Affinage

SLITRK3

SLIT and NTRK-like protein 3 · UniProt O94933

Round 2 corrected
Length
977 aa
Mass
108.9 kDa
Annotated
2026-04-28
40 papers in source corpus 10 papers cited in narrative 10 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

SLITRK3 is a postsynaptic transmembrane adhesion molecule that selectively promotes GABAergic (inhibitory) synapse development and maintenance. Its extracellular leucine-rich repeat domains engage presynaptic PTPδ in trans to trigger inhibitory presynaptic differentiation, while a cis-interaction with Neuroligin 2 at nanomolar affinity synergistically drives inhibitory synapse assembly; heparan sulfate can competitively dismantle the PTPδ–SLITRK3 complex, and ErbB4 provides an additional trans-synaptic input that promotes inhibitory synaptogenesis onto pyramidal neurons (PMID:22286174, PMID:23345436, PMID:29107521, PMID:34226493, PMID:29081732). Intracellularly, the conserved tyrosine Y969 is required for GABAergic transmission and gephyrin scaffold stabilization, linking activity-dependent PKA-mediated gephyrin phosphorylation to the maintenance of both pre- and postsynaptic inhibitory elements (PMID:31551708, PMID:34735259). Biallelic loss-of-function SLITRK3 variants cause epileptic encephalopathy with microcephaly, consistent with impaired GABAergic transmission and reduced parvalbumin interneuron numbers observed in SLITRK3 knockout mice (PMID:38495551).

Mechanistic history

Synthesis pass · year-by-year structured walk · 7 steps
  1. 2003 Medium

    Identification of SLITRK3 as a neuronal transmembrane protein with Slit-like LRR and Trk-like intracellular domains established that the Slitrk family can regulate neurite outgrowth, with functional specificity mapping to the intracellular domain.

    Evidence Overexpression and deletion analysis in cultured neuronal cells

    PMID:14550773

    Open questions at the time
    • Neurite outgrowth phenotype was shown for Slitrk2 primarily; SLITRK3-specific effect inferred from family membership
    • Synaptic role not yet explored
    • Endogenous binding partners unknown
  2. 2012 High

    The discovery that SLITRK3 selectively promotes inhibitory synapse formation via trans-synaptic interaction with PTPδ, and that knockout mice show reduced inhibitory synapses and seizure susceptibility, established SLITRK3 as the first synapse organizer with specificity for inhibitory synapses.

    Evidence Heterologous co-culture synaptogenesis assay, immunostaining, Slitrk3 KO mice, electrophysiology

    PMID:22286174

    Open questions at the time
    • Structural basis of PTPδ selectivity unresolved
    • Postsynaptic signaling downstream of SLITRK3 unknown
    • Whether other postsynaptic partners contribute not tested
  3. 2013 High

    Independent confirmation that SLITRK3 specifically requires PTPδ (not PTPσ) for inhibitory synaptogenesis, combined with the finding that Slitrks are enriched in postsynaptic densities, solidified the isoform-specific LAR-RPTP pairing model for excitatory versus inhibitory synapse specification.

    Evidence Subcellular fractionation, overexpression/RNAi in neurons, co-culture with LAR-RPTP isoforms

    PMID:23345436

    Open questions at the time
    • Molecular determinants within PTPδ that confer SLITRK3 specificity not mapped
    • Role of PTPδ phosphatase activity in downstream signaling unclear
  4. 2017 High

    Two advances revealed the combinatorial logic of inhibitory synapse assembly: SLITRK3 forms a cis-complex with Neuroligin 2 that synergistically drives GABAergic synaptogenesis, and the trans-synaptic LAR-RPTP–ligand complexes undergo higher-order clustering essential for synaptogenic activity, with heparan sulfate capable of dismantling SLITRK3–PTPδ complexes.

    Evidence Binding affinity measurements, co-immunoprecipitation, hippocampal neuron cultures, electrophysiology, in vivo seizure testing, crystal structure and clustering assays

    PMID:29081732 PMID:29107521

    Open questions at the time
    • Structural basis of the NL2–SLITRK3 cis-interaction not determined
    • In vivo relevance of heparan sulfate-mediated complex disassembly untested
    • Stoichiometry and dynamics of higher-order assemblies at native synapses unknown
  5. 2019 High

    Identification of Y969 as a critical intracellular residue for GABAergic synapse function linked SLITRK3's postsynaptic signaling capacity to gephyrin scaffold assembly, showing the C-terminus is dispensable for surface trafficking but essential for synaptic rescue.

