{"gene":"EPB41L1","run_date":"2026-04-28T17:46:03","timeline":{"discoveries":[{"year":2009,"finding":"4.1N is required for activity-dependent GluR1 (GluA1) AMPA receptor insertion into the plasma membrane. PKC phosphorylation of GluR1 at S816 and S818 enhances 4.1N binding to GluR1 and facilitates insertion. Palmitoylation of GluR1 C811 modulates PKC phosphorylation and GluR1 insertion. Disrupting 4.1N-dependent GluR1 insertion decreases surface GluR1 expression and impairs LTP expression.","method":"Live imaging of individual insertion events, co-immunoprecipitation, site-directed mutagenesis, dominant-negative constructs, LTP electrophysiology in rodents","journal":"Nature neuroscience","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods (live imaging, mutagenesis, co-IP, electrophysiology) in a single rigorous study; highly cited foundational paper","pmids":["19503082"],"is_preprint":false},{"year":2000,"finding":"4.1N binds the nuclear GTPase PIKE (PI3-Kinase Enhancer). NGF stimulates 4.1N translocation to the nucleus where it interacts with PIKE and inhibits PIKE-mediated activation of nuclear PI3K. Overexpression of 4.1N abolishes PIKE effects on PI3K lipid kinase activity.","method":"Yeast two-hybrid, co-immunoprecipitation, PI3K lipid kinase assay, overexpression/dominant-negative in cell lines","journal":"Cell","confidence":"High","confidence_rationale":"Tier 1-2 — biochemical kinase assay plus co-IP plus genetic overexpression; highly cited foundational paper","pmids":["11136977"],"is_preprint":false},{"year":2002,"finding":"4.1N interacts with D2 and D3 dopamine receptors via the N-terminal segment of the third intracellular loop of D2/D3 and the C-terminal domain of 4.1N. This interaction is required for cell-surface localization/stability of D2 and D3 receptors at the plasma membrane.","method":"Yeast two-hybrid, pulldown, co-immunoprecipitation, deletion mapping, immunofluorescence in HEK293 and Neuro2A cells with truncation fragment dominant-negative","journal":"Molecular pharmacology","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP, deletion mapping, and functional localization assay; highly cited","pmids":["12181426"],"is_preprint":false},{"year":2002,"finding":"4.1N binds the C-terminal cytoplasmic tail of IP3R1 and is required for translocation of IP3R1 to the basolateral membrane domain in polarized MDCK epithelial cells. The 4.1N-binding region of IP3R1 is necessary and sufficient for basolateral targeting, and a fragment of the IP3R1-binding region of 4.1N blocks basolateral co-localization.","method":"Yeast two-hybrid, co-immunoprecipitation in MDCK cells, dominant-negative fragment expression, immunofluorescence in confluent vs. subconfluent cells","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP, dominant-negative, localization with clear functional consequence; well-cited","pmids":["12444087"],"is_preprint":false},{"year":1999,"finding":"4.1N interacts with NuMA (nuclear mitotic apparatus protein) via its C-terminal domain. NGF induces 4.1N translocation to the nucleus and association with NuMA. Nuclear-targeted 4.1N arrests PC12 cells at G1 and causes aberrant nuclear morphology. Inhibition of 4.1N nuclear translocation prevents NGF-mediated arrest of cell division.","method":"Co-immunoprecipitation, deletion mapping, nuclear targeting constructs, cell-cycle analysis in PC12 cells, NGF treatment","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP plus functional cell-cycle phenotype rescue experiments","pmids":["10594058"],"is_preprint":false},{"year":2004,"finding":"4.1N links IP3R1 to actin filaments in neuronal dendrites, restricting IP3R1 lateral diffusion on the ER membrane. Overexpression of dominant-negative 4.1N or blockade of 4.1N binding to IP3R1 increased the IP3R1 diffusion constant. Actin depletion phenocopied loss of 4.1N. Adding a 4.1N-binding sequence to IP3R3 (which normally lacks it) conferred actin-dependent diffusion restriction.","method":"FRAP (fluorescence recovery after photobleaching) in live rat hippocampal neurons, dominant-negative 4.1N overexpression, actin depolymerization, chimeric IP3R3 with 4.1N-binding sequence","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — quantitative live-cell FRAP with multiple genetic controls and domain-swap experiments","pmids":["15364918"],"is_preprint":false},{"year":2003,"finding":"4.1N associates with IP3R1 in neurons through the CTD (C-terminal domain) of 4.1N and a 50-amino-acid segment in the IP3R1 C-terminal tail (CTM1). 4.1N and IP3R1 are co-immunoprecipitated from rat brain synaptosomes. In vitro biochemical experiments demonstrated a quaternary IP3R1-4.1N-CASK-syndecan-2 complex.","method":"Yeast two-hybrid (rat brain cDNA library), in vitro binding assay, co-immunoprecipitation from brain synaptosomes, domain mapping","journal":"Molecular and cellular neurosciences","confidence":"High","confidence_rationale":"Tier 2 — in vitro binding plus native brain co-IP plus quaternary complex reconstitution","pmids":["12676536"],"is_preprint":false},{"year":2013,"finding":"4.1N interacts with GluK1 and GluK2 kainate receptor subunits through a membrane-proximal C-terminal domain. This interaction regulates forward trafficking, plasma membrane distribution, and endocytosis of GluK2a receptors. Palmitoylation of GluK2a promotes 4.1N association and surface expression, while PKC activation decreases 4.1N-GluK2/3 interaction in acute brain slices.","method":"Co-immunoprecipitation, surface biotinylation, domain mapping, palmitoylation-deficient mutants, PKC inhibitor/activator treatment in brain slices","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods including native tissue co-IP, mutagenesis, and pharmacological manipulation","pmids":["23400781"],"is_preprint":false},{"year":2016,"finding":"4.1N interacts with phosphatase PP1 via its FERM domain. Ectopic 4.1N expression inactivates the JNK-c-Jun signaling pathway by enhancing PP1 activity and promoting PP1–p-JNK interaction. This suppresses downstream targets ezrin, MMP9, p53, p21, and p19 in NSCLC cells.","method":"Co-immunoprecipitation, PP1 activity assay, ectopic expression and knockdown, mouse xenograft model","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2-3 — co-IP plus enzymatic activity assay plus in vivo xenograft, single lab","pmids":["26575790"],"is_preprint":false},{"year":2005,"finding":"NECL1 (nectin-like molecule 1) associates with 4.1N in vitro and recruits 4.1N from the cytoplasm to the plasma membrane through its C-terminus, suggesting 4.1N is regulated in its subcellular localization by transmembrane binding partners.","method":"In vitro binding assay, co-immunoprecipitation, immunofluorescence, deletion mapping","journal":"Biochimica et biophysica acta","confidence":"Medium","confidence_rationale":"Tier 3 — single lab, co-IP plus localization assay","pmids":["15893517"],"is_preprint":false},{"year":2006,"finding":"Both the C-terminal 14 amino acids (CTT14aa) and the CTM1 segment of IP3R1 can bind 4.1N in peptide form, but CTT14aa is the primary binding site responsible for 4.1N-mediated regulation of IP3R1 diffusion in full-length tetrameric IP3R1.","method":"Co-immunoprecipitation with truncation fragments, FRAP in neuronal dendrites comparing IP3R1-ΔCT14aa vs. full length","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 — biochemical co-IP combined with functional FRAP assay, resolves prior conflicting data","pmids":["16487933"],"is_preprint":false},{"year":2011,"finding":"The IP3R1–4.1N interaction is required for Ca2+ wave formation (vs. homogeneous Ca2+ release) and neurite formation in NGF-differentiated PC12 cells. Knockdown of either IP3R1 or 4.1N or use of dominant-negative binding fragments attenuates neurite development and shifts Ca2+ signals from waves to uniform patterns.","method":"RNAi knockdown, dominant-negative overexpression, confocal Ca2+ imaging, neurite morphometry in PC12 cells","journal":"Neuro-Signals","confidence":"Medium","confidence_rationale":"Tier 2 — RNAi plus dominant-negative plus live Ca2+ imaging with defined cellular phenotype; single lab","pmids":["21389686"],"is_preprint":false},{"year":2013,"finding":"4.1N