{"gene":"NECAB3","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":2000,"finding":"XB51 (NECAB3) interacts with the amino-terminal domain of X11L (X11-like protein/APBA2), inhibits the association of X11L with amyloid precursor protein (APP) through a non-competitive mechanism, and abolishes X11L-mediated suppression of beta-amyloid production. The majority of XB51 is localized around the nucleus in a CHAPS buffer-insoluble fraction; association with X11L redistributes XB51 into the CHAPS buffer-soluble fraction.","method":"Yeast two-hybrid screening, co-immunoprecipitation, subcellular fractionation, beta-amyloid ELISA","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal binding confirmed, functional consequence (Abeta production) measured, subcellular redistribution documented, replicated in subsequent study (PMID:12780348)","pmids":["10833507"],"is_preprint":false},{"year":2003,"finding":"Human XB51 (NECAB3) gene produces two isoforms (hXB51alpha, containing exon 9; hXB51beta, lacking exon 9) with opposing effects on Abeta generation. hXB51alpha forms a tripartite complex with X11L and APP, blocking X11L's suppression of Abeta generation (thereby enhancing it). hXB51beta associates with X11L and inhibits its interaction with APP, but suppresses Abeta generation and secretion in an X11L-independent manner.","method":"RT-PCR isoform identification, yeast two-hybrid, co-immunoprecipitation, Abeta secretion assay","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — two orthogonal methods (co-IP and functional Abeta assay), isoform-specific mechanistic dissection, builds on prior work","pmids":["12780348"],"is_preprint":false},{"year":2004,"finding":"NIP1/XB51/NECAB3 is a Golgi-localized protein that physically interacts with the mitotic kinase Nek2 and is phosphorylated by Nek2 in vivo, suggesting a role for Nek2 in Golgi-related cell cycle processes.","method":"Yeast two-hybrid screening, co-immunoprecipitation, in vivo phosphorylation assay, immunofluorescence localization","journal":"Experimental cell research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — physical interaction and in vivo phosphorylation confirmed, Golgi localization by immunostaining, single lab","pmids":["14697346"],"is_preprint":false},{"year":2016,"finding":"NECAB3 binds to the phosphotyrosine-binding (PTB) domain of Mint3, forms a ternary complex with Mint3 and FIH-1 (factor inhibiting HIF-1), and co-localizes with Mint3 at the Golgi apparatus. Through this interaction, NECAB3 promotes HIF-1 activation under normoxia in cancer cells, enhancing glycolysis and tumourigenicity. A dominant-negative NECAB3 mutant that binds Mint3 but lacks an intact monooxygenase domain inhibits HIF-1 activation, implicating the monooxygenase domain in the mechanism.","method":"Yeast two-hybrid screening, co-immunoprecipitation, co-localization by immunofluorescence, shRNA knockdown, dominant-negative mutant expression, HIF-1 target gene expression assay, glycolysis measurement, tumourigenicity assay","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (co-IP, co-localization, domain mutagenesis, KD phenotype, in vivo tumourigenicity), single lab but comprehensive","pmids":["26948053"],"is_preprint":false},{"year":2023,"finding":"Knockdown of NECAB3 in liver cancer cells suppresses migration and invasion, and reduces activation of the HIF-1α/RIT1 signaling pathway. Overexpression of RIT1 rescues the phenotype, placing NECAB3 upstream of RIT1 in this axis.","method":"siRNA knockdown, transwell migration/invasion assay, Western blot for HIF-1α and RIT1, rescue by RIT1 overexpression, in vivo xenograft assay","journal":"Open medicine (Warsaw, Poland)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis by rescue experiment, multiple readouts, single lab","pmids":["37215053"],"is_preprint":false}],"current_model":"NECAB3 (XB51) is a Golgi-localized calcium-binding protein that (1) modulates APP/amyloid-β production by interacting with X11L/APBA2 in an isoform-specific manner, (2) promotes HIF-1 activation under normoxia by forming a ternary complex with Mint3 and FIH-1 at the Golgi through its monooxygenase domain, and (3) is phosphorylated by the Nek2 kinase, linking it to cell cycle-dependent Golgi regulation."