{"gene":"ASAP3","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":2008,"finding":"ASAP3 is an ArfGAP that uses Arf1, Arf5, and Arf6 as substrates in vitro; its pleckstrin homology (PH) domain stimulates catalytic activity by more than 100-fold and catalysis is further stimulated by phosphatidylinositol 4,5-bisphosphate.","method":"In vitro GTPase activity assay with substrate panel; PH domain mutagenesis/truncation","journal":"The Journal of Biological Chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro enzymatic reconstitution with domain mutagenesis; single lab but multiple orthogonal biochemical methods","pmids":["18400762"],"is_preprint":false},{"year":2008,"finding":"ASAP3 localizes to focal adhesions and circular dorsal ruffles but, unlike the related ASAP1, does not localize to invadopodia or podosomes.","method":"Fluorescence microscopy / subcellular localization in mammary carcinoma and glioblastoma cell lines","journal":"The Journal of Biological Chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct imaging with functional context, single lab, two cell lines","pmids":["18400762"],"is_preprint":false},{"year":2008,"finding":"Knockdown of ASAP3 reduces actin stress fibers, decreases phosphomyosin levels, and slows cell migration and invasion in mammary carcinoma cells; knockdown of ASAP1 had no effect on migration or invasion, demonstrating a non-redundant role for ASAP3.","method":"siRNA knockdown; actin/phosphomyosin immunostaining; migration and invasion assays","journal":"The Journal of Biological Chemistry","confidence":"High","confidence_rationale":"Tier 2 / Moderate — clean KD with multiple orthogonal cellular phenotype readouts; genetic epistasis comparison with ASAP1; single lab","pmids":["18400762"],"is_preprint":false},{"year":2004,"finding":"DDEFL1 (ASAP3) encodes a 903-amino acid protein with an ArfGAP domain and two ankyrin repeats, sharing 46% homology with DDEF/ASAP1; gene transfer of DDEFL1 promoted proliferation of cells lacking endogenous expression, and antisense oligonucleotide reduction of DDEFL1 inhibited growth of SNU475 HCC cells.","method":"cDNA cloning; gene transfer (overexpression); antisense S-oligonucleotide knockdown; cell proliferation assay","journal":"International Journal of Oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain-of-function and loss-of-function with proliferation phenotype, single lab","pmids":["14654939"],"is_preprint":false},{"year":2013,"finding":"Loss of ASAP3 destabilizes the cytoskeletal protein γ-actin-1 (ACTG1), linking ASAP3 to cytoskeletal maintenance and suppression of cell migration/invasion.","method":"siRNA knockdown of ASAP3; Western blot for ACTG1 protein levels; migration and invasion assays","journal":"Molecular Medicine Reports","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, Western blot + functional assays; mechanism of destabilization not fully resolved","pmids":["24284654"],"is_preprint":false},{"year":2017,"finding":"Conditional knockout of ASAP3 in mice causes elongation and stacking of microvilli in parietal cells associated with elevated GTP-bound Arf6, and substantially decreases gastric acid secretion; the small molecule QS11, an ASAP3 inhibitor, recapitulates this reduction in gastric acidity in vivo.","method":"Conditional knockout mouse model; electron microscopy of parietal cell microvilli; F-actin assembly assay; Arf6 GTP-loading assay; pharmacological inhibition with QS11 in vivo","journal":"Signal Transduction and Targeted Therapy","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — in vivo genetic KO plus pharmacological inhibition, multiple orthogonal readouts (structure, Arf6 activity, acid secretion), mechanistic pathway established","pmids":["29263912"],"is_preprint":false},{"year":2017,"finding":"DDEFL1 (ASAP3) knockdown in breast cancer cells down-regulates Rho, CDC42, and Rac1 mRNA and protein, providing a functional linkage between ASAP3/DDEFL1 and Rho GTPase signaling pathways.","method":"siRNA knockdown; Western blot and qRT-PCR for Rho family GTPases; apoptosis and invasion assays","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 3 / Weak — single lab, single knockdown approach; downstream pathway placement lacks direct mechanistic experiment","pmids":["29348842"],"is_preprint":false},{"year":2019,"finding":"ASAP3 is a direct transcriptional target of HIF-1α: HIF-1α binds directly to hypoxia response elements (HRE1 and/or HRE2) in the ASAP3 promoter under hypoxic conditions, inducing