interacts with the α7 acetylcholine receptor (α7 AChR) and is required for surface localization of α7 AChR. The lipid DCP-LA increases the α7 AChR–4.1N association in a PKC-dependent manner (without phosphorylating 4.1N itself). Knockdown of 4.1N suppresses and DCP-LA-stimulated surface localization of α7 AChR.","method":"Yeast two-hybrid, co-immunoprecipitation, membrane fractionation, knockdown, live-cell receptor surface imaging in PC12 cells and hippocampal slices","journal":"The Biochemical journal","confidence":"Medium","confidence_rationale":"Tier 2-3 — multiple complementary assays, single lab","pmids":["23256752"],"is_preprint":false},{"year":2018,"finding":"IP6K2 binds 4.1N with high affinity and specificity. Nuclear translocation of 4.1N is dependent on IP6K2. In cerebellar granule cells, IP6K2–4.1N interaction regulates Purkinje cell morphology and cerebellar synapses. Disruption of IP6K2–4.1N interactions impairs cell viability. IP6K2 knockout mice show impaired locomotor function.","method":"Co-immunoprecipitation/binding assay, IP6K2 knockout mice, immunohistochemistry, electrophysiology, behavioral locomotor testing","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 — binding assay plus KO mouse with defined neurological and cellular phenotypes; single lab","pmids":["30006360"],"is_preprint":false},{"year":2018,"finding":"4.1N localizes to the lateral membrane of human bronchial epithelial cells where it associates with E-cadherin, β-catenin, and βII spectrin. Depletion of 4.1N by RNAi reduces lateral membrane height; re-expression of 4.1N rescues this phenotype. The final elongation phase of lateral membrane biogenesis requires 4.1N.","method":"RNAi knockdown, rescue by re-expression of mouse 4.1N, co-immunoprecipitation, immunofluorescence, membrane height measurement in human bronchial epithelial cells","journal":"Biochimica et biophysica acta. Biomembranes","confidence":"Medium","confidence_rationale":"Tier 2 — RNAi + rescue experiment + co-IP with defined morphological phenotype","pmids":["29428502"],"is_preprint":false},{"year":2023,"finding":"During LTP, CaMKII phosphorylates 4.1N and enhances formation of a p-CaMKII–4.1N–GluA1 complex, facilitating GluA1 trafficking to postsynaptic densities. Disrupting 4.1N–GluA1 interaction with Tat-GluA1(MPR) or CaMKII inhibition (Myr-AIP) blocked TBS-LTP and postsynaptic GluA1 increase. The 4.1N–GluA1 interaction is required for LTP but not for basal synaptic transmission.","method":"Co-immunoprecipitation, immunoblotting for phosphorylation, interfering peptide (Tat-GluA1 MPR) and CaMKII inhibitor in acute rat hippocampal slices, electrophysiology","journal":"Neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 — co-IP plus pharmacological inhibition plus peptide disruption with electrophysiological readout; single lab","pmids":["37993087"],"is_preprint":false},{"year":2023,"finding":"4.1N regulates GluA1 intracellular transport (IT) and exocytosis. During basal transmission, 4.1N binding to GluA1 allows exocytosis while SAP97 is essential for GluA1 IT. During cLTP, 4.1N interaction with GluA1 allows both IT and exocytosis. Downregulation of 4.1N decreases GluA1 IT velocity and plasma membrane export.","method":"RNAi knockdown, live-cell imaging of GluA1 transport vesicles, surface biotinylation, cLTP induction in cultured neurons","journal":"eLife","confidence":"Medium","confidence_rationale":"Tier 2 — RNAi plus live trafficking imaging with cLTP manipulation; single lab","pmids":["37079350"],"is_preprint":false},{"year":2023,"finding":"4.1N is highly expressed in dentate gyrus (DG) granule neurons; reducing 4.1N expression in DG granule neurons decreases glutamatergic synapse number and function. The FERM domain of 4.1N, not its CTD, is essential for supporting synaptic AMPAR function in DG granule neurons. Reducing 4.1N in CA1 pyramidal neurons has no effect on basal glutamatergic transmission.","method":"Viral-mediated knockdown, domain-deletion constructs, whole-cell patch-clamp electrophysiology in rat hippocampal slices, cell-type-specific targeting","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 — domain-specific rescue experiments with electrophysiological phenotype; single lab","pmids":["37845032"],"is_preprint":false},{"year":2020,"finding":"4.1N directly binds and accelerates degradation of 14-3-3 in suspension epithelial ovarian cancer (EOC) cells, thereby inhibiting anoikis resistance and EMT. Loss of 4.1N increases entosis. In adherent cells, 4.1N loss induces EMT. These effects were confirmed in mouse xenograft peritoneal dissemination models.","method":"Co-immunoprecipitation, ectopic expression/knockdown, protein degradation assay, xenograft mouse model, in vitro anoikis/entosis assays","journal":"Protein & cell","confidence":"Medium","confidence_rationale":"Tier 2-3 — co-IP with functional follow-up in vitro and in vivo; single lab","pmids":["32448967"],"is_preprint":false},{"year":2020,"finding":"4.1N deficiency in mice (4.1N−/−) causes selective atrophy of reproductive organs (testis and ovary), absence of spermatogenesis and follicular development, decreased secretory granules in the pituitary, and loss of GnRH from hypothalamic axons (retained in cell bodies only), indicating 4.1N is required for hypothalamic–pituitary–gonadal axis function.","method":"4.1N knockout mouse model, histopathology, immunohistochemistry for GnRH, organ weight measurement","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 — knockout mouse with specific tissue and subcellular phenotypes; single lab","pmids":["33046791"],"is_preprint":false},{"year":2016,"finding":"4.1N directly interacts with flotillin-1 through its FERM and U2 domains and suppresses cell proliferation and migration in NSCLC cells through a flotillin-1/β-catenin/Wnt signaling pathway.","method":"Immunoprecipitation, co-immunoprecipitation, pulldown assay, siRNA knockdown and overexpression in paired 95C/95D NSCLC cell lines","journal":"Tumour biology","confidence":"Medium","confidence_rationale":"Tier 3 — co-IP plus domain mapping plus functional assay; single lab","pmids":["27448302"],"is_preprint":false},{"year":2025,"finding":"Disrupting the 4.1N binding site on GluA1 (via GluA1 C80 peptide) in hippocampal CA1 impairs LTP and short-term spatial memory in mice, confirming that the 4.1N–GluA1 interaction is functionally required for synaptic plasticity and spatial memory.","method":"Viral expression of GluA1 C80 interfering peptide in vivo, LTP electrophysiology, spatial memory behavioral testing (Y-maze/Morris water maze variants) in mice","journal":"Neuroscience bulletin","confidence":"Medium","confidence_rationale":"Tier 2 — in vivo peptide interference with electrophysiological and behavioral readouts; single lab","pmids":["41417164"],"is_preprint":false}],"current_model":"EPB41L1/4.1N is a neuron-enriched FERM-domain scaffolding protein that links transmembrane receptors (GluA1/GluA4 AMPA receptors, GluK1/K2 kainate receptors, D2/D3 dopamine receptors, α7 AChR, IP3R1) to the spectrin-actin cytoskeleton, regulating their surface trafficking, membrane stabilization, and lateral diffusion; its nuclear translocation downstream of NGF modulates PI3K activity via PIKE and antagonizes NuMA to mediate cell-cycle arrest, while in non-neuronal contexts it suppresses tumor progression by recruiting PP1 to inactivate JNK-c-Jun signaling and by promoting 14-3-3 degradation to inhibit EMT and anoikis resistance."