Affinage

CTNND2

Catenin delta-2 · UniProt Q9UQB3

Length
1225 aa
Mass
132.7 kDa
Annotated
2026-06-09
31 papers in source corpus 14 papers cited in narrative 15 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 8/8 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

CTNND2 (delta-catenin/NPRAP) is a brain-enriched armadillo-repeat catenin that organizes excitatory synapses and shapes neuronal morphogenesis during cortical development (PMID:39352808, PMID:29127138). At the synapse it is a major partner of SRGAP2, where it slows synaptic maturation, supports adult synapse maintenance, and is required for retention of SYNGAP1; the human-specific protein SRGAP2C enhances its synaptic accumulation, tying CTNND2 to synaptic neoteny (PMID:39352808). It anchors AMPA receptors at excitatory synapses to regulate glutamatergic activity, and supports postsynaptic spine density and actin polymerization through an mTORC2 (Rictor) axis (PMID:34455763). Beyond the synapse, CTNND2 was first identified as a constituent of N-cadherin–based adhering junctions in the retina, associating with alpha-/beta-catenin, p120, and other junctional proteins (PMID:10413599). It directly binds and stimulates sphingosine kinase 1 (SPHK1) via its seventh-to-tenth armadillo repeats to drive cell motility (PMID:15193146), and participates in a GSK-3beta destruction complex with beta-catenin and APC to promote beta-catenin ubiquitination and turnover (PMID:20623542). CTNND2 expression is transcriptionally activated by E2F1 and repressed by Hes1 binding to promoter E-boxes (PMID:21106062). Loss-of-function disrupts neuronal migration in vivo (PMID:25473103) and impairs early neurogenesis with dysregulated WNT signaling (PMID:41502569). A missense mutation (p.Glu1044Lys) causes familial cortical myoclonic tremor and epilepsy, with mutant protein failing to rescue the neurite-outgrowth phenotype of Ctnnd2 knockdown (PMID:29127138), and hemizygous loss at 5p15.2 correlates with the neurodevelopmental features of cri-du-chat syndrome (PMID:10673328).

Mechanistic history

Synthesis pass · year-by-year structured walk · 12 steps
  1. 1999 Medium

    Establishing where CTNND2 acts, it was localized to a novel N-cadherin–based adhering junction in the retina, defining it as a junctional catenin partner.

    Evidence Immunolocalization in retinal tissue sections with multiple co-detected junctional markers

    PMID:10413599

    Open questions at the time
    • No functional consequence of junctional localization tested
    • Direct binding partners within the junction not biochemically mapped
  2. 2000 Medium

    Linking CTNND2 to disease, genomic mapping to 5p15.2 and breakpoint analysis tied hemizygous loss to the neurodevelopmental features of cri-du-chat syndrome and identified presenilin-1 as a binding partner.

    Evidence Genomic mapping and patient breakpoint characterization with genotype-phenotype correlation

    PMID:10673328

    Open questions at the time
    • Presenilin-1 interaction not reconstituted in vitro
    • Causality of CTNND2 loss vs. other 5p genes not isolated
  3. 2004 High

    Defining a motility mechanism, CTNND2 was shown to directly bind and activate SPHK1 through specific armadillo repeats, with kinase activity required for CTNND2-induced cell motility.

    Evidence Yeast two-hybrid, co-IP domain mapping, purified kinase activation assay, and pharmacological SPHK1 inhibition in MDCK cells

    PMID:15193146

    Open questions at the time
    • Mechanism of SPHK1 activation not structurally resolved
    • Relevance to neuronal motility not directly tested
  4. 2008 Medium

    Addressing how CTNND2 is dysregulated in cancer, a somatic 5'-UTR mutation in prostate cancer was found to raise delta-catenin levels translationally rather than transcriptionally.

    Evidence Laser capture microdissection, SSCP, and chimeric luciferase reporter assays

    PMID:18978817

    Open questions at the time
    • Downstream oncogenic consequence of elevated CTNND2 not established
    • Single-lab finding
  5. 2010 Medium

    Two studies defined CTNND2's role in WNT/catenin homeostasis and its transcriptional control: it joins a GSK-3beta destruction complex promoting beta-catenin turnover, and its expression is activated by E2F1 yet repressed by Hes1.