ASAP3 expression that drives migration, invasion, and tumor progression.","method":"Chromatin immunoprecipitation (ChIP); luciferase reporter assay; HIF-1α knockdown with ASAP3 overexpression rescue; wound-healing/migration assays; xenograft mouse model","journal":"OncoTargets and Therapy","confidence":"High","confidence_rationale":"Tier 2 / Moderate — ChIP + luciferase assay + in vivo rescue experiment; multiple orthogonal methods in single study establishing transcriptional regulation","pmids":["31410024"],"is_preprint":false},{"year":2019,"finding":"miR-143-3p directly targets ASAP3 mRNA; miR-143-3p mimics significantly reduced ASAP3 protein levels and attenuated cancer cell migration and invasion; ASAP3 knockdown alone recapitulated the anti-metastatic effect.","method":"miRNA mimic transfection; Western blot; siRNA knockdown; migration and invasion assays; bioinformatics target prediction","journal":"Cancer Science","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — functional validation of miRNA-target relationship by protein level reduction and phenotypic assay; direct 3'UTR luciferase experiment not mentioned in abstract","pmids":["30536996"],"is_preprint":false}],"current_model":"ASAP3 is a focal adhesion-associated ArfGAP (acting on Arf1, Arf5, and Arf6) whose PH domain and PI(4,5)P2 allosterically enhance catalytic activity; it promotes actin stress fiber formation, phosphomyosin accumulation, and cell migration/invasion by suppressing GTP-Arf6 levels, regulates parietal cell microvilli architecture and gastric acid secretion in vivo, is transcriptionally induced by HIF-1α via direct promoter binding, and is post-transcriptionally suppressed by miR-143-3p, with downstream effects linked to stabilization of γ-actin-1 and modulation of Rho/CDC42/Rac1 GTPase signaling."},"narrative":{"mechanistic_narrative":"ASAP3 is an ArfGAP that couples phosphoinositide-regulated Arf GTPase inactivation to actin cytoskeletal remodeling, cell migration, and invasion [PMID:18400762]. In vitro it hydrolyzes GTP on Arf1, Arf5, and Arf6, with its PH domain stimulating catalysis more than 100-fold and PI(4,5)P2 further enhancing activity, establishing it as a phosphoinositide-responsive GAP [PMID:18400762]. ASAP3 localizes to focal adhesions and circular dorsal ruffles, and its depletion reduces actin stress fibers and phosphomyosin while slowing migration and invasion in a manner non-redundant with the related ASAP1 [PMID:18400762]; loss of ASAP3 also destabilizes γ-actin-1 (ACTG1) and down-regulates Rho, CDC42, and Rac1, linking it to broader cytoskeletal GTPase signaling [PMID:24284654, PMID:29348842]. In vivo, conditional knockout in parietal cells elevates GTP-Arf6, causes microvillar elongation and stacking, and reduces gastric acid secretion, a phenotype recapitulated by the inhibitor QS11 [PMID:29263912]. ASAP3 expression is controlled at two levels: HIF-1α binds hypoxia response elements in its promoter to induce expression and drive tumor progression [PMID:31410024], while miR-143-3p targets its mRNA to suppress ASAP3 and attenuate migration and invasion [PMID:30536996].","teleology":[{"year":2004,"claim":"Established ASAP3 (DDEFL1) as a distinct ArfGAP-domain, ankyrin-repeat protein related to ASAP1 with a role in supporting cell proliferation, raising the question of its molecular activity.","evidence":"cDNA cloning, overexpression and antisense knockdown with proliferation assay in HCC cells","pmids":["14654939"],"confidence":"Medium","gaps":["GAP enzymatic activity not directly demonstrated","substrate Arf specificity unknown","mechanism linking expression to proliferation unresolved"]},{"year":2008,"claim":"Defined ASAP3 as a catalytically active ArfGAP whose activity is allosterically controlled by its PH domain and PI(4,5)P2, answering what biochemical reaction it performs and how it is regulated.","evidence":"in vitro GTPase activity assays across an Arf substrate panel with PH domain mutagenesis/truncation","pmids":["18400762"],"confidence":"High","gaps":["physiological substrate among Arf1/5/6 not established in cells","structural basis of PH/PI(4,5)P2 stimulation not solved"]},{"year":2008,"claim":"Placed ASAP3 at focal adhesions and dorsal ruffles and showed it is required, non-redundantly with ASAP1, for stress fiber formation, phosphomyosin accumulation, and migration/invasion, connecting GAP activity to cytoskeletal output.","evidence":"subcellular imaging plus siRNA knockdown with actin/phosphomyosin