{"gene":"FANCL","run_date":"2026-06-09T23:54:43","timeline":{"discoveries":[{"year":2008,"finding":"FANCL acts as an E3 ubiquitin ligase that, together with the E2-conjugating enzyme Ube2t, is sufficient to monoubiquitinate FANCD2 in a minimal reconstituted system. A conserved RWD-like domain in FANCL stimulates monoubiquitination, and addition of FANCI enhances the reaction and restricts it to the correct in vivo lysine residue on FANCD2 (K561).","method":"In vitro reconstitution of monoubiquitination with purified Ube2t and FANCL; addition of FANCI to assess site restriction","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with purified components, domain-level dissection, replicated by multiple subsequent studies","pmids":["19111657"],"is_preprint":false},{"year":2004,"finding":"FANCL (PHF9), but not BRCA1, is the likely E3 ubiquitin ligase responsible for FANCD2 monoubiquitination. In FANCL-mutant cells, monoubiquitinated FANCD2 is absent from chromatin and nuclear matrix fractions, whereas non-ubiquitinated FANCD2 resides in the soluble fraction, demonstrating that FANCL-dependent monoubiquitination is required for FANCD2 chromatin association.","method":"Subcellular fractionation of FANCL-mutant vs. BRCA1-mutant cell lines; evolutionary co-existence analysis of FANCL and FANCD2","journal":"Cell cycle (Georgetown, Tex.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — fractionation with mutant cell lines plus evolutionary analysis; single lab, two orthogonal approaches","pmids":["14712086"],"is_preprint":false},{"year":2010,"finding":"Crystal structure of FANCL at 3.2 Å reveals three domains: an N-terminal E2-like fold (ELF domain), a novel double-RWD (DRWD) domain, and a C-terminal RING domain. Binding assays show the DRWD domain (not ELF) is responsible for substrate (FANCD2/FANCI) binding, while the RING domain mediates E2 (Ube2T) interaction.","method":"X-ray crystallography at 3.2 Å; domain-deletion binding assays","journal":"Nature structural & molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — atomic-resolution crystal structure combined with functional binding assays in a single rigorous study","pmids":["20154706"],"is_preprint":false},{"year":2014,"finding":"Crystal structure of the FANCL RING domain in complex with Ube2T reveals an extensive network of specific electrostatic and hydrophobic interactions beyond the generic E3–E2 interface, and mutagenesis shows these specific interactions are required for selective recruitment of Ube2T over other E2 enzymes by FANCL.","method":"X-ray crystallography of FANCL RING–Ube2T complex; site-directed mutagenesis of interface residues; E2 selectivity assays","journal":"Structure (London, England : 1993)","confidence":"High","confidence_rationale":"Tier 1 / Strong — atomic structure plus mutagenesis establishing functional determinants of E2 selectivity in one study","pmids":["24389026"],"is_preprint":false},{"year":2011,"finding":"Structure of the central (DRWD/URD) domain of human FANCL confirms conservation with Drosophila FANCL. Mutational analysis identifies residues in the DRWD domain required for binding FANCD2 and FANCI substrates, and a separate region required for Ube2T binding.","method":"X-ray crystallography of central domain; mutagenesis; binding assays with FANCD2, FANCI, and Ube2T","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure with systematic mutagenesis and interaction assays defining functional residues","pmids":["21775430"],"is_preprint":false},{"year":2006,"finding":"The WD40 repeats (not the PHD/RING domain) of FANCL are required for interaction with other FA core complex subunits. The PHD domain is dispensable for core complex incorporation but is required for FANCD2 monoubiquitination; a conserved tryptophan in the PHD analogous to the c-CBL RING finger is required for in vitro auto-ubiquitination and in vivo FANCD2 monoubiquitination.","method":"Domain-deletion and point-mutation constructs expressed in FANCL-deficient cells; co-immunoprecipitation; in vitro ubiquitination assay; MMC resistance complementation","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal domain dissection with multiple orthogonal functional readouts (co-IP, in vitro ubiquitination, MMC resistance)","pmids":["16474167"],"is_preprint":false},{"year":2007,"finding":"FANCL physically interacts with FANCD2 via its PHD domain (co-immunoprecipitation in 293T cells and yeast two-hybrid). FANCL is required for FANCD2 monoubiquitination and focus formation in DT40 cells, and loss of FANCL (or FANCD2 monoubiquitination) causes quantitatively identical defects in homologous recombination repair of I-SceI-induced chromosomal breaks.","method":"Yeast two-hybrid; co-immunoprecipitation; FANCL gene disruption in DT40 cells; I-SceI HR repair assay; focus formation immunoassay","journal":"Genes to cells : devoted to molecular & cellular mechanisms","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal interactions plus genetic epistasis placing FANCL upstream of FANCD2 monoubiquitination in HR repair; replicated in avian and human cell systems","pmids":["17352736"],"is_preprint":false},{"year":2009,"finding":"The UBE2T–FANCL pair can monoubiquitinate FANCI on Lys-523 in vitro. FANCI binds branched DNA structures through its C-terminal fragment, a binding activity that likely positions it as a substrate.","method":"In vitro ubiquitination assay with purified UBE2T and FANCL; DNA binding assay with branched DNA substrates","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution demonstrating FANCI as a direct FANCL/UBE2T substrate; single lab, multiple biochemical methods","pmids":["19589784"],"is_preprint":false},{"year":2010,"finding":"UBE2W interacts with the PHD domain of FANCL (the PHD domain is necessary and sufficient for this interaction) and catalyzes monoubiquitination of the FANCL PHD domain in vitro. UBE2W overexpression promotes FANCD2 monoubiquitination in cells, and UBE2W knockdown reduces UV-induced (but not MMC-induced) FANCD2 monoubiquitination, indicating UBE2W regulates FANCD2 monoubiquitination through FANCL by a mechanism distinct from UBE2T.","method":"Co-immunoprecipitation; domain-deletion mapping; in vitro ubiquitination assay; siRNA knockdown with FANCD2 monoubiquitination readout","journal":"Molecules and cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP domain mapping plus in vitro ubiquitination and cellular knockdown; single lab, multiple complementary methods","pmids":["21229326"],"is_preprint":false},{"year":2015,"finding":"The N-terminal ELF domain of FANCL mediates a non-covalent interaction with ubiquitin via the canonical Ile44 patch on ubiquitin. This interaction is not required for FANCD2 monoubiquitination in vitro, nor for core complex recognition or Ube2T binding, but is required for efficient DNA damage-induced FANCD2 monoubiquitination in vertebrate cells, indicating a regulatory in vivo function for ubiquitin binding by the ELF domain.","method":"NMR/binding assays for ELF–ubiquitin interaction; mutagenesis of ubiquitin Ile44 patch and corresponding FANCL patch; in vitro ubiquitination assay; cellular complementation assay for damage-induced FANCD2 monoubiquitination","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — structural/biophysical interaction mapping plus mutagenesis and cellular functional validation; single lab but multiple orthogonal methods","pmids":["26149689"],"is_preprint":false},{"year":2012,"finding":"FANCL ubiquitinates β-catenin with atypical lysine-11 ubiquitin chain extension (non-proteolytic), enhancing β-catenin nuclear activity and transcription of Wnt targets c-Myc and Cyclin D1. FANCL-deficient cells show diminished β-catenin activation, and suppression of FANCL in human CD34+ stem/progenitor cells reduces β-catenin-active cells and inhibits multilineage progenitor expansion.","method":"Co-immunoprecipitation; in vitro ubiquitination assay; LEF/TCF reporter assay; immunofluorescence; FANCL knockdown in human CD34+ cells with colony/progenitor readout","journal":"Blood","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro ubiquitination plus reporter assay and primary stem cell functional readout; single lab, multiple methods","pmids":["22653977"],"is_preprint":false},{"year":2013,"finding":"FANCL protein is constitutively targeted for proteasomal degradation via K48-linked polyubiquitination. The ELF (E2-like fold) domain may direct this polyubiquitination. FANCL is stabilized in a complex with axin1 when GSK-3β is overexpressed, and constitutively active Akt (myristoylated) increases FANCL steady-state levels by reducing K48-linked polyubiquitination. Phosphorylated (acidic) forms of FANCL are not subject to polyubiquitination.","method":"Proteasome inhibitor treatment; K48-linkage-specific ubiquitination assay; N-terminal deletion constructs; co-immunoprecipitation with axin1/GSK-3β; 2D-PAGE phospho-FANCL analysis; constitutively active Akt expression","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple biochemical approaches in single lab establishing a post-translational stability mechanism","pmids":["23783032"],"is_preprint":false},{"year":2017,"finding":"Arsenite (As3+) binds directly to the PHD/RING finger domain of FANCL both in vitro and in cells. This binding compromises FANCL-mediated FANCD2 ubiquitination in cells, reduces FANCD2 chromatin recruitment to DNA damage sites, and renders cells more sensitive to DNA interstrand cross-linking agents.","method":"In vitro binding assay (recombinant FANCL PHD/RING + arsenite); cellular As3+ treatment with FANCD2 monoubiquitination and chromatin recruitment readout; clonogenic survival assay","journal":"ACS chemical biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding assay plus cellular functional readouts; single lab, multiple complementary methods","pmids":["28535027"],"is_preprint":false},{"year":2019,"finding":"A small-molecule inhibitor identified by high-throughput screening inhibits UBE2T/FANCL-mediated FANCD2 monoubiquitylation and sensitizes cells to the DNA cross-linking agent carboplatin, validating the UBE2T–FANCL catalytic pair as a druggable target in the FA pathway.","method":"High-throughput biochemical screen; in vitro ubiquitylation assay; cellular FANCD2 monoubiquitylation assay; clonogenic survival with carboplatin","journal":"ACS chemical biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — biochemical screen with cellular validation; single lab, multiple orthogonal readouts","pmids":["31525021"],"is_preprint":false},{"year":2022,"finding":"FANCL protein localizes to mitochondria (in both basal and mitochondrial stress conditions), and its ubiquitin ligase activity is not required for this mitochondrial localization. CRISPR/Cas9 knockout of FANCL in parkin-overexpressing HeLa cells impairs clearance of damaged mitochondria (mitophagy) upon oligomycin/antimycin treatment; this defect is rescued by reintroduction of either wild-type FANCL or the catalytically dead FANCL(C307A) mutant, demonstrating a ubiquitin ligase-independent role in supporting Parkin-mediated mitophagy.","method":"Subcellular fractionation/mitochondrial localization; CRISPR/Cas9 KO; mitophagy assay (mitochondrial clearance upon OA stress); complementation with WT and C307A catalytic mutant","journal":"Biochimica et biophysica acta. Molecular basis of disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO with specific phenotypic readout and catalytic-mutant rescue demonstrating ligase-independent function; single lab","pmids":["35644338"],"is_preprint":false},{"year":2006,"finding":"In Drosophila, FANCL is necessary for monoubiquitination of FANCD2, and epistasis analysis places FANCL upstream of FANCD2 in a linear DNA repair pathway. Knockdown of either FANCL or FANCD2 confers hypersensitivity to cross-linking agents.","method":"RNAi knockdown in Drosophila; cross-linking agent sensitivity assay; FANCD2 monoubiquitination Western blot; genetic epistasis","journal":"DNA repair","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis in Drosophila model with functional readouts; single study but ortholog-consistent with mammalian data","pmids":["16860002"],"is_preprint":false},{"year":2002,"finding":"Mouse Pog (the ortholog of FANCL) is necessary for primordial germ cell (PGC) proliferation between E9.5 and E10.25 dpc. Deletion of Pog causes the germ-cell-deficient (gcd) phenotype with reduced PGC numbers and adult sterility; the proliferation defect rather than aberrant migration is responsible.","method":"Targeted Pog knockout mice; PGC counting at multiple developmental time points; comparison with gcd insertional mutant","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mouse KO with defined cellular phenotype; single lab but clear loss-of-function result","pmids":["12417526"],"is_preprint":false},{"year":2003,"finding":"POG (FANCL ortholog) interacts with GGN1 and GGN3 (gametogenetin isoforms) via yeast two-hybrid and co-expression in HeLa cells. Co-expression of POG with GGN1 or GGN3 relocalizes POG to the perinuclear region or nucleoli, respectively, and Pog-deficient mice show impaired meiosis during spermatogenesis.","method":"Yeast two-hybrid; co-expression in HeLa cells with localization readout; Pog-knockout mouse spermatogenesis analysis","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — yeast two-hybrid interaction plus cellular co-localization and mouse KO phenotype; single lab, consistent across methods","pmids":["12574169"],"is_preprint":false},{"year":2010,"finding":"In zebrafish, fancl is expressed in developing germ cells at the critical time of sexual fate determination. Loss of fancl causes Tp53-mediated germ cell apoptosis (demonstrated by caspase-3 immunoassay), compromises oocyte survival through meiosis, and results in female-to-male sex reversal. Introduction of a tp53 mutation into fancl mutants rescues sex reversal by reducing germ cell apoptosis.","method":"fancl mutant zebrafish; caspase-3 immunoassay; cyp19a1a and amh expression analysis; tp53;fancl double mutant genetic epistasis; fertility assay","journal":"PLoS genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (expression analysis, apoptosis assay, double-mutant epistasis) in zebrafish model establishing mechanism; well-controlled study","pmids":["20661450"],"is_preprint":false},{"year":2020,"finding":"Two heterozygous frameshift mutations in FANCL (c.1048_1051delGTCT and c.739dupA) identified in POI patients cause cytoplasmic retention of mutant FANCL protein (whereas wild-type FANCL is nuclear), impaired ubiquitin-ligase activity, and compromised DNA repair after mitomycin C treatment.","method":"Subcellular localization of mutant vs. WT FANCL by immunofluorescence; in vitro ubiquitin ligase activity assay; MMC DNA repair assay in patient-derived cells","journal":"Human mutation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization plus biochemical activity assays on patient variants; single lab, multiple methods","pmids":["32048394"],"is_preprint":false},{"year":2026,"finding":"A murine FanclTATΔ allele removing the catalytic cysteine in the RING domain generates a core complex that retains structural integrity but lacks FANCD2 monoubiquitination activity. Homozygous mice phenocopy human FA (infertility, craniofacial anomalies, DNA damage hypersensitivity, progressive HSC loss). CRISPR-Cas9 or prime editing correction of the mutation restores FANCD2 monoubiquitination and DNA damage resistance in myeloid cells, demonstrating that loss of RING E3 ligase activity alone explains all major FA phenotypes.","method":"CRISPR knock-in mouse model; biochemical FANCD2 monoubiquitination assay; mouse phenotyping; CRISPR-Cas9 and prime editing correction with functional rescue","journal":"Blood advances","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — catalytic-residue knock-in plus genetic correction with multiple orthogonal phenotypic and biochemical readouts; comprehensive mechanistic validation","pmids":["41259745"],"is_preprint":false},{"year":2020,"finding":"Analysis of 17 FANCL URD-domain variants from patient cancer cells shows that mutations I136V, L154S, W212A, L214A, R221W, R221C, and V287G destabilize FANCL, while E217K, T224K, M247V, and the hydrophobic patch mutants (L248A, F252A, L254A, I265A) impair catalytic function without destabilizing the fold. N270K and E289Q specifically destabilize the C-terminal helices of the URD domain. These functional defects correlate with cellular sensitivity to an interstrand cross-linking agent.","method":"Recombinant expression; thermal shift assay; FANCD2 interaction assay; in vitro ubiquitination assay; cellular ICL sensitivity assay","journal":"Bioscience reports","confidence":"Medium","confidence_rationale":"Tier 1–2 / Moderate — systematic biochemical and structural characterization with cellular validation; single lab, multiple orthogonal methods","pmids":["32420600"],"is_preprint":false}],"current_model":"FANCL is the RING-type E3 ubiquitin ligase subunit of the Fanconi anemia core complex; its three-domain architecture (ELF, DRWD/URD, RING) assigns distinct roles—the RING domain selectively recruits the E2 enzyme UBE2T, the central DRWD domain recognizes the FANCD2/FANCI substrate dimer, and the ELF domain binds free ubiquitin to promote efficient damage-induced monoubiquitination in vivo. Together with UBE2T, FANCL monoubiquitinates FANCD2 and FANCI in a reaction stimulated by FANCI and restricted to the correct lysine, targeting the ID complex to chromatin for homologous recombination repair of interstrand crosslinks; FANCL also ubiquitinates β-catenin with K11-linked chains to enhance Wnt signaling in hematopoietic stem cells, supports Parkin-mediated mitophagy in a ligase-independent manner, and is required for primordial germ cell proliferation and oocyte survival through meiosis."},"narrative":{"mechanistic_narrative":"FANCL is the catalytic RING-type E3 ubiquitin ligase subunit of the Fanconi anemia core complex, partnering with the E2 enzyme UBE2T to monoubiquitinate FANCD2 and FANCI and thereby drive homologous-recombination repair of DNA interstrand crosslinks [PMID:19111657, PMID:17352736]. Its crystal structure resolves a tripartite architecture in which the central DRWD/URD domain binds the FANCD2/FANCI substrate dimer while the C-terminal RING domain mediates E2 recruitment, and an extensive electrostatic/hydrophobic RING–UBE2T interface confers selective recruitment of UBE2T over other E2 enzymes [PMID:20154706, PMID:24389026]. Reconstitution shows FANCL and UBE2T are sufficient to monoubiquitinate FANCD2, with FANCI both stimulating the reaction and restricting modification to the correct lysine (K561 on FANCD2; K523 on FANCI) [PMID:19111657, PMID:19589784]; the N-terminal ELF domain additionally binds free ubiquitin via the Ile44 patch to promote efficient damage-induced FANCD2 monoubiquitination in cells [PMID:26149689]. FANCL-dependent monoubiquitination is required for FANCD2 chromatin and nuclear-matrix association and for HR repair of induced chromosomal breaks, an epistatic relationship conserved from Drosophila to vertebrates [PMID:14712086, PMID:17352736, PMID:16860002]. A catalytic-cysteine knock-in mouse establishes that loss of RING E3 ligase activity alone reproduces all major Fanconi anemia phenotypes, and FANCL variants causing protein destabilization or cytoplasmic mislocalization underlie premature ovarian insufficiency [PMID:41259745, PMID:32048394]. Beyond DNA repair, FANCL extends K11-linked non-proteolytic ubiquitin chains on β-catenin to enhance Wnt target transcription in hematopoietic stem/progenitor cells [PMID:22653977], supports Parkin-mediated mitophagy through a ubiquitin ligase-independent mitochondrial function [PMID:35644338], and is required for primordial germ cell proliferation and oocyte survival through meiosis [PMID:12417526, PMID:20661450].","teleology":[{"year":2002,"claim":"Before its biochemical role was known, the FANCL ortholog was shown to be developmentally essential, establishing a germ-cell function distinct from any later-defined enzymatic activity.","evidence":"Targeted Pog knockout mice with primordial germ cell counting across developmental time points","pmids":["12417526"],"confidence":"Medium","gaps":["Molecular mechanism of the proliferation defect not defined","No link to ubiquitination established at this stage"]},{"year":2003,"claim":"Identification of GGN1/GGN3 as POG interactors that relocalize the protein addressed where and with what partners FANCL acts during gametogenesis.","evidence":"Yeast two-hybrid and HeLa co-expression with localization readout, plus Pog-knockout spermatogenesis