    Evidence Reciprocal co-IP, cycloheximide chase, proteasome/GSK-3beta inhibition in neurons; promoter-luciferase and E-box binding with siRNA/gamma-secretase perturbation

    PMID:20623542 PMID:21106062

    Open questions at the time
    • Direct enzymatic role of CTNND2 within the destruction complex unclear
    • Physiological context coupling transcriptional control to synaptic function not defined
  6. 2011 Medium

    Probing a nuclear function, CTNND2 was shown to translocate to the nucleus and alter gene expression, and to physically associate with dynamin 2 and other neuronal proteins.

    Evidence Overexpression, microarray, nuclear translocation assay; co-IP/mass spectrometry from SH-SY5Y cells with co-localization

    PMID:21811021 PMID:22022388

    Open questions at the time
    • Nuclear localization signal not mapped by mutagenesis
    • Functional significance of dynamin interaction untested
  7. 2014 Medium

    Demonstrating an in vivo developmental role, ctnnd2 knockdown in zebrafish caused misplacement of forebrain neurons, establishing a direct requirement in neuronal migration.

    Evidence Morpholino knockdown in zebrafish embryos with forebrain neuron position analysis

    PMID:25473103

    Open questions at the time
    • Molecular pathway driving migration defect not defined
    • Morpholino specificity not orthogonally confirmed
  8. 2017 High

    Connecting CTNND2 to a Mendelian disease, a p.Glu1044Lys mutation was shown to cause FCMTE, with the mutant failing to rescue the neurite-outgrowth phenotype of knockdown.

    Evidence Exome sequencing, shRNA knockdown with wild-type vs. mutant rescue, and postmortem Purkinje cell morphology

    PMID:29127138

    Open questions at the time
    • Biochemical defect conferred by E1044K not defined
    • Mechanism linking neurite changes to tremor/epilepsy unresolved
  9. 2021 Medium

    Defining a synaptic plasticity mechanism, Ctnnd2 knockout reduced hippocampal Rictor, actin polymerization, and spine density, placing CTNND2 upstream of an mTORC2 axis controlling spatial cognition.

    Evidence Ctnnd2 KO mice, Morris water maze, Golgi staining, and Rictor shRNA epistasis

    PMID:34455763

    Open questions at the time
    • Direct biochemical link between CTNND2 and Rictor not shown
    • Single-lab finding
  10. 2024 High

    Identifying CTNND2's principal synaptic role, it was shown to partner SRGAP2 to slow synaptic maturation and maintain synapses, retain SYNGAP1, and be amplified at human synapses by SRGAP2C.

    Evidence Reciprocal co-IP, synaptic fractionation, loss-of-function phenotyping, and SRGAP2C gain-of-function in human neurons

    PMID:39352808

    Open questions at the time
    • Structural basis of SRGAP2–CTNND2 interaction unresolved
    • Mechanism by which CTNND2 loss depletes SYNGAP1 not detailed
  11. 2025 Medium

    Extending CTNND2 to epithelial biology, TMEM97 was shown to suppress CTNND2 levels, with CTNND2 driving ADAM10 expression and partial EMT in retinal pigment epithelial cells.

    Evidence TMEM97 KO and re-expression in ARPE19 cells with integrated proteomics and transcriptomics

    PMID:39995975

    Open questions at the time
    • Mechanism of TMEM97-dependent CTNND2 regulation unknown
    • Relevance to in vivo RPE pathology untested
  12. 2025 Medium

    Two models refined CTNND2's developmental and synaptic roles: loss-of-function disrupted early neurogenesis via dysregulated WNT signaling, and haploinsufficiency reduced synaptic AMPA receptor anchoring with social and fear-learning deficits.

    Evidence Patient-derived NSC/CRISPR KO lines with WNT modulation rescue (preprint); heterozygous KO and G34S knock-in mice with synaptic biochemistry and behavior (preprint)

    PMID:41502569

    Open questions at the time
    • Both findings from preprints not yet peer-reviewed
    • Direct mechanism coupling CTNND2 to WNT pathway components not defined

Open questions

Synthesis pass · forward-looking unresolved questions
  • How CTNND2's diverse activities—synaptic AMPA receptor anchoring, beta-catenin/WNT regulation, and SPHK1-driven motility—are coordinated within a single molecular framework remains unresolved.
  • No structural model integrating armadillo-repeat partner binding
  • Whether nuclear and synaptic pools represent distinct functional states is unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0008092 cytoskeletal protein binding 2 GO:0060090 molecular adaptor activity 2 GO:0098772 molecular function regulator activity 2
Localization
GO:0005829 cytosol 2 GO:0005886 plasma membrane 2 GO:0005634 nucleus 1
Pathway
R-HSA-112316 Neuronal System 2 R-HSA-1266738 Developmental Biology 2 R-HSA-162582 Signal Transduction 2
Partners
APCCDH2CTNNB1DNM2GSK3BPSEN1SPHK1SRGAP2
Complex memberships
GSK-3beta/beta-catenin/APC destruction complex