},"narrative":{"mechanistic_narrative":"NECAB3 (XB51/NIP1) is a Golgi-associated, calcium-binding adaptor protein that couples scaffold-protein interactions to two distinct biological outputs: amyloid precursor protein (APP) processing and hypoxia-inducible factor (HIF-1) signaling [PMID:10833507, PMID:26948053]. Through its interaction with the X11-like protein X11L (APBA2), NECAB3 modulates amyloid-β generation in an isoform-specific manner: the exon-9-containing hXB51α forms a tripartite complex with X11L and APP that relieves X11L-mediated suppression of Aβ production, whereas hXB51β suppresses Aβ generation through an X11L-independent route [PMID:10833507, PMID:12780348]. In cancer cells, NECAB3 binds the phosphotyrosine-binding domain of Mint3 and assembles a ternary complex with Mint3 and FIH-1 at the Golgi, promoting HIF-1 activation under normoxia and thereby enhancing glycolysis and tumourigenicity; an intact monooxygenase domain is required for this activity [PMID:26948053]. This HIF-1 axis extends to a HIF-1α/RIT1 signaling cascade that drives migration and invasion in liver cancer cells, with NECAB3 acting upstream of RIT1 [PMID:37215053]. NECAB3 is also a physical partner and in vivo substrate of the mitotic kinase Nek2, linking it to cell-cycle-dependent Golgi regulation [PMID:14697346].","teleology":[{"year":2000,"claim":"Established NECAB3's first functional partner and role: it was unknown what regulated X11L's control of amyloid processing, and this work showed XB51 binds X11L's N-terminus and abolishes X11L-mediated suppression of Aβ, defining NECAB3 as a modulator of APP processing.","evidence":"Yeast two-hybrid, co-IP, subcellular fractionation, and Aβ ELISA","pmids":["10833507"],"confidence":"High","gaps":["Mechanism of non-competitive inhibition not structurally resolved","Physiological context of the CHAPS-insoluble perinuclear pool undefined"]},{"year":2003,"claim":"Resolved how a single gene could have opposing effects on Aβ by showing two isoforms diverge: hXB51α (exon 9+) enhances Aβ via a tripartite X11L/APP complex while hXB51β suppresses Aβ X11L-independently, establishing isoform-specific regulation.","evidence":"RT-PCR isoform identification, yeast two-hybrid, co-IP, Aβ secretion assay","pmids":["12780348"],"confidence":"High","gaps":["X11L-independent mechanism of hXB51β not identified","In vivo relevance to amyloid pathology untested"]},{"year":2004,"claim":"Connected NECAB3 to cell-cycle machinery by showing it physically interacts with and is phosphorylated by the mitotic kinase Nek2 at the Golgi, raising a role in Golgi-related cell cycle processes.","evidence":"Yeast two-hybrid, co-IP, in vivo phosphorylation assay, immunofluorescence","pmids":["14697346"],"confidence":"Medium","gaps":["Phosphosite(s) on NECAB3 not mapped","Functional consequence of Nek2 phosphorylation undefined","Single lab, no reciprocal confirmation"]},{"year":2016,"claim":"Defined a distinct signaling function: NECAB3 binds the Mint3 PTB domain and forms a Mint3/FIH-1 ternary complex at the Golgi to drive normoxic HIF-1 activation, glycolysis, and tumourigenicity, with the monooxygenase domain shown necessary by dominant-negative mutagenesis.","evidence":"Yeast two-hybrid, co-IP, co-localization, shRNA knockdown, dominant-negative mutant, HIF-1 target assays, glycolysis and tumourigenicity assays","pmids":["26948053"],"confidence":"High","gaps":["Catalytic activity of the monooxygenase domain not biochemically demonstrated","How the complex inhibits FIH-1 mechanistically unresolved"]},{"year":2023,"claim":"Extended the HIF-1 axis to a defined downstream effector by placing NECAB3 upstream of RIT1 via HIF-1α, with RIT1 overexpression rescuing migration/invasion defects of NECAB3 knockdown in liver cancer.","evidence":"siRNA knockdown, transwell migration/invasion, Western blot, RIT1 rescue, xenograft assay","pmids":["37215053"],"confidence":"Medium","gaps":["Direct molecular link from HIF-1α to RIT1 not established","Single lab, limited to liver cancer context"]},{"year":null,"claim":"How NECAB3's calcium-binding and monooxygenase domains mechanistically contribute to its adaptor functions, and whether its APP-modulating and HIF-1-promoting roles are coordinated, remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of any NECAB3 complex","Catalytic function of the monooxygenase domain undemonstrated","Calcium-binding contribution to function