{"gene":"GAS2L3","run_date":"2026-06-10T01:55:21","timeline":{"discoveries":[{"year":2012,"finding":"GAS2L3 is a transcriptional target of the DREAM complex and localizes to the spindle midzone and midbody during anaphase and cytokinesis; RNAi-mediated knockdown causes chromosome segregation defects, multinucleation, multi-lobed nuclei, chromosome loss, and aneuploidy; biochemical studies show GAS2L3 binds and bundles microtubules and F-actin in vitro.","method":"RNAi knockdown, time-lapse videomicroscopy, in vitro microtubule/actin bundling assay, immunofluorescence localization","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (biochemical in vitro assay, RNAi with cellular phenotype, live imaging, localization), single lab but comprehensive","pmids":["22344256"],"is_preprint":false},{"year":2013,"finding":"Gas2l3 protein is targeted for ubiquitin-mediated proteolysis by the APC/C(Cdh1) complex but not by APC/C(Cdc20), and is phosphorylated by Cdk1 in mitosis. Late in cytokinesis, Gas2l3 localizes exclusively to constriction sites of the intercellular bridge; overexpression of Gas2l3 specifically blocks cell abscission.","method":"Cell-free ubiquitination assays (frog egg and human cell extracts), Cdk1 phosphorylation assay, live-cell imaging, overexpression abscission assay","journal":"PloS one","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — in vitro reconstitution of APC/C-mediated proteolysis in two cell-free systems, Cdk1 kinase assay, functional overexpression phenotype, multiple orthogonal methods","pmids":["23469016"],"is_preprint":false},{"year":2014,"finding":"GAS2L3 interacts with the chromosomal passenger complex (CPC): its conserved GAR domain directly binds the C-terminus of borealin and the N-terminus of survivin. The GAR domain is required for localization of GAS2L3 to the constriction zone during abscission, placing GAS2L3 as a downstream CPC effector in cytokinetic abscission.","method":"Biochemical interaction assays (pulldown/co-IP with CPC subunits), domain deletion/mutagenesis, immunofluorescence localization","journal":"The FEBS journal","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — direct biochemical interaction mapped to specific domains with mutagenesis and functional localization readout, single lab","pmids":["24571573"],"is_preprint":false},{"year":2014,"finding":"GAS2L3 (G2L3) localizes to both actin and microtubules via fluorescence microscopy but, unlike G2L1 and G2L2, exogenous expression of G2L3 does not influence microtubule stability, dynamics, or guidance along actin stress fibres. The functions of G2L1 and G2L2 in actin-MT crosstalk depend on SxIP/SxLP motifs at their C-termini that associate with end-binding (EB) proteins.","method":"Fluorescence microscopy, live-cell imaging, biochemical analysis of EB protein binding","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — multiple methods but the GAS2L3-specific finding is largely negative (no MT stabilization effect); localization confirmed but functional distinction from paralogs relies on single-lab data","pmids":["24706950"],"is_preprint":false},{"year":2014,"finding":"Gas2l3 is required for normal brain morphogenesis in zebrafish; knockdown of gas2l3 causes abnormal brain ventricle formation and impairs cell proliferation in brain tissue, and the phenotype is rescued by exogenous gas2l3 RNA, establishing the cell cycle/cytokinesis role of Gas2l3 as essential for brain tissue homeostasis in vivo.","method":"Morpholino knockdown in zebrafish, spatiotemporal expression analysis, mRNA rescue experiment, histological analysis","journal":"Developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo loss-of-function with mRNA rescue in zebrafish, single lab, phenotype well-characterized but mechanistic depth limited","pmids":["25131197"],"is_preprint":false},{"year":2017,"finding":"Deletion of Gas2l3 in mice causes neonatal death from heart failure. GAS2L3 deficiency in cardiomyocytes leads to inhibition of cardiomyocyte proliferation, premature binucleation from incomplete cytokinesis, unresolved midbody structures, cardiomyocyte hypertrophy during embryonic development, and upregulation of a p53-transcriptional program including p21. Cardiomyocyte-specific deletion confirmed the cardiac cell-autonomous requirement.","method":"Constitutive and cardiomyocyte-specific knockout mice, histology, immunofluorescence, western blotting, gene expression analysis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional knockout with organ-specific rescue, multiple orthogonal phenotypic readouts, in vivo mechanistic validation","pmids":["28698371"],"is_preprint":false},{"year":2012,"finding":"Necdin