{"gene":"AFAP1L2","run_date":"2026-04-28T17:12:37","timeline":{"discoveries":[{"year":2007,"finding":"AFAP1L2/XB130 is a novel adaptor protein that interacts with c-Src tyrosine kinase; co-expression in COS-7 cells results in activation of c-Src and elevated tyrosine phosphorylation of multiple proteins including XB130 itself. XB130 contains SH2- and SH3-binding motifs, two pleckstrin homology domains, and a coiled-coil region. Down-regulation with siRNA reduced c-Src activity, IL-8 production, EGF-induced phosphorylation of Akt and GSK3β in human lung epithelial cells.","method":"Co-immunoprecipitation, co-expression assays, siRNA knockdown, Western blot","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — reciprocal Co-IP, multiple orthogonal functional assays, foundational paper with strong evidence","pmids":["17412687"],"is_preprint":false},{"year":2008,"finding":"AFAP1L2/XB130 is phosphorylated by RET/PTC tyrosine kinase at tyrosine 54, which creates a critical binding site for the SH2 domains of the p85α subunit of PI3-kinase; this links RET/PTC signaling to PI3K/Akt activation in thyroid cancer cells. Downregulation of XB130 strongly reduced Akt activity without altering ERK1/2 phosphorylation.","method":"Phosphorylation site mutagenesis (Y54 mutant), Co-immunoprecipitation, siRNA knockdown, Western blot","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 1-2 — mutagenesis of specific phosphorylation site combined with Co-IP and functional knockdown with clear pathway specificity","pmids":["19060924"],"is_preprint":false},{"year":2010,"finding":"AFAP1L2/XB130 localizes to lamellipodial F-actin meshwork in response to EGF, wounding, and constitutively active Rac. Structure-function analysis showed N-terminus (167 aa) and C-terminus (63 aa) are required for translocation; PH domains and Src-targeted tyrosines are dispensable. Silencing XB130 decreased wound closure rate, inhibited Matrigel invasion, reduced lamellipodial persistence, and slowed spreading in TPC1 cells.","method":"Live imaging, immunofluorescence, structure-function mutant analysis, siRNA knockdown, wound healing assay, Matrigel invasion assay","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods including direct localization, structure-function mapping, and functional loss-of-function with defined cellular phenotypes","pmids":["21084565"],"is_preprint":false},{"year":2010,"finding":"AFAP1L2/XB130 knockdown in WRO thyroid cancer cells inhibited G1-S phase progression, induced spontaneous apoptosis, and enhanced apoptotic stimulus-induced cell death; tumor growth in nude mice was significantly reduced. Microarray identified 246 genes changed, including 57 related to cell proliferation/survival.","method":"siRNA/shRNA knockdown, flow cytometry, xenograft mouse model, microarray","journal":"The American journal of pathology","confidence":"High","confidence_rationale":"Tier 2 — clean KO/KD with defined cellular phenotypes confirmed in vivo, multiple methods","pmids":["21224076"],"is_preprint":false},{"year":2012,"finding":"AFAP1L2/XB130 (PI3KAP) is induced by cAMP in FRTL-5 thyroid cells, associates with c-Src, becomes tyrosine phosphorylated by Src family kinases, and binds p85 PI3K; this interaction is required for cAMP-dependent potentiation of IGF-I-induced DNA synthesis. Y72F mutant (unable to bind p85 PI3K) failed to enhance IGF-I-induced DNA synthesis.","method":"MALDI-TOF MS protein identification, Co-immunoprecipitation, site-directed mutagenesis (Y72F), Src family kinase inhibitors (PP1/PP2), knockdown, DNA synthesis assay","journal":"Molecular endocrinology","confidence":"High","confidence_rationale":"Tier 1-2 — specific binding site mutant validated functionally, multiple orthogonal methods","pmids":["22496359"],"is_preprint":false},{"year":2012,"finding":"AFAP1L2/XB130 regulates cancer cell proliferation and survival through PI3K/Akt downstream signals including p21Cip1/WAF1, p27Kip1, FOXO3a, and GSK3β phosphorylation independently of RET/PTC. XB130 can be phosphorylated by multiple protein tyrosine kinases.","method":"siRNA knockdown, Western blot, flow cytometry, apoptosis assays in WRO and A549 cells","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 — clean KD with defined downstream signaling readouts, single lab","pmids":["22928011"],"is_preprint":false},{"year":2013,"finding":"AFAP1L2/XB130 suppresses tumor-suppressive miRNAs (miR-33a, miR-149, miR-193a-3p) in thyroid cancer cells; these miRNAs target oncogenes MYC, FOSL1, and SLC7A5 respectively to reduce cell growth.","method":"miRNA array, qRT-PCR, ectopic overexpression, miRNA mimic transfection, dual-luciferase reporter assay for 3'UTR targeting","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 — microRNA array plus reporter assay validation, single lab with orthogonal methods","pmids":["23527086"],"is_preprint":false},{"year":2015,"finding":"AFAP1L2/XB130 interacts with scaffold protein Tks5 via the fifth SH3 domain of Tks5 binding to polyproline-rich motifs in the N-terminus of XB130; this complex also includes Src tyrosine kinase. Disruption of XB130/Tks5 binding (via W1108A mutant of Tks5 SH3 domain or XB130 N-terminal deletion) reduces cell proliferation, Src activation, and downstream PI3K/Akt phosphorylation.","method":"Yeast two-hybrid screening, Co-immunoprecipitation, structure-function mutagenesis, cell proliferation and apoptosis assays","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 — yeast two-hybrid confirmed by Co-IP, binding domain mapped by mutagenesis, functional consequences demonstrated","pmids":["26446840"],"is_preprint":false},{"year":2015,"finding":"AFAP1L2/XB130 translocates to lamellipodia and microfilamentous structures in response to NNK stimulation; overexpression enhances NNK-induced migration requiring both N- and C-termini of XB130. XB130 overexpression enhanced NNK-induced protein tyrosine phosphorylation and promoted MMP-14 translocation to cell motility-associated structures.","method":"Immunofluorescence, overexpression with truncation mutants, migration assay, Western blot","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2-3 — direct localization with functional consequence, structure-function analysis, single lab","pmids":["25980441"],"is_preprint":false},{"year":2016,"finding":"AFAP1L2/XB130 (PI3KAP) directly binds F-actin via its C-terminal region (residues 830-840) and forms multimers via its N-terminal 40 amino acids; both actin-binding and multimerization are required for actin crosslinking activity in vitro. Overexpression of XB130 enhanced endocytosis (dextran uptake), while the actin-binding deletion mutant did not.","method":"In vitro actin-crosslinking assay, Blue native-PAGE, Co-immunoprecipitation, deletion mutant analysis, endocytosis assay","journal":"Frontiers in endocrinology","confidence":"High","confidence_rationale":"Tier 1 — in vitro reconstituted actin-crosslinking assay with mutagenesis and structural analysis by native PAGE","pmids":["27462298"],"is_preprint":false},{"year":2016,"finding":"Upon EGF, PKC activator, or nicotinic acetylcholine receptor ligand stimulation, AFAP1L2/XB130 and Tks5 dissociate and translocate separately to the cell membrane; XB130 colocalizes with lamellipodial marker WAVE2 and interacts with Rac1, while Tks5 colocalizes with podosome marker N-WASP and interacts with Cdc42. Co-expression of both XB130 and Tks5 inhibits cell migration, while expression of either alone promotes it.","method":"Co-immunoprecipitation, immunofluorescence, overexpression/co-expression, migration assays, Rho GTPase activity