staining and migration/invasion assays in carcinoma cells","pmids":["18400762"],"confidence":"High","gaps":["which Arf substrate mediates the cytoskeletal phenotype not pinpointed","single-lab, limited cell lines"]},{"year":2013,"claim":"Identified γ-actin-1 (ACTG1) stabilization as a downstream consequence of ASAP3, providing a molecular link between ASAP3 and cytoskeletal maintenance.","evidence":"siRNA knockdown with ACTG1 Western blot and migration/invasion assays","pmids":["24284654"],"confidence":"Medium","gaps":["mechanism of ACTG1 destabilization not resolved","whether effect is direct or via Arf/GTPase signaling unknown"]},{"year":2017,"claim":"Demonstrated in vivo that ASAP3 controls Arf6 GTP-loading, parietal cell microvillar architecture, and gastric acid secretion, extending its role from cancer cells to organ physiology and validating it as a druggable target.","evidence":"conditional knockout mouse, EM of microvilli, Arf6 GTP-loading and F-actin assays, and pharmacological inhibition with QS11 in vivo","pmids":["29263912"],"confidence":"High","gaps":["selectivity of QS11 not fully characterized","link between microvillar defect and acid secretion mechanistically incomplete"]},{"year":2017,"claim":"Connected ASAP3 to Rho-family GTPase signaling by showing knockdown reduces Rho, CDC42, and Rac1, broadening its proposed signaling reach.","evidence":"siRNA knockdown with Western blot/qRT-PCR for Rho GTPases and apoptosis/invasion assays in breast cancer cells","pmids":["29348842"],"confidence":"Medium","gaps":["no direct mechanistic experiment placing ASAP3 upstream of Rho GTPases","single knockdown approach"]},{"year":2019,"claim":"Resolved upstream control of ASAP3 expression, showing HIF-1α directly binds its promoter to induce ASAP3 and drive tumor progression under hypoxia.","evidence":"ChIP, luciferase reporter, HIF-1α knockdown with ASAP3 rescue, migration assays, and xenograft model","pmids":["31410024"],"confidence":"High","gaps":["relative contribution of HRE1 vs HRE2 not fully dissected","whether hypoxic induction operates in normal physiology unknown"]},{"year":2019,"claim":"Identified miR-143-3p as a post-transcriptional repressor of ASAP3, defining a second regulatory axis that constrains ASAP3-driven metastatic behavior.","evidence":"miRNA mimic transfection with Western blot, siRNA knockdown, and migration/invasion assays","pmids":["30536996"],"confidence":"Medium","gaps":["direct 3'UTR luciferase validation not reported in abstract","in vivo relevance of the miRNA axis untested"]},{"year":null,"claim":"The physiological Arf substrate(s) and structural basis by which ASAP3 transduces phosphoinositide signals into cytoskeletal and Rho-GTPase remodeling remain incompletely defined.","evidence":"","pmids":[],"confidence":"Medium","gaps":["no structure of ASAP3 or its complexes","direct mechanism linking Arf6 inactivation to Rho/CDC42/Rac1 and ACTG1 unresolved","no reported direct physical partners beyond Arf substrates"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,5]},{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[1,2]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[0,5]}],"complexes":[],"partners":["ARF6","ARF1","ARF5"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8TDY4","full_name":"Arf-GAP with SH3 domain, ANK repeat and PH domain-containing protein 3","aliases":["Development and differentiation-enhancing factor-like 1","Protein up-regulated in liver cancer 1"],"length_aa":903,"mass_kda":99.2,"function":"Promotes cell proliferation","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q8TDY4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ASAP3","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ASAP3","total_profiled":1310},"omim":[{"mim_id":"616594","title":"ARF GTPase-ACTIVATING PROTEIN WITH SH3 DOMAIN, ANKYRIN REPEAT, AND PH DOMAIN 3; ASAP3","url":"https://www.omim.org/entry/616594"},{"mim_id":"600464","title":"ADP-RIBOSYLATION FACTOR 