controls the hematopoietic stem cell response to genotoxic stress via a GAS2L3-dependent mechanism (cell-cycle-independent pathway), placing GAS2L3 downstream of necdin in a p53-stress response pathway.","method":"Genetic epistasis using necdin-null HSC transplantation, irradiation and chemotherapy challenge","journal":"Blood","confidence":"Low","confidence_rationale":"Tier 3 / Weak — GAS2L3 involvement inferred by genetic epistasis in a single study; GAS2L3-specific molecular mechanism not directly dissected","pmids":["22776820"],"is_preprint":false},{"year":2025,"finding":"GAS2L3 undergoes liquid-liquid phase separation (LLPS) via its intrinsically disordered region (IDR) at the midbody, forming dynamic condensates validated by FRAP and in vitro droplet assays. GAS2L3 scaffolds CHMP4B condensate formation at the midbody through phase separation, accelerating cytokinetic abscission. GAS2L3 knockdown or IDR deletion causes defective cytokinesis, G1 arrest, and reduced tumorigenicity in HCC cells.","method":"FRAP, time-lapse imaging, in vitro droplet formation assay, IDR-deletion construct, GAS2L3 knockdown with cytokinesis and cell-cycle readouts, co-localization with CHMP4B","journal":"Journal of advanced research","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — multiple orthogonal methods (FRAP, in vitro LLPS, mutagenesis of IDR, functional KD phenotype), single lab","pmids":["41177429"],"is_preprint":false},{"year":2025,"finding":"CCA-derived exosomes contain GAS2L3 protein, and GAS2L3 promotes fibroblast migration and invasion; knockdown of GAS2L3 reduces fibroblast recruitment, establishing an extracellular/exosomal role for GAS2L3 in cancer-associated fibroblast chemotaxis.","method":"Conditioned media and exosome treatment of fibroblasts, tandem mass spectrometry of exosomal proteins, GAS2L3 loss-of-function in fibroblast migration assays","journal":"European journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — proteomic identification plus functional knockdown migration assay, single lab, limited mechanistic depth","pmids":["40664041"],"is_preprint":false}],"current_model":"GAS2L3 is a DREAM complex target gene that encodes a cytoskeletal crosslinker with CH (actin-binding) and GAR (microtubule-binding) domains; it localizes to the spindle midzone and midbody where it bundles F-actin and microtubules, interacts with the chromosomal passenger complex (CPC) via its GAR domain binding borealin and survivin, undergoes APC/C(Cdh1)-mediated ubiquitin proteolysis and Cdk1 phosphorylation to control its mitotic abundance, and at the midbody constriction zone forms IDR-driven liquid-liquid phase separation condensates that scaffold CHMP4B recruitment to drive cytokinetic abscission; loss of GAS2L3 causes chromosome segregation errors, cytokinesis failure, and—in vivo—cardiomyocyte binucleation leading to neonatal heart failure."},"narrative":{"mechanistic_narrative":"GAS2L3 is a cell-cycle-regulated cytoskeletal crosslinker that acts at the spindle midzone and midbody to ensure faithful chromosome segregation and cytokinetic abscission [PMID:22344256]. It directly binds and bundles both microtubules and F-actin in vitro and is transcriptionally controlled as a DREAM complex target, with loss of function producing chromosome segregation defects, multinucleation, and aneuploidy [PMID:22344256]. Its mitotic abundance is tightly timed: GAS2L3 is phosphorylated by Cdk1 in mitosis and targeted for degradation by APC/C(Cdh1) but not APC/C(Cdc20), and late in cytokinesis it concentrates at constriction sites of the intercellular bridge, where overexpression blocks abscission [PMID:23469016]. GAS2L3 functions as a downstream effector of the chromosomal passenger complex, its conserved GAR domain binding the borealin C-terminus and survivin N-terminus, an interaction required for recruitment to the constriction zone [PMID:24571573]. At the midbody it drives abscission by forming intrinsically disordered region (IDR)-dependent liquid-liquid phase separation condensates that scaffold CHMP4B condensate assembly; IDR deletion or knockdown causes defective cytokinesis and G1 arrest [PMID:41177429]. In vivo, GAS2L3 deficiency causes premature cardiomyocyte binucleation from incomplete cytokinesis, unresolved midbodies, and a p53/p21 program, leading to neonatal heart failure in knockout mice [PMID:28698371], and is required for normal brain morphogenesis and cell proliferation in zebrafish [PMID:25131197].","teleology":[{"year":2012,"claim":"Established GAS2L3 as a DREAM-controlled midzone/midbody protein whose loss disrupts genome stability, defining its