{"gene":"FBXL14","run_date":"2026-06-09T23:54:43","timeline":{"discoveries":[{"year":2009,"finding":"FBXL14 (an F-box E3 ubiquitin ligase) directly interacts with SNAIL1 and promotes its polyubiquitylation and proteasome degradation independently of GSK-3β-mediated phosphorylation. shRNA-mediated inhibition of FBXL14 stabilizes both ectopically expressed and endogenous SNAIL1 in vivo. FBXL14 expression is down-regulated during hypoxia, which stabilizes SNAIL1.","method":"Co-immunoprecipitation, ubiquitylation assay, shRNA knockdown, proteasome inhibitor assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP and ubiquitination assays with shRNA KD rescue, replicated across multiple cell lines and conditions in a focused mechanistic study","pmids":["19955572"],"is_preprint":false},{"year":2016,"finding":"FBXL14 ubiquitinates c-Myc to promote its degradation in glioblastoma stem cells (GSCs). The deubiquitinase USP13 antagonizes FBXL14-mediated c-Myc ubiquitination, stabilizing c-Myc and maintaining GSC self-renewal. Overexpression of FBXL14 induces c-Myc degradation, promotes GSC differentiation, and inhibits tumor growth; the ubiquitin-insensitive T58A-c-Myc mutant rescues FBXL14 overexpression effects.","method":"Overexpression/knockdown, ubiquitination assay, rescue with ubiquitin-insensitive c-Myc mutant (T58A), tumor growth assays","journal":"The Journal of experimental medicine","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods including mutagenesis rescue, KD/OE with defined cellular phenotypes, and in vivo tumor assays in a single focused study","pmids":["27923907"],"is_preprint":false},{"year":2013,"finding":"FBXL14 (referred to as Ppa/FBXL14) acts as a cytoplasmic ubiquitin ligase targeting SNAIL1. In the same study, FBXL5 was identified as a distinct nuclear ubiquitin ligase for SNAIL1, distinguishing the subcellular compartment of FBXL14-mediated versus FBXL5-mediated Snail1 degradation.","method":"shRNA screening, Co-immunoprecipitation, ubiquitination assay, subcellular fractionation","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and ubiquitination assays in a single lab, contextualizes FBXL14's cytoplasmic localization for Snail1 degradation","pmids":["24157836"],"is_preprint":false},{"year":2013,"finding":"FBXL14 promotes proteasomal degradation of the EMT transcription factor Twist1. β-TRCP was additionally identified as a separate E3 ligase for Twist1, whose degradation requires IKKβ-mediated phosphorylation, distinguishing a phosphorylation-independent (FBXL14) from a phosphorylation-dependent (β-TRCP) mechanism.","method":"Protein stability assay, knockdown/overexpression, ubiquitination assay","journal":"Discovery medicine","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, indirect evidence for FBXL14-Twist1 relationship referenced as prior finding; β-TRCP mechanism directly demonstrated","pmids":["23375009"],"is_preprint":false},{"year":2015,"finding":"FBXL14 promotes polyubiquitination and proteasomal degradation of the EMT transcription factor Twist1. The compound Imipramine Blue (IB) suppresses Twist1-driven EMT in head and neck squamous cell carcinoma by enhancing FBXL14-mediated Twist1 polyubiquitination.","method":"Ubiquitination assay, co-immunoprecipitation, protein stability/degradation assay, shRNA knockdown","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ubiquitination assays and Co-IP in a single lab with pharmacological modulation, but limited mechanistic dissection of FBXL14-Twist1 interaction details","pmids":["26257063"],"is_preprint":false},{"year":2017,"finding":"The SCF-FBXL14 complex ubiquitinates HES1 (hairy and enhancer of split 1) and promotes its proteasomal degradation. FBXL14 directly associates with HES1, and a conserved WRPW motif at the C-terminus of HES1 is essential for HES1 binding to FBXL14 and for ubiquitin-dependent HES1 degradation. SCF-FBXL14-mediated HES1 proteolysis stimulates neuronal differentiation.","method":"siRNA knockdown, co-immunoprecipitation, ubiquitination assay, HES1 half-life measurement, WRPW motif mutagenesis, neuronal differentiation assay in mES and F9 cells","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — Co-IP, ubiquitination assay, active-motif mutagenesis, and functional differentiation readout in a single focused study with multiple orthogonal methods","pmids":["29070679"],"is_preprint":false},{"year":2018,"finding":"FBXL14 directly interacts with CDCP1 (CUB-domain-containing protein 1) and facilitates its ubiquitination and proteasomal degradation in triple-negative breast cancer cells, thereby suppressing breast cancer metastasis. miR-17/20a were shown to negatively control FBXL14 E3 ligase levels upstream.","method":"Co-immunoprecipitation, ubiquitination assay, protein stability assay, overexpression/knockdown","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and ubiquitination assays with functional metastasis readout, single lab","pmids":["29973690"],"is_preprint":false},{"year":2018,"finding":"LKB1 boosts the interaction between Snail1 and FBXL14, leading to increased ubiquitin-mediated Snail1 degradation. Metformin increases Snail1 ubiquitination via augmenting LKB1 cytoplasmic localization, placing LKB1 upstream of FBXL14-mediated Snail1 degradation.","method":"Co-immunoprecipitation, ubiquitination assay, subcellular fractionation, overexpression/knockdown","journal":"Cancer science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and ubiquitination assays with pharmacological and genetic modulation in a single lab","pmids":["29601127"],"is_preprint":false},{"year":2019,"finding":"BRD4, an acetylation reader, binds acetylated lysines K146 and K187 on Snail in an acetylation-dependent manner, thereby preventing Snail recognition by the E3 ubiquitin ligases FBXL14 and β-TrCP1, and inhibiting Snail polyubiquitination and proteasomal degradation.","method":"Co-immunoprecipitation, ubiquitination assay, acetylation site mutagenesis, protein stability assay","journal":"Cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with mutagenesis in a single lab; FBXL14's role is indirectly demonstrated through competition with BRD4 for Snail