analysis","pmids":["12574169"],"confidence":"Medium","gaps":["Functional consequence of GGN binding for ligase activity unknown","Interactions not validated in germ cells in vivo"]},{"year":2004,"claim":"The question of which factor monoubiquitinates FANCD2 was narrowed to FANCL, linking its activity to FANCD2 chromatin localization.","evidence":"Subcellular fractionation of FANCL- vs BRCA1-mutant cells plus evolutionary co-existence analysis","pmids":["14712086"],"confidence":"Medium","gaps":["No reconstitution showing direct ligase activity","E2 partner not identified"]},{"year":2006,"claim":"Domain dissection separated FANCL's structural role in the core complex from its catalytic role, and Drosophila epistasis placed FANCL upstream of FANCD2 in a linear repair pathway.","evidence":"Domain-deletion/point mutants in FANCL-deficient cells with co-IP, in vitro ubiquitination, MMC complementation; RNAi epistasis in Drosophila","pmids":["16474167","16860002"],"confidence":"Medium","gaps":["E2 enzyme identity unresolved","Atomic basis of substrate vs core-complex binding not defined"]},{"year":2007,"claim":"Genetic and physical evidence established FANCL as required for FANCD2 monoubiquitination, focus formation, and HR repair, quantitatively coupling its activity to recombination outcome.","evidence":"Yeast two-hybrid, co-IP, FANCL disruption in DT40 cells, I-SceI HR assay, focus formation","pmids":["17352736"],"confidence":"High","gaps":["Reconstitution with defined components still lacking","Site specificity of modification unaddressed"]},{"year":2008,"claim":"Minimal reconstitution proved FANCL plus UBE2T are sufficient to monoubiquitinate FANCD2, and that FANCI confers site specificity — defining the core catalytic logic of the FA pathway.","evidence":"In vitro reconstitution with purified UBE2T and FANCL; FANCI addition to assess K561 site restriction","pmids":["19111657"],"confidence":"High","gaps":["Structural basis of E2 and substrate selection not yet resolved","Mechanism of FANCI-driven site restriction not defined"]},{"year":2009,"claim":"FANCI was shown to be a direct second substrate of the UBE2T–FANCL pair, broadening the enzyme's targets within the ID complex.","evidence":"In vitro ubiquitination with purified UBE2T/FANCL on FANCI K523; branched DNA binding assay","pmids":["19589784"],"confidence":"High","gaps":["Order/coordination of FANCD2 vs FANCI modification in vivo unclear","Role of DNA binding in substrate positioning not directly tested"]},{"year":2010,"claim":"The crystal structure assigned distinct molecular functions to FANCL's three domains, defining DRWD as the substrate-binding module and RING as the E2-interaction module.","evidence":"X-ray crystallography at 3.2 Å with domain-deletion binding assays","pmids":["20154706"],"confidence":"High","gaps":["Determinants of E2 selectivity not resolved at residue level","Role of ELF domain undefined"]},{"year":2010,"claim":"A non-canonical E2 (UBE2W) acting on FANCL's PHD domain was found to regulate FANCD2 monoubiquitination via a UV-specific route distinct from UBE2T.","evidence":"Co-IP domain mapping, in vitro ubiquitination, and siRNA knockdown with FANCD2 readout","pmids":["21229326"],"confidence":"Medium","gaps":["Physiological significance of FANCL PHD monoubiquitination unclear","Single-lab finding not independently reproduced"]},{"year":2010,"claim":"Zebrafish work revealed FANCL safeguards germ cell survival through meiosis by suppressing Tp53-dependent apoptosis, mechanistically explaining its sex-determination role.","evidence":"fancl mutant zebrafish, caspase-3 assay, tp53;fancl double-mutant epistasis, fertility assay","pmids":["20661450"],"confidence":"High","gaps":["Whether germ-cell role depends on ligase activity not tested here","Connection to ICL repair in germ cells not established"]},{"year":2011,"claim":"Structure and mutagenesis of the central DRWD/URD domain pinpointed the residues for FANCD2/FANCI binding versus UBE2T binding, refining the substrate-recognition map.","evidence":"X-ray crystallography of the central domain with mutagenesis and binding assays","pmids":["21775430"],"confidence":"High","gaps":["Dynamics of substrate handoff to the RING-bound E2 unresolved"]},{"year":2012,"claim":"FANCL was shown to extend atypical K11-linked, non-proteolytic chains on β-catenin, defining a DNA-repair-independent role in Wnt signaling and HSC progenitor expansion.","evidence":"Co-IP, in vitro ubiquitination, LEF/TCF reporter, and FANCL knockdown in CD34+ cells","pmids":["22653977"],"confidence":"Medium","gaps":["E2 partner for β-catenin chains not identified","In vivo relevance to leukemogenesis not established"]},{"year":2013,"claim":"FANCL's own stability was placed under post-translational control, with K48-linked degradation modulated by phosphorylation and the Akt/GSK-3β/axin1 axis.","evidence":"Proteasome inhibition, K48-linkage ubiquitination assay, N-terminal deletions, axin1/GSK-3β co-IP, 2D-PAGE, active Akt expression","pmids":["23783032"],"confidence":"Medium","gaps":["Responsible E3 for FANCL K48 chains not identified","Physiological trigger for FANCL turnover unclear"]},{"year":2014,"claim":"The RING–UBE2T co-crystal structure explained how FANCL selectively recruits its cognate E2 through interactions beyond the generic E3–E2 interface.","evidence":"X-ray crystallography of FANCL RING–UBE2T with interface mutagenesis and E2 selectivity assays","pmids":["24389026"],"confidence":"High","gaps":["Conformational activation of the E2~Ub for transfer not resolved"]},{"year":2015,"claim":"The ELF domain's non-covalent ubiquitin binding was assigned a regulatory role specifically enabling efficient damage-induced FANCD2 monoubiquitination in cells.","evidence":"NMR/binding assays, Ile44-patch mutagenesis, in vitro ubiquitination, and cellular complementation","pmids":["26149689"],"confidence":"High","gaps":["Source of the bound ubiquitin in vivo not identified","Mechanism coupling ubiquitin binding to enhanced catalysis unclear"]},{"year":2017,"claim":"Direct arsenite binding to the PHD/RING domain was shown to inhibit FANCL catalysis, providing a chemical mechanism by which an environmental toxin disrupts the FA pathway.","evidence":"In vitro arsenite-binding assay plus cellular FANCD2 monoubiquitination, chromatin recruitment, and clonogenic survival","pmids":["28535027"],"confidence":"Medium","gaps":["Exact cysteines coordinating arsenite not mapped","In vivo relevance to arsenic toxicity not established"]},{"year":2019,"claim":"A small-molecule inhibitor of UBE2T/FANCL catalysis validated the pair as a druggable target for sensitizing cells to crosslinking chemotherapy.","evidence":"High-throughput biochemical screen with in vitro and cellular ubiquitylation assays and carboplatin clonogenic survival","pmids":["31525021"],"confidence":"Medium","gaps":["Binding site of the inhibitor on FANCL not defined","Selectivity over other E3 ligases not characterized"]},{"year":2020,"claim":"Systematic characterization of URD-domain cancer variants separated destabilizing from catalysis-impairing mutations, mapping genotype to FA-pathway dysfunction, while POI frameshift variants linked FANCL mislocalization to human reproductive disease.","evidence":"Thermal shift, FANCD2 interaction, and in vitro ubiquitination with ICL sensitivity for URD variants; immunofluorescence and ligase activity for POI patient variants","pmids":["32420600","32048394"],"confidence":"Medium","gaps":["Causality in POI not proven beyond cellular assays","In vivo consequences of individual URD variants untested"]},{"year":2022,"claim":"A CRISPR knockout combined with catalytic-mutant rescue revealed FANCL has a ubiquitin ligase-independent mitochondrial function supporting Parkin-mediated mitophagy.","evidence":"Mitochondrial fractionation, CRISPR KO, mitophagy assay, and rescue with WT and catalytically dead C307A FANCL","pmids":["35644338"],"confidence":"Medium","gaps":["Molecular role of FANCL at mitochondria undefined","Physiological relevance beyond Parkin-overexpressing cells unknown"]},{"year":2026,"claim":"A catalytic-cysteine knock-in mouse with genetic correction demonstrated that loss of RING E3 ligase activity alone explains all major Fanconi anemia phenotypes, formally separating catalysis from structural roles in disease.","evidence":"CRISPR knock-in mouse, FANCD2 monoubiquitination assay, phenotyping, and CRISPR/prime-editing correction with functional rescue","pmids":["41259745"],"confidence":"High","gaps":["Whether non-catalytic FANCL functions contribute to any residual phenotype not addressed","Translatability of gene correction to human HSCs untested"]},{"year":null,"claim":"How FANCL's ligase-dependent DNA-repair role, its non-proteolytic Wnt/β-catenin signaling activity, and its ligase-independent mitochondrial function are integrated within single cell types remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model linking the three activities","E2 partners for non-FANCD2 substrates incompletely defined","Mitochondrial molecular mechanism unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016874","term_label":"ligase activity","supporting_discovery_ids":[0,5,7,10]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,6,7,10]},{"term_id":"GO:0031386","term_label":"protein tag activity","supporting_discovery_ids":[0,7,10]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[1,19]},{"term_id":"GO:0000228","term_label":"nuclear chromosome","supporting_discovery_ids":[1,6]},{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[14]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[0,6,15]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,7]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[10]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[14]},{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[16,18]}],"complexes":["Fanconi anemia core complex"],"partners":["UBE2T","FANCD2","FANCI","UBE2W","CTNNB1","GGN","AXIN1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9NW38","full_name":"E3 ubiquitin-protein ligase FANCL","aliases":["Fanconi anemia group L protein","Fanconi anemia-associated polypeptide of 43 kDa","FAAP43","RING-type E3 ubiquitin transferase FANCL"],"length_aa":375,"mass_kda":42.9,"function":"Ubiquitin ligase protein that mediates monoubiquitination of FANCD2 in the presence of UBE2T, a key step