{"gene":"ATP1B2","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":1990,"finding":"AMOG (ATP1B2) is a homologue of the β-subunit of Na,K-ATPase with 40% amino acid identity to the rat brain Na,K-ATPase β subunit. Immunoaffinity-purified AMOG was associated with a 100 kDa protein comprising the α2 (and possibly α3) isoforms of the Na,K-ATPase catalytic subunit, but not α1. A monoclonal anti-AMOG antibody that blocks adhesion increased ouabain-inhibitable 86Rb+ uptake in intact cultured astrocytes, demonstrating functional association with the Na,K-ATPase pump. AMOG-mediated adhesion occurred at 4°C and in the presence of ouabain, indicating adhesion is independent of Na,K-ATPase pump activity.","method":"cDNA sequencing, immunoaffinity purification, immunoprecipitation, 86Rb+ uptake assay, monoclonal antibody blocking","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — multiple orthogonal methods (sequencing, immunoaffinity purification, functional ion transport assay, blocking antibody) in a single rigorous study; foundational paper replicated by subsequent work","pmids":["1688561"],"is_preprint":false},{"year":1992,"finding":"AMOG/β2 expressed by cRNA injection in Xenopus oocytes assembles with endogenous Xenopus α1 or coexpressed Torpedo α1 subunits to form a functional α1/AMOG sodium pump isozyme, as demonstrated by ouabain binding site quantification and ouabain-sensitive 86Rb+ uptake. The α1/AMOG isozyme has slightly lower maximum transport rate and apparent affinity for external K+ than the α1/β1 isozyme. Immunoprecipitation from digitonin extracts confirmed stable association between AMOG and α1 subunits.","method":"Xenopus oocyte expression system, cRNA injection, ouabain binding assay, 86Rb+ uptake assay, immunoprecipitation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstitution in Xenopus oocytes with functional transport assay plus immunoprecipitation confirmation; directly validates pump function of AMOG/β2","pmids":["1383200"],"is_preprint":false},{"year":1993,"finding":"AMOG/β2, but not the β1 subunit of Na,K-ATPase, promotes neurite outgrowth when expressed on L-cells used as substrates for cerebellar and hippocampal neurons. This effect was specifically inhibited by anti-AMOG/β2 antibodies and a neuronal membrane fraction, and partially inhibited by the soluble recombinant extracellular domain of AMOG/β2, demonstrating that the extracellular domain mediates this function via an unknown neuronal receptor.","method":"Transfection of L-cells, neurite outgrowth assay, antibody blocking, recombinant extracellular domain inhibition","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean loss-of-function (antibody block) and domain-specific inhibition with recombinant protein, replicated across two neuron types; isoform specificity confirmed by β1 negative control","pmids":["7504672"],"is_preprint":false},{"year":1988,"finding":"Immunoaffinity-purified AMOG incorporated into liposomes binds specifically to neurons (including PC12 cells) but not to oligodendrocytes, astrocytes, or fibroblasts in cerebellar cultures. Binding was inhibited by Fab fragments of monoclonal AMOG antibodies (but not by L3 anti-carbohydrate antibodies), and was not blocked by antibodies to L1, N-CAM, or L2/HNK-1, demonstrating AMOG acts as an adhesion ligand for specific neuronal subpopulations via a distinct, independent mechanism.","method":"Liposome reconstitution assay, cell binding assay, Fab fragment inhibition","journal":"The Journal of neuroscience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional liposome reconstitution with antibody blocking controls; single lab, single study","pmids":["2457661"],"is_preprint":false},{"year":2003,"finding":"Re-expression of AMOG/β2 in AMOG/β2-negative C6 rat glioma cells by transfection increased cell adhesion and decreased migration on Matrigel compared to AMOG/β2-negative counterparts, demonstrating a direct role of AMOG/β2 in controlling glioma cell adhesion and invasion.","method":"Transfection/re-expression, Matrigel invasion assay, adhesion assay","journal":"Neuropathology and applied neurobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean gain-of-function in defined cell system with functional readouts; single lab","pmids":["12887597"],"is_preprint":false},{"year":2013,"finding":"Overexpression of AMOG in GBM cells decreased invasion without affecting migration or proliferation, while knockdown of AMOG in normal human astrocytes increased invasion, establishing a direct role for AMOG/β2 in suppressing glioma invasion.","method":"Overexpression and siRNA knockdown, Matrigel invasion assay, scratch assay, direct cell counting","journal":"Neuro-oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — bidirectional loss- and gain-of-function with specific phenotypic readout; single lab, single study","pmids":["23887941"],"is_preprint":false},{"year":2019,"finding":"In cerebellar granule precursor cells, β2-subunit (AMOG) knockdown resulted in increased Merlin/NF2 expression, increased YAP phosphorylation, and decreased N-Ras expression, demonstrating that β2-subunit negatively regulates Merlin/NF2 and thereby modulates Hippo/YAP signaling. β2 knockdown also altered EGFR signaling kinetics in a Merlin-dependent manner and impaired EGF-induced actin cytoskeleton reorganization. Isoform specificity was confirmed: β1 knockdown did not replicate these effects.","method":"siRNA knockdown, immunoblotting, EGF stimulation assays, actin cytoskeleton imaging","journal":"Molecular neurobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — specific knockdown with multiple downstream readouts and isoform-specificity control; single lab, single study","pmids":["31062247"],"is_preprint":false},{"year":2019,"finding":"Reduction of AMOG expression in human glioblastoma