Affinage

SLITRK3

SLIT and NTRK-like protein 3 · UniProt O94933

Length
977 aa
Mass
108.9 kDa
Annotated
2026-06-10
19 papers in source corpus 9 papers cited in narrative 9 extracted findings
Cross-family judge faithfulness: 5/6 claims corpus-supported (83%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

SLITRK3 is a postsynaptic single-pass transmembrane adhesion molecule that selectively organizes inhibitory (GABAergic) synapses in the brain (PMID:22286174, PMID:14557068). Through its extracellular domains it engages the axonal receptor protein tyrosine phosphatase PTPδ in trans to drive inhibitory presynaptic differentiation, and SLITRK3-deficient neurons show reduced inhibitory synapse number and function with increased seizure susceptibility (PMID:22286174). SLITRK3 acts within a larger inhibitory synaptic organizing assembly: it binds Neuroligin 2 in cis with nanomolar affinity to synergistically promote mature GABAergic synapse development (PMID:29107521), interacts in trans with the ErbB4 extracellular RLD domain to promote inhibitory synapse formation onto pyramidal neurons independently of ErbB4 kinase activity (PMID:34226493), and associates with gephyrin as part of postsynaptic stabilization (PMID:34735259). Trans-synaptic complex formation with LAR-RPTPs proceeds via reciprocal higher-order clustering that can be dismantled by competing heparan sulfate (PMID:29081732). A conserved intracellular tyrosine, Y969, is dispensable for surface trafficking and homodimerization but required for GABAergic synapse development and transmission (PMID:31551708). Biallelic loss-of-function variants in SLITRK3 cause epileptic encephalopathy, with patient mutations causing Golgi accumulation and reduced surface expression, diminished GABAergic transmission in neurons, and spontaneous epileptiform activity with loss of parvalbumin interneurons in knockout mice (PMID:38495551).

Mechanistic history

Synthesis pass · year-by-year structured walk · 9 steps
  1. 2003 Medium

    Established SLITRK3's protein architecture and tissue distribution, framing it as a candidate brain adhesion/signaling molecule before any synaptic function was known.

    Evidence Genomic and domain characterization with brain-enriched expression profiling

    PMID:14557068

    Open questions at the time
    • No functional or synaptic role tested
    • Binding partners unidentified
  2. 2012 High

    Resolved what SLITRK3 actually does — it is a postsynaptic organizer that selectively induces GABAergic, not excitatory, presynaptic differentiation via trans-synaptic PTPδ binding, linking it to seizure phenotypes.

    Evidence Heterologous synaptogenesis (fibroblast co-culture), knockout mouse electrophysiology/EEG, trans-interaction assay with PTPδ

    PMID:22286174

    Open questions at the time
    • Postsynaptic cis-partners not yet defined
    • Intracellular signaling requirements unknown
  3. 2017 High

    Identified a postsynaptic cis-partnership — SLITRK3 binds Neuroligin 2 with nanomolar affinity, showing the two cooperate to build mature inhibitory synapses rather than acting independently.

    Evidence Co-immunoprecipitation, binding affinity measurement, genetic perturbation in hippocampal neurons, electrophysiology and seizure assays

    PMID:29107521

    Open questions at the time
    • Stoichiometry of NL2-ST3-PTPδ assembly unresolved
    • How cis and trans interactions are coordinated unclear
  4. 2017 Medium

    Provided structural logic for trans-synaptic assembly, showing LAR-RPTP/SLITRK3 complexes form higher-order clusters that heparan sulfate can competitively disassemble, implying a regulated switch.

    Evidence Crystal structure of related LAR-RPTP/IL1RAPL1 complex, clustering and competitive binding assays

    PMID:29081732

    Open questions at the time
    • SLITRK3-specific structural data inferred from related complex
    • Physiological trigger for heparan sulfate competition not established
  5. 2019 High

    Localized the functional requirement to a specific intracellular residue — Y969 is needed for GABAergic synapse development and gephyrin clustering but not for trafficking or dimerization, separating signaling from adhesion functions.