in the DNA damage pathway (PubMed:12973351, PubMed:16916645, PubMed:17938197, PubMed:19111657, PubMed:24389026). Also mediates monoubiquitination of FANCI (PubMed:19589784). May stimulate the ubiquitin release from UBE2W. May be required for proper primordial germ cell proliferation in the embryonic stage, whereas it is probably not needed for spermatogonial proliferation after birth","subcellular_location":"Cytoplasm; Nucleus","url":"https://www.uniprot.org/uniprotkb/Q9NW38/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/FANCL","classification":"Not Classified","n_dependent_lines":166,"n_total_lines":1208,"dependency_fraction":0.13741721854304637},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"SNX11","stoichiometry":10.0},{"gene":"POLR2D","stoichiometry":0.2},{"gene":"POLR2E","stoichiometry":0.2},{"gene":"SNX7","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/FANCL","total_profiled":1310},"omim":[{"mim_id":"616435","title":"FANCONI ANEMIA, COMPLEMENTATION GROUP T; FANCT","url":"https://www.omim.org/entry/616435"},{"mim_id":"615183","title":"FA CORE COMPLEX-ASSOCIATED PROTEIN 20; FAAP20","url":"https://www.omim.org/entry/615183"},{"mim_id":"614277","title":"UBIQUITIN-CONJUGATING ENZYME E2 W; UBE2W","url":"https://www.omim.org/entry/614277"},{"mim_id":"614083","title":"FANCONI ANEMIA, COMPLEMENTATION GROUP L; FANCL","url":"https://www.omim.org/entry/614083"},{"mim_id":"613984","title":"FANCD2 GENE; FANCD2","url":"https://www.omim.org/entry/613984"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nuclear bodies","reliability":"Approved"},{"location":"Vesicles","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/FANCL"},"hgnc":{"alias_symbol":["FLJ10335","FAAP43","Pog"],"prev_symbol":["PHF9"]},"alphafold":{"accession":"Q9NW38","domains":[{"cath_id":"3.10.110,3.30.457","chopping":"2-102","consensus_level":"high","plddt":88.8698,"start":2,"end":102},{"cath_id":"3.10.110.10","chopping":"109-197","consensus_level":"high","plddt":95.3035,"start":109,"end":197},{"cath_id":"3.10.110.20","chopping":"212-305","consensus_level":"medium","plddt":92.7537,"start":212,"end":305},{"cath_id":"3.30.40.10","chopping":"306-375","consensus_level":"medium","plddt":89.1933,"start":306,"end":375}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NW38","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NW38-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9NW38-F1-predicted_aligned_error_v6.png","plddt_mean":91.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=FANCL","jax_strain_url":"https://www.jax.org/strain/search?query=FANCL"},"sequence":{"accession":"Q9NW38","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9NW38.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9NW38/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9NW38"}},"corpus_meta":[{"pmid":"16469874","id":"PMC_16469874","title":"A prospective study of the natural history of transient leukemia (TL) in neonates with Down syndrome (DS): Children's Oncology Group (COG) study POG-9481.","date":"2006","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/16469874","citation_count":199,"is_preprint":false},{"pmid":"20661450","id":"PMC_20661450","title":"Sex reversal in zebrafish fancl mutants is caused by Tp53-mediated germ cell apoptosis.","date":"2010","source":"PLoS genetics","url":"https://pubmed.ncbi.nlm.nih.gov/20661450","citation_count":169,"is_preprint":false},{"pmid":"19111657","id":"PMC_19111657","title":"Mechanistic insight into site-restricted monoubiquitination of FANCD2 by Ube2t, FANCL, and FANCI.","date":"2008","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/19111657","citation_count":158,"is_preprint":false},{"pmid":"21474675","id":"PMC_21474675","title":"Effectiveness of high-dose methotrexate in T-cell lymphoblastic leukemia and advanced-stage lymphoblastic lymphoma: a randomized study by the Children's Oncology Group (POG 9404).","date":"2011","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/21474675","citation_count":135,"is_preprint":false},{"pmid":"12417526","id":"PMC_12417526","title":"A novel gene, Pog, is necessary for primordial germ cell proliferation in the mouse and underlies the germ cell deficient mutation, gcd.","date":"2002","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/12417526","citation_count":105,"is_preprint":false},{"pmid":"14712086","id":"PMC_14712086","title":"FANCL replaces BRCA1 as the likely ubiquitin ligase responsible for FANCD2 monoubiquitination.","date":"2004","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/14712086","citation_count":80,"is_preprint":false},{"pmid":"19589784","id":"PMC_19589784","title":"FANCI binds branched DNA and is monoubiquitinated by UBE2T-FANCL.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19589784","citation_count":72,"is_preprint":false},{"pmid":"24389026","id":"PMC_24389026","title":"Structure of the human FANCL RING-Ube2T complex reveals determinants of cognate E3-E2 selection.","date":"2014","source":"Structure (London, England : 1993)","url":"https://pubmed.ncbi.nlm.nih.gov/24389026","citation_count":66,"is_preprint":false},{"pmid":"18704922","id":"PMC_18704922","title":"Outcomes of the POG 9340/9341/9342 trials for children with high-risk neuroblastoma: a report from the Children's Oncology Group.","date":"2008","source":"Pediatric blood & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/18704922","citation_count":63,"is_preprint":false},{"pmid":"20154706","id":"PMC_20154706","title":"The structure of the catalytic subunit FANCL of the Fanconi anemia core complex.","date":"2010","source":"Nature structural & molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/20154706","citation_count":59,"is_preprint":false},{"pmid":"9065717","id":"PMC_9065717","title":"Therapeutic trial for infant acute lymphoblastic leukemia: the Pediatric Oncology Group experience (POG 8493).","date":"1997","source":"Journal of pediatric hematology/oncology","url":"https://pubmed.ncbi.nlm.nih.gov/9065717","citation_count":45,"is_preprint":false},{"pmid":"16474167","id":"PMC_16474167","title":"The WD40 repeats of FANCL are required for Fanconi anemia core complex assembly.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16474167","citation_count":43,"is_preprint":false},{"pmid":"21775430","id":"PMC_21775430","title":"Structural analysis of human FANCL, the E3 ligase in the Fanconi anemia pathway.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21775430","citation_count":41,"is_preprint":false},{"pmid":"32048394","id":"PMC_32048394","title":"FANCL gene mutations in premature ovarian insufficiency.","date":"2020","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/32048394","citation_count":40,"is_preprint":false},{"pmid":"11150431","id":"PMC_11150431","title":"The effect of cisplatin dose and surgical resection in children with malignant germ cell tumors at the sacrococcygeal region: a pediatric intergroup trial (POG 9049/CCG 8882).","date":"2001","source":"Journal of pediatric surgery","url":"https://pubmed.ncbi.nlm.nih.gov/11150431","citation_count":39,"is_preprint":false},{"pmid":"12574169","id":"PMC_12574169","title":"Mouse GGN1 and GGN3, two germ cell-specific proteins from the single gene Ggn, interact with mouse POG and play a role in spermatogenesis.","date":"2003","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12574169","citation_count":34,"is_preprint":false},{"pmid":"12606378","id":"PMC_12606378","title":"Late onset of spermatogenesis and gain of fertility in POG-deficient mice indicate that POG is not necessary for the proliferation of spermatogonia.","date":"2003","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/12606378","citation_count":33,"is_preprint":false},{"pmid":"16860002","id":"PMC_16860002","title":"Drosophila homologs of FANCD2 and FANCL function in DNA repair.","date":"2006","source":"DNA repair","url":"https://pubmed.ncbi.nlm.nih.gov/16860002","citation_count":32,"is_preprint":false},{"pmid":"18607065","id":"PMC_18607065","title":"Hypermethylation of the FANCC and FANCL promoter regions in sporadic acute leukaemia.","date":"2008","source":"Cellular oncology : the official journal of the International Society for Cellular Oncology","url":"https://pubmed.ncbi.nlm.nih.gov/18607065","citation_count":32,"is_preprint":false},{"pmid":"22653977","id":"PMC_22653977","title":"FANCL ubiquitinates β-catenin and enhances its nuclear function.","date":"2012","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/22653977","citation_count":31,"is_preprint":false},{"pmid":"17352736","id":"PMC_17352736","title":"A requirement of FancL and FancD2 monoubiquitination in DNA repair.","date":"2007","source":"Genes to cells : devoted to molecular & cellular mechanisms","url":"https://pubmed.ncbi.nlm.nih.gov/17352736","citation_count":29,"is_preprint":false},{"pmid":"31525021","id":"PMC_31525021","title":"Small-Molecule Inhibition of UBE2T/FANCL-Mediated Ubiquitylation in the Fanconi Anemia Pathway.","date":"2019","source":"ACS chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/31525021","citation_count":28,"is_preprint":false},{"pmid":"19737859","id":"PMC_19737859","title":"Mutational analysis of FANCL, FANCM and the recently identified FANCI suggests that among the 13 known Fanconi Anemia genes, only FANCD1/BRCA2 plays a major role in high-risk breast cancer predisposition.","date":"2009","source":"Carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/19737859","citation_count":28,"is_preprint":false},{"pmid":"25754594","id":"PMC_25754594","title":"Loss-of-Function FANCL Mutations Associate with Severe Fanconi Anemia Overlapping the VACTERL Association.","date":"2015","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/25754594","citation_count":28,"is_preprint":false},{"pmid":"21229326","id":"PMC_21229326","title":"UBE2W interacts with FANCL and regulates the monoubiquitination of Fanconi anemia protein FANCD2.","date":"2010","source":"Molecules and cells","url":"https://pubmed.ncbi.nlm.nih.gov/21229326","citation_count":26,"is_preprint":false},{"pmid":"26149689","id":"PMC_26149689","title":"The Fanconi Anemia DNA Repair Pathway Is Regulated by an Interaction between Ubiquitin and the E2-like Fold Domain of FANCL.