6; ARF6","url":"https://www.omim.org/entry/600464"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Vesicles","reliability":"Supported"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ASAP3"},"hgnc":{"alias_symbol":["FLJ20199","UPLC1","CENTB6"],"prev_symbol":["DDEFL1"]},"alphafold":{"accession":"Q8TDY4","domains":[{"cath_id":"1.20.1270.60","chopping":"6-255","consensus_level":"high","plddt":89.9374,"start":6,"end":255},{"cath_id":"2.30.29.30","chopping":"302-399","consensus_level":"high","plddt":88.1478,"start":302,"end":399},{"cath_id":"1.10.220.150","chopping":"438-535","consensus_level":"high","plddt":92.6751,"start":438,"end":535},{"cath_id":"1.25.40.20","chopping":"547-678","consensus_level":"high","plddt":91.2168,"start":547,"end":678}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TDY4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TDY4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TDY4-F1-predicted_aligned_error_v6.png","plddt_mean":73.81},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ASAP3","jax_strain_url":"https://www.jax.org/strain/search?query=ASAP3"},"sequence":{"accession":"Q8TDY4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8TDY4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8TDY4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TDY4"}},"corpus_meta":[{"pmid":"30536996","id":"PMC_30536996","title":"MicroRNA-143-3p inhibits colorectal cancer metastases by targeting ITGA6 and ASAP3.","date":"2019","source":"Cancer science","url":"https://pubmed.ncbi.nlm.nih.gov/30536996","citation_count":60,"is_preprint":false},{"pmid":"18400762","id":"PMC_18400762","title":"ASAP3 is a focal adhesion-associated Arf GAP that functions in cell migration and invasion.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18400762","citation_count":56,"is_preprint":false},{"pmid":"14654939","id":"PMC_14654939","title":"Isolation of development and differentiation enhancing factor-like 1 (DDEFL1) as a drug target for hepatocellular carcinomas.","date":"2004","source":"International journal of oncology","url":"https://pubmed.ncbi.nlm.nih.gov/14654939","citation_count":39,"is_preprint":false},{"pmid":"24284654","id":"PMC_24284654","title":"Loss of ASAP3 destabilizes cytoskeletal protein ACTG1 to suppress cancer cell migration.","date":"2013","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/24284654","citation_count":30,"is_preprint":false},{"pmid":"35256624","id":"PMC_35256624","title":"A red fluorescent protein with improved monomericity enables ratiometric voltage imaging with ASAP3.","date":"2022","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/35256624","citation_count":17,"is_preprint":false},{"pmid":"24078447","id":"PMC_24078447","title":"ASAP3 expression in non-small cell lung cancer: association with cancer development and patients' clinical outcome.","date":"2014","source":"Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine","url":"https://pubmed.ncbi.nlm.nih.gov/24078447","citation_count":12,"is_preprint":false},{"pmid":"31410024","id":"PMC_31410024","title":"ASAP3 is a downstream target of HIF-1α and is critical for progression of lung adenocarcinoma.","date":"2019","source":"OncoTargets and therapy","url":"https://pubmed.ncbi.nlm.nih.gov/31410024","citation_count":6,"is_preprint":false},{"pmid":"36382054","id":"PMC_36382054","title":"The expression of ASAP3 and NOTCH3 and the clinicopathological characteristics of adult glioma patients.","date":"2022","source":"Open medicine (Warsaw, Poland)","url":"https://pubmed.ncbi.nlm.nih.gov/36382054","citation_count":4,"is_preprint":false},{"pmid":"29348842","id":"PMC_29348842","title":"DDEFL1 correlated with Rho GTPases activity in breast cancer.","date":"2017","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/29348842","citation_count":4,"is_preprint":false},{"pmid":"29263912","id":"PMC_29263912","title":"ASAP3 regulates microvilli structure in parietal cells and presents intervention target for gastric acidity.","date":"2017","source":"Signal transduction and targeted therapy","url":"https://pubmed.ncbi.nlm.nih.gov/29263912","citation_count":3,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.08.669310","title":"Absolute Membrane Potential Recording with ASAP-Type Genetically Encoded Voltage Indicators Using Fluorescence Lifetime Imaging","date":"2025-08-12","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.08.669310","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.06.21.599617","title":"Improving positively tuned voltage indicators for faster kinetics and higher contrast","date":"2024-06-25","source":"bioRxiv","url":"https://doi.org/10.1101/2024.06.21.599617","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7506,"output_tokens":2152,"usd":0.027399,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9194,"output_tokens":2911,"usd":0.059373,"stage2_stop_reason":"end_turn"},"total_usd":0.086772,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2008,\n      \"finding\": \"ASAP3 is an ArfGAP that uses Arf1, Arf5, and Arf6 as substrates in vitro; its pleckstrin homology (PH) domain stimulates catalytic activity by more than 100-fold and catalysis is further stimulated by phosphatidylinositol 4,5-bisphosphate.