},"narrative":{"teleology":[{"year":1999,"claim":"Establishing that 4.1N has a nuclear function: NGF-induced nuclear translocation of 4.1N and interaction with NuMA demonstrated that this cytoskeletal adaptor has a direct role in cell-cycle control, arresting cells at G1.","evidence":"Co-immunoprecipitation, nuclear-targeting constructs, cell-cycle analysis in PC12 cells treated with NGF","pmids":["10594058"],"confidence":"High","gaps":["Mechanism of 4.1N nuclear import signal recognition is not defined","Whether NuMA interaction is direct or through bridging partners in vivo is unclear"]},{"year":2000,"claim":"Revealing a second nuclear target: 4.1N inhibits PIKE-mediated activation of nuclear PI3K upon NGF stimulation, establishing 4.1N as a negative regulator of nuclear PI3K signaling distinct from its NuMA interaction.","evidence":"Yeast two-hybrid, co-immunoprecipitation, PI3K lipid kinase assay with overexpression in cell lines","pmids":["11136977"],"confidence":"High","gaps":["Whether PIKE inhibition and NuMA binding are coordinated or independent nuclear functions is unknown","Physiological significance of nuclear PI3K inhibition in neurons in vivo is untested"]},{"year":2002,"claim":"Demonstrating that 4.1N anchors diverse transmembrane receptors at the cell surface: direct binding to D2/D3 dopamine receptors and IP3R1 via the 4.1N C-terminal domain established a general paradigm for receptor membrane stabilization by this scaffold.","evidence":"Yeast two-hybrid, co-immunoprecipitation, dominant-negative fragment expression in HEK293/Neuro2A and MDCK cells","pmids":["12181426","12444087"],"confidence":"High","gaps":["Whether 4.1N binding selectivity among receptors is governed by competition or compartmentalization is unresolved","Structural basis of C-terminal domain recognition of different receptor tails is unknown"]},{"year":2004,"claim":"Defining the cytoskeletal anchoring mechanism: FRAP experiments showed 4.1N restricts IP3R1 lateral diffusion on the ER membrane in an actin-dependent manner, and domain-swap experiments with IP3R3 confirmed sufficiency of the 4.1N-binding sequence.","evidence":"FRAP in live hippocampal neurons, dominant-negative 4.1N, actin depolymerization, chimeric IP3R3","pmids":["15364918"],"confidence":"High","gaps":["Identity of the spectrin or actin isoform partner mediating ER-proximal anchoring is not determined","Whether diffusion restriction applies to other 4.1N-bound ER proteins is untested"]},{"year":2009,"claim":"Establishing 4.1N as essential for activity-dependent AMPA receptor insertion and LTP: PKC phosphorylation of GluA1 at S816/S818 enhances 4.1N binding and drives membrane insertion events critical for LTP expression.","evidence":"Live imaging of individual insertion events, site-directed mutagenesis, co-IP, LTP electrophysiology in rodent hippocampal neurons","pmids":["19503082"],"confidence":"High","gaps":["Whether 4.1N also participates in GluA1 recycling/endocytosis during LTD is unknown","The vesicular compartment from which 4.1N-dependent insertion occurs is not identified"]},{"year":2013,"claim":"Extending receptor anchoring to kainate receptors and nicotinic receptors: 4.1N regulates surface trafficking of GluK1/K2 and α7 AChR, with palmitoylation and PKC activity modulating these interactions, broadening 4.1N's role as a general receptor trafficking scaffold.","evidence":"Co-immunoprecipitation, surface biotinylation, palmitoylation-deficient mutants in brain slices (kainate); yeast two-hybrid, knockdown, membrane fractionation in PC12/hippocampal slices (α7 AChR)","pmids":["23400781","23256752"],"confidence":"Medium","gaps":["Competition or cooperation among multiple receptor cargoes for 4.1N binding is not addressed","In vivo behavioral consequence of 4.1N loss on kainate or α7 AChR signaling is untested"]},{"year":2016,"claim":"Revealing a tumor-suppressive mechanism: 4.1N recruits PP1 via its FERM domain to inactivate JNK–c-Jun signaling and interacts with flotillin-1 to suppress Wnt/β-catenin signaling in NSCLC cells, extending 4.1N function beyond neurons.","evidence":"Co-immunoprecipitation, PP1 activity assay, ectopic expression/knockdown, xenograft models in NSCLC cell lines","pmids":["26575790","27448302"],"confidence":"Medium","gaps":["Whether PP1 recruitment is direct or mediated by a PP1-targeting subunit is unresolved","Relevance of JNK and Wnt pathway suppression to normal non-neuronal 4.1N physiology is unclear"]},{"year":2018,"claim":"Identifying IP6K2 as a nuclear transport regulator and demonstrating 4.1N's role in cerebellar and reproductive physiology: IP6K2 binds 4.1N to enable nuclear translocation and regulate Purkinje cell morphology, while 4.1N knockout mice show hypothalamic–pituitary–gonadal axis failure with absent GnRH axonal transport.","evidence":"IP6K2 knockout mice with locomotor and cerebellar phenotypes; 4.1N knockout mice with reproductive organ atrophy and GnRH mislocalization; immunohistochemistry, electrophysiology","pmids":["30006360","33046791"],"confidence":"Medium","gaps":["Molecular cargo 4.1N transports along GnRH axons is undefined","Whether IP6K2-dependent nuclear translocation is the sole mechanism for 4.1N nuclear entry is unknown","Contribution of 4.1N loss in pituitary versus hypothalamus to reproductive failure is not dissected"]},{"year":2020,"claim":"Demonstrating 4.1N suppresses anoikis resistance and EMT in ovarian cancer by promoting 14-3-3 degradation, revealing a non-neuronal scaffolding mechanism with direct relevance to metastasis.","evidence":"Co-immunoprecipitation, protein degradation assay, knockdown/overexpression, xenograft peritoneal dissemination model in epithelial ovarian cancer cells","pmids":["32448967"],"confidence":"Medium","gaps":["E3 ligase or degradation pathway mediating 4.1N-induced 14-3-3 turnover is not identified","Whether this mechanism operates in normal epithelia is unknown"]},{"year":2023,"claim":"Refining the synaptic plasticity mechanism: CaMKII phosphorylation of 4.1N drives formation of a pCaMKII–4.1N–GluA1 complex essential for LTP; 4.1N FERM domain (not CTD) supports synaptic function specifically in dentate gyrus granule neurons, revealing cell-type specificity.","evidence":"Co-IP for phospho-complexes, interfering peptides, CaMKII inhibitors, domain-deletion rescue, electrophysiology in hippocampal slices, cell-type-specific viral knockdown","pmids":["37993087","37845032","37079350"],"confidence":"Medium","gaps":["CaMKII phosphorylation site(s) on 4.1N are not mapped","Why CA1 neurons are resistant to 4.1N loss while DG neurons are not is mechanistically unexplained","Whether FERM-domain-dependent synaptic role involves PP1 or other FERM interactors is untested"]},{"year":2025,"claim":"Providing in vivo behavioral validation: disrupting the 4.1N–GluA1 interaction specifically in hippocampal CA1 impairs LTP and short-term spatial memory, confirming this interaction is required for cognitive function.","evidence":"Viral expression of GluA1 C80 interfering peptide in mouse CA1, LTP electrophysiology, Y-maze/Morris water maze behavioral testing","pmids":["41417164"],"confidence":"Medium","gaps":["Long-term memory and other hippocampus-dependent tasks beyond spatial memory are not assessed","Whether compensatory mechanisms involving other 4.1 family members mitigate the phenotype is unexplored"]},{"year":null,"claim":"Key unresolved questions include the structural basis of 4.1N's multi-receptor recognition, the identity of CaMKII phosphorylation sites on 4.1N, the mechanism governing cell-type-specific requirements (DG vs. CA1), and the molecular basis of 4.1N's roles in GnRH axonal transport and reproductive axis function.","evidence":"","pmids":[],"confidence":"Low","gaps":["No crystal or cryo-EM structure of 4.1N in complex with any receptor tail","CaMKII phosphorylation sites on 4.1N not mapped","Molecular mechanism of GnRH transport dependence on 4.1N not characterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2,3,7,12,14]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[5,6,14]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,8,18]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,2,7,9,12,14]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[1,4,13]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[5,6,14]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[9,16]}],"pathway":[{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[0,7,15,17,21]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,8,20]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[4]},{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[2,3,12,16]}],"complexes":["IP3R1-4.1N-CASK-syndecan-2 complex","CaMKII-4.1N-GluA1 complex"],"partners":["GRIA1","GRIK2","DRD2","ITPR1","NUMA1","AGAP2","IP6K2","PPP1CA"],"other_free_text":[]},"mechanistic_narrative":"EPB41L1 (protein 4.1N) is a neuron-enriched FERM-domain scaffolding protein that bridges transmembrane receptors to the spectrin–actin cytoskeleton, controlling their surface trafficking, membrane stabilization, and lateral diffusion. In the hippocampus, 4.1N is phosphorylated by CaMKII during LTP to promote assembly of a CaMKII–4.1N–GluA1 complex that drives AMPA receptor insertion into postsynaptic densities, a process essential for synaptic plasticity and spatial memory [PMID:19503082, PMID:37993087, PMID:41417164]. Beyond GluA1, 4.1N anchors kainate receptors (GluK1/K2), D2/D3 dopamine receptors, α7 AChR, and IP3R1 at the plasma membrane or ER through its C-terminal domain, restricting IP3R1 lateral diffusion in an actin-dependent manner and shaping dendritic calcium wave propagation [PMID:23400781, PMID:12181426, PMID:15364918, PMID:21389686]. NGF-stimulated nuclear translocation of 4.1N, mediated by IP6K2, enables interaction with NuMA to enforce G1 arrest and with PIKE to inhibit nuclear PI3K activity, while in epithelial and cancer cells 4.1N recruits PP1 to inactivate JNK–c-Jun signaling and promotes 14-3-3 degradation to suppress EMT and anoikis resistance [PMID:10594058, PMID:11136977, PMID:30006360, PMID:26575790, PMID:32448967]."},"prefetch_data":{"uniprot":{"accession":"Q9H4G0","full_name":"Band 4.1-like protein 1","aliases":["Erythrocyte membrane protein band 4.1-like 1","Neuronal protein 4.1","4.1N"],"length_aa":881,"mass_kda":98.5,"function":"May function to confer stability and plasticity to neuronal membrane via multiple interactions, including the spectrin-actin-based cytoskeleton, integral membrane channels and membrane-associated guanylate kinases","subcellular_location":"Cytoplasm, cytoskeleton","url":"https://www.uniprot.org/uniprotkb/Q9H4G0/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/EPB41L1","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CLNS1A","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/EPB41L1","total_profiled":1310},"omim":[{"mim_id":"614257","title":"CHROMOSOME 20q11-q12 DELETION SYNDROME","url":"https://www.omim.org/entry/614257"},{"mim_id":"612406","title":"DYSTONIA 17, TORSION, AUTOSOMAL RECESSIVE; DYT17","url":"https://www.omim.org/entry/612406"},{"mim_id":"602879","title":"ERYTHROCYTE MEMBRANE PROTEIN BAND 4.1-LIKE 1; EPB41L1","url":"https://www.omim.org/entry/602879"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Plasma membrane","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/EPB41L1"},"hgnc":{"alias_symbol":["KIAA0338","4.1N"],"prev_symbol":[]},"alphafold":{"accession":"Q9H4G0","domains":[{"cath_id":"3.10.20.90","chopping":"97-174","consensus_level":"high","plddt":95.4859,"start":97,"end":174},{"cath_id":"1.20.80.10","chopping":"181-279","consensus_level":"high","plddt":95.5609,"start":181,"end":279},{"cath_id":"2.30.29.30","chopping":"287-382_391-409","consensus_level":"high","plddt":90.8379,"start":287,"end":409}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H4G0","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H4G0-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H4G0-F1-predicted_aligned_error_v6.png","plddt_mean":61.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=EPB41L1","jax_strain_url":"https://www.jax.org/strain/search?query=EPB41L1"},"sequence":{"accession":"Q9H4G0","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H4G0.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H4G0/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H4G0"}},"corpus_meta":[{"pmid":"19503082","id":"PMC_19503082","title":"Regulation of AMPA receptor extrasynaptic insertion by 4.1N, phosphorylation and palmitoylation.","date":"2009","source":"Nature neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/19503082","citation_count":288,"is_preprint":false},{"pmid":"11136977","id":"PMC_11136977","title":"Pike. A nuclear gtpase that enhances PI3kinase activity and is regulated by protein 4.1N.","date":"2000","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/11136977","citation_count":147,"is_preprint":false},{"pmid":"12181426","id":"PMC_12181426","title":"D2 and D3 dopamine receptor cell surface localization mediated by interaction with protein 4.1N.","date":"2002","source":"Molecular pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/12181426","citation_count":109,"is_preprint":false},{"pmid":"15364918","id":"PMC_15364918","title":"Lateral diffusion of inositol 1,4,5-trisphosphate receptor type 1 is regulated by actin filaments and 4.1N in neuronal dendrites.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15364918","citation_count":76,"is_preprint":false},{"pmid":"12444087","id":"PMC_12444087","title":"Protein 4.1N is required for translocation of inositol 1,4,5-trisphosphate receptor type 1 to the basolateral membrane domain in polarized Madin-Darby canine kidney cells.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12444087","citation_count":72,"is_preprint":false},{"pmid":"10594058","id":"PMC_10594058","title":"Protein 4.1N binding to nuclear mitotic apparatus protein in PC12 cells mediates the antiproliferative actions of nerve growth factor.","date":"1999","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/10594058","citation_count":60,"is_preprint":false},{"pmid":"17335044","id":"PMC_17335044","title":"Differential neuronal and glial expression of GluR1 AMPA receptor subunit and the scaffolding proteins SAP97 and 4.1N during rat cerebellar development.","date":"2007","source":"The Journal of comparative neurology","url":"https://pubmed.ncbi.nlm.nih.gov/17335044","citation_count":52,"is_preprint":false},{"pmid":"12676536","id":"PMC_12676536","title":"Association of the type 1 inositol (1,4,5)-trisphosphate receptor with 4.1N protein in neurons.","date":"2003","source":"Molecular and cellular neurosciences","url":"https://pubmed.ncbi.nlm.nih.gov/12676536","citation_count":49,"is_preprint":false},{"pmid":"15893517","id":"PMC_15893517","title":"Nectin-like molecule 1 is a protein 4.1N associated protein and recruits protein 4.1N from cytoplasm to the plasma membrane.","date":"2005","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/15893517","citation_count":34,"is_preprint":false},{"pmid":"23400781","id":"PMC_23400781","title":"Kainate receptor post-translational modifications differentially regulate association with 4.1N to control activity-dependent receptor endocytosis.","date":"2013","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23400781","citation_count":32,"is_preprint":false},{"pmid":"26575790","id":"PMC_26575790","title":"Protein 4.1N acts as a potential tumor suppressor linking PP1 to JNK-c-Jun pathway regulation in NSCLC.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/26575790","citation_count":23,"is_preprint":false},{"pmid":"19225127","id":"PMC_19225127","title":"The function of glutamatergic synapses is not perturbed by severe knockdown of 4.1N and 4.1G expression.","date":"2009","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/19225127","citation_count":22,"is_preprint":false},{"pmid":"32448967","id":"PMC_32448967","title":"Loss of 4.1N in epithelial ovarian cancer results in EMT and matrix-detached cell death resistance.","date":"2020","source":"Protein & cell","url":"https://pubmed.ncbi.nlm.nih.gov/32448967","citation_count":21,"is_preprint":false},{"pmid":"16487933","id":"PMC_16487933","title":"4.1N binding regions of inositol 1,4,5-trisphosphate receptor type 1.","date":"2006","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/16487933","citation_count":20,"is_preprint":false},{"pmid":"23994105","id":"PMC_23994105","title":"Defective expression of Protein 4.1N is correlated to tumor progression, aggressive behaviors and chemotherapy resistance in epithelial ovarian cancer.","date":"2013","source":"Gynecologic oncology","url":"https://pubmed.ncbi.nlm.nih.gov/23994105","citation_count":17,"is_preprint":false},{"pmid":"37079350","id":"PMC_37079350","title":"Regulation of different phases of AMPA receptor intracellular transport by 4.1N and SAP97.","date":"2023","source":"eLife","url":"https://pubmed.ncbi.nlm.nih.gov/37079350","citation_count":16,"is_preprint":false},{"pmid":"30006360","id":"PMC_30006360","title":"Inositol