{"gene":"FBXL12","run_date":"2026-06-09T23:54:43","timeline":{"discoveries":[{"year":2013,"finding":"FBXL12 is the F-box protein subunit of an SCF (Skp1-Cul1-F-box) E3 ubiquitin ligase complex that recognizes and polyubiquitylates Ku80 upon its binding to DNA double-strand breaks (DSBs), leading to Ku80 removal from DNA and proteasomal degradation. Fbxl12 was found to be recruited to DSBs in a DSB- and Ku-dependent manner in Xenopus laevis egg extract; immunodepletion of Fbxl12 prevented Cul1 and Skp1 binding to DSBs and blocked Ku80 ubiquitylation. Uniquely, the F-box domain of Fbxl12 was required for binding to both Skp1 and its substrate Ku80.","method":"Cell-free Xenopus laevis egg extract system, immunodepletion, F-box protein screen for DSB-binding proteins, ubiquitylation assays","journal":"Cell cycle (Georgetown, Tex.)","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal immunodepletion in cell-free reconstitution system with multiple orthogonal readouts (recruitment, ubiquitylation, proteasomal degradation), domain mutagenesis","pmids":["23324393"],"is_preprint":false},{"year":2008,"finding":"FBXL12 (FBL12) forms an SCF(FBL12) E3 ubiquitin ligase complex and directly ubiquitinates the CDK inhibitor p57KIP2 in a phosphorylation-dependent manner. TGF-β1 stimulation induces p57KIP2 degradation via this pathway in osteoblasts. Inhibition of FBL12 by RNAi suppressed p57KIP2 degradation; a dominant-negative FBL12ΔF mutant increased steady-state p57KIP2 levels and promoted osteoblast differentiation, while wild-type FBL12 inhibited differentiation.","method":"Co-immunoprecipitation, in vitro ubiquitination assay, RNAi knockdown, dominant-negative overexpression, primary osteoblast differentiation assay","journal":"EMBO reports","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — in vitro ubiquitination assay plus RNAi and dominant-negative experiments with specific cellular phenotype, single lab","pmids":["18660753"],"is_preprint":false},{"year":2013,"finding":"Fbxl12 mediates the proteasomal degradation of CaMKI (Ca2+/calmodulin-dependent kinase I) via the ubiquitin-proteasome pathway, causing G1 arrest in lung epithelia. Fbxl12-induced CaMKI degradation disrupts cyclin D1/Cdk4 complex assembly and attenuates CaMKI-mediated phosphorylation of p27 at Thr157/Thr198 (human) or Thr170/Thr197 (mouse), altering p27 subcellular localization. Known inducers of G1 arrest increase Fbxl12 levels in cells.","method":"Overexpression and knockdown of Fbxl12, proteasome inhibitor experiments, p27 phosphorylation site mutagenesis, cell cycle analysis","journal":"Cellular signalling","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — loss-of-function and gain-of-function with defined cellular phenotype (G1 arrest) and substrate phosphorylation readout, single lab, methods not fully detailed in abstract","pmids":["23707388"],"is_preprint":false},{"year":2015,"finding":"FBXL12 interacts specifically with members of the ALDH3 family and mediates their polyubiquitylation, targeting ALDH3 for proteasomal degradation. This activity is essential for trophoblast stem cell (TSC) differentiation during placental development. FBXL12-deficient mice show ALDH3 accumulation in the placenta, impaired junctional zone formation, and a TSC differentiation defect that is phenocopied by forced ALDH3 expression in wild-type TSCs and rescued by ALDH3 inhibitor gossypol.","method":"Co-immunoprecipitation, in vivo ubiquitination assay, FBXL12 knockout mice, overexpression/rescue experiments in TSCs, ALDH3 inhibitor treatment","journal":"Stem cells (Dayton, Ohio)","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, in vivo ubiquitination, knockout phenotype with ALDH3 accumulation, phenocopy and chemical rescue, multiple orthogonal experiments","pmids":["26124079"],"is_preprint":false},{"year":2016,"finding":"The SCF(FBXL12) complex targets ALDH3 for degradation in thymocytes. FBXL12 is most abundant in CD4+CD8+ (DP) thymocytes and declines upon differentiation to SP cells. FBXL12-null mice show a differentiation block at the DP-to-SP transition associated with ALDH3 accumulation. This block is cell-autonomous, demonstrated by bone marrow transplants from FBXL12-null donors into wild-type recipients and by fetal thymic organ culture.","method":"FBXL12 knockout mice, bone marrow transplantation, fetal thymic organ culture, flow cytometry for T-cell subsets, protein level analysis","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"High","confidence_rationale":"Tier 2 / Moderate — knockout phenotype confirmed cell-autonomous by two orthogonal in vivo/ex vivo approaches (BMT, FTOC), mechanistically linked to ALDH3 accumulation","pmids":["26999371"],"is_preprint":false},{"year":2019,"finding":"Fbxl12 is an SCF subunit whose expression is induced by pre-TCR signaling at the β-selection stage of T cell development. The SCF(Fbxl12) complex targets Cdkn1b (p27) for polyubiquitination and proteasomal degradation, promoting cell cycle progression and proliferation of β-selected thymocytes. Fbxl12 and Fbxl1 (induced by Notch) function additively to degrade Cdkn1b.","method":"Genetic epistasis in mouse T cell development, conditional knockouts, polyubiquitination assays, cell cycle analysis, transcriptional induction assays","journal":"Nature immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis in vivo, polyubiquitination assay, multiple genetic perturbations identifying pathway position, published in high-impact journal","pmids":["31451788"],"is_preprint":false},{"year":2023,"finding":"CHK1-mediated phosphorylation of FANCD2 creates a phosphodegron that is recognized by FBXL12, triggering FANCD2 proteasomal degradation at stalled replication forks. This clears FANCD2 from chromatin and promotes replication fork restart under conditions of CYCLIN E- and drug-induced replication