\",\n      \"method\": \"In vitro GTPase activity assay with substrate panel; PH domain mutagenesis/truncation\",\n      \"journal\": \"The Journal of Biological Chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro enzymatic reconstitution with domain mutagenesis; single lab but multiple orthogonal biochemical methods\",\n      \"pmids\": [\"18400762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"ASAP3 localizes to focal adhesions and circular dorsal ruffles but, unlike the related ASAP1, does not localize to invadopodia or podosomes.\",\n      \"method\": \"Fluorescence microscopy / subcellular localization in mammary carcinoma and glioblastoma cell lines\",\n      \"journal\": \"The Journal of Biological Chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct imaging with functional context, single lab, two cell lines\",\n      \"pmids\": [\"18400762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Knockdown of ASAP3 reduces actin stress fibers, decreases phosphomyosin levels, and slows cell migration and invasion in mammary carcinoma cells; knockdown of ASAP1 had no effect on migration or invasion, demonstrating a non-redundant role for ASAP3.\",\n      \"method\": \"siRNA knockdown; actin/phosphomyosin immunostaining; migration and invasion assays\",\n      \"journal\": \"The Journal of Biological Chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KD with multiple orthogonal cellular phenotype readouts; genetic epistasis comparison with ASAP1; single lab\",\n      \"pmids\": [\"18400762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"DDEFL1 (ASAP3) encodes a 903-amino acid protein with an ArfGAP domain and two ankyrin repeats, sharing 46% homology with DDEF/ASAP1; gene transfer of DDEFL1 promoted proliferation of cells lacking endogenous expression, and antisense oligonucleotide reduction of DDEFL1 inhibited growth of SNU475 HCC cells.\",\n      \"method\": \"cDNA cloning; gene transfer (overexpression); antisense S-oligonucleotide knockdown; cell proliferation assay\",\n      \"journal\": \"International Journal of Oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain-of-function and loss-of-function with proliferation phenotype, single lab\",\n      \"pmids\": [\"14654939\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Loss of ASAP3 destabilizes the cytoskeletal protein γ-actin-1 (ACTG1), linking ASAP3 to cytoskeletal maintenance and suppression of cell migration/invasion.\",\n      \"method\": \"siRNA knockdown of ASAP3; Western blot for ACTG1 protein levels; migration and invasion assays\",\n      \"journal\": \"Molecular Medicine Reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, Western blot + functional assays; mechanism of destabilization not fully resolved\",\n      \"pmids\": [\"24284654\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Conditional knockout of ASAP3 in mice causes elongation and stacking of microvilli in parietal cells associated with elevated GTP-bound Arf6, and substantially decreases gastric acid secretion; the small molecule QS11, an ASAP3 inhibitor, recapitulates this reduction in gastric acidity in vivo.\",\n      \"method\": \"Conditional knockout mouse model; electron microscopy of parietal cell microvilli; F-actin assembly assay; Arf6 GTP-loading assay; pharmacological inhibition with QS11 in vivo\",\n      \"journal\": \"Signal Transduction and Targeted Therapy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — in vivo genetic KO plus pharmacological inhibition, multiple orthogonal readouts (structure, Arf6 activity, acid secretion), mechanistic pathway established\",\n      \"pmids\": [\"29263912\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"DDEFL1 (ASAP3) knockdown in breast cancer cells down-regulates Rho, CDC42, and Rac1 mRNA and protein, providing a functional linkage between ASAP3/DDEFL1 and Rho GTPase signaling pathways.\",\n      \"method\": \"siRNA knockdown; Western blot and qRT-PCR for Rho family GTPases; apoptosis and invasion assays\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, single knockdown approach; downstream pathway placement lacks direct mechanistic experiment\",\n      \"pmids\": [\"29348842\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"ASAP3 is a direct transcriptional target of HIF-1α: HIF-1α binds directly to hypoxia response elements (HRE1 and/or HRE2) in the ASAP3 promoter under hypoxic conditions, inducing ASAP3 expression that drives migration, invasion, and tumor progression.