untested"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1,3]}],"localization":[{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[2,3]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[3,4]}],"complexes":[],"partners":["APBA2","NEK2","APBA3","FIH1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96P71","full_name":"N-terminal EF-hand calcium-binding protein 3","aliases":["Amyloid-beta A4 protein-binding family A member 2-binding protein","Nek2-interacting protein 1","Neuronal calcium-binding protein 3","X11L-binding protein 51"],"length_aa":396,"mass_kda":44.4,"function":"Inhibits the interaction of APBA2 with amyloid-beta precursor protein (APP), and hence allows formation of amyloid-beta. May enhance the activity of HIF1A and thus promote glycolysis under normoxic conditions; the function requires its ABM domain and may implicate the stabilization of the interaction between HIF1AN and APBA3","subcellular_location":"Golgi apparatus","url":"https://www.uniprot.org/uniprotkb/Q96P71/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/NECAB3","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/NECAB3","total_profiled":1310},"omim":[{"mim_id":"621427","title":"N-TERMINAL EF-HAND CALCIUM-BINDING PROTEIN 1; NECAB1","url":"https://www.omim.org/entry/621427"},{"mim_id":"618130","title":"N-TERMINAL EF-HAND CALCIUM-BINDING PROTEIN 2; NECAB2","url":"https://www.omim.org/entry/618130"},{"mim_id":"612478","title":"N-TERMINAL EF-HAND CALCIUM-BINDING PROTEIN 3; NECAB3","url":"https://www.omim.org/entry/612478"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Golgi apparatus","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/NECAB3"},"hgnc":{"alias_symbol":["XB51","dJ63M2.4","NIP1","dJ63M2.5","EFCBP3"],"prev_symbol":["SYTIP2","APBA2BP"]},"alphafold":{"accession":"Q96P71","domains":[{"cath_id":"1.10.238.10","chopping":"39-134","consensus_level":"high","plddt":82.9231,"start":39,"end":134},{"cath_id":"3.30.70.100","chopping":"295-391","consensus_level":"high","plddt":93.8843,"start":295,"end":391}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96P71","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96P71-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96P71-F1-predicted_aligned_error_v6.png","plddt_mean":70.81},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=NECAB3","jax_strain_url":"https://www.jax.org/strain/search?query=NECAB3"},"sequence":{"accession":"Q96P71","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96P71.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96P71/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96P71"}},"corpus_meta":[{"pmid":"31267263","id":"PMC_31267263","title":"GNAS-AS1/miR-4319/NECAB3 axis promotes migration and invasion of non-small cell lung cancer cells by altering macrophage polarization.","date":"2019","source":"Functional & integrative genomics","url":"https://pubmed.ncbi.nlm.nih.gov/31267263","citation_count":75,"is_preprint":false},{"pmid":"22082871","id":"PMC_22082871","title":"Expression pattern and functions of autophagy-related gene atg5 in zebrafish organogenesis.","date":"2011","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/22082871","citation_count":54,"is_preprint":false},{"pmid":"10833507","id":"PMC_10833507","title":"Regulation of X11L-dependent amyloid precursor protein metabolism by XB51, a novel X11L-binding protein.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10833507","citation_count":37,"is_preprint":false},{"pmid":"26948053","id":"PMC_26948053","title":"NECAB3 Promotes Activation of Hypoxia-inducible factor-1 during Normoxia and Enhances Tumourigenicity of Cancer Cells.","date":"2016","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/26948053","citation_count":30,"is_preprint":false},{"pmid":"33823999","id":"PMC_33823999","title":"Conception by fertility treatment and offspring deoxyribonucleic acid methylation.","date":"2021","source":"Fertility and sterility","url":"https://pubmed.ncbi.nlm.nih.gov/33823999","citation_count":29,"is_preprint":false},{"pmid":"12780348","id":"PMC_12780348","title":"XB51 isoforms mediate Alzheimer's beta-amyloid peptide production by X11L (X11-like protein)-dependent and -independent mechanisms.","date":"2003","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/12780348","citation_count":20,"is_preprint":false},{"pmid":"34556649","id":"PMC_34556649","title":"Analyses