stress. Phosphodegron-mutant FANCD2 cannot rescue fork progression in FANCD2-deficient fibroblasts. In the absence of FBXL12, FANCD2 accumulates on chromatin, causing replication stress and excessive DNA damage. FBXL12 depletion sensitizes cancer cells to WEE1 inhibition.","method":"In vitro reconstitution with phosphodegron mutants, FBXL12 depletion, chromatin fractionation, DNA fiber assay, FANCD2-deficient cell complementation, drug sensitivity assays","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — reconstitution with phosphodegron mutants, chromatin fractionation, DNA fiber assays, multiple complementary approaches, published in Molecular Cell","pmids":["37591242"],"is_preprint":false},{"year":2024,"finding":"A neddylation/FBXL12-dependent process actively removes loaded Ku molecules from DNA ends throughout the cell cycle, restricting Ku accumulation to ~1–2 molecules per DNA end in cells. This mechanism operates in concert with DNA-PKcs (structural, not kinase activity) and a CtIP/ATM-dependent S-phase mechanism. Misregulation of Ku loading by disrupting FBXL12 leads to impaired transcription near DNA ends.","method":"FBXL12 depletion, neddylation inhibition, live-cell imaging, ChIP, transcription assays near DSBs","journal":"Cell reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — depletion experiments with functional consequence (transcription impairment), multiple perturbations, single lab","pmids":["39058590"],"is_preprint":false},{"year":2022,"finding":"Depletion of FBXL12 in G0 (quiescent) cells promotes extensive DNA end resection at DSBs, consistent with FBXL12's role in removing KU70/KU80 from DSBs to regulate the balance between NHEJ and resection-dependent repair pathways. This effect was specifically observed in G0 cells and not in proliferating G1 or G2 cells.","method":"CRISPR/Cas9 whole-genome screen, FBXL12 depletion, DNA end resection assays in G0 vs cycling cells","journal":"eLife","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — CRISPR screen followed by depletion with resection readout, single functional phenotype, single lab","pmids":["35575473"],"is_preprint":false},{"year":2015,"finding":"An intronic region of Fbxl12 acts as an alternative promoter, producing a short isoform of Fbl12 that lacks the F-box domain (Fbl12ΔF). UV irradiation increases Fbl12ΔF mRNA in cells. Fbl12ΔF can bind full-length Fbl12 and promote its relocalization from nucleus to cytoplasm, potentially modulating SCF(Fbl12) activity.","method":"Reporter assays for alternative promoter activity, RT-PCR, UV irradiation, co-immunoprecipitation, subcellular fractionation/localization","journal":"Biochemistry and biophysics reports","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — reporter assay, Co-IP for interaction, UV-induced expression change with localization readout, single lab","pmids":["29124172"],"is_preprint":false},{"year":2025,"finding":"FBXL12 catalyzes K63-linked ubiquitylation of Myosin heavy chain 14 (MYH14) in activated microglia, promoting cytoskeletal reorganization and migration. In the context of spinal cord injury, m6A modification of Fbxl12 mRNA specifically promotes FBXL12 synthesis in activated microglia, and FBXL12 overexpression maintains a scar-less healing microglial phenotype, reducing extracellular matrix deposition.","method":"Multiomics, m6A modification analysis, overexpression in microglia, K63-ubiquitylation assay, migration/cytoskeletal assays, in vivo spinal cord injury model","journal":"Signal transduction and targeted therapy","confidence":"Medium","confidence_rationale":"Tier 2–3 / Weak — K63-ubiquitylation assay identifies MYH14 as substrate, in vivo functional data, but single lab and abstract-level detail","pmids":["40830106"],"is_preprint":false},{"year":2025,"finding":"FBXL12 mediates ubiquitination of ALDH1A1, and this process is regulated by the sorcin-PAX5 signaling axis. Sorcin sequesters PAX5 in the cytoplasm, reducing FBXL12 expression and ALDH1A1 ubiquitination. Disruption of the sorcin-PAX5 interaction (e.g., by celastrol binding to Cys194 of sorcin) promotes PAX5 nuclear translocation, induces FBXL12 expression, increases ALDH1A1 ubiquitylation, and triggers ferroptosis in pancreatic cancer cells.","method":"Co-IP, ChIP, luciferase assays, proteomics, FBXL12 expression manipulation, ubiquitination assays, PAX5 translocation imaging","journal":"Journal of hematology & oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, ChIP, ubiquitination assay, functional rescue, multiple orthogonal methods, single lab","pmids":["40055736"],"is_preprint":false},{"year":2025,"finding":"CRY1 K151Q/R mutants show enhanced binding to FBXL12 (but not FBXL3) while exhibiting more stability than wild-type CRY1, without increased ubiquitination-linked degradation. This suggests FBXL12 interacts with CRY1 at K151 through a ubiquitination-independent mechanism that influences circadian period by modulating core clock protein interactions.","method":"Site-directed mutagenesis, luciferase complementation assay (protein-protein interaction), circadian rescue assay in Cry1/2-deficient cells","journal":"International journal of molecular sciences","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, luciferase complementation assay for interaction, no direct ubiquitination assay performed for this interaction, mechanistic interpretation is speculative","pmids":["40869282"],"is_preprint":false}],"current_model":"FBXL12 is the substrate-recognition subunit of an SCF (Skp1-Cul1-F-box) E3 ubiquitin ligase complex that polyubiquitylates multiple substrates—including Ku80 (at DNA double-strand breaks, facilitating NHEJ-to-HR pathway switching), p57KIP2 (in a phosphorylation-dependent manner regulating osteoblast differentiation), CaMKI (triggering G1 arrest), ALDH3/ALDH1A1 family members (controlling stem cell differentiation in trophoblasts and thymocytes), FANCD2 (after CHK1-dependent phosphorylation, promoting replication fork restart under replication stress), and MYH14 (K63-linked, promoting microglial cytoskeletal reorganization); its expression and activity are regulated by cell signaling (TGF-β, pre-TCR, Notch, CHK1, m6A mRNA modification), and an alternative F-box-lacking isoform (Fbl12ΔF) can modulate SCF(Fbxl12) activity by altering its subcellular localization."