cells (U-87 MG, U251, SHG44) elevated L1CAM expression, accompanied by decreased cell apoptosis and senescence, establishing an inverse regulatory relationship between AMOG and L1CAM expression in glioma cells.","method":"siRNA knockdown, immunoblotting, flow cytometry (apoptosis/senescence assays)","journal":"BMC cancer","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function in multiple cell lines with defined molecular and cellular phenotypic readouts; single lab","pmids":["31510944"],"is_preprint":false},{"year":1996,"finding":"Disruption of the AMOG/β2 gene in mice leads to apoptotic (TUNEL-positive, ultrastructurally confirmed) death of photoreceptor cells in the retina beginning around postnatal day 9 and massively by day 16, correlated with elevated GFAP in retinal astrocytes and ectopic GFAP in Müller cells, while other retinal cell types are unaffected.","method":"AMOG/β2 knockout mice, TUNEL labeling, electron microscopy, immunohistochemistry","journal":"Journal of neurocytology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic knockout with TUNEL and ultrastructural confirmation of apoptosis; single study but uses multiple orthogonal methods","pmids":["8793730"],"is_preprint":false},{"year":2022,"finding":"The glycosylated extracellular domain of human β2/AMOG can form energetically stable trans-interacting homodimers. CHO fibroblasts transfected with β2 formed larger cell aggregates than controls; tunicamycin treatment reduced aggregation, implicating N-glycans. Protein-protein interaction assays in MDCK and CHO cells showed β2 subunits on the cell surface interact with each other in trans, establishing β2/AMOG as a homophilic adhesion molecule.","method":"Protein docking (in silico), cell-cell aggregation assay, protein-protein interaction assay (co-culture with differentially tagged constructs), tunicamycin treatment","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cell-based aggregation assay plus in vivo protein-protein interaction assay with glycosylation perturbation; single lab, computational docking supporting but not confirming structure","pmids":["35887102"],"is_preprint":false},{"year":1992,"finding":"The cis-acting positive regulatory element AMRE (sequence GAGGCGGGG at positions -87 to -79) in the rat AMOG/Na,K-ATPase β2 subunit gene promoter enhances promoter activity and acts in a mutually compensating manner with an Sp1 element at -147 to -142, as demonstrated by transient transfection assays in multiple cell lines.","method":"Transient transfection assay, promoter deletion/mutation analysis","journal":"Journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional promoter dissection with defined element and compensatory interaction identified; single lab","pmids":["1377671"],"is_preprint":false},{"year":2017,"finding":"A SINE insertion (227 bp) into the ATP1B2 gene in Belgian Shepherd (Malinois) dogs causes aberrant RNA splicing, reduced ATP1B2 protein expression in the CNS, and results in spongy degeneration with cerebellar ataxia (SDCA2), a phenotype similar to Atp1b2 knockout mice.","method":"Linkage and homozygosity mapping, whole-genome sequencing, RT-PCR (aberrant splicing), immunohistochemistry","journal":"G3 (Bethesda, Md.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — naturally occurring loss-of-function with molecular validation of aberrant splicing and protein reduction; single study","pmids":["28620085"],"is_preprint":false},{"year":2025,"finding":"In Atp1b2 knock-in mice (expressing β1 instead of β2 under Atp1b2 regulatory elements), cones degenerate rapidly (absent by 4 months) while rods degenerate slowly, demonstrating that β2 is specifically required for cone photoreceptor survival and cannot be fully replaced by β1. Levels of retinoschisin, a secreted retina-specific protein that directly interacts with the β2-subunit, were greatly reduced in mutant retinas, linking β2 to retinoschisin-dependent signaling.","method":"Knock-in mouse model, immunohistochemistry, in situ hybridization, cell counting","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic knock-in model with multiple cell-type-specific phenotypic readouts and molecular marker validation; single study","pmids":["40558505"],"is_preprint":false},{"year":2017,"finding":"The ACSA-2 antibody epitope was identified as ATP1B2 by overexpression and knockdown assays, immunoblotting, and immunohistochemistry, establishing ATP1B2 as a cell surface marker of astrocytes in adult mouse brain that is stably expressed across multiple CNS injury and disease models.","method":"Overexpression, siRNA knockdown, immunoblotting, immunohistochemistry, single-cell sequencing","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal validation methods for epitope identification; single lab","pmids":["28373281"],"is_preprint":false}],"current_model":"ATP1B2 (AMOG) is the β2 isoform of the Na,K-ATPase, which associates preferentially with the α2/α3 catalytic subunits to form a functional ion pump with slightly lower K+ affinity than α/β1; its extracellular domain acts as a Ca2+-independent adhesion molecule that binds specific neuronal subpopulations (including via homophilic β2–β2 trans-dimers, N-glycan-dependent), promotes neurite outgrowth through an unidentified neuronal receptor, suppresses glioma invasion, and negatively regulates Merlin/NF2–Hippo/YAP signaling in cerebellar granule cells, while loss of β2 in vivo causes astrocyte endfeet swelling, apoptotic photoreceptor degeneration (cones more than rods), and cerebellar ataxia."