assay","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2-3 — Co-IP for Rac1/Cdc42 interactions, direct localization with functional consequence, single lab","pmids":["27835612"],"is_preprint":false},{"year":2019,"finding":"PTPRZ dephosphorylates AFAP1L2 at tyrosine residues in vitro and in HEK293T cells; PTN-mediated inhibition of PTPRZ increases AFAP1L2 tyrosine phosphorylation, which activates the PI3K-AKT-mTOR pathway to promote oligodendrocyte precursor cell differentiation. Knockdown of AFAP1L2 suppressed OPC differentiation and PTN-induced AKT/mTOR phosphorylation.","method":"In vitro phosphatase assay, HEK293T cell phosphorylation assay, siRNA knockdown, knock-in mouse (catalytically inactive PTPRZ C→S mutation), immunofluorescence, PI3K inhibitor treatment","journal":"Glia","confidence":"High","confidence_rationale":"Tier 1-2 — in vitro phosphatase assay plus knock-in mouse model plus knockdown with clear pathway readouts, multiple orthogonal methods","pmids":["30667096"],"is_preprint":false},{"year":2021,"finding":"AFAP1L2/XB130 is expressed on the apical membrane of thyrocytes and regulates thyrocyte polarization by linking the actin filament cortex to the microtubule network; XB130-deficient thyrocytes show delayed folliculogenesis, reduced recruitment of MT-associated proteins, and disorganized acetylated tubulin under the apical membrane.","method":"XB130-GFP transfection, immunofluorescence confocal microscopy, 3D Matrigel culture, XB130 knockout mouse thyrocytes","journal":"Thyroid","confidence":"Medium","confidence_rationale":"Tier 2 — direct localization with functional consequence, knockout model with defined cellular phenotype","pmids":["34652970"],"is_preprint":false},{"year":2021,"finding":"XB130 deficiency in mice causes congenital hypothyroidism due to disorganized apical membrane structure and function of thyrocytes, with diminished thyroglobulin iodination and release. XB130 is localized mainly on the apical membrane of thyroid follicles.","method":"XB130 knockout mouse model, immunohistochemistry, immunofluorescence, Western blot, qRT-PCR, thyroxine rescue experiment","journal":"Thyroid","confidence":"High","confidence_rationale":"Tier 2 — knockout mouse model with rescue experiment, multiple orthogonal methods establishing apical membrane localization and functional consequence","pmids":["34470464"],"is_preprint":false},{"year":2023,"finding":"AFAP1L2 promotes sorafenib resistance in HCC by activating SRC, which phosphorylates FUNDC1, thereby blocking FUNDC1 recruitment of LC3B to mitochondria and inhibiting mitophagy. Artesunate reduces AFAP1L2 protein expression, suppresses SRC and FUNDC1 phosphorylation, and reactivates mitophagy.","method":"Co-immunoprecipitation, CETSA (cellular thermal shift assay), surface plasmon resonance, shRNA knockdown, Western blot, TEM, in vitro and in vivo models","journal":"Autophagy","confidence":"High","confidence_rationale":"Tier 2 — Co-IP demonstrating AFAP1L2-SRC-FUNDC1 axis, multiple orthogonal methods including CETSA and SPR for direct binding, validated in vivo","pmids":["37733919"],"is_preprint":false},{"year":2017,"finding":"The AFAP1L2/RET fusion oncogene (chromosomal rearrangement placing AFAP1L2 5' sequences upstream of RET kinase domain) has transforming ability confirmed by activation of the MAPK pathway in thyroid carcinoma.","method":"5' RACE identification, functional transformation assay, MAPK pathway activation analysis","journal":"Thyroid","confidence":"Medium","confidence_rationale":"Tier 2 — functional characterization of fusion oncogene with defined pathway activation, single study","pmids":["28351223"],"is_preprint":false},{"year":2022,"finding":"AFAP1L2/XB130 contributes to trastuzumab resistance in HER2+ gastric cancer by binding to PI3K p85α (facilitated by p-SRC Tyr416), activating PI3K/AKT; additionally, XB130 negatively regulates PTEN gene transcription, forming a positive feedback loop (SRC-XB130-PTEN).","method":"Co-immunoprecipitation, Western blot, siRNA knockdown, qRT-PCR, xenograft mouse model, CCK8 assay","journal":"Clinical & translational oncology","confidence":"Medium","confidence_rationale":"Tier 2-3 — Co-IP demonstrates XB130-PI3K p85α binding, siRNA validates functional role, single lab","pmids":["36284062"],"is_preprint":false},{"year":2024,"finding":"AFAP1L2/XB130 interacts with Src on TiO2 nanotube surfaces to activate the downstream PI3K/Akt/GSK-3β/β-catenin pathway, mediating mechanotransduction and osteogenic differentiation; filamentous actin depolymerization changes XB130 expression and distribution, affecting osteogenesis.","method":"Co-immunoprecipitation, Western blot, siRNA knockdown, overexpression, in vitro and in vivo osteogenesis assays, immunofluorescence","journal":"Acta biomaterialia","confidence":"Medium","confidence_rationale":"Tier 2-3 — Co-IP for Src interaction, actin depolymerization experiment linking cytoskeleton to XB130 function, single lab","pmids":["38360291"],"is_preprint":false},{"year":2025,"finding":"hnRNPC binds specific regions within the 3'UTR of AFAP1L2/XB130 mRNA, enhancing its stability by inhibiting recruitment of nucleases XRN1 and DIS3L2, and simultaneously interacts with eIF4E to facilitate mRNA circularization and increase translation efficiency, thereby upregulating XB130 expression and activating PI3K/Akt signaling in NSCLC.","method":"RNA pull-down assay, RNA immunoprecipitation, dual-luciferase reporter assay, Co-immunoprecipitation, qRT-PCR, Western blot","journal":"Cancer cell international","confidence":"Medium","confidence_rationale":"Tier 2 — RNA pull-down and RIP confirm direct binding, reporter assay validates functional regions, multiple orthogonal methods, single lab","pmids":["39800708"],"is_preprint":false},{"year":2015,"finding":"AFAP1L2/XB130 promotes bronchioalveolar stem cell (BASC) and Club cell proliferation during airway epithelial repair through the PI3K/Akt/GSK-3β pathway; XB130 KO mice show significantly delayed small airway repair with fewer Club cells, fewer proliferative epithelial cells, and reduced BASC expansion, with reduced phosphorylation of Akt, GSK-3β, and p85α PI3K at day 7 post-injury.","method":"XB130 knockout mouse model, naphthalene-induced injury, immunohistochemistry, Western blot, microarray, CCSP mRNA qRT-PCR","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2 — knockout mouse model with defined tissue phenotype and molecular pathway readout, single lab","pmids":["26360608"],"is_preprint":false}],"current_model":"AFAP1L2/XB130 is a cytosolic adaptor/scaffold protein that acts downstream of multiple tyrosine kinases (c-Src, RET/PTC, PTPRZ substrates): upon tyrosine phosphorylation (notably at Y54 by RET/PTC or Y72 by Src), it recruits the p85α subunit of PI3K to activate the PI3K/Akt pathway; it directly crosslinks F-actin via a C-terminal actin-binding domain and self-multimerizes via its N-terminus to localize to lamellipodia and regulate cell migration; it scaffolds a Src-XB130-Tks5 complex that controls cell proliferation and survival; in thyrocytes it links the apical actin cortex to the microtubule network to maintain follicle polarity; and in hepatocellular carcinoma it engages an AFAP1L2-SRC-FUNDC1 axis that regulates mitophagy."