},"narrative":{"mechanistic_narrative":"FBXL12 is the substrate-recognition F-box subunit of an SCF (Skp1-Cul1-F-box) E3 ubiquitin ligase that controls cell-cycle progression, genome stability, and cell differentiation by directing the polyubiquitylation and proteasomal turnover of distinct substrates [PMID:23324393, PMID:18660753, PMID:26124079]. Unusually, its F-box domain mediates binding both to Skp1 and to substrate, as shown when SCF(FBXL12) recognizes Ku80 upon its loading at DNA double-strand breaks and removes it from DNA to regulate the balance between NHEJ and resection-dependent repair [PMID:23324393, PMID:35575473]; this neddylation-dependent clearance restricts Ku occupancy at DNA ends and preserves transcription near breaks [PMID:39058590]. In the replication-stress response, CHK1-dependent phosphorylation of FANCD2 generates a phosphodegron recognized by FBXL12, clearing FANCD2 from chromatin to permit replication fork restart, and FBXL12 loss causes FANCD2 accumulation, excessive DNA damage, and sensitization to WEE1 inhibition [PMID:37591242]. FBXL12 also enforces cell-cycle and differentiation transitions by degrading CDK inhibitors and metabolic enzymes: it targets p57KIP2 in a phosphorylation-dependent, TGF-β-induced manner in osteoblasts [PMID:18660753], degrades CaMKI to impose G1 arrest [PMID:23707388], degrades p27/Cdkn1b downstream of pre-TCR signaling to drive proliferation of β-selected thymocytes [PMID:31451788], and ubiquitylates ALDH3-family enzymes to enable trophoblast stem cell and DP-to-SP thymocyte differentiation in vivo [PMID:26124079, PMID:26999371]. Additional substrates and regulatory inputs include K63-linked ubiquitylation of MYH14 driving microglial cytoskeletal reorganization [PMID:40830106], ALDH1A1 ubiquitylation controlled by the sorcin-PAX5 axis in pancreatic cancer [PMID:40055736], and an alternative F-box-lacking isoform (Fbl12ΔF) that relocalizes full-length FBXL12 from nucleus to cytoplasm to modulate SCF(FBXL12) activity [PMID:29124172].","teleology":[{"year":2008,"claim":"Established FBXL12 as a functional SCF substrate-recognition subunit by identifying its first substrate and linking its activity to a signaling-driven differentiation outcome.","evidence":"Co-IP, in vitro ubiquitination, RNAi and dominant-negative FBL12ΔF in primary osteoblasts","pmids":["18660753"],"confidence":"High","gaps":["Phosphorylation site/kinase generating the p57KIP2 degron not defined","Single cell-type context"]},{"year":2013,"claim":"Showed FBXL12 acts in DNA repair by recognizing DNA-bound Ku80, defining a role beyond cell-cycle inhibitor turnover and revealing the unusual dual role of its F-box domain in Skp1 and substrate binding.","evidence":"Cell-free Xenopus egg extract, immunodepletion, F-box screen for DSB-binding proteins, ubiquitylation and degradation assays, domain mutagenesis","pmids":["23324393"],"confidence":"High","gaps":["Recruitment mechanism to DSBs in intact cells not resolved","Structural basis for F-box-mediated substrate binding unknown"]},{"year":2013,"claim":"Connected FBXL12 to G1 arrest by identifying CaMKI as a degradation substrate whose loss disrupts cyclin D1/Cdk4 assembly and p27 phosphorylation.","evidence":"Overexpression/knockdown, proteasome inhibition, p27 phosphosite mutagenesis, cell-cycle analysis in lung epithelia","pmids":["23707388"],"confidence":"Medium","gaps":["Direct ubiquitination of CaMKI by SCF(FBXL12) not reconstituted in this study","Methods detail limited"]},{"year":2015,"claim":"Demonstrated an in vivo developmental role by showing SCF(FBXL12) degrades ALDH3 to permit trophoblast stem cell differentiation, with knockout, phenocopy and chemical rescue.","evidence":"Reciprocal Co-IP, in vivo ubiquitination, FBXL12 knockout mice, TSC rescue, ALDH3 inhibitor gossypol","pmids":["26124079"],"confidence":"High","gaps":["Signal triggering ALDH3 degradation during differentiation not defined"]},{"year":2015,"claim":"Identified an alternative F-box-lacking isoform (Fbl12ΔF) as an endogenous regulatory mechanism that controls SCF(FBXL12) activity through subcellular relocalization.","evidence":"Alternative promoter reporter assays, RT-PCR, UV induction, Co-IP, subcellular fractionation","pmids":["29124172"],"confidence":"Medium","gaps":["Functional consequence of relocalization on specific substrates not measured","Physiological role of UV induction unclear"]},{"year":2016,"claim":"Generalized the FBXL12-ALDH3 axis to T-cell development, showing a cell-autonomous DP-to-SP differentiation block in knockouts.","evidence":"FBXL12 knockout mice, bone marrow transplantation, fetal thymic organ culture, flow cytometry","pmids":["26999371"],"confidence":"High","gaps":["How ALDH3 accumulation mechanistically blocks differentiation not resolved"]},{"year":2019,"claim":"Placed FBXL12 in pre-TCR signaling by showing its induction drives p27/Cdkn1b degradation to license β-selected thymocyte proliferation, acting additively with Notch-induced Fbxl1.","evidence":"In vivo genetic epistasis, conditional knockouts, polyubiquitination assays, cell-cycle analysis","pmids":["31451788"],"confidence":"High","gaps":["Mechanism of pre-TCR-driven transcriptional induction not detailed"]},{"year":2022,"claim":"Refined the DNA-repair role by showing FBXL12 depletion in quiescent G0 cells promotes DNA end resection, implicating it in