Hexakisphosphate Kinase-2 in Cerebellar Granule Cells Regulates Purkinje Cells and Motor Coordination via Protein 4.1N.","date":"2018","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/30006360","citation_count":16,"is_preprint":false},{"pmid":"23170136","id":"PMC_23170136","title":"The membrane-cytoskeletal protein 4.1N is involved in the process of cell adhesion, migration and invasion of breast cancer cells.","date":"2012","source":"Experimental and therapeutic medicine","url":"https://pubmed.ncbi.nlm.nih.gov/23170136","citation_count":15,"is_preprint":false},{"pmid":"27448302","id":"PMC_27448302","title":"4.1N is involved in a flotillin-1/β-catenin/Wnt pathway and suppresses cell proliferation and migration in non-small cell lung cancer cell lines.","date":"2016","source":"Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/27448302","citation_count":14,"is_preprint":false},{"pmid":"21389686","id":"PMC_21389686","title":"The type I inositol 1,4,5-trisphosphate receptor interacts with protein 4.1N to mediate neurite formation through intracellular Ca waves.","date":"2011","source":"Neuro-Signals","url":"https://pubmed.ncbi.nlm.nih.gov/21389686","citation_count":14,"is_preprint":false},{"pmid":"16122796","id":"PMC_16122796","title":"Protein 4.1N does not interact with the inositol 1,4,5-trisphosphate receptor in an epithelial cell line.","date":"2005","source":"Cell calcium","url":"https://pubmed.ncbi.nlm.nih.gov/16122796","citation_count":10,"is_preprint":false},{"pmid":"34589518","id":"PMC_34589518","title":"4.1N-Mediated Interactions and Functions in Nerve System and Cancer.","date":"2021","source":"Frontiers in molecular biosciences","url":"https://pubmed.ncbi.nlm.nih.gov/34589518","citation_count":8,"is_preprint":false},{"pmid":"35795202","id":"PMC_35795202","title":"Tumor Suppressor 4.1N/EPB41L1 is Epigenetic Silenced by Promoter Methylation and MiR-454-3p in NSCLC.","date":"2022","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/35795202","citation_count":8,"is_preprint":false},{"pmid":"31749885","id":"PMC_31749885","title":"Mechanism of microRNA-431-5p-EPB41L1 interaction in glioblastoma multiforme cells.","date":"2019","source":"Archives of medical science : AMS","url":"https://pubmed.ncbi.nlm.nih.gov/31749885","citation_count":7,"is_preprint":false},{"pmid":"23256752","id":"PMC_23256752","title":"The linoleic acid derivative DCP-LA increases membrane surface localization of the α7 ACh receptor in a protein 4.1N-dependent manner.","date":"2013","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/23256752","citation_count":7,"is_preprint":false},{"pmid":"26648170","id":"PMC_26648170","title":"4.1N suppresses hypoxia-induced epithelial-mesenchymal transition in epithelial ovarian cancer cells.","date":"2015","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/26648170","citation_count":6,"is_preprint":false},{"pmid":"29428502","id":"PMC_29428502","title":"Protein 4.1N is required for the formation of the lateral membrane domain in human bronchial epithelial cells.","date":"2018","source":"Biochimica et biophysica acta. Biomembranes","url":"https://pubmed.ncbi.nlm.nih.gov/29428502","citation_count":6,"is_preprint":false},{"pmid":"37993087","id":"PMC_37993087","title":"Phosphorylation of 4.1N by CaMKII Regulates the Trafficking of GluA1-containing AMPA Receptors During Long-term Potentiation in Acute Rat Hippocampal Brain Slices.","date":"2023","source":"Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/37993087","citation_count":4,"is_preprint":false},{"pmid":"33046791","id":"PMC_33046791","title":"Selective effects of protein 4.1N deficiency on neuroendocrine and reproductive systems.","date":"2020","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/33046791","citation_count":3,"is_preprint":false},{"pmid":"31692885","id":"PMC_31692885","title":"Correction: Protein 4.1N acts as a potential tumor suppressor linking PP1 to JNK-c-Jun pathway regulation in NSCLC.","date":"2019","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/31692885","citation_count":2,"is_preprint":false},{"pmid":"37845032","id":"PMC_37845032","title":"Protein 4.1N Plays a Cell Type-Specific Role in Hippocampal Glutamatergic Synapse Regulation.","date":"2023","source":"The Journal of neuroscience : the official journal of the Society for Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/37845032","citation_count":1,"is_preprint":false},{"pmid":"41417164","id":"PMC_41417164","title":"GluA1 C80 Peptide Impairs Short-Term Spatial Memory in Mice by Interfering with the 4.1N Binding Site.","date":"2025","source":"Neuroscience bulletin","url":"https://pubmed.ncbi.nlm.nih.gov/41417164","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":16803,"output_tokens":5524,"usd":0.066634},"stage2":{"model":"claude-opus-4-6","input_tokens":9115,"output_tokens":3637,"usd":0.20475},"total_usd":0.271384,"stage1_batch_id":"msgbatch_0118RScg3WGaGkaZRtWZbtce","stage2_batch_id":"msgbatch_01Cpfzvtbj42aqp5oYZ5Te2s","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2009,\n      \"finding\": \"4.1N is required for activity-dependent GluR1 (GluA1) AMPA receptor insertion into the plasma membrane. PKC phosphorylation of GluR1 at S816 and S818 enhances 4.1N binding to GluR1 and facilitates insertion. Palmitoylation of GluR1 C811 modulates PKC phosphorylation and GluR1 insertion. Disrupting 4.1N-dependent GluR1 insertion decreases surface GluR1 expression and impairs LTP expression.\",\n      \"method\": \"Live imaging of individual insertion events, co-immunoprecipitation, site-directed mutagenesis, dominant-negative constructs, LTP electrophysiology in rodents\",\n      \"journal\": \"Nature neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods (live imaging, mutagenesis, co-IP, electrophysiology) in a single rigorous study; highly cited foundational paper\",\n      \"pmids\": [\"19503082\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"4.1N binds the nuclear GTPase PIKE (PI3-Kinase Enhancer). NGF stimulates 4.1N translocation to the nucleus where it interacts with PIKE and inhibits PIKE-mediated activation of nuclear PI3K. Overexpression of 4.1N abolishes PIKE effects on PI3K lipid kinase activity.\",\n      \"method\": \"Yeast two-hybrid, co-immunoprecipitation, PI3K lipid kinase assay, overexpression/dominant-negative in cell lines\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — biochemical kinase assay plus co-IP plus genetic overexpression; highly cited foundational paper\",\n      \"pmids\": [\"11136977\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"4.1N interacts with D2 and D3 dopamine receptors via the N-terminal segment of the third intracellular loop of D2/D3 and the C-terminal domain of 4.1N. This interaction is required for cell-surface localization/stability of D2 and D3 receptors at the plasma membrane.\",\n      \"method\": \"Yeast two-hybrid, pulldown, co-immunoprecipitation, deletion mapping, immunofluorescence in HEK293 and Neuro2A cells with truncation fragment dominant-negative\",\n      \"journal\": \"Molecular pharmacology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP, deletion mapping, and functional localization assay; highly cited\",\n      \"pmids\": [\"12181426\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"4.1N binds the C-terminal cytoplasmic tail of IP3R1 and is required for translocation of IP3R1 to the basolateral membrane domain in polarized MDCK epithelial cells. The 4.1N-binding region of IP3R1 is necessary and sufficient for basolateral targeting, and a fragment of the IP3R1-binding region of 4.1N blocks basolateral co-localization.\",\n      \"method\": \"Yeast two-hybrid, co-immunoprecipitation in MDCK cells, dominant-negative fragment expression, immunofluorescence in confluent vs. subconfluent cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP, dominant-negative, localization with clear functional consequence; well-cited\",\n      \"pmids\": [\"12444087\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"4.1N interacts with NuMA (nuclear mitotic apparatus protein) via its C-terminal domain. NGF induces 4.1N translocation to the nucleus and association with NuMA. Nuclear-targeted 4.1N arrests PC12 cells at G1 and causes aberrant nuclear morphology. Inhibition of 4.1N nuclear translocation prevents NGF-mediated arrest of cell division.