binding","pmids":["31311807"],"is_preprint":false},{"year":2020,"finding":"CLK3 phosphorylates USP13 at Y708, which promotes USP13 binding to c-Myc and prevents FBXL14-mediated c-Myc ubiquitination, thereby activating purine metabolic gene transcription in cholangiocarcinoma. This places CLK3 upstream of the USP13/FBXL14 axis regulating c-Myc stability.","method":"In vitro kinase assay, co-immunoprecipitation, ubiquitination assay, phospho-site mutagenesis, metabolic profiling","journal":"The Journal of experimental medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — kinase assay and Co-IP with mutagenesis, single lab; FBXL14's role is part of the described pathway","pmids":["32453420"],"is_preprint":false},{"year":2021,"finding":"IGFBP-3 directly binds vimentin and promotes vimentin's association with the E3 ligase FBXL14, causing vimentin proteasomal degradation. The C-terminal domain of IGFBP-3 and the head domain of vimentin are essential for their interaction.","method":"Co-immunoprecipitation, protein stability/degradation assay, domain-mapping with truncation mutants, in vitro and in vivo metastasis assays","journal":"Cancers","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with domain mapping and functional metastasis readout, single lab","pmids":["33801272"],"is_preprint":false},{"year":2022,"finding":"FBXL14 (as the SCF-FBXL14 E3 ligase) binds RPA194 (the catalytic subunit of RNA Polymerase I) and mediates RPA194 ubiquitination and degradation in cancer cells treated with the Pol I inhibitor BMH-21. Mutation analysis in yeast identified lysines K1150, K1153, and K1156 on Rpa190 as relevant for protein degradation.","method":"RNAi screen, co-immunoprecipitation, ubiquitination assay, lysine-to-arginine mutagenesis in yeast, protein stability assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — RNAi screen followed by Co-IP, ubiquitination assay, and active-site mutagenesis with functional degradation readout in a single focused study","pmids":["36372232"],"is_preprint":false},{"year":2023,"finding":"USP13 stabilizes Twist1 by specifically cleaving the K48-linked polyubiquitin chains of Twist1 induced by FBXL14. USP13 directly interacts with Twist1, and this axis promotes breast cancer cell migration and invasion. Additionally, Twist1 can inhibit USP13 transcriptional activity, forming a negative feedback loop.","method":"Co-immunoprecipitation, GST-pulldown, ubiquitination assay, Western blot, chromatin immunoprecipitation, luciferase reporter assay, migration/invasion assays, mouse lung metastasis assay","journal":"Cellular oncology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP and GST-pulldown confirming direct interaction, K48 linkage-specific ubiquitination assay, multiple orthogonal functional readouts","pmids":["36732432"],"is_preprint":false},{"year":2023,"finding":"NIPSNAP1 sequesters FBXL14 to prevent FBXL14-mediated c-Myc ubiquitination and proteasomal turnover, thereby maintaining c-Myc levels in cancer cells and inhibiting P27-dependent senescence. c-Myc-Miz1 transcriptionally represses NIPSNAP1, establishing a feedback loop.","method":"Co-immunoprecipitation (NIPSNAP1-FBXL14 interaction), proteasome degradation assay, luciferase reporter assay, siRNA knockdown, xenograft model","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP demonstrating NIPSNAP1-FBXL14 complex with functional ubiquitination/degradation readout, single lab","pmids":["37340421"],"is_preprint":false},{"year":2025,"finding":"β-Hydroxybutyrylation (Kbhb) of Snail at lysine K152 (mediated by CBP) stabilizes Snail by blocking recognition by FBXL14, preventing FBXL14-mediated Snail degradation and promoting cancer metastasis.","method":"Ubiquitination assay, co-immunoprecipitation, site-specific mutagenesis (K152), CBP inhibitor experiments, in vivo metastasis assays","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis and ubiquitination assay with pharmacological intervention, single lab; indirect demonstration of FBXL14 blockade","pmids":["40675949"],"is_preprint":false},{"year":2025,"finding":"FBXL14 ubiquitinates DUSP6, promoting its degradation and thereby activating the NRF2 signaling pathway in macrophages, which inhibits foam cell formation and atherosclerotic inflammation.","method":"siRNA knockdown, overexpression, immunoprecipitation for ubiquitination, Western blot, bioinformatics-guided E3 ligase identification, in vivo ApoE-/- mouse model","journal":"Journal of receptor and signal transduction research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP ubiquitination assay with KD/OE and in vivo model, single lab, bioinformatics-guided candidate","pmids":["40051291"],"is_preprint":false},{"year":2023,"finding":"siRNA-mediated depletion of FBXL14 in neonatal rat cardiomyocytes results in decreased cell size under basal conditions, implicating FBXL14 as a positive regulator of cardiomyocyte hypertrophy.","method":"siRNA knockdown, automated microscopy cell size measurement, 3H-isoleucine incorporation assay","journal":"Frontiers in physiology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single functional screen with cell size readout only, no molecular substrate or pathway identified for FBXL14's role in this context","pmids":["36969608"],"is_preprint":false}],"current_model":"FBXL14 is the substrate-recognition subunit of an SCF-type E3 ubiquitin ligase complex that targets multiple short-lived proteins—including SNAIL1, Twist1, c-Myc, HES1, RPA194, CDCP1, vimentin, and DUSP6—for K48-linked polyubiquitination and proteasomal degradation, with its activity regulated by competing deubiquitinases (USP13), upstream kinases (LKB1, CLK3/USP13 axis), sequestering proteins (NIPSNAP1), and post-translational modifications on substrates (acetylation by BRD4, β-hydroxybutyrylation) that block substrate recognition, placing FBXL14 as a central post-translational regulator of EMT, stem cell maintenance, neuronal differentiation, ribosome biogenesis stress responses, and metabolic signaling."