},"narrative":{"teleology":[{"year":2007,"claim":"Identification of AFAP1L2 as a novel adaptor protein that physically interacts with and activates c-Src established it as a signaling scaffold linking tyrosine kinase activity to downstream Akt and IL-8 signaling in epithelial cells.","evidence":"Reciprocal Co-IP, co-expression in COS-7, siRNA knockdown in lung epithelial cells","pmids":["17412687"],"confidence":"High","gaps":["Precise phosphorylation sites mediating Src interaction not mapped","Endogenous stoichiometry of Src–XB130 complex unknown","No structural data on XB130 domains"]},{"year":2008,"claim":"Demonstrating that RET/PTC phosphorylates AFAP1L2 at Y54 to create a docking site for PI3K p85α resolved how an oncogenic tyrosine kinase specifically activates the PI3K/Akt axis through this adaptor, and showed pathway selectivity (Akt but not ERK).","evidence":"Y54F mutagenesis, Co-IP, siRNA knockdown in thyroid cancer cells","pmids":["19060924"],"confidence":"High","gaps":["Whether additional phosphosites contribute to p85α binding not fully resolved","Crystal structure of pY54–SH2 interaction not determined"]},{"year":2010,"claim":"Mapping AFAP1L2 localization to lamellipodia and demonstrating its requirement for wound closure and invasion established its direct role in cell migration, while parallel work showing that knockdown inhibits G1-S progression and induces apoptosis defined its pro-survival function in vivo.","evidence":"Live imaging, structure-function mutants, siRNA/shRNA knockdown, xenograft mouse model, flow cytometry","pmids":["21084565","21224076"],"confidence":"High","gaps":["Lamellipodial recruitment mechanism (which GTPase or receptor triggers it) not resolved","Identity of the 246 downstream genes not individually validated"]},{"year":2012,"claim":"Identification of Y72 as the Src-dependent phosphosite required for p85α PI3K binding in thyrocytes, and demonstration that AFAP1L2 mediates cAMP-potentiated IGF-I signaling, extended the adaptor model to normal thyroid physiology and showed it operates downstream of multiple kinases beyond RET/PTC.","evidence":"MALDI-TOF MS, Y72F mutagenesis, Src inhibitors, DNA synthesis assay in FRTL-5 cells","pmids":["22496359","22928011"],"confidence":"High","gaps":["Whether Y54 and Y72 are functionally redundant or context-dependent unclear","Direct in vivo role in thyroid proliferation not yet tested"]},{"year":2015,"claim":"Discovery that AFAP1L2 scaffolds Tks5 via Tks5's fifth SH3 domain and that this complex co-activates Src and PI3K/Akt revealed a tripartite signaling platform, while stimulus-dependent dissociation of XB130–Tks5 with separate translocation to lamellipodia versus podosomes explained how the two adaptors divergently control migration.","evidence":"Yeast two-hybrid, Co-IP, W1108A mutagenesis, Rac1/Cdc42 activity assays, migration assays","pmids":["26446840","27835612"],"confidence":"High","gaps":["Whether Tks5–XB130 dissociation is regulated by specific kinase or phosphatase not identified","Endogenous dynamics of complex in tissues not shown"]},{"year":2015,"claim":"Knockout mouse studies demonstrated that AFAP1L2 promotes bronchioalveolar stem cell expansion and Club cell proliferation via PI3K/Akt/GSK-3β during airway repair, establishing a physiological role in tissue regeneration.","evidence":"XB130 KO mice, naphthalene-induced injury model, immunohistochemistry, Western blot","pmids":["26360608"],"confidence":"Medium","gaps":["Whether XB130 acts cell-autonomously in BASCs versus paracrine not resolved","Interaction partners in airway stem cells not identified"]},{"year":2016,"claim":"In vitro reconstitution of AFAP1L2's actin-crosslinking activity, mapping the C-terminal actin-binding domain (residues 830–840) and N-terminal multimerization domain (first 40 residues), established it as a bona fide actin crosslinker that enhances endocytosis.","evidence":"Purified protein actin-crosslinking assay, Blue native-PAGE, deletion mutants, dextran uptake assay","pmids":["27462298"],"confidence":"High","gaps":["Structural basis of actin crosslinking at atomic resolution unknown","Regulation of crosslinking activity by phosphorylation not tested"]},{"year":2019,"claim":"Demonstrating that PTPRZ dephosphorylates AFAP1L2 and that pleiotrophin-mediated PTPRZ inhibition increases AFAP1L2 phosphorylation to activate PI3K-Akt-mTOR in oligodendrocyte precursors expanded AFAP1L2's role to neural cell differentiation and identified its first upstream phosphatase.","evidence":"In vitro phosphatase assay, PTPRZ knock-in mouse (C→S), siRNA knockdown, PI3K inhibitor","pmids":["30667096"],"confidence":"High","gaps":["Specific phosphosites dephosphorylated by PTPRZ on AFAP1L2 not mapped","In vivo myelination phenotype in AFAP1L2 KO not examined"]},{"year":2021,"claim":"Knockout mouse studies proved that AFAP1L2 is essential for thyroid follicle polarization and function: it bridges the apical actin cortex to the microtubule network, and its absence causes congenital hypothyroidism with defective thyroglobulin iodination.","evidence":"XB130 KO mice, 3D Matrigel culture, confocal microscopy, thyroxine rescue","pmids":["34470464","34652970"],"confidence":"High","gaps":["Molecular link between AFAP1L2 and specific microtubule-associated proteins not identified","Whether hypothyroidism phenotype is fully penetrant across genetic backgrounds unknown"]},{"year":2023,"claim":"Identification of an AFAP1L2–SRC–FUNDC1 axis in hepatocellular carcinoma showed that AFAP1L2 activates SRC to phosphorylate FUNDC1, blocking mitophagy and conferring sorafenib resistance, revealing a novel function in mitochondrial quality control.","evidence":"Co-IP, CETSA, surface plasmon resonance, shRNA knockdown, TEM, in vivo xenograft","pmids":["37733919"],"confidence":"High","gaps":["Whether AFAP1L2 regulation of mitophagy extends beyond HCC not tested","Direct binding between AFAP1L2 and FUNDC1 versus indirect scaffolding through SRC not distinguished"]},{"year":2025,"claim":"Discovery that hnRNPC stabilizes AFAP1L2 mRNA by binding its 3'UTR and blocking nuclease recruitment, while also promoting translation via eIF4E-mediated circularization, revealed a key post-transcriptional control mechanism for AFAP1L2 expression in NSCLC.","evidence":"RNA pull-down, RIP, dual-luciferase reporter, Co-IP in NSCLC cells","pmids":["39800708"],"confidence":"Medium","gaps":["Whether hnRNPC regulation of AFAP1L2 operates in non-cancer contexts unknown","In vivo validation of hnRNPC–AFAP1L2 mRNA axis not performed"]},{"year":null,"claim":"Major open questions include the structural basis of AFAP1L2's actin-crosslinking and multimerization activities, how phosphorylation regulates the switch between its scaffolding and actin-remodeling functions, and whether AFAP1L2 plays broader roles in mitophagy regulation and mechanotransduction beyond cancer contexts.