},"narrative":{"mechanistic_narrative":"ATP1B2 (AMOG) is the β2 isoform of the Na,K-ATPase β-subunit, functioning both as an obligate auxiliary subunit of the ion pump and as a cell-surface adhesion molecule in the nervous system [PMID:1688561, PMID:1383200]. It assembles stably with the α catalytic subunit — preferentially α2/α3 but not α1 in astrocytes — to form a functional sodium pump; reconstitution with α1 in Xenopus oocytes yields an active ouabain-sensitive isozyme with slightly lower maximal transport rate and external K+ affinity than the α1/β1 pump [PMID:1688561, PMID:1383200]. Independent of pump activity, the glycosylated extracellular domain of β2 mediates Ca2+-independent adhesion: it binds specific neuronal subpopulations through a distinct mechanism unrelated to L1, N-CAM or HNK-1 [PMID:2457661], forms N-glycan-dependent homophilic trans-dimers [PMID:35887102], and promotes neurite outgrowth via an unidentified neuronal receptor in an isoform-specific manner not replicated by β1 [PMID:7504672]. In glioma cells, re-expression of β2 increases adhesion and suppresses invasion, while its loss in astrocytes enhances invasion, linking it to control of cell motility [PMID:12887597, PMID:23887941]; β2 also negatively regulates Merlin/NF2 to modulate Hippo/YAP and EGFR signaling in cerebellar granule precursors [PMID:31062247]. In vivo loss or non-replaceable substitution of β2 causes apoptotic photoreceptor degeneration—cones more severely than rods—associated with reduced retinoschisin, a secreted retinal protein that interacts with β2 [PMID:8793730, PMID:40558505], and the canine SINE-insertion loss-of-function allele causes spongy degeneration with cerebellar ataxia (SDCA2) [PMID:28620085]. ATP1B2 is the ACSA-2 epitope and serves as a stable astrocyte cell-surface marker in adult mouse brain [PMID:28373281].","teleology":[{"year":1988,"claim":"Established that AMOG is a neuron-selective adhesion ligand, defining its activity as distinct from the major known neural adhesion systems.","evidence":"Liposome reconstitution and cell-binding assays with Fab fragment blocking in cerebellar cultures","pmids":["2457661"],"confidence":"Medium","gaps":["Neuronal receptor for AMOG not identified","Single lab, single study"]},{"year":1990,"claim":"Identified AMOG as a Na,K-ATPase β-subunit homologue physically associated with the α2/α3 (not α1) catalytic subunit, and showed its adhesion function is independent of pump activity.","evidence":"cDNA sequencing, immunoaffinity purification, 86Rb+ uptake, blocking antibody in astrocytes","pmids":["1688561"],"confidence":"High","gaps":["Structural basis of α-isoform selectivity not resolved","Adhesion receptor unidentified"]},{"year":1992,"claim":"Demonstrated AMOG/β2 is a functional pump subunit by reconstituting an active α1/β2 isozyme, and characterized the promoter elements controlling its expression.","evidence":"Xenopus oocyte cRNA expression, ouabain binding and 86Rb+ uptake, immunoprecipitation; promoter deletion/mutation transfection assays","pmids":["1383200","1377671"],"confidence":"High","gaps":["Functional consequence of altered K+ affinity in vivo unknown","Transcription factors binding AMRE not identified"]},{"year":1993,"claim":"Established that the β2 extracellular domain promotes neurite outgrowth, separating this adhesion-linked function from the β1 isoform.","evidence":"L-cell substrate transfection, neurite outgrowth assay, antibody and recombinant ECD blocking","pmids":["7504672"],"confidence":"High","gaps":["Neuronal receptor mediating outgrowth unidentified","Signaling downstream of receptor unknown"]},{"year":1996,"claim":"Showed in vivo that β2 loss causes selective apoptotic photoreceptor death with reactive gliosis, establishing a non-redundant role in retinal cell survival.","evidence":"Atp1b2 knockout mice, TUNEL, electron microscopy, immunohistochemistry","pmids":["8793730"],"confidence":"Medium","gaps":["Molecular mechanism linking β2 loss to photoreceptor apoptosis not defined","Cell-autonomous vs glial contribution unresolved"]},{"year":2003,"claim":"Demonstrated a direct role for β2 in restraining glioma cell motility via increased adhesion.","evidence":"Re-expression in C6 glioma cells, Matrigel invasion and adhesion assays","pmids":["12887597"],"confidence":"Medium","gaps":["Mechanism coupling β2 adhesion to reduced migration unknown","Single lab"]},{"year":2013,"claim":"Confirmed bidirectionally that β2 suppresses invasion in human glioma and astrocytes, separating this from migration and proliferation.","evidence":"Overexpression and siRNA knockdown, Matrigel invasion, scratch assay, cell counting","pmids":["23887941"],"confidence":"Medium","gaps":["Downstream effectors of invasion suppression not defined","Single lab"]},{"year":2017,"claim":"Linked a natural ATP1B2 loss-of-function allele to cerebellar disease in dogs and identified ATP1B2 as the ACSA-2 astrocyte surface marker.","evidence":"Canine WGS/linkage, RT-PCR splicing analysis, IHC (SDCA2); ACSA-2 epitope mapping by overexpression/knockdown, immunoblot, scRNA-seq","pmids":["28620085","28373281"],"confidence":"Medium","gaps":["Mechanism connecting protein reduction to spongy degeneration not defined","Human disease equivalent not established in timeline"]},{"year":2019,"claim":"Defined β2 as a negative regulator of Merlin/NF2–Hippo/YAP and EGFR signaling and uncovered an inverse relationship with L1CAM in glioma.","evidence":"siRNA knockdown, immunoblotting, EGF stimulation, actin imaging in granule precursors; knockdown with apoptosis/senescence assays in glioblastoma lines","pmids":["31062247","31510944"],"confidence":"Medium","gaps":["Direct molecular link between β2 and Merlin not established","Mechanism of L1CAM regulation unknown"]},{"year":2022,"claim":"Established β2 as a homophilic adhesion molecule whose extracellular domain forms N-glycan-dependent trans-dimers.","evidence":"In silico docking, cell aggregation assays, trans-interaction assays with tunicamycin perturbation in CHO/MDCK cells","pmids":["35887102"],"confidence":"Medium","gaps":["No