    Evidence Site-directed mutagenesis with rescue, electrophysiology, gephyrin immunostaining, surface trafficking assay

    PMID:31551708

    Open questions at the time
    • Whether Y969 is phosphorylated and by which kinase not shown
    • Intracellular effectors binding Y969 unidentified
  6. 2021 High

    Added a second trans-synaptic partner, ErbB4, acting through its RLD domain independent of kinase activity, broadening the receptor repertoire driving inhibitory synapse formation.

    Evidence Co-IP/pulldown, domain-deletion synaptogenesis assay, kinase-dead knock-in mice, electrophysiology

    PMID:34226493

    Open questions at the time
    • How ErbB4 and PTPδ trans-interactions are coordinated unclear
    • Cell-type specificity of each partner not fully mapped
  7. 2021 Medium

    Placed SLITRK3 in a postsynaptic stabilization mechanism by linking it to gephyrin downstream of A2A/GABAAR signaling and PKA-mediated gephyrin phosphorylation.

    Evidence Co-IP of gephyrin and SLITRK3, gephyrin S303 phosphorylation mutagenesis, pharmacology, live imaging

    PMID:34735259

    Open questions at the time
    • SLITRK3-gephyrin binding evidence partially inferred
    • Direct vs. indirect association not resolved
  8. 2021 Low

    Reported a distinct disease context in which SLITRK3 amplification activates NTRK3 to promote a cancer stem cell phenotype in lung squamous carcinoma.

    Evidence Immunofluorescence, sphere-formation and CD133+ FACS assays, NTRK inhibitor treatment in LUSC lines

    PMID:35006496

    Open questions at the time
    • Direct SLITRK3-NTRK3 interaction not demonstrated biochemically
    • Single-lab, indirect activation inference
    • Relevance to neuronal NTRK signaling untested
  9. 2024 High

    Established SLITRK3 as a human disease gene — biallelic loss-of-function causes epileptic encephalopathy through Golgi retention, loss of surface expression, and reduced GABAergic transmission, recapitulated by knockout mouse phenotypes.

    Evidence Patient-derived neuron electrophysiology, HEK surface/Golgi localization imaging, KO mouse EEG and behavior

    PMID:38495551

    Open questions at the time
    • Whether all patient variants act via the same trafficking defect unknown
    • Parvalbumin interneuron loss mechanism not dissected

Open questions

Synthesis pass · forward-looking unresolved questions
  • How SLITRK3 coordinates its multiple cis (NL2) and trans (PTPδ, ErbB4) partners and how Y969 transduces an intracellular signal to gephyrin remain unresolved.
  • No identified kinase or effector acting on Y969
  • Stoichiometry/order of multi-partner assembly unknown
  • Structural model of the full postsynaptic complex absent

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0098631 cell adhesion mediator activity 3 GO:0060089 molecular transducer activity 1
Localization
GO:0005886 plasma membrane 3 GO:0005794 Golgi apparatus 1
Pathway
R-HSA-112316 Neuronal System 2 R-HSA-1266738 Developmental Biology 2
Complex memberships
trans-synaptic LAR-RPTP/SLITRK3 adhesion complex