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of any AFAP1L2 domain","Phosphorylation-dependent regulation of actin crosslinking not tested","Physiological role in non-thyroid, non-lung tissues largely unexplored"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[2,9,12]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1,4,7,16]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,2,9]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[2,8,9,12]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[10,12,13]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,1,4,5,11,16,17]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[3,5]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[14]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[3,5]}],"complexes":["Src-XB130-Tks5 complex","XB130-PI3K p85α complex"],"partners":["SRC","PIK3R1","TKS5","RET","PTPRZ1","FUNDC1","RAC1","HNRNPC"],"other_free_text":[]},"mechanistic_narrative":"AFAP1L2 (also known as XB130/PI3KAP) is a multifunctional cytosolic adaptor/scaffold protein that couples tyrosine kinase signaling to PI3K/Akt activation, actin cytoskeleton remodeling, and cell migration. Upon phosphorylation by c-Src or RET/PTC at key tyrosine residues (Y54, Y72), AFAP1L2 recruits the p85α subunit of PI3K to activate the PI3K/Akt pathway, thereby promoting cell proliferation, survival, and G1-S progression while suppressing apoptosis [PMID:19060924, PMID:22496359, PMID:22928011]. AFAP1L2 directly crosslinks F-actin through its C-terminal actin-binding domain (residues 830–840) and self-multimerizes via its N-terminus, localizing to lamellipodia to regulate cell migration and endocytosis; in thyrocytes it bridges the apical actin cortex to the microtubule network, and its loss in mice causes congenital hypothyroidism from disrupted apical membrane organization [PMID:27462298, PMID:34470464, PMID:21084565]. AFAP1L2 also scaffolds a Src–XB130–Tks5 complex that controls proliferative and migratory signaling, and in hepatocellular carcinoma it activates SRC to phosphorylate FUNDC1, thereby inhibiting mitophagy and conferring sorafenib resistance [PMID:26446840, PMID:37733919]."},"prefetch_data":{"uniprot":{"accession":"Q8N4X5","full_name":"Actin filament-associated protein 1-like 2","aliases":[],"length_aa":818,"mass_kda":91.3,"function":"May play a role in a signaling cascade by enhancing the kinase activity of SRC. Contributes to SRC-regulated transcription activation","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q8N4X5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/AFAP1L2","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/AFAP1L2","total_profiled":1310},"omim":[{"mim_id":"612420","title":"ACTIN FILAMENT-ASSOCIATED PROTEIN 1-LIKE PROTEIN 2; AFAP1L2","url":"https://www.omim.org/entry/612420"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Cytosol","reliability":"Supported"},{"location":"Plasma membrane","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"lymphoid tissue","ntpm":60.8},{"tissue":"parathyroid gland","ntpm":64.6},{"tissue":"thyroid gland","ntpm":77.0}],"url":"https://www.proteinatlas.org/search/AFAP1L2"},"hgnc":{"alias_symbol":["FLJ14564","Em:AC005383.4","XB130"],"prev_symbol":["KIAA1914"]},"alphafold":{"accession":"Q8N4X5","domains":[{"cath_id":"2.30.29.30","chopping":"175-271","consensus_level":"high","plddt":89.5118,"start":175,"end":271},{"cath_id":"2.30.29.30","chopping":"358-484","consensus_level":"high","plddt":91.1,"start":358,"end":484},{"cath_id":"4.10.860","chopping":"2-47","consensus_level":"high","plddt":81.2811,"start":2,"end":47},{"cath_id":"1.10.287","chopping":"660-750","consensus_level":"high","plddt":93.034,"start":660,"end":750}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8N4X5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8N4X5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8N4X5-F1-predicted_aligned_error_v6.png","plddt_mean":63.59},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=AFAP1L2","jax_strain_url":"https://www.jax.org/strain/search?query=AFAP1L2"},"sequence":{"accession":"Q8N4X5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8N4X5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8N4X5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8N4X5"}},"corpus_meta":[{"pmid":"24387290","id":"PMC_24387290","title":"XB130 promotes proliferation and invasion of gastric cancer cells.","date":"2014","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/24387290","citation_count":86,"is_preprint":false},{"pmid":"17412687","id":"PMC_17412687","title":"XB130, a novel adaptor protein for signal transduction.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17412687","citation_count":74,"is_preprint":false},{"pmid":"37733919","id":"PMC_37733919","title":"Artesunate Sensitizes human hepatocellular carcinoma to sorafenib via exacerbating AFAP1L2-SRC-FUNDC1 axis-dependent mitophagy.","date":"2023","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/37733919","citation_count":62,"is_preprint":false},{"pmid":"19060924","id":"PMC_19060924","title":"XB130, a tissue-specific adaptor protein that couples the RET/PTC oncogenic kinase to PI 3-kinase pathway.","date":"2008","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/19060924","citation_count":57,"is_preprint":false},{"pmid":"28351223","id":"PMC_28351223","title":"Identification of Three Novel Fusion Oncogenes, SQSTM1/NTRK3, AFAP1L2/RET, and PPFIBP2/RET, in Thyroid Cancers of Young Patients in Fukushima.","date":"2017","source":"Thyroid : official journal of the American Thyroid Association","url":"https://pubmed.ncbi.nlm.nih.gov/28351223","citation_count":43,"is_preprint":false},{"pmid":"21224076","id":"PMC_21224076","title":"XB130, a novel adaptor protein, promotes thyroid tumor growth.","date":"2010","source":"The American journal of pathology","url":"https://pubmed.ncbi.nlm.nih.gov/21224076","citation_count":41,"is_preprint":false},{"pmid":"21084565","id":"PMC_21084565","title":"Adaptor protein XB130 is a Rac-controlled component of lamellipodia that regulates cell motility and invasion.","date":"2010","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/21084565","citation_count":41,"is_preprint":false},{"pmid":"22928011","id":"PMC_22928011","title":"XB130 mediates cancer cell proliferation and survival through multiple signaling events downstream of Akt.","date":"2012","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/22928011","citation_count":37,"is_preprint":false},{"pmid":"30667096","id":"PMC_30667096","title":"The PTN-PTPRZ signal activates the AFAP1L2-dependent PI3K-AKT pathway for oligodendrocyte differentiation: Targeted inactivation of PTPRZ activity in mice.","date":"2019","source":"Glia","url":"https://pubmed.ncbi.nlm.nih.gov/30667096","citation_count":36,"is_preprint":false},{"pmid":"23527086","id":"PMC_23527086","title":"XB130, a new adaptor protein, regulates expression of tumor suppressive microRNAs in cancer cells.","date":"2013","source":"PloS 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cells.","date":"2020","source":"Molecular carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/32159887","citation_count":16,"is_preprint":false},{"pmid":"25980441","id":"PMC_25980441","title":"XB130 translocation to microfilamentous structures mediates NNK-induced migration of human bronchial epithelial cells.","date":"2015","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/25980441","citation_count":16,"is_preprint":false},{"pmid":"27509056","id":"PMC_27509056","title":"XB130 is overexpressed in prostate cancer and involved in cell growth and invasion.