Evidence

Reading pass · 15 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1999 NPRAP/delta-catenin (CTNND2) was identified as a constituent of adherens junction plaques at the outer limiting zone (OLZ) of the retina, where it co-localizes with N-cadherin, alpha- and beta-catenin, p120, vinculin, symplekin, ZO-1, and plakophilin 2, but not plakoglobin, defining a novel type of adhering junction. Immunolocalization techniques in retinal tissue sections Experimental Cell Research Medium 10413599
2000 Delta-catenin (CTNND2) was originally discovered as a binding partner of presenilin-1 and maps to chromosome 5p15.2; hemizygous loss correlates with severe mental retardation in cri-du-chat syndrome, consistent with a neuronal-specific role in cell motility during early development. Genomic mapping, breakpoint characterization in patients with 5p deletions, genotype-phenotype correlation Genomics Medium 10673328
2004 Delta-catenin/NPRAP directly interacts with sphingosine kinase 1 (SPHK1) via its seventh-to-tenth armadillo repeats, co-localizes with SPHK1 in rat hippocampal neurons, stimulates SPHK1 enzymatic activity in a dose-dependent manner in a purified system, and SPHK1 inhibition abolishes delta-catenin-induced cell motility in MDCK cells. Yeast two-hybrid screening, co-immunoprecipitation, co-localization in neurons, in vitro purified kinase activity assay, pharmacological inhibition of SPHK1 The Biochemical Journal High 15193146
2008 A somatic point mutation (-9 G>A) in the 5'-UTR of the delta-catenin (CTNND2) gene, found in prostate cancer but not adjacent benign tissue, increases delta-catenin expression by promoting translation (not transcription), as shown by chimeric luciferase reporter assays. SSCP analysis, laser capture microdissection + PCR, chimeric luciferase reporter assays Oncogene Medium 18978817
2010 Delta-catenin/NPRAP (CTNND2) participates in the GSK-3beta destruction complex in neurons: it co-localizes and co-immunoprecipitates with GSK-3beta, beta-catenin, and APC; GSK-3beta inhibition increases delta-catenin protein levels; delta-catenin overexpression enhances GSK-3beta–beta-catenin interaction and promotes beta-catenin ubiquitination and turnover via proteasomal degradation. Co-immunoprecipitation, immunofluorescence, cycloheximide chase, proteasome inhibitor treatment, GSK-3beta pharmacological inhibition, overexpression in primary cortical neurons and PC12 cells Journal of Neuroscience Research Medium 20623542
2010 Hes1 (human homolog of Drosophila Hairy/enhancer of split) directly binds E-boxes on the delta-catenin (CTNND2) promoter and represses delta-catenin expression in cooperation with the activating transcription factor E2F1; suppression of Hes1 by gamma-secretase inhibitors or siRNA increases delta-catenin expression. Delta-catenin promoter-luciferase reporter assay, chromatin binding (E-box), siRNA knockdown, gamma-secretase inhibitors, cell line analysis Molecular Cancer Medium 21106062
2011 NPRAP/delta-catenin (CTNND2) undergoes nuclear translocation and regulates gene expression in a nuclear-localization-dependent manner, including upregulation of BCHE (linked to Alzheimer's disease), as demonstrated by overexpression, microarray, and localization experiments. Overexpression, microarray gene expression profiling, nuclear translocation assay Journal of Alzheimer's Disease Low 21811021
2011 NPRAP/delta-catenin (CTNND2) directly interacts with dynamin 2 (and also dynamin 1) as identified by co-immunoprecipitation from human SH-SY5Y cells followed by mass spectrometry, with co-localization confirmed in vivo; additional novel interactors include neurofilament alpha-internexin and IRF2 binding factors. Co-immunoprecipitation from SH-SY5Y cells, mass spectrometry, co-localization PLoS ONE Medium 22022388