\",\n      \"method\": \"Co-immunoprecipitation, deletion mapping, nuclear targeting constructs, cell-cycle analysis in PC12 cells, NGF treatment\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP plus functional cell-cycle phenotype rescue experiments\",\n      \"pmids\": [\"10594058\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"4.1N links IP3R1 to actin filaments in neuronal dendrites, restricting IP3R1 lateral diffusion on the ER membrane. Overexpression of dominant-negative 4.1N or blockade of 4.1N binding to IP3R1 increased the IP3R1 diffusion constant. Actin depletion phenocopied loss of 4.1N. Adding a 4.1N-binding sequence to IP3R3 (which normally lacks it) conferred actin-dependent diffusion restriction.\",\n      \"method\": \"FRAP (fluorescence recovery after photobleaching) in live rat hippocampal neurons, dominant-negative 4.1N overexpression, actin depolymerization, chimeric IP3R3 with 4.1N-binding sequence\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — quantitative live-cell FRAP with multiple genetic controls and domain-swap experiments\",\n      \"pmids\": [\"15364918\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"4.1N associates with IP3R1 in neurons through the CTD (C-terminal domain) of 4.1N and a 50-amino-acid segment in the IP3R1 C-terminal tail (CTM1). 4.1N and IP3R1 are co-immunoprecipitated from rat brain synaptosomes. In vitro biochemical experiments demonstrated a quaternary IP3R1-4.1N-CASK-syndecan-2 complex.\",\n      \"method\": \"Yeast two-hybrid (rat brain cDNA library), in vitro binding assay, co-immunoprecipitation from brain synaptosomes, domain mapping\",\n      \"journal\": \"Molecular and cellular neurosciences\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — in vitro binding plus native brain co-IP plus quaternary complex reconstitution\",\n      \"pmids\": [\"12676536\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"4.1N interacts with GluK1 and GluK2 kainate receptor subunits through a membrane-proximal C-terminal domain. This interaction regulates forward trafficking, plasma membrane distribution, and endocytosis of GluK2a receptors. Palmitoylation of GluK2a promotes 4.1N association and surface expression, while PKC activation decreases 4.1N-GluK2/3 interaction in acute brain slices.\",\n      \"method\": \"Co-immunoprecipitation, surface biotinylation, domain mapping, palmitoylation-deficient mutants, PKC inhibitor/activator treatment in brain slices\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including native tissue co-IP, mutagenesis, and pharmacological manipulation\",\n      \"pmids\": [\"23400781\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"4.1N interacts with phosphatase PP1 via its FERM domain. Ectopic 4.1N expression inactivates the JNK-c-Jun signaling pathway by enhancing PP1 activity and promoting PP1–p-JNK interaction. This suppresses downstream targets ezrin, MMP9, p53, p21, and p19 in NSCLC cells.\",\n      \"method\": \"Co-immunoprecipitation, PP1 activity assay, ectopic expression and knockdown, mouse xenograft model\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — co-IP plus enzymatic activity assay plus in vivo xenograft, single lab\",\n      \"pmids\": [\"26575790\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"NECL1 (nectin-like molecule 1) associates with 4.1N in vitro and recruits 4.1N from the cytoplasm to the plasma membrane through its C-terminus, suggesting 4.1N is regulated in its subcellular localization by transmembrane binding partners.\",\n      \"method\": \"In vitro binding assay, co-immunoprecipitation, immunofluorescence, deletion mapping\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab, co-IP plus localization assay\",\n      \"pmids\": [\"15893517\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Both the C-terminal 14 amino acids (CTT14aa) and the CTM1 segment of IP3R1 can bind 4.1N in peptide form, but CTT14aa is the primary binding site responsible for 4.1N-mediated regulation of IP3R1 diffusion in full-length tetrameric IP3R1.\",\n      \"method\": \"Co-immunoprecipitation with truncation fragments, FRAP in neuronal dendrites comparing IP3R1-ΔCT14aa vs. full length\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — biochemical co-IP combined with functional FRAP assay, resolves prior conflicting data\",\n      \"pmids\": [\"16487933\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"The IP3R1–4.1N interaction is required for Ca2+ wave formation (vs. homogeneous Ca2+ release) and neurite formation in NGF-differentiated PC12 cells. Knockdown of either IP3R1 or 4.1N or use of dominant-negative binding fragments attenuates neurite development and shifts Ca2+ signals from waves to uniform patterns.\",\n      \"method\": \"RNAi knockdown, dominant-negative overexpression, confocal Ca2+ imaging, neurite morphometry in PC12 cells\",\n      \"journal\": \"Neuro-Signals\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — RNAi plus dominant-negative plus live Ca2+ imaging with defined cellular phenotype; single lab\",\n      \"pmids\": [\"21389686\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"4.1N interacts with the α7 acetylcholine receptor (α7 AChR) and is required for surface localization of α7 AChR. The lipid DCP-LA increases the α7 AChR–4.1N association in a PKC-dependent manner (without phosphorylating 4.1N itself). Knockdown of 4.1N suppresses and DCP-LA-stimulated surface localization of α7 AChR.\",\n      \"method\": \"Yeast two-hybrid, co-immunoprecipitation, membrane fractionation, knockdown, live-cell receptor surface imaging in PC12 cells and hippocampal slices\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — multiple complementary assays, single lab\",\n      \"pmids\": [\"23256752\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"IP6K2 binds 4.1N with high affinity and specificity. Nuclear translocation of 4.1N is dependent on IP6K2. In cerebellar granule cells, IP6K2–4.1N interaction regulates Purkinje cell morphology and cerebellar synapses. Disruption of IP6K2–4.1N interactions impairs cell viability. IP6K2 knockout mice show impaired locomotor function.\",\n      \"method\": \"Co-immunoprecipitation/binding assay, IP6K2 knockout mice, immunohistochemistry, electrophysiology, behavioral locomotor testing\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — binding assay plus KO mouse with defined neurological and cellular phenotypes; single lab\",\n      \"pmids\": [\"30006360\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"4.1N localizes to the lateral membrane of human bronchial epithelial cells where it associates with E-cadherin, β-catenin, and βII spectrin. Depletion of 4.1N by RNAi reduces lateral membrane height; re-expression of 4.1N rescues this phenotype. The final elongation phase of lateral membrane biogenesis requires 4.1N.\",\n      \"method\": \"RNAi knockdown, rescue by re-expression of mouse 4.1N, co-immunoprecipitation, immunofluorescence, membrane height measurement in human bronchial epithelial cells\",\n      \"journal\": \"Biochimica et biophysica acta. Biomembranes\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — RNAi + rescue experiment + co-IP with defined morphological phenotype\",\n      \"pmids\": [\"29428502\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"During LTP, CaMKII phosphorylates 4.1N and enhances formation of a p-CaMKII–4.1N–GluA1 complex, facilitating GluA1 trafficking to postsynaptic densities. Disrupting 4.1N–GluA1 interaction with Tat-GluA1(MPR) or CaMKII inhibition (Myr-AIP) blocked TBS-LTP and postsynaptic GluA1 increase. The 4.1N–GluA1 interaction is required for LTP but not for basal synaptic transmission.