabolismo , Biotinilación , Sinapsis/metabolismo , Axones/metabolismo , Proteínas de la Membrana/metabolismo , Anticuerpos/metabolismoRESUMEN
Oncomodulin (Ocm) is a myeloid cell-derived growth factor that enables axon regeneration in mice and rats after optic nerve injury or peripheral nerve injury, yet the mechanisms underlying its activity are unknown. Using proximity biotinylation, coimmunoprecipitation, surface plasmon resonance, and ectopic expression, we have identified armadillo-repeat protein C10 (ArmC10) as a high-affinity receptor for Ocm. ArmC10 deletion suppressed inflammation-induced axon regeneration in the injured optic nerves of mice. ArmC10 deletion also suppressed the ability of lesioned sensory neurons to regenerate peripheral axons rapidly after a second injury and to regenerate their central axons after spinal cord injury in mice (the conditioning lesion effect). Conversely, Ocm acted through ArmC10 to accelerate optic nerve and peripheral nerve regeneration and to enable spinal cord axon regeneration in these mouse nerve injury models. We showed that ArmC10 is highly expressed in human-induced pluripotent stem cell-derived sensory neurons and that exposure to Ocm altered gene expression and enhanced neurite outgrowth. ArmC10 was also expressed in human monocytes, and Ocm increased the expression of immune modulatory genes in these cells. These findings suggest that Ocm acting through its receptor ArmC10 may be a useful therapeutic target for nerve repair and immune modulation.
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Axones , Células Madre Pluripotentes Inducidas , Animales , Humanos , Ratones , Ganglios Espinales/metabolismo , Regeneración Nerviosa , Proyección Neuronal , Células Receptoras SensorialesRESUMEN
Axon initial segment (AIS) cell surface proteins mediate key biological processes in neurons including action potential initiation and axo-axonic synapse formation. However, few AIS cell surface proteins have been identified. Here, we used antibody-directed proximity biotinylation to define the cell surface proteins in close proximity to the AIS cell adhesion molecule Neurofascin. To determine the distributions of the identified proteins, we used CRISPR-mediated genome editing for insertion of epitope tags in the endogenous proteins. We found Contactin-1 (Cntn1) among the previously unknown AIS proteins we identified. Cntn1 is enriched at the AIS through interactions with Neurofascin and NrCAM. We further show that Cntn1 contributes to assembly of the AIS-extracellular matrix, and is required for AIS axo-axonic innervation by inhibitory basket cells in the cerebellum and inhibitory chandelier cells in the cortex.
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Fast synaptic inhibition is dependent on targeting specific GABAAR subtypes to dendritic and axon initial segment (AIS) synapses. Synaptic GABAARs are typically assembled from α1-3, ß and γ subunits. Here, we isolate distinct GABAARs from the brain and interrogate their composition using quantitative proteomics. We show that α2-containing receptors co-assemble with α1 subunits, whereas α1 receptors can form GABAARs with α1 as the sole α subunit. We demonstrate that α1 and α2 subunit-containing receptors co-purify with distinct spectrin isoforms; cytoskeletal proteins that link transmembrane proteins to the cytoskeleton. ß2-spectrin was preferentially associated with α1-containing GABAARs at dendritic synapses, while ß4-spectrin was associated with α2-containing GABAARs at AIS synapses. Ablating ß2-spectrin expression reduced dendritic and AIS synapses containing α1 but increased the number of synapses containing α2, which altered phasic inhibition. Thus, we demonstrate a role for spectrins in the synapse-specific targeting of GABAARs, determining the efficacy of fast neuronal inhibition.