NHEJ-versus-resection pathway choice.","evidence":"CRISPR/Cas9 whole-genome screen, FBXL12 depletion, resection assays in G0 versus cycling cells","pmids":["35575473"],"confidence":"Medium","gaps":["Why the effect is G0-specific not mechanistically explained","Single resection readout"]},{"year":2023,"claim":"Defined a phosphodegron-driven mechanism in which CHK1-phosphorylated FANCD2 is cleared from chromatin by FBXL12 to enable replication fork restart, with therapeutic implications.","evidence":"In vitro reconstitution with phosphodegron mutants, chromatin fractionation, DNA fiber assays, FANCD2-deficient cell complementation, WEE1-inhibitor sensitivity","pmids":["37591242"],"confidence":"High","gaps":["Structural recognition of the phosphodegron not solved"]},{"year":2024,"claim":"Quantified the FBXL12/neddylation pathway as restricting Ku occupancy to ~1–2 molecules per DNA end and linked its misregulation to impaired transcription near breaks.","evidence":"FBXL12 depletion, neddylation inhibition, live-cell imaging, ChIP, transcription assays near DSBs","pmids":["39058590"],"confidence":"Medium","gaps":["Coordination with DNA-PKcs and CtIP/ATM mechanisms not fully resolved","Single lab"]},{"year":2025,"claim":"Expanded the substrate range to K63-linked ubiquitylation of MYH14 in microglia and showed m6A modification of Fbxl12 mRNA tunes its expression during spinal cord injury healing.","evidence":"Multiomics, m6A analysis, overexpression in microglia, K63-ubiquitylation assay, migration/cytoskeletal assays, in vivo SCI model","pmids":["40830106"],"confidence":"Medium","gaps":["Non-degradative K63 function of MYH14 ubiquitylation mechanistically incomplete","Abstract-level detail"]},{"year":2025,"claim":"Linked FBXL12 to ferroptosis via ALDH1A1 ubiquitylation under control of the sorcin-PAX5 transcriptional axis in pancreatic cancer.","evidence":"Co-IP, ChIP, luciferase assays, proteomics, FBXL12 expression manipulation, ubiquitination assays, PAX5 imaging","pmids":["40055736"],"confidence":"Medium","gaps":["Direct vs indirect ALDH1A1 ubiquitylation not isolated from upstream transcriptional effects"]},{"year":2025,"claim":"Raised a non-canonical possibility that FBXL12 binds CRY1 at K151 to influence circadian period independent of ubiquitin-driven degradation.","evidence":"Site-directed mutagenesis, luciferase complementation interaction assay, circadian rescue in Cry1/2-deficient cells","pmids":["40869282"],"confidence":"Low","gaps":["No direct ubiquitination assay for the CRY1 interaction performed","Mechanistic interpretation speculative; not independently confirmed"]},{"year":null,"claim":"It remains unknown how FBXL12 selects among its many divergent substrates and how its localization, isoform expression, and post-transcriptional regulation are integrated to specify outcomes in different cell types.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of FBXL12 substrate recognition","Determinants of substrate choice across tissues undefined","Relationship between degradative and non-degradative interactions unclear"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,1,3,6,10]},{"term_id":"GO:0016874","term_label":"ligase activity","supporting_discovery_ids":[0,1,3]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[9]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[9]},{"term_id":"GO:0000228","term_label":"nuclear chromosome","supporting_discovery_ids":[0,6]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0,6,7,8]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1,2,5]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,1,3]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[3,4,5]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[4,5]}],"complexes":["SCF(FBXL12) (Skp1-Cul1-F-box) E3 ubiquitin ligase"],"partners":["SKP1","CUL1","KU80","FANCD2","CDKN1B","ALDH3","ALDH1A1","MYH14"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9NXK8","full_name":"F-box/LRR-repeat protein 12","aliases":["F-box and leucine-rich repeat protein 12","F-box protein FBL12"],"length_aa":326,"mass_kda":37.0,"function":"Substrate-recognition component of the SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex. Mediates the polyubiquitination and proteasomal degradation of CAMK1 leading to disruption of cyclin D1/CDK4 complex assembly which results in G1 cell cycle arrest in lung epithelia","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/Q9NXK8/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/FBXL12","classification":"Not Classified","n_dependent_lines":28,"n_total_lines":1208,"dependency_fraction":0.023178807947019868},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"PSME3","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/FBXL12","total_profiled":1310},"omim":[{"mim_id":"609079","title":"F-BOX AND LEUCINE-RICH REPEAT PROTEIN 12; FBXL12","url":"https://www.omim.org/entry/609079"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Mitochondria","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/FBXL12"},"hgnc":{"alias_symbol":["FLJ20188","Fbl12"],"prev_symbol":[]},"alphafold":{"accession":"Q9NXK8","domains":[{"cath_id":"1.20.1280","chopping":"10-44","consensus_level":"medium","plddt":92.5714,"start":10,"end":44},{"cath_id":"3.80.10.10","chopping":"45-178","consensus_level":"medium","plddt":89.3056,"start":45,"end":178},{"cath_id":"3.40.50","chopping":"204-209_227-318","consensus_level":"medium","plddt":90.4409,"start":204,"end":318}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NXK8","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NXK8-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NXK8-F1-predicted_aligned_error_v6.png","plddt_mean":89.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=FBXL12","jax_strain_url":"https://www.jax.org/strain/search?query=FBXL12"},"sequence":{"accession":"Q9NXK8","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9NXK8.