    Evidence Site-directed mutagenesis, single-cell KO rescue in hippocampal neurons, electrophysiology, immunostaining

    PMID:31551708

    Open questions at the time
    • Kinase responsible for Y969 phosphorylation not identified
    • Direct binding partners of the SLITRK3 intracellular domain beyond gephyrin not characterized
  6. 2021 Medium

    Three parallel discoveries expanded the SLITRK3 interaction network and its regulation: gephyrin–SLITRK3 interaction stabilizes GABAergic synapses downstream of PKA-mediated gephyrin S303 phosphorylation; ErbB4 provides a kinase-independent trans-synaptic input through its RLD domain to promote inhibitory synaptogenesis; and in a non-neuronal context, SLITRK3 gene amplification in lung squamous cell carcinoma activates NTRK3 to support a cancer stem cell phenotype.

    Evidence Pharmacological and phosphomutant assays for gephyrin interaction; co-culture, co-IP, kinase-dead knock-in mice for ErbB4; sphere-formation and FACS for cancer phenotype

    PMID:34226493 PMID:34735259 PMID:35006496

    Open questions at the time
    • Gephyrin–SLITRK3 binding interface not structurally resolved
    • ErbB4–SLITRK3 interaction confirmed in single lab; reciprocal in vivo genetic validation pending
    • NTRK3 activation mechanism by SLITRK3 in cancer cells not biochemically defined; single study with low mechanistic resolution
  7. 2024 High

    Biallelic SLITRK3 loss-of-function variants (C566R, E606X) were shown to cause epileptic encephalopathy with microcephaly, directly linking impaired SLITRK3 surface trafficking and GABAergic transmission deficits to human disease; KO mice recapitulated epileptiform activity and reduced parvalbumin interneuron numbers.

    Evidence Patient variant functional characterization in HEK-293 cells and primary neurons, mIPSC recording, EEG in KO mice, PTZ seizure threshold assay

    PMID:38495551

    Open questions at the time
    • Number of patient families is small; broader genotype–phenotype spectrum not yet defined
    • Whether C566R retains partial function or is fully null not resolved
    • Mechanism linking SLITRK3 loss to reduced parvalbumin interneuron count (cell death vs. differentiation failure) unknown

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include the identity of the kinase(s) phosphorylating Y969, the structural basis of the NL2–SLITRK3 cis-complex, how SLITRK3 signals intracellularly to recruit gephyrin, and whether therapeutic rescue of GABAergic transmission is feasible in SLITRK3-associated epileptic encephalopathy.
  • No kinase for Y969 identified
  • No crystal or cryo-EM structure of SLITRK3 intracellular domain or NL2–SLITRK3 cis-complex
  • Therapeutic strategies for SLITRK3 deficiency not explored

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0098631 cell adhesion mediator activity 3
Localization
GO:0005886 plasma membrane 4 GO:0005794 Golgi apparatus 1
Pathway
R-HSA-112316 Neuronal System 5 R-HSA-1500931 Cell-Cell communication 3 R-HSA-162582 Signal Transduction 3
Partners
ERBB4GPHNNLGN2PTPRD