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/27509056","citation_count":15,"is_preprint":false},{"pmid":"30820526","id":"PMC_30820526","title":"XB130 deficiency enhances carcinogen-induced skin tumorigenesis.","date":"2019","source":"Carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/30820526","citation_count":13,"is_preprint":false},{"pmid":"25892537","id":"PMC_25892537","title":"Integrated pathway and epistasis analysis reveals interactive effect of genetic variants at TERF1 and AFAP1L2 loci on melanoma risk.","date":"2015","source":"International journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/25892537","citation_count":13,"is_preprint":false},{"pmid":"25272040","id":"PMC_25272040","title":"XB130 deficiency affects tracheal epithelial differentiation during airway repair.","date":"2014","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/25272040","citation_count":12,"is_preprint":false},{"pmid":"26360608","id":"PMC_26360608","title":"XB130 promotes bronchioalveolar stem cell and Club cell proliferation in airway epithelial repair and regeneration.","date":"2015","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/26360608","citation_count":10,"is_preprint":false},{"pmid":"38360291","id":"PMC_38360291","title":"TiO2 nanotube topography enhances osteogenesis through filamentous actin and XB130-protein-mediated mechanotransduction.","date":"2024","source":"Acta biomaterialia","url":"https://pubmed.ncbi.nlm.nih.gov/38360291","citation_count":9,"is_preprint":false},{"pmid":"34652970","id":"PMC_34652970","title":"XB130 Plays an Essential Role in Folliculogenesis Through Mediating Interactions Between Microfilament and Microtubule Systems in Thyrocytes.","date":"2021","source":"Thyroid : official journal of the American Thyroid Association","url":"https://pubmed.ncbi.nlm.nih.gov/34652970","citation_count":9,"is_preprint":false},{"pmid":"30246718","id":"PMC_30246718","title":"XB130 Knockdown Inhibits the Proliferation, Invasiveness, and Metastasis of Hepatocellular Carcinoma Cells and Sensitizes them to TRAIL-Induced Apoptosis.","date":"2018","source":"Chinese medical journal","url":"https://pubmed.ncbi.nlm.nih.gov/30246718","citation_count":9,"is_preprint":false},{"pmid":"26191231","id":"PMC_26191231","title":"Expression of XB130 in human ductal breast cancer.","date":"2015","source":"International journal of clinical and experimental pathology","url":"https://pubmed.ncbi.nlm.nih.gov/26191231","citation_count":9,"is_preprint":false},{"pmid":"27462298","id":"PMC_27462298","title":"Phosphatidylinositol 3-Kinase-Associated Protein (PI3KAP)/XB130 Crosslinks Actin Filaments through Its Actin Binding and Multimerization Properties In Vitro and Enhances Endocytosis in HEK293 Cells.","date":"2016","source":"Frontiers in endocrinology","url":"https://pubmed.ncbi.nlm.nih.gov/27462298","citation_count":9,"is_preprint":false},{"pmid":"34780466","id":"PMC_34780466","title":"Adaptor protein XB130 regulates the aggressiveness of cholangiocarcinoma.","date":"2021","source":"PloS 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Mice.","date":"2022","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/35326426","citation_count":5,"is_preprint":false},{"pmid":"36284062","id":"PMC_36284062","title":"Molecular mechanism of XB130 adaptor protein mediates trastuzumab resistance in gastric cancer.","date":"2022","source":"Clinical & translational oncology : official publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico","url":"https://pubmed.ncbi.nlm.nih.gov/36284062","citation_count":2,"is_preprint":false},{"pmid":"37720672","id":"PMC_37720672","title":"The 3'‑untranslated region of XB130 regulates its mRNA stability and translational efficiency in non‑small cell lung cancer cells.","date":"2023","source":"Oncology letters","url":"https://pubmed.ncbi.nlm.nih.gov/37720672","citation_count":2,"is_preprint":false},{"pmid":"37771334","id":"PMC_37771334","title":"XB130 inhibits healing of diabetic skin ulcers through the PI3K/Akt signalling pathway.","date":"2023","source":"World journal of diabetes","url":"https://pubmed.ncbi.nlm.nih.gov/37771334","citation_count":2,"is_preprint":false},{"pmid":"34915750","id":"PMC_34915750","title":"Pathogenesis of Multinodular Goiter in Elderly XB130-Deficient Mice: Alteration of Thyroperoxidase Affinity with Iodide and Hydrogen Peroxide.","date":"2022","source":"Thyroid : official journal of the American Thyroid Association","url":"https://pubmed.ncbi.nlm.nih.gov/34915750","citation_count":2,"is_preprint":false},{"pmid":"39800708","id":"PMC_39800708","title":"Heterogeneous nuclear ribonucleoprotein C promotes non-small cell lung cancer progression by enhancing XB130 mRNA stability and translation.","date":"2025","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/39800708","citation_count":2,"is_preprint":false},{"pmid":"40268079","id":"PMC_40268079","title":"HnRNPR promotes non-small cell lung cancer progression by protecting XB130 mRNA from XRN1- and DIS3L2-mediated degradation.","date":"2025","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/40268079","citation_count":0,"is_preprint":false},{"pmid":"25997546","id":"PMC_25997546","title":"WITHDRAWN: XB130 expression in human osteosarcoma: a clinical and experimental study.","date":"2015","source":"International journal of clinical pharmacology and therapeutics","url":"https://pubmed.ncbi.nlm.nih.gov/25997546","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":24618,"output_tokens":5168,"usd":0.075687},"stage2":{"model":"claude-opus-4-6","input_tokens":8712,"output_tokens":3235,"usd":0.186652},"total_usd":0.262339,"stage1_batch_id":"msgbatch_01TqNM6p6FsoMBT2jzQTwKBr","stage2_batch_id":"msgbatch_01Ya473eco8sTHbvRymQaU8o","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2007,\n      \"finding\": \"AFAP1L2/XB130 is a novel adaptor protein that interacts with c-Src tyrosine kinase; co-expression in COS-7 cells results in activation of c-Src and elevated tyrosine phosphorylation of multiple proteins including XB130 itself. XB130 contains SH2- and SH3-binding motifs, two pleckstrin homology domains, and a coiled-coil region. Down-regulation with siRNA reduced c-Src activity, IL-8 production, EGF-induced phosphorylation of Akt and GSK3β in human lung epithelial cells.\",\n      \"method\": \"Co-immunoprecipitation, co-expression assays, siRNA knockdown, Western blot\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP, multiple orthogonal functional assays, foundational paper with strong evidence\",\n      \"pmids\": [\"17412687\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"AFAP1L2/XB130 is phosphorylated by RET/PTC tyrosine kinase at tyrosine 54, which creates a critical binding site for the SH2 domains of the p85α subunit of PI3-kinase; this links RET/PTC signaling to PI3K/Akt activation in thyroid cancer cells. Downregulation of XB130 strongly reduced Akt activity without altering ERK1/2 phosphorylation.\",\n      \"method\": \"Phosphorylation site mutagenesis (Y54 mutant), Co-immunoprecipitation, siRNA knockdown, Western blot\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — mutagenesis of specific phosphorylation site combined with Co-IP and functional knockdown with clear pathway specificity\",\n      \"pmids\": [\"19060924\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"AFAP1L2/XB130 localizes to lamellipodial F-actin meshwork in response to EGF, wounding, and constitutively active Rac. Structure-function analysis showed N-terminus (167 aa) and C-terminus (63 aa) are required for translocation; PH domains and Src-targeted tyrosines are dispensable. Silencing XB130 decreased wound closure rate, inhibited Matrigel invasion, reduced lamellipodial persistence, and slowed spreading in TPC1 cells.\",\n      \"method\": \"Live imaging, immunofluorescence, structure-function mutant analysis, siRNA knockdown, wound healing assay, Matrigel invasion assay\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods including direct localization, structure-function mapping, and functional loss-of-function with defined cellular phenotypes\",\n      \"pmids\": [\"21084565\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"AFAP1L2/XB130 knockdown in WRO thyroid cancer cells inhibited G1-S phase progression, induced spontaneous apoptosis, and enhanced apoptotic stimulus-induced cell death; tumor growth in nude mice was significantly reduced. Microarray identified 246 genes changed, including 57 related to cell proliferation/survival.