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26149689","citation_count":26,"is_preprint":false},{"pmid":"17106252","id":"PMC_17106252","title":"Altered expression of FANCL confers mitomycin C sensitivity in Calu-6 lung cancer cells.","date":"2006","source":"Cancer biology & therapy","url":"https://pubmed.ncbi.nlm.nih.gov/17106252","citation_count":26,"is_preprint":false},{"pmid":"19405097","id":"PMC_19405097","title":"Identification and characterization of mutations in FANCL gene: a second case of Fanconi anemia belonging to FA-L complementation group.","date":"2009","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/19405097","citation_count":24,"is_preprint":false},{"pmid":"28535027","id":"PMC_28535027","title":"Arsenite Binds to the RING Finger Domain of FANCL E3 Ubiquitin Ligase and Inhibits DNA Interstrand Crosslink Repair.","date":"2017","source":"ACS chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/28535027","citation_count":22,"is_preprint":false},{"pmid":"14565163","id":"PMC_14565163","title":"Phase 2 study of idarubicin in pediatric brain tumors: Pediatric Oncology Group study POG 9237.","date":"2003","source":"Neuro-oncology","url":"https://pubmed.ncbi.nlm.nih.gov/14565163","citation_count":21,"is_preprint":false},{"pmid":"16007607","id":"PMC_16007607","title":"Antimetabolite-based therapy in childhood T-cell acute lymphoblastic leukemia: a report of POG study 9296.","date":"2006","source":"Pediatric blood & cancer","url":"https://pubmed.ncbi.nlm.nih.gov/16007607","citation_count":17,"is_preprint":false},{"pmid":"8119152","id":"PMC_8119152","title":"A new monoclonal antibody (POG-1) detects a differentiation antigen of porcine granulosa and thecal cells and indicates heterogeneity of thecal-stromal cells.","date":"1994","source":"Endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/8119152","citation_count":14,"is_preprint":false},{"pmid":"8039165","id":"PMC_8039165","title":"Presenting characteristics of trisomy 8 as the primary cytogenetic abnormality associated with childhood acute lymphoblastic leukemia. A Pediatric Oncology Group (POG) Study (8600/8493).","date":"1994","source":"Cancer genetics and cytogenetics","url":"https://pubmed.ncbi.nlm.nih.gov/8039165","citation_count":12,"is_preprint":false},{"pmid":"35644338","id":"PMC_35644338","title":"FANCL supports Parkin-mediated mitophagy in a ubiquitin ligase-independent manner.","date":"2022","source":"Biochimica et biophysica acta. Molecular basis of disease","url":"https://pubmed.ncbi.nlm.nih.gov/35644338","citation_count":11,"is_preprint":false},{"pmid":"21543111","id":"PMC_21543111","title":"Evaluation of Fanconi anaemia genes FANCA, FANCC and FANCL in cervical cancer susceptibility.","date":"2011","source":"Gynecologic oncology","url":"https://pubmed.ncbi.nlm.nih.gov/21543111","citation_count":11,"is_preprint":false},{"pmid":"31513304","id":"PMC_31513304","title":"A founder variant in the South Asian population leads to a high prevalence of FANCL Fanconi anemia cases in India.","date":"2019","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/31513304","citation_count":10,"is_preprint":false},{"pmid":"23783032","id":"PMC_23783032","title":"The PI3K/Akt1 pathway enhances steady-state levels of FANCL.","date":"2013","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/23783032","citation_count":9,"is_preprint":false},{"pmid":"22918243","id":"PMC_22918243","title":"Switch of FANCL, a key FA-BRCA component, between tumor suppressor and promoter by alternative splicing.","date":"2012","source":"Cell cycle (Georgetown, Tex.)","url":"https://pubmed.ncbi.nlm.nih.gov/22918243","citation_count":9,"is_preprint":false},{"pmid":"32420600","id":"PMC_32420600","title":"Characterization of FANCL variants observed in patient cancer cells.","date":"2020","source":"Bioscience reports","url":"https://pubmed.ncbi.nlm.nih.gov/32420600","citation_count":8,"is_preprint":false},{"pmid":"28419882","id":"PMC_28419882","title":"Novel homozygous FANCL mutation and somatic heterozygous SETBP1 mutation in a Chinese girl with Fanconi Anemia.","date":"2017","source":"European journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/28419882","citation_count":8,"is_preprint":false},{"pmid":"23887024","id":"PMC_23887024","title":"Treatment of relapsed precursor-B acute lymphoblastic leukemia with intensive chemotherapy: POG (Pediatric Oncology Group) study 9411 (SIMAL 9).","date":"2013","source":"Journal of pediatric hematology/oncology","url":"https://pubmed.ncbi.nlm.nih.gov/23887024","citation_count":8,"is_preprint":false},{"pmid":"34289691","id":"PMC_34289691","title":"Quantitative Proteomics Reveals a Novel Role of the E3 Ubiquitin-Protein Ligase FANCL in the Activation of the Innate Immune Response through Regulation of TBK1 Phosphorylation during Peste des Petits Ruminants Virus Infection.","date":"2021","source":"Journal of proteome research","url":"https://pubmed.ncbi.nlm.nih.gov/34289691","citation_count":7,"is_preprint":false},{"pmid":"40479584","id":"PMC_40479584","title":"Deficient FANCL Predisposes to Endothelial Damage: A New Therapeutic Target for Pulmonary Hypertension.","date":"2025","source":"American journal of respiratory and critical care medicine","url":"https://pubmed.ncbi.nlm.nih.gov/40479584","citation_count":3,"is_preprint":false},{"pmid":"16201245","id":"PMC_16201245","title":"[Functions of FANCL in primordial germ cell formation and Fanconi anemia].","date":"2005","source":"Yi chuan xue bao = Acta genetica Sinica","url":"https://pubmed.ncbi.nlm.nih.gov/16201245","citation_count":3,"is_preprint":false},{"pmid":"33054796","id":"PMC_33054796","title":"Poly(POG)n loaded with recombinant human bone morphogenetic protein-2 accelerates new bone formation in a critical-sized bone defect mouse model.","date":"2020","source":"Journal of orthopaedic surgery and research","url":"https://pubmed.ncbi.nlm.nih.gov/33054796","citation_count":3,"is_preprint":false},{"pmid":"22528643","id":"PMC_22528643","title":"No evidence for translation of pog, a predicted overlapping gene of Solenopsis invicta virus 1.","date":"2012","source":"Virus genes","url":"https://pubmed.ncbi.nlm.nih.gov/22528643","citation_count":2,"is_preprint":false},{"pmid":"8892109","id":"PMC_8892109","title":"Monoclonal antibody PHF-9 recognizes phosphorylated serine 404 of tau protein and labels paired helical filaments.","date":"1996","source":"Journal of neuroscience research","url":"https://pubmed.ncbi.nlm.nih.gov/8892109","citation_count":2,"is_preprint":false},{"pmid":"37327301","id":"PMC_37327301","title":"An acquired BMF with FANCL gene heterozygous mutation: Case report.","date":"2023","source":"Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/37327301","citation_count":0,"is_preprint":false},{"pmid":"41259745","id":"PMC_41259745","title":"Fancl-mutant mice reveal central role of monoubiquitination in Fanconi anemia and a model for therapeutic gene editing.","date":"2026","source":"Blood advances","url":"https://pubmed.ncbi.nlm.nih.gov/41259745","citation_count":0,"is_preprint":false},{"pmid":"41306722","id":"PMC_41306722","title":"Piperine Targets the FANCL/UBE2T Complex to Inhibit the FA Pathway and Sensitize Bladder Cancer to Cisplatin.","date":"2025","source":"Dose-response : a publication of International Hormesis Society","url":"https://pubmed.ncbi.nlm.nih.gov/41306722","citation_count":0,"is_preprint":false},{"pmid":"41425456","id":"PMC_41425456","title":"Ginsenoside Rh2 Suppresses the Fanconi Anemia Pathway by Inhibiting NF-κB-Mediated FANCL Transcription in Bladder Cancer.","date":"2025","source":"Dose-response : a publication of International Hormesis Society","url":"https://pubmed.ncbi.nlm.nih.gov/41425456","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.26.672363","title":"Chromatin signalling pathways and FANCE amplification affect ATR inhibitor sensitivity in metastatic breast cancer","date":"2025-08-31","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.26.672363","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.27.25324819","title":"Normative serum cortisol levels in second and third trimesters and their associated factors: A prospective cohort study from Sri Lanka","date":"2025-03-28","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.27.25324819","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.02.12.637569","title":"Overcoming Cisplatin Resistance in TP53-null Colon Cancer Organoids","date":"2025-02-17","source":"bioRxiv","url":"https://doi.org/10.1101/2025.02.12.637569","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":28008,"output_tokens":6075,"usd":0.087574,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":14651,"output_tokens":5824,"usd":0.109427,"stage2_stop_reason":"end_turn"},"total_usd":0.197001,"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\": 2008,\n      \"finding\": \"FANCL acts as an E3 ubiquitin ligase that, together with the E2-conjugating enzyme Ube2t, is sufficient to monoubiquitinate FANCD2 in a minimal reconstituted system. A conserved RWD-like domain in FANCL stimulates monoubiquitination, and addition of FANCI enhances the reaction and restricts it to the correct in vivo lysine residue on FANCD2 (K561).\",\n      \"method\": \"In vitro reconstitution of monoubiquitination with purified Ube2t and FANCL; addition of FANCI to assess site restriction\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with purified components, domain-level dissection, replicated by multiple subsequent studies\",\n      \"pmids\": [\"19111657\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"FANCL (PHF9), but not BRCA1, is the likely E3 ubiquitin ligase responsible for FANCD2 monoubiquitination. In FANCL-mutant cells, monoubiquitinated FANCD2 is absent from chromatin and nuclear matrix fractions, whereas non-ubiquitinated FANCD2 resides in the soluble fraction, demonstrating that FANCL-dependent monoubiquitination is required for FANCD2 chromatin association.\",\n      \"method\": \"Subcellular fractionation of FANCL-mutant vs. BRCA1-mutant cell lines; evolutionary co-existence analysis of FANCL and FANCD2\",\n      \"journal\": \"Cell cycle (Georgetown, Tex.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — fractionation with mutant cell lines plus evolutionary analysis; single lab, two orthogonal approaches\",\n      \"pmids\": [\"14712086\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Crystal structure of FANCL at 3.2 Å reveals three domains: an N-terminal E2-like fold (ELF domain), a novel double-RWD (DRWD) domain, and a C-terminal RING domain. Binding assays show the DRWD domain (not ELF) is responsible for substrate (FANCD2/FANCI) binding, while the RING domain mediates E2 (Ube2T) interaction.