\",\n      \"method\": \"Chromatin immunoprecipitation (ChIP); luciferase reporter assay; HIF-1α knockdown with ASAP3 overexpression rescue; wound-healing/migration assays; xenograft mouse model\",\n      \"journal\": \"OncoTargets and Therapy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP + luciferase assay + in vivo rescue experiment; multiple orthogonal methods in single study establishing transcriptional regulation\",\n      \"pmids\": [\"31410024\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"miR-143-3p directly targets ASAP3 mRNA; miR-143-3p mimics significantly reduced ASAP3 protein levels and attenuated cancer cell migration and invasion; ASAP3 knockdown alone recapitulated the anti-metastatic effect.\",\n      \"method\": \"miRNA mimic transfection; Western blot; siRNA knockdown; migration and invasion assays; bioinformatics target prediction\",\n      \"journal\": \"Cancer Science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — functional validation of miRNA-target relationship by protein level reduction and phenotypic assay; direct 3'UTR luciferase experiment not mentioned in abstract\",\n      \"pmids\": [\"30536996\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ASAP3 is a focal adhesion-associated ArfGAP (acting on Arf1, Arf5, and Arf6) whose PH domain and PI(4,5)P2 allosterically enhance catalytic activity; it promotes actin stress fiber formation, phosphomyosin accumulation, and cell migration/invasion by suppressing GTP-Arf6 levels, regulates parietal cell microvilli architecture and gastric acid secretion in vivo, is transcriptionally induced by HIF-1α via direct promoter binding, and is post-transcriptionally suppressed by miR-143-3p, with downstream effects linked to stabilization of γ-actin-1 and modulation of Rho/CDC42/Rac1 GTPase signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ASAP3 is an ArfGAP that couples phosphoinositide-regulated Arf GTPase inactivation to actin cytoskeletal remodeling, cell migration, and invasion [#0, #2]. In vitro it hydrolyzes GTP on Arf1, Arf5, and Arf6, with its PH domain stimulating catalysis more than 100-fold and PI(4,5)P2 further enhancing activity, establishing it as a phosphoinositide-responsive GAP [#0]. ASAP3 localizes to focal adhesions and circular dorsal ruffles, and its depletion reduces actin stress fibers and phosphomyosin while slowing migration and invasion in a manner non-redundant with the related ASAP1 [#1, #2]; loss of ASAP3 also destabilizes \\u03b3-actin-1 (ACTG1) and down-regulates Rho, CDC42, and Rac1, linking it to broader cytoskeletal GTPase signaling [#4, #6]. In vivo, conditional knockout in parietal cells elevates GTP-Arf6, causes microvillar elongation and stacking, and reduces gastric acid secretion, a phenotype recapitulated by the inhibitor QS11 [#5]. ASAP3 expression is controlled at two levels: HIF-1\\u03b1 binds hypoxia response elements in its promoter to induce expression and drive tumor progression [#7], while miR-143-3p targets its mRNA to suppress ASAP3 and attenuate migration and invasion [#8].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established ASAP3 (DDEFL1) as a distinct ArfGAP-domain, ankyrin-repeat protein related to ASAP1 with a role in supporting cell proliferation, raising the question of its molecular activity.\",\n      \"evidence\": \"cDNA cloning, overexpression and antisense knockdown with proliferation assay in HCC cells\",\n      \"pmids\": [\n        \"14654939\"\n      ],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"GAP enzymatic activity not directly demonstrated\",\n        \"substrate Arf specificity unknown\",\n        \"mechanism linking expression to proliferation unresolved\"\n      ]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Defined ASAP3 as a catalytically active ArfGAP whose activity is allosterically controlled by its PH domain and PI(4,5)P2, answering what biochemical reaction it performs and how it is regulated.\",\n      \"evidence\": \"in vitro GTPase activity assays across an Arf substrate panel with PH domain mutagenesis/truncation\",\n      \"pmids\": [\n        \"18400762\"\n      ],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"physiological substrate among Arf1/5/6 not established in cells\",\n        \"structural basis of PH/PI(4,5)P2 stimulation not solved\"\n      ]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Placed ASAP3 at focal adhesions and dorsal ruffles and showed it is required, non-redundantly with ASAP1, for stress fiber formation, phosphomyosin accumulation, and migration/invasion, connecting GAP activity to cytoskeletal output.