2014 Morpholino knockdown of ctnnd2 in zebrafish embryos causes misplacement of a subpopulation of forebrain neurons between the diencephalon and telencephalon, demonstrating a direct role for CTNND2 in neuronal migration in vivo. Morpholino knockdown in zebrafish, analysis of neuronal position in forebrain Journal of Medical Genetics Medium 25473103
2017 A missense mutation p.Glu1044Lys in CTNND2 causes familial cortical myoclonic tremor and epilepsy (FCMTE); knockdown of Ctnnd2 in cortical mouse neurons increases neurite outgrowth, rescued by wild-type but not mutant CTNND2, mirroring morphological abnormalities observed in postmortem FCMTE patient Purkinje cells. Exome sequencing, shRNA knockdown in cortical mouse neurons, rescue with wild-type vs. mutant overexpression, postmortem brain morphology analysis Neurology High 29127138
2021 Ctnnd2 knockout mice show decreased hippocampal Rictor (mTORC2 component) expression, reduced actin polymerization, and decreased postsynaptic spine density in CA1 neurons; shRNA-mediated Rictor knockdown exacerbates spatial learning/memory deficits in both KO and wild-type mice, implicating the CTNND2–Rictor–mTORC2 axis in synaptic plasticity and spatial cognition. Ctnnd2 knockout mouse (exon 2 deletion), Morris water maze, Golgi staining, shRNA hippocampal injection, Western blotting Frontiers in Bioscience Medium 34455763
2024 CTNND2 is a major synaptic partner of SRGAP2; it slows synaptic maturation and promotes neuronal integrity during postnatal development, moderates neuronal excitation/excitability, and supports adult synapse maintenance. CTNND2 deficiency causes synaptic loss of SYNGAP1, and the human-specific protein SRGAP2C enhances CTNND2 synaptic accumulation in human neurons, linking CTNND2 regulation to synaptic neoteny. Co-immunoprecipitation, synaptic fractionation, knockdown/knockout with synaptic phenotyping, human neuron overexpression of SRGAP2C Cell Reports High 39352808
2025 TMEM97 negatively regulates CTNND2 protein levels in retinal pigment epithelial (RPE) cells; CTNND2 in turn promotes ADAM10 expression, sustaining both E-cadherin and N-cadherin levels and driving partial epithelial-mesenchymal transition (pEMT) in RPE cells. TMEM97 knockout in ARPE19 cells, subretinal lentiviral re-expression, integrated proteomics, transcriptomics, immunoblotting Molecular Therapy: Nucleic Acids Medium 39995975
2025 Loss-of-function variants in CTNND2 impair early neurogenesis in patient-derived neural stem cells, causing aberrant neural rosette formation; transcriptomic profiling reveals dysregulated WNT signaling, and pharmacological WNT pathway modulation partially rescues these defects, establishing delta-catenin as a regulator of WNT signaling during early neural development. Patient-derived neural stem cells, CRISPR-Cas9 CTNND2 knockout lines, neural differentiation, transcriptomic profiling, cerebral organoid development, WNT pathway modulation rescue experiment Research Square (preprint)preprint Medium 41502569
2025 Delta-catenin (CTNND2) haploinsufficiency (heterozygous KO or G34S missense) in mice reduces synaptic delta-catenin and AMPA receptor levels in brain extracts and disrupts social behavior and fear learning; homozygous KO previously established that delta-catenin anchors AMPA receptors at excitatory synapses to regulate glutamatergic activity. Heterozygous delta-catenin KO and G34S knock-in mice, multiple behavioral assays (social interaction, contextual fear conditioning, open field), biochemical assay of synaptic fractions bioRxiv (preprint)preprint Medium