Evidence

Reading pass · 10 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2012 Slitrk3 functions as a postsynaptic adhesion molecule that selectively regulates inhibitory synapse development through trans-synaptic interaction with axonal PTPδ. When expressed in fibroblasts, Slitrk3 triggered inhibitory presynaptic differentiation in contacting axons. Recombinant Slitrk3 preferentially localized to inhibitory postsynaptic sites. Slitrk3-deficient mice showed decreased inhibitory (but not excitatory) synapse number and function in hippocampal CA1 neurons, and increased seizure susceptibility. Heterologous cell co-culture synaptogenesis assay, immunostaining, Slitrk3 KO mouse analysis, electrophysiology, recombinant protein localization Nature neuroscience High 22286174
2003 Slitrk3, as a member of the Slitrk family, is an integral membrane protein with two extracellular leucine-rich repeat (LRR) domains homologous to Slit proteins and an intracellular domain partially homologous to Trk neurotrophin receptors. Overexpression of Slitrk2 and other Slitrk proteins (including Slitrk3) inhibited neurite outgrowth in cultured neuronal cells, with the functional difference between Slitrk1 and Slitrk2–6 residing in their intracellular domains. Overexpression in cultured neuronal cells, deletion analysis of intracellular domains, domain homology characterization Molecular and cellular neurosciences Medium 14550773
2013 Slitrks, including Slitrk3, are enriched in postsynaptic densities in rat brains. Slitrk3 requires PTPδ (not PTPσ) to trigger inhibitory synapse formation, establishing isoform-specific LAR-RPTP pairing: PTPσ mediates excitatory and PTPδ mediates inhibitory synaptogenesis by Slitrks. RNAi-mediated knockdown of Slitrks decreased synapse density. Subcellular fractionation, overexpression/RNAi knockdown in neurons, co-culture synaptogenesis assay with LAR-RPTP isoforms Proceedings of the National Academy of Sciences of the United States of America High 23345436
2017 Neuroligin 2 (NL2) and Slitrk3 (ST3) interact directly through their extracellular domains with nanomolar affinity in a cis fashion at postsynaptic inhibitory sites. During neuronal maturation, both NL2 and ST3 are required and act synergistically to promote GABAergic synapse development. Selective perturbation of the NL2-ST3 interaction impairs inhibitory synapse development, disrupts hippocampal network activity, and increases seizure susceptibility. Binding affinity measurements, co-immunoprecipitation, hippocampal neuron culture assays, electrophysiology, in vivo seizure susceptibility testing Neuron High 29107521
2017 LAR-RPTP binding to postsynaptic adhesion ligands including Slitrk3 induces reciprocal higher-order clustering of trans-synaptic adhesion complexes. The crystal structure of the human LAR-RPTP/IL1RAPL1 complex revealed that lateral interactions between neighboring complexes are critical for higher-order assembly and synaptogenic activity. Heparan sulfate (HS) can competitively dismantle pre-established LAR-RPTP–Slitrk3 trans-synaptic complexes. Crystal structure determination, synaptogenesis assay, clustering assay Frontiers in molecular neuroscience Medium 29081732
2019 The conserved tyrosine residue Y969 in the Slitrk3 carboxyl (C)-terminus is critical for GABAergic synapse development in hippocampal neurons. ST3 C-terminus is not required for homo-dimerization or cell-surface trafficking in heterologous cells. In neurons, the Y969A mutant failed to rescue GABAergic transmission deficits in ST3-deleted neurons and markedly reduced gephyrin puncta density. Site-directed mutagenesis, overexpression in hippocampal neurons, single-cell genetic deletion (rescue experiment), electrophysiology, immunostaining Frontiers in molecular neuroscience High 31551708
2021 Slitrk3 stabilization at GABAergic synapses during development requires interaction with gephyrin. Protein kinase A–mediated phosphorylation of gephyrin on serine 303 (downstream of GABAAR and A2AR signaling) is required for GABAAR stabilization, and gephyrin–Slitrk3 interaction is involved in the stabilization of both pre- and postsynaptic GABAergic elements. Pharmacological activation/blockade of GABAAR and A2AR, biochemical interaction assays, phosphomutant analysis, imaging of synapse stabilization/elimination Science (New York, N.Y.) Medium 34735259
2021 ErbB4, via its extracellular RLD domain, interacts in trans with Slitrk3 at inhibitory synapses in a kinase-independent manner to promote inhibitory synapse formation onto pyramidal neurons. Disruption of ErbB4-Slitrk3 interaction (using secretable RLD) decreased inhibitory synapses onto pyramidal neurons and impaired GABAergic transmission. Co-culture HEK293T/neuron synaptogenesis assay, co-immunoprecipitation, kinase-dead knock-in mice, neutralization with secretable RLD domain, electrophysiology Translational psychiatry Medium 34226493
2021 SLITRK3 activates NTRK3 in lung squamous cell carcinoma (LUSC) cells to promote a cancer stem cell phenotype. Gene amplification drives high SLITRK3 expression in LUSC, and SLITRK3-dependent NTRK3 activation is inhibited by NTRK-targeted inhibitors, reducing the CD133-positive cancer stem cell fraction. In situ immunofluorescence, sphere-formation assay, FACS (CD133+ fraction), copy number and expression analysis of patient datasets Molecular biomedicine Low 35006496
2024 Biallelic loss-of-function variants (C566R, E606X) in SLITRK3 cause epileptic encephalopathy with microcephaly, intellectual disability, and seizures. C566R and E606X mutations alter SLITRK3 cell-surface expression, causing protein accumulation in the Golgi apparatus. Primary hippocampal neurons carrying patient variants show impaired GABAergic transmission by electrophysiology. SLITRK3 KO mice exhibit spontaneous epileptiform EEG activity, enhanced seizure susceptibility, and reduced parvalbumin interneurons. Immunostaining in HEK-293 cells, primary hippocampal neuron cultures with patient variants, electrophysiology (mIPSC recording), EEG recording in KO mice, pentylenetetrazole seizure threshold assay Frontiers in molecular neuroscience High 38495551