core role in mitosis and cytokinesis.","evidence":"RNAi knockdown with live imaging, in vitro microtubule/actin bundling assays, and immunofluorescence localization","pmids":["22344256"],"confidence":"High","gaps":["Does not resolve how GAS2L3 is recruited to the midbody","Molecular partners at the midzone not identified"]},{"year":2012,"claim":"Placed GAS2L3 downstream of necdin in a hematopoietic stem cell genotoxic stress response, hinting at a role beyond cell-cycle mechanics.","evidence":"Genetic epistasis using necdin-null HSC transplantation with irradiation/chemotherapy challenge","pmids":["22776820"],"confidence":"Low","gaps":["GAS2L3-specific molecular mechanism not directly dissected","Inferred by epistasis in a single study","Link to its mitotic function unclear"]},{"year":2013,"claim":"Defined how GAS2L3 abundance is timed across the cell cycle, showing it is a Cdk1 substrate and an APC/C(Cdh1)-specific degradation target, and that its levels must be controlled for abscission to proceed.","evidence":"Cell-free ubiquitination assays in frog egg and human extracts, Cdk1 phosphorylation assay, and overexpression abscission assay","pmids":["23469016"],"confidence":"High","gaps":["Cdk1 phosphosites and their functional consequence not mapped","How degradation timing couples to abscission completion unresolved"]},{"year":2014,"claim":"Identified the GAR domain as the CPC-binding module linking GAS2L3 to borealin and survivin, establishing it as a CPC effector recruited to the constriction zone.","evidence":"Pulldown/co-IP with CPC subunits, domain deletion/mutagenesis, and immunofluorescence localization","pmids":["24571573"],"confidence":"High","gaps":["Reciprocal validation and structural detail of the GAR-borealin/survivin interface not provided","How CPC binding triggers downstream abscission events unknown"]},{"year":2014,"claim":"Distinguished GAS2L3 from its paralogs G2L1/G2L2, showing it localizes to actin and microtubules but lacks EB-dependent microtubule-stabilizing activity, refining its functional niche.","evidence":"Fluorescence microscopy, live-cell imaging, and biochemical analysis of EB protein binding","pmids":["24706950"],"confidence":"Medium","gaps":["GAS2L3-specific finding is largely negative","Single-lab data on functional distinction from paralogs"]},{"year":2014,"claim":"Demonstrated an in vivo developmental requirement for Gas2l3 in zebrafish brain morphogenesis and proliferation, confirmed by mRNA rescue.","evidence":"Morpholino knockdown with mRNA rescue and histological analysis in zebrafish","pmids":["25131197"],"confidence":"Medium","gaps":["Mechanistic depth limited","Whether the phenotype is purely cytokinesis-driven not established"]},{"year":2017,"claim":"Provided definitive in vivo evidence that GAS2L3 cytokinesis function is essential in the heart, linking its loss to cardiomyocyte binucleation, a p53/p21 program, and neonatal lethality.","evidence":"Constitutive and cardiomyocyte-specific knockout mice with histology, immunofluorescence, and gene expression analysis","pmids":["28698371"],"confidence":"High","gaps":["Mechanism connecting failed abscission to p53 activation not detailed","Tissue-selective vulnerability of cardiomyocytes unexplained"]},{"year":2025,"claim":"Revealed the biophysical mechanism of GAS2L3 at the midbody — IDR-driven phase separation that scaffolds CHMP4B condensates to accelerate abscission — and tied it to tumorigenicity.","evidence":"FRAP, in vitro droplet assays, IDR-deletion constructs, and knockdown with cytokinesis/cell-cycle readouts in HCC cells","pmids":["41177429"],"confidence":"High","gaps":["Single lab","How IDR condensates physically promote CHMP4B/ESCRT polymerization not resolved","Relationship between LLPS and the GAR-CPC recruitment pathway unclear"]},{"year":2025,"claim":"Extended GAS2L3 beyond intracellular mitosis to an exosomal role promoting cancer-associated fibroblast migration and recruitment.","evidence":"Exosome proteomics and GAS2L3 loss-of-function fibroblast migration assays","pmids":["40664041"],"confidence":"Medium","gaps":["Limited mechanistic depth","How a cytoskeletal/midbody protein acts extracellularly is unexplained"]},{"year":null,"claim":"How the cell-cycle regulation (Cdk1/APC-Cdh1), CPC recruitment, and IDR-based phase separation are integrated into a single abscission program, and how this connects to the p53 stress responses seen in vivo, remains unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No unified model linking degradation timing, CPC binding, and condensate formation","Mechanism coupling failed cytokinesis to p53/p21 activation undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,3]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[2,7]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0,3]},{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[0,1]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0,1,5]}],"complexes":[],"partners":["BIRC5","CDCA8","CHMP4B"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q86XJ1","full_name":"GAS2-like protein 3","aliases":["Growth arrest-specific protein 2-like 3"],"length_aa":694,"mass_kda":75.2,"function":"Cytoskeletal linker protein. May promote and stabilize the formation of the actin and microtubule network","subcellular_location":"Cytoplasm; Cytoplasm, cytoskeleton","url":"https://www.uniprot.org/uniprotkb/Q86XJ1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/GAS2L3","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/GAS2L3","total_profiled":1310},"omim":[{"mim_id":"617224","title":"GROWTH ARREST-SPECIFIC 2-LIKE 3; GAS2L3","url":"https://www.omim.org/entry/617224"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/GAS2L3"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q86XJ1","domains":[{"cath_id":"1.10.418.10","chopping":"30-175","consensus_level":"medium","plddt":92.9936,"start":30,"end":175},{"cath_id":"3.30.920.20","chopping":"176-193_207-296","consensus_level":"medium","plddt":86.9335,"start":176,"end":296}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86XJ1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q86XJ1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q86XJ1-F1-predicted_aligned_error_v6.png","plddt_mean":59.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GAS2L3","jax_strain_url":"https://www.jax.org/strain/search?query=GAS2L3"},"sequence":{"accession":"Q86XJ1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q86XJ1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q86XJ1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86XJ1"}},"corpus_meta":[{"pmid":"22776820","id":"PMC_22776820","title":"Necdin, a p53 target gene, regulates the quiescence and response to genotoxic stress of hematopoietic stem/progenitor cells.","date":"2012","source":"Blood","url":"https://pubmed.ncbi.nlm.nih.gov/22776820","citation_count":57,"is_preprint":false},{"pmid":"24706950","id":"PMC_24706950","title":"GAS2-like proteins mediate communication between microtubules and actin through interactions with end-binding proteins.","date":"2014","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/24706950","citation_count":56,"is_preprint":false},{"pmid":"22344256","id":"PMC_22344256","title":"GAS2L3, a target gene of the DREAM complex, is required for proper cytokinesis and genomic stability.","date":"2012","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/22344256","citation_count":40,"is_preprint":false},{"pmid":"35685361","id":"PMC_35685361","title":"Integrative RNA profiling of TBEV-infected neurons and astrocytes reveals potential pathogenic 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Pathogenesis via the VEGF Signaling Pathway.","date":"2021","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/34912698","citation_count":13,"is_preprint":false},{"pmid":"38767906","id":"PMC_38767906","title":"Predicting Risks of Dry Eye Disease Development Using a Genome-Wide Polygenic Risk Score Model.","date":"2024","source":"Translational vision science & technology","url":"https://pubmed.ncbi.nlm.nih.gov/38767906","citation_count":10,"is_preprint":false},{"pmid":"24571573","id":"PMC_24571573","title":"The GAR domain of GAS2L3 mediates binding to the chromosomal passenger complex and is required for localization of GAS2L3 to the constriction zone during abscission.","date":"2014","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/24571573","citation_count":7,"is_preprint":false},{"pmid":"39391485","id":"PMC_39391485","title":"Landscape of epithelial cell subpopulations in the human esophageal squamous cell carcinoma 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\"method\": \"RNAi knockdown, time-lapse videomicroscopy, in vitro microtubule/actin bundling assay, immunofluorescence localization\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (biochemical in vitro assay, RNAi with cellular phenotype, live imaging, localization), single lab but comprehensive\",\n      \"pmids\": [\"22344256\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Gas2l3 protein is targeted for ubiquitin-mediated proteolysis by the APC/C(Cdh1) complex but not by APC/C(Cdc20), and is phosphorylated by Cdk1 in mitosis. Late in cytokinesis, Gas2l3 localizes exclusively to constriction sites of the intercellular bridge; overexpression of Gas2l3 specifically blocks cell abscission.