experimental structure of the dimer","Computational docking not structurally confirmed"]},{"year":2025,"claim":"Showed β2 is specifically required for cone survival and cannot be functionally replaced by β1, and linked it to retinoschisin.","evidence":"Atp1b2 β1 knock-in mice, IHC, in situ hybridization, cell counting","pmids":["40558505"],"confidence":"Medium","gaps":["Mechanism of β2–retinoschisin functional coupling not defined","Why cones are more vulnerable than rods unresolved"]},{"year":null,"claim":"The identity of the neuronal receptor mediating β2-dependent adhesion and neurite outgrowth, and the direct biochemical mechanisms linking β2 to Merlin/NF2 and retinoschisin, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No neuronal binding partner identified","Direct β2–Merlin interaction not demonstrated","Mechanism of cell-type-specific photoreceptor degeneration unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098631","term_label":"cell adhesion mediator activity","supporting_discovery_ids":[3,9,2]},{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[0,1]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,9,13]}],"pathway":[{"term_id":"R-HSA-382551","term_label":"Transport of small molecules","supporting_discovery_ids":[0,1]},{"term_id":"R-HSA-1500931","term_label":"Cell-Cell communication","supporting_discovery_ids":[3,9]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[6]}],"complexes":["Na,K-ATPase"],"partners":["ATP1A2","ATP1A3","ATP1A1","RS1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P14415","full_name":"Sodium/potassium-transporting ATPase subunit beta-2","aliases":["Adhesion molecule in glia","AMOG","Sodium/potassium-dependent ATPase subunit beta-2"],"length_aa":290,"mass_kda":33.4,"function":"This is the non-catalytic component of the active enzyme, which catalyzes the hydrolysis of ATP coupled with the exchange of Na(+) and K(+) ions across the plasma membrane. The exact function of the beta-2 subunit is not known Mediates cell adhesion of neurons and astrocytes, and promotes neurite outgrowth","subcellular_location":"Cell membrane","url":"https://www.uniprot.org/uniprotkb/P14415/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ATP1B2","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CANX","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/ATP1B2","total_profiled":1310},"omim":[{"mim_id":"609739","title":"IMMUNOGLOBULIN-LIKE DOMAIN-CONTAINING RECEPTOR 1; ILDR1","url":"https://www.omim.org/entry/609739"},{"mim_id":"601867","title":"ATPase, Na+/K+ TRANSPORTING, BETA-3 POLYPEPTIDE; ATP1B3","url":"https://www.omim.org/entry/601867"},{"mim_id":"182350","title":"ATPase, Na+/K+ TRANSPORTING, ALPHA-3 POLYPEPTIDE; ATP1A3","url":"https://www.omim.org/entry/182350"},{"mim_id":"182331","title":"ATPase, Na+/K+ TRANSPORTING, BETA-2 POLYPEPTIDE; ATP1B2","url":"https://www.omim.org/entry/182331"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Group enriched","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"brain","ntpm":290.0},{"tissue":"retina","ntpm":570.1}],"url":"https://www.proteinatlas.org/search/ATP1B2"},"hgnc":{"alias_symbol":["AMOG"],"prev_symbol":[]},"alphafold":{"accession":"P14415","domains":[{"cath_id":"2.60.40.1660","chopping":"81-287","consensus_level":"high","plddt":91.1782,"start":81,"end":287}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P14415","model_url":"https://alphafold.ebi.ac.uk/files/AF-P14415-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P14415-F1-predicted_aligned_error_v6.png","plddt_mean":89.88},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ATP1B2","jax_strain_url":"https://www.jax.org/strain/search?query=ATP1B2"},"sequence":{"accession":"P14415","fasta_url":"https://rest.uniprot.org/uniprotkb/P14415.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P14415/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P14415"}},"corpus_meta":[{"pmid":"1688561","id":"PMC_1688561","title":"The adhesion molecule on glia (AMOG) is a homologue of the beta subunit of the Na,K-ATPase.","date":"1990","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/1688561","citation_count":348,"is_preprint":false},{"pmid":"1383200","id":"PMC_1383200","title":"The adhesion molecule on glia (AMOG/beta 2) and alpha 1 subunits assemble to functional sodium pumps in Xenopus oocytes.","date":"1992","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/1383200","citation_count":81,"is_preprint":false},{"pmid":"28373281","id":"PMC_28373281","title":"An immunoaffinity-based method for isolating ultrapure adult astrocytes based on ATP1B2 targeting by the ACSA-2 antibody.","date":"2017","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/28373281","citation_count":76,"is_preprint":false},{"pmid":"7504672","id":"PMC_7504672","title":"Functional characterization of beta isoforms of murine Na,K-ATPase. The adhesion molecule on glia (AMOG/beta 2), but not beta 1, promotes neurite outgrowth.","date":"1993","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/7504672","citation_count":62,"is_preprint":false},{"pmid":"19371356","id":"PMC_19371356","title":"Pi3K-mTOR signaling and AMOG expression in epilepsy-associated glioneuronal tumors.","date":"2009","source":"Brain pathology (Zurich, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/19371356","citation_count":59,"is_preprint":false},{"pmid":"8736577","id":"PMC_8736577","title":"Expression of the beta 1 and beta 2(AMOG) subunits of the Na,K-ATPase in neural tissues: cellular and developmental distribution patterns.","date":"1996","source":"Brain research bulletin","url":"https://pubmed.ncbi.nlm.nih.gov/8736577","citation_count":50,"is_preprint":false},{"pmid":"2457661","id":"PMC_2457661","title":"The adhesion molecule on glia (AMOG) incorporated into lipid vesicles binds to subpopulations