\",\n      \"method\": \"X-ray crystallography at 3.2 Å; domain-deletion binding assays\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — atomic-resolution crystal structure combined with functional binding assays in a single rigorous study\",\n      \"pmids\": [\"20154706\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Crystal structure of the FANCL RING domain in complex with Ube2T reveals an extensive network of specific electrostatic and hydrophobic interactions beyond the generic E3–E2 interface, and mutagenesis shows these specific interactions are required for selective recruitment of Ube2T over other E2 enzymes by FANCL.\",\n      \"method\": \"X-ray crystallography of FANCL RING–Ube2T complex; site-directed mutagenesis of interface residues; E2 selectivity assays\",\n      \"journal\": \"Structure (London, England : 1993)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — atomic structure plus mutagenesis establishing functional determinants of E2 selectivity in one study\",\n      \"pmids\": [\"24389026\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Structure of the central (DRWD/URD) domain of human FANCL confirms conservation with Drosophila FANCL. Mutational analysis identifies residues in the DRWD domain required for binding FANCD2 and FANCI substrates, and a separate region required for Ube2T binding.\",\n      \"method\": \"X-ray crystallography of central domain; mutagenesis; binding assays with FANCD2, FANCI, and Ube2T\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure with systematic mutagenesis and interaction assays defining functional residues\",\n      \"pmids\": [\"21775430\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"The WD40 repeats (not the PHD/RING domain) of FANCL are required for interaction with other FA core complex subunits. The PHD domain is dispensable for core complex incorporation but is required for FANCD2 monoubiquitination; a conserved tryptophan in the PHD analogous to the c-CBL RING finger is required for in vitro auto-ubiquitination and in vivo FANCD2 monoubiquitination.\",\n      \"method\": \"Domain-deletion and point-mutation constructs expressed in FANCL-deficient cells; co-immunoprecipitation; in vitro ubiquitination assay; MMC resistance complementation\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal domain dissection with multiple orthogonal functional readouts (co-IP, in vitro ubiquitination, MMC resistance)\",\n      \"pmids\": [\"16474167\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"FANCL physically interacts with FANCD2 via its PHD domain (co-immunoprecipitation in 293T cells and yeast two-hybrid). FANCL is required for FANCD2 monoubiquitination and focus formation in DT40 cells, and loss of FANCL (or FANCD2 monoubiquitination) causes quantitatively identical defects in homologous recombination repair of I-SceI-induced chromosomal breaks.\",\n      \"method\": \"Yeast two-hybrid; co-immunoprecipitation; FANCL gene disruption in DT40 cells; I-SceI HR repair assay; focus formation immunoassay\",\n      \"journal\": \"Genes to cells : devoted to molecular & cellular mechanisms\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal interactions plus genetic epistasis placing FANCL upstream of FANCD2 monoubiquitination in HR repair; replicated in avian and human cell systems\",\n      \"pmids\": [\"17352736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The UBE2T–FANCL pair can monoubiquitinate FANCI on Lys-523 in vitro. FANCI binds branched DNA structures through its C-terminal fragment, a binding activity that likely positions it as a substrate.\",\n      \"method\": \"In vitro ubiquitination assay with purified UBE2T and FANCL; DNA binding assay with branched DNA substrates\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution demonstrating FANCI as a direct FANCL/UBE2T substrate; single lab, multiple biochemical methods\",\n      \"pmids\": [\"19589784\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"UBE2W interacts with the PHD domain of FANCL (the PHD domain is necessary and sufficient for this interaction) and catalyzes monoubiquitination of the FANCL PHD domain in vitro. UBE2W overexpression promotes FANCD2 monoubiquitination in cells, and UBE2W knockdown reduces UV-induced (but not MMC-induced) FANCD2 monoubiquitination, indicating UBE2W regulates FANCD2 monoubiquitination through FANCL by a mechanism distinct from UBE2T.\",\n      \"method\": \"Co-immunoprecipitation; domain-deletion mapping; in vitro ubiquitination assay; siRNA knockdown with FANCD2 monoubiquitination readout\",\n      \"journal\": \"Molecules and cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP domain mapping plus in vitro ubiquitination and cellular knockdown; single lab, multiple complementary methods\",\n      \"pmids\": [\"21229326\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"The N-terminal ELF domain of FANCL mediates a non-covalent interaction with ubiquitin via the canonical Ile44 patch on ubiquitin. This interaction is not required for FANCD2 monoubiquitination in vitro, nor for core complex recognition or Ube2T binding, but is required for efficient DNA damage-induced FANCD2 monoubiquitination in vertebrate cells, indicating a regulatory in vivo function for ubiquitin binding by the ELF domain.\",\n      \"method\": \"NMR/binding assays for ELF–ubiquitin interaction; mutagenesis of ubiquitin Ile44 patch and corresponding FANCL patch; in vitro ubiquitination assay; cellular complementation assay for damage-induced FANCD2 monoubiquitination\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — structural/biophysical interaction mapping plus mutagenesis and cellular functional validation; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"26149689\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"FANCL ubiquitinates β-catenin with atypical lysine-11 ubiquitin chain extension (non-proteolytic), enhancing β-catenin nuclear activity and transcription of Wnt targets c-Myc and Cyclin D1. FANCL-deficient cells show diminished β-catenin activation, and suppression of FANCL in human CD34+ stem/progenitor cells reduces β-catenin-active cells and inhibits multilineage progenitor expansion.\",\n      \"method\": \"Co-immunoprecipitation; in vitro ubiquitination assay; LEF/TCF reporter assay; immunofluorescence; FANCL knockdown in human CD34+ cells with colony/progenitor readout\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro ubiquitination plus reporter assay and primary stem cell functional readout; single lab, multiple methods\",\n      \"pmids\": [\"22653977\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"FANCL protein is constitutively targeted for proteasomal degradation via K48-linked polyubiquitination. The ELF (E2-like fold) domain may direct this polyubiquitination. FANCL is stabilized in a complex with axin1 when GSK-3β is overexpressed, and constitutively active Akt (myristoylated) increases FANCL steady-state levels by reducing K48-linked polyubiquitination. Phosphorylated (acidic) forms of FANCL are not subject to polyubiquitination.\",\n      \"method\": \"Proteasome inhibitor treatment; K48-linkage-specific ubiquitination assay; N-terminal deletion constructs; co-immunoprecipitation with axin1/GSK-3β; 2D-PAGE phospho-FANCL analysis; constitutively active Akt expression\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple biochemical approaches in single lab establishing a post-translational stability mechanism\",\n      \"pmids\": [\"23783032\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Arsenite (As3+) binds directly to the PHD/RING finger domain of FANCL both in vitro and in cells. This binding compromises FANCL-mediated FANCD2 ubiquitination in cells, reduces FANCD2 chromatin recruitment to DNA damage sites, and renders cells more sensitive to DNA interstrand cross-linking agents.\",\n      \"method\": \"In vitro binding assay (recombinant FANCL PHD/RING + arsenite); cellular As3+ treatment with FANCD2 monoubiquitination and chromatin recruitment readout; clonogenic survival assay\",\n      \"journal\": \"ACS chemical biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding assay plus cellular functional readouts; single lab, multiple complementary methods\",\n      \"pmids\": [\"28535027\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"A small-molecule inhibitor identified by high-throughput screening inhibits UBE2T/FANCL-mediated FANCD2 monoubiquitylation and sensitizes cells to the DNA cross-linking agent carboplatin, validating the UBE2T–FANCL catalytic pair as a druggable target in the FA pathway.\",\n      \"method\": \"High-throughput biochemical screen; in vitro ubiquitylation assay; cellular FANCD2 monoubiquitylation assay; clonogenic survival with carboplatin\",\n      \"journal\": \"ACS chemical biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — biochemical screen with cellular validation; single lab, multiple orthogonal readouts\",\n      \"pmids\": [\"31525021\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"FANCL protein localizes to mitochondria (in both basal and mitochondrial stress conditions), and its ubiquitin ligase activity is not required for this mitochondrial localization. CRISPR/Cas9 knockout of FANCL in parkin-overexpressing HeLa cells impairs clearance of damaged mitochondria (mitophagy) upon oligomycin/antimycin treatment; this defect is rescued by reintroduction of either wild-type FANCL or the catalytically dead FANCL(C307A) mutant, demonstrating a ubiquitin ligase-independent role in supporting Parkin-mediated mitophagy.\",\n      \"method\": \"Subcellular fractionation/mitochondrial localization; CRISPR/Cas9 KO; mitophagy assay (mitochondrial clearance upon OA stress); complementation with WT and C307A catalytic mutant\",\n      \"journal\": \"Biochimica et biophysica acta. Molecular basis of disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO with specific phenotypic readout and catalytic-mutant rescue demonstrating ligase-independent function; single lab\",\n      \"pmids\": [\"35644338\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"In Drosophila, FANCL is necessary for monoubiquitination of FANCD2, and epistasis analysis places FANCL upstream of FANCD2 in a linear DNA repair pathway. Knockdown of either FANCL or FANCD2 confers hypersensitivity to cross-linking agents.