\",\n      \"method\": \"Cell-free ubiquitination assays (frog egg and human cell extracts), Cdk1 phosphorylation assay, live-cell imaging, overexpression abscission assay\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — in vitro reconstitution of APC/C-mediated proteolysis in two cell-free systems, Cdk1 kinase assay, functional overexpression phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"23469016\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"GAS2L3 interacts with the chromosomal passenger complex (CPC): its conserved GAR domain directly binds the C-terminus of borealin and the N-terminus of survivin. The GAR domain is required for localization of GAS2L3 to the constriction zone during abscission, placing GAS2L3 as a downstream CPC effector in cytokinetic abscission.\",\n      \"method\": \"Biochemical interaction assays (pulldown/co-IP with CPC subunits), domain deletion/mutagenesis, immunofluorescence localization\",\n      \"journal\": \"The FEBS journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — direct biochemical interaction mapped to specific domains with mutagenesis and functional localization readout, single lab\",\n      \"pmids\": [\"24571573\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"GAS2L3 (G2L3) localizes to both actin and microtubules via fluorescence microscopy but, unlike G2L1 and G2L2, exogenous expression of G2L3 does not influence microtubule stability, dynamics, or guidance along actin stress fibres. The functions of G2L1 and G2L2 in actin-MT crosstalk depend on SxIP/SxLP motifs at their C-termini that associate with end-binding (EB) proteins.\",\n      \"method\": \"Fluorescence microscopy, live-cell imaging, biochemical analysis of EB protein binding\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — multiple methods but the GAS2L3-specific finding is largely negative (no MT stabilization effect); localization confirmed but functional distinction from paralogs relies on single-lab data\",\n      \"pmids\": [\"24706950\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Gas2l3 is required for normal brain morphogenesis in zebrafish; knockdown of gas2l3 causes abnormal brain ventricle formation and impairs cell proliferation in brain tissue, and the phenotype is rescued by exogenous gas2l3 RNA, establishing the cell cycle/cytokinesis role of Gas2l3 as essential for brain tissue homeostasis in vivo.\",\n      \"method\": \"Morpholino knockdown in zebrafish, spatiotemporal expression analysis, mRNA rescue experiment, histological analysis\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo loss-of-function with mRNA rescue in zebrafish, single lab, phenotype well-characterized but mechanistic depth limited\",\n      \"pmids\": [\"25131197\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Deletion of Gas2l3 in mice causes neonatal death from heart failure. GAS2L3 deficiency in cardiomyocytes leads to inhibition of cardiomyocyte proliferation, premature binucleation from incomplete cytokinesis, unresolved midbody structures, cardiomyocyte hypertrophy during embryonic development, and upregulation of a p53-transcriptional program including p21. Cardiomyocyte-specific deletion confirmed the cardiac cell-autonomous requirement.\",\n      \"method\": \"Constitutive and cardiomyocyte-specific knockout mice, histology, immunofluorescence, western blotting, gene expression analysis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional knockout with organ-specific rescue, multiple orthogonal phenotypic readouts, in vivo mechanistic validation\",\n      \"pmids\": [\"28698371\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Necdin controls the hematopoietic stem cell response to genotoxic stress via a GAS2L3-dependent mechanism (cell-cycle-independent pathway), placing GAS2L3 downstream of necdin in a p53-stress response pathway.\",\n      \"method\": \"Genetic epistasis using necdin-null HSC transplantation, irradiation and chemotherapy challenge\",\n      \"journal\": \"Blood\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — GAS2L3 involvement inferred by genetic epistasis in a single study; GAS2L3-specific molecular mechanism not directly dissected\",\n      \"pmids\": [\"22776820\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"GAS2L3 undergoes liquid-liquid phase separation (LLPS) via its intrinsically disordered region (IDR) at the midbody, forming dynamic condensates validated by FRAP and in vitro droplet assays. GAS2L3 scaffolds CHMP4B condensate formation at the midbody through phase separation, accelerating cytokinetic abscission. GAS2L3 knockdown or IDR deletion causes defective cytokinesis, G1 arrest, and reduced tumorigenicity in HCC cells.