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9NXK8/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NXK8"}},"corpus_meta":[{"pmid":"30526451","id":"PMC_30526451","title":"Leucine 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Oxidative, Metabolic, and Hormonal Markers Associated with Postpartum Disorder Susceptibility in Barki Sheep (Ovis aries).","date":"2025","source":"Veterinary sciences","url":"https://pubmed.ncbi.nlm.nih.gov/40266925","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":12104,"output_tokens":4127,"usd":0.049108,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11884,"output_tokens":4427,"usd":0.085047,"stage2_stop_reason":"end_turn"},"total_usd":0.134155,"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\": 2013,\n      \"finding\": \"FBXL12 is the F-box protein subunit of an SCF (Skp1-Cul1-F-box) E3 ubiquitin ligase complex that recognizes and polyubiquitylates Ku80 upon its binding to DNA double-strand breaks (DSBs), leading to Ku80 removal from DNA and proteasomal degradation. Fbxl12 was found to be recruited to DSBs in a DSB- and Ku-dependent manner in Xenopus laevis egg extract; immunodepletion of Fbxl12 prevented Cul1 and Skp1 binding to DSBs and blocked Ku80 ubiquitylation. Uniquely, the F-box domain of Fbxl12 was required for binding to both Skp1 and its substrate Ku80.\",\n      \"method\": \"Cell-free Xenopus laevis egg extract system, immunodepletion, F-box protein screen for DSB-binding proteins, ubiquitylation assays\",\n      \"journal\": \"Cell cycle (Georgetown, Tex.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal immunodepletion in cell-free reconstitution system with multiple orthogonal readouts (recruitment, ubiquitylation, proteasomal degradation), domain mutagenesis\",\n      \"pmids\": [\"23324393\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"FBXL12 (FBL12) forms an SCF(FBL12) E3 ubiquitin ligase complex and directly ubiquitinates the CDK inhibitor p57KIP2 in a phosphorylation-dependent manner. TGF-β1 stimulation induces p57KIP2 degradation via this pathway in osteoblasts. Inhibition of FBL12 by RNAi suppressed p57KIP2 degradation; a dominant-negative FBL12ΔF mutant increased steady-state p57KIP2 levels and promoted osteoblast differentiation, while wild-type FBL12 inhibited differentiation.\",\n      \"method\": \"Co-immunoprecipitation, in vitro ubiquitination assay, RNAi knockdown, dominant-negative overexpression, primary osteoblast differentiation assay\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro ubiquitination assay plus RNAi and dominant-negative experiments with specific cellular phenotype, single lab\",\n      \"pmids\": [\"18660753\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Fbxl12 mediates the proteasomal degradation of CaMKI (Ca2+/calmodulin-dependent kinase I) via the ubiquitin-proteasome pathway, causing G1 arrest in lung epithelia. Fbxl12-induced CaMKI degradation disrupts cyclin D1/Cdk4 complex assembly and attenuates CaMKI-mediated phosphorylation of p27 at Thr157/Thr198 (human) or Thr170/Thr197 (mouse), altering p27 subcellular localization. Known inducers of G1 arrest increase Fbxl12 levels in cells.\",\n      \"method\": \"Overexpression and knockdown of Fbxl12, proteasome inhibitor experiments, p27 phosphorylation site mutagenesis, cell cycle analysis\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — loss-of-function and gain-of-function with defined cellular phenotype (G1 arrest) and substrate phosphorylation readout, single lab, methods not fully detailed in abstract\",\n      \"pmids\": [\"23707388\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"FBXL12 interacts specifically with members of the ALDH3 family and mediates their polyubiquitylation, targeting ALDH3 for proteasomal degradation. This activity is essential for trophoblast stem cell (TSC) differentiation during placental development. FBXL12-deficient mice show ALDH3 accumulation in the placenta, impaired junctional zone formation, and a TSC differentiation defect that is phenocopied by forced ALDH3 expression in wild-type TSCs and rescued by ALDH3 inhibitor gossypol.\",\n      \"method\": \"Co-immunoprecipitation, in vivo ubiquitination assay, FBXL12 knockout mice, overexpression/rescue experiments in TSCs, ALDH3 inhibitor treatment\",\n      \"journal\": \"Stem cells (Dayton, Ohio)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, in vivo ubiquitination, knockout phenotype with ALDH3 accumulation, phenocopy and chemical rescue, multiple orthogonal experiments\",\n      \"pmids\": [\"26124079\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"The SCF(FBXL12) complex targets ALDH3 for degradation in thymocytes. FBXL12 is most abundant in CD4+CD8+ (DP) thymocytes and declines upon differentiation to SP cells. FBXL12-null mice show a differentiation block at the DP-to-SP transition associated with ALDH3 accumulation. This block is cell-autonomous, demonstrated by bone marrow transplants from FBXL12-null donors into wild-type recipients and by fetal thymic organ culture.\",\n      \"method\": \"FBXL12 knockout mice, bone marrow transplantation, fetal thymic organ culture, flow cytometry for T-cell subsets, protein level analysis\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — knockout phenotype confirmed cell-autonomous by two orthogonal in vivo/ex vivo approaches (BMT, FTOC), mechanistically linked to ALDH3 accumulation\",\n      \"pmids\": [\"26999371\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Fbxl12 is an SCF subunit whose expression is induced by pre-TCR signaling at the β-selection stage of T cell development. The SCF(Fbxl12) complex targets Cdkn1b (p27) for polyubiquitination and proteasomal degradation, promoting cell cycle progression and proliferation of β-selected thymocytes. Fbxl12 and Fbxl1 (induced by Notch) function additively to degrade Cdkn1b.