Evidence

Reading pass · 9 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2012 Slitrk3 acts as a postsynaptic adhesion molecule that selectively induces inhibitory (GABAergic) presynaptic differentiation via trans-synaptic interaction with axonal PTPδ (receptor protein tyrosine phosphatase delta). When expressed in fibroblasts, Slitrk3 triggered only inhibitory presynaptic differentiation in contacting axons of co-cultured hippocampal neurons. Recombinant Slitrk3 preferentially localized to inhibitory postsynaptic sites. Slitrk3-deficient mice showed decreased inhibitory synapse number and function in hippocampal CA1 neurons and increased seizure susceptibility. Heterologous cell synaptogenesis assay (fibroblast co-culture), recombinant protein localization, Slitrk3 knockout mouse analysis (electrophysiology, immunostaining, EEG), trans-interaction assay with PTPδ Nature neuroscience High 22286174
2017 Slitrk3 (ST3) interacts with Neuroligin 2 (NL2) through their extracellular domains with nanomolar affinity in a cis interaction. During neuronal maturation, both NL2 and ST3 are required together for inhibitory synapse development; selective perturbation of the NL2-ST3 interaction impairs inhibitory synapse development, disrupts hippocampal network activity, and increases seizure susceptibility. NL2 is required for establishing GABAergic transmission in developing neurons, while mature inhibitory synapse development requires both NL2 and ST3 acting synergistically. Co-immunoprecipitation, binding affinity measurements, hippocampal neuron culture with genetic perturbation, electrophysiology, seizure susceptibility assays Neuron High 29107521
2019 The conserved tyrosine residue Y969 in the intracellular C-terminus of Slitrk3 is critical for GABAergic synapse development. Overexpression of the Y969A mutant markedly reduced gephyrin puncta density and GABAergic transmission in hippocampal neurons. Wild-type ST3, but not ST3 Y969A, rescued GABAergic transmission deficits in neurons lacking endogenous ST3. The C-terminus is not required for ST3 homo-dimerization or trafficking to the cell surface in heterologous cells. Site-directed mutagenesis, overexpression and rescue experiments in hippocampal neurons, electrophysiology, immunostaining for gephyrin puncta, heterologous cell surface trafficking assay Frontiers in molecular neuroscience High 31551708
2021 ErbB4 interacts in trans with Slitrk3 through the extracellular RLD domain of ErbB4 to promote inhibitory synapse formation onto pyramidal neurons independently of ErbB4 kinase activity. Deletion of the RLD domain abolished induction of gephyrin and GABAAR α1 puncta by ErbB4. Disruption of the ErbB4-Slitrk3 interaction by secretable RLD decreased inhibitory synapses and impaired GABAergic transmission. Co-immunoprecipitation/pulldown of ErbB4 and Slitrk3, heterologous cell co-culture synaptogenesis assay, domain deletion mutants, kinase-dead knock-in mice, electrophysiology Translational psychiatry High 34226493
2021 Gephyrin interacts with Slitrk3 as part of the synapse stabilization mechanism downstream of adenosine A2A receptor and GABAAR activation. PKA-mediated phosphorylation of gephyrin on serine 303 is required for GABAAR stabilization, and stabilization of pre- and postsynaptic GABAergic elements involves the gephyrin-Slitrk3 interaction. Co-immunoprecipitation of gephyrin and Slitrk3, phosphorylation site mutagenesis (gephyrin S303), pharmacological receptor activation/inhibition, live imaging of synapse stability Science (New York, N.Y.) Medium 34735259
2017 LAR-RPTP (PTPδ) binding to Slitrk3 (as well as IL1RAPL1 and IL-1RAcP) induces reciprocal higher-order clustering of trans-synaptic adhesion complexes. Crystal structure of LAR-RPTP/IL1RAPL1 complex reveals lateral interactions critical for higher-order assembly; competitive binding of heparan sulfate to LAR-RPTP can dismantle pre-established LAR-RPTP/Slitrk3 trans-synaptic complexes. Crystal structure determination, cell clustering assay, competitive binding with heparan sulfate, synaptogenesis assay in HEK cell co-culture Frontiers in molecular neuroscience Medium 29081732
2003 SLITRK3 protein is characterized as an integral membrane protein with two leucine-rich repeat (LRR) domains similar to Slit proteins and a C-terminal domain partially similar to Trk neurotrophin receptors. It is expressed predominantly in the brain. Genomic organization analysis, expression profiling (Northern blot/RT-PCR), protein domain characterization Gene Medium 14557068
2024 Biallelic loss-of-function variants in SLITRK3 (C566R and E606X) cause epileptic encephalopathy. Patient variants C566R and E606X alter SLITRK3 protein surface expression by causing accumulation in the Golgi apparatus. Primary hippocampal neuron cultures carrying patient variants show reduced GABAergic transmission (confirmed by electrophysiology). SLITRK3 KO mice exhibit spontaneous epileptiform EEG activity, enhanced pentylenetetrazole-induced seizures, increased motor activity, and reduced parvalbumin interneurons. Patient-derived neuron cultures, electrophysiology, immunostaining of HEK-293 cells (cell surface vs. Golgi localization), SLITRK3 knockout mouse EEG and behavioral analysis Frontiers in molecular neuroscience High 38495551
2021 SLITRK3 gene amplification in lung squamous cell carcinoma (LUSC) leads to SLITRK3-dependent activation of NTRK3 (TrkC), promoting a cancer stem cell phenotype. SLITRK3-dependent NTRK3 activation was demonstrated by sphere-formation assay and CD133-positive cell fraction analysis, and was inhibited by NTRK-targeted inhibitors. In situ immunofluorescence, sphere-formation assay, FACS analysis of CD133+ fraction, pharmacological inhibition of NTRK in LUSC cell lines Molecular biomedicine Low 35006496