},"narrative":{"mechanistic_narrative":"FBXL14 is the substrate-recognition subunit of an SCF-type E3 ubiquitin ligase that targets multiple short-lived regulatory proteins for polyubiquitination and proteasomal degradation, positioning it as a post-translational gatekeeper of epithelial-mesenchymal transition (EMT), stem-cell maintenance, and differentiation [PMID:19955572, PMID:27923907, PMID:29070679]. It directly binds and ubiquitinates the EMT transcription factor SNAIL1 in the cytoplasm, doing so independently of GSK-3β phosphorylation, and its downregulation under hypoxia stabilizes SNAIL1 [PMID:19955572, PMID:24157836]. Beyond SNAIL1, FBXL14 degrades a broad substrate set including Twist1 [PMID:26257063], c-Myc [PMID:27923907], HES1 via the substrate's C-terminal WRPW motif, thereby driving neuronal differentiation [PMID:29070679], the RNA Polymerase I catalytic subunit RPA194 during Pol I inhibition stress [PMID:36372232], CDCP1 to suppress breast cancer metastasis [PMID:29973690], vimentin [PMID:33801272], and DUSP6 to activate NRF2 signaling in macrophages [PMID:40051291]. FBXL14 activity is constrained at several levels: the deubiquitinase USP13 reverses FBXL14-imposed K48-linked chains on c-Myc and Twist1 [PMID:27923907, PMID:36732432], NIPSNAP1 sequesters FBXL14 away from c-Myc [PMID:37340421], LKB1 promotes the SNAIL1–FBXL14 interaction [PMID:29601127], and substrate post-translational modifications—BRD4-read acetylation and CBP-mediated β-hydroxybutyrylation of SNAIL—block FBXL14 recognition [PMID:31311807, PMID:40675949].","teleology":[{"year":2009,"claim":"Established FBXL14 as a bona fide E3 ligase by showing it directly degrades SNAIL1 through a phosphorylation-independent route, defining a parallel arm of EMT control distinct from GSK-3β-dependent turnover.","evidence":"Co-IP, ubiquitination assay, and shRNA knockdown rescue across cell lines, with hypoxia-dependent downregulation","pmids":["19955572"],"confidence":"High","gaps":["Did not define the F-box/SCF complex composition","Mechanism of FBXL14 downregulation under hypoxia not resolved"]},{"year":2013,"claim":"Resolved where FBXL14 acts and broadened its substrate range, localizing FBXL14-mediated SNAIL1 degradation to the cytoplasm (distinct from nuclear FBXL5) and implicating Twist1 as an additional EMT-factor substrate.","evidence":"shRNA screening, subcellular fractionation, Co-IP and ubiquitination assays; Twist1 stability assays distinguishing phosphorylation-independent from β-TRCP-dependent degradation","pmids":["24157836","23375009"],"confidence":"Medium","gaps":["FBXL14-Twist1 interaction interface not mapped in these studies","Single-lab evidence for compartmentalization"]},{"year":2016,"claim":"Connected FBXL14 to oncogenic c-Myc turnover and stem-cell fate, showing it degrades c-Myc to promote glioblastoma stem-cell differentiation, with USP13 acting as the opposing deubiquitinase.","evidence":"Overexpression/knockdown, ubiquitination assay, rescue with ubiquitin-insensitive T58A-c-Myc, and tumor growth assays","pmids":["27923907"],"confidence":"High","gaps":["Whether c-Myc recognition requires a specific degron not defined","Direct competition kinetics between FBXL14 and USP13 not quantified"]},{"year":2017,"claim":"Defined the substrate degron for one FBXL14 target, demonstrating that the conserved C-terminal WRPW motif of HES1 is required for binding and degradation, linking SCF-FBXL14 proteolysis to neuronal differentiation.","evidence":"siRNA knockdown, Co-IP, ubiquitination assay, HES1 half-life measurement, WRPW motif mutagenesis, and neuronal differentiation assays in mES and F9 cells","pmids":["29070679"],"confidence":"High","gaps":["Whether other substrates use analogous motifs unknown","Structural basis of WRPW-FBXL14 recognition not solved"]},{"year":2018,"claim":"Extended FBXL14 substrate scope to CDCP1 and identified upstream regulatory inputs, with miR-17/20a controlling FBXL14 levels and LKB1 enhancing SNAIL1-FBXL14 association.","evidence":"Co-IP, ubiquitination and protein stability assays, knockdown/overexpression, subcellular fractionation, and metformin/LKB1 modulation","pmids":["29973690","29601127"],"confidence":"Medium","gaps":["How LKB1 mechanistically promotes the SNAIL1-FBXL14 interaction unclear","miR-17/20a regulation of FBXL14 is correlative at the level shown"]},{"year":2019,"claim":"Showed that substrate post-translational modification gates FBXL14 access, as BRD4 binding to acetylated SNAIL lysines blocks recognition by FBXL14 (and β-TrCP1), preventing degradation.","evidence":"Co-IP, ubiquitination assay, acetylation-site mutagenesis, and protein stability assays","pmids":["31311807"],"confidence":"Medium","gaps":["FBXL14's role inferred from competition rather than directly assayed","Single-lab evidence"]},{"year":2020,"claim":"Placed a kinase upstream of the FBXL14-opposing deubiquitinase, showing CLK3 phosphorylates USP13 to enhance its c-Myc binding and shield c-Myc from FBXL14, coupling the axis to purine metabolism.","evidence":"In vitro kinase assay, Co-IP, ubiquitination assay, phospho-site mutagenesis, and metabolic profiling in cholangiocarcinoma","pmids":["32453420"],"confidence":"Medium","gaps":["FBXL14 activity not directly measured, inferred via USP13 antagonism","Single-lab pathway model"]},{"year":2021,"claim":"Identified a scaffolding mechanism for substrate delivery, with IGFBP-3 bridging vimentin to FBXL14 to drive vimentin degradation and suppress metastasis.","evidence":"Co-IP, protein stability assays, domain mapping with truncation mutants, and in vitro/in vivo metastasis assays","pmids":["33801272"],"confidence":"Medium","gaps":["Whether IGFBP-3 is generally required for vimentin recognition unknown","Single-lab evidence"]},{"year":2022,"claim":"Revealed an unanticipated role in ribosome biogenesis stress, showing SCF-FBXL14 ubiquitinates and degrades the Pol I catalytic subunit RPA194 upon Pol I inhibition, with conserved lysines mapped in yeast.","evidence":"RNAi screen, Co-IP, ubiquitination assay, lysine-to-arginine mutagenesis in yeast, and protein stability assays","pmids":["36372232"],"confidence":"High","gaps":["Trigger linking Pol I inhibition to FBXL14 engagement not defined","Physiological context beyond drug-induced stress unclear"]},{"year":2023,"claim":"Detailed reversal and sequestration controls on FBXL14, with