\",\n      \"method\": \"Genetic epistasis in mouse T cell development, conditional knockouts, polyubiquitination assays, cell cycle analysis, transcriptional induction assays\",\n      \"journal\": \"Nature immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis in vivo, polyubiquitination assay, multiple genetic perturbations identifying pathway position, published in high-impact journal\",\n      \"pmids\": [\"31451788\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CHK1-mediated phosphorylation of FANCD2 creates a phosphodegron that is recognized by FBXL12, triggering FANCD2 proteasomal degradation at stalled replication forks. This clears FANCD2 from chromatin and promotes replication fork restart under conditions of CYCLIN E- and drug-induced replication stress. Phosphodegron-mutant FANCD2 cannot rescue fork progression in FANCD2-deficient fibroblasts. In the absence of FBXL12, FANCD2 accumulates on chromatin, causing replication stress and excessive DNA damage. FBXL12 depletion sensitizes cancer cells to WEE1 inhibition.\",\n      \"method\": \"In vitro reconstitution with phosphodegron mutants, FBXL12 depletion, chromatin fractionation, DNA fiber assay, FANCD2-deficient cell complementation, drug sensitivity assays\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — reconstitution with phosphodegron mutants, chromatin fractionation, DNA fiber assays, multiple complementary approaches, published in Molecular Cell\",\n      \"pmids\": [\"37591242\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"A neddylation/FBXL12-dependent process actively removes loaded Ku molecules from DNA ends throughout the cell cycle, restricting Ku accumulation to ~1–2 molecules per DNA end in cells. This mechanism operates in concert with DNA-PKcs (structural, not kinase activity) and a CtIP/ATM-dependent S-phase mechanism. Misregulation of Ku loading by disrupting FBXL12 leads to impaired transcription near DNA ends.\",\n      \"method\": \"FBXL12 depletion, neddylation inhibition, live-cell imaging, ChIP, transcription assays near DSBs\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — depletion experiments with functional consequence (transcription impairment), multiple perturbations, single lab\",\n      \"pmids\": [\"39058590\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Depletion of FBXL12 in G0 (quiescent) cells promotes extensive DNA end resection at DSBs, consistent with FBXL12's role in removing KU70/KU80 from DSBs to regulate the balance between NHEJ and resection-dependent repair pathways. This effect was specifically observed in G0 cells and not in proliferating G1 or G2 cells.\",\n      \"method\": \"CRISPR/Cas9 whole-genome screen, FBXL12 depletion, DNA end resection assays in G0 vs cycling cells\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — CRISPR screen followed by depletion with resection readout, single functional phenotype, single lab\",\n      \"pmids\": [\"35575473\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"An intronic region of Fbxl12 acts as an alternative promoter, producing a short isoform of Fbl12 that lacks the F-box domain (Fbl12ΔF). UV irradiation increases Fbl12ΔF mRNA in cells. Fbl12ΔF can bind full-length Fbl12 and promote its relocalization from nucleus to cytoplasm, potentially modulating SCF(Fbl12) activity.\",\n      \"method\": \"Reporter assays for alternative promoter activity, RT-PCR, UV irradiation, co-immunoprecipitation, subcellular fractionation/localization\",\n      \"journal\": \"Biochemistry and biophysics reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — reporter assay, Co-IP for interaction, UV-induced expression change with localization readout, single lab\",\n      \"pmids\": [\"29124172\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"FBXL12 catalyzes K63-linked ubiquitylation of Myosin heavy chain 14 (MYH14) in activated microglia, promoting cytoskeletal reorganization and migration. In the context of spinal cord injury, m6A modification of Fbxl12 mRNA specifically promotes FBXL12 synthesis in activated microglia, and FBXL12 overexpression maintains a scar-less healing microglial phenotype, reducing extracellular matrix deposition.\",\n      \"method\": \"Multiomics, m6A modification analysis, overexpression in microglia, K63-ubiquitylation assay, migration/cytoskeletal assays, in vivo spinal cord injury model\",\n      \"journal\": \"Signal transduction and targeted therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Weak — K63-ubiquitylation assay identifies MYH14 as substrate, in vivo functional data, but single lab and abstract-level detail\",\n      \"pmids\": [\"40830106\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"FBXL12 mediates ubiquitination of ALDH1A1, and this process is regulated by the sorcin-PAX5 signaling axis. Sorcin sequesters PAX5 in the cytoplasm, reducing FBXL12 expression and ALDH1A1 ubiquitination. Disruption of the sorcin-PAX5 interaction (e.g., by celastrol binding to Cys194 of sorcin) promotes PAX5 nuclear translocation, induces FBXL12 expression, increases ALDH1A1 ubiquitylation, and triggers ferroptosis in pancreatic cancer cells.\",\n      \"method\": \"Co-IP, ChIP, luciferase assays, proteomics, FBXL12 expression manipulation, ubiquitination assays, PAX5 translocation imaging\",\n      \"journal\": \"Journal of hematology & oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, ChIP, ubiquitination assay, functional rescue, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"40055736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CRY1 K151Q/R mutants show enhanced binding to FBXL12 (but not FBXL3) while exhibiting more stability than wild-type CRY1, without increased ubiquitination-linked degradation. This suggests FBXL12 interacts with CRY1 at K151 through a ubiquitination-independent mechanism that influences circadian period by modulating core clock protein interactions.