\",\n      \"method\": \"Co-immunoprecipitation, immunoblotting for phosphorylation, interfering peptide (Tat-GluA1 MPR) and CaMKII inhibitor in acute rat hippocampal slices, electrophysiology\",\n      \"journal\": \"Neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — co-IP plus pharmacological inhibition plus peptide disruption with electrophysiological readout; single lab\",\n      \"pmids\": [\"37993087\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"4.1N regulates GluA1 intracellular transport (IT) and exocytosis. During basal transmission, 4.1N binding to GluA1 allows exocytosis while SAP97 is essential for GluA1 IT. During cLTP, 4.1N interaction with GluA1 allows both IT and exocytosis. Downregulation of 4.1N decreases GluA1 IT velocity and plasma membrane export.\",\n      \"method\": \"RNAi knockdown, live-cell imaging of GluA1 transport vesicles, surface biotinylation, cLTP induction in cultured neurons\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — RNAi plus live trafficking imaging with cLTP manipulation; single lab\",\n      \"pmids\": [\"37079350\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"4.1N is highly expressed in dentate gyrus (DG) granule neurons; reducing 4.1N expression in DG granule neurons decreases glutamatergic synapse number and function. The FERM domain of 4.1N, not its CTD, is essential for supporting synaptic AMPAR function in DG granule neurons. Reducing 4.1N in CA1 pyramidal neurons has no effect on basal glutamatergic transmission.\",\n      \"method\": \"Viral-mediated knockdown, domain-deletion constructs, whole-cell patch-clamp electrophysiology in rat hippocampal slices, cell-type-specific targeting\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — domain-specific rescue experiments with electrophysiological phenotype; single lab\",\n      \"pmids\": [\"37845032\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"4.1N directly binds and accelerates degradation of 14-3-3 in suspension epithelial ovarian cancer (EOC) cells, thereby inhibiting anoikis resistance and EMT. Loss of 4.1N increases entosis. In adherent cells, 4.1N loss induces EMT. These effects were confirmed in mouse xenograft peritoneal dissemination models.\",\n      \"method\": \"Co-immunoprecipitation, ectopic expression/knockdown, protein degradation assay, xenograft mouse model, in vitro anoikis/entosis assays\",\n      \"journal\": \"Protein & cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — co-IP with functional follow-up in vitro and in vivo; single lab\",\n      \"pmids\": [\"32448967\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"4.1N deficiency in mice (4.1N−/−) causes selective atrophy of reproductive organs (testis and ovary), absence of spermatogenesis and follicular development, decreased secretory granules in the pituitary, and loss of GnRH from hypothalamic axons (retained in cell bodies only), indicating 4.1N is required for hypothalamic–pituitary–gonadal axis function.\",\n      \"method\": \"4.1N knockout mouse model, histopathology, immunohistochemistry for GnRH, organ weight measurement\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — knockout mouse with specific tissue and subcellular phenotypes; single lab\",\n      \"pmids\": [\"33046791\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"4.1N directly interacts with flotillin-1 through its FERM and U2 domains and suppresses cell proliferation and migration in NSCLC cells through a flotillin-1/β-catenin/Wnt signaling pathway.\",\n      \"method\": \"Immunoprecipitation, co-immunoprecipitation, pulldown assay, siRNA knockdown and overexpression in paired 95C/95D NSCLC cell lines\",\n      \"journal\": \"Tumour biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — co-IP plus domain mapping plus functional assay; single lab\",\n      \"pmids\": [\"27448302\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Disrupting the 4.1N binding site on GluA1 (via GluA1 C80 peptide) in hippocampal CA1 impairs LTP and short-term spatial memory in mice, confirming that the 4.1N–GluA1 interaction is functionally required for synaptic plasticity and spatial memory.\",\n      \"method\": \"Viral expression of GluA1 C80 interfering peptide in vivo, LTP electrophysiology, spatial memory behavioral testing (Y-maze/Morris water maze variants) in mice\",\n      \"journal\": \"Neuroscience bulletin\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vivo peptide interference with electrophysiological and behavioral readouts; single lab\",\n      \"pmids\": [\"41417164\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"EPB41L1/4.1N is a neuron-enriched FERM-domain scaffolding protein that links transmembrane receptors (GluA1/GluA4 AMPA receptors, GluK1/K2 kainate receptors, D2/D3 dopamine receptors, α7 AChR, IP3R1) to the spectrin-actin cytoskeleton, regulating their surface trafficking, membrane stabilization, and lateral diffusion; its nuclear translocation downstream of NGF modulates PI3K activity via PIKE and antagonizes NuMA to mediate cell-cycle arrest, while in non-neuronal contexts it suppresses tumor progression by recruiting PP1 to inactivate JNK-c-Jun signaling and by promoting 14-3-3 degradation to inhibit EMT and anoikis resistance.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"EPB41L1 (protein 4.1N) is a neuron-enriched FERM-domain scaffolding protein that bridges transmembrane receptors to the spectrin–actin cytoskeleton, controlling their surface trafficking, membrane stabilization, and lateral diffusion. In the hippocampus, 4.1N is phosphorylated by CaMKII during LTP to promote assembly of a CaMKII–4.1N–GluA1 complex that drives AMPA receptor insertion into postsynaptic densities, a process essential for synaptic plasticity and spatial memory [PMID:19503082, PMID:37993087, PMID:41417164]. Beyond GluA1, 4.1N anchors kainate receptors (GluK1/K2), D2/D3 dopamine receptors, α7 AChR, and IP3R1 at the plasma membrane or ER through its C-terminal domain, restricting IP3R1 lateral diffusion in an actin-dependent manner and shaping dendritic calcium wave propagation [PMID:23400781, PMID:12181426, PMID:15364918, PMID:21389686]. NGF-stimulated nuclear translocation of 4.1N, mediated by IP6K2, enables interaction with NuMA to enforce G1 arrest and with PIKE to inhibit nuclear PI3K activity, while in epithelial and cancer cells 4.1N recruits PP1 to inactivate JNK–c-Jun signaling and promotes 14-3-3 degradation to suppress EMT and anoikis resistance [PMID:10594058, PMID:11136977, PMID:30006360, PMID:26575790, PMID:32448967].\",\n  \"teleology\": [\n    {\n      \"year\": 1999,\n      \"claim\": \"Establishing that 4.1N has a nuclear function: NGF-induced nuclear translocation of 4.1N and interaction with NuMA demonstrated that this cytoskeletal adaptor has a direct role in cell-cycle control, arresting cells at G1.\",\n      \"evidence\": \"Co-immunoprecipitation, nuclear-targeting constructs, cell-cycle analysis in PC12 cells treated with NGF\",\n      \"pmids\": [\"10594058\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Mechanism of 4.1N nuclear import signal recognition is not defined\",\n        \"Whether NuMA interaction is direct or through bridging partners in vivo is unclear\"\n      ]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Revealing a second nuclear target: 4.1N inhibits PIKE-mediated activation of nuclear PI3K upon NGF stimulation, establishing 4.1N as a negative regulator of nuclear PI3K signaling distinct from its NuMA interaction.\",\n      \"evidence\": \"Yeast two-hybrid, co-immunoprecipitation, PI3K lipid kinase assay with overexpression in cell lines\",\n      \"pmids\": [\"11136977\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether PIKE inhibition and NuMA binding are coordinated or independent nuclear functions is unknown\",\n        \"Physiological significance of nuclear PI3K inhibition in neurons in vivo is untested\"\n      ]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Demonstrating that 4.1N anchors diverse transmembrane receptors at the cell surface: direct binding to D2/D3 dopamine receptors and IP3R1 via the 4.1N C-terminal domain established a general paradigm for receptor membrane stabilization by this scaffold.