\",\n      \"method\": \"siRNA/shRNA knockdown, flow cytometry, xenograft mouse model, microarray\",\n      \"journal\": \"The American journal of pathology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KO/KD with defined cellular phenotypes confirmed in vivo, multiple methods\",\n      \"pmids\": [\"21224076\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"AFAP1L2/XB130 (PI3KAP) is induced by cAMP in FRTL-5 thyroid cells, associates with c-Src, becomes tyrosine phosphorylated by Src family kinases, and binds p85 PI3K; this interaction is required for cAMP-dependent potentiation of IGF-I-induced DNA synthesis. Y72F mutant (unable to bind p85 PI3K) failed to enhance IGF-I-induced DNA synthesis.\",\n      \"method\": \"MALDI-TOF MS protein identification, Co-immunoprecipitation, site-directed mutagenesis (Y72F), Src family kinase inhibitors (PP1/PP2), knockdown, DNA synthesis assay\",\n      \"journal\": \"Molecular endocrinology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — specific binding site mutant validated functionally, multiple orthogonal methods\",\n      \"pmids\": [\"22496359\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"AFAP1L2/XB130 regulates cancer cell proliferation and survival through PI3K/Akt downstream signals including p21Cip1/WAF1, p27Kip1, FOXO3a, and GSK3β phosphorylation independently of RET/PTC. XB130 can be phosphorylated by multiple protein tyrosine kinases.\",\n      \"method\": \"siRNA knockdown, Western blot, flow cytometry, apoptosis assays in WRO and A549 cells\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — clean KD with defined downstream signaling readouts, single lab\",\n      \"pmids\": [\"22928011\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"AFAP1L2/XB130 suppresses tumor-suppressive miRNAs (miR-33a, miR-149, miR-193a-3p) in thyroid cancer cells; these miRNAs target oncogenes MYC, FOSL1, and SLC7A5 respectively to reduce cell growth.\",\n      \"method\": \"miRNA array, qRT-PCR, ectopic overexpression, miRNA mimic transfection, dual-luciferase reporter assay for 3'UTR targeting\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — microRNA array plus reporter assay validation, single lab with orthogonal methods\",\n      \"pmids\": [\"23527086\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"AFAP1L2/XB130 interacts with scaffold protein Tks5 via the fifth SH3 domain of Tks5 binding to polyproline-rich motifs in the N-terminus of XB130; this complex also includes Src tyrosine kinase. Disruption of XB130/Tks5 binding (via W1108A mutant of Tks5 SH3 domain or XB130 N-terminal deletion) reduces cell proliferation, Src activation, and downstream PI3K/Akt phosphorylation.\",\n      \"method\": \"Yeast two-hybrid screening, Co-immunoprecipitation, structure-function mutagenesis, cell proliferation and apoptosis assays\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — yeast two-hybrid confirmed by Co-IP, binding domain mapped by mutagenesis, functional consequences demonstrated\",\n      \"pmids\": [\"26446840\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"AFAP1L2/XB130 translocates to lamellipodia and microfilamentous structures in response to NNK stimulation; overexpression enhances NNK-induced migration requiring both N- and C-termini of XB130. XB130 overexpression enhanced NNK-induced protein tyrosine phosphorylation and promoted MMP-14 translocation to cell motility-associated structures.\",\n      \"method\": \"Immunofluorescence, overexpression with truncation mutants, migration assay, Western blot\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — direct localization with functional consequence, structure-function analysis, single lab\",\n      \"pmids\": [\"25980441\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"AFAP1L2/XB130 (PI3KAP) directly binds F-actin via its C-terminal region (residues 830-840) and forms multimers via its N-terminal 40 amino acids; both actin-binding and multimerization are required for actin crosslinking activity in vitro. Overexpression of XB130 enhanced endocytosis (dextran uptake), while the actin-binding deletion mutant did not.\",\n      \"method\": \"In vitro actin-crosslinking assay, Blue native-PAGE, Co-immunoprecipitation, deletion mutant analysis, endocytosis assay\",\n      \"journal\": \"Frontiers in endocrinology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro reconstituted actin-crosslinking assay with mutagenesis and structural analysis by native PAGE\",\n      \"pmids\": [\"27462298\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Upon EGF, PKC activator, or nicotinic acetylcholine receptor ligand stimulation, AFAP1L2/XB130 and Tks5 dissociate and translocate separately to the cell membrane; XB130 colocalizes with lamellipodial marker WAVE2 and interacts with Rac1, while Tks5 colocalizes with podosome marker N-WASP and interacts with Cdc42. Co-expression of both XB130 and Tks5 inhibits cell migration, while expression of either alone promotes it.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence, overexpression/co-expression, migration assays, Rho GTPase activity assay\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — Co-IP for Rac1/Cdc42 interactions, direct localization with functional consequence, single lab\",\n      \"pmids\": [\"27835612\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"PTPRZ dephosphorylates AFAP1L2 at tyrosine residues in vitro and in HEK293T cells; PTN-mediated inhibition of PTPRZ increases AFAP1L2 tyrosine phosphorylation, which activates the PI3K-AKT-mTOR pathway to promote oligodendrocyte precursor cell differentiation. Knockdown of AFAP1L2 suppressed OPC differentiation and PTN-induced AKT/mTOR phosphorylation.\",\n      \"method\": \"In vitro phosphatase assay, HEK293T cell phosphorylation assay, siRNA knockdown, knock-in mouse (catalytically inactive PTPRZ C→S mutation), immunofluorescence, PI3K inhibitor treatment\",\n      \"journal\": \"Glia\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — in vitro phosphatase assay plus knock-in mouse model plus knockdown with clear pathway readouts, multiple orthogonal methods\",\n      \"pmids\": [\"30667096\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"AFAP1L2/XB130 is expressed on the apical membrane of thyrocytes and regulates thyrocyte polarization by linking the actin filament cortex to the microtubule network; XB130-deficient thyrocytes show delayed folliculogenesis, reduced recruitment of MT-associated proteins, and disorganized acetylated tubulin under the apical membrane.\",\n      \"method\": \"XB130-GFP transfection, immunofluorescence confocal microscopy, 3D Matrigel culture, XB130 knockout mouse thyrocytes\",\n      \"journal\": \"Thyroid\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct localization with functional consequence, knockout model with defined cellular phenotype\",\n      \"pmids\": [\"34652970\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"XB130 deficiency in mice causes congenital hypothyroidism due to disorganized apical membrane structure and function of thyrocytes, with diminished thyroglobulin iodination and release. XB130 is localized mainly on the apical membrane of thyroid follicles.\",\n      \"method\": \"XB130 knockout mouse model, immunohistochemistry, immunofluorescence, Western blot, qRT-PCR, thyroxine rescue experiment\",\n      \"journal\": \"Thyroid\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — knockout mouse model with rescue experiment, multiple orthogonal methods establishing apical membrane localization and functional consequence\",\n      \"pmids\": [\"34470464\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"AFAP1L2 promotes sorafenib resistance in HCC by activating SRC, which phosphorylates FUNDC1, thereby blocking FUNDC1 recruitment of LC3B to mitochondria and inhibiting mitophagy. Artesunate reduces AFAP1L2 protein expression, suppresses SRC and FUNDC1 phosphorylation, and reactivates mitophagy.