of 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characterization of the cis-elements regulating the rat AMOG (adhesion molecule on glia)/Na,K-ATPase beta 2 subunit gene.","date":"1992","source":"Journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/1377671","citation_count":12,"is_preprint":false},{"pmid":"31062247","id":"PMC_31062247","title":"A Functional Interaction Between Na,K-ATPase β2-Subunit/AMOG and NF2/Merlin Regulates Growth Factor Signaling in Cerebellar Granule Cells.","date":"2019","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/31062247","citation_count":11,"is_preprint":false},{"pmid":"1699290","id":"PMC_1699290","title":"Assignment of Amog (adhesion molecule on glia) gene to mouse chromosome 11 near Zfp-3 and Asgr-1,2 and to human chromosome 17.","date":"1990","source":"Somatic cell and molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/1699290","citation_count":11,"is_preprint":false},{"pmid":"35887102","id":"PMC_35887102","title":"The β2-Subunit (AMOG) of Human Na+, 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sciences","url":"https://pubmed.ncbi.nlm.nih.gov/40943664","citation_count":0,"is_preprint":false},{"pmid":"40558505","id":"PMC_40558505","title":"Atp1b2 Knock-In Mice Exhibit a Cone-Rod Dystrophy-Like Phenotype.","date":"2025","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/40558505","citation_count":0,"is_preprint":false},{"pmid":"7534017","id":"PMC_7534017","title":"[Morphology and development of neural transplants of AMOG-deficient mice].","date":"1994","source":"Verhandlungen der Deutschen Gesellschaft fur Pathologie","url":"https://pubmed.ncbi.nlm.nih.gov/7534017","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.11.07.685575","title":"Cell surface markers identify astrocyte subpopulations in the adult hippocampus with a heterogeneous response to aging","date":"2025-11-09","source":"bioRxiv","url":"https://doi.org/10.1101/2025.11.07.685575","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.05.18.25327658","title":"Minimalistic Transcriptomic Signatures Permit Accurate Early Prediction of COVID-19 Mortality","date":"2025-05-19","source":"bioRxiv","url":"https://doi.org/10.1101/2025.05.18.25327658","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.08.13.607722","title":"<i>In Silico</i>  studies provide new structural insights into  <i>trans</i>  -dimerization of β  <sub>1</sub>  and β  <sub>2</sub>  subunits of the Na  <sup>+</sup>  ,K  <sup>+</sup>  -ATPase","date":"2024-08-16","source":"bioRxiv","url":"https://doi.org/10.1101/2024.08.13.607722","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.09.23.24314250","title":"Longitudinal Monitoring of Glioblastoma Small Extracellular Vesicle Evolution Using a Nanodiagnostic to Detect Emergence of Glioma Stem Cells Driving Recurrent Disease","date":"2024-09-24","source":"bioRxiv","url":"https://doi.org/10.1101/2024.09.23.24314250","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":18222,"output_tokens":3772,"usd":0.055623,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11631,"output_tokens":3483,"usd":0.072615,"stage2_stop_reason":"end_turn"},"total_usd":0.128238,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1990,\n      \"finding\": \"AMOG (ATP1B2) is a homologue of the β-subunit of Na,K-ATPase with 40% amino acid identity to the rat brain Na,K-ATPase β subunit. Immunoaffinity-purified AMOG was associated with a 100 kDa protein comprising the α2 (and possibly α3) isoforms of the Na,K-ATPase catalytic subunit, but not α1. A monoclonal anti-AMOG antibody that blocks adhesion increased ouabain-inhibitable 86Rb+ uptake in intact cultured astrocytes, demonstrating functional association with the Na,K-ATPase pump. AMOG-mediated adhesion occurred at 4°C and in the presence of ouabain, indicating adhesion is independent of Na,K-ATPase pump activity.\",\n      \"method\": \"cDNA sequencing, immunoaffinity purification, immunoprecipitation, 86Rb+ uptake assay, monoclonal antibody blocking\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — multiple orthogonal methods (sequencing, immunoaffinity purification, functional ion transport assay, blocking antibody) in a single rigorous study; foundational paper replicated by subsequent work\",\n      \"pmids\": [\"1688561\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"AMOG/β2 expressed by cRNA injection in Xenopus oocytes assembles with endogenous Xenopus α1 or coexpressed Torpedo α1 subunits to form a functional α1/AMOG sodium pump isozyme, as demonstrated by ouabain binding site quantification and ouabain-sensitive 86Rb+ uptake. The α1/AMOG isozyme has slightly lower maximum transport rate and apparent affinity for external K+ than the α1/β1 isozyme. Immunoprecipitation from digitonin extracts confirmed stable association between AMOG and α1 subunits.\",\n      \"method\": \"Xenopus oocyte expression system, cRNA injection, ouabain binding assay, 86Rb+ uptake assay, immunoprecipitation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstitution in Xenopus oocytes with functional transport assay plus immunoprecipitation confirmation; directly validates pump function of AMOG/β2\",\n      \"pmids\": [\"1383200\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1993,\n      \"finding\": \"AMOG/β2, but not the β1 subunit of Na,K-ATPase, promotes neurite outgrowth when expressed on L-cells used as substrates for cerebellar and hippocampal neurons. This effect was specifically inhibited by anti-AMOG/β2 antibodies and a neuronal membrane fraction, and partially inhibited by the soluble recombinant extracellular domain of AMOG/β2, demonstrating that the extracellular domain mediates this function via an unknown neuronal receptor.