\",\n      \"method\": \"Site-directed mutagenesis, luciferase complementation assay (protein-protein interaction), circadian rescue assay in Cry1/2-deficient cells\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, luciferase complementation assay for interaction, no direct ubiquitination assay performed for this interaction, mechanistic interpretation is speculative\",\n      \"pmids\": [\"40869282\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"FBXL12 is the substrate-recognition subunit of an SCF (Skp1-Cul1-F-box) E3 ubiquitin ligase complex that polyubiquitylates multiple substrates—including Ku80 (at DNA double-strand breaks, facilitating NHEJ-to-HR pathway switching), p57KIP2 (in a phosphorylation-dependent manner regulating osteoblast differentiation), CaMKI (triggering G1 arrest), ALDH3/ALDH1A1 family members (controlling stem cell differentiation in trophoblasts and thymocytes), FANCD2 (after CHK1-dependent phosphorylation, promoting replication fork restart under replication stress), and MYH14 (K63-linked, promoting microglial cytoskeletal reorganization); its expression and activity are regulated by cell signaling (TGF-β, pre-TCR, Notch, CHK1, m6A mRNA modification), and an alternative F-box-lacking isoform (Fbl12ΔF) can modulate SCF(Fbxl12) activity by altering its subcellular localization.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"FBXL12 is the substrate-recognition F-box subunit of an SCF (Skp1-Cul1-F-box) E3 ubiquitin ligase that controls cell-cycle progression, genome stability, and cell differentiation by directing the polyubiquitylation and proteasomal turnover of distinct substrates [#0, #1, #3]. Unusually, its F-box domain mediates binding both to Skp1 and to substrate, as shown when SCF(FBXL12) recognizes Ku80 upon its loading at DNA double-strand breaks and removes it from DNA to regulate the balance between NHEJ and resection-dependent repair [#0, #8]; this neddylation-dependent clearance restricts Ku occupancy at DNA ends and preserves transcription near breaks [#7]. In the replication-stress response, CHK1-dependent phosphorylation of FANCD2 generates a phosphodegron recognized by FBXL12, clearing FANCD2 from chromatin to permit replication fork restart, and FBXL12 loss causes FANCD2 accumulation, excessive DNA damage, and sensitization to WEE1 inhibition [#6]. FBXL12 also enforces cell-cycle and differentiation transitions by degrading CDK inhibitors and metabolic enzymes: it targets p57KIP2 in a phosphorylation-dependent, TGF-\\u03b2-induced manner in osteoblasts [#1], degrades CaMKI to impose G1 arrest [#2], degrades p27/Cdkn1b downstream of pre-TCR signaling to drive proliferation of \\u03b2-selected thymocytes [#5], and ubiquitylates ALDH3-family enzymes to enable trophoblast stem cell and DP-to-SP thymocyte differentiation in vivo [#3, #4]. Additional substrates and regulatory inputs include K63-linked ubiquitylation of MYH14 driving microglial cytoskeletal reorganization [#10], ALDH1A1 ubiquitylation controlled by the sorcin-PAX5 axis in pancreatic cancer [#11], and an alternative F-box-lacking isoform (Fbl12\\u0394F) that relocalizes full-length FBXL12 from nucleus to cytoplasm to modulate SCF(FBXL12) activity [#9].\",\n  \"teleology\": [\n    {\n      \"year\": 2008,\n      \"claim\": \"Established FBXL12 as a functional SCF substrate-recognition subunit by identifying its first substrate and linking its activity to a signaling-driven differentiation outcome.\",\n      \"evidence\": \"Co-IP, in vitro ubiquitination, RNAi and dominant-negative FBL12\\u0394F in primary osteoblasts\",\n      \"pmids\": [\"18660753\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Phosphorylation site/kinase generating the p57KIP2 degron not defined\", \"Single cell-type context\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed FBXL12 acts in DNA repair by recognizing DNA-bound Ku80, defining a role beyond cell-cycle inhibitor turnover and revealing the unusual dual role of its F-box domain in Skp1 and substrate binding.\",\n      \"evidence\": \"Cell-free Xenopus egg extract, immunodepletion, F-box screen for DSB-binding proteins, ubiquitylation and degradation assays, domain mutagenesis\",\n      \"pmids\": [\"23324393\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Recruitment mechanism to DSBs in intact cells not resolved\", \"Structural basis for F-box-mediated substrate binding unknown\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Connected FBXL12 to G1 arrest by identifying CaMKI as a degradation substrate whose loss disrupts cyclin D1/Cdk4 assembly and p27 phosphorylation.\",\n      \"evidence\": \"Overexpression/knockdown, proteasome inhibition, p27 phosphosite mutagenesis, cell-cycle analysis in lung epithelia\",\n      \"pmids\": [\"23707388\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct ubiquitination of CaMKI by SCF(FBXL12) not reconstituted in this study\", \"Methods detail limited\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Demonstrated an in vivo developmental role by showing SCF(FBXL12) degrades ALDH3 to permit trophoblast stem cell differentiation, with knockout, phenocopy and chemical rescue.\",\n      \"evidence\": \"Reciprocal Co-IP, in vivo ubiquitination, FBXL12 knockout mice, TSC rescue, ALDH3 inhibitor gossypol\",\n      \"pmids\": [\"26124079\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Signal triggering ALDH3 degradation during differentiation not defined\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identified an alternative F-box-lacking isoform (Fbl12\\u0394F) as an endogenous regulatory mechanism that controls SCF(FBXL12) activity through subcellular relocalization.