\",\n      \"evidence\": \"Yeast two-hybrid, co-immunoprecipitation, dominant-negative fragment expression in HEK293/Neuro2A and MDCK cells\",\n      \"pmids\": [\"12181426\", \"12444087\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether 4.1N binding selectivity among receptors is governed by competition or compartmentalization is unresolved\",\n        \"Structural basis of C-terminal domain recognition of different receptor tails is unknown\"\n      ]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Defining the cytoskeletal anchoring mechanism: FRAP experiments showed 4.1N restricts IP3R1 lateral diffusion on the ER membrane in an actin-dependent manner, and domain-swap experiments with IP3R3 confirmed sufficiency of the 4.1N-binding sequence.\",\n      \"evidence\": \"FRAP in live hippocampal neurons, dominant-negative 4.1N, actin depolymerization, chimeric IP3R3\",\n      \"pmids\": [\"15364918\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Identity of the spectrin or actin isoform partner mediating ER-proximal anchoring is not determined\",\n        \"Whether diffusion restriction applies to other 4.1N-bound ER proteins is untested\"\n      ]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Establishing 4.1N as essential for activity-dependent AMPA receptor insertion and LTP: PKC phosphorylation of GluA1 at S816/S818 enhances 4.1N binding and drives membrane insertion events critical for LTP expression.\",\n      \"evidence\": \"Live imaging of individual insertion events, site-directed mutagenesis, co-IP, LTP electrophysiology in rodent hippocampal neurons\",\n      \"pmids\": [\"19503082\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether 4.1N also participates in GluA1 recycling/endocytosis during LTD is unknown\",\n        \"The vesicular compartment from which 4.1N-dependent insertion occurs is not identified\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Extending receptor anchoring to kainate receptors and nicotinic receptors: 4.1N regulates surface trafficking of GluK1/K2 and α7 AChR, with palmitoylation and PKC activity modulating these interactions, broadening 4.1N's role as a general receptor trafficking scaffold.\",\n      \"evidence\": \"Co-immunoprecipitation, surface biotinylation, palmitoylation-deficient mutants in brain slices (kainate); yeast two-hybrid, knockdown, membrane fractionation in PC12/hippocampal slices (α7 AChR)\",\n      \"pmids\": [\"23400781\", \"23256752\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Competition or cooperation among multiple receptor cargoes for 4.1N binding is not addressed\",\n        \"In vivo behavioral consequence of 4.1N loss on kainate or α7 AChR signaling is untested\"\n      ]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Revealing a tumor-suppressive mechanism: 4.1N recruits PP1 via its FERM domain to inactivate JNK–c-Jun signaling and interacts with flotillin-1 to suppress Wnt/β-catenin signaling in NSCLC cells, extending 4.1N function beyond neurons.\",\n      \"evidence\": \"Co-immunoprecipitation, PP1 activity assay, ectopic expression/knockdown, xenograft models in NSCLC cell lines\",\n      \"pmids\": [\"26575790\", \"27448302\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether PP1 recruitment is direct or mediated by a PP1-targeting subunit is unresolved\",\n        \"Relevance of JNK and Wnt pathway suppression to normal non-neuronal 4.1N physiology is unclear\"\n      ]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Identifying IP6K2 as a nuclear transport regulator and demonstrating 4.1N's role in cerebellar and reproductive physiology: IP6K2 binds 4.1N to enable nuclear translocation and regulate Purkinje cell morphology, while 4.1N knockout mice show hypothalamic–pituitary–gonadal axis failure with absent GnRH axonal transport.\",\n      \"evidence\": \"IP6K2 knockout mice with locomotor and cerebellar phenotypes; 4.1N knockout mice with reproductive organ atrophy and GnRH mislocalization; immunohistochemistry, electrophysiology\",\n      \"pmids\": [\"30006360\", \"33046791\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular cargo 4.1N transports along GnRH axons is undefined\",\n        \"Whether IP6K2-dependent nuclear translocation is the sole mechanism for 4.1N nuclear entry is unknown\",\n        \"Contribution of 4.1N loss in pituitary versus hypothalamus to reproductive failure is not dissected\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Demonstrating 4.1N suppresses anoikis resistance and EMT in ovarian cancer by promoting 14-3-3 degradation, revealing a non-neuronal scaffolding mechanism with direct relevance to metastasis.\",\n      \"evidence\": \"Co-immunoprecipitation, protein degradation assay, knockdown/overexpression, xenograft peritoneal dissemination model in epithelial ovarian cancer cells\",\n      \"pmids\": [\"32448967\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"E3 ligase or degradation pathway mediating 4.1N-induced 14-3-3 turnover is not identified\",\n        \"Whether this mechanism operates in normal epithelia is unknown\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Refining the synaptic plasticity mechanism: CaMKII phosphorylation of 4.1N drives formation of a pCaMKII–4.1N–GluA1 complex essential for LTP; 4.1N FERM domain (not CTD) supports synaptic function specifically in dentate gyrus granule neurons, revealing cell-type specificity.\",\n      \"evidence\": \"Co-IP for phospho-complexes, interfering peptides, CaMKII inhibitors, domain-deletion rescue, electrophysiology in hippocampal slices, cell-type-specific viral knockdown\",\n      \"pmids\": [\"37993087\", \"37845032\", \"37079350\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"CaMKII phosphorylation site(s) on 4.1N are not mapped\",\n        \"Why CA1 neurons are resistant to 4.1N loss while DG neurons are not is mechanistically unexplained\",\n        \"Whether FERM-domain-dependent synaptic role involves PP1 or other FERM interactors is untested\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Providing in vivo behavioral validation: disrupting the 4.1N–GluA1 interaction specifically in hippocampal CA1 impairs LTP and short-term spatial memory, confirming this interaction is required for cognitive function.\",\n      \"evidence\": \"Viral expression of GluA1 C80 interfering peptide in mouse CA1, LTP electrophysiology, Y-maze/Morris water maze behavioral testing\",\n      \"pmids\": [\"41417164\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Long-term memory and other hippocampus-dependent tasks beyond spatial memory are not assessed\",\n        \"Whether compensatory mechanisms involving other 4.1 family members mitigate the phenotype is unexplored\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include the structural basis of 4.1N's multi-receptor recognition, the identity of CaMKII phosphorylation sites on 4.1N, the mechanism governing cell-type-specific requirements (DG vs. CA1), and the molecular basis of 4.1N's roles in GnRH axonal transport and reproductive axis function.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No crystal or cryo-EM structure of 4.1N in complex with any receptor tail\",\n        \"CaMKII phosphorylation sites on 4.1N not mapped\",\n        \"Molecular mechanism of GnRH transport dependence on 4.1N not characterized\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2, 3, 7, 12, 14]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [5, 6, 14]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 8, 18]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 2, 7, 9, 12, 14]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [1, 4, 13]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [5, 6, 14]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [9, 16]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [0, 7, 15, 17, 21]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 8, 20]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [2, 3, 12, 16]}\n    ],\n    \"complexes\": [\n      \"IP3R1-4.1N-CASK-syndecan-2 complex\",\n      \"CaMKII-4.1N-GluA1 complex\"\n    ],\n    \"partners\": [\n      \"GRIA1\",\n      \"GRIK2\",\n      \"DRD2\",\n      \"ITPR1\",\n      \"NUMA1\",\n      \"AGAP2\",\n      \"IP6K2\",\n      \"PPP1CA\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}