\",\n      \"method\": \"Co-immunoprecipitation, CETSA (cellular thermal shift assay), surface plasmon resonance, shRNA knockdown, Western blot, TEM, in vitro and in vivo models\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — Co-IP demonstrating AFAP1L2-SRC-FUNDC1 axis, multiple orthogonal methods including CETSA and SPR for direct binding, validated in vivo\",\n      \"pmids\": [\"37733919\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"The AFAP1L2/RET fusion oncogene (chromosomal rearrangement placing AFAP1L2 5' sequences upstream of RET kinase domain) has transforming ability confirmed by activation of the MAPK pathway in thyroid carcinoma.\",\n      \"method\": \"5' RACE identification, functional transformation assay, MAPK pathway activation analysis\",\n      \"journal\": \"Thyroid\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — functional characterization of fusion oncogene with defined pathway activation, single study\",\n      \"pmids\": [\"28351223\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"AFAP1L2/XB130 contributes to trastuzumab resistance in HER2+ gastric cancer by binding to PI3K p85α (facilitated by p-SRC Tyr416), activating PI3K/AKT; additionally, XB130 negatively regulates PTEN gene transcription, forming a positive feedback loop (SRC-XB130-PTEN).\",\n      \"method\": \"Co-immunoprecipitation, Western blot, siRNA knockdown, qRT-PCR, xenograft mouse model, CCK8 assay\",\n      \"journal\": \"Clinical & translational oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — Co-IP demonstrates XB130-PI3K p85α binding, siRNA validates functional role, single lab\",\n      \"pmids\": [\"36284062\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"AFAP1L2/XB130 interacts with Src on TiO2 nanotube surfaces to activate the downstream PI3K/Akt/GSK-3β/β-catenin pathway, mediating mechanotransduction and osteogenic differentiation; filamentous actin depolymerization changes XB130 expression and distribution, affecting osteogenesis.\",\n      \"method\": \"Co-immunoprecipitation, Western blot, siRNA knockdown, overexpression, in vitro and in vivo osteogenesis assays, immunofluorescence\",\n      \"journal\": \"Acta biomaterialia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2-3 — Co-IP for Src interaction, actin depolymerization experiment linking cytoskeleton to XB130 function, single lab\",\n      \"pmids\": [\"38360291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"hnRNPC binds specific regions within the 3'UTR of AFAP1L2/XB130 mRNA, enhancing its stability by inhibiting recruitment of nucleases XRN1 and DIS3L2, and simultaneously interacts with eIF4E to facilitate mRNA circularization and increase translation efficiency, thereby upregulating XB130 expression and activating PI3K/Akt signaling in NSCLC.\",\n      \"method\": \"RNA pull-down assay, RNA immunoprecipitation, dual-luciferase reporter assay, Co-immunoprecipitation, qRT-PCR, Western blot\",\n      \"journal\": \"Cancer cell international\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — RNA pull-down and RIP confirm direct binding, reporter assay validates functional regions, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"39800708\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"AFAP1L2/XB130 promotes bronchioalveolar stem cell (BASC) and Club cell proliferation during airway epithelial repair through the PI3K/Akt/GSK-3β pathway; XB130 KO mice show significantly delayed small airway repair with fewer Club cells, fewer proliferative epithelial cells, and reduced BASC expansion, with reduced phosphorylation of Akt, GSK-3β, and p85α PI3K at day 7 post-injury.\",\n      \"method\": \"XB130 knockout mouse model, naphthalene-induced injury, immunohistochemistry, Western blot, microarray, CCSP mRNA qRT-PCR\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — knockout mouse model with defined tissue phenotype and molecular pathway readout, single lab\",\n      \"pmids\": [\"26360608\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"AFAP1L2/XB130 is a cytosolic adaptor/scaffold protein that acts downstream of multiple tyrosine kinases (c-Src, RET/PTC, PTPRZ substrates): upon tyrosine phosphorylation (notably at Y54 by RET/PTC or Y72 by Src), it recruits the p85α subunit of PI3K to activate the PI3K/Akt pathway; it directly crosslinks F-actin via a C-terminal actin-binding domain and self-multimerizes via its N-terminus to localize to lamellipodia and regulate cell migration; it scaffolds a Src-XB130-Tks5 complex that controls cell proliferation and survival; in thyrocytes it links the apical actin cortex to the microtubule network to maintain follicle polarity; and in hepatocellular carcinoma it engages an AFAP1L2-SRC-FUNDC1 axis that regulates mitophagy.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"AFAP1L2 (also known as XB130/PI3KAP) is a multifunctional cytosolic adaptor/scaffold protein that couples tyrosine kinase signaling to PI3K/Akt activation, actin cytoskeleton remodeling, and cell migration. Upon phosphorylation by c-Src or RET/PTC at key tyrosine residues (Y54, Y72), AFAP1L2 recruits the p85α subunit of PI3K to activate the PI3K/Akt pathway, thereby promoting cell proliferation, survival, and G1-S progression while suppressing apoptosis [PMID:19060924, PMID:22496359, PMID:22928011]. AFAP1L2 directly crosslinks F-actin through its C-terminal actin-binding domain (residues 830–840) and self-multimerizes via its N-terminus, localizing to lamellipodia to regulate cell migration and endocytosis; in thyrocytes it bridges the apical actin cortex to the microtubule network, and its loss in mice causes congenital hypothyroidism from disrupted apical membrane organization [PMID:27462298, PMID:34470464, PMID:21084565]. AFAP1L2 also scaffolds a Src–XB130–Tks5 complex that controls proliferative and migratory signaling, and in hepatocellular carcinoma it activates SRC to phosphorylate FUNDC1, thereby inhibiting mitophagy and conferring sorafenib resistance [PMID:26446840, PMID:37733919].\",\n  \"teleology\": [\n    {\n      \"year\": 2007,\n      \"claim\": \"Identification of AFAP1L2 as a novel adaptor protein that physically interacts with and activates c-Src established it as a signaling scaffold linking tyrosine kinase activity to downstream Akt and IL-8 signaling in epithelial cells.\",\n      \"evidence\": \"Reciprocal Co-IP, co-expression in COS-7, siRNA knockdown in lung epithelial cells\",\n      \"pmids\": [\"17412687\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Precise phosphorylation sites mediating Src interaction not mapped\", \"Endogenous stoichiometry of Src–XB130 complex unknown\", \"No structural data on XB130 domains\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Demonstrating that RET/PTC phosphorylates AFAP1L2 at Y54 to create a docking site for PI3K p85α resolved how an oncogenic tyrosine kinase specifically activates the PI3K/Akt axis through this adaptor, and showed pathway selectivity (Akt but not ERK).