of child cardiometabolic phenotype following assisted reproductive technologies using a pragmatic trial emulation approach.","date":"2021","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/34556649","citation_count":18,"is_preprint":false},{"pmid":"14697346","id":"PMC_14697346","title":"NIP1/XB51/NECAB3 is a potential substrate of Nek2, suggesting specific roles of Nek2 in Golgi.","date":"2004","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/14697346","citation_count":15,"is_preprint":false},{"pmid":"19035353","id":"PMC_19035353","title":"Isolation and expression analysis of Alzheimer's disease-related gene xb51 in zebrafish.","date":"2008","source":"Developmental dynamics : an official publication of the American Association of Anatomists","url":"https://pubmed.ncbi.nlm.nih.gov/19035353","citation_count":10,"is_preprint":false},{"pmid":"17364817","id":"PMC_17364817","title":"EFCBP1/NECAB1, a brain-specifically expressed gene with highest abundance in temporal lobe, encodes a protein containing EF-hand and antibiotic biosynthesis monooxygenase domains.","date":"2007","source":"DNA sequence : the journal of DNA sequencing and mapping","url":"https://pubmed.ncbi.nlm.nih.gov/17364817","citation_count":10,"is_preprint":false},{"pmid":"40121529","id":"PMC_40121529","title":"AAT-MSC-EVs: Novel implications for suppressing ferroptosis, fibrosis and pain associated with chronic pancreatitis.","date":"2025","source":"Molecular therapy : the journal of the American Society of Gene Therapy","url":"https://pubmed.ncbi.nlm.nih.gov/40121529","citation_count":5,"is_preprint":false},{"pmid":"37215053","id":"PMC_37215053","title":"NECAB3 promotes the migration and invasion of liver cancer cells through HIF-1α/RIT1 signaling pathway.","date":"2023","source":"Open medicine (Warsaw, Poland)","url":"https://pubmed.ncbi.nlm.nih.gov/37215053","citation_count":4,"is_preprint":false},{"pmid":"39296922","id":"PMC_39296922","title":"NECAB1-3, parvalbumin, calbindin, and calretinin in the hippocampus of the European mole.","date":"2024","source":"Frontiers in neuroanatomy","url":"https://pubmed.ncbi.nlm.nih.gov/39296922","citation_count":4,"is_preprint":false},{"pmid":"38934399","id":"PMC_38934399","title":"NECAB family of neuronal calcium-binding proteins in health and disease.","date":"2024","source":"Neural regeneration research","url":"https://pubmed.ncbi.nlm.nih.gov/38934399","citation_count":2,"is_preprint":false},{"pmid":"23017458","id":"PMC_23017458","title":"[Toxic effects of trimethadione on zebrafish early development].","date":"2012","source":"Yi chuan = Hereditas","url":"https://pubmed.ncbi.nlm.nih.gov/23017458","citation_count":1,"is_preprint":false},{"pmid":"39358554","id":"PMC_39358554","title":"Sex differences in DNA methylation variations according to ART conception-evidence from the Norwegian mother, father, and child cohort study.","date":"2024","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/39358554","citation_count":1,"is_preprint":false},{"pmid":"42106700","id":"PMC_42106700","title":"Association between air pollution exposure and increased chronic kidney disease risk: the modifying effects of genetic susceptibility, transcriptomic, and proteomic signatures.","date":"2026","source":"BMC medicine","url":"https://pubmed.ncbi.nlm.nih.gov/42106700","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":10407,"output_tokens":1481,"usd":0.026718,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8180,"output_tokens":2202,"usd":0.047975,"stage2_stop_reason":"end_turn"},"total_usd":0.074693,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2000,\n      \"finding\": \"XB51 (NECAB3) interacts with the amino-terminal domain of X11L (X11-like protein/APBA2), inhibits the association of X11L with amyloid precursor protein (APP) through a non-competitive mechanism, and abolishes X11L-mediated suppression of beta-amyloid production. The majority of XB51 is localized around the nucleus in a CHAPS buffer-insoluble fraction; association with X11L redistributes XB51 into the CHAPS buffer-soluble fraction.