USP13 cleaving FBXL14-imposed K48 chains on Twist1 and NIPSNAP1 sequestering FBXL14 to spare c-Myc, each embedded in feedback loops; also implicated FBXL14 in cardiomyocyte hypertrophy.","evidence":"Co-IP, GST-pulldown, K48 linkage-specific ubiquitination, ChIP, migration/invasion and metastasis assays; separately, siRNA knockdown with cell-size and 3H-isoleucine incorporation in cardiomyocytes","pmids":["36732432","37340421","36969608"],"confidence":"High","gaps":["NIPSNAP1 sequestration mechanism shown by Co-IP in a single lab","Cardiomyocyte phenotype lacks an identified molecular substrate"]},{"year":2025,"claim":"Expanded the modification-based evasion paradigm and extended FBXL14 into metabolic/inflammatory signaling, showing CBP-mediated β-hydroxybutyrylation of SNAIL K152 blocks FBXL14 recognition, and that FBXL14 degrades DUSP6 to activate NRF2 in macrophages.","evidence":"Site-specific mutagenesis, ubiquitination assays, CBP inhibitor experiments, and in vivo metastasis and ApoE-/- atherosclerosis models","pmids":["40675949","40051291"],"confidence":"Medium","gaps":["DUSP6 degradation evidence is bioinformatics-guided and single-lab","Whether multiple acyl modifications converge on the same SNAIL degron unclear"]},{"year":null,"claim":"The structural basis by which FBXL14's leucine-rich repeats recognize its diverse substrate degrons, and the composition/regulation of the assembled SCF-FBXL14 holoenzyme, remain undefined across the corpus.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of FBXL14-substrate complexes","Unifying degron logic across SNAIL1, Twist1, c-Myc, HES1, RPA194, CDCP1, vimentin, DUSP6 unknown","In vivo loss-of-function phenotype of FBXL14 not established genetically"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1,5,11]},{"term_id":"GO:0016874","term_label":"ligase activity","supporting_discovery_ids":[0,5,11]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,12,13]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[2,7]}],"pathway":[{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,1,5,11]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[5]}],"complexes":["SCF (SKP1-CUL1-F-box) E3 ubiquitin ligase"],"partners":["SNAI1","TWIST1","MYC","HES1","RPA194","USP13","NIPSNAP1","CDCP1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8N1E6","full_name":"F-box/LRR-repeat protein 14","aliases":["F-box and leucine-rich repeat protein 14"],"length_aa":418,"mass_kda":45.9,"function":"Substrate-recognition component of some SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin-protein ligase complexes. The SCF(FBXL14) complex acts by mediating ubiquitination and subsequent degradation of SNAI1","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q8N1E6/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/FBXL14","classification":"Not Classified","n_dependent_lines":21,"n_total_lines":1208,"dependency_fraction":0.0173841059602649},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/FBXL14","total_profiled":1310},"omim":[{"mim_id":"609081","title":"F-BOX AND LEUCINE-RICH REPEAT PROTEIN 14; FBXL14","url":"https://www.omim.org/entry/609081"},{"mim_id":"604238","title":"SNAIL FAMILY TRANSCRIPTIONAL REPRESSOR 1; SNAI1","url":"https://www.omim.org/entry/604238"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/FBXL14"},"hgnc":{"alias_symbol":["MGC40195","Fbl14"],"prev_symbol":[]},"alphafold":{"accession":"Q8N1E6","domains":[{"cath_id":"1.20.1280.50","chopping":"1-46","consensus_level":"medium","plddt":89.0026,"start":1,"end":46},{"cath_id":"3.80.10.10","chopping":"55-234","consensus_level":"medium","plddt":95.2993,"start":55,"end":234},{"cath_id":"3.80.10.10","chopping":"242-418","consensus_level":"medium","plddt":88.0885,"start":242,"end":418}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8N1E6","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8N1E6-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8N1E6-F1-predicted_aligned_error_v6.png","plddt_mean":91.88},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=FBXL14","jax_strain_url":"https://www.jax.org/strain/search?query=FBXL14"},"sequence":{"accession":"Q8N1E6","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8N1E6.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8N1E6/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8N1E6"}},"corpus_meta":[{"pmid":"19955572","id":"PMC_19955572","title":"The hypoxia-controlled FBXL14 ubiquitin ligase targets SNAIL1 for proteasome degradation.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19955572","citation_count":157,"is_preprint":false},{"pmid":"27923907","id":"PMC_27923907","title":"Deubiquitinase USP13 maintains glioblastoma stem cells by antagonizing FBXL14-mediated Myc ubiquitination.","date":"2016","source":"The Journal of experimental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/27923907","citation_count":129,"is_preprint":false},{"pmid":"26506454","id":"PMC_26506454","title":"F-box proteins: Keeping the epithelial-to-mesenchymal transition (EMT) in check.","date":"2015","source":"Seminars in cancer biology","url":"https://pubmed.ncbi.nlm.nih.gov/26506454","citation_count":110,"is_preprint":false},{"pmid":"31311807","id":"PMC_31311807","title":"BRD4 Promotes Gastric Cancer Progression and Metastasis through Acetylation-Dependent Stabilization of Snail.","date":"2019","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/31311807","citation_count":106,"is_preprint":false},{"pmid":"24157836","id":"PMC_24157836","title":"Nuclear ubiquitination by FBXL5 modulates Snail1 DNA binding and stability.","date":"2013","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/24157836","citation_count":85,"is_preprint":false},{"pmid":"23375009","id":"PMC_23375009","title":"Degradation of the transcription factor Twist, an oncoprotein that promotes cancer metastasis.","date":"2013","source":"Discovery medicine","url":"https://pubmed.ncbi.nlm.nih.gov/23375009","citation_count":67,"is_preprint":false},{"pmid":"32453420","id":"PMC_32453420","title":"Targeting CLK3 inhibits the progression of cholangiocarcinoma by reprogramming nucleotide metabolism.","date":"2020","source":"The Journal of experimental 