Source papers

Stage 0 corpus · 40 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2002 Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. Proceedings of the National Academy of Sciences of the United States of America 1479 12477932
2021 Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. Cell 705 33961781
2011 Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium. Briefings in bioinformatics 656 21873635
2005 Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes. Genome research 409 16344560
2016 Proteomic Analysis of Unbounded Cellular Compartments: Synaptic Clefts. Cell 333 27565350
2017 Genome-wide CRISPR screen identifies HNRNPL as a prostate cancer dependency regulating RNA splicing. Proceedings of the National Academy of Sciences of the United States of America 282 28611215
2014 Genome-wide association study in obsessive-compulsive disorder: results from the OCGAS. Molecular psychiatry 230 24821223
2012 Selective control of inhibitory synapse development by Slitrk3-PTPδ trans-synaptic interaction. Nature neuroscience 206 22286174
1998 Prediction of the coding sequences of unidentified human genes. XII. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro. DNA research : an international journal for rapid publication of reports on genes and genomes 190 10048485
2003 Identification and characterization of Slitrk, a novel neuronal transmembrane protein family controlling neurite outgrowth. Molecular and cellular neurosciences 183 14550773
2013 Slitrks control excitatory and inhibitory synapse formation with LAR receptor protein tyrosine phosphatases. Proceedings of the National Academy of Sciences of the United States of America 155 23345436
2019 Mapping the proximity interaction network of the Rho-family GTPases reveals signalling pathways and regulatory mechanisms. Nature cell biology 137 31871319
2019 The Functional Proximal Proteome of Oncogenic Ras Includes mTORC2. Molecular cell 124 30639242
2003 Human SLITRK family genes: genomic organization and expression profiling in normal brain and brain tumor tissue. Gene 119 14557068
2017 A Global Analysis of the Receptor Tyrosine Kinase-Protein Phosphatase Interactome. Molecular cell 102 28065597
2018 Histone Interaction Landscapes Visualized by Crosslinking Mass Spectrometry in Intact Cell Nuclei. Molecular & cellular proteomics : MCP 101 30021884
2017 Molecular Dissection of Neuroligin 2 and Slitrk3 Reveals an Essential Framework for GABAergic Synapse Development. Neuron 80 29107521
2020 Interactome Mapping Provides a Network of Neurodegenerative Disease Proteins and Uncovers Widespread Protein Aggregation in Affected Brains. Cell reports 79 32814053
2010 New genetic associations detected in a host response study to hepatitis B vaccine. Genes and immunity 69 20237496
2021 Convergence of adenosine and GABA signaling for synapse stabilization during development. Science (New York, N.Y.) 67 34735259
2018 Estrogen-regulated feedback loop limits the efficacy of estrogen receptor-targeted breast cancer therapy. Proceedings of the National Academy of Sciences of the United States of America 59 29987050
2022 Physical and functional interactome atlas of human receptor tyrosine kinases. EMBO reports 50 35384245
2019 DCAF8, a novel MuRF1 interaction partner, promotes muscle atrophy. Journal of cell science 25 31391242
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
2015 SLITRK3 expression correlation to gastrointestinal stromal tumor risk rating and prognosis. World journal of gastroenterology 17 26217092
2021 SLITRK2, an X-linked modifier of the age at onset in C9orf72 frontotemporal lobar degeneration. Brain : a journal of neurology 16 34687211
2023 Cerebrospinal fluid proteomics in meningitis patients with reactivated varicella zoster virus. Immunity, inflammation and disease 13 37904697
2009 The PcG protein hPc2 interacts with the N-terminus of histone demethylase JARID1B and acts as a transcriptional co-repressor. BMB reports 12 19336002
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
2021 Role of novel cancer gene SLITRK3 to activate NTRK3 in squamous cell lung cancer. Molecular biomedicine 6 35006496
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