\",\n      \"method\": \"RNAi knockdown in Drosophila; cross-linking agent sensitivity assay; FANCD2 monoubiquitination Western blot; genetic epistasis\",\n      \"journal\": \"DNA repair\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis in Drosophila model with functional readouts; single study but ortholog-consistent with mammalian data\",\n      \"pmids\": [\"16860002\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Mouse Pog (the ortholog of FANCL) is necessary for primordial germ cell (PGC) proliferation between E9.5 and E10.25 dpc. Deletion of Pog causes the germ-cell-deficient (gcd) phenotype with reduced PGC numbers and adult sterility; the proliferation defect rather than aberrant migration is responsible.\",\n      \"method\": \"Targeted Pog knockout mice; PGC counting at multiple developmental time points; comparison with gcd insertional mutant\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mouse KO with defined cellular phenotype; single lab but clear loss-of-function result\",\n      \"pmids\": [\"12417526\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"POG (FANCL ortholog) interacts with GGN1 and GGN3 (gametogenetin isoforms) via yeast two-hybrid and co-expression in HeLa cells. Co-expression of POG with GGN1 or GGN3 relocalizes POG to the perinuclear region or nucleoli, respectively, and Pog-deficient mice show impaired meiosis during spermatogenesis.\",\n      \"method\": \"Yeast two-hybrid; co-expression in HeLa cells with localization readout; Pog-knockout mouse spermatogenesis analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — yeast two-hybrid interaction plus cellular co-localization and mouse KO phenotype; single lab, consistent across methods\",\n      \"pmids\": [\"12574169\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"In zebrafish, fancl is expressed in developing germ cells at the critical time of sexual fate determination. Loss of fancl causes Tp53-mediated germ cell apoptosis (demonstrated by caspase-3 immunoassay), compromises oocyte survival through meiosis, and results in female-to-male sex reversal. Introduction of a tp53 mutation into fancl mutants rescues sex reversal by reducing germ cell apoptosis.\",\n      \"method\": \"fancl mutant zebrafish; caspase-3 immunoassay; cyp19a1a and amh expression analysis; tp53;fancl double mutant genetic epistasis; fertility assay\",\n      \"journal\": \"PLoS genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (expression analysis, apoptosis assay, double-mutant epistasis) in zebrafish model establishing mechanism; well-controlled study\",\n      \"pmids\": [\"20661450\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Two heterozygous frameshift mutations in FANCL (c.1048_1051delGTCT and c.739dupA) identified in POI patients cause cytoplasmic retention of mutant FANCL protein (whereas wild-type FANCL is nuclear), impaired ubiquitin-ligase activity, and compromised DNA repair after mitomycin C treatment.\",\n      \"method\": \"Subcellular localization of mutant vs. WT FANCL by immunofluorescence; in vitro ubiquitin ligase activity assay; MMC DNA repair assay in patient-derived cells\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization plus biochemical activity assays on patient variants; single lab, multiple methods\",\n      \"pmids\": [\"32048394\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"A murine FanclTATΔ allele removing the catalytic cysteine in the RING domain generates a core complex that retains structural integrity but lacks FANCD2 monoubiquitination activity. Homozygous mice phenocopy human FA (infertility, craniofacial anomalies, DNA damage hypersensitivity, progressive HSC loss). CRISPR-Cas9 or prime editing correction of the mutation restores FANCD2 monoubiquitination and DNA damage resistance in myeloid cells, demonstrating that loss of RING E3 ligase activity alone explains all major FA phenotypes.\",\n      \"method\": \"CRISPR knock-in mouse model; biochemical FANCD2 monoubiquitination assay; mouse phenotyping; CRISPR-Cas9 and prime editing correction with functional rescue\",\n      \"journal\": \"Blood advances\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — catalytic-residue knock-in plus genetic correction with multiple orthogonal phenotypic and biochemical readouts; comprehensive mechanistic validation\",\n      \"pmids\": [\"41259745\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Analysis of 17 FANCL URD-domain variants from patient cancer cells shows that mutations I136V, L154S, W212A, L214A, R221W, R221C, and V287G destabilize FANCL, while E217K, T224K, M247V, and the hydrophobic patch mutants (L248A, F252A, L254A, I265A) impair catalytic function without destabilizing the fold. N270K and E289Q specifically destabilize the C-terminal helices of the URD domain. These functional defects correlate with cellular sensitivity to an interstrand cross-linking agent.\",\n      \"method\": \"Recombinant expression; thermal shift assay; FANCD2 interaction assay; in vitro ubiquitination assay; cellular ICL sensitivity assay\",\n      \"journal\": \"Bioscience reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — systematic biochemical and structural characterization with cellular validation; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"32420600\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"FANCL is the RING-type E3 ubiquitin ligase subunit of the Fanconi anemia core complex; its three-domain architecture (ELF, DRWD/URD, RING) assigns distinct roles—the RING domain selectively recruits the E2 enzyme UBE2T, the central DRWD domain recognizes the FANCD2/FANCI substrate dimer, and the ELF domain binds free ubiquitin to promote efficient damage-induced monoubiquitination in vivo. Together with UBE2T, FANCL monoubiquitinates FANCD2 and FANCI in a reaction stimulated by FANCI and restricted to the correct lysine, targeting the ID complex to chromatin for homologous recombination repair of interstrand crosslinks; FANCL also ubiquitinates β-catenin with K11-linked chains to enhance Wnt signaling in hematopoietic stem cells, supports Parkin-mediated mitophagy in a ligase-independent manner, and is required for primordial germ cell proliferation and oocyte survival through meiosis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"FANCL is the catalytic RING-type E3 ubiquitin ligase subunit of the Fanconi anemia core complex, partnering with the E2 enzyme UBE2T to monoubiquitinate FANCD2 and FANCI and thereby drive homologous-recombination repair of DNA interstrand crosslinks [#0, #6]. Its crystal structure resolves a tripartite architecture in which the central DRWD/URD domain binds the FANCD2/FANCI substrate dimer while the C-terminal RING domain mediates E2 recruitment, and an extensive electrostatic/hydrophobic RING\\u2013UBE2T interface confers selective recruitment of UBE2T over other E2 enzymes [#2, #3]. Reconstitution shows FANCL and UBE2T are sufficient to monoubiquitinate FANCD2, with FANCI both stimulating the reaction and restricting modification to the correct lysine (K561 on FANCD2; K523 on FANCI) [#0, #7]; the N-terminal ELF domain additionally binds free ubiquitin via the Ile44 patch to promote efficient damage-induced FANCD2 monoubiquitination in cells [#9]. FANCL-dependent monoubiquitination is required for FANCD2 chromatin and nuclear-matrix association and for HR repair of induced chromosomal breaks, an epistatic relationship conserved from Drosophila to vertebrates [#1, #6, #15]. A catalytic-cysteine knock-in mouse establishes that loss of RING E3 ligase activity alone reproduces all major Fanconi anemia phenotypes, and FANCL variants causing protein destabilization or cytoplasmic mislocalization underlie premature ovarian insufficiency [#20, #19]. Beyond DNA repair, FANCL extends K11-linked non-proteolytic ubiquitin chains on \\u03b2-catenin to enhance Wnt target transcription in hematopoietic stem/progenitor cells [#10], supports Parkin-mediated mitophagy through a ubiquitin ligase-independent mitochondrial function [#14], and is required for primordial germ cell proliferation and oocyte survival through meiosis [#16, #18].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Before its biochemical role was known, the FANCL ortholog was shown to be developmentally essential, establishing a germ-cell function distinct from any later-defined enzymatic activity.\",\n      \"evidence\": \"Targeted Pog knockout mice with primordial germ cell counting across developmental time points\",\n      \"pmids\": [\"12417526\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism of the proliferation defect not defined\", \"No link to ubiquitination established at this stage\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Identification of GGN1/GGN3 as POG interactors that relocalize the protein addressed where and with what partners FANCL acts during gametogenesis.\",\n      \"evidence\": \"Yeast two-hybrid and HeLa co-expression with localization readout, plus Pog-knockout spermatogenesis analysis\",\n      \"pmids\": [\"12574169\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of GGN binding for ligase activity unknown\", \"Interactions not validated in germ cells in vivo\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"The question of which factor monoubiquitinates FANCD2 was narrowed to FANCL, linking its activity to FANCD2 chromatin localization.\",\n      \"evidence\": \"Subcellular fractionation of FANCL- vs BRCA1-mutant cells plus evolutionary co-existence analysis\",\n      \"pmids\": [\"14712086\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No reconstitution showing direct ligase activity\", \"E2 partner not identified\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Domain dissection separated FANCL's structural role in the core complex from its catalytic role, and Drosophila epistasis placed FANCL upstream of FANCD2 in a linear repair pathway.