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stimulates neuronal differentiation by targeting the Notch signaling factor HES1 for proteolysis.","date":"2017","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/29070679","citation_count":17,"is_preprint":false},{"pmid":"33801272","id":"PMC_33801272","title":"Insulin-Like Growth Factor Binding Protein-3 Exerts Its Anti-Metastatic Effect in Aerodigestive Tract Cancers by Disrupting the Protein Stability of Vimentin.","date":"2021","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/33801272","citation_count":14,"is_preprint":false},{"pmid":"35394261","id":"PMC_35394261","title":"Establishment and characterization of the third non-functional human pancreatic neuroendocrine tumor cell line.","date":"2022","source":"Human cell","url":"https://pubmed.ncbi.nlm.nih.gov/35394261","citation_count":13,"is_preprint":false},{"pmid":"37340421","id":"PMC_37340421","title":"NIPSNAP1 directs dual mechanisms to restrain senescence in cancer 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journal","url":"https://pubmed.ncbi.nlm.nih.gov/30450135","citation_count":5,"is_preprint":false},{"pmid":"35643547","id":"PMC_35643547","title":"Identification of the key exosomal lncRNAs/mRNAs in the serum during distraction osteogenesis.","date":"2022","source":"Journal of orthopaedic surgery and research","url":"https://pubmed.ncbi.nlm.nih.gov/35643547","citation_count":2,"is_preprint":false},{"pmid":"40051291","id":"PMC_40051291","title":"FBXL14 inhibits foam cell formation and atherosclerosis plaque progression by activating the NRF2 signal axis through ubiquitination of DUSP6.","date":"2025","source":"Journal of receptor and signal transduction research","url":"https://pubmed.ncbi.nlm.nih.gov/40051291","citation_count":1,"is_preprint":false},{"pmid":"36969608","id":"PMC_36969608","title":"Identification of hypertrophy-modulating Cullin-RING ubiquitin ligases in primary cardiomyocytes.","date":"2023","source":"Frontiers in physiology","url":"https://pubmed.ncbi.nlm.nih.gov/36969608","citation_count":1,"is_preprint":false},{"pmid":"41156030","id":"PMC_41156030","title":"Scaffold-Free Bone Regeneration Through Collaboration Between Type IV Collagen and FBXL14.","date":"2025","source":"Journal of clinical medicine","url":"https://pubmed.ncbi.nlm.nih.gov/41156030","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":14008,"output_tokens":4422,"usd":0.054177,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":12270,"output_tokens":4145,"usd":0.082488,"stage2_stop_reason":"end_turn"},"total_usd":0.136665,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2009,\n      \"finding\": \"FBXL14 (an F-box E3 ubiquitin ligase) directly interacts with SNAIL1 and promotes its polyubiquitylation and proteasome degradation independently of GSK-3β-mediated phosphorylation. shRNA-mediated inhibition of FBXL14 stabilizes both ectopically expressed and endogenous SNAIL1 in vivo. FBXL14 expression is down-regulated during hypoxia, which stabilizes SNAIL1.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitylation assay, shRNA knockdown, proteasome inhibitor assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP and ubiquitination assays with shRNA KD rescue, replicated across multiple cell lines and conditions in a focused mechanistic study\",\n      \"pmids\": [\"19955572\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"FBXL14 ubiquitinates c-Myc to promote its degradation in glioblastoma stem cells (GSCs). The deubiquitinase USP13 antagonizes FBXL14-mediated c-Myc ubiquitination, stabilizing c-Myc and maintaining GSC self-renewal. Overexpression of FBXL14 induces c-Myc degradation, promotes GSC differentiation, and inhibits tumor growth; the ubiquitin-insensitive T58A-c-Myc mutant rescues FBXL14 overexpression effects.\",\n      \"method\": \"Overexpression/knockdown, ubiquitination assay, rescue with ubiquitin-insensitive c-Myc mutant (T58A), tumor growth assays\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods including mutagenesis rescue, KD/OE with defined cellular phenotypes, and in vivo tumor assays in a single focused study\",\n      \"pmids\": [\"27923907\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"FBXL14 (referred to as Ppa/FBXL14) acts as a cytoplasmic ubiquitin ligase targeting SNAIL1. In the same study, FBXL5 was identified as a distinct nuclear ubiquitin ligase for SNAIL1, distinguishing the subcellular compartment of FBXL14-mediated versus FBXL5-mediated Snail1 degradation.\",\n      \"method\": \"shRNA screening, Co-immunoprecipitation, ubiquitination assay, subcellular fractionation\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and ubiquitination assays in a single lab, contextualizes FBXL14's cytoplasmic localization for Snail1 degradation\",\n      \"pmids\": [\"24157836\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"FBXL14 promotes proteasomal degradation of the EMT transcription factor Twist1. β-TRCP was additionally identified as a separate E3 ligase for Twist1, whose degradation requires IKKβ-mediated phosphorylation, distinguishing a phosphorylation-independent (FBXL14) from a phosphorylation-dependent (β-TRCP) mechanism.\",\n      \"method\": \"Protein stability assay, knockdown/overexpression, ubiquitination assay\",\n      \"journal\": \"Discovery medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, indirect evidence for FBXL14-Twist1 relationship referenced as prior finding; β-TRCP mechanism directly demonstrated\",\n      \"pmids\": [\"23375009\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"FBXL14 promotes polyubiquitination and proteasomal degradation of the EMT transcription factor Twist1. The compound Imipramine Blue (IB) suppresses Twist1-driven EMT in head and neck squamous cell carcinoma by enhancing FBXL14-mediated Twist1 polyubiquitination.