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Receptores de GABA-A , Espectrina , Receptores de GABA-A/metabolismo , Espectrina/metabolismo , Sinapsis/metabolismo , Proteínas de la Membrana/metabolismo , Ácido gamma-Aminobutírico/metabolismoRESUMEN
The ankyrin proteins (Ankyrin-R, Ankyrin-B, and Ankyrin-G) are a family of scaffolding, or membrane adaptor proteins necessary for the regulation and targeting of several types of ion channels and membrane transporters throughout the body. These include voltage-gated sodium, potassium, and calcium channels in the nervous system, heart, lungs, and muscle. At these sites, ankyrins recruit ion channels, and other membrane proteins, to specific subcellular domains, which are then stabilized through ankyrin's interaction with the submembranous spectrin-based cytoskeleton. Several recent studies have expanded our understanding of both ankyrin expression and their ion channel binding partners. This review provides an updated overview of ankyrin proteins and their known channel and transporter interactions. We further discuss several potential avenues of future research that would expand our understanding of these important organizational proteins.
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Ancirinas , Canales Iónicos , Ancirinas/química , Ancirinas/metabolismo , Citoesqueleto/metabolismo , Canales Iónicos/metabolismo , Proteínas de la Membrana/metabolismo , Espectrina/química , Espectrina/metabolismoRESUMEN
The axon initial segment (AIS) generates action potentials and maintains neuronal polarity by regulating the differential trafficking and distribution of proteins, transport vesicles, and organelles. Injury and disease can disrupt the AIS, and the subsequent loss of clustered ion channels and polarity mechanisms may alter neuronal excitability and function. However, the impact of AIS disruption on axon regeneration after injury is unknown. We generated male and female mice with AIS-deficient multipolar motor neurons by deleting AnkyrinG, the master scaffolding protein required for AIS assembly and maintenance. We found that after nerve crush, neuromuscular junction reinnervation was significantly delayed in AIS-deficient motor neurons compared with control mice. In contrast, loss of AnkyrinG from pseudo-unipolar sensory neurons did not impair axon regeneration into the intraepidermal nerve fiber layer. Even after AIS-deficient motor neurons reinnervated the neuromuscular junction, they failed to functionally recover because of reduced synaptic vesicle protein 2 at presynaptic terminals. In addition, mRNA trafficking was disrupted in AIS-deficient axons. Our results show that, after nerve injury, an intact AIS is essential for efficient regeneration and functional recovery of axons in multipolar motor neurons. Our results also suggest that loss of polarity in AIS-deficient motor neurons impairs the delivery of axonal proteins, mRNAs, and other cargoes necessary for regeneration. Thus, therapeutic strategies for axon regeneration must consider preservation or reassembly of the AIS.SIGNIFICANCE STATEMENT Disruption of the axon initial segment is a common event after nervous system injury. For multipolar motor neurons, we show that axon initial segments are essential for axon regeneration and functional recovery after injury. Our results may help explain injuries where axon regeneration fails, and suggest strategies to promote more efficient axon regeneration.
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Segmento Inicial del Axón , Axones , Masculino , Femenino , Ratones , Animales , Axones/fisiología , Segmento Inicial del Axón/metabolismo , Ancirinas/metabolismo , Regeneración Nerviosa , Sinapsis/metabolismo , Canales Iónicos/metabolismo , Neuronas Motoras/metabolismo , ARN Mensajero/metabolismoRESUMEN
OBJECTIVE: To identify the autoantigen in 2 individuals with possible seronegative paraneoplastic neuropathy. METHODS: Serum and CSF were screened by tissue-based assay and panned for candidate autoantibodies by phage display immunoprecipitation sequencing (PhIP-Seq). The candidate antigen was validated by immunostaining knockout tissue and HEK 293T cell-based assay. RESULTS: Case 1 presented with gait instability, distal lower extremity numbness, and paresthesias after a recent diagnosis of serous uterine and fallopian carcinoma. Case 2 had a remote history of breast adenocarcinoma and presented with gait instability, distal lower extremity numbness, and paresthesias that progressed to generalized weakness. CSF and serum from both patients immunostained the axon initial segment (AIS) and node of Ranvier (NoR) of mice and enriched ßIV-spectrin by PhIP-Seq. Patient CSF and serum failed to immunostain NoRs in dorsal root sensory neurons from ßI/ßIV-deficient mice. ßIV-spectrin autoantibodies were confirmed by overexpression of AIS and nodal ßIV-spectrin isoforms Σ1 and Σ6 by a cell-based assay. ßIV-spectrin was not enriched in a combined 4,815 PhIP-Seq screens of healthy and other neurologic disease patients. DISCUSSION: Therefore, ßIV-spectrin autoantibodies may be a marker of paraneoplastic neuropathy. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that ßIV-spectrin antibodies are specific autoantibody biomarkers for paraneoplastic neuropathy.