\",\n      \"method\": \"Transfection of L-cells, neurite outgrowth assay, antibody blocking, recombinant extracellular domain inhibition\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean loss-of-function (antibody block) and domain-specific inhibition with recombinant protein, replicated across two neuron types; isoform specificity confirmed by β1 negative control\",\n      \"pmids\": [\"7504672\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1988,\n      \"finding\": \"Immunoaffinity-purified AMOG incorporated into liposomes binds specifically to neurons (including PC12 cells) but not to oligodendrocytes, astrocytes, or fibroblasts in cerebellar cultures. Binding was inhibited by Fab fragments of monoclonal AMOG antibodies (but not by L3 anti-carbohydrate antibodies), and was not blocked by antibodies to L1, N-CAM, or L2/HNK-1, demonstrating AMOG acts as an adhesion ligand for specific neuronal subpopulations via a distinct, independent mechanism.\",\n      \"method\": \"Liposome reconstitution assay, cell binding assay, Fab fragment inhibition\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional liposome reconstitution with antibody blocking controls; single lab, single study\",\n      \"pmids\": [\"2457661\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Re-expression of AMOG/β2 in AMOG/β2-negative C6 rat glioma cells by transfection increased cell adhesion and decreased migration on Matrigel compared to AMOG/β2-negative counterparts, demonstrating a direct role of AMOG/β2 in controlling glioma cell adhesion and invasion.\",\n      \"method\": \"Transfection/re-expression, Matrigel invasion assay, adhesion assay\",\n      \"journal\": \"Neuropathology and applied neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean gain-of-function in defined cell system with functional readouts; single lab\",\n      \"pmids\": [\"12887597\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Overexpression of AMOG in GBM cells decreased invasion without affecting migration or proliferation, while knockdown of AMOG in normal human astrocytes increased invasion, establishing a direct role for AMOG/β2 in suppressing glioma invasion.\",\n      \"method\": \"Overexpression and siRNA knockdown, Matrigel invasion assay, scratch assay, direct cell counting\",\n      \"journal\": \"Neuro-oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — bidirectional loss- and gain-of-function with specific phenotypic readout; single lab, single study\",\n      \"pmids\": [\"23887941\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In cerebellar granule precursor cells, β2-subunit (AMOG) knockdown resulted in increased Merlin/NF2 expression, increased YAP phosphorylation, and decreased N-Ras expression, demonstrating that β2-subunit negatively regulates Merlin/NF2 and thereby modulates Hippo/YAP signaling. β2 knockdown also altered EGFR signaling kinetics in a Merlin-dependent manner and impaired EGF-induced actin cytoskeleton reorganization. Isoform specificity was confirmed: β1 knockdown did not replicate these effects.\",\n      \"method\": \"siRNA knockdown, immunoblotting, EGF stimulation assays, actin cytoskeleton imaging\",\n      \"journal\": \"Molecular neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — specific knockdown with multiple downstream readouts and isoform-specificity control; single lab, single study\",\n      \"pmids\": [\"31062247\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Reduction of AMOG expression in human glioblastoma cells (U-87 MG, U251, SHG44) elevated L1CAM expression, accompanied by decreased cell apoptosis and senescence, establishing an inverse regulatory relationship between AMOG and L1CAM expression in glioma cells.\",\n      \"method\": \"siRNA knockdown, immunoblotting, flow cytometry (apoptosis/senescence assays)\",\n      \"journal\": \"BMC cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function in multiple cell lines with defined molecular and cellular phenotypic readouts; single lab\",\n      \"pmids\": [\"31510944\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Disruption of the AMOG/β2 gene in mice leads to apoptotic (TUNEL-positive, ultrastructurally confirmed) death of photoreceptor cells in the retina beginning around postnatal day 9 and massively by day 16, correlated with elevated GFAP in retinal astrocytes and ectopic GFAP in Müller cells, while other retinal cell types are unaffected.\",\n      \"method\": \"AMOG/β2 knockout mice, TUNEL labeling, electron microscopy, immunohistochemistry\",\n      \"journal\": \"Journal of neurocytology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic knockout with TUNEL and ultrastructural confirmation of apoptosis; single study but uses multiple orthogonal methods\",\n      \"pmids\": [\"8793730\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"The glycosylated extracellular domain of human β2/AMOG can form energetically stable trans-interacting homodimers. CHO fibroblasts transfected with β2 formed larger cell aggregates than controls; tunicamycin treatment reduced aggregation, implicating N-glycans. Protein-protein interaction assays in MDCK and CHO cells showed β2 subunits on the cell surface interact with each other in trans, establishing β2/AMOG as a homophilic adhesion molecule.\",\n      \"method\": \"Protein docking (in silico), cell-cell aggregation assay, protein-protein interaction assay (co-culture with differentially tagged constructs), tunicamycin treatment\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cell-based aggregation assay plus in vivo protein-protein interaction assay with glycosylation perturbation; single lab, computational docking supporting but not confirming structure\",\n      \"pmids\": [\"35887102\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"The cis-acting positive regulatory element AMRE (sequence GAGGCGGGG at positions -87 to -79) in the rat AMOG/Na,K-ATPase β2 subunit gene promoter enhances promoter activity and acts in a mutually compensating manner with an Sp1 element at -147 to -142, as demonstrated by transient transfection assays in multiple cell lines.