\",\n      \"method\": \"Ubiquitination assay, co-immunoprecipitation, protein stability/degradation assay, shRNA knockdown\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ubiquitination assays and Co-IP in a single lab with pharmacological modulation, but limited mechanistic dissection of FBXL14-Twist1 interaction details\",\n      \"pmids\": [\"26257063\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"The SCF-FBXL14 complex ubiquitinates HES1 (hairy and enhancer of split 1) and promotes its proteasomal degradation. FBXL14 directly associates with HES1, and a conserved WRPW motif at the C-terminus of HES1 is essential for HES1 binding to FBXL14 and for ubiquitin-dependent HES1 degradation. SCF-FBXL14-mediated HES1 proteolysis stimulates neuronal differentiation.\",\n      \"method\": \"siRNA knockdown, co-immunoprecipitation, ubiquitination assay, HES1 half-life measurement, WRPW motif mutagenesis, neuronal differentiation assay in mES and F9 cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — Co-IP, ubiquitination assay, active-motif mutagenesis, and functional differentiation readout in a single focused study with multiple orthogonal methods\",\n      \"pmids\": [\"29070679\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"FBXL14 directly interacts with CDCP1 (CUB-domain-containing protein 1) and facilitates its ubiquitination and proteasomal degradation in triple-negative breast cancer cells, thereby suppressing breast cancer metastasis. miR-17/20a were shown to negatively control FBXL14 E3 ligase levels upstream.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, protein stability assay, overexpression/knockdown\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and ubiquitination assays with functional metastasis readout, single lab\",\n      \"pmids\": [\"29973690\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"LKB1 boosts the interaction between Snail1 and FBXL14, leading to increased ubiquitin-mediated Snail1 degradation. Metformin increases Snail1 ubiquitination via augmenting LKB1 cytoplasmic localization, placing LKB1 upstream of FBXL14-mediated Snail1 degradation.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, subcellular fractionation, overexpression/knockdown\",\n      \"journal\": \"Cancer science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and ubiquitination assays with pharmacological and genetic modulation in a single lab\",\n      \"pmids\": [\"29601127\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"BRD4, an acetylation reader, binds acetylated lysines K146 and K187 on Snail in an acetylation-dependent manner, thereby preventing Snail recognition by the E3 ubiquitin ligases FBXL14 and β-TrCP1, and inhibiting Snail polyubiquitination and proteasomal degradation.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, acetylation site mutagenesis, protein stability assay\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with mutagenesis in a single lab; FBXL14's role is indirectly demonstrated through competition with BRD4 for Snail binding\",\n      \"pmids\": [\"31311807\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CLK3 phosphorylates USP13 at Y708, which promotes USP13 binding to c-Myc and prevents FBXL14-mediated c-Myc ubiquitination, thereby activating purine metabolic gene transcription in cholangiocarcinoma. This places CLK3 upstream of the USP13/FBXL14 axis regulating c-Myc stability.\",\n      \"method\": \"In vitro kinase assay, co-immunoprecipitation, ubiquitination assay, phospho-site mutagenesis, metabolic profiling\",\n      \"journal\": \"The Journal of experimental medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — kinase assay and Co-IP with mutagenesis, single lab; FBXL14's role is part of the described pathway\",\n      \"pmids\": [\"32453420\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"IGFBP-3 directly binds vimentin and promotes vimentin's association with the E3 ligase FBXL14, causing vimentin proteasomal degradation. The C-terminal domain of IGFBP-3 and the head domain of vimentin are essential for their interaction.\",\n      \"method\": \"Co-immunoprecipitation, protein stability/degradation assay, domain-mapping with truncation mutants, in vitro and in vivo metastasis assays\",\n      \"journal\": \"Cancers\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with domain mapping and functional metastasis readout, single lab\",\n      \"pmids\": [\"33801272\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"FBXL14 (as the SCF-FBXL14 E3 ligase) binds RPA194 (the catalytic subunit of RNA Polymerase I) and mediates RPA194 ubiquitination and degradation in cancer cells treated with the Pol I inhibitor BMH-21. Mutation analysis in yeast identified lysines K1150, K1153, and K1156 on Rpa190 as relevant for protein degradation.\",\n      \"method\": \"RNAi screen, co-immunoprecipitation, ubiquitination assay, lysine-to-arginine mutagenesis in yeast, protein stability assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — RNAi screen followed by Co-IP, ubiquitination assay, and active-site mutagenesis with functional degradation readout in a single focused study\",\n      \"pmids\": [\"36372232\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"USP13 stabilizes Twist1 by specifically cleaving the K48-linked polyubiquitin chains of Twist1 induced by FBXL14. USP13 directly interacts with Twist1, and this axis promotes breast cancer cell migration and invasion. Additionally, Twist1 can inhibit USP13 transcriptional activity, forming a negative feedback loop.\",\n      \"method\": \"Co-immunoprecipitation, GST-pulldown, ubiquitination assay, Western blot, chromatin immunoprecipitation, luciferase reporter assay, migration/invasion assays, mouse lung metastasis assay\",\n      \"journal\": \"Cellular oncology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP and GST-pulldown confirming direct interaction, K48 linkage-specific ubiquitination assay, multiple orthogonal functional readouts\",\n      \"pmids\": [\"36732432\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"NIPSNAP1 sequesters FBXL14 to prevent FBXL14-mediated c-Myc ubiquitination and proteasomal turnover, thereby maintaining c-Myc levels in cancer cells and inhibiting P27-dependent senescence. c-Myc-Miz1 transcriptionally represses NIPSNAP1, establishing a feedback loop.