\",\n      \"method\": \"FRAP, time-lapse imaging, in vitro droplet formation assay, IDR-deletion construct, GAS2L3 knockdown with cytokinesis and cell-cycle readouts, co-localization with CHMP4B\",\n      \"journal\": \"Journal of advanced research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — multiple orthogonal methods (FRAP, in vitro LLPS, mutagenesis of IDR, functional KD phenotype), single lab\",\n      \"pmids\": [\"41177429\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CCA-derived exosomes contain GAS2L3 protein, and GAS2L3 promotes fibroblast migration and invasion; knockdown of GAS2L3 reduces fibroblast recruitment, establishing an extracellular/exosomal role for GAS2L3 in cancer-associated fibroblast chemotaxis.\",\n      \"method\": \"Conditioned media and exosome treatment of fibroblasts, tandem mass spectrometry of exosomal proteins, GAS2L3 loss-of-function in fibroblast migration assays\",\n      \"journal\": \"European journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — proteomic identification plus functional knockdown migration assay, single lab, limited mechanistic depth\",\n      \"pmids\": [\"40664041\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"GAS2L3 is a DREAM complex target gene that encodes a cytoskeletal crosslinker with CH (actin-binding) and GAR (microtubule-binding) domains; it localizes to the spindle midzone and midbody where it bundles F-actin and microtubules, interacts with the chromosomal passenger complex (CPC) via its GAR domain binding borealin and survivin, undergoes APC/C(Cdh1)-mediated ubiquitin proteolysis and Cdk1 phosphorylation to control its mitotic abundance, and at the midbody constriction zone forms IDR-driven liquid-liquid phase separation condensates that scaffold CHMP4B recruitment to drive cytokinetic abscission; loss of GAS2L3 causes chromosome segregation errors, cytokinesis failure, and—in vivo—cardiomyocyte binucleation leading to neonatal heart failure.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"GAS2L3 is a cell-cycle-regulated cytoskeletal crosslinker that acts at the spindle midzone and midbody to ensure faithful chromosome segregation and cytokinetic abscission [#0]. It directly binds and bundles both microtubules and F-actin in vitro and is transcriptionally controlled as a DREAM complex target, with loss of function producing chromosome segregation defects, multinucleation, and aneuploidy [#0]. Its mitotic abundance is tightly timed: GAS2L3 is phosphorylated by Cdk1 in mitosis and targeted for degradation by APC/C(Cdh1) but not APC/C(Cdc20), and late in cytokinesis it concentrates at constriction sites of the intercellular bridge, where overexpression blocks abscission [#1]. GAS2L3 functions as a downstream effector of the chromosomal passenger complex, its conserved GAR domain binding the borealin C-terminus and survivin N-terminus, an interaction required for recruitment to the constriction zone [#2]. At the midbody it drives abscission by forming intrinsically disordered region (IDR)-dependent liquid-liquid phase separation condensates that scaffold CHMP4B condensate assembly; IDR deletion or knockdown causes defective cytokinesis and G1 arrest [#7]. In vivo, GAS2L3 deficiency causes premature cardiomyocyte binucleation from incomplete cytokinesis, unresolved midbodies, and a p53/p21 program, leading to neonatal heart failure in knockout mice [#5], and is required for normal brain morphogenesis and cell proliferation in zebrafish [#4].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Established GAS2L3 as a DREAM-controlled midzone/midbody protein whose loss disrupts genome stability, defining its core role in mitosis and cytokinesis.\",\n      \"evidence\": \"RNAi knockdown with live imaging, in vitro microtubule/actin bundling assays, and immunofluorescence localization\",\n      \"pmids\": [\"22344256\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not resolve how GAS2L3 is recruited to the midbody\", \"Molecular partners at the midzone not identified\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Placed GAS2L3 downstream of necdin in a hematopoietic stem cell genotoxic stress response, hinting at a role beyond cell-cycle mechanics.\",\n      \"evidence\": \"Genetic epistasis using necdin-null HSC transplantation with irradiation/chemotherapy challenge\",\n      \"pmids\": [\"22776820\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"GAS2L3-specific molecular mechanism not directly dissected\", \"Inferred by epistasis in a single study\", \"Link to its mitotic function unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Defined how GAS2L3 abundance is timed across the cell cycle, showing it is a Cdk1 substrate and an APC/C(Cdh1)-specific degradation target, and that its levels must be controlled for abscission to proceed.