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Polineuropatía Paraneoplásica , Espectrina , Humanos , Autoanticuerpos , Hipoestesia , Parestesia , Animales , RatonesRESUMEN
MeCP2 is associated with Rett syndrome (RTT), MECP2 duplication syndrome, and a number of conditions with isolated features of these diseases, including autism, intellectual disability, and motor dysfunction. MeCP2 is known to broadly bind methylated DNA, but the precise molecular mechanism driving disease pathogenesis remains to be determined. Using proximity-dependent biotinylation (BioID), we identified a transcription factor 20 (TCF20) complex that interacts with MeCP2 at the chromatin interface. Importantly, RTT-causing mutations in MECP2 disrupt this interaction. TCF20 and MeCP2 are highly coexpressed in neurons and coregulate the expression of key neuronal genes. Reducing Tcf20 partially rescued the behavioral deficits caused by MECP2 overexpression, demonstrating a functional relationship between MeCP2 and TCF20 in MECP2 duplication syndrome pathogenesis. We identified a patient exhibiting RTT-like neurological features with a missense mutation in the PHF14 subunit of the TCF20 complex that abolishes the MeCP2-PHF14-TCF20 interaction. Our data demonstrate the critical role of the MeCP2-TCF20 complex for brain function.
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Proteína 2 de Unión a Metil-CpG/metabolismo , Complejos Multiproteicos/metabolismo , Trastornos del Neurodesarrollo/etiología , Trastornos del Neurodesarrollo/metabolismo , Factores de Transcripción/metabolismo , Alelos , Animales , Biomarcadores , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Proteína 2 de Unión a Metil-CpG/genética , Ratones , Ratones Noqueados , Ratones Transgénicos , Modelos Biológicos , Mutación , Neuronas/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Unión Proteica , Sinapsis/metabolismo , Factores de Transcripción/genéticaRESUMEN
Ankyrin scaffolding proteins are critical for membrane domain organization and protein stabilization in many different cell types including neurons. In the cerebellum, Ankyrin-R (AnkR) is highly enriched in Purkinje neurons, granule cells, and in the cerebellar nuclei (CN). Using male and female mice with a floxed allele for Ank1 in combination with Nestin-Cre and Pcp2-Cre mice, we found that ablation of AnkR from Purkinje neurons caused ataxia, regional and progressive neurodegeneration, and altered cerebellar output. We show that AnkR interacts with the cytoskeletal protein ß3 spectrin and the potassium channel Kv3.3. Loss of AnkR reduced somatic membrane levels of ß3 spectrin and Kv3.3 in Purkinje neurons. Thus, AnkR links Kv3.3 channels to the ß3 spectrin-based cytoskeleton. Our results may help explain why mutations in ß3 spectrin and Kv3.3 both cause spinocerebellar ataxia.SIGNIFICANCE STATEMENT Ankyrin scaffolding proteins localize and stabilize ion channels in the membrane by linking them to the spectrin-based cytoskeleton. Here, we show that Ankyrin-R (AnkR) links Kv3.3 K+ channels to the ß3 spectrin-based cytoskeleton in Purkinje neurons. Loss of AnkR causes Purkinje neuron degeneration, altered cerebellar physiology, and ataxia, which is consistent with mutations in Kv3.3 and ß3 spectrin causing spinocerebellar ataxia.