\",\n      \"evidence\": \"Alternative promoter reporter assays, RT-PCR, UV induction, Co-IP, subcellular fractionation\",\n      \"pmids\": [\"29124172\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of relocalization on specific substrates not measured\", \"Physiological role of UV induction unclear\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Generalized the FBXL12-ALDH3 axis to T-cell development, showing a cell-autonomous DP-to-SP differentiation block in knockouts.\",\n      \"evidence\": \"FBXL12 knockout mice, bone marrow transplantation, fetal thymic organ culture, flow cytometry\",\n      \"pmids\": [\"26999371\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How ALDH3 accumulation mechanistically blocks differentiation not resolved\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Placed FBXL12 in pre-TCR signaling by showing its induction drives p27/Cdkn1b degradation to license \\u03b2-selected thymocyte proliferation, acting additively with Notch-induced Fbxl1.\",\n      \"evidence\": \"In vivo genetic epistasis, conditional knockouts, polyubiquitination assays, cell-cycle analysis\",\n      \"pmids\": [\"31451788\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of pre-TCR-driven transcriptional induction not detailed\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Refined the DNA-repair role by showing FBXL12 depletion in quiescent G0 cells promotes DNA end resection, implicating it in NHEJ-versus-resection pathway choice.\",\n      \"evidence\": \"CRISPR/Cas9 whole-genome screen, FBXL12 depletion, resection assays in G0 versus cycling cells\",\n      \"pmids\": [\"35575473\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Why the effect is G0-specific not mechanistically explained\", \"Single resection readout\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Defined a phosphodegron-driven mechanism in which CHK1-phosphorylated FANCD2 is cleared from chromatin by FBXL12 to enable replication fork restart, with therapeutic implications.\",\n      \"evidence\": \"In vitro reconstitution with phosphodegron mutants, chromatin fractionation, DNA fiber assays, FANCD2-deficient cell complementation, WEE1-inhibitor sensitivity\",\n      \"pmids\": [\"37591242\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural recognition of the phosphodegron not solved\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Quantified the FBXL12/neddylation pathway as restricting Ku occupancy to ~1\\u20132 molecules per DNA end and linked its misregulation to impaired transcription near breaks.\",\n      \"evidence\": \"FBXL12 depletion, neddylation inhibition, live-cell imaging, ChIP, transcription assays near DSBs\",\n      \"pmids\": [\"39058590\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Coordination with DNA-PKcs and CtIP/ATM mechanisms not fully resolved\", \"Single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Expanded the substrate range to K63-linked ubiquitylation of MYH14 in microglia and showed m6A modification of Fbxl12 mRNA tunes its expression during spinal cord injury healing.\",\n      \"evidence\": \"Multiomics, m6A analysis, overexpression in microglia, K63-ubiquitylation assay, migration/cytoskeletal assays, in vivo SCI model\",\n      \"pmids\": [\"40830106\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Non-degradative K63 function of MYH14 ubiquitylation mechanistically incomplete\", \"Abstract-level detail\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Linked FBXL12 to ferroptosis via ALDH1A1 ubiquitylation under control of the sorcin-PAX5 transcriptional axis in pancreatic cancer.\",\n      \"evidence\": \"Co-IP, ChIP, luciferase assays, proteomics, FBXL12 expression manipulation, ubiquitination assays, PAX5 imaging\",\n      \"pmids\": [\"40055736\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs indirect ALDH1A1 ubiquitylation not isolated from upstream transcriptional effects\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Raised a non-canonical possibility that FBXL12 binds CRY1 at K151 to influence circadian period independent of ubiquitin-driven degradation.\",\n      \"evidence\": \"Site-directed mutagenesis, luciferase complementation interaction assay, circadian rescue in Cry1/2-deficient cells\",\n      \"pmids\": [\"40869282\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No direct ubiquitination assay for the CRY1 interaction performed\", \"Mechanistic interpretation speculative; not independently confirmed\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown how FBXL12 selects among its many divergent substrates and how its localization, isoform expression, and post-transcriptional regulation are integrated to specify outcomes in different cell types.\",\n      \"evidence\": null,\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of FBXL12 substrate recognition\", \"Determinants of substrate choice across tissues undefined\", \"Relationship between degradative and non-degradative interactions unclear\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 1, 3, 6, 10]},\n      {\"term_id\": \"GO:0016874\", \"supporting_discovery_ids\": [0, 1, 3]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [9]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [9]},\n      {\"term_id\": \"GO:0000228\", \"supporting_discovery_ids\": [0, 6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 6, 7, 8]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1, 2, 5]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 1, 3]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [3, 4, 5]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [4, 5]}\n    ],\n    \"complexes\": [\"SCF(FBXL12) (Skp1-Cul1-F-box) E3 ubiquitin ligase\"],\n    \"partners\": [\"SKP1\", \"CUL1\", \"KU80\", \"FANCD2\", \"CDKN1B\", \"ALDH3\", \"ALDH1A1\", \"MYH14\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}