\",\n      \"evidence\": \"subcellular imaging plus siRNA knockdown with actin/phosphomyosin staining and migration/invasion assays in carcinoma cells\",\n      \"pmids\": [\n        \"18400762\"\n      ],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"which Arf substrate mediates the cytoskeletal phenotype not pinpointed\",\n        \"single-lab, limited cell lines\"\n      ]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Identified \\u03b3-actin-1 (ACTG1) stabilization as a downstream consequence of ASAP3, providing a molecular link between ASAP3 and cytoskeletal maintenance.\",\n      \"evidence\": \"siRNA knockdown with ACTG1 Western blot and migration/invasion assays\",\n      \"pmids\": [\n        \"24284654\"\n      ],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"mechanism of ACTG1 destabilization not resolved\",\n        \"whether effect is direct or via Arf/GTPase signaling unknown\"\n      ]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Demonstrated in vivo that ASAP3 controls Arf6 GTP-loading, parietal cell microvillar architecture, and gastric acid secretion, extending its role from cancer cells to organ physiology and validating it as a druggable target.\",\n      \"evidence\": \"conditional knockout mouse, EM of microvilli, Arf6 GTP-loading and F-actin assays, and pharmacological inhibition with QS11 in vivo\",\n      \"pmids\": [\n        \"29263912\"\n      ],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"selectivity of QS11 not fully characterized\",\n        \"link between microvillar defect and acid secretion mechanistically incomplete\"\n      ]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Connected ASAP3 to Rho-family GTPase signaling by showing knockdown reduces Rho, CDC42, and Rac1, broadening its proposed signaling reach.\",\n      \"evidence\": \"siRNA knockdown with Western blot/qRT-PCR for Rho GTPases and apoptosis/invasion assays in breast cancer cells\",\n      \"pmids\": [\n        \"29348842\"\n      ],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"no direct mechanistic experiment placing ASAP3 upstream of Rho GTPases\",\n        \"single knockdown approach\"\n      ]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Resolved upstream control of ASAP3 expression, showing HIF-1\\u03b1 directly binds its promoter to induce ASAP3 and drive tumor progression under hypoxia.\",\n      \"evidence\": \"ChIP, luciferase reporter, HIF-1\\u03b1 knockdown with ASAP3 rescue, migration assays, and xenograft model\",\n      \"pmids\": [\n        \"31410024\"\n      ],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"relative contribution of HRE1 vs HRE2 not fully dissected\",\n        \"whether hypoxic induction operates in normal physiology unknown\"\n      ]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identified miR-143-3p as a post-transcriptional repressor of ASAP3, defining a second regulatory axis that constrains ASAP3-driven metastatic behavior.\",\n      \"evidence\": \"miRNA mimic transfection with Western blot, siRNA knockdown, and migration/invasion assays\",\n      \"pmids\": [\n        \"30536996\"\n      ],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"direct 3'UTR luciferase validation not reported in abstract\",\n        \"in vivo relevance of the miRNA axis untested\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The physiological Arf substrate(s) and structural basis by which ASAP3 transduces phosphoinositide signals into cytoskeletal and Rho-GTPase remodeling remain incompletely defined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"no structure of ASAP3 or its complexes\",\n        \"direct mechanism linking Arf6 inactivation to Rho/CDC42/Rac1 and ACTG1 unresolved\",\n        \"no reported direct physical partners beyond Arf substrates\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 5]},\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [1, 2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [0, 5]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"ARF6\",\n      \"ARF1\",\n      \"ARF5\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"faith_supported":4,"faith_total":5,"faith_pct":80.0}}