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Ancirinas/metabolismo , Citoesqueleto/metabolismo , Células de Purkinje/metabolismo , Canales de Potasio Shaw/metabolismo , Espectrina/metabolismo , Animales , Supervivencia Celular/fisiología , Femenino , Masculino , Ratones , Ataxias Espinocerebelosas/genéticaRESUMEN
Neuroinvasive infection is the most common cause of meningoencephalitis in people living with human immunodeficiency virus (HIV), but autoimmune etiologies have been reported. We present the case of a 51-year-old man living with HIV infection with steroid-responsive meningoencephalitis whose comprehensive pathogen testing was non-diagnostic. Subsequent tissue-based immunofluorescence with acute-phase cerebrospinal fluid revealed anti-neural antibodies localizing to the axon initial segment (AIS), the node of Ranvier (NoR), and the subpial space. Phage display immunoprecipitation sequencing identified ankyrinG (AnkG) as the leading candidate autoantigen. A synthetic blocking peptide encoding the PhIP-Seq-identified AnkG epitope neutralized CSF IgG binding to the AIS and NoR, thereby confirming a monoepitopic AnkG antibody response. However, subpial immunostaining persisted, indicating the presence of additional autoantibodies. Review of archival tissue-based staining identified candidate AnkG autoantibodies in a 60-year-old woman with metastatic ovarian cancer and seizures that were subsequently validated by cell-based assay. AnkG antibodies were not detected by tissue-based assay and/or PhIP-Seq in control CSF (N = 39), HIV CSF (N = 79), or other suspected and confirmed neuroinflammatory CSF cases (N = 1,236). Therefore, AnkG autoantibodies in CSF are rare but extend the catalog of AIS and NoR autoantibodies associated with neurological autoimmunity.
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Accumulating evidence supports the prevalence of experience-dependent oligodendrocyte precursor cell (OPC) differentiation and myelination in learning and memory. However, the mechanisms remain unknown. In this issue of Neuron, Osso et al., (2021) report that stress causes the secretion of dynorphin by unmyelinated axons, which induces OPC differentiation and myelination of neighboring axons.
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Dinorfinas , Células Precursoras de Oligodendrocitos , Axones , Diferenciación Celular , OligodendroglíaRESUMEN
Skeletal muscle contraction depends on activation of clustered acetylcholine receptors (AchRs) and muscle-specific Na+ channels (Nav1.4). Some Nav1.4 channels are highly enriched at the neuromuscular junction (NMJ), and their clustering is thought to be essential for effective muscle excitation. However, this has not been experimentally tested, and how NMJ Na+ channels are clustered is unknown. Here, using muscle-specific ankyrinR, ankyrinB, and ankyrinG single, double, and triple-conditional knockout mice, we show that Nav1.4 channels fail to cluster only after deletion of all three ankyrins. Remarkably, ankyrin-deficient muscles have normal NMJ morphology, AchR clustering, sarcolemmal levels of Nav1.4, and muscle force, and they show no indication of degeneration. However, mice lacking clustered NMJ Na+ channels have significantly reduced levels of motor activity and their NMJs rapidly fatigue after repeated nerve-dependent stimulation. Thus, the triple redundancy of ankyrins facilitates NMJ Na+ channel clustering to prevent neuromuscular synapse fatigue.
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Ancirinas , Músculo Esquelético , Animales , Ancirinas/genética , Análisis por Conglomerados , Fatiga , Ratones , SinapsisRESUMEN
Neuronal ankyrins cluster and link membrane proteins to the actin and spectrin-based cytoskeleton. Among the three vertebrate ankyrins, little is known about neuronal Ankyrin-R (AnkR). We report AnkR is highly enriched in Pv+ fast-spiking interneurons in mouse and human. We identify AnkR-associated protein complexes including cytoskeletal proteins, cell adhesion molecules (CAMs), and perineuronal nets (PNNs). We show that loss of AnkR from forebrain interneurons reduces and disrupts PNNs, decreases anxiety-like behaviors, and changes the intrinsic excitability and firing properties of Pv+ fast-spiking interneurons. These changes are accompanied by a dramatic reduction in Kv3.1b K+ channels. We identify a novel AnkR-binding motif in Kv3.1b, and show that AnkR is both necessary and sufficient for Kv3.1b membrane localization in interneurons and at nodes of Ranvier. Thus, AnkR regulates Pv+ fast-spiking interneuron function by organizing ion channels, CAMs, and PNNs, and linking these to the underlying ß1 spectrin-based cytoskeleton.