\",\n      \"method\": \"Transient transfection assay, promoter deletion/mutation analysis\",\n      \"journal\": \"Journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional promoter dissection with defined element and compensatory interaction identified; single lab\",\n      \"pmids\": [\"1377671\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"A SINE insertion (227 bp) into the ATP1B2 gene in Belgian Shepherd (Malinois) dogs causes aberrant RNA splicing, reduced ATP1B2 protein expression in the CNS, and results in spongy degeneration with cerebellar ataxia (SDCA2), a phenotype similar to Atp1b2 knockout mice.\",\n      \"method\": \"Linkage and homozygosity mapping, whole-genome sequencing, RT-PCR (aberrant splicing), immunohistochemistry\",\n      \"journal\": \"G3 (Bethesda, Md.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — naturally occurring loss-of-function with molecular validation of aberrant splicing and protein reduction; single study\",\n      \"pmids\": [\"28620085\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In Atp1b2 knock-in mice (expressing β1 instead of β2 under Atp1b2 regulatory elements), cones degenerate rapidly (absent by 4 months) while rods degenerate slowly, demonstrating that β2 is specifically required for cone photoreceptor survival and cannot be fully replaced by β1. Levels of retinoschisin, a secreted retina-specific protein that directly interacts with the β2-subunit, were greatly reduced in mutant retinas, linking β2 to retinoschisin-dependent signaling.\",\n      \"method\": \"Knock-in mouse model, immunohistochemistry, in situ hybridization, cell counting\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic knock-in model with multiple cell-type-specific phenotypic readouts and molecular marker validation; single study\",\n      \"pmids\": [\"40558505\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"The ACSA-2 antibody epitope was identified as ATP1B2 by overexpression and knockdown assays, immunoblotting, and immunohistochemistry, establishing ATP1B2 as a cell surface marker of astrocytes in adult mouse brain that is stably expressed across multiple CNS injury and disease models.\",\n      \"method\": \"Overexpression, siRNA knockdown, immunoblotting, immunohistochemistry, single-cell sequencing\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal validation methods for epitope identification; single lab\",\n      \"pmids\": [\"28373281\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ATP1B2 (AMOG) is the β2 isoform of the Na,K-ATPase, which associates preferentially with the α2/α3 catalytic subunits to form a functional ion pump with slightly lower K+ affinity than α/β1; its extracellular domain acts as a Ca2+-independent adhesion molecule that binds specific neuronal subpopulations (including via homophilic β2–β2 trans-dimers, N-glycan-dependent), promotes neurite outgrowth through an unidentified neuronal receptor, suppresses glioma invasion, and negatively regulates Merlin/NF2–Hippo/YAP signaling in cerebellar granule cells, while loss of β2 in vivo causes astrocyte endfeet swelling, apoptotic photoreceptor degeneration (cones more than rods), and cerebellar ataxia.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ATP1B2 (AMOG) is the β2 isoform of the Na,K-ATPase β-subunit, functioning both as an obligate auxiliary subunit of the ion pump and as a cell-surface adhesion molecule in the nervous system [#0, #1]. It assembles stably with the α catalytic subunit — preferentially α2/α3 but not α1 in astrocytes — to form a functional sodium pump; reconstitution with α1 in Xenopus oocytes yields an active ouabain-sensitive isozyme with slightly lower maximal transport rate and external K+ affinity than the α1/β1 pump [#0, #1]. Independent of pump activity, the glycosylated extracellular domain of β2 mediates Ca2+-independent adhesion: it binds specific neuronal subpopulations through a distinct mechanism unrelated to L1, N-CAM or HNK-1 [#3], forms N-glycan-dependent homophilic trans-dimers [#9], and promotes neurite outgrowth via an unidentified neuronal receptor in an isoform-specific manner not replicated by β1 [#2]. In glioma cells, re-expression of β2 increases adhesion and suppresses invasion, while its loss in astrocytes enhances invasion, linking it to control of cell motility [#4, #5]; β2 also negatively regulates Merlin/NF2 to modulate Hippo/YAP and EGFR signaling in cerebellar granule precursors [#6]. In vivo loss or non-replaceable substitution of β2 causes apoptotic photoreceptor degeneration—cones more severely than rods—associated with reduced retinoschisin, a secreted retinal protein that interacts with β2 [#8, #12], and the canine SINE-insertion loss-of-function allele causes spongy degeneration with cerebellar ataxia (SDCA2) [#11]. ATP1B2 is the ACSA-2 epitope and serves as a stable astrocyte cell-surface marker in adult mouse brain [#13].\",\n  \"teleology\": [\n    {\n      \"year\": 1988,\n      \"claim\": \"Established that AMOG is a neuron-selective adhesion ligand, defining its activity as distinct from the major known neural adhesion systems.\",\n      \"evidence\": \"Liposome reconstitution and cell-binding assays with Fab fragment blocking in cerebellar cultures\",\n      \"pmids\": [\"2457661\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Neuronal receptor for AMOG not identified\", \"Single lab, single study\"]\n    },\n    {\n      \"year\": 1990,\n      \"claim\": \"Identified AMOG as a Na,K-ATPase β-subunit homologue physically associated with the α2/α3 (not α1) catalytic subunit, and showed its adhesion function is independent of pump activity.