Source papers

Stage 0 corpus · 31 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2000 Hemizygosity of delta-catenin (CTNND2) is associated with severe mental retardation in cri-du-chat syndrome. Genomics 136 10673328
2010 Genome-wide association studies reveal genetic variants in CTNND2 for high myopia in Singapore Chinese. Ophthalmology 109 21095009
1999 The arm-repeat protein NPRAP (neurojungin) is a constituent of the plaques of the outer limiting zone in the retina, defining a novel type of adhering junction. Experimental cell research 75 10413599
2013 Further confirmation of the association between anxiety and CTNND2: replication in humans. Genes, brain, and behavior 45 24256404
2004 Delta-catenin/NPRAP (neural plakophilin-related armadillo repeat protein) interacts with and activates sphingosine kinase 1. The Biochemical journal 43 15193146
2019 Hypoxia-induced lncRNA EIF3J-AS1 accelerates hepatocellular carcinoma progression via targeting miR-122-5p/CTNND2 axis. Biochemical and biophysical research communications 40 31421822
2016 Genetic alterations of δ-catenin/NPRAP/Neurojungin (CTNND2): functional implications in complex human diseases. Human genetics 39 27380241
2011 Replication study supports CTNND2 as a susceptibility gene for high myopia. Investigative ophthalmology & visual science 38 21911587
2008 Increased nucleotide polymorphic changes in the 5'-untranslated region of delta-catenin (CTNND2) gene in prostate cancer. Oncogene 36 18978817
2014 CTNND2-a candidate gene for reading problems and mild intellectual disability. Journal of medical genetics 33 25473103
2010 Delta-catenin/NPRAP: A new member of the glycogen synthase kinase-3beta signaling complex that promotes beta-catenin turnover in neurons. Journal of neuroscience research 29 20623542
2014 Amelioration of the typical cognitive phenotype in a patient with the 5pter deletion associated with Cri-du-chat syndrome in addition to a partial duplication of CTNND2. American journal of medical genetics. Part A 23 24677774
2017 δ-Catenin (CTNND2) missense mutation in familial cortical myoclonic tremor and epilepsy. Neurology 21 29127138
2024 CTNND2 moderates the pace of synaptic maturation and links human evolution to synaptic neoteny. Cell reports 20 39352808
2012 Polymorphisms in the CTNND2 gene and 11q24.1 genomic region are associated with pathological myopia in a Chinese population. Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift fur Augenheilkunde 19 22759899
2020 Disruption of CTNND2, encoding delta-catenin, causes a penetrant attention deficit disorder and myopia. HGG advances 17 33718894
2020 Analysis of Anti-RNA Polymerase III Antibody-positive Systemic Sclerosis and Altered GPATCH2L and CTNND2 Expression in Scleroderma Renal Crisis. The Journal of rheumatology 16 32173657
2010 Human homolog of Drosophila Hairy and enhancer of split 1, Hes1, negatively regulates δ-catenin (CTNND2) expression in cooperation with E2F1 in prostate cancer. Molecular cancer 15 21106062
2021 Rictor is involved in Ctnnd2 deletion-induced impairment of spatial learning and memory but not autism-like behaviors. Frontiers in bioscience (Landmark edition) 12 34455763
2023 Melatonin ameliorates sleep-wake disturbances and autism-like behaviors in the Ctnnd2 knock out mouse model of autism spectrum disorders. Genes, brain, and behavior 11 37278348
2011 A nuclear function for the presenilin 1 neuronal partner NPRAP/δ-catenin. Journal of Alzheimer's disease : JAD 10 21811021
2020 Novel CTNND2-TERT fusion in a spindle cell liposarcoma. Genes, chromosomes & cancer 9 32352179
2011 Identification of novel NPRAP/δ-catenin-interacting proteins and the direct association of NPRAP with dynamin 2. PloS one 8 22022388
2019 Insulin Sensitivity Is Associated with Lipoprotein Lipase (LPL) and Catenin Delta 2 (CTNND2) DNA Methylation in Peripheral White Blood Cells in Non-Diabetic Young Women. International journal of molecular sciences 7 31208038
2014 [Association of ZNF644, GRM6 and CTNND2 genes polymorphisms with high myopia]. Zhonghua yi xue za zhi 4 25142846
2025 TMEM97 governs partial epithelial-mesenchymal transition of retinal pigment epithelial cells via the CTNND2-ADAM10 axis. Molecular therapy. Nucleic acids 3 39995975
2023 Association of CTNND2 gene polymorphism with schizophrenia: Two-sample case-control study in Chinese Han population. International journal of psychiatry in medicine 3 36930964
2023 Effects of chronic sleep restriction on the neuro-phenotypes of Ctnnd2 knockout mice. Brain and behavior 3 37226399
2025 MiR-218 Exhibits Anti-Leukemia Effects by Targeting CTNND2 in Primary Acute Erythroid Leukemia HEL Cells. Cell biochemistry and biophysics 1 40100342
2026 Ceritinib efficacy in SMARCA4-deficient NSCLC harboring novel CTNND2 ALK/EML4-ALK fusion: case report. Frontiers in oncology 0 41684594
2025 Characterization of CTNND2-related neurodevelopmental disease, phenotype-genotype spectrum and WNT dynamics in early neurogenesis. Research square 0 41502569

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