\",\n      \"evidence\": \"Cell-free ubiquitination assays in frog egg and human extracts, Cdk1 phosphorylation assay, and overexpression abscission assay\",\n      \"pmids\": [\"23469016\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cdk1 phosphosites and their functional consequence not mapped\", \"How degradation timing couples to abscission completion unresolved\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Identified the GAR domain as the CPC-binding module linking GAS2L3 to borealin and survivin, establishing it as a CPC effector recruited to the constriction zone.\",\n      \"evidence\": \"Pulldown/co-IP with CPC subunits, domain deletion/mutagenesis, and immunofluorescence localization\",\n      \"pmids\": [\"24571573\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Reciprocal validation and structural detail of the GAR-borealin/survivin interface not provided\", \"How CPC binding triggers downstream abscission events unknown\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Distinguished GAS2L3 from its paralogs G2L1/G2L2, showing it localizes to actin and microtubules but lacks EB-dependent microtubule-stabilizing activity, refining its functional niche.\",\n      \"evidence\": \"Fluorescence microscopy, live-cell imaging, and biochemical analysis of EB protein binding\",\n      \"pmids\": [\"24706950\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"GAS2L3-specific finding is largely negative\", \"Single-lab data on functional distinction from paralogs\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Demonstrated an in vivo developmental requirement for Gas2l3 in zebrafish brain morphogenesis and proliferation, confirmed by mRNA rescue.\",\n      \"evidence\": \"Morpholino knockdown with mRNA rescue and histological analysis in zebrafish\",\n      \"pmids\": [\"25131197\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanistic depth limited\", \"Whether the phenotype is purely cytokinesis-driven not established\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Provided definitive in vivo evidence that GAS2L3 cytokinesis function is essential in the heart, linking its loss to cardiomyocyte binucleation, a p53/p21 program, and neonatal lethality.\",\n      \"evidence\": \"Constitutive and cardiomyocyte-specific knockout mice with histology, immunofluorescence, and gene expression analysis\",\n      \"pmids\": [\"28698371\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism connecting failed abscission to p53 activation not detailed\", \"Tissue-selective vulnerability of cardiomyocytes unexplained\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed the biophysical mechanism of GAS2L3 at the midbody — IDR-driven phase separation that scaffolds CHMP4B condensates to accelerate abscission — and tied it to tumorigenicity.\",\n      \"evidence\": \"FRAP, in vitro droplet assays, IDR-deletion constructs, and knockdown with cytokinesis/cell-cycle readouts in HCC cells\",\n      \"pmids\": [\"41177429\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Single lab\", \"How IDR condensates physically promote CHMP4B/ESCRT polymerization not resolved\", \"Relationship between LLPS and the GAR-CPC recruitment pathway unclear\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended GAS2L3 beyond intracellular mitosis to an exosomal role promoting cancer-associated fibroblast migration and recruitment.\",\n      \"evidence\": \"Exosome proteomics and GAS2L3 loss-of-function fibroblast migration assays\",\n      \"pmids\": [\"40664041\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Limited mechanistic depth\", \"How a cytoskeletal/midbody protein acts extracellularly is unexplained\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the cell-cycle regulation (Cdk1/APC-Cdh1), CPC recruitment, and IDR-based phase separation are integrated into a single abscission program, and how this connects to the p53 stress responses seen in vivo, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No unified model linking degradation timing, CPC binding, and condensate formation\", \"Mechanism coupling failed cytokinesis to p53/p21 activation undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [2, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0, 1, 5]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"BIRC5\", \"CDCA8\", \"CHMP4B\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}