\",\n      \"evidence\": \"Y54F mutagenesis, Co-IP, siRNA knockdown in thyroid cancer cells\",\n      \"pmids\": [\"19060924\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether additional phosphosites contribute to p85α binding not fully resolved\", \"Crystal structure of pY54–SH2 interaction not determined\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Mapping AFAP1L2 localization to lamellipodia and demonstrating its requirement for wound closure and invasion established its direct role in cell migration, while parallel work showing that knockdown inhibits G1-S progression and induces apoptosis defined its pro-survival function in vivo.\",\n      \"evidence\": \"Live imaging, structure-function mutants, siRNA/shRNA knockdown, xenograft mouse model, flow cytometry\",\n      \"pmids\": [\"21084565\", \"21224076\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Lamellipodial recruitment mechanism (which GTPase or receptor triggers it) not resolved\", \"Identity of the 246 downstream genes not individually validated\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Identification of Y72 as the Src-dependent phosphosite required for p85α PI3K binding in thyrocytes, and demonstration that AFAP1L2 mediates cAMP-potentiated IGF-I signaling, extended the adaptor model to normal thyroid physiology and showed it operates downstream of multiple kinases beyond RET/PTC.\",\n      \"evidence\": \"MALDI-TOF MS, Y72F mutagenesis, Src inhibitors, DNA synthesis assay in FRTL-5 cells\",\n      \"pmids\": [\"22496359\", \"22928011\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether Y54 and Y72 are functionally redundant or context-dependent unclear\", \"Direct in vivo role in thyroid proliferation not yet tested\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Discovery that AFAP1L2 scaffolds Tks5 via Tks5's fifth SH3 domain and that this complex co-activates Src and PI3K/Akt revealed a tripartite signaling platform, while stimulus-dependent dissociation of XB130–Tks5 with separate translocation to lamellipodia versus podosomes explained how the two adaptors divergently control migration.\",\n      \"evidence\": \"Yeast two-hybrid, Co-IP, W1108A mutagenesis, Rac1/Cdc42 activity assays, migration assays\",\n      \"pmids\": [\"26446840\", \"27835612\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether Tks5–XB130 dissociation is regulated by specific kinase or phosphatase not identified\", \"Endogenous dynamics of complex in tissues not shown\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Knockout mouse studies demonstrated that AFAP1L2 promotes bronchioalveolar stem cell expansion and Club cell proliferation via PI3K/Akt/GSK-3β during airway repair, establishing a physiological role in tissue regeneration.\",\n      \"evidence\": \"XB130 KO mice, naphthalene-induced injury model, immunohistochemistry, Western blot\",\n      \"pmids\": [\"26360608\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether XB130 acts cell-autonomously in BASCs versus paracrine not resolved\", \"Interaction partners in airway stem cells not identified\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"In vitro reconstitution of AFAP1L2's actin-crosslinking activity, mapping the C-terminal actin-binding domain (residues 830–840) and N-terminal multimerization domain (first 40 residues), established it as a bona fide actin crosslinker that enhances endocytosis.\",\n      \"evidence\": \"Purified protein actin-crosslinking assay, Blue native-PAGE, deletion mutants, dextran uptake assay\",\n      \"pmids\": [\"27462298\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of actin crosslinking at atomic resolution unknown\", \"Regulation of crosslinking activity by phosphorylation not tested\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Demonstrating that PTPRZ dephosphorylates AFAP1L2 and that pleiotrophin-mediated PTPRZ inhibition increases AFAP1L2 phosphorylation to activate PI3K-Akt-mTOR in oligodendrocyte precursors expanded AFAP1L2's role to neural cell differentiation and identified its first upstream phosphatase.\",\n      \"evidence\": \"In vitro phosphatase assay, PTPRZ knock-in mouse (C→S), siRNA knockdown, PI3K inhibitor\",\n      \"pmids\": [\"30667096\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific phosphosites dephosphorylated by PTPRZ on AFAP1L2 not mapped\", \"In vivo myelination phenotype in AFAP1L2 KO not examined\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Knockout mouse studies proved that AFAP1L2 is essential for thyroid follicle polarization and function: it bridges the apical actin cortex to the microtubule network, and its absence causes congenital hypothyroidism with defective thyroglobulin iodination.\",\n      \"evidence\": \"XB130 KO mice, 3D Matrigel culture, confocal microscopy, thyroxine rescue\",\n      \"pmids\": [\"34470464\", \"34652970\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular link between AFAP1L2 and specific microtubule-associated proteins not identified\", \"Whether hypothyroidism phenotype is fully penetrant across genetic backgrounds unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identification of an AFAP1L2–SRC–FUNDC1 axis in hepatocellular carcinoma showed that AFAP1L2 activates SRC to phosphorylate FUNDC1, blocking mitophagy and conferring sorafenib resistance, revealing a novel function in mitochondrial quality control.\",\n      \"evidence\": \"Co-IP, CETSA, surface plasmon resonance, shRNA knockdown, TEM, in vivo xenograft\",\n      \"pmids\": [\"37733919\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether AFAP1L2 regulation of mitophagy extends beyond HCC not tested\", \"Direct binding between AFAP1L2 and FUNDC1 versus indirect scaffolding through SRC not distinguished\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Discovery that hnRNPC stabilizes AFAP1L2 mRNA by binding its 3'UTR and blocking nuclease recruitment, while also promoting translation via eIF4E-mediated circularization, revealed a key post-transcriptional control mechanism for AFAP1L2 expression in NSCLC.\",\n      \"evidence\": \"RNA pull-down, RIP, dual-luciferase reporter, Co-IP in NSCLC cells\",\n      \"pmids\": [\"39800708\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether hnRNPC regulation of AFAP1L2 operates in non-cancer contexts unknown\", \"In vivo validation of hnRNPC–AFAP1L2 mRNA axis not performed\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Major open questions include the structural basis of AFAP1L2's actin-crosslinking and multimerization activities, how phosphorylation regulates the switch between its scaffolding and actin-remodeling functions, and whether AFAP1L2 plays broader roles in mitophagy regulation and mechanotransduction beyond cancer contexts.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No high-resolution structure of any AFAP1L2 domain\", \"Phosphorylation-dependent regulation of actin crosslinking not tested\", \"Physiological role in non-thyroid, non-lung tissues largely unexplored\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [2, 9, 12]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1, 4, 7, 16]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 2, 9]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [2, 8, 9, 12]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [10, 12, 13]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 1, 4, 5, 11, 16, 17]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [3, 5]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [14]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [3, 5]}\n    ],\n    \"complexes\": [\n      \"Src-XB130-Tks5 complex\",\n      \"XB130-PI3K p85α complex\"\n    ],\n    \"partners\": [\n      \"SRC\",\n      \"PIK3R1\",\n      \"TKS5\",\n      \"RET\",\n      \"PTPRZ1\",\n      \"FUNDC1\",\n      \"RAC1\",\n      \"HNRNPC\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}