\",\n      \"evidence\": \"cDNA sequencing, immunoaffinity purification, 86Rb+ uptake, blocking antibody in astrocytes\",\n      \"pmids\": [\"1688561\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of α-isoform selectivity not resolved\", \"Adhesion receptor unidentified\"]\n    },\n    {\n      \"year\": 1992,\n      \"claim\": \"Demonstrated AMOG/β2 is a functional pump subunit by reconstituting an active α1/β2 isozyme, and characterized the promoter elements controlling its expression.\",\n      \"evidence\": \"Xenopus oocyte cRNA expression, ouabain binding and 86Rb+ uptake, immunoprecipitation; promoter deletion/mutation transfection assays\",\n      \"pmids\": [\"1383200\", \"1377671\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of altered K+ affinity in vivo unknown\", \"Transcription factors binding AMRE not identified\"]\n    },\n    {\n      \"year\": 1993,\n      \"claim\": \"Established that the β2 extracellular domain promotes neurite outgrowth, separating this adhesion-linked function from the β1 isoform.\",\n      \"evidence\": \"L-cell substrate transfection, neurite outgrowth assay, antibody and recombinant ECD blocking\",\n      \"pmids\": [\"7504672\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Neuronal receptor mediating outgrowth unidentified\", \"Signaling downstream of receptor unknown\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Showed in vivo that β2 loss causes selective apoptotic photoreceptor death with reactive gliosis, establishing a non-redundant role in retinal cell survival.\",\n      \"evidence\": \"Atp1b2 knockout mice, TUNEL, electron microscopy, immunohistochemistry\",\n      \"pmids\": [\"8793730\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism linking β2 loss to photoreceptor apoptosis not defined\", \"Cell-autonomous vs glial contribution unresolved\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Demonstrated a direct role for β2 in restraining glioma cell motility via increased adhesion.\",\n      \"evidence\": \"Re-expression in C6 glioma cells, Matrigel invasion and adhesion assays\",\n      \"pmids\": [\"12887597\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism coupling β2 adhesion to reduced migration unknown\", \"Single lab\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Confirmed bidirectionally that β2 suppresses invasion in human glioma and astrocytes, separating this from migration and proliferation.\",\n      \"evidence\": \"Overexpression and siRNA knockdown, Matrigel invasion, scratch assay, cell counting\",\n      \"pmids\": [\"23887941\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Downstream effectors of invasion suppression not defined\", \"Single lab\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Linked a natural ATP1B2 loss-of-function allele to cerebellar disease in dogs and identified ATP1B2 as the ACSA-2 astrocyte surface marker.\",\n      \"evidence\": \"Canine WGS/linkage, RT-PCR splicing analysis, IHC (SDCA2); ACSA-2 epitope mapping by overexpression/knockdown, immunoblot, scRNA-seq\",\n      \"pmids\": [\"28620085\", \"28373281\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism connecting protein reduction to spongy degeneration not defined\", \"Human disease equivalent not established in timeline\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Defined β2 as a negative regulator of Merlin/NF2–Hippo/YAP and EGFR signaling and uncovered an inverse relationship with L1CAM in glioma.\",\n      \"evidence\": \"siRNA knockdown, immunoblotting, EGF stimulation, actin imaging in granule precursors; knockdown with apoptosis/senescence assays in glioblastoma lines\",\n      \"pmids\": [\"31062247\", \"31510944\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular link between β2 and Merlin not established\", \"Mechanism of L1CAM regulation unknown\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Established β2 as a homophilic adhesion molecule whose extracellular domain forms N-glycan-dependent trans-dimers.\",\n      \"evidence\": \"In silico docking, cell aggregation assays, trans-interaction assays with tunicamycin perturbation in CHO/MDCK cells\",\n      \"pmids\": [\"35887102\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No experimental structure of the dimer\", \"Computational docking not structurally confirmed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Showed β2 is specifically required for cone survival and cannot be functionally replaced by β1, and linked it to retinoschisin.\",\n      \"evidence\": \"Atp1b2 β1 knock-in mice, IHC, in situ hybridization, cell counting\",\n      \"pmids\": [\"40558505\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of β2–retinoschisin functional coupling not defined\", \"Why cones are more vulnerable than rods unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The identity of the neuronal receptor mediating β2-dependent adhesion and neurite outgrowth, and the direct biochemical mechanisms linking β2 to Merlin/NF2 and retinoschisin, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No neuronal binding partner identified\", \"Direct β2–Merlin interaction not demonstrated\", \"Mechanism of cell-type-specific photoreceptor degeneration unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098631\", \"supporting_discovery_ids\": [3, 9, 2]},\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 9, 13]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-382551\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"R-HSA-1500931\", \"supporting_discovery_ids\": [3, 9]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"complexes\": [\"Na,K-ATPase\"],\n    \"partners\": [\"ATP1A2\", \"ATP1A3\", \"ATP1A1\", \"RS1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}