\",\n      \"method\": \"Co-immunoprecipitation (NIPSNAP1-FBXL14 interaction), proteasome degradation assay, luciferase reporter assay, siRNA knockdown, xenograft model\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP demonstrating NIPSNAP1-FBXL14 complex with functional ubiquitination/degradation readout, single lab\",\n      \"pmids\": [\"37340421\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"β-Hydroxybutyrylation (Kbhb) of Snail at lysine K152 (mediated by CBP) stabilizes Snail by blocking recognition by FBXL14, preventing FBXL14-mediated Snail degradation and promoting cancer metastasis.\",\n      \"method\": \"Ubiquitination assay, co-immunoprecipitation, site-specific mutagenesis (K152), CBP inhibitor experiments, in vivo metastasis assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis and ubiquitination assay with pharmacological intervention, single lab; indirect demonstration of FBXL14 blockade\",\n      \"pmids\": [\"40675949\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"FBXL14 ubiquitinates DUSP6, promoting its degradation and thereby activating the NRF2 signaling pathway in macrophages, which inhibits foam cell formation and atherosclerotic inflammation.\",\n      \"method\": \"siRNA knockdown, overexpression, immunoprecipitation for ubiquitination, Western blot, bioinformatics-guided E3 ligase identification, in vivo ApoE-/- mouse model\",\n      \"journal\": \"Journal of receptor and signal transduction research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP ubiquitination assay with KD/OE and in vivo model, single lab, bioinformatics-guided candidate\",\n      \"pmids\": [\"40051291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"siRNA-mediated depletion of FBXL14 in neonatal rat cardiomyocytes results in decreased cell size under basal conditions, implicating FBXL14 as a positive regulator of cardiomyocyte hypertrophy.\",\n      \"method\": \"siRNA knockdown, automated microscopy cell size measurement, 3H-isoleucine incorporation assay\",\n      \"journal\": \"Frontiers in physiology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single functional screen with cell size readout only, no molecular substrate or pathway identified for FBXL14's role in this context\",\n      \"pmids\": [\"36969608\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"FBXL14 is the substrate-recognition subunit of an SCF-type E3 ubiquitin ligase complex that targets multiple short-lived proteins—including SNAIL1, Twist1, c-Myc, HES1, RPA194, CDCP1, vimentin, and DUSP6—for K48-linked polyubiquitination and proteasomal degradation, with its activity regulated by competing deubiquitinases (USP13), upstream kinases (LKB1, CLK3/USP13 axis), sequestering proteins (NIPSNAP1), and post-translational modifications on substrates (acetylation by BRD4, β-hydroxybutyrylation) that block substrate recognition, placing FBXL14 as a central post-translational regulator of EMT, stem cell maintenance, neuronal differentiation, ribosome biogenesis stress responses, and metabolic signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"FBXL14 is the substrate-recognition subunit of an SCF-type E3 ubiquitin ligase that targets multiple short-lived regulatory proteins for polyubiquitination and proteasomal degradation, positioning it as a post-translational gatekeeper of epithelial-mesenchymal transition (EMT), stem-cell maintenance, and differentiation [#0, #1, #5]. It directly binds and ubiquitinates the EMT transcription factor SNAIL1 in the cytoplasm, doing so independently of GSK-3\\u03b2 phosphorylation, and its downregulation under hypoxia stabilizes SNAIL1 [#0, #2]. Beyond SNAIL1, FBXL14 degrades a broad substrate set including Twist1 [#4], c-Myc [#1], HES1 via the substrate's C-terminal WRPW motif, thereby driving neuronal differentiation [#5], the RNA Polymerase I catalytic subunit RPA194 during Pol I inhibition stress [#11], CDCP1 to suppress breast cancer metastasis [#6], vimentin [#10], and DUSP6 to activate NRF2 signaling in macrophages [#15]. FBXL14 activity is constrained at several levels: the deubiquitinase USP13 reverses FBXL14-imposed K48-linked chains on c-Myc and Twist1 [#1, #12], NIPSNAP1 sequesters FBXL14 away from c-Myc [#13], LKB1 promotes the SNAIL1\\u2013FBXL14 interaction [#7], and substrate post-translational modifications\\u2014BRD4-read acetylation and CBP-mediated \\u03b2-hydroxybutyrylation of SNAIL\\u2014block FBXL14 recognition [#8, #14].\",\n  \"teleology\": [\n    {\n      \"year\": 2009,\n      \"claim\": \"Established FBXL14 as a bona fide E3 ligase by showing it directly degrades SNAIL1 through a phosphorylation-independent route, defining a parallel arm of EMT control distinct from GSK-3\\u03b2-dependent turnover.\",\n      \"evidence\": \"Co-IP, ubiquitination assay, and shRNA knockdown rescue across cell lines, with hypoxia-dependent downregulation\",\n      \"pmids\": [\"19955572\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the F-box/SCF complex composition\", \"Mechanism of FBXL14 downregulation under hypoxia not resolved\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Resolved where FBXL14 acts and broadened its substrate range, localizing FBXL14-mediated SNAIL1 degradation to the cytoplasm (distinct from nuclear FBXL5) and implicating Twist1 as an additional EMT-factor substrate.\",\n      \"evidence\": \"shRNA screening, subcellular fractionation, Co-IP and ubiquitination assays; Twist1 stability assays distinguishing phosphorylation-independent from \\u03b2-TRCP-dependent degradation\",\n      \"pmids\": [\"24157836\", \"23375009\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"FBXL14-Twist1 interaction interface not mapped in these studies\", \"Single-lab evidence for compartmentalization\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Connected FBXL14 to oncogenic c-Myc turnover and stem-cell fate, showing it degrades c-Myc to promote glioblastoma stem-cell differentiation, with USP13 acting as the opposing deubiquitinase.\",\n      \"evidence\": \"Overexpression/knockdown, ubiquitination assay, rescue with ubiquitin-insensitive T58A-c-Myc, and tumor growth assays\",\n      \"pmids\": [\"27923907\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether c-Myc recognition requires a specific degron not defined\", \"Direct competition kinetics between FBXL14 and USP13 not quantified\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Defined the substrate degron for one FBXL14 target, demonstrating that the conserved C-terminal WRPW motif of HES1 is required for binding and degradation, linking SCF-FBXL14 proteolysis to neuronal differentiation.