\",\n      \"evidence\": \"Domain-deletion/point mutants in FANCL-deficient cells with co-IP, in vitro ubiquitination, MMC complementation; RNAi epistasis in Drosophila\",\n      \"pmids\": [\"16474167\", \"16860002\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"E2 enzyme identity unresolved\", \"Atomic basis of substrate vs core-complex binding not defined\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Genetic and physical evidence established FANCL as required for FANCD2 monoubiquitination, focus formation, and HR repair, quantitatively coupling its activity to recombination outcome.\",\n      \"evidence\": \"Yeast two-hybrid, co-IP, FANCL disruption in DT40 cells, I-SceI HR assay, focus formation\",\n      \"pmids\": [\"17352736\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Reconstitution with defined components still lacking\", \"Site specificity of modification unaddressed\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Minimal reconstitution proved FANCL plus UBE2T are sufficient to monoubiquitinate FANCD2, and that FANCI confers site specificity \\u2014 defining the core catalytic logic of the FA pathway.\",\n      \"evidence\": \"In vitro reconstitution with purified UBE2T and FANCL; FANCI addition to assess K561 site restriction\",\n      \"pmids\": [\"19111657\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of E2 and substrate selection not yet resolved\", \"Mechanism of FANCI-driven site restriction not defined\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"FANCI was shown to be a direct second substrate of the UBE2T\\u2013FANCL pair, broadening the enzyme's targets within the ID complex.\",\n      \"evidence\": \"In vitro ubiquitination with purified UBE2T/FANCL on FANCI K523; branched DNA binding assay\",\n      \"pmids\": [\"19589784\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Order/coordination of FANCD2 vs FANCI modification in vivo unclear\", \"Role of DNA binding in substrate positioning not directly tested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"The crystal structure assigned distinct molecular functions to FANCL's three domains, defining DRWD as the substrate-binding module and RING as the E2-interaction module.\",\n      \"evidence\": \"X-ray crystallography at 3.2 \\u00c5 with domain-deletion binding assays\",\n      \"pmids\": [\"20154706\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Determinants of E2 selectivity not resolved at residue level\", \"Role of ELF domain undefined\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"A non-canonical E2 (UBE2W) acting on FANCL's PHD domain was found to regulate FANCD2 monoubiquitination via a UV-specific route distinct from UBE2T.\",\n      \"evidence\": \"Co-IP domain mapping, in vitro ubiquitination, and siRNA knockdown with FANCD2 readout\",\n      \"pmids\": [\"21229326\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Physiological significance of FANCL PHD monoubiquitination unclear\", \"Single-lab finding not independently reproduced\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Zebrafish work revealed FANCL safeguards germ cell survival through meiosis by suppressing Tp53-dependent apoptosis, mechanistically explaining its sex-determination role.\",\n      \"evidence\": \"fancl mutant zebrafish, caspase-3 assay, tp53;fancl double-mutant epistasis, fertility assay\",\n      \"pmids\": [\"20661450\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether germ-cell role depends on ligase activity not tested here\", \"Connection to ICL repair in germ cells not established\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Structure and mutagenesis of the central DRWD/URD domain pinpointed the residues for FANCD2/FANCI binding versus UBE2T binding, refining the substrate-recognition map.\",\n      \"evidence\": \"X-ray crystallography of the central domain with mutagenesis and binding assays\",\n      \"pmids\": [\"21775430\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Dynamics of substrate handoff to the RING-bound E2 unresolved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"FANCL was shown to extend atypical K11-linked, non-proteolytic chains on \\u03b2-catenin, defining a DNA-repair-independent role in Wnt signaling and HSC progenitor expansion.\",\n      \"evidence\": \"Co-IP, in vitro ubiquitination, LEF/TCF reporter, and FANCL knockdown in CD34+ cells\",\n      \"pmids\": [\"22653977\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"E2 partner for \\u03b2-catenin chains not identified\", \"In vivo relevance to leukemogenesis not established\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"FANCL's own stability was placed under post-translational control, with K48-linked degradation modulated by phosphorylation and the Akt/GSK-3\\u03b2/axin1 axis.\",\n      \"evidence\": \"Proteasome inhibition, K48-linkage ubiquitination assay, N-terminal deletions, axin1/GSK-3\\u03b2 co-IP, 2D-PAGE, active Akt expression\",\n      \"pmids\": [\"23783032\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Responsible E3 for FANCL K48 chains not identified\", \"Physiological trigger for FANCL turnover unclear\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"The RING\\u2013UBE2T co-crystal structure explained how FANCL selectively recruits its cognate E2 through interactions beyond the generic E3\\u2013E2 interface.\",\n      \"evidence\": \"X-ray crystallography of FANCL RING\\u2013UBE2T with interface mutagenesis and E2 selectivity assays\",\n      \"pmids\": [\"24389026\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Conformational activation of the E2~Ub for transfer not resolved\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"The ELF domain's non-covalent ubiquitin binding was assigned a regulatory role specifically enabling efficient damage-induced FANCD2 monoubiquitination in cells.\",\n      \"evidence\": \"NMR/binding assays, Ile44-patch mutagenesis, in vitro ubiquitination, and cellular complementation\",\n      \"pmids\": [\"26149689\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Source of the bound ubiquitin in vivo not identified\", \"Mechanism coupling ubiquitin binding to enhanced catalysis unclear\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Direct arsenite binding to the PHD/RING domain was shown to inhibit FANCL catalysis, providing a chemical mechanism by which an environmental toxin disrupts the FA pathway.\",\n      \"evidence\": \"In vitro arsenite-binding assay plus cellular FANCD2 monoubiquitination, chromatin recruitment, and clonogenic survival\",\n      \"pmids\": [\"28535027\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Exact cysteines coordinating arsenite not mapped\", \"In vivo relevance to arsenic toxicity not established\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"A small-molecule inhibitor of UBE2T/FANCL catalysis validated the pair as a druggable target for sensitizing cells to crosslinking chemotherapy.\",\n      \"evidence\": \"High-throughput biochemical screen with in vitro and cellular ubiquitylation assays and carboplatin clonogenic survival\",\n      \"pmids\": [\"31525021\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Binding site of the inhibitor on FANCL not defined\", \"Selectivity over other E3 ligases not characterized\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Systematic characterization of URD-domain cancer variants separated destabilizing from catalysis-impairing mutations, mapping genotype to FA-pathway dysfunction, while POI frameshift variants linked FANCL mislocalization to human reproductive disease.\",\n      \"evidence\": \"Thermal shift, FANCD2 interaction, and in vitro ubiquitination with ICL sensitivity for URD variants; immunofluorescence and ligase activity for POI patient variants\",\n      \"pmids\": [\"32420600\", \"32048394\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Causality in POI not proven beyond cellular assays\", \"In vivo consequences of individual URD variants untested\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"A CRISPR knockout combined with catalytic-mutant rescue revealed FANCL has a ubiquitin ligase-independent mitochondrial function supporting Parkin-mediated mitophagy.\",\n      \"evidence\": \"Mitochondrial fractionation, CRISPR KO, mitophagy assay, and rescue with WT and catalytically dead C307A FANCL\",\n      \"pmids\": [\"35644338\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular role of FANCL at mitochondria undefined\", \"Physiological relevance beyond Parkin-overexpressing cells unknown\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"A catalytic-cysteine knock-in mouse with genetic correction demonstrated that loss of RING E3 ligase activity alone explains all major Fanconi anemia phenotypes, formally separating catalysis from structural roles in disease.\",\n      \"evidence\": \"CRISPR knock-in mouse, FANCD2 monoubiquitination assay, phenotyping, and CRISPR/prime-editing correction with functional rescue\",\n      \"pmids\": [\"41259745\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether non-catalytic FANCL functions contribute to any residual phenotype not addressed\", \"Translatability of gene correction to human HSCs untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How FANCL's ligase-dependent DNA-repair role, its non-proteolytic Wnt/\\u03b2-catenin signaling activity, and its ligase-independent mitochondrial function are integrated within single cell types remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model linking the three activities\", \"E2 partners for non-FANCD2 substrates incompletely defined\", \"Mitochondrial molecular mechanism unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016874\", \"supporting_discovery_ids\": [0, 5, 7, 10]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 6, 7, 10]},\n      {\"term_id\": \"GO:0031386\", \"supporting_discovery_ids\": [0, 7, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [1, 19]},\n      {\"term_id\": \"GO:0000228\", \"supporting_discovery_ids\": [1, 6]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [14]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [0, 6, 15]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 7]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [10]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [14]},\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [16, 18]}\n    ],\n    \"complexes\": [\"Fanconi anemia core complex\"],\n    \"partners\": [\"UBE2T\", \"FANCD2\", \"FANCI\", \"UBE2W\", \"CTNNB1\", \"GGN\", \"AXIN1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}