\",\n      \"method\": \"Yeast two-hybrid screening, co-immunoprecipitation, subcellular fractionation, beta-amyloid ELISA\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal binding confirmed, functional consequence (Abeta production) measured, subcellular redistribution documented, replicated in subsequent study (PMID:12780348)\",\n      \"pmids\": [\"10833507\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Human XB51 (NECAB3) gene produces two isoforms (hXB51alpha, containing exon 9; hXB51beta, lacking exon 9) with opposing effects on Abeta generation. hXB51alpha forms a tripartite complex with X11L and APP, blocking X11L's suppression of Abeta generation (thereby enhancing it). hXB51beta associates with X11L and inhibits its interaction with APP, but suppresses Abeta generation and secretion in an X11L-independent manner.\",\n      \"method\": \"RT-PCR isoform identification, yeast two-hybrid, co-immunoprecipitation, Abeta secretion assay\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — two orthogonal methods (co-IP and functional Abeta assay), isoform-specific mechanistic dissection, builds on prior work\",\n      \"pmids\": [\"12780348\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"NIP1/XB51/NECAB3 is a Golgi-localized protein that physically interacts with the mitotic kinase Nek2 and is phosphorylated by Nek2 in vivo, suggesting a role for Nek2 in Golgi-related cell cycle processes.\",\n      \"method\": \"Yeast two-hybrid screening, co-immunoprecipitation, in vivo phosphorylation assay, immunofluorescence localization\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — physical interaction and in vivo phosphorylation confirmed, Golgi localization by immunostaining, single lab\",\n      \"pmids\": [\"14697346\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"NECAB3 binds to the phosphotyrosine-binding (PTB) domain of Mint3, forms a ternary complex with Mint3 and FIH-1 (factor inhibiting HIF-1), and co-localizes with Mint3 at the Golgi apparatus. Through this interaction, NECAB3 promotes HIF-1 activation under normoxia in cancer cells, enhancing glycolysis and tumourigenicity. A dominant-negative NECAB3 mutant that binds Mint3 but lacks an intact monooxygenase domain inhibits HIF-1 activation, implicating the monooxygenase domain in the mechanism.\",\n      \"method\": \"Yeast two-hybrid screening, co-immunoprecipitation, co-localization by immunofluorescence, shRNA knockdown, dominant-negative mutant expression, HIF-1 target gene expression assay, glycolysis measurement, tumourigenicity assay\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (co-IP, co-localization, domain mutagenesis, KD phenotype, in vivo tumourigenicity), single lab but comprehensive\",\n      \"pmids\": [\"26948053\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Knockdown of NECAB3 in liver cancer cells suppresses migration and invasion, and reduces activation of the HIF-1α/RIT1 signaling pathway. Overexpression of RIT1 rescues the phenotype, placing NECAB3 upstream of RIT1 in this axis.\",\n      \"method\": \"siRNA knockdown, transwell migration/invasion assay, Western blot for HIF-1α and RIT1, rescue by RIT1 overexpression, in vivo xenograft assay\",\n      \"journal\": \"Open medicine (Warsaw, Poland)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis by rescue experiment, multiple readouts, single lab\",\n      \"pmids\": [\"37215053\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"NECAB3 (XB51) is a Golgi-localized calcium-binding protein that (1) modulates APP/amyloid-β production by interacting with X11L/APBA2 in an isoform-specific manner, (2) promotes HIF-1 activation under normoxia by forming a ternary complex with Mint3 and FIH-1 at the Golgi through its monooxygenase domain, and (3) is phosphorylated by the Nek2 kinase, linking it to cell cycle-dependent Golgi regulation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"NECAB3 (XB51/NIP1) is a Golgi-associated, calcium-binding adaptor protein that couples scaffold-protein interactions to two distinct biological outputs: amyloid precursor protein (APP) processing and hypoxia-inducible factor (HIF-1) signaling [#0, #3]. Through its interaction with the X11-like protein X11L (APBA2), NECAB3 modulates amyloid-β generation in an isoform-specific manner: the exon-9-containing hXB51α forms a tripartite complex with X11L and APP that relieves X11L-mediated suppression of Aβ production, whereas hXB51β suppresses Aβ generation through an X11L-independent route [#0, #1]. In cancer cells, NECAB3 binds the phosphotyrosine-binding domain of Mint3 and assembles a ternary complex with Mint3 and FIH-1 at the Golgi, promoting HIF-1 activation under normoxia and thereby enhancing glycolysis and tumourigenicity; an intact monooxygenase domain is required for this activity [#3]. This HIF-1 axis extends to a HIF-1α/RIT1 signaling cascade that drives migration and invasion in liver cancer cells, with NECAB3 acting upstream of RIT1 [#4]. NECAB3 is also a physical partner and in vivo substrate of the mitotic kinase Nek2, linking it to cell-cycle-dependent Golgi regulation [#2].