\",\n      \"evidence\": \"siRNA knockdown, Co-IP, ubiquitination assay, HES1 half-life measurement, WRPW motif mutagenesis, and neuronal differentiation assays in mES and F9 cells\",\n      \"pmids\": [\"29070679\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether other substrates use analogous motifs unknown\", \"Structural basis of WRPW-FBXL14 recognition not solved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Extended FBXL14 substrate scope to CDCP1 and identified upstream regulatory inputs, with miR-17/20a controlling FBXL14 levels and LKB1 enhancing SNAIL1-FBXL14 association.\",\n      \"evidence\": \"Co-IP, ubiquitination and protein stability assays, knockdown/overexpression, subcellular fractionation, and metformin/LKB1 modulation\",\n      \"pmids\": [\"29973690\", \"29601127\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How LKB1 mechanistically promotes the SNAIL1-FBXL14 interaction unclear\", \"miR-17/20a regulation of FBXL14 is correlative at the level shown\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Showed that substrate post-translational modification gates FBXL14 access, as BRD4 binding to acetylated SNAIL lysines blocks recognition by FBXL14 (and \\u03b2-TrCP1), preventing degradation.\",\n      \"evidence\": \"Co-IP, ubiquitination assay, acetylation-site mutagenesis, and protein stability assays\",\n      \"pmids\": [\"31311807\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"FBXL14's role inferred from competition rather than directly assayed\", \"Single-lab evidence\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Placed a kinase upstream of the FBXL14-opposing deubiquitinase, showing CLK3 phosphorylates USP13 to enhance its c-Myc binding and shield c-Myc from FBXL14, coupling the axis to purine metabolism.\",\n      \"evidence\": \"In vitro kinase assay, Co-IP, ubiquitination assay, phospho-site mutagenesis, and metabolic profiling in cholangiocarcinoma\",\n      \"pmids\": [\"32453420\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"FBXL14 activity not directly measured, inferred via USP13 antagonism\", \"Single-lab pathway model\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified a scaffolding mechanism for substrate delivery, with IGFBP-3 bridging vimentin to FBXL14 to drive vimentin degradation and suppress metastasis.\",\n      \"evidence\": \"Co-IP, protein stability assays, domain mapping with truncation mutants, and in vitro/in vivo metastasis assays\",\n      \"pmids\": [\"33801272\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether IGFBP-3 is generally required for vimentin recognition unknown\", \"Single-lab evidence\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Revealed an unanticipated role in ribosome biogenesis stress, showing SCF-FBXL14 ubiquitinates and degrades the Pol I catalytic subunit RPA194 upon Pol I inhibition, with conserved lysines mapped in yeast.\",\n      \"evidence\": \"RNAi screen, Co-IP, ubiquitination assay, lysine-to-arginine mutagenesis in yeast, and protein stability assays\",\n      \"pmids\": [\"36372232\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Trigger linking Pol I inhibition to FBXL14 engagement not defined\", \"Physiological context beyond drug-induced stress unclear\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Detailed reversal and sequestration controls on FBXL14, with USP13 cleaving FBXL14-imposed K48 chains on Twist1 and NIPSNAP1 sequestering FBXL14 to spare c-Myc, each embedded in feedback loops; also implicated FBXL14 in cardiomyocyte hypertrophy.\",\n      \"evidence\": \"Co-IP, GST-pulldown, K48 linkage-specific ubiquitination, ChIP, migration/invasion and metastasis assays; separately, siRNA knockdown with cell-size and 3H-isoleucine incorporation in cardiomyocytes\",\n      \"pmids\": [\"36732432\", \"37340421\", \"36969608\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"NIPSNAP1 sequestration mechanism shown by Co-IP in a single lab\", \"Cardiomyocyte phenotype lacks an identified molecular substrate\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Expanded the modification-based evasion paradigm and extended FBXL14 into metabolic/inflammatory signaling, showing CBP-mediated \\u03b2-hydroxybutyrylation of SNAIL K152 blocks FBXL14 recognition, and that FBXL14 degrades DUSP6 to activate NRF2 in macrophages.\",\n      \"evidence\": \"Site-specific mutagenesis, ubiquitination assays, CBP inhibitor experiments, and in vivo metastasis and ApoE-/- atherosclerosis models\",\n      \"pmids\": [\"40675949\", \"40051291\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"DUSP6 degradation evidence is bioinformatics-guided and single-lab\", \"Whether multiple acyl modifications converge on the same SNAIL degron unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The structural basis by which FBXL14's leucine-rich repeats recognize its diverse substrate degrons, and the composition/regulation of the assembled SCF-FBXL14 holoenzyme, remain undefined across the corpus.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of FBXL14-substrate complexes\", \"Unifying degron logic across SNAIL1, Twist1, c-Myc, HES1, RPA194, CDCP1, vimentin, DUSP6 unknown\", \"In vivo loss-of-function phenotype of FBXL14 not established genetically\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1, 5, 11]},\n      {\"term_id\": \"GO:0016874\", \"supporting_discovery_ids\": [0, 5, 11]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 12, 13]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [2, 7]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 1, 5, 11]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"complexes\": [\"SCF (SKP1-CUL1-F-box) E3 ubiquitin ligase\"],\n    \"partners\": [\"SNAI1\", \"TWIST1\", \"MYC\", \"HES1\", \"RPA194\", \"USP13\", \"NIPSNAP1\", \"CDCP1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":4,"faith_total":4,"faith_pct":100.0}}