Source papers

Stage 0 corpus · 19 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2014 Genome-wide association study in obsessive-compulsive disorder: results from the OCGAS. Molecular psychiatry 234 24821223
2012 Selective control of inhibitory synapse development by Slitrk3-PTPδ trans-synaptic interaction. Nature neuroscience 208 22286174
2003 Human SLITRK family genes: genomic organization and expression profiling in normal brain and brain tumor tissue. Gene 119 14557068
2017 Molecular Dissection of Neuroligin 2 and Slitrk3 Reveals an Essential Framework for GABAergic Synapse Development. Neuron 80 29107521
2021 Convergence of adenosine and GABA signaling for synapse stabilization during development. Science (New York, N.Y.) 67 34735259
2017 LAR-RPTP Clustering Is Modulated by Competitive Binding between Synaptic Adhesion Partners and Heparan Sulfate. Frontiers in molecular neuroscience 25 29081732
2021 ErbB4 promotes inhibitory synapse formation by cell adhesion, independent of its kinase activity. Translational psychiatry 21 34226493
2023 Cerebrospinal fluid proteomics in meningitis patients with reactivated varicella zoster virus. Immunity, inflammation and disease 14 37904697
2021 Role of novel cancer gene SLITRK3 to activate NTRK3 in squamous cell lung cancer. Molecular biomedicine 7 35006496
2016 Novel Nine-Exon AR Transcripts (Exon 1/Exon 1b/Exons 2-8) in Normal and Cancerous Breast and Prostate Cells. International journal of molecular sciences 7 28035996
2024 The Contribution of Mosaic Chromosomal Alterations to Schizophrenia. Biological psychiatry 6 38942348
2019 A Conserved Tyrosine Residue in Slitrk3 Carboxyl-Terminus Is Critical for GABAergic Synapse Development. Frontiers in molecular neuroscience 5 31551708
2024 Human mutations in SLITRK3 implicated in GABAergic synapse development in mice. Frontiers in molecular neuroscience 4 38495551
2023 Transcriptomic analysis of ovarian follicles uncovers the crucial genes relevant to follicle selection and preovulatory hierarchy in hens. Journal of animal science 4 37453139
2017 GABAergic Synaptogenesis: A Case for Cooperation. Neuron 2 29144966
2025 Exploring the early drivers of pain in Parkinson's disease. Scientific reports 1 39979466
2024 New insights into potential biomarkers and their roles in biological processes associated with hepatitis C-related liver cirrhosis by hepatic RNA-seq-based transcriptome profiling. Virus research 1 39216827
2025 Endometriosis: From Genes to Global Burden. International journal of molecular sciences 0 41516028
2024 Advancement in medical treatment for gastrointestinal stromal tumors (GISTs): a ray of hope. Annals of medicine and surgery (2012) 0 40213228

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