\",\n  \"teleology\": [\n    {\n      \"year\": 2000,\n      \"claim\": \"Established NECAB3's first functional partner and role: it was unknown what regulated X11L's control of amyloid processing, and this work showed XB51 binds X11L's N-terminus and abolishes X11L-mediated suppression of Aβ, defining NECAB3 as a modulator of APP processing.\",\n      \"evidence\": \"Yeast two-hybrid, co-IP, subcellular fractionation, and Aβ ELISA\",\n      \"pmids\": [\"10833507\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of non-competitive inhibition not structurally resolved\", \"Physiological context of the CHAPS-insoluble perinuclear pool undefined\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Resolved how a single gene could have opposing effects on Aβ by showing two isoforms diverge: hXB51α (exon 9+) enhances Aβ via a tripartite X11L/APP complex while hXB51β suppresses Aβ X11L-independently, establishing isoform-specific regulation.\",\n      \"evidence\": \"RT-PCR isoform identification, yeast two-hybrid, co-IP, Aβ secretion assay\",\n      \"pmids\": [\"12780348\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"X11L-independent mechanism of hXB51β not identified\", \"In vivo relevance to amyloid pathology untested\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Connected NECAB3 to cell-cycle machinery by showing it physically interacts with and is phosphorylated by the mitotic kinase Nek2 at the Golgi, raising a role in Golgi-related cell cycle processes.\",\n      \"evidence\": \"Yeast two-hybrid, co-IP, in vivo phosphorylation assay, immunofluorescence\",\n      \"pmids\": [\"14697346\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Phosphosite(s) on NECAB3 not mapped\", \"Functional consequence of Nek2 phosphorylation undefined\", \"Single lab, no reciprocal confirmation\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Defined a distinct signaling function: NECAB3 binds the Mint3 PTB domain and forms a Mint3/FIH-1 ternary complex at the Golgi to drive normoxic HIF-1 activation, glycolysis, and tumourigenicity, with the monooxygenase domain shown necessary by dominant-negative mutagenesis.\",\n      \"evidence\": \"Yeast two-hybrid, co-IP, co-localization, shRNA knockdown, dominant-negative mutant, HIF-1 target assays, glycolysis and tumourigenicity assays\",\n      \"pmids\": [\"26948053\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Catalytic activity of the monooxygenase domain not biochemically demonstrated\", \"How the complex inhibits FIH-1 mechanistically unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Extended the HIF-1 axis to a defined downstream effector by placing NECAB3 upstream of RIT1 via HIF-1α, with RIT1 overexpression rescuing migration/invasion defects of NECAB3 knockdown in liver cancer.\",\n      \"evidence\": \"siRNA knockdown, transwell migration/invasion, Western blot, RIT1 rescue, xenograft assay\",\n      \"pmids\": [\"37215053\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular link from HIF-1α to RIT1 not established\", \"Single lab, limited to liver cancer context\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How NECAB3's calcium-binding and monooxygenase domains mechanistically contribute to its adaptor functions, and whether its APP-modulating and HIF-1-promoting roles are coordinated, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of any NECAB3 complex\", \"Catalytic function of the monooxygenase domain undemonstrated\", \"Calcium-binding contribution to function untested\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [2, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [3, 4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"APBA2\", \"Nek2\", \"APBA3\", \"FIH1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}